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* [PATCH v12 0/9] Add arc4random support
@ 2022-07-22 12:21 Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417) Adhemerval Zanella
                   ` (9 more replies)
  0 siblings, 10 replies; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy

This patch adds the arc4random, arc4random_buf, and arc4random_uniform
functions along with optimized versions for x86_64 (sse2 and avx2),
aarch64, powerpc64 (power8), and s390x (vx).

The generic implementation is based on scalar Chacha20, with a per
thread state cache allocated lazily.  The internal state keeps a 256
bytes buffer (8 ChaCha20 blocks) plus the cipher state, which allows
to better use the vectorized optimized version.  It would be possible
to use just 128 bytes, but it would require to rewrite the AVX2
optimization (and possible it would lower performance slight).

The initial state and reseed uses getrandom or /dev/urandom as
fallback and reseeds the internal state on every 16MB of consumed
entropy.

There is no fork detection, the internal state is reset only for
fork and _Fork calls.  It does not handle direct clone calls nor vfork.

Although it is lock-free, arc4random is still not async-signal-safe
(the per thread state is not updated atomically), although it is
async-cancel-safe.

The generic ChaCha20 implementation is based on the RFC8439 [1] without
the last XOR step.   Since the input stream will either zero bytes
(initial state) or the PRNG output itself this step does not add any
extra entropy.

The optimized ChaCha20 implementations for x86_64, aarch64, powerpc64,
and s390x use vectorized instruction and they are based on libgcrypt
code.

ChaCha20 is used because is the standard cipher used on different
arc4random implementation (BSDs, MacOSX), and recently on Linux random
subsystem.  It also offers a very cheap rekey, which uses periodically
uses kernel entropy to improve randomness;  it is also simpler than AES,
and shows better performance when no specialized instructions are
present.

[1] https://sourceware.org/pipermail/libc-alpha/2018-June/094879.html

v12:
* Assume contant buffer size fro chacha20_crypt.

v11:
* Fixed Copyright headers.

v10:
* Fixed x86_64 building with different minimum ISA levels.
* Fixed documentation.

v9:
* Reword NEWS entry, internal comments, and style.
* Use explicit_bzero in more places.
* Do not include bits/stdint-uintn.h on stdint.h.
* Fixed documentation.

v8:
* Remove final register state clearing from optimized routines.

v7:
* Merged the lock-free TCV optimization on first patch.
* Added the original Copyright headers from libgcrypt on imported
  implementations.
* Fixed typos and wording.
* Use DO_NOT_OPTIMIZE_OUT from hash benchmark.

v6:
* Replace array usage with variables and make compiler add hardening if
  required to cleanup any internal state.  It also shows slight better
  performance.
* Add tests for arc4random and arc4random_uniform on thread and fork.
* Fixed documentation to state the functiosn as async-signal-unsafe.

v5:
* Added documentation.
* Fixed typos.

v4:
* Fixed typos and expanded comments.
* Fixed powerpc multi-arch organization.

v3:
* Add per-thread cache to remove the lock usage.  It should improve both
  performance and scalability.
* Improve benchmark precision.
* Fixed Hurd test build.

v2:
* Removed the last XOR operation on ChaCha20 implementation (it does
  not much on arc4random usage).
* Add tst-arc4random-chacha20.c and refactor to check against the
  expected implementation.
* Fixed aarch64 implementation (a last change to move symbols to hidden
  did not change the relocation to use it as well).
* Refactor x86 SSSE3 to SSE2.
* Fixed powerpc64 implementation on BE (use the correct macro to check
  for endianess instead the ones from libgcrpyt).
* Add s390x optimized ChaCha20 implementation.

Adhemerval Zanella Netto (9):
  stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ
    #4417)
  stdlib: Add arc4random tests
  benchtests: Add arc4random benchtest
  aarch64: Add optimized chacha20
  x86: Add SSE2 optimized chacha20
  x86: Add AVX2 optimized chacha20
  powerpc64: Add optimized chacha20
  s390x: Add optimized chacha20
  manual: Add documentation for arc4random functions

 LICENSES                                      |  23 +
 NEWS                                          |   4 +
 benchtests/Makefile                           |   5 +-
 benchtests/bench-arc4random.c                 | 218 +++++++
 benchtests/bench-hash-funcs-kernel.h          |   1 +
 benchtests/bench-hash-funcs.c                 |   2 -
 benchtests/bench-util.h                       |   7 +
 include/stdlib.h                              |  12 +
 malloc/thread-freeres.c                       |   2 +-
 manual/math.texi                              |  46 ++
 nptl/allocatestack.c                          |   3 +-
 stdlib/Makefile                               |   9 +
 stdlib/Versions                               |   5 +
 stdlib/arc4random.c                           | 208 +++++++
 stdlib/arc4random.h                           |  48 ++
 stdlib/arc4random_uniform.c                   | 140 +++++
 stdlib/chacha20.c                             | 183 ++++++
 stdlib/stdlib.h                               |  13 +
 stdlib/tst-arc4random-chacha20.c              | 167 +++++
 stdlib/tst-arc4random-fork.c                  | 198 ++++++
 stdlib/tst-arc4random-stats.c                 | 147 +++++
 stdlib/tst-arc4random-thread.c                | 341 +++++++++++
 sysdeps/aarch64/Makefile                      |   4 +
 sysdeps/aarch64/chacha20-aarch64.S            | 314 ++++++++++
 sysdeps/aarch64/chacha20_arch.h               |  39 ++
 sysdeps/generic/chacha20_arch.h               |  23 +
 sysdeps/generic/not-cancel.h                  |   2 +
 sysdeps/generic/tls-internal-struct.h         |   1 +
 sysdeps/generic/tls-internal.c                |  18 +
 sysdeps/generic/tls-internal.h                |   7 +-
 sysdeps/mach/hurd/_Fork.c                     |   2 +
 sysdeps/mach/hurd/i386/libc.abilist           |   3 +
 sysdeps/mach/hurd/not-cancel.h                |   3 +
 sysdeps/nptl/_Fork.c                          |   2 +
 .../powerpc/powerpc64/be/multiarch/Makefile   |   4 +
 .../powerpc64/be/multiarch/chacha20-ppc.c     |   1 +
 .../powerpc64/be/multiarch/chacha20_arch.h    |  41 ++
 sysdeps/powerpc/powerpc64/power8/Makefile     |   5 +
 .../powerpc/powerpc64/power8/chacha20-ppc.c   | 256 ++++++++
 .../powerpc/powerpc64/power8/chacha20_arch.h  |  36 ++
 sysdeps/s390/s390-64/Makefile                 |   6 +
 sysdeps/s390/s390-64/chacha20-s390x.S         | 573 ++++++++++++++++++
 sysdeps/s390/s390-64/chacha20_arch.h          |  44 ++
 sysdeps/unix/sysv/linux/aarch64/libc.abilist  |   3 +
 sysdeps/unix/sysv/linux/alpha/libc.abilist    |   3 +
 sysdeps/unix/sysv/linux/arc/libc.abilist      |   3 +
 sysdeps/unix/sysv/linux/arm/be/libc.abilist   |   3 +
 sysdeps/unix/sysv/linux/arm/le/libc.abilist   |   3 +
 sysdeps/unix/sysv/linux/csky/libc.abilist     |   3 +
 sysdeps/unix/sysv/linux/hppa/libc.abilist     |   3 +
 sysdeps/unix/sysv/linux/i386/libc.abilist     |   3 +
 sysdeps/unix/sysv/linux/ia64/libc.abilist     |   3 +
 .../sysv/linux/m68k/coldfire/libc.abilist     |   3 +
 .../unix/sysv/linux/m68k/m680x0/libc.abilist  |   3 +
 .../sysv/linux/microblaze/be/libc.abilist     |   3 +
 .../sysv/linux/microblaze/le/libc.abilist     |   3 +
 .../sysv/linux/mips/mips32/fpu/libc.abilist   |   3 +
 .../sysv/linux/mips/mips32/nofpu/libc.abilist |   3 +
 .../sysv/linux/mips/mips64/n32/libc.abilist   |   3 +
 .../sysv/linux/mips/mips64/n64/libc.abilist   |   3 +
 sysdeps/unix/sysv/linux/nios2/libc.abilist    |   3 +
 sysdeps/unix/sysv/linux/not-cancel.h          |   7 +
 sysdeps/unix/sysv/linux/or1k/libc.abilist     |   3 +
 .../linux/powerpc/powerpc32/fpu/libc.abilist  |   3 +
 .../powerpc/powerpc32/nofpu/libc.abilist      |   3 +
 .../linux/powerpc/powerpc64/be/libc.abilist   |   3 +
 .../linux/powerpc/powerpc64/le/libc.abilist   |   3 +
 .../unix/sysv/linux/riscv/rv32/libc.abilist   |   3 +
 .../unix/sysv/linux/riscv/rv64/libc.abilist   |   3 +
 .../unix/sysv/linux/s390/s390-32/libc.abilist |   3 +
 .../unix/sysv/linux/s390/s390-64/libc.abilist |   3 +
 sysdeps/unix/sysv/linux/sh/be/libc.abilist    |   3 +
 sysdeps/unix/sysv/linux/sh/le/libc.abilist    |   3 +
 .../sysv/linux/sparc/sparc32/libc.abilist     |   3 +
 .../sysv/linux/sparc/sparc64/libc.abilist     |   3 +
 sysdeps/unix/sysv/linux/tls-internal.c        |  39 +-
 sysdeps/unix/sysv/linux/tls-internal.h        |   8 +-
 .../unix/sysv/linux/x86_64/64/libc.abilist    |   3 +
 .../unix/sysv/linux/x86_64/x32/libc.abilist   |   3 +
 sysdeps/x86_64/Makefile                       |   7 +
 sysdeps/x86_64/chacha20-amd64-avx2.S          | 328 ++++++++++
 sysdeps/x86_64/chacha20-amd64-sse2.S          | 311 ++++++++++
 sysdeps/x86_64/chacha20_arch.h                |  54 ++
 83 files changed, 4001 insertions(+), 18 deletions(-)
 create mode 100644 benchtests/bench-arc4random.c
 create mode 100644 stdlib/arc4random.c
 create mode 100644 stdlib/arc4random.h
 create mode 100644 stdlib/arc4random_uniform.c
 create mode 100644 stdlib/chacha20.c
 create mode 100644 stdlib/tst-arc4random-chacha20.c
 create mode 100644 stdlib/tst-arc4random-fork.c
 create mode 100644 stdlib/tst-arc4random-stats.c
 create mode 100644 stdlib/tst-arc4random-thread.c
 create mode 100644 sysdeps/aarch64/chacha20-aarch64.S
 create mode 100644 sysdeps/aarch64/chacha20_arch.h
 create mode 100644 sysdeps/generic/chacha20_arch.h
 create mode 100644 sysdeps/powerpc/powerpc64/be/multiarch/Makefile
 create mode 100644 sysdeps/powerpc/powerpc64/be/multiarch/chacha20-ppc.c
 create mode 100644 sysdeps/powerpc/powerpc64/be/multiarch/chacha20_arch.h
 create mode 100644 sysdeps/powerpc/powerpc64/power8/chacha20-ppc.c
 create mode 100644 sysdeps/powerpc/powerpc64/power8/chacha20_arch.h
 create mode 100644 sysdeps/s390/s390-64/chacha20-s390x.S
 create mode 100644 sysdeps/s390/s390-64/chacha20_arch.h
 create mode 100644 sysdeps/x86_64/chacha20-amd64-avx2.S
 create mode 100644 sysdeps/x86_64/chacha20-amd64-sse2.S
 create mode 100644 sysdeps/x86_64/chacha20_arch.h

-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417)
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
@ 2022-07-22 12:21 ` Adhemerval Zanella
  2022-07-22 12:35   ` Florian Weimer
  2022-07-22 15:31   ` Zack Weinberg
  2022-07-22 12:21 ` [PATCH v12 2/9] stdlib: Add arc4random tests Adhemerval Zanella
                   ` (8 subsequent siblings)
  9 siblings, 2 replies; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy
  Cc: Adhemerval Zanella Netto, Yann Droneaud

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

The implementation is based on scalar Chacha20 with per-thread cache.
It uses getrandom or /dev/urandom as fallback to get the initial entropy,
and reseeds the internal state on every 16MB of consumed buffer.

To improve performance and lower memory consumption the per-thread cache
is allocated lazily on first arc4random functions call, and if the
memory allocation fails getentropy or /dev/urandom is used as fallback.
The cache is also cleared on thread exit iff it was initialized (so if
arc4random is not called it is not touched).

Although it is lock-free, arc4random is still not async-signal-safe
(the per thread state is not updated atomically).

The ChaCha20 implementation is based on RFC8439 [1], omitting the final
XOR of the keystream with the plaintext because the plaintext is a
stream of zeros.  This strategy is similar to what OpenBSD arc4random
does.

The arc4random_uniform is based on previous work by Florian Weimer,
where the algorithm is based on Jérémie Lumbroso paper Optimal Discrete
Uniform Generation from Coin Flips, and Applications (2013) [2], who
credits Donald E. Knuth and Andrew C. Yao, The complexity of nonuniform
random number generation (1976), for solving the general case.

The main advantage of this method is the that the unit of randomness is not
the uniform random variable (uint32_t), but a random bit.  It optimizes the
internal buffer sampling by initially consuming a 32-bit random variable
and then sampling byte per byte.  Depending of the upper bound requested,
it might lead to better CPU utilization.

Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu.

Co-authored-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Yann Droneaud <ydroneaud@opteya.com>

[1] https://datatracker.ietf.org/doc/html/rfc8439
[2] https://arxiv.org/pdf/1304.1916.pdf
---
 NEWS                                          |   4 +
 include/stdlib.h                              |  12 +
 malloc/thread-freeres.c                       |   2 +-
 nptl/allocatestack.c                          |   3 +-
 stdlib/Makefile                               |   2 +
 stdlib/Versions                               |   5 +
 stdlib/arc4random.c                           | 208 ++++++++++++++++++
 stdlib/arc4random.h                           |  48 ++++
 stdlib/arc4random_uniform.c                   | 140 ++++++++++++
 stdlib/chacha20.c                             | 179 +++++++++++++++
 stdlib/stdlib.h                               |  13 ++
 sysdeps/generic/not-cancel.h                  |   2 +
 sysdeps/generic/tls-internal-struct.h         |   1 +
 sysdeps/generic/tls-internal.c                |  18 ++
 sysdeps/generic/tls-internal.h                |   7 +-
 sysdeps/mach/hurd/_Fork.c                     |   2 +
 sysdeps/mach/hurd/i386/libc.abilist           |   3 +
 sysdeps/mach/hurd/not-cancel.h                |   3 +
 sysdeps/nptl/_Fork.c                          |   2 +
 sysdeps/unix/sysv/linux/aarch64/libc.abilist  |   3 +
 sysdeps/unix/sysv/linux/alpha/libc.abilist    |   3 +
 sysdeps/unix/sysv/linux/arc/libc.abilist      |   3 +
 sysdeps/unix/sysv/linux/arm/be/libc.abilist   |   3 +
 sysdeps/unix/sysv/linux/arm/le/libc.abilist   |   3 +
 sysdeps/unix/sysv/linux/csky/libc.abilist     |   3 +
 sysdeps/unix/sysv/linux/hppa/libc.abilist     |   3 +
 sysdeps/unix/sysv/linux/i386/libc.abilist     |   3 +
 sysdeps/unix/sysv/linux/ia64/libc.abilist     |   3 +
 .../sysv/linux/m68k/coldfire/libc.abilist     |   3 +
 .../unix/sysv/linux/m68k/m680x0/libc.abilist  |   3 +
 .../sysv/linux/microblaze/be/libc.abilist     |   3 +
 .../sysv/linux/microblaze/le/libc.abilist     |   3 +
 .../sysv/linux/mips/mips32/fpu/libc.abilist   |   3 +
 .../sysv/linux/mips/mips32/nofpu/libc.abilist |   3 +
 .../sysv/linux/mips/mips64/n32/libc.abilist   |   3 +
 .../sysv/linux/mips/mips64/n64/libc.abilist   |   3 +
 sysdeps/unix/sysv/linux/nios2/libc.abilist    |   3 +
 sysdeps/unix/sysv/linux/not-cancel.h          |   7 +
 sysdeps/unix/sysv/linux/or1k/libc.abilist     |   3 +
 .../linux/powerpc/powerpc32/fpu/libc.abilist  |   3 +
 .../powerpc/powerpc32/nofpu/libc.abilist      |   3 +
 .../linux/powerpc/powerpc64/be/libc.abilist   |   3 +
 .../linux/powerpc/powerpc64/le/libc.abilist   |   3 +
 .../unix/sysv/linux/riscv/rv32/libc.abilist   |   3 +
 .../unix/sysv/linux/riscv/rv64/libc.abilist   |   3 +
 .../unix/sysv/linux/s390/s390-32/libc.abilist |   3 +
 .../unix/sysv/linux/s390/s390-64/libc.abilist |   3 +
 sysdeps/unix/sysv/linux/sh/be/libc.abilist    |   3 +
 sysdeps/unix/sysv/linux/sh/le/libc.abilist    |   3 +
 .../sysv/linux/sparc/sparc32/libc.abilist     |   3 +
 .../sysv/linux/sparc/sparc64/libc.abilist     |   3 +
 sysdeps/unix/sysv/linux/tls-internal.c        |  39 +++-
 sysdeps/unix/sysv/linux/tls-internal.h        |   8 +-
 .../unix/sysv/linux/x86_64/64/libc.abilist    |   3 +
 .../unix/sysv/linux/x86_64/x32/libc.abilist   |   3 +
 55 files changed, 792 insertions(+), 15 deletions(-)
 create mode 100644 stdlib/arc4random.c
 create mode 100644 stdlib/arc4random.h
 create mode 100644 stdlib/arc4random_uniform.c
 create mode 100644 stdlib/chacha20.c

diff --git a/NEWS b/NEWS
index df882ec243..8420a65cd0 100644
--- a/NEWS
+++ b/NEWS
@@ -60,6 +60,10 @@ Major new features:
   _GNU_SOURCE macro is defined and the C++20 __cpp_char8_t feature test macro
   is not defined (if __cpp_char8_t is defined, then char8_t is a builtin type).
 
+* The functions arc4random, arc4random_buf, and arc4random_uniform have been
+  added.  The functions use a pseudo-random number generator along with
+  entropy from the kernel.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * Support for prelink will be removed in the next release; this includes
diff --git a/include/stdlib.h b/include/stdlib.h
index 1c6f70b082..cae7f7cdf8 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -144,6 +144,18 @@ libc_hidden_proto (__ptsname_r)
 libc_hidden_proto (grantpt)
 libc_hidden_proto (unlockpt)
 
+__typeof (arc4random) __arc4random;
+libc_hidden_proto (__arc4random);
+__typeof (arc4random_buf) __arc4random_buf;
+libc_hidden_proto (__arc4random_buf);
+__typeof (arc4random_uniform) __arc4random_uniform;
+libc_hidden_proto (__arc4random_uniform);
+extern void __arc4random_buf_internal (void *buffer, size_t len)
+     attribute_hidden;
+/* Called from the fork function to reinitialize the internal cipher state
+   in child process.  */
+extern void __arc4random_fork_subprocess (void) attribute_hidden;
+
 extern double __strtod_internal (const char *__restrict __nptr,
 				 char **__restrict __endptr, int __group)
      __THROW __nonnull ((1)) __wur;
diff --git a/malloc/thread-freeres.c b/malloc/thread-freeres.c
index 3894652169..b22e1d789f 100644
--- a/malloc/thread-freeres.c
+++ b/malloc/thread-freeres.c
@@ -36,7 +36,7 @@ __libc_thread_freeres (void)
   __rpc_thread_destroy ();
 #endif
   call_function_static_weak (__res_thread_freeres);
-  __glibc_tls_internal_free ();
+  call_function_static_weak (__glibc_tls_internal_free);
   call_function_static_weak (__libc_dlerror_result_free);
 
   /* This should come last because it shuts down malloc for this
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index 98f5f6dd85..219854f2cb 100644
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -32,6 +32,7 @@
 #include <kernel-features.h>
 #include <nptl-stack.h>
 #include <libc-lock.h>
+#include <tls-internal.h>
 
 /* Default alignment of stack.  */
 #ifndef STACK_ALIGN
@@ -127,7 +128,7 @@ get_cached_stack (size_t *sizep, void **memp)
 
   result->exiting = false;
   __libc_lock_init (result->exit_lock);
-  result->tls_state = (struct tls_internal_t) { 0 };
+  memset (&result->tls_state, 0, sizeof result->tls_state);
 
   /* Clear the DTV.  */
   dtv_t *dtv = GET_DTV (TLS_TPADJ (result));
diff --git a/stdlib/Makefile b/stdlib/Makefile
index d4a4d5679a..62f8253225 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -53,6 +53,8 @@ routines := \
   a64l \
   abort \
   abs \
+  arc4random \
+  arc4random_uniform \
   at_quick_exit \
   atof \
   atoi \
diff --git a/stdlib/Versions b/stdlib/Versions
index 5e9099a153..d09a308fb5 100644
--- a/stdlib/Versions
+++ b/stdlib/Versions
@@ -136,6 +136,11 @@ libc {
     strtof32; strtof64; strtof32x;
     strtof32_l; strtof64_l; strtof32x_l;
   }
+  GLIBC_2.36 {
+    arc4random;
+    arc4random_buf;
+    arc4random_uniform;
+  }
   GLIBC_PRIVATE {
     # functions which have an additional interface since they are
     # are cancelable.
diff --git a/stdlib/arc4random.c b/stdlib/arc4random.c
new file mode 100644
index 0000000000..d91f5466fb
--- /dev/null
+++ b/stdlib/arc4random.c
@@ -0,0 +1,208 @@
+/* Pseudo Random Number Generator based on ChaCha20.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <arc4random.h>
+#include <errno.h>
+#include <not-cancel.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+#include <sys/random.h>
+#include <tls-internal.h>
+
+/* arc4random keeps two counters: 'have' is the current valid bytes not yet
+   consumed in 'buf' while 'count' is the maximum number of bytes until a
+   reseed.
+
+   Both the initial seed and reseed try to obtain entropy from the kernel
+   and abort the process if none could be obtained.
+
+   The state 'buf' improves the usage of the cipher calls, allowing to call
+   optimized implementations (if the architecture provides it) and minimize
+   function call overhead.  */
+
+#include <chacha20.c>
+
+/* Called from the fork function to reset the state.  */
+void
+__arc4random_fork_subprocess (void)
+{
+  struct arc4random_state_t *state = __glibc_tls_internal ()->rand_state;
+  if (state != NULL)
+    {
+      explicit_bzero (state, sizeof (*state));
+      /* Force key init.  */
+      state->count = -1;
+    }
+}
+
+/* Return the current thread random state or try to create one if there is
+   none available.  In the case malloc can not allocate a state, arc4random
+   will try to get entropy with arc4random_getentropy.  */
+static struct arc4random_state_t *
+arc4random_get_state (void)
+{
+  struct arc4random_state_t *state = __glibc_tls_internal ()->rand_state;
+  if (state == NULL)
+    {
+      state = malloc (sizeof (struct arc4random_state_t));
+      if (state != NULL)
+	{
+	  /* Force key initialization on first call.  */
+	  state->count = -1;
+	  __glibc_tls_internal ()->rand_state = state;
+	}
+    }
+  return state;
+}
+
+static void
+arc4random_getrandom_failure (void)
+{
+  __libc_fatal ("Fatal glibc error: cannot get entropy for arc4random\n");
+}
+
+static void
+arc4random_rekey (struct arc4random_state_t *state, uint8_t *rnd, size_t rndlen)
+{
+  chacha20_crypt (state->ctx, state->buf, state->buf);
+
+  /* Mix optional user provided data.  */
+  if (rnd != NULL)
+    {
+      size_t m = MIN (rndlen, CHACHA20_KEY_SIZE + CHACHA20_IV_SIZE);
+      for (size_t i = 0; i < m; i++)
+	state->buf[i] ^= rnd[i];
+    }
+
+  /* Immediately reinit for backtracking resistance.  */
+  chacha20_init (state->ctx, state->buf, state->buf + CHACHA20_KEY_SIZE);
+  explicit_bzero (state->buf, CHACHA20_KEY_SIZE + CHACHA20_IV_SIZE);
+  state->have = sizeof (state->buf) - (CHACHA20_KEY_SIZE + CHACHA20_IV_SIZE);
+}
+
+static void
+arc4random_getentropy (void *rnd, size_t len)
+{
+  if (__getrandom_nocancel (rnd, len, GRND_NONBLOCK) == len)
+    return;
+
+  int fd = TEMP_FAILURE_RETRY (__open64_nocancel ("/dev/urandom",
+						  O_RDONLY | O_CLOEXEC));
+  if (fd != -1)
+    {
+      uint8_t *p = rnd;
+      uint8_t *end = p + len;
+      do
+	{
+	  ssize_t ret = TEMP_FAILURE_RETRY (__read_nocancel (fd, p, end - p));
+	  if (ret <= 0)
+	    arc4random_getrandom_failure ();
+	  p += ret;
+	}
+      while (p < end);
+
+      if (__close_nocancel (fd) == 0)
+	return;
+    }
+  arc4random_getrandom_failure ();
+}
+
+/* Check if the thread context STATE should be reseed with kernel entropy
+   depending of requested LEN bytes.  If there is less than requested,
+   the state is either initialized or reseeded, otherwise the internal
+   counter subtract the requested length.  */
+static void
+arc4random_check_stir (struct arc4random_state_t *state, size_t len)
+{
+  if (state->count <= len || state->count == -1)
+    {
+      uint8_t rnd[CHACHA20_KEY_SIZE + CHACHA20_IV_SIZE];
+      arc4random_getentropy (rnd, sizeof rnd);
+
+      if (state->count == -1)
+	chacha20_init (state->ctx, rnd, rnd + CHACHA20_KEY_SIZE);
+      else
+	arc4random_rekey (state, rnd, sizeof rnd);
+
+      explicit_bzero (rnd, sizeof rnd);
+
+      /* Invalidate the buf.  */
+      state->have = 0;
+      memset (state->buf, 0, sizeof state->buf);
+      state->count = CHACHA20_RESEED_SIZE;
+    }
+  else
+    state->count -= len;
+}
+
+void
+__arc4random_buf (void *buffer, size_t len)
+{
+  struct arc4random_state_t *state = arc4random_get_state ();
+  if (__glibc_unlikely (state == NULL))
+    {
+      arc4random_getentropy (buffer, len);
+      return;
+    }
+
+  arc4random_check_stir (state, len);
+  while (len > 0)
+    {
+      if (state->have > 0)
+	{
+	  size_t m = MIN (len, state->have);
+	  uint8_t *ks = state->buf + sizeof (state->buf) - state->have;
+	  memcpy (buffer, ks, m);
+	  explicit_bzero (ks, m);
+	  buffer += m;
+	  len -= m;
+	  state->have -= m;
+	}
+      if (state->have == 0)
+	arc4random_rekey (state, NULL, 0);
+    }
+}
+libc_hidden_def (__arc4random_buf)
+weak_alias (__arc4random_buf, arc4random_buf)
+
+uint32_t
+__arc4random (void)
+{
+  uint32_t r;
+
+  struct arc4random_state_t *state = arc4random_get_state ();
+  if (__glibc_unlikely (state == NULL))
+    {
+      arc4random_getentropy (&r, sizeof (uint32_t));
+      return r;
+    }
+
+  arc4random_check_stir (state, sizeof (uint32_t));
+  if (state->have < sizeof (uint32_t))
+    arc4random_rekey (state, NULL, 0);
+  uint8_t *ks = state->buf + sizeof (state->buf) - state->have;
+  memcpy (&r, ks, sizeof (uint32_t));
+  memset (ks, 0, sizeof (uint32_t));
+  state->have -= sizeof (uint32_t);
+
+  return r;
+}
+libc_hidden_def (__arc4random)
+weak_alias (__arc4random, arc4random)
diff --git a/stdlib/arc4random.h b/stdlib/arc4random.h
new file mode 100644
index 0000000000..cd39389c19
--- /dev/null
+++ b/stdlib/arc4random.h
@@ -0,0 +1,48 @@
+/* Arc4random definition used on TLS.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _CHACHA20_H
+#define _CHACHA20_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/* Internal ChaCha20 state.  */
+#define CHACHA20_STATE_LEN	16
+#define CHACHA20_BLOCK_SIZE	64
+
+/* Maximum number bytes until reseed (16 MB).  */
+#define CHACHA20_RESEED_SIZE	(16 * 1024 * 1024)
+
+/* Internal arc4random buffer, used on each feedback step so offer some
+   backtracking protection and to allow better used of vectorized
+   chacha20 implementations.  */
+#define CHACHA20_BUFSIZE        (8 * CHACHA20_BLOCK_SIZE)
+
+_Static_assert (CHACHA20_BUFSIZE >= CHACHA20_BLOCK_SIZE + CHACHA20_BLOCK_SIZE,
+		"CHACHA20_BUFSIZE < CHACHA20_BLOCK_SIZE + CHACHA20_BLOCK_SIZE");
+
+struct arc4random_state_t
+{
+  uint32_t ctx[CHACHA20_STATE_LEN];
+  size_t have;
+  size_t count;
+  uint8_t buf[CHACHA20_BUFSIZE];
+};
+
+#endif
diff --git a/stdlib/arc4random_uniform.c b/stdlib/arc4random_uniform.c
new file mode 100644
index 0000000000..1326dfa593
--- /dev/null
+++ b/stdlib/arc4random_uniform.c
@@ -0,0 +1,140 @@
+/* Random pseudo generator number which returns a single 32 bit value
+   uniformly distributed but with an upper_bound.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <endian.h>
+#include <libc-lock.h>
+#include <stdlib.h>
+#include <sys/param.h>
+
+/* Return the number of bytes which cover values up to the limit.  */
+__attribute__ ((const))
+static uint32_t
+byte_count (uint32_t n)
+{
+  if (n < (1U << 8))
+    return 1;
+  else if (n < (1U << 16))
+    return 2;
+  else if (n < (1U << 24))
+    return 3;
+  else
+    return 4;
+}
+
+/* Fill the lower bits of the result with randomness, according to the
+   number of bytes requested.  */
+static void
+random_bytes (uint32_t *result, uint32_t byte_count)
+{
+  *result = 0;
+  unsigned char *ptr = (unsigned char *) result;
+  if (__BYTE_ORDER == __BIG_ENDIAN)
+    ptr += 4 - byte_count;
+  __arc4random_buf (ptr, byte_count);
+}
+
+uint32_t
+__arc4random_uniform (uint32_t n)
+{
+  if (n <= 1)
+    /* There is no valid return value for a zero limit, and 0 is the
+       only possible result for limit 1.  */
+    return 0;
+
+  /* The bits variable serves as a source for bits.  Prefetch the
+     minimum number of bytes needed.  */
+  uint32_t count = byte_count (n);
+  uint32_t bits_length = count * CHAR_BIT;
+  uint32_t bits;
+  random_bytes (&bits, count);
+
+  /* Powers of two are easy.  */
+  if (powerof2 (n))
+    return bits & (n - 1);
+
+  /* The general case.  This algorithm follows Jérémie Lumbroso,
+     Optimal Discrete Uniform Generation from Coin Flips, and
+     Applications (2013), who credits Donald E. Knuth and Andrew
+     C. Yao, The complexity of nonuniform random number generation
+     (1976), for solving the general case.
+
+     The implementation below unrolls the initialization stage of the
+     loop, where v is less than n.  */
+
+  /* Use 64-bit variables even though the intermediate results are
+     never larger than 33 bits.  This ensures the code is easier to
+     compile on 64-bit architectures.  */
+  uint64_t v;
+  uint64_t c;
+
+  /* Initialize v and c.  v is the smallest power of 2 which is larger
+     than n.*/
+  {
+    uint32_t log2p1 = 32 - __builtin_clz (n);
+    v = 1ULL << log2p1;
+    c = bits & (v - 1);
+    bits >>= log2p1;
+    bits_length -= log2p1;
+  }
+
+  /* At the start of the loop, c is uniformly distributed within the
+     half-open interval [0, v), and v < 2n < 2**33.  */
+  while (true)
+    {
+      if (v >= n)
+        {
+          /* If the candidate is less than n, accept it.  */
+          if (c < n)
+            /* c is uniformly distributed on [0, n).  */
+            return c;
+          else
+            {
+              /* c is uniformly distributed on [n, v).  */
+              v -= n;
+              c -= n;
+              /* The distribution was shifted, so c is uniformly
+                 distributed on [0, v) again.  */
+            }
+        }
+      /* v < n here.  */
+
+      /* Replenish the bit source if necessary.  */
+      if (bits_length == 0)
+        {
+          /* Overwrite the least significant byte.  */
+	  random_bytes (&bits, 1);
+	  bits_length = CHAR_BIT;
+        }
+
+      /* Double the range.  No overflow because v < n < 2**32.  */
+      v *= 2;
+      /* v < 2n here.  */
+
+      /* Extract a bit and append it to c.  c remains less than v and
+         thus 2**33.  */
+      c = (c << 1) | (bits & 1);
+      bits >>= 1;
+      --bits_length;
+
+      /* At this point, c is uniformly distributed on [0, v) again,
+         and v < 2n < 2**33.  */
+    }
+}
+libc_hidden_def (__arc4random_uniform)
+weak_alias (__arc4random_uniform, arc4random_uniform)
diff --git a/stdlib/chacha20.c b/stdlib/chacha20.c
new file mode 100644
index 0000000000..77e37655cd
--- /dev/null
+++ b/stdlib/chacha20.c
@@ -0,0 +1,179 @@
+/* Generic ChaCha20 implementation (used on arc4random).
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <array_length.h>
+#include <endian.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+/* 32-bit stream position, then 96-bit nonce.  */
+#define CHACHA20_IV_SIZE	16
+#define CHACHA20_KEY_SIZE	32
+
+#define CHACHA20_STATE_LEN	16
+
+/* The ChaCha20 implementation is based on RFC8439 [1], omitting the final
+   XOR of the keystream with the plaintext because the plaintext is a
+   stream of zeros.  */
+
+enum chacha20_constants
+{
+  CHACHA20_CONSTANT_EXPA = 0x61707865U,
+  CHACHA20_CONSTANT_ND_3 = 0x3320646eU,
+  CHACHA20_CONSTANT_2_BY = 0x79622d32U,
+  CHACHA20_CONSTANT_TE_K = 0x6b206574U
+};
+
+static inline uint32_t
+read_unaligned_32 (const uint8_t *p)
+{
+  uint32_t r;
+  memcpy (&r, p, sizeof (r));
+  return r;
+}
+
+static inline void
+write_unaligned_32 (uint8_t *p, uint32_t v)
+{
+  memcpy (p, &v, sizeof (v));
+}
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+# define read_unaligned_le32(p) __builtin_bswap32 (read_unaligned_32 (p))
+# define set_state(v)		__builtin_bswap32 ((v))
+#else
+# define read_unaligned_le32(p) read_unaligned_32 ((p))
+# define set_state(v)		(v)
+#endif
+
+static inline void
+chacha20_init (uint32_t *state, const uint8_t *key, const uint8_t *iv)
+{
+  state[0]  = CHACHA20_CONSTANT_EXPA;
+  state[1]  = CHACHA20_CONSTANT_ND_3;
+  state[2]  = CHACHA20_CONSTANT_2_BY;
+  state[3]  = CHACHA20_CONSTANT_TE_K;
+
+  state[4]  = read_unaligned_le32 (key + 0 * sizeof (uint32_t));
+  state[5]  = read_unaligned_le32 (key + 1 * sizeof (uint32_t));
+  state[6]  = read_unaligned_le32 (key + 2 * sizeof (uint32_t));
+  state[7]  = read_unaligned_le32 (key + 3 * sizeof (uint32_t));
+  state[8]  = read_unaligned_le32 (key + 4 * sizeof (uint32_t));
+  state[9]  = read_unaligned_le32 (key + 5 * sizeof (uint32_t));
+  state[10] = read_unaligned_le32 (key + 6 * sizeof (uint32_t));
+  state[11] = read_unaligned_le32 (key + 7 * sizeof (uint32_t));
+
+  state[12] = read_unaligned_le32 (iv + 0 * sizeof (uint32_t));
+  state[13] = read_unaligned_le32 (iv + 1 * sizeof (uint32_t));
+  state[14] = read_unaligned_le32 (iv + 2 * sizeof (uint32_t));
+  state[15] = read_unaligned_le32 (iv + 3 * sizeof (uint32_t));
+}
+
+static inline uint32_t
+rotl32 (unsigned int shift, uint32_t word)
+{
+  return (word << (shift & 31)) | (word >> ((-shift) & 31));
+}
+
+static void
+state_final (const uint8_t *src, uint8_t *dst, uint32_t v)
+{
+#ifdef CHACHA20_XOR_FINAL
+  v ^= read_unaligned_32 (src);
+#endif
+  write_unaligned_32 (dst, v);
+}
+
+static inline void
+chacha20_block (uint32_t *state, uint8_t *dst, const uint8_t *src)
+{
+  uint32_t x0, x1, x2, x3, x4, x5, x6, x7;
+  uint32_t x8, x9, x10, x11, x12, x13, x14, x15;
+
+  x0 = state[0];
+  x1 = state[1];
+  x2 = state[2];
+  x3 = state[3];
+  x4 = state[4];
+  x5 = state[5];
+  x6 = state[6];
+  x7 = state[7];
+  x8 = state[8];
+  x9 = state[9];
+  x10 = state[10];
+  x11 = state[11];
+  x12 = state[12];
+  x13 = state[13];
+  x14 = state[14];
+  x15 = state[15];
+
+  for (int i = 0; i < 20; i += 2)
+    {
+#define QROUND(_x0, _x1, _x2, _x3) 			\
+  do {							\
+   _x0 = _x0 + _x1; _x3 = rotl32 (16, (_x0 ^ _x3)); 	\
+   _x2 = _x2 + _x3; _x1 = rotl32 (12, (_x1 ^ _x2)); 	\
+   _x0 = _x0 + _x1; _x3 = rotl32 (8,  (_x0 ^ _x3));	\
+   _x2 = _x2 + _x3; _x1 = rotl32 (7,  (_x1 ^ _x2));	\
+  } while(0)
+
+      QROUND (x0, x4, x8,  x12);
+      QROUND (x1, x5, x9,  x13);
+      QROUND (x2, x6, x10, x14);
+      QROUND (x3, x7, x11, x15);
+
+      QROUND (x0, x5, x10, x15);
+      QROUND (x1, x6, x11, x12);
+      QROUND (x2, x7, x8,  x13);
+      QROUND (x3, x4, x9,  x14);
+    }
+
+  state_final (&src[0], &dst[0], set_state (x0 + state[0]));
+  state_final (&src[4], &dst[4], set_state (x1 + state[1]));
+  state_final (&src[8], &dst[8], set_state (x2 + state[2]));
+  state_final (&src[12], &dst[12], set_state (x3 + state[3]));
+  state_final (&src[16], &dst[16], set_state (x4 + state[4]));
+  state_final (&src[20], &dst[20], set_state (x5 + state[5]));
+  state_final (&src[24], &dst[24], set_state (x6 + state[6]));
+  state_final (&src[28], &dst[28], set_state (x7 + state[7]));
+  state_final (&src[32], &dst[32], set_state (x8 + state[8]));
+  state_final (&src[36], &dst[36], set_state (x9 + state[9]));
+  state_final (&src[40], &dst[40], set_state (x10 + state[10]));
+  state_final (&src[44], &dst[44], set_state (x11 + state[11]));
+  state_final (&src[48], &dst[48], set_state (x12 + state[12]));
+  state_final (&src[52], &dst[52], set_state (x13 + state[13]));
+  state_final (&src[56], &dst[56], set_state (x14 + state[14]));
+  state_final (&src[60], &dst[60], set_state (x15 + state[15]));
+
+  state[12]++;
+}
+
+static void
+chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
+{
+  size_t bytes = CHACHA20_BUFSIZE;
+  while (bytes >= CHACHA20_BLOCK_SIZE)
+    {
+      chacha20_block (state, dst, src);
+
+      bytes -= CHACHA20_BLOCK_SIZE;
+      dst += CHACHA20_BLOCK_SIZE;
+      src += CHACHA20_BLOCK_SIZE;
+    }
+}
diff --git a/stdlib/stdlib.h b/stdlib/stdlib.h
index bf7cd438e1..3a630a0ce8 100644
--- a/stdlib/stdlib.h
+++ b/stdlib/stdlib.h
@@ -533,6 +533,19 @@ extern int seed48_r (unsigned short int __seed16v[3],
 extern int lcong48_r (unsigned short int __param[7],
 		      struct drand48_data *__buffer)
      __THROW __nonnull ((1, 2));
+
+/* Return a random integer between zero and 2**32-1 (inclusive).  */
+extern __uint32_t arc4random (void)
+     __THROW __wur;
+
+/* Fill the buffer with random data.  */
+extern void arc4random_buf (void *__buf, size_t __size)
+     __THROW __nonnull ((1));
+
+/* Return a random number between zero (inclusive) and the specified
+   limit (exclusive).  */
+extern __uint32_t arc4random_uniform (__uint32_t __upper_bound)
+     __THROW __wur;
 # endif	/* Use misc.  */
 #endif	/* Use misc or X/Open.  */
 
diff --git a/sysdeps/generic/not-cancel.h b/sysdeps/generic/not-cancel.h
index 2104efeb54..acceb9b67f 100644
--- a/sysdeps/generic/not-cancel.h
+++ b/sysdeps/generic/not-cancel.h
@@ -48,5 +48,7 @@
   (void) __writev (fd, iov, n)
 #define __fcntl64_nocancel(fd, cmd, ...) \
   __fcntl64 (fd, cmd, __VA_ARGS__)
+#define __getrandom_nocancel(buf, size, flags) \
+  __getrandom (buf, size, flags)
 
 #endif /* NOT_CANCEL_H  */
diff --git a/sysdeps/generic/tls-internal-struct.h b/sysdeps/generic/tls-internal-struct.h
index d76c715a96..a91915831b 100644
--- a/sysdeps/generic/tls-internal-struct.h
+++ b/sysdeps/generic/tls-internal-struct.h
@@ -23,6 +23,7 @@ struct tls_internal_t
 {
   char *strsignal_buf;
   char *strerror_l_buf;
+  struct arc4random_state_t *rand_state;
 };
 
 #endif
diff --git a/sysdeps/generic/tls-internal.c b/sysdeps/generic/tls-internal.c
index 898c20b61c..8a0f37d509 100644
--- a/sysdeps/generic/tls-internal.c
+++ b/sysdeps/generic/tls-internal.c
@@ -16,6 +16,24 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <stdlib/arc4random.h>
+#include <string.h>
 #include <tls-internal.h>
 
 __thread struct tls_internal_t __tls_internal;
+
+void
+__glibc_tls_internal_free (void)
+{
+  free (__tls_internal.strsignal_buf);
+  free (__tls_internal.strerror_l_buf);
+
+  if (__tls_internal.rand_state != NULL)
+    {
+      /* Clear any lingering random state prior so if the thread stack is
+	 cached it won't leak any data.  */
+      explicit_bzero (__tls_internal.rand_state,
+		      sizeof (*__tls_internal.rand_state));
+      free (__tls_internal.rand_state);
+    }
+}
diff --git a/sysdeps/generic/tls-internal.h b/sysdeps/generic/tls-internal.h
index acb8ac9abe..3f53e4a1fa 100644
--- a/sysdeps/generic/tls-internal.h
+++ b/sysdeps/generic/tls-internal.h
@@ -30,11 +30,6 @@ __glibc_tls_internal (void)
   return &__tls_internal;
 }
 
-static inline void
-__glibc_tls_internal_free (void)
-{
-  free (__tls_internal.strsignal_buf);
-  free (__tls_internal.strerror_l_buf);
-}
+extern void __glibc_tls_internal_free (void) attribute_hidden;
 
 #endif
diff --git a/sysdeps/mach/hurd/_Fork.c b/sysdeps/mach/hurd/_Fork.c
index e60b86fab1..667068c8cf 100644
--- a/sysdeps/mach/hurd/_Fork.c
+++ b/sysdeps/mach/hurd/_Fork.c
@@ -662,6 +662,8 @@ retry:
       _hurd_malloc_fork_child ();
       call_function_static_weak (__malloc_fork_unlock_child);
 
+      call_function_static_weak (__arc4random_fork_subprocess);
+
       /* Run things that want to run in the child task to set up.  */
       RUN_HOOK (_hurd_fork_child_hook, ());
 
diff --git a/sysdeps/mach/hurd/i386/libc.abilist b/sysdeps/mach/hurd/i386/libc.abilist
index 66fb0e28fa..4e3200ef55 100644
--- a/sysdeps/mach/hurd/i386/libc.abilist
+++ b/sysdeps/mach/hurd/i386/libc.abilist
@@ -2289,6 +2289,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 close_range F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 mbrtoc8 F
 GLIBC_2.4 __confstr_chk F
diff --git a/sysdeps/mach/hurd/not-cancel.h b/sysdeps/mach/hurd/not-cancel.h
index 6ec92ced84..9a3a7ed59a 100644
--- a/sysdeps/mach/hurd/not-cancel.h
+++ b/sysdeps/mach/hurd/not-cancel.h
@@ -74,6 +74,9 @@ __typeof (__fcntl) __fcntl_nocancel;
 #define __fcntl64_nocancel(...) \
   __fcntl_nocancel (__VA_ARGS__)
 
+#define __getrandom_nocancel(buf, size, flags) \
+  __getrandom (buf, size, flags)
+
 #if IS_IN (libc)
 hidden_proto (__close_nocancel)
 hidden_proto (__close_nocancel_nostatus)
diff --git a/sysdeps/nptl/_Fork.c b/sysdeps/nptl/_Fork.c
index dd568992e2..7dc02569f6 100644
--- a/sysdeps/nptl/_Fork.c
+++ b/sysdeps/nptl/_Fork.c
@@ -43,6 +43,8 @@ _Fork (void)
       self->robust_head.list = &self->robust_head;
       INTERNAL_SYSCALL_CALL (set_robust_list, &self->robust_head,
 			     sizeof (struct robust_list_head));
+
+      call_function_static_weak (__arc4random_fork_subprocess);
     }
   return pid;
 }
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 516b029d30..b66fadef40 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2616,6 +2616,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index dde08899fe..f918bb2d48 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2713,6 +2713,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/arc/libc.abilist b/sysdeps/unix/sysv/linux/arc/libc.abilist
index ade44d3029..093043a533 100644
--- a/sysdeps/unix/sysv/linux/arc/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
@@ -2377,6 +2377,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
index 98b33708af..e0668a80cf 100644
--- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
@@ -496,6 +496,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/arm/le/libc.abilist b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
index 05dbbe5bcc..d28e7c60b7 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -493,6 +493,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/csky/libc.abilist b/sysdeps/unix/sysv/linux/csky/libc.abilist
index 430a24349e..922b05062f 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2652,6 +2652,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index de44616526..412144f94c 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2601,6 +2601,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 18b4fbf26e..134393900a 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2785,6 +2785,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index a8e959d417..02c65b6482 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -2551,6 +2551,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 3a7e4ef6e4..0604029c68 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -497,6 +497,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 864ad2cdf8..af2be5c80d 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2728,6 +2728,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
index 163058420d..e090b8d48f 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2701,6 +2701,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
index a6debfda56..8c5b2db243 100644
--- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
@@ -2698,6 +2698,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 2b53d888de..68847134a2 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2693,6 +2693,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index 849aae4130..daa44e64fa 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -2691,6 +2691,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index 37f6c1bf58..6169188c96 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2699,6 +2699,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index ff1eb91e10..2f7f1ccaf7 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2602,6 +2602,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 361b91f547..58e9b486b0 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2740,6 +2740,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/not-cancel.h b/sysdeps/unix/sysv/linux/not-cancel.h
index 75b9e0ee1e..2c58d5ae2f 100644
--- a/sysdeps/unix/sysv/linux/not-cancel.h
+++ b/sysdeps/unix/sysv/linux/not-cancel.h
@@ -67,6 +67,13 @@ __writev_nocancel_nostatus (int fd, const struct iovec *iov, int iovcnt)
   INTERNAL_SYSCALL_CALL (writev, fd, iov, iovcnt);
 }
 
+static inline int
+__getrandom_nocancel (void *buf, size_t buflen, unsigned int flags)
+{
+  return INTERNAL_SYSCALL_CALL (getrandom, buf, buflen, flags);
+}
+
+
 /* Uncancelable fcntl.  */
 __typeof (__fcntl) __fcntl64_nocancel;
 
diff --git a/sysdeps/unix/sysv/linux/or1k/libc.abilist b/sysdeps/unix/sysv/linux/or1k/libc.abilist
index cb91606377..ffdb8819d5 100644
--- a/sysdeps/unix/sysv/linux/or1k/libc.abilist
+++ b/sysdeps/unix/sysv/linux/or1k/libc.abilist
@@ -2123,6 +2123,9 @@ GLIBC_2.35 wprintf F
 GLIBC_2.35 write F
 GLIBC_2.35 writev F
 GLIBC_2.35 wscanf F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 1264aff6ef..8c9ca32cbe 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -2755,6 +2755,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index f96d6e37b5..08a6604aab 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -2788,6 +2788,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
index e7082e1bd3..849863e639 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2510,6 +2510,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
index 1032c7e46a..b2ccee08c6 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2812,6 +2812,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index f932db7c22..ff90d1bff2 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2379,6 +2379,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index ccc53b0bb8..f1017f6ec5 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2579,6 +2579,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index dbf6501007..009f22931e 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2753,6 +2753,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index 98f08a01b6..0e0b3df973 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2547,6 +2547,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/sh/be/libc.abilist b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
index df11cc8f13..afb5bc37b1 100644
--- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
@@ -2608,6 +2608,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/sh/le/libc.abilist b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
index 4ee5513d18..2b53a3cf92 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2605,6 +2605,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 3cefa76871..43b9844a99 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -2748,6 +2748,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index e3ea5c4383..9ec4a0bc7f 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2574,6 +2574,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/tls-internal.c b/sysdeps/unix/sysv/linux/tls-internal.c
index 6e25b021ab..0326ebb767 100644
--- a/sysdeps/unix/sysv/linux/tls-internal.c
+++ b/sysdeps/unix/sysv/linux/tls-internal.c
@@ -1 +1,38 @@
-/* Empty.  */
+/* Per-thread state.  Linux version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <stdlib/arc4random.h>
+#include <string.h>
+#include <tls-internal.h>
+
+void
+__glibc_tls_internal_free (void)
+{
+  struct pthread *self = THREAD_SELF;
+  free (self->tls_state.strsignal_buf);
+  free (self->tls_state.strerror_l_buf);
+
+  if (self->tls_state.rand_state != NULL)
+    {
+      /* Clear any lingering random state prior so if the thread stack is
+         cached it won't leak any data.  */
+      explicit_bzero (self->tls_state.rand_state,
+		      sizeof (*self->tls_state.rand_state));
+      free (self->tls_state.rand_state);
+    }
+}
diff --git a/sysdeps/unix/sysv/linux/tls-internal.h b/sysdeps/unix/sysv/linux/tls-internal.h
index f7a1a62135..ebc65d896a 100644
--- a/sysdeps/unix/sysv/linux/tls-internal.h
+++ b/sysdeps/unix/sysv/linux/tls-internal.h
@@ -28,11 +28,7 @@ __glibc_tls_internal (void)
   return &THREAD_SELF->tls_state;
 }
 
-static inline void
-__glibc_tls_internal_free (void)
-{
-  free (THREAD_SELF->tls_state.strsignal_buf);
-  free (THREAD_SELF->tls_state.strerror_l_buf);
-}
+/* Reset the arc4random TCB state on fork.  */
+extern void __glibc_tls_internal_free (void) attribute_hidden;
 
 #endif
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index 2944bc7837..367c8d0a03 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2525,6 +2525,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 47296193af..6a614efb62 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2631,6 +2631,9 @@ GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
 GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
+GLIBC_2.36 arc4random F
+GLIBC_2.36 arc4random_buf F
+GLIBC_2.36 arc4random_uniform F
 GLIBC_2.36 c8rtomb F
 GLIBC_2.36 fsconfig F
 GLIBC_2.36 fsmount F
-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH v12 2/9] stdlib: Add arc4random tests
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417) Adhemerval Zanella
@ 2022-07-22 12:21 ` Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 3/9] benchtests: Add arc4random benchtest Adhemerval Zanella
                   ` (7 subsequent siblings)
  9 siblings, 0 replies; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

The basic tst-arc4random-chacha20.c checks if the output of ChaCha20
implementation matches the reference test vectors from RFC8439.

The tst-arc4random-fork.c check if subprocesses generate distinct
streams of randomness (if fork handling is done correctly).

The tst-arc4random-stats.c is a statistical test to the randomness of
arc4random, arc4random_buf, and arc4random_uniform.

The tst-arc4random-thread.c check if threads generate distinct streams
of randomness (if function are thread-safe).

Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu.

Co-authored-by: Florian Weimer <fweimer@redhat.com>

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
---
 stdlib/Makefile                  |   7 +
 stdlib/tst-arc4random-chacha20.c | 167 +++++++++++++++
 stdlib/tst-arc4random-fork.c     | 198 ++++++++++++++++++
 stdlib/tst-arc4random-stats.c    | 147 +++++++++++++
 stdlib/tst-arc4random-thread.c   | 341 +++++++++++++++++++++++++++++++
 5 files changed, 860 insertions(+)
 create mode 100644 stdlib/tst-arc4random-chacha20.c
 create mode 100644 stdlib/tst-arc4random-fork.c
 create mode 100644 stdlib/tst-arc4random-stats.c
 create mode 100644 stdlib/tst-arc4random-thread.c

diff --git a/stdlib/Makefile b/stdlib/Makefile
index 62f8253225..a900962685 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -183,6 +183,9 @@ tests := \
   testmb2 \
   testrand \
   testsort \
+  tst-arc4random-fork \
+  tst-arc4random-stats \
+  tst-arc4random-thread \
   tst-at_quick_exit \
   tst-atexit \
   tst-atof1 \
@@ -243,6 +246,7 @@ tests := \
   # tests
 
 tests-internal := \
+  tst-arc4random-chacha20 \
   tst-strtod1i \
   tst-strtod3 \
   tst-strtod4 \
@@ -252,6 +256,7 @@ tests-internal := \
   # tests-internal
 
 tests-static := \
+  tst-arc4random-chacha20 \
   tst-secure-getenv \
   # tests-static
 
@@ -271,6 +276,8 @@ LDLIBS-test-cxa_atexit-race = $(shared-thread-library)
 LDLIBS-test-cxa_atexit-race2 = $(shared-thread-library)
 LDLIBS-test-on_exit-race = $(shared-thread-library)
 LDLIBS-tst-canon-bz26341 = $(shared-thread-library)
+LDLIBS-tst-arc4random-fork = $(shared-thread-library)
+LDLIBS-tst-arc4random-thread = $(shared-thread-library)
 
 LDLIBS-test-dlclose-exit-race = $(shared-thread-library)
 LDFLAGS-test-dlclose-exit-race = $(LDFLAGS-rdynamic)
diff --git a/stdlib/tst-arc4random-chacha20.c b/stdlib/tst-arc4random-chacha20.c
new file mode 100644
index 0000000000..900ab6ae0a
--- /dev/null
+++ b/stdlib/tst-arc4random-chacha20.c
@@ -0,0 +1,167 @@
+/* Basic tests for chacha20 cypher used in arc4random.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <arc4random.h>
+#include <support/check.h>
+#include <sys/cdefs.h>
+
+/* The test does not define CHACHA20_XOR_FINAL to mimic what arc4random
+   actual does.  */
+#include <chacha20.c>
+
+static int
+do_test (void)
+{
+  const uint8_t key[CHACHA20_KEY_SIZE] =
+    {
+      0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+      0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+      0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+      0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+    };
+  const uint8_t iv[CHACHA20_IV_SIZE] =
+    {
+      0x0, 0x0, 0x0, 0x0,
+      0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+    };
+  const uint8_t expected1[CHACHA20_BUFSIZE] =
+    {
+      0x76, 0xb8, 0xe0, 0xad, 0xa0, 0xf1, 0x3d, 0x90, 0x40, 0x5d, 0x6a,
+      0xe5, 0x53, 0x86, 0xbd, 0x28, 0xbd, 0xd2, 0x19, 0xb8, 0xa0, 0x8d,
+      0xed, 0x1a, 0xa8, 0x36, 0xef, 0xcc, 0x8b, 0x77, 0x0d, 0xc7, 0xda,
+      0x41, 0x59, 0x7c, 0x51, 0x57, 0x48, 0x8d, 0x77, 0x24, 0xe0, 0x3f,
+      0xb8, 0xd8, 0x4a, 0x37, 0x6a, 0x43, 0xb8, 0xf4, 0x15, 0x18, 0xa1,
+      0x1c, 0xc3, 0x87, 0xb6, 0x69, 0xb2, 0xee, 0x65, 0x86, 0x9f, 0x07,
+      0xe7, 0xbe, 0x55, 0x51, 0x38, 0x7a, 0x98, 0xba, 0x97, 0x7c, 0x73,
+      0x2d, 0x08, 0x0d, 0xcb, 0x0f, 0x29, 0xa0, 0x48, 0xe3, 0x65, 0x69,
+      0x12, 0xc6, 0x53, 0x3e, 0x32, 0xee, 0x7a, 0xed, 0x29, 0xb7, 0x21,
+      0x76, 0x9c, 0xe6, 0x4e, 0x43, 0xd5, 0x71, 0x33, 0xb0, 0x74, 0xd8,
+      0x39, 0xd5, 0x31, 0xed, 0x1f, 0x28, 0x51, 0x0a, 0xfb, 0x45, 0xac,
+      0xe1, 0x0a, 0x1f, 0x4b, 0x79, 0x4d, 0x6f, 0x2d, 0x09, 0xa0, 0xe6,
+      0x63, 0x26, 0x6c, 0xe1, 0xae, 0x7e, 0xd1, 0x08, 0x19, 0x68, 0xa0,
+      0x75, 0x8e, 0x71, 0x8e, 0x99, 0x7b, 0xd3, 0x62, 0xc6, 0xb0, 0xc3,
+      0x46, 0x34, 0xa9, 0xa0, 0xb3, 0x5d, 0x01, 0x27, 0x37, 0x68, 0x1f,
+      0x7b, 0x5d, 0x0f, 0x28, 0x1e, 0x3a, 0xfd, 0xe4, 0x58, 0xbc, 0x1e,
+      0x73, 0xd2, 0xd3, 0x13, 0xc9, 0xcf, 0x94, 0xc0, 0x5f, 0xf3, 0x71,
+      0x62, 0x40, 0xa2, 0x48, 0xf2, 0x13, 0x20, 0xa0, 0x58, 0xd7, 0xb3,
+      0x56, 0x6b, 0xd5, 0x20, 0xda, 0xaa, 0x3e, 0xd2, 0xbf, 0x0a, 0xc5,
+      0xb8, 0xb1, 0x20, 0xfb, 0x85, 0x27, 0x73, 0xc3, 0x63, 0x97, 0x34,
+      0xb4, 0x5c, 0x91, 0xa4, 0x2d, 0xd4, 0xcb, 0x83, 0xf8, 0x84, 0x0d,
+      0x2e, 0xed, 0xb1, 0x58, 0x13, 0x10, 0x62, 0xac, 0x3f, 0x1f, 0x2c,
+      0xf8, 0xff, 0x6d, 0xcd, 0x18, 0x56, 0xe8, 0x6a, 0x1e, 0x6c, 0x31,
+      0x67, 0x16, 0x7e, 0xe5, 0xa6, 0x88, 0x74, 0x2b, 0x47, 0xc5, 0xad,
+      0xfb, 0x59, 0xd4, 0xdf, 0x76, 0xfd, 0x1d, 0xb1, 0xe5, 0x1e, 0xe0,
+      0x3b, 0x1c, 0xa9, 0xf8, 0x2a, 0xca, 0x17, 0x3e, 0xdb, 0x8b, 0x72,
+      0x93, 0x47, 0x4e, 0xbe, 0x98, 0x0f, 0x90, 0x4d, 0x10, 0xc9, 0x16,
+      0x44, 0x2b, 0x47, 0x83, 0xa0, 0xe9, 0x84, 0x86, 0x0c, 0xb6, 0xc9,
+      0x57, 0xb3, 0x9c, 0x38, 0xed, 0x8f, 0x51, 0xcf, 0xfa, 0xa6, 0x8a,
+      0x4d, 0xe0, 0x10, 0x25, 0xa3, 0x9c, 0x50, 0x45, 0x46, 0xb9, 0xdc,
+      0x14, 0x06, 0xa7, 0xeb, 0x28, 0x15, 0x1e, 0x51, 0x50, 0xd7, 0xb2,
+      0x04, 0xba, 0xa7, 0x19, 0xd4, 0xf0, 0x91, 0x02, 0x12, 0x17, 0xdb,
+      0x5c, 0xf1, 0xb5, 0xc8, 0x4c, 0x4f, 0xa7, 0x1a, 0x87, 0x96, 0x10,
+      0xa1, 0xa6, 0x95, 0xac, 0x52, 0x7c, 0x5b, 0x56, 0x77, 0x4a, 0x6b,
+      0x8a, 0x21, 0xaa, 0xe8, 0x86, 0x85, 0x86, 0x8e, 0x09, 0x4c, 0xf2,
+      0x9e, 0xf4, 0x09, 0x0a, 0xf7, 0xa9, 0x0c, 0xc0, 0x7e, 0x88, 0x17,
+      0xaa, 0x52, 0x87, 0x63, 0x79, 0x7d, 0x3c, 0x33, 0x2b, 0x67, 0xca,
+      0x4b, 0xc1, 0x10, 0x64, 0x2c, 0x21, 0x51, 0xec, 0x47, 0xee, 0x84,
+      0xcb, 0x8c, 0x42, 0xd8, 0x5f, 0x10, 0xe2, 0xa8, 0xcb, 0x18, 0xc3,
+      0xb7, 0x33, 0x5f, 0x26, 0xe8, 0xc3, 0x9a, 0x12, 0xb1, 0xbc, 0xc1,
+      0x70, 0x71, 0x77, 0xb7, 0x61, 0x38, 0x73, 0x2e, 0xed, 0xaa, 0xb7,
+      0x4d, 0xa1, 0x41, 0x0f, 0xc0, 0x55, 0xea, 0x06, 0x8c, 0x99, 0xe9,
+      0x26, 0x0a, 0xcb, 0xe3, 0x37, 0xcf, 0x5d, 0x3e, 0x00, 0xe5, 0xb3,
+      0x23, 0x0f, 0xfe, 0xdb, 0x0b, 0x99, 0x07, 0x87, 0xd0, 0xc7, 0x0e,
+      0x0b, 0xfe, 0x41, 0x98, 0xea, 0x67, 0x58, 0xdd, 0x5a, 0x61, 0xfb,
+      0x5f, 0xec, 0x2d, 0xf9, 0x81, 0xf3, 0x1b, 0xef, 0xe1, 0x53, 0xf8,
+      0x1d, 0x17, 0x16, 0x17, 0x84, 0xdb
+    };
+
+  const uint8_t expected2[CHACHA20_BUFSIZE] =
+    {
+      0x1c, 0x88, 0x22, 0xd5, 0x3c, 0xd1, 0xee, 0x7d, 0xb5, 0x32, 0x36,
+      0x48, 0x28, 0xbd, 0xf4, 0x04, 0xb0, 0x40, 0xa8, 0xdc, 0xc5, 0x22,
+      0xf3, 0xd3, 0xd9, 0x9a, 0xec, 0x4b, 0x80, 0x57, 0xed, 0xb8, 0x50,
+      0x09, 0x31, 0xa2, 0xc4, 0x2d, 0x2f, 0x0c, 0x57, 0x08, 0x47, 0x10,
+      0x0b, 0x57, 0x54, 0xda, 0xfc, 0x5f, 0xbd, 0xb8, 0x94, 0xbb, 0xef,
+      0x1a, 0x2d, 0xe1, 0xa0, 0x7f, 0x8b, 0xa0, 0xc4, 0xb9, 0x19, 0x30,
+      0x10, 0x66, 0xed, 0xbc, 0x05, 0x6b, 0x7b, 0x48, 0x1e, 0x7a, 0x0c,
+      0x46, 0x29, 0x7b, 0xbb, 0x58, 0x9d, 0x9d, 0xa5, 0xb6, 0x75, 0xa6,
+      0x72, 0x3e, 0x15, 0x2e, 0x5e, 0x63, 0xa4, 0xce, 0x03, 0x4e, 0x9e,
+      0x83, 0xe5, 0x8a, 0x01, 0x3a, 0xf0, 0xe7, 0x35, 0x2f, 0xb7, 0x90,
+      0x85, 0x14, 0xe3, 0xb3, 0xd1, 0x04, 0x0d, 0x0b, 0xb9, 0x63, 0xb3,
+      0x95, 0x4b, 0x63, 0x6b, 0x5f, 0xd4, 0xbf, 0x6d, 0x0a, 0xad, 0xba,
+      0xf8, 0x15, 0x7d, 0x06, 0x2a, 0xcb, 0x24, 0x18, 0xc1, 0x76, 0xa4,
+      0x75, 0x51, 0x1b, 0x35, 0xc3, 0xf6, 0x21, 0x8a, 0x56, 0x68, 0xea,
+      0x5b, 0xc6, 0xf5, 0x4b, 0x87, 0x82, 0xf8, 0xb3, 0x40, 0xf0, 0x0a,
+      0xc1, 0xbe, 0xba, 0x5e, 0x62, 0xcd, 0x63, 0x2a, 0x7c, 0xe7, 0x80,
+      0x9c, 0x72, 0x56, 0x08, 0xac, 0xa5, 0xef, 0xbf, 0x7c, 0x41, 0xf2,
+      0x37, 0x64, 0x3f, 0x06, 0xc0, 0x99, 0x72, 0x07, 0x17, 0x1d, 0xe8,
+      0x67, 0xf9, 0xd6, 0x97, 0xbf, 0x5e, 0xa6, 0x01, 0x1a, 0xbc, 0xce,
+      0x6c, 0x8c, 0xdb, 0x21, 0x13, 0x94, 0xd2, 0xc0, 0x2d, 0xd0, 0xfb,
+      0x60, 0xdb, 0x5a, 0x2c, 0x17, 0xac, 0x3d, 0xc8, 0x58, 0x78, 0xa9,
+      0x0b, 0xed, 0x38, 0x09, 0xdb, 0xb9, 0x6e, 0xaa, 0x54, 0x26, 0xfc,
+      0x8e, 0xae, 0x0d, 0x2d, 0x65, 0xc4, 0x2a, 0x47, 0x9f, 0x08, 0x86,
+      0x48, 0xbe, 0x2d, 0xc8, 0x01, 0xd8, 0x2a, 0x36, 0x6f, 0xdd, 0xc0,
+      0xef, 0x23, 0x42, 0x63, 0xc0, 0xb6, 0x41, 0x7d, 0x5f, 0x9d, 0xa4,
+      0x18, 0x17, 0xb8, 0x8d, 0x68, 0xe5, 0xe6, 0x71, 0x95, 0xc5, 0xc1,
+      0xee, 0x30, 0x95, 0xe8, 0x21, 0xf2, 0x25, 0x24, 0xb2, 0x0b, 0xe4,
+      0x1c, 0xeb, 0x59, 0x04, 0x12, 0xe4, 0x1d, 0xc6, 0x48, 0x84, 0x3f,
+      0xa9, 0xbf, 0xec, 0x7a, 0x3d, 0xcf, 0x61, 0xab, 0x05, 0x41, 0x57,
+      0x33, 0x16, 0xd3, 0xfa, 0x81, 0x51, 0x62, 0x93, 0x03, 0xfe, 0x97,
+      0x41, 0x56, 0x2e, 0xd0, 0x65, 0xdb, 0x4e, 0xbc, 0x00, 0x50, 0xef,
+      0x55, 0x83, 0x64, 0xae, 0x81, 0x12, 0x4a, 0x28, 0xf5, 0xc0, 0x13,
+      0x13, 0x23, 0x2f, 0xbc, 0x49, 0x6d, 0xfd, 0x8a, 0x25, 0x68, 0x65,
+      0x7b, 0x68, 0x6d, 0x72, 0x14, 0x38, 0x2a, 0x1a, 0x00, 0x90, 0x30,
+      0x17, 0xdd, 0xa9, 0x69, 0x87, 0x84, 0x42, 0xba, 0x5a, 0xff, 0xf6,
+      0x61, 0x3f, 0x55, 0x3c, 0xbb, 0x23, 0x3c, 0xe4, 0x6d, 0x9a, 0xee,
+      0x93, 0xa7, 0x87, 0x6c, 0xf5, 0xe9, 0xe8, 0x29, 0x12, 0xb1, 0x8c,
+      0xad, 0xf0, 0xb3, 0x43, 0x27, 0xb2, 0xe0, 0x42, 0x7e, 0xcf, 0x66,
+      0xb7, 0xce, 0xb7, 0xc0, 0x91, 0x8d, 0xc4, 0x7b, 0xdf, 0xf1, 0x2a,
+      0x06, 0x2a, 0xdf, 0x07, 0x13, 0x30, 0x09, 0xce, 0x7a, 0x5e, 0x5c,
+      0x91, 0x7e, 0x01, 0x68, 0x30, 0x61, 0x09, 0xb7, 0xcb, 0x49, 0x65,
+      0x3a, 0x6d, 0x2c, 0xae, 0xf0, 0x05, 0xde, 0x78, 0x3a, 0x9a, 0x9b,
+      0xfe, 0x05, 0x38, 0x1e, 0xd1, 0x34, 0x8d, 0x94, 0xec, 0x65, 0x88,
+      0x6f, 0x9c, 0x0b, 0x61, 0x9c, 0x52, 0xc5, 0x53, 0x38, 0x00, 0xb1,
+      0x6c, 0x83, 0x61, 0x72, 0xb9, 0x51, 0x82, 0xdb, 0xc5, 0xee, 0xc0,
+      0x42, 0xb8, 0x9e, 0x22, 0xf1, 0x1a, 0x08, 0x5b, 0x73, 0x9a, 0x36,
+      0x11, 0xcd, 0x8d, 0x83, 0x60, 0x18
+    };
+
+  /* Check with the expected internal arc4random keystream buffer.  Some
+     architecture optimizations expects a buffer with a minimum size which
+     is a multiple of then ChaCha20 blocksize, so they might not be prepared
+     to handle smaller buffers.  */
+
+  uint8_t output[CHACHA20_BUFSIZE];
+
+  uint32_t state[CHACHA20_STATE_LEN];
+  chacha20_init (state, key, iv);
+
+  /* Check with the initial state.  */
+  uint8_t input[CHACHA20_BUFSIZE] = { 0 };
+
+  chacha20_crypt (state, output, input);
+  TEST_COMPARE_BLOB (output, sizeof output, expected1, CHACHA20_BUFSIZE);
+
+  /* And on the next round.  */
+  chacha20_crypt (state, output, input);
+  TEST_COMPARE_BLOB (output, sizeof output, expected2, CHACHA20_BUFSIZE);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/stdlib/tst-arc4random-fork.c b/stdlib/tst-arc4random-fork.c
new file mode 100644
index 0000000000..019c0a99de
--- /dev/null
+++ b/stdlib/tst-arc4random-fork.c
@@ -0,0 +1,198 @@
+/* Test that subprocesses generate distinct streams of randomness.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* Collect random data from subprocesses and check that all the
+   results are unique.  */
+
+#include <array_length.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xthread.h>
+#include <support/xunistd.h>
+#include <unistd.h>
+
+/* Perform multiple runs.  The subsequent runs start with an
+   already-initialized random number generator.  (The number 1500 was
+   seen to reproduce failures reliable in case of a race condition in
+   the fork detection code.)  */
+enum { runs = 1500 };
+
+/* One hundred processes in total.  This should be high enough to
+   expose any issues, but low enough not to tax the overall system too
+   much.  */
+enum { subprocesses = 49 };
+
+/* The total number of processes.  */
+enum { processes = subprocesses + 1 };
+
+/* Number of bytes of randomness to generate per process.  Large
+   enough to make false positive duplicates extremely unlikely.  */
+enum { random_size = 16 };
+
+/* Generated bytes of randomness.  */
+struct result
+{
+  unsigned char bytes[random_size];
+};
+
+/* Shared across all processes.  */
+static struct shared_data
+{
+  pthread_barrier_t barrier;
+  struct result results[runs][processes];
+} *shared_data;
+
+static void
+generate_arc4random (unsigned char *bytes)
+{
+  for (int i = 0; i < random_size / sizeof (uint32_t); i++)
+    {
+      uint32_t x = arc4random ();
+      memcpy (&bytes[4 * i], &x, sizeof x);
+    }
+}
+
+static void
+generate_arc4random_buf (unsigned char *bytes)
+{
+  arc4random_buf (bytes, random_size);
+}
+
+static void
+generate_arc4random_uniform (unsigned char *bytes)
+{
+  for (int i = 0; i < random_size; i++)
+    bytes[i] = arc4random_uniform (256);
+}
+
+/* Invoked to collect data from a subprocess.  */
+static void
+subprocess (int run, int process_index, void (*func)(unsigned char *))
+{
+  xpthread_barrier_wait (&shared_data->barrier);
+  func (shared_data->results[run][process_index].bytes);
+}
+
+/* Used to sort the results.  */
+struct index
+{
+  int run;
+  int process_index;
+};
+
+/* Used to sort an array of struct index values.  */
+static int
+index_compare (const void *left1, const void *right1)
+{
+  const struct index *left = left1;
+  const struct index *right = right1;
+
+  return memcmp (shared_data->results[left->run][left->process_index].bytes,
+                 shared_data->results[right->run][right->process_index].bytes,
+                 random_size);
+}
+
+static int
+do_test_func (void (*func)(unsigned char *bytes))
+{
+  /* Collect random data.  */
+  for (int run = 0; run < runs; ++run)
+    {
+      pid_t pids[subprocesses];
+      for (int process_index = 0; process_index < subprocesses;
+           ++process_index)
+        {
+          pids[process_index] = xfork ();
+          if (pids[process_index] == 0)
+            {
+              subprocess (run, process_index, func);
+              _exit (0);
+            }
+        }
+
+      /* Trigger all subprocesses.  Also add data from the parent
+         process.  */
+      subprocess (run, subprocesses, func);
+
+      for (int process_index = 0; process_index < subprocesses;
+           ++process_index)
+        {
+          int status;
+          xwaitpid (pids[process_index], &status, 0);
+          if (status != 0)
+            FAIL_EXIT1 ("subprocess index %d (PID %d) exit status %d\n",
+                        process_index, (int) pids[process_index], status);
+        }
+    }
+
+  /* Check for duplicates.  */
+  struct index indexes[runs * processes];
+  for (int run = 0; run < runs; ++run)
+    for (int process_index = 0; process_index < processes; ++process_index)
+      indexes[run * processes + process_index]
+        = (struct index) { .run = run, .process_index = process_index };
+  qsort (indexes, array_length (indexes), sizeof (indexes[0]), index_compare);
+  for (size_t i = 1; i < array_length (indexes); ++i)
+    {
+      if (index_compare (indexes + i - 1, indexes + i) == 0)
+        {
+          support_record_failure ();
+          unsigned char *bytes
+            = shared_data->results[indexes[i].run]
+                [indexes[i].process_index].bytes;
+          char *quoted = support_quote_blob (bytes, random_size);
+          printf ("error: duplicate randomness data: \"%s\"\n"
+                  "  run %d, subprocess %d\n"
+                  "  run %d, subprocess %d\n",
+                  quoted, indexes[i - 1].run, indexes[i - 1].process_index,
+                  indexes[i].run, indexes[i].process_index);
+          free (quoted);
+        }
+    }
+
+  return 0;
+}
+
+static int
+do_test (void)
+{
+  shared_data = support_shared_allocate (sizeof (*shared_data));
+  {
+    pthread_barrierattr_t attr;
+    xpthread_barrierattr_init (&attr);
+    xpthread_barrierattr_setpshared (&attr, PTHREAD_PROCESS_SHARED);
+    xpthread_barrier_init (&shared_data->barrier, &attr, processes);
+    xpthread_barrierattr_destroy (&attr);
+  }
+
+  do_test_func (generate_arc4random);
+  do_test_func (generate_arc4random_buf);
+  do_test_func (generate_arc4random_uniform);
+
+  xpthread_barrier_destroy (&shared_data->barrier);
+  support_shared_free (shared_data);
+  shared_data = NULL;
+
+  return 0;
+}
+
+#define TIMEOUT 40
+#include <support/test-driver.c>
diff --git a/stdlib/tst-arc4random-stats.c b/stdlib/tst-arc4random-stats.c
new file mode 100644
index 0000000000..f6fc1f10c4
--- /dev/null
+++ b/stdlib/tst-arc4random-stats.c
@@ -0,0 +1,147 @@
+/* Statistical tests for arc4random-related functions.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <array_length.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <support/check.h>
+
+enum
+{
+  arc4random_key_size = 32
+};
+
+struct key
+{
+  unsigned char data[arc4random_key_size];
+};
+
+/* With 12,000 keys, the probability that a byte in a predetermined
+   position does not have a predetermined value in all generated keys
+   is about 4e-21.  The probability that this happens with any of the
+   16 * 256 possible byte position/values is 1.6e-17.  This results in
+   an acceptably low false-positive rate.  */
+enum { key_count = 12000 };
+
+static struct key keys[key_count];
+
+/* Used to perform the distribution check.  */
+static int byte_counts[arc4random_key_size][256];
+
+/* Bail out after this many failures.  */
+enum { failure_limit = 100 };
+
+static void
+find_stuck_bytes (bool (*func) (unsigned char *key))
+{
+  memset (&keys, 0xcc, sizeof (keys));
+
+  int failures = 0;
+  for (int key = 0; key < key_count; ++key)
+    {
+      while (true)
+        {
+          if (func (keys[key].data))
+            break;
+          ++failures;
+          if (failures >= failure_limit)
+            {
+              printf ("warning: bailing out after %d failures\n", failures);
+              return;
+            }
+        }
+    }
+  printf ("info: key generation finished with %d failures\n", failures);
+
+  memset (&byte_counts, 0, sizeof (byte_counts));
+  for (int key = 0; key < key_count; ++key)
+    for (int pos = 0; pos < arc4random_key_size; ++pos)
+      ++byte_counts[pos][keys[key].data[pos]];
+
+  for (int pos = 0; pos < arc4random_key_size; ++pos)
+    for (int byte = 0; byte < 256; ++byte)
+      if (byte_counts[pos][byte] == 0)
+        {
+          support_record_failure ();
+          printf ("error: byte %d never appeared at position %d\n", byte, pos);
+        }
+}
+
+/* Test adapter for arc4random.  */
+static bool
+generate_arc4random (unsigned char *key)
+{
+  uint32_t words[arc4random_key_size / 4];
+  _Static_assert (sizeof (words) == arc4random_key_size, "sizeof (words)");
+
+  for (int i = 0; i < array_length (words); ++i)
+    words[i] = arc4random ();
+  memcpy (key, &words, arc4random_key_size);
+  return true;
+}
+
+/* Test adapter for arc4random_buf.  */
+static bool
+generate_arc4random_buf (unsigned char *key)
+{
+  arc4random_buf (key, arc4random_key_size);
+  return true;
+}
+
+/* Test adapter for arc4random_uniform.  */
+static bool
+generate_arc4random_uniform (unsigned char *key)
+{
+  for (int i = 0; i < arc4random_key_size; ++i)
+    key[i] = arc4random_uniform (256);
+  return true;
+}
+
+/* Test adapter for arc4random_uniform with argument 257.  This means
+   that byte 0 happens more often, but we do not perform such a
+   statistcal check, so the test will still pass */
+static bool
+generate_arc4random_uniform_257 (unsigned char *key)
+{
+  for (int i = 0; i < arc4random_key_size; ++i)
+    key[i] = arc4random_uniform (257);
+  return true;
+}
+
+static int
+do_test (void)
+{
+  puts ("info: arc4random implementation test");
+  find_stuck_bytes (generate_arc4random);
+
+  puts ("info: arc4random_buf implementation test");
+  find_stuck_bytes (generate_arc4random_buf);
+
+  puts ("info: arc4random_uniform implementation test");
+  find_stuck_bytes (generate_arc4random_uniform);
+
+  puts ("info: arc4random_uniform implementation test (257 variant)");
+  find_stuck_bytes (generate_arc4random_uniform_257);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/stdlib/tst-arc4random-thread.c b/stdlib/tst-arc4random-thread.c
new file mode 100644
index 0000000000..3373d4d446
--- /dev/null
+++ b/stdlib/tst-arc4random-thread.c
@@ -0,0 +1,341 @@
+/* Test that threads generate distinct streams of randomness.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <array_length.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/support.h>
+#include <support/xthread.h>
+
+/* Number of arc4random_buf calls per thread.  */
+enum { count_per_thread = 5000 };
+
+/* Number of threads computing randomness.  */
+enum { inner_threads = 5 };
+
+/* Number of threads launching other threads.  Chosen as to not to
+   overload the system.  */
+enum { outer_threads = 7 };
+
+/* Number of launching rounds performed by the outer threads.  */
+enum { outer_rounds = 10 };
+
+/* Maximum number of bytes generated in an arc4random call.  */
+enum { max_size = 32 };
+
+/* Sizes generated by threads.  Must be long enough to be unique with
+   high probability.  */
+static const int sizes[] = { 12, 15, 16, 17, 24, 31, max_size };
+
+/* Data structure to capture randomness results.  */
+struct blob
+{
+  unsigned int size;
+  int thread_id;
+  unsigned int index;
+  unsigned char bytes[max_size];
+};
+
+struct subprocess_args
+{
+  struct blob *blob;
+  void (*func)(unsigned char *, size_t);
+};
+
+static void
+generate_arc4random (unsigned char *bytes, size_t size)
+{
+  int i;
+  for (i = 0; i < size / sizeof (uint32_t); i++)
+    {
+      uint32_t x = arc4random ();
+      memcpy (&bytes[4 * i], &x, sizeof x);
+    }
+  int rem = size % sizeof (uint32_t);
+  if (rem > 0)
+    {
+      uint32_t x = arc4random ();
+      memcpy (&bytes[4 * i], &x, rem);
+    }
+}
+
+static void
+generate_arc4random_buf (unsigned char *bytes, size_t size)
+{
+  arc4random_buf (bytes, size);
+}
+
+static void
+generate_arc4random_uniform (unsigned char *bytes, size_t size)
+{
+  for (int i = 0; i < size; i++)
+    bytes[i] = arc4random_uniform (256);
+}
+
+#define DYNARRAY_STRUCT dynarray_blob
+#define DYNARRAY_ELEMENT struct blob
+#define DYNARRAY_PREFIX dynarray_blob_
+#include <malloc/dynarray-skeleton.c>
+
+/* Sort blob elements by length first, then by comparing the data
+   member.  */
+static int
+compare_blob (const void *left1, const void *right1)
+{
+  const struct blob *left = left1;
+  const struct blob *right = right1;
+
+  if (left->size != right->size)
+    /* No overflow due to limited range.  */
+    return left->size - right->size;
+  return memcmp (left->bytes, right->bytes, left->size);
+}
+
+/* Used to store the global result.  */
+static pthread_mutex_t global_result_lock = PTHREAD_MUTEX_INITIALIZER;
+static struct dynarray_blob global_result;
+
+/* Copy data to the global result, with locking.  */
+static void
+copy_result_to_global (struct dynarray_blob *result)
+{
+  xpthread_mutex_lock (&global_result_lock);
+  size_t old_size = dynarray_blob_size (&global_result);
+  TEST_VERIFY_EXIT
+    (dynarray_blob_resize (&global_result,
+                           old_size + dynarray_blob_size (result)));
+  memcpy (dynarray_blob_begin (&global_result) + old_size,
+          dynarray_blob_begin (result),
+          dynarray_blob_size (result) * sizeof (struct blob));
+  xpthread_mutex_unlock (&global_result_lock);
+}
+
+/* Used to assign unique thread IDs.  Accessed atomically.  */
+static int next_thread_id;
+
+static void *
+inner_thread (void *closure)
+{
+  void (*func) (unsigned char *, size_t) = closure;
+
+  /* Use local result to avoid global lock contention while generating
+     randomness.  */
+  struct dynarray_blob result;
+  dynarray_blob_init (&result);
+
+  int thread_id = __atomic_fetch_add (&next_thread_id, 1, __ATOMIC_RELAXED);
+
+  /* Determine the sizes to be used by this thread.  */
+  int size_slot = thread_id % (array_length (sizes) + 1);
+  bool switch_sizes = size_slot == array_length (sizes);
+  if (switch_sizes)
+    size_slot = 0;
+
+  /* Compute the random blobs.  */
+  for (int i = 0; i < count_per_thread; ++i)
+    {
+      struct blob *place = dynarray_blob_emplace (&result);
+      TEST_VERIFY_EXIT (place != NULL);
+      place->size = sizes[size_slot];
+      place->thread_id = thread_id;
+      place->index = i;
+      func (place->bytes, place->size);
+
+      if (switch_sizes)
+        size_slot = (size_slot + 1) % array_length (sizes);
+    }
+
+  /* Store the blobs in the global result structure.  */
+  copy_result_to_global (&result);
+
+  dynarray_blob_free (&result);
+
+  return NULL;
+}
+
+/* Launch the inner threads and wait for their termination.  */
+static void *
+outer_thread (void *closure)
+{
+  void (*func) (unsigned char *, size_t) = closure;
+
+  for (int round = 0; round < outer_rounds; ++round)
+    {
+      pthread_t threads[inner_threads];
+
+      for (int i = 0; i < inner_threads; ++i)
+        threads[i] = xpthread_create (NULL, inner_thread, func);
+
+      for (int i = 0; i < inner_threads; ++i)
+        xpthread_join (threads[i]);
+    }
+
+  return NULL;
+}
+
+static bool termination_requested;
+
+/* Call arc4random_buf to fill one blob with 16 bytes.  */
+static void *
+get_one_blob_thread (void *closure)
+{
+  struct subprocess_args *arg = closure;
+  struct blob *result = arg->blob;
+
+  result->size = 16;
+  arg->func (result->bytes, result->size);
+  return NULL;
+}
+
+/* Invoked from fork_thread to actually obtain randomness data.  */
+static void
+fork_thread_subprocess (void *closure)
+{
+  struct subprocess_args *arg = closure;
+  struct blob *shared_result = arg->blob;
+
+  struct subprocess_args args[3] =
+  {
+    { shared_result + 0, arg->func },
+    { shared_result + 1, arg->func },
+    { shared_result + 2, arg->func }
+  };
+
+  pthread_t thr1 = xpthread_create (NULL, get_one_blob_thread, &args[1]);
+  pthread_t thr2 = xpthread_create (NULL, get_one_blob_thread, &args[2]);
+  get_one_blob_thread (&args[0]);
+  xpthread_join (thr1);
+  xpthread_join (thr2);
+}
+
+/* Continuously fork subprocesses to obtain a little bit of
+   randomness.  */
+static void *
+fork_thread (void *closure)
+{
+  void (*func)(unsigned char *, size_t) = closure;
+
+  struct dynarray_blob result;
+  dynarray_blob_init (&result);
+
+  /* Three blobs from each subprocess.  */
+  struct blob *shared_result
+    = support_shared_allocate (3 * sizeof (*shared_result));
+
+  while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED))
+    {
+      /* Obtain the results from a subprocess.  */
+      struct subprocess_args arg = { shared_result, func };
+      support_isolate_in_subprocess (fork_thread_subprocess, &arg);
+
+      for (int i = 0; i < 3; ++i)
+        {
+          struct blob *place = dynarray_blob_emplace (&result);
+          TEST_VERIFY_EXIT (place != NULL);
+          place->size = shared_result[i].size;
+          place->thread_id = -1;
+          place->index = i;
+          memcpy (place->bytes, shared_result[i].bytes, place->size);
+        }
+    }
+
+  support_shared_free (shared_result);
+
+  copy_result_to_global (&result);
+  dynarray_blob_free (&result);
+
+  return NULL;
+}
+
+/* Launch the outer threads and wait for their termination.  */
+static void
+run_outer_threads (void (*func)(unsigned char *, size_t))
+{
+  /* Special thread that continuously calls fork.  */
+  pthread_t fork_thread_id = xpthread_create (NULL, fork_thread, func);
+
+  pthread_t threads[outer_threads];
+  for (int i = 0; i < outer_threads; ++i)
+    threads[i] = xpthread_create (NULL, outer_thread, func);
+
+  for (int i = 0; i < outer_threads; ++i)
+    xpthread_join (threads[i]);
+
+  __atomic_store_n (&termination_requested, true, __ATOMIC_RELAXED);
+  xpthread_join (fork_thread_id);
+}
+
+static int
+do_test_func (const char *fname, void (*func)(unsigned char *, size_t))
+{
+  dynarray_blob_init (&global_result);
+  int expected_blobs
+    = count_per_thread * inner_threads * outer_threads * outer_rounds;
+  printf ("info: %s: minimum of %d blob results expected\n",
+	  fname, expected_blobs);
+
+  run_outer_threads (func);
+
+  /* The forking thread delivers a non-deterministic number of
+     results, which is why expected_blobs is only a minimun number of
+     results.  */
+  printf ("info: %s: %zu blob results observed\n", fname,
+          dynarray_blob_size (&global_result));
+  TEST_VERIFY (dynarray_blob_size (&global_result) >= expected_blobs);
+
+  /* Verify that there are no duplicates.  */
+  qsort (dynarray_blob_begin (&global_result),
+         dynarray_blob_size (&global_result),
+         sizeof (struct blob), compare_blob);
+  struct blob *end = dynarray_blob_end (&global_result);
+  for (struct blob *p = dynarray_blob_begin (&global_result) + 1;
+       p < end; ++p)
+    {
+      if (compare_blob (p - 1, p) == 0)
+        {
+          support_record_failure ();
+          char *quoted = support_quote_blob (p->bytes, p->size);
+          printf ("error: %s: duplicate blob: \"%s\" (%d bytes)\n",
+		  fname, quoted, (int) p->size);
+          printf ("  first source: thread %d, index %u\n",
+                  p[-1].thread_id, p[-1].index);
+          printf ("  second source: thread %d, index %u\n",
+                  p[0].thread_id, p[0].index);
+          free (quoted);
+        }
+    }
+
+  dynarray_blob_free (&global_result);
+
+  return 0;
+}
+
+static int
+do_test (void)
+{
+  do_test_func ("arc4random", generate_arc4random);
+  do_test_func ("arc4random_buf", generate_arc4random_buf);
+  do_test_func ("arc4random_uniform", generate_arc4random_uniform);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH v12 3/9] benchtests: Add arc4random benchtest
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417) Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 2/9] stdlib: Add arc4random tests Adhemerval Zanella
@ 2022-07-22 12:21 ` Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 4/9] aarch64: Add optimized chacha20 Adhemerval Zanella
                   ` (6 subsequent siblings)
  9 siblings, 0 replies; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

It shows both throughput (total bytes obtained in the test duration)
and latecy for both arc4random and arc4random_buf with different
sizes.

Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu.
---
 benchtests/Makefile                  |   5 +-
 benchtests/bench-arc4random.c        | 218 +++++++++++++++++++++++++++
 benchtests/bench-hash-funcs-kernel.h |   1 +
 benchtests/bench-hash-funcs.c        |   2 -
 benchtests/bench-util.h              |   7 +
 5 files changed, 230 insertions(+), 3 deletions(-)
 create mode 100644 benchtests/bench-arc4random.c

diff --git a/benchtests/Makefile b/benchtests/Makefile
index c279041e19..d99771be74 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -233,7 +233,10 @@ hash-benchset := \
   nss-hash \
 # hash-benchset
 
-stdlib-benchset := strtod
+stdlib-benchset := \
+  arc4random \
+  strtod \
+  # stdlib-benchset
 
 stdio-common-benchset := sprintf
 
diff --git a/benchtests/bench-arc4random.c b/benchtests/bench-arc4random.c
new file mode 100644
index 0000000000..d8fd40298e
--- /dev/null
+++ b/benchtests/bench-arc4random.c
@@ -0,0 +1,218 @@
+/* arc4random benchmarks.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include "bench-timing.h"
+#include "bench-util.h"
+#include "json-lib.h"
+#include <array_length.h>
+#include <intprops.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <support/support.h>
+#include <support/timespec.h>
+#include <support/xthread.h>
+
+static volatile sig_atomic_t timer_finished;
+
+static void timer_callback (int unused)
+{
+  timer_finished = 1;
+}
+
+static timer_t timer;
+
+/* Run for approximately DURATION seconds, and it does not matter who
+   receive the signal (so not need to mask it on main thread).  */
+static void
+timer_start (void)
+{
+  timer_finished = 0;
+  timer = support_create_timer (DURATION, 0, false, timer_callback);
+}
+static void
+timer_stop (void)
+{
+  support_delete_timer (timer);
+}
+
+static const uint32_t sizes[] = { 0, 16, 32, 48, 64, 80, 96, 112, 128 };
+
+static double
+bench_throughput (void)
+{
+  uint64_t n = 0;
+
+  struct timespec start, end;
+  clock_gettime (CLOCK_MONOTONIC, &start);
+  while (1)
+    {
+      DO_NOT_OPTIMIZE_OUT (arc4random ());
+      n++;
+
+      if (timer_finished == 1)
+	break;
+    }
+  clock_gettime (CLOCK_MONOTONIC, &end);
+  struct timespec diff = timespec_sub (end, start);
+
+  double total = (double) n * sizeof (uint32_t);
+  double duration = (double) diff.tv_sec
+    + (double) diff.tv_nsec / TIMESPEC_HZ;
+
+  return total / duration;
+}
+
+static double
+bench_latency (void)
+{
+  timing_t start, stop, cur;
+  const size_t iters = 1024;
+
+  TIMING_NOW (start);
+  for (size_t i = 0; i < iters; i++)
+    DO_NOT_OPTIMIZE_OUT (arc4random ());
+  TIMING_NOW (stop);
+
+  TIMING_DIFF (cur, start, stop);
+
+  return (double) (cur) / (double) iters;
+}
+
+static double
+bench_buf_throughput (size_t len)
+{
+  uint8_t buf[len];
+  uint64_t n = 0;
+
+  struct timespec start, end;
+  clock_gettime (CLOCK_MONOTONIC, &start);
+  while (1)
+    {
+      arc4random_buf (buf, len);
+      n++;
+
+      if (timer_finished == 1)
+	break;
+    }
+  clock_gettime (CLOCK_MONOTONIC, &end);
+  struct timespec diff = timespec_sub (end, start);
+
+  double total = (double) n * len;
+  double duration = (double) diff.tv_sec
+    + (double) diff.tv_nsec / TIMESPEC_HZ;
+
+  return total / duration;
+}
+
+static double
+bench_buf_latency (size_t len)
+{
+  timing_t start, stop, cur;
+  const size_t iters = 1024;
+
+  uint8_t buf[len];
+
+  TIMING_NOW (start);
+  for (size_t i = 0; i < iters; i++)
+    arc4random_buf (buf, len);
+  TIMING_NOW (stop);
+
+  TIMING_DIFF (cur, start, stop);
+
+  return (double) (cur) / (double) iters;
+}
+
+static void
+bench_singlethread (json_ctx_t *json_ctx)
+{
+  json_element_object_begin (json_ctx);
+
+  json_array_begin (json_ctx, "throughput");
+  for (int i = 0; i < array_length (sizes); i++)
+    {
+      timer_start ();
+      double r = sizes[i] == 0
+	? bench_throughput () : bench_buf_throughput (sizes[i]);
+      timer_stop ();
+
+      json_element_double (json_ctx, r);
+    }
+  json_array_end (json_ctx);
+
+  json_array_begin (json_ctx, "latency");
+  for (int i = 0; i < array_length (sizes); i++)
+    {
+      timer_start ();
+      double r = sizes[i] == 0
+	? bench_latency () : bench_buf_latency (sizes[i]);
+      timer_stop ();
+
+      json_element_double (json_ctx, r);
+    }
+  json_array_end (json_ctx);
+
+  json_element_object_end (json_ctx);
+}
+
+static void
+run_bench (json_ctx_t *json_ctx, const char *name,
+	   char *const*fnames, size_t fnameslen,
+	   void (*bench) (json_ctx_t *ctx))
+{
+  json_attr_object_begin (json_ctx, name);
+  json_array_begin (json_ctx, "functions");
+  for (int i = 0; i < fnameslen; i++)
+    json_element_string (json_ctx, fnames[i]);
+  json_array_end (json_ctx);
+
+  json_array_begin (json_ctx, "results");
+  bench (json_ctx);
+  json_array_end (json_ctx);
+  json_attr_object_end (json_ctx);
+}
+
+static int
+do_test (void)
+{
+  char *fnames[array_length (sizes)];
+  for (int i = 0; i < array_length (sizes); i++)
+    if (sizes[i] == 0)
+      fnames[i] = xasprintf ("arc4random");
+    else
+      fnames[i] = xasprintf ("arc4random_buf(%u)", sizes[i]);
+
+  json_ctx_t json_ctx;
+  json_init (&json_ctx, 0, stdout);
+
+  json_document_begin (&json_ctx);
+  json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
+
+  run_bench (&json_ctx, "single-thread", fnames, array_length (fnames),
+	     bench_singlethread);
+
+  json_document_end (&json_ctx);
+
+  for (int i = 0; i < array_length (sizes); i++)
+    free (fnames[i]);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/benchtests/bench-hash-funcs-kernel.h b/benchtests/bench-hash-funcs-kernel.h
index 83995cc0ae..63034f7e44 100644
--- a/benchtests/bench-hash-funcs-kernel.h
+++ b/benchtests/bench-hash-funcs-kernel.h
@@ -17,6 +17,7 @@
    <https://www.gnu.org/licenses/>.  */
 
 
+#include "bench-util.h"
 
 /* We go through the trouble of using macros here because many of the
    hash functions are meant to be inlined so its not fair to benchmark
diff --git a/benchtests/bench-hash-funcs.c b/benchtests/bench-hash-funcs.c
index 578c5cbae2..44b349d30c 100644
--- a/benchtests/bench-hash-funcs.c
+++ b/benchtests/bench-hash-funcs.c
@@ -38,8 +38,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#define DO_NOT_OPTIMIZE_OUT(x) __asm__ volatile("" : : "r,m"(x) : "memory")
-
 enum
 {
   NFIXED_ITERS = 1048576,
diff --git a/benchtests/bench-util.h b/benchtests/bench-util.h
index d0e29423aa..00f78d649f 100644
--- a/benchtests/bench-util.h
+++ b/benchtests/bench-util.h
@@ -16,6 +16,13 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+/* Prevent compiler to optimize away call.  */
+#define DO_NOT_OPTIMIZE_OUT(value)		  \
+  ({						  \
+    __typeof (value) __v = (value);		  \
+    asm volatile ("" : : "r,m" (__v) : "memory"); \
+    __v;					  \
+  })
 
 #ifndef START_ITER
 # define START_ITER (100000000)
-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH v12 4/9] aarch64: Add optimized chacha20
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
                   ` (2 preceding siblings ...)
  2022-07-22 12:21 ` [PATCH v12 3/9] benchtests: Add arc4random benchtest Adhemerval Zanella
@ 2022-07-22 12:21 ` Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 5/9] x86: Add SSE2 " Adhemerval Zanella
                   ` (5 subsequent siblings)
  9 siblings, 0 replies; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

It adds vectorized ChaCha20 implementation based on libgcrypt
cipher/chacha20-aarch64.S.  It is used as default and only
little-endian is supported (BE uses generic code).

As for generic implementation, the last step that XOR with the
input is omited.  The final state register clearing is also
omitted.

On a virtualized Linux on Apple M1 it shows the following
improvements (using formatted bench-arc4random data):

GENERIC                                    MB/s
-----------------------------------------------
arc4random [single-thread]               380.89
arc4random_buf(16) [single-thread]       500.73
arc4random_buf(32) [single-thread]       552.61
arc4random_buf(48) [single-thread]       566.82
arc4random_buf(64) [single-thread]       574.01
arc4random_buf(80) [single-thread]       581.02
arc4random_buf(96) [single-thread]       591.19
arc4random_buf(112) [single-thread]      592.29
arc4random_buf(128) [single-thread]      596.43
-----------------------------------------------

OPTIMIZED                                  MB/s
-----------------------------------------------
arc4random [single-thread]               569.60
arc4random_buf(16) [single-thread]       825.78
arc4random_buf(32) [single-thread]       987.03
arc4random_buf(48) [single-thread]      1042.39
arc4random_buf(64) [single-thread]      1075.50
arc4random_buf(80) [single-thread]      1094.68
arc4random_buf(96) [single-thread]      1130.16
arc4random_buf(112) [single-thread]     1129.58
arc4random_buf(128) [single-thread]     1137.91
-----------------------------------------------

Checked on aarch64-linux-gnu.
---
 LICENSES                           |  20 ++
 stdlib/chacha20.c                  |   6 +-
 sysdeps/aarch64/Makefile           |   4 +
 sysdeps/aarch64/chacha20-aarch64.S | 314 +++++++++++++++++++++++++++++
 sysdeps/aarch64/chacha20_arch.h    |  39 ++++
 sysdeps/generic/chacha20_arch.h    |  23 +++
 6 files changed, 405 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/aarch64/chacha20-aarch64.S
 create mode 100644 sysdeps/aarch64/chacha20_arch.h
 create mode 100644 sysdeps/generic/chacha20_arch.h

diff --git a/LICENSES b/LICENSES
index 530893b1dc..b1fbfc6904 100644
--- a/LICENSES
+++ b/LICENSES
@@ -389,3 +389,23 @@ Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, see
  <https://www.gnu.org/licenses/>.  */
+\f
+sysdeps/aarch64/chacha20-aarch64.S imports code from libgcrypt, with
+the following notices:
+
+Copyright (C) 2017-2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+
+This file is part of Libgcrypt.
+
+Libgcrypt is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as
+published by the Free Software Foundation; either version 2.1 of
+the License, or (at your option) any later version.
+
+Libgcrypt is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this program; if not, see <https://www.gnu.org/licenses/>.
diff --git a/stdlib/chacha20.c b/stdlib/chacha20.c
index 77e37655cd..07b7b203f2 100644
--- a/stdlib/chacha20.c
+++ b/stdlib/chacha20.c
@@ -165,7 +165,8 @@ chacha20_block (uint32_t *state, uint8_t *dst, const uint8_t *src)
 }
 
 static void
-chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
+__attribute_maybe_unused__
+chacha20_crypt_generic (uint32_t *state, uint8_t *dst, const uint8_t *src)
 {
   size_t bytes = CHACHA20_BUFSIZE;
   while (bytes >= CHACHA20_BLOCK_SIZE)
@@ -177,3 +178,6 @@ chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
       src += CHACHA20_BLOCK_SIZE;
     }
 }
+
+/* Get the architecture optimized version.  */
+#include <chacha20_arch.h>
diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile
index 17fb1c5b72..7dfd1b62dd 100644
--- a/sysdeps/aarch64/Makefile
+++ b/sysdeps/aarch64/Makefile
@@ -51,6 +51,10 @@ ifeq ($(subdir),csu)
 gen-as-const-headers += tlsdesc.sym
 endif
 
+ifeq ($(subdir),stdlib)
+sysdep_routines += chacha20-aarch64
+endif
+
 ifeq ($(subdir),gmon)
 CFLAGS-mcount.c += -mgeneral-regs-only
 endif
diff --git a/sysdeps/aarch64/chacha20-aarch64.S b/sysdeps/aarch64/chacha20-aarch64.S
new file mode 100644
index 0000000000..cce5291c5c
--- /dev/null
+++ b/sysdeps/aarch64/chacha20-aarch64.S
@@ -0,0 +1,314 @@
+/* Optimized AArch64 implementation of ChaCha20 cipher.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* Copyright (C) 2017-2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+
+   This file is part of Libgcrypt.
+
+   Libgcrypt is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of
+   the License, or (at your option) any later version.
+
+   Libgcrypt is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+/* Based on D. J. Bernstein reference implementation at
+   http://cr.yp.to/chacha.html:
+
+   chacha-regs.c version 20080118
+   D. J. Bernstein
+   Public domain.  */
+
+#include <sysdep.h>
+
+/* Only LE is supported.  */
+#ifdef __AARCH64EL__
+
+#define GET_DATA_POINTER(reg, name) \
+        adrp    reg, name ; \
+        add     reg, reg, :lo12:name
+
+/* 'ret' instruction replacement for straight-line speculation mitigation */
+#define ret_spec_stop \
+        ret; dsb sy; isb;
+
+.cpu generic+simd
+
+.text
+
+/* register macros */
+#define INPUT     x0
+#define DST       x1
+#define SRC       x2
+#define NBLKS     x3
+#define ROUND     x4
+#define INPUT_CTR x5
+#define INPUT_POS x6
+#define CTR       x7
+
+/* vector registers */
+#define X0 v16
+#define X4 v17
+#define X8 v18
+#define X12 v19
+
+#define X1 v20
+#define X5 v21
+
+#define X9 v22
+#define X13 v23
+#define X2 v24
+#define X6 v25
+
+#define X3 v26
+#define X7 v27
+#define X11 v28
+#define X15 v29
+
+#define X10 v30
+#define X14 v31
+
+#define VCTR    v0
+#define VTMP0   v1
+#define VTMP1   v2
+#define VTMP2   v3
+#define VTMP3   v4
+#define X12_TMP v5
+#define X13_TMP v6
+#define ROT8    v7
+
+/**********************************************************************
+  helper macros
+ **********************************************************************/
+
+#define _(...) __VA_ARGS__
+
+#define vpunpckldq(s1, s2, dst) \
+	zip1 dst.4s, s2.4s, s1.4s;
+
+#define vpunpckhdq(s1, s2, dst) \
+	zip2 dst.4s, s2.4s, s1.4s;
+
+#define vpunpcklqdq(s1, s2, dst) \
+	zip1 dst.2d, s2.2d, s1.2d;
+
+#define vpunpckhqdq(s1, s2, dst) \
+	zip2 dst.2d, s2.2d, s1.2d;
+
+/* 4x4 32-bit integer matrix transpose */
+#define transpose_4x4(x0, x1, x2, x3, t1, t2, t3) \
+	vpunpckhdq(x1, x0, t2); \
+	vpunpckldq(x1, x0, x0); \
+	\
+	vpunpckldq(x3, x2, t1); \
+	vpunpckhdq(x3, x2, x2); \
+	\
+	vpunpckhqdq(t1, x0, x1); \
+	vpunpcklqdq(t1, x0, x0); \
+	\
+	vpunpckhqdq(x2, t2, x3); \
+	vpunpcklqdq(x2, t2, x2);
+
+/**********************************************************************
+  4-way chacha20
+ **********************************************************************/
+
+#define XOR(d,s1,s2) \
+	eor d.16b, s2.16b, s1.16b;
+
+#define PLUS(ds,s) \
+	add ds.4s, ds.4s, s.4s;
+
+#define ROTATE4(dst1,dst2,dst3,dst4,c,src1,src2,src3,src4) \
+	shl dst1.4s, src1.4s, #(c);		\
+	shl dst2.4s, src2.4s, #(c);		\
+	shl dst3.4s, src3.4s, #(c);		\
+	shl dst4.4s, src4.4s, #(c);		\
+	sri dst1.4s, src1.4s, #(32 - (c));	\
+	sri dst2.4s, src2.4s, #(32 - (c));	\
+	sri dst3.4s, src3.4s, #(32 - (c));	\
+	sri dst4.4s, src4.4s, #(32 - (c));
+
+#define ROTATE4_8(dst1,dst2,dst3,dst4,src1,src2,src3,src4) \
+	tbl dst1.16b, {src1.16b}, ROT8.16b;     \
+	tbl dst2.16b, {src2.16b}, ROT8.16b;	\
+	tbl dst3.16b, {src3.16b}, ROT8.16b;	\
+	tbl dst4.16b, {src4.16b}, ROT8.16b;
+
+#define ROTATE4_16(dst1,dst2,dst3,dst4,src1,src2,src3,src4) \
+	rev32 dst1.8h, src1.8h;			\
+	rev32 dst2.8h, src2.8h;			\
+	rev32 dst3.8h, src3.8h;			\
+	rev32 dst4.8h, src4.8h;
+
+#define QUARTERROUND4(a1,b1,c1,d1,a2,b2,c2,d2,a3,b3,c3,d3,a4,b4,c4,d4,ign,tmp1,tmp2,tmp3,tmp4) \
+	PLUS(a1,b1); PLUS(a2,b2);						\
+	PLUS(a3,b3); PLUS(a4,b4);						\
+	    XOR(tmp1,d1,a1); XOR(tmp2,d2,a2);					\
+	    XOR(tmp3,d3,a3); XOR(tmp4,d4,a4);					\
+		ROTATE4_16(d1, d2, d3, d4, tmp1, tmp2, tmp3, tmp4);		\
+	PLUS(c1,d1); PLUS(c2,d2);						\
+	PLUS(c3,d3); PLUS(c4,d4);						\
+	    XOR(tmp1,b1,c1); XOR(tmp2,b2,c2);					\
+	    XOR(tmp3,b3,c3); XOR(tmp4,b4,c4);					\
+		ROTATE4(b1, b2, b3, b4, 12, tmp1, tmp2, tmp3, tmp4)		\
+	PLUS(a1,b1); PLUS(a2,b2);						\
+	PLUS(a3,b3); PLUS(a4,b4);						\
+	    XOR(tmp1,d1,a1); XOR(tmp2,d2,a2);					\
+	    XOR(tmp3,d3,a3); XOR(tmp4,d4,a4);					\
+		ROTATE4_8(d1, d2, d3, d4, tmp1, tmp2, tmp3, tmp4)		\
+	PLUS(c1,d1); PLUS(c2,d2);						\
+	PLUS(c3,d3); PLUS(c4,d4);						\
+	    XOR(tmp1,b1,c1); XOR(tmp2,b2,c2);					\
+	    XOR(tmp3,b3,c3); XOR(tmp4,b4,c4);					\
+		ROTATE4(b1, b2, b3, b4, 7, tmp1, tmp2, tmp3, tmp4)		\
+
+.align 4
+L(__chacha20_blocks4_data_inc_counter):
+	.long 0,1,2,3
+
+.align 4
+L(__chacha20_blocks4_data_rot8):
+	.byte 3,0,1,2
+	.byte 7,4,5,6
+	.byte 11,8,9,10
+	.byte 15,12,13,14
+
+.hidden __chacha20_neon_blocks4
+ENTRY (__chacha20_neon_blocks4)
+	/* input:
+	 *	x0: input
+	 *	x1: dst
+	 *	x2: src
+	 *	x3: nblks (multiple of 4)
+	 */
+
+	GET_DATA_POINTER(CTR, L(__chacha20_blocks4_data_rot8))
+	add INPUT_CTR, INPUT, #(12*4);
+	ld1 {ROT8.16b}, [CTR];
+	GET_DATA_POINTER(CTR, L(__chacha20_blocks4_data_inc_counter))
+	mov INPUT_POS, INPUT;
+	ld1 {VCTR.16b}, [CTR];
+
+L(loop4):
+	/* Construct counter vectors X12 and X13 */
+
+	ld1 {X15.16b}, [INPUT_CTR];
+	mov ROUND, #20;
+	ld1 {VTMP1.16b-VTMP3.16b}, [INPUT_POS];
+
+	dup X12.4s, X15.s[0];
+	dup X13.4s, X15.s[1];
+	ldr CTR, [INPUT_CTR];
+	add X12.4s, X12.4s, VCTR.4s;
+	dup X0.4s, VTMP1.s[0];
+	dup X1.4s, VTMP1.s[1];
+	dup X2.4s, VTMP1.s[2];
+	dup X3.4s, VTMP1.s[3];
+	dup X14.4s, X15.s[2];
+	cmhi VTMP0.4s, VCTR.4s, X12.4s;
+	dup X15.4s, X15.s[3];
+	add CTR, CTR, #4; /* Update counter */
+	dup X4.4s, VTMP2.s[0];
+	dup X5.4s, VTMP2.s[1];
+	dup X6.4s, VTMP2.s[2];
+	dup X7.4s, VTMP2.s[3];
+	sub X13.4s, X13.4s, VTMP0.4s;
+	dup X8.4s, VTMP3.s[0];
+	dup X9.4s, VTMP3.s[1];
+	dup X10.4s, VTMP3.s[2];
+	dup X11.4s, VTMP3.s[3];
+	mov X12_TMP.16b, X12.16b;
+	mov X13_TMP.16b, X13.16b;
+	str CTR, [INPUT_CTR];
+
+L(round2):
+	subs ROUND, ROUND, #2
+	QUARTERROUND4(X0, X4,  X8, X12,   X1, X5,  X9, X13,
+		      X2, X6, X10, X14,   X3, X7, X11, X15,
+		      tmp:=,VTMP0,VTMP1,VTMP2,VTMP3)
+	QUARTERROUND4(X0, X5, X10, X15,   X1, X6, X11, X12,
+		      X2, X7,  X8, X13,   X3, X4,  X9, X14,
+		      tmp:=,VTMP0,VTMP1,VTMP2,VTMP3)
+	b.ne L(round2);
+
+	ld1 {VTMP0.16b, VTMP1.16b}, [INPUT_POS], #32;
+
+	PLUS(X12, X12_TMP);        /* INPUT + 12 * 4 + counter */
+	PLUS(X13, X13_TMP);        /* INPUT + 13 * 4 + counter */
+
+	dup VTMP2.4s, VTMP0.s[0]; /* INPUT + 0 * 4 */
+	dup VTMP3.4s, VTMP0.s[1]; /* INPUT + 1 * 4 */
+	dup X12_TMP.4s, VTMP0.s[2]; /* INPUT + 2 * 4 */
+	dup X13_TMP.4s, VTMP0.s[3]; /* INPUT + 3 * 4 */
+	PLUS(X0, VTMP2);
+	PLUS(X1, VTMP3);
+	PLUS(X2, X12_TMP);
+	PLUS(X3, X13_TMP);
+
+	dup VTMP2.4s, VTMP1.s[0]; /* INPUT + 4 * 4 */
+	dup VTMP3.4s, VTMP1.s[1]; /* INPUT + 5 * 4 */
+	dup X12_TMP.4s, VTMP1.s[2]; /* INPUT + 6 * 4 */
+	dup X13_TMP.4s, VTMP1.s[3]; /* INPUT + 7 * 4 */
+	ld1 {VTMP0.16b, VTMP1.16b}, [INPUT_POS];
+	mov INPUT_POS, INPUT;
+	PLUS(X4, VTMP2);
+	PLUS(X5, VTMP3);
+	PLUS(X6, X12_TMP);
+	PLUS(X7, X13_TMP);
+
+	dup VTMP2.4s, VTMP0.s[0]; /* INPUT + 8 * 4 */
+	dup VTMP3.4s, VTMP0.s[1]; /* INPUT + 9 * 4 */
+	dup X12_TMP.4s, VTMP0.s[2]; /* INPUT + 10 * 4 */
+	dup X13_TMP.4s, VTMP0.s[3]; /* INPUT + 11 * 4 */
+	dup VTMP0.4s, VTMP1.s[2]; /* INPUT + 14 * 4 */
+	dup VTMP1.4s, VTMP1.s[3]; /* INPUT + 15 * 4 */
+	PLUS(X8, VTMP2);
+	PLUS(X9, VTMP3);
+	PLUS(X10, X12_TMP);
+	PLUS(X11, X13_TMP);
+	PLUS(X14, VTMP0);
+	PLUS(X15, VTMP1);
+
+	transpose_4x4(X0, X1, X2, X3, VTMP0, VTMP1, VTMP2);
+	transpose_4x4(X4, X5, X6, X7, VTMP0, VTMP1, VTMP2);
+	transpose_4x4(X8, X9, X10, X11, VTMP0, VTMP1, VTMP2);
+	transpose_4x4(X12, X13, X14, X15, VTMP0, VTMP1, VTMP2);
+
+	subs NBLKS, NBLKS, #4;
+
+	st1 {X0.16b,X4.16B,X8.16b, X12.16b}, [DST], #64
+	st1 {X1.16b,X5.16b}, [DST], #32;
+	st1 {X9.16b, X13.16b, X2.16b, X6.16b}, [DST], #64
+	st1 {X10.16b,X14.16b}, [DST], #32;
+	st1 {X3.16b, X7.16b, X11.16b, X15.16b}, [DST], #64;
+
+	b.ne L(loop4);
+
+	ret_spec_stop
+END (__chacha20_neon_blocks4)
+
+#endif
diff --git a/sysdeps/aarch64/chacha20_arch.h b/sysdeps/aarch64/chacha20_arch.h
new file mode 100644
index 0000000000..c2a94c0590
--- /dev/null
+++ b/sysdeps/aarch64/chacha20_arch.h
@@ -0,0 +1,39 @@
+/* Chacha20 implementation, used on arc4random.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <ldsodefs.h>
+#include <stdbool.h>
+
+unsigned int __chacha20_neon_blocks4 (uint32_t *state, uint8_t *dst,
+				      const uint8_t *src, size_t nblks)
+     attribute_hidden;
+
+static void
+chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
+{
+  _Static_assert (CHACHA20_BUFSIZE % 4 == 0,
+		  "CHACHA20_BUFSIZE not multiple of 4");
+  _Static_assert (CHACHA20_BUFSIZE > CHACHA20_BLOCK_SIZE * 4,
+		  "CHACHA20_BUFSIZE <= CHACHA20_BLOCK_SIZE * 4");
+#ifdef __AARCH64EL__
+  __chacha20_neon_blocks4 (state, dst, src,
+			   CHACHA20_BUFSIZE / CHACHA20_BLOCK_SIZE);
+#else
+  chacha20_crypt_generic (state, dst, src);
+#endif
+}
diff --git a/sysdeps/generic/chacha20_arch.h b/sysdeps/generic/chacha20_arch.h
new file mode 100644
index 0000000000..bcb47eba84
--- /dev/null
+++ b/sysdeps/generic/chacha20_arch.h
@@ -0,0 +1,23 @@
+/* Chacha20 implementation, generic interface for encrypt.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+static inline void
+chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
+{
+  chacha20_crypt_generic (state, dst, src);
+}
-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH v12 5/9] x86: Add SSE2 optimized chacha20
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
                   ` (3 preceding siblings ...)
  2022-07-22 12:21 ` [PATCH v12 4/9] aarch64: Add optimized chacha20 Adhemerval Zanella
@ 2022-07-22 12:21 ` Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 6/9] x86: Add AVX2 " Adhemerval Zanella
                   ` (4 subsequent siblings)
  9 siblings, 0 replies; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

It adds vectorized ChaCha20 implementation based on libgcrypt
cipher/chacha20-amd64-ssse3.S.  It replaces the ROTATE_SHUF_2 (which
uses pshufb) by ROTATE2 and thus making the original implementation
SSE2.

As for generic implementation, the last step that XOR with the
input is omited. The final state register clearing is also
omitted.

On a Ryzen 9 5900X it shows the following improvements (using
formatted bench-arc4random data):

GENERIC                                    MB/s
-----------------------------------------------
arc4random [single-thread]               443.11
arc4random_buf(16) [single-thread]       552.27
arc4random_buf(32) [single-thread]       626.86
arc4random_buf(48) [single-thread]       649.81
arc4random_buf(64) [single-thread]       663.95
arc4random_buf(80) [single-thread]       674.78
arc4random_buf(96) [single-thread]       675.17
arc4random_buf(112) [single-thread]      680.69
arc4random_buf(128) [single-thread]      683.20
-----------------------------------------------

SSE                                        MB/s
-----------------------------------------------
arc4random [single-thread]               704.25
arc4random_buf(16) [single-thread]      1018.17
arc4random_buf(32) [single-thread]      1315.27
arc4random_buf(48) [single-thread]      1449.36
arc4random_buf(64) [single-thread]      1511.16
arc4random_buf(80) [single-thread]      1539.48
arc4random_buf(96) [single-thread]      1571.06
arc4random_buf(112) [single-thread]     1596.16
arc4random_buf(128) [single-thread]     1613.48
-----------------------------------------------

Checked on x86_64-linux-gnu.
---
 LICENSES                             |   4 +-
 sysdeps/x86_64/Makefile              |   6 +
 sysdeps/x86_64/chacha20-amd64-sse2.S | 306 +++++++++++++++++++++++++++
 sysdeps/x86_64/chacha20_arch.h       |  37 ++++
 4 files changed, 351 insertions(+), 2 deletions(-)
 create mode 100644 sysdeps/x86_64/chacha20-amd64-sse2.S
 create mode 100644 sysdeps/x86_64/chacha20_arch.h

diff --git a/LICENSES b/LICENSES
index b1fbfc6904..f0117ef79f 100644
--- a/LICENSES
+++ b/LICENSES
@@ -390,8 +390,8 @@ Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>
  License along with this library; if not, see
  <https://www.gnu.org/licenses/>.  */
 \f
-sysdeps/aarch64/chacha20-aarch64.S imports code from libgcrypt, with
-the following notices:
+sysdeps/aarch64/chacha20-aarch64.S and sysdeps/x86_64/chacha20-amd64-sse2.S
+imports code from libgcrypt, with the following notices:
 
 Copyright (C) 2017-2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
 
diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
index c19bef2dec..3acd9755a5 100644
--- a/sysdeps/x86_64/Makefile
+++ b/sysdeps/x86_64/Makefile
@@ -5,6 +5,12 @@ ifeq ($(subdir),csu)
 gen-as-const-headers += link-defines.sym
 endif
 
+ifeq ($(subdir),stdlib)
+sysdep_routines += \
+  chacha20-amd64-sse2 \
+  # sysdep_routines
+endif
+
 ifeq ($(subdir),gmon)
 sysdep_routines += _mcount
 # We cannot compile _mcount.S with -pg because that would create
diff --git a/sysdeps/x86_64/chacha20-amd64-sse2.S b/sysdeps/x86_64/chacha20-amd64-sse2.S
new file mode 100644
index 0000000000..1178f06306
--- /dev/null
+++ b/sysdeps/x86_64/chacha20-amd64-sse2.S
@@ -0,0 +1,306 @@
+/* Optimized SSE2 implementation of ChaCha20 cipher.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* chacha20-amd64-ssse3.S  -  SSSE3 implementation of ChaCha20 cipher
+
+   Copyright (C) 2017-2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+
+   This file is part of Libgcrypt.
+
+   Libgcrypt is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of
+   the License, or (at your option) any later version.
+
+   Libgcrypt is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, see <https://www.gnu.org/licenses/>.
+*/
+
+/* Based on D. J. Bernstein reference implementation at
+   http://cr.yp.to/chacha.html:
+
+   chacha-regs.c version 20080118
+   D. J. Bernstein
+   Public domain.  */
+
+#include <sysdep.h>
+
+#ifdef PIC
+#  define rRIP (%rip)
+#else
+#  define rRIP
+#endif
+
+/* 'ret' instruction replacement for straight-line speculation mitigation */
+#define ret_spec_stop \
+        ret; int3;
+
+/* register macros */
+#define INPUT %rdi
+#define DST   %rsi
+#define SRC   %rdx
+#define NBLKS %rcx
+#define ROUND %eax
+
+/* stack structure */
+#define STACK_VEC_X12 (16)
+#define STACK_VEC_X13 (16 + STACK_VEC_X12)
+#define STACK_TMP     (16 + STACK_VEC_X13)
+#define STACK_TMP1    (16 + STACK_TMP)
+#define STACK_TMP2    (16 + STACK_TMP1)
+
+#define STACK_MAX     (16 + STACK_TMP2)
+
+/* vector registers */
+#define X0 %xmm0
+#define X1 %xmm1
+#define X2 %xmm2
+#define X3 %xmm3
+#define X4 %xmm4
+#define X5 %xmm5
+#define X6 %xmm6
+#define X7 %xmm7
+#define X8 %xmm8
+#define X9 %xmm9
+#define X10 %xmm10
+#define X11 %xmm11
+#define X12 %xmm12
+#define X13 %xmm13
+#define X14 %xmm14
+#define X15 %xmm15
+
+/**********************************************************************
+  helper macros
+ **********************************************************************/
+
+/* 4x4 32-bit integer matrix transpose */
+#define TRANSPOSE_4x4(x0, x1, x2, x3, t1, t2, t3) \
+	movdqa    x0, t2; \
+	punpckhdq x1, t2; \
+	punpckldq x1, x0; \
+	\
+	movdqa    x2, t1; \
+	punpckldq x3, t1; \
+	punpckhdq x3, x2; \
+	\
+	movdqa     x0, x1; \
+	punpckhqdq t1, x1; \
+	punpcklqdq t1, x0; \
+	\
+	movdqa     t2, x3; \
+	punpckhqdq x2, x3; \
+	punpcklqdq x2, t2; \
+	movdqa     t2, x2;
+
+/* fill xmm register with 32-bit value from memory */
+#define PBROADCASTD(mem32, xreg) \
+	movd mem32, xreg; \
+	pshufd $0, xreg, xreg;
+
+/**********************************************************************
+  4-way chacha20
+ **********************************************************************/
+
+#define ROTATE2(v1,v2,c,tmp1,tmp2)	\
+	movdqa v1, tmp1; 		\
+	movdqa v2, tmp2; 		\
+	psrld $(32 - (c)), v1;		\
+	pslld $(c), tmp1;		\
+	paddb tmp1, v1;			\
+	psrld $(32 - (c)), v2;		\
+	pslld $(c), tmp2;		\
+	paddb tmp2, v2;
+
+#define XOR(ds,s) \
+	pxor s, ds;
+
+#define PLUS(ds,s) \
+	paddd s, ds;
+
+#define QUARTERROUND2(a1,b1,c1,d1,a2,b2,c2,d2,ign,tmp1,tmp2)	\
+	PLUS(a1,b1); PLUS(a2,b2); XOR(d1,a1); XOR(d2,a2);	\
+	    ROTATE2(d1, d2, 16, tmp1, tmp2);			\
+	PLUS(c1,d1); PLUS(c2,d2); XOR(b1,c1); XOR(b2,c2);	\
+	    ROTATE2(b1, b2, 12, tmp1, tmp2);			\
+	PLUS(a1,b1); PLUS(a2,b2); XOR(d1,a1); XOR(d2,a2);	\
+	    ROTATE2(d1, d2, 8, tmp1, tmp2);			\
+	PLUS(c1,d1); PLUS(c2,d2); XOR(b1,c1); XOR(b2,c2);	\
+	    ROTATE2(b1, b2,  7, tmp1, tmp2);
+
+	.section .text.sse2,"ax",@progbits
+
+chacha20_data:
+	.align 16
+L(counter1):
+	.long 1,0,0,0
+L(inc_counter):
+	.long 0,1,2,3
+L(unsigned_cmp):
+	.long 0x80000000,0x80000000,0x80000000,0x80000000
+
+	.hidden __chacha20_sse2_blocks4
+ENTRY (__chacha20_sse2_blocks4)
+	/* input:
+	 *	%rdi: input
+	 *	%rsi: dst
+	 *	%rdx: src
+	 *	%rcx: nblks (multiple of 4)
+	 */
+
+	pushq %rbp;
+	cfi_adjust_cfa_offset(8);
+	cfi_rel_offset(rbp, 0)
+	movq %rsp, %rbp;
+	cfi_def_cfa_register(%rbp);
+
+	subq $STACK_MAX, %rsp;
+	andq $~15, %rsp;
+
+L(loop4):
+	mov $20, ROUND;
+
+	/* Construct counter vectors X12 and X13 */
+	movdqa L(inc_counter) rRIP, X0;
+	movdqa L(unsigned_cmp) rRIP, X2;
+	PBROADCASTD((12 * 4)(INPUT), X12);
+	PBROADCASTD((13 * 4)(INPUT), X13);
+	paddd X0, X12;
+	movdqa X12, X1;
+	pxor X2, X0;
+	pxor X2, X1;
+	pcmpgtd X1, X0;
+	psubd X0, X13;
+	movdqa X12, (STACK_VEC_X12)(%rsp);
+	movdqa X13, (STACK_VEC_X13)(%rsp);
+
+	/* Load vectors */
+	PBROADCASTD((0 * 4)(INPUT), X0);
+	PBROADCASTD((1 * 4)(INPUT), X1);
+	PBROADCASTD((2 * 4)(INPUT), X2);
+	PBROADCASTD((3 * 4)(INPUT), X3);
+	PBROADCASTD((4 * 4)(INPUT), X4);
+	PBROADCASTD((5 * 4)(INPUT), X5);
+	PBROADCASTD((6 * 4)(INPUT), X6);
+	PBROADCASTD((7 * 4)(INPUT), X7);
+	PBROADCASTD((8 * 4)(INPUT), X8);
+	PBROADCASTD((9 * 4)(INPUT), X9);
+	PBROADCASTD((10 * 4)(INPUT), X10);
+	PBROADCASTD((11 * 4)(INPUT), X11);
+	PBROADCASTD((14 * 4)(INPUT), X14);
+	PBROADCASTD((15 * 4)(INPUT), X15);
+	movdqa X11, (STACK_TMP)(%rsp);
+	movdqa X15, (STACK_TMP1)(%rsp);
+
+L(round2_4):
+	QUARTERROUND2(X0, X4,  X8, X12,   X1, X5,  X9, X13, tmp:=,X11,X15)
+	movdqa (STACK_TMP)(%rsp), X11;
+	movdqa (STACK_TMP1)(%rsp), X15;
+	movdqa X8, (STACK_TMP)(%rsp);
+	movdqa X9, (STACK_TMP1)(%rsp);
+	QUARTERROUND2(X2, X6, X10, X14,   X3, X7, X11, X15, tmp:=,X8,X9)
+	QUARTERROUND2(X0, X5, X10, X15,   X1, X6, X11, X12, tmp:=,X8,X9)
+	movdqa (STACK_TMP)(%rsp), X8;
+	movdqa (STACK_TMP1)(%rsp), X9;
+	movdqa X11, (STACK_TMP)(%rsp);
+	movdqa X15, (STACK_TMP1)(%rsp);
+	QUARTERROUND2(X2, X7,  X8, X13,   X3, X4,  X9, X14, tmp:=,X11,X15)
+	sub $2, ROUND;
+	jnz L(round2_4);
+
+	/* tmp := X15 */
+	movdqa (STACK_TMP)(%rsp), X11;
+	PBROADCASTD((0 * 4)(INPUT), X15);
+	PLUS(X0, X15);
+	PBROADCASTD((1 * 4)(INPUT), X15);
+	PLUS(X1, X15);
+	PBROADCASTD((2 * 4)(INPUT), X15);
+	PLUS(X2, X15);
+	PBROADCASTD((3 * 4)(INPUT), X15);
+	PLUS(X3, X15);
+	PBROADCASTD((4 * 4)(INPUT), X15);
+	PLUS(X4, X15);
+	PBROADCASTD((5 * 4)(INPUT), X15);
+	PLUS(X5, X15);
+	PBROADCASTD((6 * 4)(INPUT), X15);
+	PLUS(X6, X15);
+	PBROADCASTD((7 * 4)(INPUT), X15);
+	PLUS(X7, X15);
+	PBROADCASTD((8 * 4)(INPUT), X15);
+	PLUS(X8, X15);
+	PBROADCASTD((9 * 4)(INPUT), X15);
+	PLUS(X9, X15);
+	PBROADCASTD((10 * 4)(INPUT), X15);
+	PLUS(X10, X15);
+	PBROADCASTD((11 * 4)(INPUT), X15);
+	PLUS(X11, X15);
+	movdqa (STACK_VEC_X12)(%rsp), X15;
+	PLUS(X12, X15);
+	movdqa (STACK_VEC_X13)(%rsp), X15;
+	PLUS(X13, X15);
+	movdqa X13, (STACK_TMP)(%rsp);
+	PBROADCASTD((14 * 4)(INPUT), X15);
+	PLUS(X14, X15);
+	movdqa (STACK_TMP1)(%rsp), X15;
+	movdqa X14, (STACK_TMP1)(%rsp);
+	PBROADCASTD((15 * 4)(INPUT), X13);
+	PLUS(X15, X13);
+	movdqa X15, (STACK_TMP2)(%rsp);
+
+	/* Update counter */
+	addq $4, (12 * 4)(INPUT);
+
+	TRANSPOSE_4x4(X0, X1, X2, X3, X13, X14, X15);
+	movdqu X0, (64 * 0 + 16 * 0)(DST)
+	movdqu X1, (64 * 1 + 16 * 0)(DST)
+	movdqu X2, (64 * 2 + 16 * 0)(DST)
+	movdqu X3, (64 * 3 + 16 * 0)(DST)
+	TRANSPOSE_4x4(X4, X5, X6, X7, X0, X1, X2);
+	movdqa (STACK_TMP)(%rsp), X13;
+	movdqa (STACK_TMP1)(%rsp), X14;
+	movdqa (STACK_TMP2)(%rsp), X15;
+	movdqu X4, (64 * 0 + 16 * 1)(DST)
+	movdqu X5, (64 * 1 + 16 * 1)(DST)
+	movdqu X6, (64 * 2 + 16 * 1)(DST)
+	movdqu X7, (64 * 3 + 16 * 1)(DST)
+	TRANSPOSE_4x4(X8, X9, X10, X11, X0, X1, X2);
+	movdqu X8,  (64 * 0 + 16 * 2)(DST)
+	movdqu X9,  (64 * 1 + 16 * 2)(DST)
+	movdqu X10, (64 * 2 + 16 * 2)(DST)
+	movdqu X11, (64 * 3 + 16 * 2)(DST)
+	TRANSPOSE_4x4(X12, X13, X14, X15, X0, X1, X2);
+	movdqu X12, (64 * 0 + 16 * 3)(DST)
+	movdqu X13, (64 * 1 + 16 * 3)(DST)
+	movdqu X14, (64 * 2 + 16 * 3)(DST)
+	movdqu X15, (64 * 3 + 16 * 3)(DST)
+
+	sub $4, NBLKS;
+	lea (4 * 64)(DST), DST;
+	lea (4 * 64)(SRC), SRC;
+	jnz L(loop4);
+
+	/* eax zeroed by round loop. */
+	leave;
+	cfi_adjust_cfa_offset(-8)
+	cfi_def_cfa_register(%rsp);
+	ret_spec_stop;
+END (__chacha20_sse2_blocks4)
diff --git a/sysdeps/x86_64/chacha20_arch.h b/sysdeps/x86_64/chacha20_arch.h
new file mode 100644
index 0000000000..908f6795d5
--- /dev/null
+++ b/sysdeps/x86_64/chacha20_arch.h
@@ -0,0 +1,37 @@
+/* Chacha20 implementation, used on arc4random.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <ldsodefs.h>
+#include <cpu-features.h>
+#include <sys/param.h>
+
+unsigned int __chacha20_sse2_blocks4 (uint32_t *state, uint8_t *dst,
+				      const uint8_t *src, size_t nblks)
+     attribute_hidden;
+
+static inline void
+chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
+{
+  _Static_assert (CHACHA20_BUFSIZE % 4 == 0,
+		  "CHACHA20_BUFSIZE not multiple of 4");
+  _Static_assert (CHACHA20_BUFSIZE >= CHACHA20_BLOCK_SIZE * 4,
+		  "CHACHA20_BUFSIZE <= CHACHA20_BLOCK_SIZE * 4");
+
+  __chacha20_sse2_blocks4 (state, dst, src,
+			   CHACHA20_BUFSIZE / CHACHA20_BLOCK_SIZE);
+}
-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH v12 6/9] x86: Add AVX2 optimized chacha20
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
                   ` (4 preceding siblings ...)
  2022-07-22 12:21 ` [PATCH v12 5/9] x86: Add SSE2 " Adhemerval Zanella
@ 2022-07-22 12:21 ` Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 7/9] powerpc64: Add " Adhemerval Zanella
                   ` (3 subsequent siblings)
  9 siblings, 0 replies; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

It adds vectorized ChaCha20 implementation based on libgcrypt
cipher/chacha20-amd64-avx2.S.  It is used only if AVX2 is supported
and enabled by the architecture.

As for generic implementation, the last step that XOR with the
input is omited.  The final state register clearing is also
omitted.

On a Ryzen 9 5900X it shows the following improvements (using
formatted bench-arc4random data):

SSE                                        MB/s
-----------------------------------------------
arc4random [single-thread]               704.25
arc4random_buf(16) [single-thread]      1018.17
arc4random_buf(32) [single-thread]      1315.27
arc4random_buf(48) [single-thread]      1449.36
arc4random_buf(64) [single-thread]      1511.16
arc4random_buf(80) [single-thread]      1539.48
arc4random_buf(96) [single-thread]      1571.06
arc4random_buf(112) [single-thread]     1596.16
arc4random_buf(128) [single-thread]     1613.48
-----------------------------------------------

AVX2                                       MB/s
-----------------------------------------------
arc4random [single-thread]               922.61
arc4random_buf(16) [single-thread]      1478.70
arc4random_buf(32) [single-thread]      2241.80
arc4random_buf(48) [single-thread]      2681.28
arc4random_buf(64) [single-thread]      2913.43
arc4random_buf(80) [single-thread]      3009.73
arc4random_buf(96) [single-thread]      3141.16
arc4random_buf(112) [single-thread]     3254.46
arc4random_buf(128) [single-thread]     3305.02
-----------------------------------------------

Checked on x86_64-linux-gnu.
---
 LICENSES                             |   5 +-
 sysdeps/x86_64/Makefile              |   1 +
 sysdeps/x86_64/chacha20-amd64-avx2.S | 328 +++++++++++++++++++++++++++
 sysdeps/x86_64/chacha20-amd64-sse2.S |   5 +
 sysdeps/x86_64/chacha20_arch.h       |  27 ++-
 5 files changed, 359 insertions(+), 7 deletions(-)
 create mode 100644 sysdeps/x86_64/chacha20-amd64-avx2.S

diff --git a/LICENSES b/LICENSES
index f0117ef79f..80168d0b1b 100644
--- a/LICENSES
+++ b/LICENSES
@@ -390,8 +390,9 @@ Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>
  License along with this library; if not, see
  <https://www.gnu.org/licenses/>.  */
 \f
-sysdeps/aarch64/chacha20-aarch64.S and sysdeps/x86_64/chacha20-amd64-sse2.S
-imports code from libgcrypt, with the following notices:
+sysdeps/aarch64/chacha20-aarch64.S, sysdeps/x86_64/chacha20-amd64-sse2.S,
+and sysdeps/x86_64/chacha20-amd64-avx2.S imports code from libgcrypt,
+with the following notices:
 
 Copyright (C) 2017-2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
 
diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
index 3acd9755a5..1178475d75 100644
--- a/sysdeps/x86_64/Makefile
+++ b/sysdeps/x86_64/Makefile
@@ -8,6 +8,7 @@ endif
 ifeq ($(subdir),stdlib)
 sysdep_routines += \
   chacha20-amd64-sse2 \
+  chacha20-amd64-avx2 \
   # sysdep_routines
 endif
 
diff --git a/sysdeps/x86_64/chacha20-amd64-avx2.S b/sysdeps/x86_64/chacha20-amd64-avx2.S
new file mode 100644
index 0000000000..aefd1cdbd0
--- /dev/null
+++ b/sysdeps/x86_64/chacha20-amd64-avx2.S
@@ -0,0 +1,328 @@
+/* Optimized AVX2 implementation of ChaCha20 cipher.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* chacha20-amd64-avx2.S  -  AVX2 implementation of ChaCha20 cipher
+
+   Copyright (C) 2017-2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+
+   This file is part of Libgcrypt.
+
+   Libgcrypt is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of
+   the License, or (at your option) any later version.
+
+   Libgcrypt is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, see <https://www.gnu.org/licenses/>.
+*/
+
+/* Based on D. J. Bernstein reference implementation at
+   http://cr.yp.to/chacha.html:
+
+   chacha-regs.c version 20080118
+   D. J. Bernstein
+   Public domain.  */
+
+#include <sysdep.h>
+
+#ifdef PIC
+#  define rRIP (%rip)
+#else
+#  define rRIP
+#endif
+
+/* register macros */
+#define INPUT %rdi
+#define DST   %rsi
+#define SRC   %rdx
+#define NBLKS %rcx
+#define ROUND %eax
+
+/* stack structure */
+#define STACK_VEC_X12 (32)
+#define STACK_VEC_X13 (32 + STACK_VEC_X12)
+#define STACK_TMP     (32 + STACK_VEC_X13)
+#define STACK_TMP1    (32 + STACK_TMP)
+
+#define STACK_MAX     (32 + STACK_TMP1)
+
+/* vector registers */
+#define X0 %ymm0
+#define X1 %ymm1
+#define X2 %ymm2
+#define X3 %ymm3
+#define X4 %ymm4
+#define X5 %ymm5
+#define X6 %ymm6
+#define X7 %ymm7
+#define X8 %ymm8
+#define X9 %ymm9
+#define X10 %ymm10
+#define X11 %ymm11
+#define X12 %ymm12
+#define X13 %ymm13
+#define X14 %ymm14
+#define X15 %ymm15
+
+#define X0h %xmm0
+#define X1h %xmm1
+#define X2h %xmm2
+#define X3h %xmm3
+#define X4h %xmm4
+#define X5h %xmm5
+#define X6h %xmm6
+#define X7h %xmm7
+#define X8h %xmm8
+#define X9h %xmm9
+#define X10h %xmm10
+#define X11h %xmm11
+#define X12h %xmm12
+#define X13h %xmm13
+#define X14h %xmm14
+#define X15h %xmm15
+
+/**********************************************************************
+  helper macros
+ **********************************************************************/
+
+/* 4x4 32-bit integer matrix transpose */
+#define transpose_4x4(x0,x1,x2,x3,t1,t2) \
+	vpunpckhdq x1, x0, t2; \
+	vpunpckldq x1, x0, x0; \
+	\
+	vpunpckldq x3, x2, t1; \
+	vpunpckhdq x3, x2, x2; \
+	\
+	vpunpckhqdq t1, x0, x1; \
+	vpunpcklqdq t1, x0, x0; \
+	\
+	vpunpckhqdq x2, t2, x3; \
+	vpunpcklqdq x2, t2, x2;
+
+/* 2x2 128-bit matrix transpose */
+#define transpose_16byte_2x2(x0,x1,t1) \
+	vmovdqa    x0, t1; \
+	vperm2i128 $0x20, x1, x0, x0; \
+	vperm2i128 $0x31, x1, t1, x1;
+
+/**********************************************************************
+  8-way chacha20
+ **********************************************************************/
+
+#define ROTATE2(v1,v2,c,tmp)	\
+	vpsrld $(32 - (c)), v1, tmp;	\
+	vpslld $(c), v1, v1;		\
+	vpaddb tmp, v1, v1;		\
+	vpsrld $(32 - (c)), v2, tmp;	\
+	vpslld $(c), v2, v2;		\
+	vpaddb tmp, v2, v2;
+
+#define ROTATE_SHUF_2(v1,v2,shuf)	\
+	vpshufb shuf, v1, v1;		\
+	vpshufb shuf, v2, v2;
+
+#define XOR(ds,s) \
+	vpxor s, ds, ds;
+
+#define PLUS(ds,s) \
+	vpaddd s, ds, ds;
+
+#define QUARTERROUND2(a1,b1,c1,d1,a2,b2,c2,d2,ign,tmp1,\
+		      interleave_op1,interleave_op2,\
+		      interleave_op3,interleave_op4)		\
+	vbroadcasti128 .Lshuf_rol16 rRIP, tmp1;			\
+		interleave_op1;					\
+	PLUS(a1,b1); PLUS(a2,b2); XOR(d1,a1); XOR(d2,a2);	\
+	    ROTATE_SHUF_2(d1, d2, tmp1);			\
+		interleave_op2;					\
+	PLUS(c1,d1); PLUS(c2,d2); XOR(b1,c1); XOR(b2,c2);	\
+	    ROTATE2(b1, b2, 12, tmp1);				\
+	vbroadcasti128 .Lshuf_rol8 rRIP, tmp1;			\
+		interleave_op3;					\
+	PLUS(a1,b1); PLUS(a2,b2); XOR(d1,a1); XOR(d2,a2);	\
+	    ROTATE_SHUF_2(d1, d2, tmp1);			\
+		interleave_op4;					\
+	PLUS(c1,d1); PLUS(c2,d2); XOR(b1,c1); XOR(b2,c2);	\
+	    ROTATE2(b1, b2,  7, tmp1);
+
+	.section .text.avx2, "ax", @progbits
+	.align 32
+chacha20_data:
+L(shuf_rol16):
+	.byte 2,3,0,1,6,7,4,5,10,11,8,9,14,15,12,13
+L(shuf_rol8):
+	.byte 3,0,1,2,7,4,5,6,11,8,9,10,15,12,13,14
+L(inc_counter):
+	.byte 0,1,2,3,4,5,6,7
+L(unsigned_cmp):
+	.long 0x80000000
+
+	.hidden __chacha20_avx2_blocks8
+ENTRY (__chacha20_avx2_blocks8)
+	/* input:
+	 *	%rdi: input
+	 *	%rsi: dst
+	 *	%rdx: src
+	 *	%rcx: nblks (multiple of 8)
+	 */
+	vzeroupper;
+
+	pushq %rbp;
+	cfi_adjust_cfa_offset(8);
+	cfi_rel_offset(rbp, 0)
+	movq %rsp, %rbp;
+	cfi_def_cfa_register(rbp);
+
+	subq $STACK_MAX, %rsp;
+	andq $~31, %rsp;
+
+L(loop8):
+	mov $20, ROUND;
+
+	/* Construct counter vectors X12 and X13 */
+	vpmovzxbd L(inc_counter) rRIP, X0;
+	vpbroadcastd L(unsigned_cmp) rRIP, X2;
+	vpbroadcastd (12 * 4)(INPUT), X12;
+	vpbroadcastd (13 * 4)(INPUT), X13;
+	vpaddd X0, X12, X12;
+	vpxor X2, X0, X0;
+	vpxor X2, X12, X1;
+	vpcmpgtd X1, X0, X0;
+	vpsubd X0, X13, X13;
+	vmovdqa X12, (STACK_VEC_X12)(%rsp);
+	vmovdqa X13, (STACK_VEC_X13)(%rsp);
+
+	/* Load vectors */
+	vpbroadcastd (0 * 4)(INPUT), X0;
+	vpbroadcastd (1 * 4)(INPUT), X1;
+	vpbroadcastd (2 * 4)(INPUT), X2;
+	vpbroadcastd (3 * 4)(INPUT), X3;
+	vpbroadcastd (4 * 4)(INPUT), X4;
+	vpbroadcastd (5 * 4)(INPUT), X5;
+	vpbroadcastd (6 * 4)(INPUT), X6;
+	vpbroadcastd (7 * 4)(INPUT), X7;
+	vpbroadcastd (8 * 4)(INPUT), X8;
+	vpbroadcastd (9 * 4)(INPUT), X9;
+	vpbroadcastd (10 * 4)(INPUT), X10;
+	vpbroadcastd (11 * 4)(INPUT), X11;
+	vpbroadcastd (14 * 4)(INPUT), X14;
+	vpbroadcastd (15 * 4)(INPUT), X15;
+	vmovdqa X15, (STACK_TMP)(%rsp);
+
+L(round2):
+	QUARTERROUND2(X0, X4,  X8, X12,   X1, X5,  X9, X13, tmp:=,X15,,,,)
+	vmovdqa (STACK_TMP)(%rsp), X15;
+	vmovdqa X8, (STACK_TMP)(%rsp);
+	QUARTERROUND2(X2, X6, X10, X14,   X3, X7, X11, X15, tmp:=,X8,,,,)
+	QUARTERROUND2(X0, X5, X10, X15,   X1, X6, X11, X12, tmp:=,X8,,,,)
+	vmovdqa (STACK_TMP)(%rsp), X8;
+	vmovdqa X15, (STACK_TMP)(%rsp);
+	QUARTERROUND2(X2, X7,  X8, X13,   X3, X4,  X9, X14, tmp:=,X15,,,,)
+	sub $2, ROUND;
+	jnz L(round2);
+
+	vmovdqa X8, (STACK_TMP1)(%rsp);
+
+	/* tmp := X15 */
+	vpbroadcastd (0 * 4)(INPUT), X15;
+	PLUS(X0, X15);
+	vpbroadcastd (1 * 4)(INPUT), X15;
+	PLUS(X1, X15);
+	vpbroadcastd (2 * 4)(INPUT), X15;
+	PLUS(X2, X15);
+	vpbroadcastd (3 * 4)(INPUT), X15;
+	PLUS(X3, X15);
+	vpbroadcastd (4 * 4)(INPUT), X15;
+	PLUS(X4, X15);
+	vpbroadcastd (5 * 4)(INPUT), X15;
+	PLUS(X5, X15);
+	vpbroadcastd (6 * 4)(INPUT), X15;
+	PLUS(X6, X15);
+	vpbroadcastd (7 * 4)(INPUT), X15;
+	PLUS(X7, X15);
+	transpose_4x4(X0, X1, X2, X3, X8, X15);
+	transpose_4x4(X4, X5, X6, X7, X8, X15);
+	vmovdqa (STACK_TMP1)(%rsp), X8;
+	transpose_16byte_2x2(X0, X4, X15);
+	transpose_16byte_2x2(X1, X5, X15);
+	transpose_16byte_2x2(X2, X6, X15);
+	transpose_16byte_2x2(X3, X7, X15);
+	vmovdqa (STACK_TMP)(%rsp), X15;
+	vmovdqu X0, (64 * 0 + 16 * 0)(DST)
+	vmovdqu X1, (64 * 1 + 16 * 0)(DST)
+	vpbroadcastd (8 * 4)(INPUT), X0;
+	PLUS(X8, X0);
+	vpbroadcastd (9 * 4)(INPUT), X0;
+	PLUS(X9, X0);
+	vpbroadcastd (10 * 4)(INPUT), X0;
+	PLUS(X10, X0);
+	vpbroadcastd (11 * 4)(INPUT), X0;
+	PLUS(X11, X0);
+	vmovdqa (STACK_VEC_X12)(%rsp), X0;
+	PLUS(X12, X0);
+	vmovdqa (STACK_VEC_X13)(%rsp), X0;
+	PLUS(X13, X0);
+	vpbroadcastd (14 * 4)(INPUT), X0;
+	PLUS(X14, X0);
+	vpbroadcastd (15 * 4)(INPUT), X0;
+	PLUS(X15, X0);
+	vmovdqu X2, (64 * 2 + 16 * 0)(DST)
+	vmovdqu X3, (64 * 3 + 16 * 0)(DST)
+
+	/* Update counter */
+	addq $8, (12 * 4)(INPUT);
+
+	transpose_4x4(X8, X9, X10, X11, X0, X1);
+	transpose_4x4(X12, X13, X14, X15, X0, X1);
+	vmovdqu X4, (64 * 4 + 16 * 0)(DST)
+	vmovdqu X5, (64 * 5 + 16 * 0)(DST)
+	transpose_16byte_2x2(X8, X12, X0);
+	transpose_16byte_2x2(X9, X13, X0);
+	transpose_16byte_2x2(X10, X14, X0);
+	transpose_16byte_2x2(X11, X15, X0);
+	vmovdqu X6,  (64 * 6 + 16 * 0)(DST)
+	vmovdqu X7,  (64 * 7 + 16 * 0)(DST)
+	vmovdqu X8,  (64 * 0 + 16 * 2)(DST)
+	vmovdqu X9,  (64 * 1 + 16 * 2)(DST)
+	vmovdqu X10, (64 * 2 + 16 * 2)(DST)
+	vmovdqu X11, (64 * 3 + 16 * 2)(DST)
+	vmovdqu X12, (64 * 4 + 16 * 2)(DST)
+	vmovdqu X13, (64 * 5 + 16 * 2)(DST)
+	vmovdqu X14, (64 * 6 + 16 * 2)(DST)
+	vmovdqu X15, (64 * 7 + 16 * 2)(DST)
+
+	sub $8, NBLKS;
+	lea (8 * 64)(DST), DST;
+	lea (8 * 64)(SRC), SRC;
+	jnz L(loop8);
+
+	vzeroupper;
+
+	/* eax zeroed by round loop. */
+	leave;
+	cfi_adjust_cfa_offset(-8)
+	cfi_def_cfa_register(%rsp);
+	ret;
+	int3;
+END(__chacha20_avx2_blocks8)
diff --git a/sysdeps/x86_64/chacha20-amd64-sse2.S b/sysdeps/x86_64/chacha20-amd64-sse2.S
index 1178f06306..351a1109c6 100644
--- a/sysdeps/x86_64/chacha20-amd64-sse2.S
+++ b/sysdeps/x86_64/chacha20-amd64-sse2.S
@@ -44,6 +44,9 @@
    Public domain.  */
 
 #include <sysdep.h>
+#include <isa-level.h>
+
+#if MINIMUM_X86_ISA_LEVEL <= 2
 
 #ifdef PIC
 #  define rRIP (%rip)
@@ -304,3 +307,5 @@ L(round2_4):
 	cfi_def_cfa_register(%rsp);
 	ret_spec_stop;
 END (__chacha20_sse2_blocks4)
+
+#endif /* if MINIMUM_X86_ISA_LEVEL <= 2 */
diff --git a/sysdeps/x86_64/chacha20_arch.h b/sysdeps/x86_64/chacha20_arch.h
index 908f6795d5..c1e33c91b3 100644
--- a/sysdeps/x86_64/chacha20_arch.h
+++ b/sysdeps/x86_64/chacha20_arch.h
@@ -16,6 +16,7 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <isa-level.h>
 #include <ldsodefs.h>
 #include <cpu-features.h>
 #include <sys/param.h>
@@ -23,15 +24,31 @@
 unsigned int __chacha20_sse2_blocks4 (uint32_t *state, uint8_t *dst,
 				      const uint8_t *src, size_t nblks)
      attribute_hidden;
+unsigned int __chacha20_avx2_blocks8 (uint32_t *state, uint8_t *dst,
+				      const uint8_t *src, size_t nblks)
+     attribute_hidden;
 
 static inline void
 chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
 {
-  _Static_assert (CHACHA20_BUFSIZE % 4 == 0,
-		  "CHACHA20_BUFSIZE not multiple of 4");
-  _Static_assert (CHACHA20_BUFSIZE >= CHACHA20_BLOCK_SIZE * 4,
-		  "CHACHA20_BUFSIZE <= CHACHA20_BLOCK_SIZE * 4");
+  _Static_assert (CHACHA20_BUFSIZE % 4 == 0 && CHACHA20_BUFSIZE % 8 == 0,
+		  "CHACHA20_BUFSIZE not multiple of 4 or 8");
+  _Static_assert (CHACHA20_BUFSIZE >= CHACHA20_BLOCK_SIZE * 8,
+		  "CHACHA20_BUFSIZE < CHACHA20_BLOCK_SIZE * 8");
 
-  __chacha20_sse2_blocks4 (state, dst, src,
+#if MINIMUM_X86_ISA_LEVEL > 2
+  __chacha20_avx2_blocks8 (state, dst, src,
 			   CHACHA20_BUFSIZE / CHACHA20_BLOCK_SIZE);
+#else
+  const struct cpu_features* cpu_features = __get_cpu_features ();
+
+  /* AVX2 version uses vzeroupper, so disable it if RTM is enabled.  */
+  if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2)
+      && X86_ISA_CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER, !))
+    __chacha20_avx2_blocks8 (state, dst, src,
+			     CHACHA20_BUFSIZE / CHACHA20_BLOCK_SIZE);
+  else
+    __chacha20_sse2_blocks4 (state, dst, src,
+			     CHACHA20_BUFSIZE / CHACHA20_BLOCK_SIZE);
+#endif
 }
-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH v12 7/9] powerpc64: Add optimized chacha20
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
                   ` (5 preceding siblings ...)
  2022-07-22 12:21 ` [PATCH v12 6/9] x86: Add AVX2 " Adhemerval Zanella
@ 2022-07-22 12:21 ` Adhemerval Zanella
  2022-07-27 14:09   ` Tulio Magno Quites Machado Filho
  2022-07-22 12:21 ` [PATCH v12 8/9] s390x: " Adhemerval Zanella
                   ` (2 subsequent siblings)
  9 siblings, 1 reply; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy
  Cc: Adhemerval Zanella Netto, Paul E . Murphy

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

It adds vectorized ChaCha20 implementation based on libgcrypt
cipher/chacha20-ppc.c.  It targets POWER8 and it is used on default
for LE.

On a POWER8 it shows the following improvements (using formatted
bench-arc4random data):

POWER8

GENERIC                                    MB/s
-----------------------------------------------
arc4random [single-thread]               138.77
arc4random_buf(16) [single-thread]       174.36
arc4random_buf(32) [single-thread]       228.11
arc4random_buf(48) [single-thread]       252.31
arc4random_buf(64) [single-thread]       270.11
arc4random_buf(80) [single-thread]       278.97
arc4random_buf(96) [single-thread]       287.78
arc4random_buf(112) [single-thread]      291.92
arc4random_buf(128) [single-thread]      295.25

POWER8                                     MB/s
-----------------------------------------------
arc4random [single-thread]               198.06
arc4random_buf(16) [single-thread]       278.79
arc4random_buf(32) [single-thread]       448.89
arc4random_buf(48) [single-thread]       551.09
arc4random_buf(64) [single-thread]       646.12
arc4random_buf(80) [single-thread]       698.04
arc4random_buf(96) [single-thread]       756.06
arc4random_buf(112) [single-thread]      784.12
arc4random_buf(128) [single-thread]      808.04
-----------------------------------------------

Checked on powerpc64-linux-gnu and powerpc64le-linux-gnu.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
---
 LICENSES                                      |   3 +-
 .../powerpc/powerpc64/be/multiarch/Makefile   |   4 +
 .../powerpc64/be/multiarch/chacha20-ppc.c     |   1 +
 .../powerpc64/be/multiarch/chacha20_arch.h    |  41 +++
 sysdeps/powerpc/powerpc64/power8/Makefile     |   5 +
 .../powerpc/powerpc64/power8/chacha20-ppc.c   | 256 ++++++++++++++++++
 .../powerpc/powerpc64/power8/chacha20_arch.h  |  36 +++
 7 files changed, 345 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/powerpc/powerpc64/be/multiarch/Makefile
 create mode 100644 sysdeps/powerpc/powerpc64/be/multiarch/chacha20-ppc.c
 create mode 100644 sysdeps/powerpc/powerpc64/be/multiarch/chacha20_arch.h
 create mode 100644 sysdeps/powerpc/powerpc64/power8/chacha20-ppc.c
 create mode 100644 sysdeps/powerpc/powerpc64/power8/chacha20_arch.h

diff --git a/LICENSES b/LICENSES
index 80168d0b1b..e177af6035 100644
--- a/LICENSES
+++ b/LICENSES
@@ -391,7 +391,8 @@ Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>
  <https://www.gnu.org/licenses/>.  */
 \f
 sysdeps/aarch64/chacha20-aarch64.S, sysdeps/x86_64/chacha20-amd64-sse2.S,
-and sysdeps/x86_64/chacha20-amd64-avx2.S imports code from libgcrypt,
+sysdeps/x86_64/chacha20-amd64-avx2.S, and
+sysdeps/powerpc/powerpc64/power8/chacha20-ppc.c imports code from libgcrypt,
 with the following notices:
 
 Copyright (C) 2017-2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
diff --git a/sysdeps/powerpc/powerpc64/be/multiarch/Makefile b/sysdeps/powerpc/powerpc64/be/multiarch/Makefile
new file mode 100644
index 0000000000..8c75165f7f
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/be/multiarch/Makefile
@@ -0,0 +1,4 @@
+ifeq ($(subdir),stdlib)
+sysdep_routines += chacha20-ppc
+CFLAGS-chacha20-ppc.c += -mcpu=power8
+endif
diff --git a/sysdeps/powerpc/powerpc64/be/multiarch/chacha20-ppc.c b/sysdeps/powerpc/powerpc64/be/multiarch/chacha20-ppc.c
new file mode 100644
index 0000000000..cf9e735326
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/be/multiarch/chacha20-ppc.c
@@ -0,0 +1 @@
+#include <sysdeps/powerpc/powerpc64/power8/chacha20-ppc.c>
diff --git a/sysdeps/powerpc/powerpc64/be/multiarch/chacha20_arch.h b/sysdeps/powerpc/powerpc64/be/multiarch/chacha20_arch.h
new file mode 100644
index 0000000000..c9ff8b0d27
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/be/multiarch/chacha20_arch.h
@@ -0,0 +1,41 @@
+/* PowerPC optimization for ChaCha20.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <stdbool.h>
+#include <ldsodefs.h>
+
+unsigned int __chacha20_power8_blocks4 (uint32_t *state, uint8_t *dst,
+					const uint8_t *src, size_t nblks)
+     attribute_hidden;
+
+static void
+chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
+{
+  _Static_assert (CHACHA20_BUFSIZE % 4 == 0,
+		  "CHACHA20_BUFSIZE not multiple of 4");
+  _Static_assert (CHACHA20_BUFSIZE >= CHACHA20_BLOCK_SIZE * 4,
+		  "CHACHA20_BUFSIZE < CHACHA20_BLOCK_SIZE * 4");
+
+  unsigned long int hwcap = GLRO(dl_hwcap);
+  unsigned long int hwcap2 = GLRO(dl_hwcap2);
+  if (hwcap2 & PPC_FEATURE2_ARCH_2_07 && hwcap & PPC_FEATURE_HAS_ALTIVEC)
+    __chacha20_power8_blocks4 (state, dst, src,
+			       CHACHA20_BUFSIZE / CHACHA20_BLOCK_SIZE);
+  else
+    chacha20_crypt_generic (state, dst, src);
+}
diff --git a/sysdeps/powerpc/powerpc64/power8/Makefile b/sysdeps/powerpc/powerpc64/power8/Makefile
index 71a59529f3..abb0aa3f11 100644
--- a/sysdeps/powerpc/powerpc64/power8/Makefile
+++ b/sysdeps/powerpc/powerpc64/power8/Makefile
@@ -1,3 +1,8 @@
 ifeq ($(subdir),string)
 sysdep_routines += strcasestr-ppc64
 endif
+
+ifeq ($(subdir),stdlib)
+sysdep_routines += chacha20-ppc
+CFLAGS-chacha20-ppc.c += -mcpu=power8
+endif
diff --git a/sysdeps/powerpc/powerpc64/power8/chacha20-ppc.c b/sysdeps/powerpc/powerpc64/power8/chacha20-ppc.c
new file mode 100644
index 0000000000..0bbdcb9363
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power8/chacha20-ppc.c
@@ -0,0 +1,256 @@
+/* Optimized PowerPC implementation of ChaCha20 cipher.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* chacha20-ppc.c - PowerPC vector implementation of ChaCha20
+   Copyright (C) 2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+
+   This file is part of Libgcrypt.
+
+   Libgcrypt is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of
+   the License, or (at your option) any later version.
+
+   Libgcrypt is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <altivec.h>
+#include <endian.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/cdefs.h>
+
+typedef vector unsigned char vector16x_u8;
+typedef vector unsigned int vector4x_u32;
+typedef vector unsigned long long vector2x_u64;
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+static const vector16x_u8 le_bswap_const =
+  { 3, 2, 1, 0, 7, 6, 5, 4, 11, 10, 9, 8, 15, 14, 13, 12 };
+#endif
+
+static inline vector4x_u32
+vec_rol_elems (vector4x_u32 v, unsigned int idx)
+{
+#if __BYTE_ORDER != __BIG_ENDIAN
+  return vec_sld (v, v, (16 - (4 * idx)) & 15);
+#else
+  return vec_sld (v, v, (4 * idx) & 15);
+#endif
+}
+
+static inline vector4x_u32
+vec_load_le (unsigned long offset, const unsigned char *ptr)
+{
+  vector4x_u32 vec;
+  vec = vec_vsx_ld (offset, (const uint32_t *)ptr);
+#if __BYTE_ORDER == __BIG_ENDIAN
+  vec = (vector4x_u32) vec_perm ((vector16x_u8)vec, (vector16x_u8)vec,
+				 le_bswap_const);
+#endif
+  return vec;
+}
+
+static inline void
+vec_store_le (vector4x_u32 vec, unsigned long offset, unsigned char *ptr)
+{
+#if __BYTE_ORDER == __BIG_ENDIAN
+  vec = (vector4x_u32)vec_perm((vector16x_u8)vec, (vector16x_u8)vec,
+			       le_bswap_const);
+#endif
+  vec_vsx_st (vec, offset, (uint32_t *)ptr);
+}
+
+
+static inline vector4x_u32
+vec_add_ctr_u64 (vector4x_u32 v, vector4x_u32 a)
+{
+#if __BYTE_ORDER == __BIG_ENDIAN
+  static const vector16x_u8 swap32 =
+    { 4, 5, 6, 7, 0, 1, 2, 3, 12, 13, 14, 15, 8, 9, 10, 11 };
+  vector2x_u64 vec, add, sum;
+
+  vec = (vector2x_u64)vec_perm ((vector16x_u8)v, (vector16x_u8)v, swap32);
+  add = (vector2x_u64)vec_perm ((vector16x_u8)a, (vector16x_u8)a, swap32);
+  sum = vec + add;
+  return (vector4x_u32)vec_perm ((vector16x_u8)sum, (vector16x_u8)sum, swap32);
+#else
+  return (vector4x_u32)((vector2x_u64)(v) + (vector2x_u64)(a));
+#endif
+}
+
+/**********************************************************************
+  4-way chacha20
+ **********************************************************************/
+
+#define ROTATE(v1,rolv)			\
+	__asm__ ("vrlw %0,%1,%2\n\t" : "=v" (v1) : "v" (v1), "v" (rolv))
+
+#define PLUS(ds,s) \
+	((ds) += (s))
+
+#define XOR(ds,s) \
+	((ds) ^= (s))
+
+#define ADD_U64(v,a) \
+	(v = vec_add_ctr_u64(v, a))
+
+/* 4x4 32-bit integer matrix transpose */
+#define transpose_4x4(x0, x1, x2, x3) ({ \
+	vector4x_u32 t1 = vec_mergeh(x0, x2); \
+	vector4x_u32 t2 = vec_mergel(x0, x2); \
+	vector4x_u32 t3 = vec_mergeh(x1, x3); \
+	x3 = vec_mergel(x1, x3); \
+	x0 = vec_mergeh(t1, t3); \
+	x1 = vec_mergel(t1, t3); \
+	x2 = vec_mergeh(t2, x3); \
+	x3 = vec_mergel(t2, x3); \
+      })
+
+#define QUARTERROUND2(a1,b1,c1,d1,a2,b2,c2,d2)			\
+	PLUS(a1,b1); PLUS(a2,b2); XOR(d1,a1); XOR(d2,a2);	\
+	    ROTATE(d1, rotate_16); ROTATE(d2, rotate_16);	\
+	PLUS(c1,d1); PLUS(c2,d2); XOR(b1,c1); XOR(b2,c2);	\
+	    ROTATE(b1, rotate_12); ROTATE(b2, rotate_12);	\
+	PLUS(a1,b1); PLUS(a2,b2); XOR(d1,a1); XOR(d2,a2);	\
+	    ROTATE(d1, rotate_8); ROTATE(d2, rotate_8);		\
+	PLUS(c1,d1); PLUS(c2,d2); XOR(b1,c1); XOR(b2,c2);	\
+	    ROTATE(b1, rotate_7); ROTATE(b2, rotate_7);
+
+unsigned int attribute_hidden
+__chacha20_power8_blocks4 (uint32_t *state, uint8_t *dst, const uint8_t *src,
+			   size_t nblks)
+{
+  vector4x_u32 counters_0123 = { 0, 1, 2, 3 };
+  vector4x_u32 counter_4 = { 4, 0, 0, 0 };
+  vector4x_u32 rotate_16 = { 16, 16, 16, 16 };
+  vector4x_u32 rotate_12 = { 12, 12, 12, 12 };
+  vector4x_u32 rotate_8 = { 8, 8, 8, 8 };
+  vector4x_u32 rotate_7 = { 7, 7, 7, 7 };
+  vector4x_u32 state0, state1, state2, state3;
+  vector4x_u32 v0, v1, v2, v3, v4, v5, v6, v7;
+  vector4x_u32 v8, v9, v10, v11, v12, v13, v14, v15;
+  vector4x_u32 tmp;
+  int i;
+
+  /* Force preload of constants to vector registers.  */
+  __asm__ ("": "+v" (counters_0123) :: "memory");
+  __asm__ ("": "+v" (counter_4) :: "memory");
+  __asm__ ("": "+v" (rotate_16) :: "memory");
+  __asm__ ("": "+v" (rotate_12) :: "memory");
+  __asm__ ("": "+v" (rotate_8) :: "memory");
+  __asm__ ("": "+v" (rotate_7) :: "memory");
+
+  state0 = vec_vsx_ld (0 * 16, state);
+  state1 = vec_vsx_ld (1 * 16, state);
+  state2 = vec_vsx_ld (2 * 16, state);
+  state3 = vec_vsx_ld (3 * 16, state);
+
+  do
+    {
+      v0 = vec_splat (state0, 0);
+      v1 = vec_splat (state0, 1);
+      v2 = vec_splat (state0, 2);
+      v3 = vec_splat (state0, 3);
+      v4 = vec_splat (state1, 0);
+      v5 = vec_splat (state1, 1);
+      v6 = vec_splat (state1, 2);
+      v7 = vec_splat (state1, 3);
+      v8 = vec_splat (state2, 0);
+      v9 = vec_splat (state2, 1);
+      v10 = vec_splat (state2, 2);
+      v11 = vec_splat (state2, 3);
+      v12 = vec_splat (state3, 0);
+      v13 = vec_splat (state3, 1);
+      v14 = vec_splat (state3, 2);
+      v15 = vec_splat (state3, 3);
+
+      v12 += counters_0123;
+      v13 -= vec_cmplt (v12, counters_0123);
+
+      for (i = 20; i > 0; i -= 2)
+	{
+	  QUARTERROUND2 (v0, v4,  v8, v12,   v1, v5,  v9, v13)
+	  QUARTERROUND2 (v2, v6, v10, v14,   v3, v7, v11, v15)
+	  QUARTERROUND2 (v0, v5, v10, v15,   v1, v6, v11, v12)
+	  QUARTERROUND2 (v2, v7,  v8, v13,   v3, v4,  v9, v14)
+	}
+
+      v0 += vec_splat (state0, 0);
+      v1 += vec_splat (state0, 1);
+      v2 += vec_splat (state0, 2);
+      v3 += vec_splat (state0, 3);
+      v4 += vec_splat (state1, 0);
+      v5 += vec_splat (state1, 1);
+      v6 += vec_splat (state1, 2);
+      v7 += vec_splat (state1, 3);
+      v8 += vec_splat (state2, 0);
+      v9 += vec_splat (state2, 1);
+      v10 += vec_splat (state2, 2);
+      v11 += vec_splat (state2, 3);
+      tmp = vec_splat( state3, 0);
+      tmp += counters_0123;
+      v12 += tmp;
+      v13 += vec_splat (state3, 1) - vec_cmplt (tmp, counters_0123);
+      v14 += vec_splat (state3, 2);
+      v15 += vec_splat (state3, 3);
+      ADD_U64 (state3, counter_4);
+
+      transpose_4x4 (v0, v1, v2, v3);
+      transpose_4x4 (v4, v5, v6, v7);
+      transpose_4x4 (v8, v9, v10, v11);
+      transpose_4x4 (v12, v13, v14, v15);
+
+      vec_store_le (v0, (64 * 0 + 16 * 0), dst);
+      vec_store_le (v1, (64 * 1 + 16 * 0), dst);
+      vec_store_le (v2, (64 * 2 + 16 * 0), dst);
+      vec_store_le (v3, (64 * 3 + 16 * 0), dst);
+
+      vec_store_le (v4, (64 * 0 + 16 * 1), dst);
+      vec_store_le (v5, (64 * 1 + 16 * 1), dst);
+      vec_store_le (v6, (64 * 2 + 16 * 1), dst);
+      vec_store_le (v7, (64 * 3 + 16 * 1), dst);
+
+      vec_store_le (v8, (64 * 0 + 16 * 2), dst);
+      vec_store_le (v9, (64 * 1 + 16 * 2), dst);
+      vec_store_le (v10, (64 * 2 + 16 * 2), dst);
+      vec_store_le (v11, (64 * 3 + 16 * 2), dst);
+
+      vec_store_le (v12, (64 * 0 + 16 * 3), dst);
+      vec_store_le (v13, (64 * 1 + 16 * 3), dst);
+      vec_store_le (v14, (64 * 2 + 16 * 3), dst);
+      vec_store_le (v15, (64 * 3 + 16 * 3), dst);
+
+      src += 4*64;
+      dst += 4*64;
+
+      nblks -= 4;
+    }
+  while (nblks);
+
+  vec_vsx_st (state3, 3 * 16, state);
+
+  return 0;
+}
diff --git a/sysdeps/powerpc/powerpc64/power8/chacha20_arch.h b/sysdeps/powerpc/powerpc64/power8/chacha20_arch.h
new file mode 100644
index 0000000000..8aa0bb026c
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power8/chacha20_arch.h
@@ -0,0 +1,36 @@
+/* PowerPC optimization for ChaCha20.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <stdbool.h>
+#include <ldsodefs.h>
+
+unsigned int __chacha20_power8_blocks4 (uint32_t *state, uint8_t *dst,
+					const uint8_t *src, size_t nblks)
+     attribute_hidden;
+
+static void
+chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
+{
+  _Static_assert (CHACHA20_BUFSIZE % 4 == 0,
+		  "CHACHA20_BUFSIZE not multiple of 4");
+  _Static_assert (CHACHA20_BUFSIZE >= CHACHA20_BLOCK_SIZE * 4,
+		  "CHACHA20_BUFSIZE < CHACHA20_BLOCK_SIZE * 4");
+
+  __chacha20_power8_blocks4 (state, dst, src,
+			     CHACHA20_BUFSIZE / CHACHA20_BLOCK_SIZE);
+}
-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH v12 8/9] s390x: Add optimized chacha20
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
                   ` (6 preceding siblings ...)
  2022-07-22 12:21 ` [PATCH v12 7/9] powerpc64: Add " Adhemerval Zanella
@ 2022-07-22 12:21 ` Adhemerval Zanella
  2022-07-22 12:21 ` [PATCH v12 9/9] manual: Add documentation for arc4random functions Adhemerval Zanella
  2022-07-22 19:12 ` [PATCH v12 0/9] Add arc4random support Cristian Rodríguez
  9 siblings, 0 replies; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

It adds vectorized ChaCha20 implementation based on libgcrypt
cipher/chacha20-s390x.S.  The final state register clearing is
omitted.

On a z15 it shows the following improvements (using formatted
bench-arc4random data):

GENERIC                                    MB/s
-----------------------------------------------
arc4random [single-thread]               198.92
arc4random_buf(16) [single-thread]       244.49
arc4random_buf(32) [single-thread]       282.73
arc4random_buf(48) [single-thread]       286.64
arc4random_buf(64) [single-thread]       320.06
arc4random_buf(80) [single-thread]       297.43
arc4random_buf(96) [single-thread]       310.96
arc4random_buf(112) [single-thread]      308.10
arc4random_buf(128) [single-thread]      309.90
-----------------------------------------------

VX.                                        MB/s
-----------------------------------------------
arc4random [single-thread]               430.26
arc4random_buf(16) [single-thread]       735.14
arc4random_buf(32) [single-thread]      1029.99
arc4random_buf(48) [single-thread]      1206.76
arc4random_buf(64) [single-thread]      1311.92
arc4random_buf(80) [single-thread]      1378.74
arc4random_buf(96) [single-thread]      1445.06
arc4random_buf(112) [single-thread]     1484.32
arc4random_buf(128) [single-thread]     1517.30
-----------------------------------------------

Checked on s390x-linux-gnu.
---
 LICENSES                              |   3 +-
 sysdeps/s390/s390-64/Makefile         |   6 +
 sysdeps/s390/s390-64/chacha20-s390x.S | 573 ++++++++++++++++++++++++++
 sysdeps/s390/s390-64/chacha20_arch.h  |  44 ++
 4 files changed, 625 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/s390/s390-64/chacha20-s390x.S
 create mode 100644 sysdeps/s390/s390-64/chacha20_arch.h

diff --git a/LICENSES b/LICENSES
index e177af6035..cd04fb6e84 100644
--- a/LICENSES
+++ b/LICENSES
@@ -392,7 +392,8 @@ Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>
 \f
 sysdeps/aarch64/chacha20-aarch64.S, sysdeps/x86_64/chacha20-amd64-sse2.S,
 sysdeps/x86_64/chacha20-amd64-avx2.S, and
-sysdeps/powerpc/powerpc64/power8/chacha20-ppc.c imports code from libgcrypt,
+sysdeps/powerpc/powerpc64/power8/chacha20-ppc.c, and
+sysdeps/s390/s390-64/chacha20-s390x.S imports code from libgcrypt,
 with the following notices:
 
 Copyright (C) 2017-2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
diff --git a/sysdeps/s390/s390-64/Makefile b/sysdeps/s390/s390-64/Makefile
index 66ed844e68..96c110f490 100644
--- a/sysdeps/s390/s390-64/Makefile
+++ b/sysdeps/s390/s390-64/Makefile
@@ -67,3 +67,9 @@ tests-container += tst-glibc-hwcaps-cache
 endif
 
 endif # $(subdir) == elf
+
+ifeq ($(subdir),stdlib)
+sysdep_routines += \
+  chacha20-s390x \
+  # sysdep_routines
+endif
diff --git a/sysdeps/s390/s390-64/chacha20-s390x.S b/sysdeps/s390/s390-64/chacha20-s390x.S
new file mode 100644
index 0000000000..e38504d370
--- /dev/null
+++ b/sysdeps/s390/s390-64/chacha20-s390x.S
@@ -0,0 +1,573 @@
+/* Optimized s390x implementation of ChaCha20 cipher.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* chacha20-s390x.S  -  zSeries implementation of ChaCha20 cipher
+
+   Copyright (C) 2020 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+
+   This file is part of Libgcrypt.
+
+   Libgcrypt is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of
+   the License, or (at your option) any later version.
+
+   Libgcrypt is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <sysdep.h>
+
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+
+/* CFA expressions are used for pointing CFA and registers to
+ * SP relative offsets. */
+# define DW_REGNO_SP 15
+
+/* Fixed length encoding used for integers for now. */
+# define DW_SLEB128_7BIT(value) \
+        0x00|((value) & 0x7f)
+# define DW_SLEB128_28BIT(value) \
+        0x80|((value)&0x7f), \
+        0x80|(((value)>>7)&0x7f), \
+        0x80|(((value)>>14)&0x7f), \
+        0x00|(((value)>>21)&0x7f)
+
+# define cfi_cfa_on_stack(rsp_offs,cfa_depth) \
+        .cfi_escape \
+          0x0f, /* DW_CFA_def_cfa_expression */ \
+            DW_SLEB128_7BIT(11), /* length */ \
+          0x7f, /* DW_OP_breg15, rsp + constant */ \
+            DW_SLEB128_28BIT(rsp_offs), \
+          0x06, /* DW_OP_deref */ \
+          0x23, /* DW_OP_plus_constu */ \
+            DW_SLEB128_28BIT((cfa_depth)+160)
+
+.machine "z13+vx"
+.text
+
+.balign 16
+.Lconsts:
+.Lwordswap:
+	.byte 12, 13, 14, 15, 8, 9, 10, 11, 4, 5, 6, 7, 0, 1, 2, 3
+.Lbswap128:
+	.byte 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
+.Lbswap32:
+	.byte 3, 2, 1, 0, 7, 6, 5, 4, 11, 10, 9, 8, 15, 14, 13, 12
+.Lone:
+	.long 0, 0, 0, 1
+.Ladd_counter_0123:
+	.long 0, 1, 2, 3
+.Ladd_counter_4567:
+	.long 4, 5, 6, 7
+
+/* register macros */
+#define INPUT %r2
+#define DST   %r3
+#define SRC   %r4
+#define NBLKS %r0
+#define ROUND %r1
+
+/* stack structure */
+
+#define STACK_FRAME_STD    (8 * 16 + 8 * 4)
+#define STACK_FRAME_F8_F15 (8 * 8)
+#define STACK_FRAME_Y0_Y15 (16 * 16)
+#define STACK_FRAME_CTR    (4 * 16)
+#define STACK_FRAME_PARAMS (6 * 8)
+
+#define STACK_MAX   (STACK_FRAME_STD + STACK_FRAME_F8_F15 + \
+		     STACK_FRAME_Y0_Y15 + STACK_FRAME_CTR + \
+		     STACK_FRAME_PARAMS)
+
+#define STACK_F8     (STACK_MAX - STACK_FRAME_F8_F15)
+#define STACK_F9     (STACK_F8 + 8)
+#define STACK_F10    (STACK_F9 + 8)
+#define STACK_F11    (STACK_F10 + 8)
+#define STACK_F12    (STACK_F11 + 8)
+#define STACK_F13    (STACK_F12 + 8)
+#define STACK_F14    (STACK_F13 + 8)
+#define STACK_F15    (STACK_F14 + 8)
+#define STACK_Y0_Y15 (STACK_F8 - STACK_FRAME_Y0_Y15)
+#define STACK_CTR    (STACK_Y0_Y15 - STACK_FRAME_CTR)
+#define STACK_INPUT  (STACK_CTR - STACK_FRAME_PARAMS)
+#define STACK_DST    (STACK_INPUT + 8)
+#define STACK_SRC    (STACK_DST + 8)
+#define STACK_NBLKS  (STACK_SRC + 8)
+#define STACK_POCTX  (STACK_NBLKS + 8)
+#define STACK_POSRC  (STACK_POCTX + 8)
+
+#define STACK_G0_H3  STACK_Y0_Y15
+
+/* vector registers */
+#define A0 %v0
+#define A1 %v1
+#define A2 %v2
+#define A3 %v3
+
+#define B0 %v4
+#define B1 %v5
+#define B2 %v6
+#define B3 %v7
+
+#define C0 %v8
+#define C1 %v9
+#define C2 %v10
+#define C3 %v11
+
+#define D0 %v12
+#define D1 %v13
+#define D2 %v14
+#define D3 %v15
+
+#define E0 %v16
+#define E1 %v17
+#define E2 %v18
+#define E3 %v19
+
+#define F0 %v20
+#define F1 %v21
+#define F2 %v22
+#define F3 %v23
+
+#define G0 %v24
+#define G1 %v25
+#define G2 %v26
+#define G3 %v27
+
+#define H0 %v28
+#define H1 %v29
+#define H2 %v30
+#define H3 %v31
+
+#define IO0 E0
+#define IO1 E1
+#define IO2 E2
+#define IO3 E3
+#define IO4 F0
+#define IO5 F1
+#define IO6 F2
+#define IO7 F3
+
+#define S0 G0
+#define S1 G1
+#define S2 G2
+#define S3 G3
+
+#define TMP0 H0
+#define TMP1 H1
+#define TMP2 H2
+#define TMP3 H3
+
+#define X0 A0
+#define X1 A1
+#define X2 A2
+#define X3 A3
+#define X4 B0
+#define X5 B1
+#define X6 B2
+#define X7 B3
+#define X8 C0
+#define X9 C1
+#define X10 C2
+#define X11 C3
+#define X12 D0
+#define X13 D1
+#define X14 D2
+#define X15 D3
+
+#define Y0 E0
+#define Y1 E1
+#define Y2 E2
+#define Y3 E3
+#define Y4 F0
+#define Y5 F1
+#define Y6 F2
+#define Y7 F3
+#define Y8 G0
+#define Y9 G1
+#define Y10 G2
+#define Y11 G3
+#define Y12 H0
+#define Y13 H1
+#define Y14 H2
+#define Y15 H3
+
+/**********************************************************************
+  helper macros
+ **********************************************************************/
+
+#define _ /*_*/
+
+#define START_STACK(last_r) \
+	lgr %r0, %r15; \
+	lghi %r1, ~15; \
+	stmg %r6, last_r, 6 * 8(%r15); \
+	aghi %r0, -STACK_MAX; \
+	ngr %r0, %r1; \
+	lgr %r1, %r15; \
+	cfi_def_cfa_register(1); \
+	lgr %r15, %r0; \
+	stg %r1, 0(%r15); \
+	cfi_cfa_on_stack(0, 0); \
+	std %f8, STACK_F8(%r15); \
+	std %f9, STACK_F9(%r15); \
+	std %f10, STACK_F10(%r15); \
+	std %f11, STACK_F11(%r15); \
+	std %f12, STACK_F12(%r15); \
+	std %f13, STACK_F13(%r15); \
+	std %f14, STACK_F14(%r15); \
+	std %f15, STACK_F15(%r15);
+
+#define END_STACK(last_r) \
+	lg %r1, 0(%r15); \
+	ld %f8, STACK_F8(%r15); \
+	ld %f9, STACK_F9(%r15); \
+	ld %f10, STACK_F10(%r15); \
+	ld %f11, STACK_F11(%r15); \
+	ld %f12, STACK_F12(%r15); \
+	ld %f13, STACK_F13(%r15); \
+	ld %f14, STACK_F14(%r15); \
+	ld %f15, STACK_F15(%r15); \
+	lmg %r6, last_r, 6 * 8(%r1); \
+	lgr %r15, %r1; \
+	cfi_def_cfa_register(DW_REGNO_SP);
+
+#define PLUS(dst,src) \
+	vaf dst, dst, src;
+
+#define XOR(dst,src) \
+	vx dst, dst, src;
+
+#define ROTATE(v1,c) \
+	verllf v1, v1, (c)(0);
+
+#define WORD_ROTATE(v1,s) \
+	vsldb v1, v1, v1, ((s) * 4);
+
+#define DST_8(OPER, I, J) \
+	OPER(A##I, J); OPER(B##I, J); OPER(C##I, J); OPER(D##I, J); \
+	OPER(E##I, J); OPER(F##I, J); OPER(G##I, J); OPER(H##I, J);
+
+/**********************************************************************
+  round macros
+ **********************************************************************/
+
+/**********************************************************************
+  8-way chacha20 ("vertical")
+ **********************************************************************/
+
+#define QUARTERROUND4_V8_POLY(x0,x1,x2,x3,x4,x5,x6,x7,\
+			      x8,x9,x10,x11,x12,x13,x14,x15,\
+			      y0,y1,y2,y3,y4,y5,y6,y7,\
+			      y8,y9,y10,y11,y12,y13,y14,y15,\
+			      op1,op2,op3,op4,op5,op6,op7,op8,\
+			      op9,op10,op11,op12) \
+	op1;							\
+	PLUS(x0, x1); PLUS(x4, x5);				\
+	PLUS(x8, x9); PLUS(x12, x13);				\
+	PLUS(y0, y1); PLUS(y4, y5);				\
+	PLUS(y8, y9); PLUS(y12, y13);				\
+	    op2;						\
+	    XOR(x3, x0);  XOR(x7, x4);				\
+	    XOR(x11, x8); XOR(x15, x12);			\
+	    XOR(y3, y0);  XOR(y7, y4);				\
+	    XOR(y11, y8); XOR(y15, y12);			\
+		op3;						\
+		ROTATE(x3, 16); ROTATE(x7, 16);			\
+		ROTATE(x11, 16); ROTATE(x15, 16);		\
+		ROTATE(y3, 16); ROTATE(y7, 16);			\
+		ROTATE(y11, 16); ROTATE(y15, 16);		\
+	op4;							\
+	PLUS(x2, x3); PLUS(x6, x7);				\
+	PLUS(x10, x11); PLUS(x14, x15);				\
+	PLUS(y2, y3); PLUS(y6, y7);				\
+	PLUS(y10, y11); PLUS(y14, y15);				\
+	    op5;						\
+	    XOR(x1, x2); XOR(x5, x6);				\
+	    XOR(x9, x10); XOR(x13, x14);			\
+	    XOR(y1, y2); XOR(y5, y6);				\
+	    XOR(y9, y10); XOR(y13, y14);			\
+		op6;						\
+		ROTATE(x1,12); ROTATE(x5,12);			\
+		ROTATE(x9,12); ROTATE(x13,12);			\
+		ROTATE(y1,12); ROTATE(y5,12);			\
+		ROTATE(y9,12); ROTATE(y13,12);			\
+	op7;							\
+	PLUS(x0, x1); PLUS(x4, x5);				\
+	PLUS(x8, x9); PLUS(x12, x13);				\
+	PLUS(y0, y1); PLUS(y4, y5);				\
+	PLUS(y8, y9); PLUS(y12, y13);				\
+	    op8;						\
+	    XOR(x3, x0); XOR(x7, x4);				\
+	    XOR(x11, x8); XOR(x15, x12);			\
+	    XOR(y3, y0); XOR(y7, y4);				\
+	    XOR(y11, y8); XOR(y15, y12);			\
+		op9;						\
+		ROTATE(x3,8); ROTATE(x7,8);			\
+		ROTATE(x11,8); ROTATE(x15,8);			\
+		ROTATE(y3,8); ROTATE(y7,8);			\
+		ROTATE(y11,8); ROTATE(y15,8);			\
+	op10;							\
+	PLUS(x2, x3); PLUS(x6, x7);				\
+	PLUS(x10, x11); PLUS(x14, x15);				\
+	PLUS(y2, y3); PLUS(y6, y7);				\
+	PLUS(y10, y11); PLUS(y14, y15);				\
+	    op11;						\
+	    XOR(x1, x2); XOR(x5, x6);				\
+	    XOR(x9, x10); XOR(x13, x14);			\
+	    XOR(y1, y2); XOR(y5, y6);				\
+	    XOR(y9, y10); XOR(y13, y14);			\
+		op12;						\
+		ROTATE(x1,7); ROTATE(x5,7);			\
+		ROTATE(x9,7); ROTATE(x13,7);			\
+		ROTATE(y1,7); ROTATE(y5,7);			\
+		ROTATE(y9,7); ROTATE(y13,7);
+
+#define QUARTERROUND4_V8(x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15,\
+			 y0,y1,y2,y3,y4,y5,y6,y7,y8,y9,y10,y11,y12,y13,y14,y15) \
+	QUARTERROUND4_V8_POLY(x0,x1,x2,x3,x4,x5,x6,x7,\
+			      x8,x9,x10,x11,x12,x13,x14,x15,\
+			      y0,y1,y2,y3,y4,y5,y6,y7,\
+			      y8,y9,y10,y11,y12,y13,y14,y15,\
+			      ,,,,,,,,,,,)
+
+#define TRANSPOSE_4X4_2(v0,v1,v2,v3,va,vb,vc,vd,tmp0,tmp1,tmp2,tmpa,tmpb,tmpc) \
+	  vmrhf tmp0, v0, v1;					\
+	  vmrhf tmp1, v2, v3;					\
+	  vmrlf tmp2, v0, v1;					\
+	  vmrlf   v3, v2, v3;					\
+	  vmrhf tmpa, va, vb;					\
+	  vmrhf tmpb, vc, vd;					\
+	  vmrlf tmpc, va, vb;					\
+	  vmrlf   vd, vc, vd;					\
+	  vpdi v0, tmp0, tmp1, 0;				\
+	  vpdi v1, tmp0, tmp1, 5;				\
+	  vpdi v2, tmp2,   v3, 0;				\
+	  vpdi v3, tmp2,   v3, 5;				\
+	  vpdi va, tmpa, tmpb, 0;				\
+	  vpdi vb, tmpa, tmpb, 5;				\
+	  vpdi vc, tmpc,   vd, 0;				\
+	  vpdi vd, tmpc,   vd, 5;
+
+.balign 8
+.globl __chacha20_s390x_vx_blocks8
+ENTRY (__chacha20_s390x_vx_blocks8)
+	/* input:
+	 *	%r2: input
+	 *	%r3: dst
+	 *	%r4: src
+	 *	%r5: nblks (multiple of 8)
+	 */
+
+	START_STACK(%r8);
+	lgr NBLKS, %r5;
+
+	larl %r7, .Lconsts;
+
+	/* Load counter. */
+	lg %r8, (12 * 4)(INPUT);
+	rllg %r8, %r8, 32;
+
+.balign 4
+	/* Process eight chacha20 blocks per loop. */
+.Lloop8:
+	vlm Y0, Y3, 0(INPUT);
+
+	slgfi NBLKS, 8;
+	lghi ROUND, (20 / 2);
+
+	/* Construct counter vectors X12/X13 & Y12/Y13. */
+	vl X4, (.Ladd_counter_0123 - .Lconsts)(%r7);
+	vl Y4, (.Ladd_counter_4567 - .Lconsts)(%r7);
+	vrepf Y12, Y3, 0;
+	vrepf Y13, Y3, 1;
+	vaccf X5, Y12, X4;
+	vaccf Y5, Y12, Y4;
+	vaf X12, Y12, X4;
+	vaf Y12, Y12, Y4;
+	vaf X13, Y13, X5;
+	vaf Y13, Y13, Y5;
+
+	vrepf X0, Y0, 0;
+	vrepf X1, Y0, 1;
+	vrepf X2, Y0, 2;
+	vrepf X3, Y0, 3;
+	vrepf X4, Y1, 0;
+	vrepf X5, Y1, 1;
+	vrepf X6, Y1, 2;
+	vrepf X7, Y1, 3;
+	vrepf X8, Y2, 0;
+	vrepf X9, Y2, 1;
+	vrepf X10, Y2, 2;
+	vrepf X11, Y2, 3;
+	vrepf X14, Y3, 2;
+	vrepf X15, Y3, 3;
+
+	/* Store counters for blocks 0-7. */
+	vstm X12, X13, (STACK_CTR + 0 * 16)(%r15);
+	vstm Y12, Y13, (STACK_CTR + 2 * 16)(%r15);
+
+	vlr Y0, X0;
+	vlr Y1, X1;
+	vlr Y2, X2;
+	vlr Y3, X3;
+	vlr Y4, X4;
+	vlr Y5, X5;
+	vlr Y6, X6;
+	vlr Y7, X7;
+	vlr Y8, X8;
+	vlr Y9, X9;
+	vlr Y10, X10;
+	vlr Y11, X11;
+	vlr Y14, X14;
+	vlr Y15, X15;
+
+	/* Update and store counter. */
+	agfi %r8, 8;
+	rllg %r5, %r8, 32;
+	stg %r5, (12 * 4)(INPUT);
+
+.balign 4
+.Lround2_8:
+	QUARTERROUND4_V8(X0, X4,  X8, X12,   X1, X5,  X9, X13,
+			 X2, X6, X10, X14,   X3, X7, X11, X15,
+			 Y0, Y4,  Y8, Y12,   Y1, Y5,  Y9, Y13,
+			 Y2, Y6, Y10, Y14,   Y3, Y7, Y11, Y15);
+	QUARTERROUND4_V8(X0, X5, X10, X15,   X1, X6, X11, X12,
+			 X2, X7,  X8, X13,   X3, X4,  X9, X14,
+			 Y0, Y5, Y10, Y15,   Y1, Y6, Y11, Y12,
+			 Y2, Y7,  Y8, Y13,   Y3, Y4,  Y9, Y14);
+	brctg ROUND, .Lround2_8;
+
+	/* Store blocks 4-7. */
+	vstm Y0, Y15, STACK_Y0_Y15(%r15);
+
+	/* Load counters for blocks 0-3. */
+	vlm Y0, Y1, (STACK_CTR + 0 * 16)(%r15);
+
+	lghi ROUND, 1;
+	j .Lfirst_output_4blks_8;
+
+.balign 4
+.Lsecond_output_4blks_8:
+	/* Load blocks 4-7. */
+	vlm X0, X15, STACK_Y0_Y15(%r15);
+
+	/* Load counters for blocks 4-7. */
+	vlm Y0, Y1, (STACK_CTR + 2 * 16)(%r15);
+
+	lghi ROUND, 0;
+
+.balign 4
+	/* Output four chacha20 blocks per loop. */
+.Lfirst_output_4blks_8:
+	vlm Y12, Y15, 0(INPUT);
+	PLUS(X12, Y0);
+	PLUS(X13, Y1);
+	vrepf Y0, Y12, 0;
+	vrepf Y1, Y12, 1;
+	vrepf Y2, Y12, 2;
+	vrepf Y3, Y12, 3;
+	vrepf Y4, Y13, 0;
+	vrepf Y5, Y13, 1;
+	vrepf Y6, Y13, 2;
+	vrepf Y7, Y13, 3;
+	vrepf Y8, Y14, 0;
+	vrepf Y9, Y14, 1;
+	vrepf Y10, Y14, 2;
+	vrepf Y11, Y14, 3;
+	vrepf Y14, Y15, 2;
+	vrepf Y15, Y15, 3;
+	PLUS(X0, Y0);
+	PLUS(X1, Y1);
+	PLUS(X2, Y2);
+	PLUS(X3, Y3);
+	PLUS(X4, Y4);
+	PLUS(X5, Y5);
+	PLUS(X6, Y6);
+	PLUS(X7, Y7);
+	PLUS(X8, Y8);
+	PLUS(X9, Y9);
+	PLUS(X10, Y10);
+	PLUS(X11, Y11);
+	PLUS(X14, Y14);
+	PLUS(X15, Y15);
+
+	vl Y15, (.Lbswap32 - .Lconsts)(%r7);
+	TRANSPOSE_4X4_2(X0, X1, X2, X3, X4, X5, X6, X7,
+			Y9, Y10, Y11, Y12, Y13, Y14);
+	TRANSPOSE_4X4_2(X8, X9, X10, X11, X12, X13, X14, X15,
+			Y9, Y10, Y11, Y12, Y13, Y14);
+
+	vlm Y0, Y14, 0(SRC);
+	vperm X0, X0, X0, Y15;
+	vperm X1, X1, X1, Y15;
+	vperm X2, X2, X2, Y15;
+	vperm X3, X3, X3, Y15;
+	vperm X4, X4, X4, Y15;
+	vperm X5, X5, X5, Y15;
+	vperm X6, X6, X6, Y15;
+	vperm X7, X7, X7, Y15;
+	vperm X8, X8, X8, Y15;
+	vperm X9, X9, X9, Y15;
+	vperm X10, X10, X10, Y15;
+	vperm X11, X11, X11, Y15;
+	vperm X12, X12, X12, Y15;
+	vperm X13, X13, X13, Y15;
+	vperm X14, X14, X14, Y15;
+	vperm X15, X15, X15, Y15;
+	vl Y15, (15 * 16)(SRC);
+
+	XOR(Y0, X0);
+	XOR(Y1, X4);
+	XOR(Y2, X8);
+	XOR(Y3, X12);
+	XOR(Y4, X1);
+	XOR(Y5, X5);
+	XOR(Y6, X9);
+	XOR(Y7, X13);
+	XOR(Y8, X2);
+	XOR(Y9, X6);
+	XOR(Y10, X10);
+	XOR(Y11, X14);
+	XOR(Y12, X3);
+	XOR(Y13, X7);
+	XOR(Y14, X11);
+	XOR(Y15, X15);
+	vstm Y0, Y15, 0(DST);
+
+	aghi SRC, 256;
+	aghi DST, 256;
+
+	clgije ROUND, 1, .Lsecond_output_4blks_8;
+
+	clgijhe NBLKS, 8, .Lloop8;
+
+
+	END_STACK(%r8);
+	xgr %r2, %r2;
+	br %r14;
+END (__chacha20_s390x_vx_blocks8)
+
+#endif /* HAVE_S390_VX_ASM_SUPPORT */
diff --git a/sysdeps/s390/s390-64/chacha20_arch.h b/sysdeps/s390/s390-64/chacha20_arch.h
new file mode 100644
index 0000000000..fdd197cb37
--- /dev/null
+++ b/sysdeps/s390/s390-64/chacha20_arch.h
@@ -0,0 +1,44 @@
+/* s390x optimization for ChaCha20.VE_S390_VX_ASM_SUPPORT
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <stdbool.h>
+#include <ldsodefs.h>
+#include <sys/auxv.h>
+
+unsigned int __chacha20_s390x_vx_blocks8 (uint32_t *state, uint8_t *dst,
+					  const uint8_t *src, size_t nblks)
+     attribute_hidden;
+
+static inline void
+chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
+{
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+  _Static_assert (CHACHA20_BUFSIZE % 8 == 0,
+		  "CHACHA20_BUFSIZE not multiple of 8");
+  _Static_assert (CHACHA20_BUFSIZE >= CHACHA20_BLOCK_SIZE * 8,
+		  "CHACHA20_BUFSIZE < CHACHA20_BLOCK_SIZE * 8");
+
+  if (GLRO(dl_hwcap) & HWCAP_S390_VX)
+    {
+      __chacha20_s390x_vx_blocks8 (state, dst, src,
+				   CHACHA20_BUFSIZE / CHACHA20_BLOCK_SIZE);
+      return;
+    }
+#endif
+  chacha20_crypt_generic (state, dst, src);
+}
-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH v12 9/9] manual: Add documentation for arc4random functions
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
                   ` (7 preceding siblings ...)
  2022-07-22 12:21 ` [PATCH v12 8/9] s390x: " Adhemerval Zanella
@ 2022-07-22 12:21 ` Adhemerval Zanella
  2022-07-22 15:33   ` Zack Weinberg
  2022-07-22 19:12 ` [PATCH v12 0/9] Add arc4random support Cristian Rodríguez
  9 siblings, 1 reply; 20+ messages in thread
From: Adhemerval Zanella @ 2022-07-22 12:21 UTC (permalink / raw)
  To: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

---
 manual/math.texi | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/manual/math.texi b/manual/math.texi
index 477a18b6d1..141695cc30 100644
--- a/manual/math.texi
+++ b/manual/math.texi
@@ -1447,6 +1447,7 @@ systems.
 * ISO Random::                  @code{rand} and friends.
 * BSD Random::                  @code{random} and friends.
 * SVID Random::                 @code{drand48} and friends.
+* High Quality Random::         @code{arc4random} and friends.
 @end menu
 
 @node ISO Random
@@ -1985,6 +1986,51 @@ This function is a GNU extension and should not be used in portable
 programs.
 @end deftypefun
 
+@node High Quality Random
+@subsection High Quality Random Number Functions
+
+This section describes the random number functions provided as a GNU
+extension, based on OpenBSD interfaces.
+
+@Theglibc{} uses kernel entropy obtained either through @code{getrandom}
+or by reading @file{/dev/urandom} to seed and periodically re-seed the
+internal state.  A per-thread data pool is used, which allows fast output
+generation.
+
+Although these functions provide higher random quality than ISO, BSD, and
+SVID functions, these still use a Pseudo-Random generator and should not
+be used in cryptographic contexts.
+
+The internal state is cleared and reseeded with kernel entropy on @code{fork}
+and @code{_Fork}.  It is not cleared on either a direct @code{clone} syscall
+or when using @theglibc{} @code{syscall} function.
+
+The prototypes for these functions are in @file{stdlib.h}.
+@pindex stdlib.h
+
+@deftypefun uint32_t arc4random (void)
+@standards{BSD, stdlib.h}
+@safety{@mtsafe{}@asunsafe{@asucorrupt{}}@acsafe{}}
+This function returns a single 32-bit value in the range of @code{0} to
+@code{2^32−1} (inclusive), which is twice the range of @code{rand} and
+@code{random}.
+@end deftypefun
+
+@deftypefun void arc4random_buf (void *@var{buffer}, size_t @var{length})
+@standards{BSD, stdlib.h}
+@safety{@mtsafe{}@asunsafe{@asucorrupt{}}@acsafe{}}
+This function fills the region @var{buffer} of length @var{length} bytes
+with random data.
+@end deftypefun
+
+@deftypefun uint32_t arc4random_uniform (uint32_t @var{upper_bound})
+@standards{BSD, stdlib.h}
+@safety{@mtsafe{}@asunsafe{@asucorrupt{}}@acsafe{}}
+This function returns a single 32-bit value, uniformly distributed but
+less than the @var{upper_bound}.  It avoids the @w{modulo bias} when the
+upper bound is not a power of two.
+@end deftypefun
+
 @node FP Function Optimizations
 @section Is Fast Code or Small Code preferred?
 @cindex Optimization
-- 
2.34.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417)
  2022-07-22 12:21 ` [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417) Adhemerval Zanella
@ 2022-07-22 12:35   ` Florian Weimer
  2022-07-22 13:00     ` Adhemerval Zanella Netto
  2022-07-22 15:31   ` Zack Weinberg
  1 sibling, 1 reply; 20+ messages in thread
From: Florian Weimer @ 2022-07-22 12:35 UTC (permalink / raw)
  To: Adhemerval Zanella
  Cc: libc-alpha, Carlos O'Donell, Szabolcs Nagy, Yann Droneaud

* Adhemerval Zanella:

> diff --git a/stdlib/chacha20.c b/stdlib/chacha20.c
> new file mode 100644
> index 0000000000..77e37655cd
> --- /dev/null
> +++ b/stdlib/chacha20.c
> @@ -0,0 +1,179 @@

> +static void
> +chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
> +{
> +  size_t bytes = CHACHA20_BUFSIZE;
> +  while (bytes >= CHACHA20_BLOCK_SIZE)

That doesn't look right.  No bytes variable.

The chacha20_crypt functions should probably use arguments in the style
of

  uint8_t dst[static CHACHA20_BUFSIZE]

for compiler size checking.

Thanks,
Florian


^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417)
  2022-07-22 12:35   ` Florian Weimer
@ 2022-07-22 13:00     ` Adhemerval Zanella Netto
  0 siblings, 0 replies; 20+ messages in thread
From: Adhemerval Zanella Netto @ 2022-07-22 13:00 UTC (permalink / raw)
  To: Florian Weimer
  Cc: libc-alpha, Carlos O'Donell, Szabolcs Nagy, Yann Droneaud



On 22/07/22 09:35, Florian Weimer wrote:
> * Adhemerval Zanella:
> 
>> diff --git a/stdlib/chacha20.c b/stdlib/chacha20.c
>> new file mode 100644
>> index 0000000000..77e37655cd
>> --- /dev/null
>> +++ b/stdlib/chacha20.c
>> @@ -0,0 +1,179 @@
> 
>> +static void
>> +chacha20_crypt (uint32_t *state, uint8_t *dst, const uint8_t *src)
>> +{
>> +  size_t bytes = CHACHA20_BUFSIZE;
>> +  while (bytes >= CHACHA20_BLOCK_SIZE)
> 
> That doesn't look right.  No bytes variable.
> 
> The chacha20_crypt functions should probably use arguments in the style
> of
> 
>   uint8_t dst[static CHACHA20_BUFSIZE]
> 
> for compiler size checking.

Would it be acceptable?

diff --git a/stdlib/chacha20.c b/stdlib/chacha20.c
index 07b7b203f2..4217ecb06f 100644
--- a/stdlib/chacha20.c
+++ b/stdlib/chacha20.c
@@ -166,14 +166,15 @@ chacha20_block (uint32_t *state, uint8_t *dst, const uint8_t *src)

 static void
 __attribute_maybe_unused__
-chacha20_crypt_generic (uint32_t *state, uint8_t *dst, const uint8_t *src)
+chacha20_crypt_generic (uint32_t *state, uint8_t dst[static CHACHA20_BUFSIZE],
+                       const uint8_t *src)
 {
-  size_t bytes = CHACHA20_BUFSIZE;
-  while (bytes >= CHACHA20_BLOCK_SIZE)
+  size_t dstlen = CHACHA20_BUFSIZE;
+  while (dstlen >= CHACHA20_BLOCK_SIZE)
     {
       chacha20_block (state, dst, src);

-      bytes -= CHACHA20_BLOCK_SIZE;
+      dstlen -= CHACHA20_BLOCK_SIZE;
       dst += CHACHA20_BLOCK_SIZE;
       src += CHACHA20_BLOCK_SIZE;
     }

^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417)
  2022-07-22 12:21 ` [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417) Adhemerval Zanella
  2022-07-22 12:35   ` Florian Weimer
@ 2022-07-22 15:31   ` Zack Weinberg
  2022-07-22 17:00     ` Adhemerval Zanella Netto
  1 sibling, 1 reply; 20+ messages in thread
From: Zack Weinberg @ 2022-07-22 15:31 UTC (permalink / raw)
  To: libc-alpha

On 2022-07-22 8:21 AM, Adhemerval Zanella via Libc-alpha wrote:
> diff --git a/NEWS b/NEWS
> index df882ec243..8420a65cd0 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -60,6 +60,10 @@ Major new features:
>     _GNU_SOURCE macro is defined and the C++20 __cpp_char8_t feature test macro
>     is not defined (if __cpp_char8_t is defined, then char8_t is a builtin type).
>   
> +* The functions arc4random, arc4random_buf, and arc4random_uniform have been
> +  added.  The functions use a pseudo-random number generator along with
> +  entropy from the kernel.
> +

I think the second sentence ought to be a little more specific than "a 
pseudo-random number generator", since the whole point of the 
arc4random* API is that it's supposed to be cryptographically strong, 
and since the name (incorrectly) suggests that a *known-broken* CSPRNG 
is in use.  Maybe something like

"These functions implement a cryptographically strong pseudo-random 
number generator, based on ChaCha20 and automatically seeded from 
kernel-provided entropy."

 > reseeds the internal state on every 16MB of consumed buffer

Is this sufficient to provide forward security (i.e. a state leak does 
not permit the attacker to reconstruct past outputs of the RNG)?

zw

^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 9/9] manual: Add documentation for arc4random functions
  2022-07-22 12:21 ` [PATCH v12 9/9] manual: Add documentation for arc4random functions Adhemerval Zanella
@ 2022-07-22 15:33   ` Zack Weinberg
  2022-07-22 17:15     ` Adhemerval Zanella Netto
  0 siblings, 1 reply; 20+ messages in thread
From: Zack Weinberg @ 2022-07-22 15:33 UTC (permalink / raw)
  To: libc-alpha

On 2022-07-22 8:21 AM, Adhemerval Zanella via Libc-alpha wrote:
> +Although these functions provide higher random quality than ISO, BSD, and
> +SVID functions, these still use a Pseudo-Random generator and should not
> +be used in cryptographic contexts.

Huh? Isn't the whole point of arc4random that it _is_ cryptographically 
strong?

zw

^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417)
  2022-07-22 15:31   ` Zack Weinberg
@ 2022-07-22 17:00     ` Adhemerval Zanella Netto
  0 siblings, 0 replies; 20+ messages in thread
From: Adhemerval Zanella Netto @ 2022-07-22 17:00 UTC (permalink / raw)
  To: libc-alpha



On 22/07/22 12:31, Zack Weinberg via Libc-alpha wrote:
> On 2022-07-22 8:21 AM, Adhemerval Zanella via Libc-alpha wrote:
>> diff --git a/NEWS b/NEWS
>> index df882ec243..8420a65cd0 100644
>> --- a/NEWS
>> +++ b/NEWS
>> @@ -60,6 +60,10 @@ Major new features:
>>     _GNU_SOURCE macro is defined and the C++20 __cpp_char8_t feature test macro
>>     is not defined (if __cpp_char8_t is defined, then char8_t is a builtin type).
>>   +* The functions arc4random, arc4random_buf, and arc4random_uniform have been
>> +  added.  The functions use a pseudo-random number generator along with
>> +  entropy from the kernel.
>> +
> 
> I think the second sentence ought to be a little more specific than "a pseudo-random number generator", since the whole point of the arc4random* API is that it's supposed to be cryptographically strong, and since the name (incorrectly) suggests that a *known-broken* CSPRNG is in use.  Maybe something like
> 
> "These functions implement a cryptographically strong pseudo-random number generator, based on ChaCha20 and automatically seeded from kernel-provided entropy."

My understanding is we do not really want to state this scheme used is a CRNG,
since it might create an additional certification requirement (such as FIPS)
nor I have the cryptographic background to certify it follows the requirements
(although reading http://blog.cr.yp.to/20170723-random.html it does follow the
idea and it also based on already deployed implementations like openbsd).

> 
>> reseeds the internal state on every 16MB of consumed buffer
> 
> Is this sufficient to provide forward security (i.e. a state leak does not permit the attacker to reconstruct past outputs of the RNG)?
> 
> zw

I am not sure, openbsd implementation stir value was added without much comment
why the value was chosen.  Should we tune a lower bound? 


^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 9/9] manual: Add documentation for arc4random functions
  2022-07-22 15:33   ` Zack Weinberg
@ 2022-07-22 17:15     ` Adhemerval Zanella Netto
  2022-07-24 15:20       ` Zack Weinberg
  0 siblings, 1 reply; 20+ messages in thread
From: Adhemerval Zanella Netto @ 2022-07-22 17:15 UTC (permalink / raw)
  To: Zack Weinberg, libc-alpha



On 22/07/22 12:33, Zack Weinberg via Libc-alpha wrote:
> On 2022-07-22 8:21 AM, Adhemerval Zanella via Libc-alpha wrote:
>> +Although these functions provide higher random quality than ISO, BSD, and
>> +SVID functions, these still use a Pseudo-Random generator and should not
>> +be used in cryptographic contexts.
> 
> Huh? Isn't the whole point of arc4random that it _is_ cryptographically strong?
> 
> zw

Even OpenBSD manual is not clear about it [1].  This implementation is similar
to OpenBSD, the main differences is that glibc implements a per-thread buffer
instead of a global state (and although OpenBSD does think a global state is 
good qualitiy the are candid say they have no formal proof of these 
qualities [2]); and fork handling is done by glibc instead of relying on 
kernel (I do want to see if we can use a block allocator in this case).

The main problem is if we state this is a CSRNG we need to certify somehow,
which I don't have the background to do; and it might incur in extra 
certification depending of the intended glibc usage [2].

So I think it would be a more conservative approach to state our implementation
is not a CSRNG (although it does follow most of the principles layout as 
fast-key-erasure random-number generators [4]).

[1] https://sourceware.org/pipermail/libc-alpha/2022-July/140728.html
[2] https://www.youtube.com/watch?v=gp_90-3R0pE
[3] https://sourceware.org/pipermail/libc-alpha/2022-July/140782.html
[4] http://blog.cr.yp.to/20170723-random.html

^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 0/9] Add arc4random support
  2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
                   ` (8 preceding siblings ...)
  2022-07-22 12:21 ` [PATCH v12 9/9] manual: Add documentation for arc4random functions Adhemerval Zanella
@ 2022-07-22 19:12 ` Cristian Rodríguez
  2022-07-22 21:35   ` Adhemerval Zanella Netto
  9 siblings, 1 reply; 20+ messages in thread
From: Cristian Rodríguez @ 2022-07-22 19:12 UTC (permalink / raw)
  To: Adhemerval Zanella
  Cc: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy

On the BSDs the state is allocated with mmap...that would allow it to
safely use it within the malloc implementation..(or paths that should
not call malloc for whatever reason)
just wondering why changing was a choice.

^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 0/9] Add arc4random support
  2022-07-22 19:12 ` [PATCH v12 0/9] Add arc4random support Cristian Rodríguez
@ 2022-07-22 21:35   ` Adhemerval Zanella Netto
  0 siblings, 0 replies; 20+ messages in thread
From: Adhemerval Zanella Netto @ 2022-07-22 21:35 UTC (permalink / raw)
  To: Cristian Rodríguez
  Cc: libc-alpha, Florian Weimer, Carlos O'Donell, Szabolcs Nagy



On 22/07/22 16:12, Cristian Rodríguez wrote:
> On the BSDs the state is allocated with mmap...that would allow it to
> safely use it within the malloc implementation..(or paths that should
> not call malloc for whatever reason)
> just wondering why changing was a choice.

Because it was easiest solution to provide lazy allocation for the
internal buffer, on a previous version I added on TCB but Florian asked
to move to a dynamic buffer because it was too large to impose on every
thread (I tend to agree).

I plan to revise and maybe add a custom allocator so we can also use
MADV_DONTFORK.

^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 9/9] manual: Add documentation for arc4random functions
  2022-07-22 17:15     ` Adhemerval Zanella Netto
@ 2022-07-24 15:20       ` Zack Weinberg
  0 siblings, 0 replies; 20+ messages in thread
From: Zack Weinberg @ 2022-07-24 15:20 UTC (permalink / raw)
  To: Adhemerval Zanella, GNU libc development

On Fri, Jul 22, 2022, at 1:15 PM, Adhemerval Zanella Netto wrote:
> On 22/07/22 12:33, Zack Weinberg via Libc-alpha wrote:
>> On 2022-07-22 8:21 AM, Adhemerval Zanella via Libc-alpha wrote:
>>> +Although these functions provide higher random quality than ISO, BSD, and
>>> +SVID functions, these still use a Pseudo-Random generator and should not
>>> +be used in cryptographic contexts.
>>
>> Huh? Isn't the whole point of arc4random that it _is_
>> cryptographically strong?
>
> Even OpenBSD manual is not clear about it [1].
...
> The main problem is if we state this is a CSRNG we need to certify
> somehow, which I don't have the background to do; and it might incur
> in extra certification depending of the intended glibc usage [2].
> So I think it would be a more conservative approach to state our
> implementation is not a CSRNG ...

My main concern with saying "still uses a Pseudo-Random Generator" and
"should not be used in cryptographic contexts" is that, since we
resisted adding this API for so long, people might think we did the
bare minimum and it shouldn't actually be used at all.

How about this?

# These functions use a cryptographic-strength random number
# generation _algorithm_ (currently ChaCha20) but the implementation
# has not been validated for use in security-critical contexts.

zw

^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH v12 7/9] powerpc64: Add optimized chacha20
  2022-07-22 12:21 ` [PATCH v12 7/9] powerpc64: Add " Adhemerval Zanella
@ 2022-07-27 14:09   ` Tulio Magno Quites Machado Filho
  0 siblings, 0 replies; 20+ messages in thread
From: Tulio Magno Quites Machado Filho @ 2022-07-27 14:09 UTC (permalink / raw)
  To: Adhemerval Zanella, libc-alpha, Florian Weimer,
	Carlos O'Donell, Szabolcs Nagy
  Cc: Paul E . Murphy

Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org> writes:

> It adds vectorized ChaCha20 implementation based on libgcrypt
> cipher/chacha20-ppc.c.  It targets POWER8 and it is used on default
> for LE.
>

Last month, libgcrypt merged a Power10 optimization for chacha20.
With that said, I think the new optimization can be merged at a later time.
This patch LGTM as-is.

Thanks!

-- 
Tulio Magno

^ permalink raw reply	[flat|nested] 20+ messages in thread

end of thread, other threads:[~2022-07-27 14:09 UTC | newest]

Thread overview: 20+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-07-22 12:21 [PATCH v12 0/9] Add arc4random support Adhemerval Zanella
2022-07-22 12:21 ` [PATCH v12 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417) Adhemerval Zanella
2022-07-22 12:35   ` Florian Weimer
2022-07-22 13:00     ` Adhemerval Zanella Netto
2022-07-22 15:31   ` Zack Weinberg
2022-07-22 17:00     ` Adhemerval Zanella Netto
2022-07-22 12:21 ` [PATCH v12 2/9] stdlib: Add arc4random tests Adhemerval Zanella
2022-07-22 12:21 ` [PATCH v12 3/9] benchtests: Add arc4random benchtest Adhemerval Zanella
2022-07-22 12:21 ` [PATCH v12 4/9] aarch64: Add optimized chacha20 Adhemerval Zanella
2022-07-22 12:21 ` [PATCH v12 5/9] x86: Add SSE2 " Adhemerval Zanella
2022-07-22 12:21 ` [PATCH v12 6/9] x86: Add AVX2 " Adhemerval Zanella
2022-07-22 12:21 ` [PATCH v12 7/9] powerpc64: Add " Adhemerval Zanella
2022-07-27 14:09   ` Tulio Magno Quites Machado Filho
2022-07-22 12:21 ` [PATCH v12 8/9] s390x: " Adhemerval Zanella
2022-07-22 12:21 ` [PATCH v12 9/9] manual: Add documentation for arc4random functions Adhemerval Zanella
2022-07-22 15:33   ` Zack Weinberg
2022-07-22 17:15     ` Adhemerval Zanella Netto
2022-07-24 15:20       ` Zack Weinberg
2022-07-22 19:12 ` [PATCH v12 0/9] Add arc4random support Cristian Rodríguez
2022-07-22 21:35   ` Adhemerval Zanella Netto

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