* Re: [PATCH v10 1/1] x86: Update _dl_tlsdesc_dynamic to preserve caller-saved registers
[not found] ` <CAFUsyfLxWY_0mOsHar42A4OpDocZP=ea6ChjD-9Ae49Nh2Z_1g@mail.gmail.com>
@ 2024-03-08 20:10 ` H.J. Lu
0 siblings, 0 replies; only message in thread
From: H.J. Lu @ 2024-03-08 20:10 UTC (permalink / raw)
To: Noah Goldstein, Florian Weimer, Sunil K Pandey, Libc-stable Mailing List
Cc: libc-alpha, adhemerval.zanella
On Tue, Feb 27, 2024 at 9:00 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> On Mon, Feb 26, 2024 at 1:06 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > On Mon, Feb 26, 2024 at 11:02 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> > >
> > > On Mon, Feb 26, 2024 at 1:02 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> > > >
> > > > On Mon, Feb 26, 2024 at 8:37 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> > > > >
> > > > > Compiler generates the following instruction sequence for GNU2 dynamic
> > > > > TLS access:
> > > > >
> > > > > leaq tls_var@TLSDESC(%rip), %rax
> > > > > call *tls_var@TLSCALL(%rax)
> > > > >
> > > > > or
> > > > >
> > > > > leal tls_var@TLSDESC(%ebx), %eax
> > > > > call *tls_var@TLSCALL(%eax)
> > > > >
> > > > > CALL instruction is transparent to compiler which assumes all registers,
> > > > > except for EFLAGS and RAX/EAX, are unchanged after CALL. When
> > > > > _dl_tlsdesc_dynamic is called, it calls __tls_get_addr on the slow
> > > > > path. __tls_get_addr is a normal function which doesn't preserve any
> > > > > caller-saved registers. _dl_tlsdesc_dynamic saved and restored integer
> > > > > caller-saved registers, but didn't preserve any other caller-saved
> > > > > registers. Add _dl_tlsdesc_dynamic IFUNC functions for FNSAVE, FXSAVE,
> > > > > XSAVE and XSAVEC to save and restore all caller-saved registers. This
> > > > > fixes BZ #31372.
> > > > >
> > > > > Add GLRO(dl_x86_64_runtime_resolve) with GLRO(dl_x86_tlsdesc_dynamic)
> > > > > to optimize elf_machine_runtime_setup.
> > > > > ---
> > > > > elf/Makefile | 18 ++
> > > > > elf/tst-gnu2-tls2.c | 122 ++++++++++++
> > > > > elf/tst-gnu2-tls2.h | 36 ++++
> > > > > elf/tst-gnu2-tls2mod0.c | 31 +++
> > > > > elf/tst-gnu2-tls2mod1.c | 31 +++
> > > > > elf/tst-gnu2-tls2mod2.c | 31 +++
> > > > > sysdeps/i386/dl-machine.h | 2 +-
> > > > > sysdeps/i386/dl-tlsdesc-dynamic.h | 190 +++++++++++++++++++
> > > > > sysdeps/i386/dl-tlsdesc.S | 115 +++++------
> > > > > sysdeps/x86/Makefile | 7 +-
> > > > > sysdeps/x86/cpu-features.c | 56 +++++-
> > > > > sysdeps/x86/dl-procinfo.c | 16 ++
> > > > > sysdeps/{x86_64 => x86}/features-offsets.sym | 2 +
> > > > > sysdeps/x86/sysdep.h | 6 +
> > > > > sysdeps/x86/tst-gnu2-tls2.c | 20 ++
> > > > > sysdeps/x86_64/Makefile | 2 +-
> > > > > sysdeps/x86_64/dl-machine.h | 19 +-
> > > > > sysdeps/x86_64/dl-procinfo.c | 16 ++
> > > > > sysdeps/x86_64/dl-tlsdesc-dynamic.h | 166 ++++++++++++++++
> > > > > sysdeps/x86_64/dl-tlsdesc.S | 108 ++++-------
> > > > > sysdeps/x86_64/dl-trampoline-save.h | 34 ++++
> > > > > sysdeps/x86_64/dl-trampoline-state.h | 51 +++++
> > > > > sysdeps/x86_64/dl-trampoline.S | 20 +-
> > > > > sysdeps/x86_64/dl-trampoline.h | 34 +---
> > > > > 24 files changed, 920 insertions(+), 213 deletions(-)
> > > > > create mode 100644 elf/tst-gnu2-tls2.c
> > > > > create mode 100644 elf/tst-gnu2-tls2.h
> > > > > create mode 100644 elf/tst-gnu2-tls2mod0.c
> > > > > create mode 100644 elf/tst-gnu2-tls2mod1.c
> > > > > create mode 100644 elf/tst-gnu2-tls2mod2.c
> > > > > create mode 100644 sysdeps/i386/dl-tlsdesc-dynamic.h
> > > > > rename sysdeps/{x86_64 => x86}/features-offsets.sym (89%)
> > > > > create mode 100644 sysdeps/x86/tst-gnu2-tls2.c
> > > > > create mode 100644 sysdeps/x86_64/dl-tlsdesc-dynamic.h
> > > > > create mode 100644 sysdeps/x86_64/dl-trampoline-save.h
> > > > > create mode 100644 sysdeps/x86_64/dl-trampoline-state.h
> > > > >
> > > > > diff --git a/elf/Makefile b/elf/Makefile
> > > > > index 36c04baf02..02dc476e27 100644
> > > > > --- a/elf/Makefile
> > > > > +++ b/elf/Makefile
> > > > > @@ -424,6 +424,7 @@ tests += \
> > > > > tst-glibc-hwcaps-prepend \
> > > > > tst-global1 \
> > > > > tst-global2 \
> > > > > + tst-gnu2-tls2 \
> > > > > tst-initfinilazyfail \
> > > > > tst-initorder \
> > > > > tst-initorder2 \
> > > > > @@ -846,6 +847,9 @@ modules-names += \
> > > > > tst-filterobj-flt \
> > > > > tst-finilazyfailmod \
> > > > > tst-globalmod2 \
> > > > > + tst-gnu2-tls2mod0 \
> > > > > + tst-gnu2-tls2mod1 \
> > > > > + tst-gnu2-tls2mod2 \
> > > > > tst-initlazyfailmod \
> > > > > tst-initorder2a \
> > > > > tst-initorder2b \
> > > > > @@ -3044,8 +3048,22 @@ $(objpfx)tst-tlsgap.out: \
> > > > > $(objpfx)tst-tlsgap-mod0.so \
> > > > > $(objpfx)tst-tlsgap-mod1.so \
> > > > > $(objpfx)tst-tlsgap-mod2.so
> > > > > +
> > > > > +$(objpfx)tst-gnu2-tls2: $(shared-thread-library)
> > > > > +$(objpfx)tst-gnu2-tls2.out: \
> > > > > + $(objpfx)tst-gnu2-tls2mod0.so \
> > > > > + $(objpfx)tst-gnu2-tls2mod1.so \
> > > > > + $(objpfx)tst-gnu2-tls2mod2.so
> > > > > +
> > > > > ifeq (yes,$(have-mtls-dialect-gnu2))
> > > > > +# This test fails if dl_tlsdesc_dynamic doesn't preserve all caller-saved
> > > > > +# registers. See https://sourceware.org/bugzilla/show_bug.cgi?id=31372
> > > > > +test-xfail-tst-gnu2-tls2 = yes
> > > > > +
> > > > > CFLAGS-tst-tlsgap-mod0.c += -mtls-dialect=gnu2
> > > > > CFLAGS-tst-tlsgap-mod1.c += -mtls-dialect=gnu2
> > > > > CFLAGS-tst-tlsgap-mod2.c += -mtls-dialect=gnu2
> > > > > +CFLAGS-tst-gnu2-tls2mod0.c += -mtls-dialect=gnu2
> > > > > +CFLAGS-tst-gnu2-tls2mod1.c += -mtls-dialect=gnu2
> > > > > +CFLAGS-tst-gnu2-tls2mod2.c += -mtls-dialect=gnu2
> > > > > endif
> > > > > diff --git a/elf/tst-gnu2-tls2.c b/elf/tst-gnu2-tls2.c
> > > > > new file mode 100644
> > > > > index 0000000000..7ac04d7f33
> > > > > --- /dev/null
> > > > > +++ b/elf/tst-gnu2-tls2.c
> > > > > @@ -0,0 +1,122 @@
> > > > > +/* Test TLSDESC relocation.
> > > > > + Copyright (C) 2024 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
> > > > > + <http://www.gnu.org/licenses/>. */
> > > > > +
> > > > > +#include <stdio.h>
> > > > > +#include <stdlib.h>
> > > > > +#include <string.h>
> > > > > +#include <dlfcn.h>
> > > > > +#include <pthread.h>
> > > > > +#include <support/xdlfcn.h>
> > > > > +#include <support/xthread.h>
> > > > > +#include <support/check.h>
> > > > > +#include <support/test-driver.h>
> > > > > +#include "tst-gnu2-tls2.h"
> > > > > +
> > > > > +#ifndef IS_SUPPORTED
> > > > > +# define IS_SUPPORTED() true
> > > > > +#endif
> > > > > +
> > > > > +/* An architecture can define it to clobber caller-saved registers in
> > > > > + malloc below to verify that the implicit TLSDESC call won't change
> > > > > + caller-saved registers. */
> > > > > +#ifndef PREPARE_MALLOC
> > > > > +# define PREPARE_MALLOC()
> > > > > +#endif
> > > > > +
> > > > > +extern void * __libc_malloc (size_t);
> > > > > +
> > > > > +size_t malloc_counter = 0;
> > > > > +
> > > > > +void *
> > > > > +malloc (size_t n)
> > > > > +{
> > > > > + PREPARE_MALLOC ();
> > > > > + malloc_counter++;
> > > > > + return __libc_malloc (n);
> > > > > +}
> > > > > +
> > > > > +static void *mod[3];
> > > > > +#ifndef MOD
> > > > > +# define MOD(i) "tst-gnu2-tls2mod" #i ".so"
> > > > > +#endif
> > > > > +static const char *modname[3] = { MOD(0), MOD(1), MOD(2) };
> > > > > +#undef MOD
> > > > > +
> > > > > +static void
> > > > > +open_mod (int i)
> > > > > +{
> > > > > + mod[i] = xdlopen (modname[i], RTLD_LAZY);
> > > > > + printf ("open %s\n", modname[i]);
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +close_mod (int i)
> > > > > +{
> > > > > + xdlclose (mod[i]);
> > > > > + mod[i] = NULL;
> > > > > + printf ("close %s\n", modname[i]);
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +access_mod (int i, const char *sym)
> > > > > +{
> > > > > + struct tls var = { -1, -1, -1, -1 };
> > > > > + struct tls *(*f) (struct tls *) = xdlsym (mod[i], sym);
> > > > > + /* Check that our malloc is called. */
> > > > > + malloc_counter = 0;
> > > > > + struct tls *p = f (&var);
> > > > > + TEST_VERIFY (malloc_counter != 0);
> > > > > + printf ("access %s: %s() = %p\n", modname[i], sym, p);
> > > > > + TEST_VERIFY_EXIT (memcmp (p, &var, sizeof (var)) == 0);
> > > > > + ++(p->a);
> > > > > +}
> > > > > +
> > > > > +static void *
> > > > > +start (void *arg)
> > > > > +{
> > > > > + /* The DTV generation is at the last dlopen of mod0 and the
> > > > > + entry for mod1 is NULL. */
> > > > > +
> > > > > + open_mod (1); /* Reuse modid of mod1. Uses dynamic TLS. */
> > > > > +
> > > > > + /* Force the slow path in GNU2 TLS descriptor call. */
> > > > > + access_mod (1, "apply_tls");
> > > > > +
> > > > > + return arg;
> > > > > +}
> > > > > +
> > > > > +static int
> > > > > +do_test (void)
> > > > > +{
> > > > > + if (!IS_SUPPORTED ())
> > > > > + return EXIT_UNSUPPORTED;
> > > > > +
> > > > > + open_mod (0);
> > > > > + open_mod (1);
> > > > > + open_mod (2);
> > > > > + close_mod (0);
> > > > > + close_mod (1); /* Create modid gap at mod1. */
> > > > > + open_mod (0); /* Reuse modid of mod0, bump generation count. */
> > > > > +
> > > > > + /* Create a thread where DTV of mod1 is NULL. */
> > > > > + pthread_t t = xpthread_create (NULL, start, NULL);
> > > > > + xpthread_join (t);
> > > > > + return 0;
> > > > > +}
> > > > > +
> > > > > +#include <support/test-driver.c>
> > > > > diff --git a/elf/tst-gnu2-tls2.h b/elf/tst-gnu2-tls2.h
> > > > > new file mode 100644
> > > > > index 0000000000..77964a57a3
> > > > > --- /dev/null
> > > > > +++ b/elf/tst-gnu2-tls2.h
> > > > > @@ -0,0 +1,36 @@
> > > > > +/* Test TLSDESC relocation.
> > > > > + Copyright (C) 2024 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 <stdint.h>
> > > > > +
> > > > > +struct tls
> > > > > +{
> > > > > + int64_t a, b, c, d;
> > > > > +};
> > > > > +
> > > > > +extern struct tls *apply_tls (struct tls *);
> > > > > +
> > > > > +/* An architecture can define them to verify that clobber caller-saved
> > > > > + registers aren't changed by the implicit TLSDESC call. */
> > > > > +#ifndef BEFORE_TLSDESC_CALL
> > > > > +# define BEFORE_TLSDESC_CALL()
> > > > > +#endif
> > > > > +
> > > > > +#ifndef AFTER_TLSDESC_CALL
> > > > > +# define AFTER_TLSDESC_CALL()
> > > > > +#endif
> > > > > diff --git a/elf/tst-gnu2-tls2mod0.c b/elf/tst-gnu2-tls2mod0.c
> > > > > new file mode 100644
> > > > > index 0000000000..45556a0e17
> > > > > --- /dev/null
> > > > > +++ b/elf/tst-gnu2-tls2mod0.c
> > > > > @@ -0,0 +1,31 @@
> > > > > +/* DSO used by tst-gnu2-tls2.
> > > > > + Copyright (C) 2024 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 "tst-gnu2-tls2.h"
> > > > > +
> > > > > +__thread struct tls tls_var0 __attribute__ ((visibility ("hidden")));
> > > > > +
> > > > > +struct tls *
> > > > > +apply_tls (struct tls *p)
> > > > > +{
> > > > > + BEFORE_TLSDESC_CALL ();
> > > > > + tls_var0 = *p;
> > > > > + struct tls *ret = &tls_var0;
> > > > > + AFTER_TLSDESC_CALL ();
> > > > > + return ret;
> > > > > +}
> > > > > diff --git a/elf/tst-gnu2-tls2mod1.c b/elf/tst-gnu2-tls2mod1.c
> > > > > new file mode 100644
> > > > > index 0000000000..e10b9dbc0a
> > > > > --- /dev/null
> > > > > +++ b/elf/tst-gnu2-tls2mod1.c
> > > > > @@ -0,0 +1,31 @@
> > > > > +/* DSO used by tst-gnu2-tls2.
> > > > > + Copyright (C) 2024 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 "tst-gnu2-tls2.h"
> > > > > +
> > > > > +__thread struct tls tls_var1[100] __attribute__ ((visibility ("hidden")));
> > > > > +
> > > > > +struct tls *
> > > > > +apply_tls (struct tls *p)
> > > > > +{
> > > > > + BEFORE_TLSDESC_CALL ();
> > > > > + tls_var1[1] = *p;
> > > > > + struct tls *ret = &tls_var1[1];
> > > > > + AFTER_TLSDESC_CALL ();
> > > > > + return ret;
> > > > > +}
> > > > > diff --git a/elf/tst-gnu2-tls2mod2.c b/elf/tst-gnu2-tls2mod2.c
> > > > > new file mode 100644
> > > > > index 0000000000..141af51e55
> > > > > --- /dev/null
> > > > > +++ b/elf/tst-gnu2-tls2mod2.c
> > > > > @@ -0,0 +1,31 @@
> > > > > +/* DSO used by tst-gnu2-tls2.
> > > > > + Copyright (C) 2024 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 "tst-gnu2-tls2.h"
> > > > > +
> > > > > +__thread struct tls tls_var2 __attribute__ ((visibility ("hidden")));
> > > > > +
> > > > > +struct tls *
> > > > > +apply_tls (struct tls *p)
> > > > > +{
> > > > > + BEFORE_TLSDESC_CALL ();
> > > > > + tls_var2 = *p;
> > > > > + struct tls *ret = &tls_var2;
> > > > > + AFTER_TLSDESC_CALL ();
> > > > > + return ret;
> > > > > +}
> > > > > diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
> > > > > index fc1ef96587..50d74fe6e9 100644
> > > > > --- a/sysdeps/i386/dl-machine.h
> > > > > +++ b/sysdeps/i386/dl-machine.h
> > > > > @@ -347,7 +347,7 @@ and creates an unsatisfiable circular dependency.\n",
> > > > > {
> > > > > td->arg = _dl_make_tlsdesc_dynamic
> > > > > (sym_map, sym->st_value + (ElfW(Word))td->arg);
> > > > > - td->entry = _dl_tlsdesc_dynamic;
> > > > > + td->entry = GLRO(dl_x86_tlsdesc_dynamic);
> > > > > }
> > > > > else
> > > > > # endif
> > > > > diff --git a/sysdeps/i386/dl-tlsdesc-dynamic.h b/sysdeps/i386/dl-tlsdesc-dynamic.h
> > > > > new file mode 100644
> > > > > index 0000000000..3627028577
> > > > > --- /dev/null
> > > > > +++ b/sysdeps/i386/dl-tlsdesc-dynamic.h
> > > > > @@ -0,0 +1,190 @@
> > > > > +/* Thread-local storage handling in the ELF dynamic linker. i386 version.
> > > > > + Copyright (C) 2004-2024 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/>. */
> > > > > +
> > > > > +#undef REGISTER_SAVE_AREA
> > > > > +
> > > > > +#if !defined USE_FNSAVE && (STATE_SAVE_ALIGNMENT % 16) != 0
> > > > > +# error STATE_SAVE_ALIGNMENT must be multiple of 16
> > > > > +#endif
> > > > > +
> > > > > +#if DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > +# ifdef USE_FNSAVE
> > > > > +# error USE_FNSAVE shouldn't be defined
> > > > > +# endif
> > > > > +# ifdef USE_FXSAVE
> > > > > +/* Use fxsave to save all registers. */
> > > > > +# define REGISTER_SAVE_AREA 512
> > > > > +# endif
> > > > > +#else
> > > > > +# ifdef USE_FNSAVE
> > > > > +/* Use fnsave to save x87 FPU stack registers. */
> > > > > +# define REGISTER_SAVE_AREA 108
> > > > > +# else
> > > > > +# ifndef USE_FXSAVE
> > > > > +# error USE_FXSAVE must be defined
> > > > > +# endif
> > > > > +/* Use fxsave to save all registers. Add 12 bytes to align the stack
> > > > > + to 16 bytes. */
> > > > > +# define REGISTER_SAVE_AREA (512 + 12)
> > > > > +# endif
> > > > > +#endif
> > > > > +
> > > > > + .hidden _dl_tlsdesc_dynamic
> > > > > + .global _dl_tlsdesc_dynamic
> > > > > + .type _dl_tlsdesc_dynamic,@function
> > > > > +
> > > > > + /* This function is used for symbols that need dynamic TLS.
> > > > > +
> > > > > + %eax points to the TLS descriptor, such that 0(%eax) points to
> > > > > + _dl_tlsdesc_dynamic itself, and 4(%eax) points to a struct
> > > > > + tlsdesc_dynamic_arg object. It must return in %eax the offset
> > > > > + between the thread pointer and the object denoted by the
> > > > > + argument, without clobbering any registers.
> > > > > +
> > > > > + The assembly code that follows is a rendition of the following
> > > > > + C code, hand-optimized a little bit.
> > > > > +
> > > > > +ptrdiff_t
> > > > > +__attribute__ ((__regparm__ (1)))
> > > > > +_dl_tlsdesc_dynamic (struct tlsdesc *tdp)
> > > > > +{
> > > > > + struct tlsdesc_dynamic_arg *td = tdp->arg;
> > > > > + dtv_t *dtv = *(dtv_t **)((char *)__thread_pointer + DTV_OFFSET);
> > > > > + if (__builtin_expect (td->gen_count <= dtv[0].counter
> > > > > + && (dtv[td->tlsinfo.ti_module].pointer.val
> > > > > + != TLS_DTV_UNALLOCATED),
> > > > > + 1))
> > > > > + return dtv[td->tlsinfo.ti_module].pointer.val + td->tlsinfo.ti_offset
> > > > > + - __thread_pointer;
> > > > > +
> > > > > + return ___tls_get_addr (&td->tlsinfo) - __thread_pointer;
> > > > > +}
> > > > > +*/
> > > > > + cfi_startproc
> > > > > + .align 16
> > > > > +_dl_tlsdesc_dynamic:
> > > > > + /* Like all TLS resolvers, preserve call-clobbered registers.
> > > > > + We need two scratch regs anyway. */
> > > > > + subl $32, %esp
> > > > > + cfi_adjust_cfa_offset (32)
> > > > > + movl %ecx, 20(%esp)
> > > > > + movl %edx, 24(%esp)
> > > > > + movl TLSDESC_ARG(%eax), %eax
> > > > > + movl %gs:DTV_OFFSET, %edx
> > > > > + movl TLSDESC_GEN_COUNT(%eax), %ecx
> > > > > + cmpl (%edx), %ecx
> > > > > + ja 2f
> > > > > + movl TLSDESC_MODID(%eax), %ecx
> > > > > + movl (%edx,%ecx,8), %edx
> > > > > + cmpl $-1, %edx
> > > > > + je 2f
> > > > > + movl TLSDESC_MODOFF(%eax), %eax
> > > > > + addl %edx, %eax
> > > > > +1:
> > > > > + movl 20(%esp), %ecx
> > > > > + subl %gs:0, %eax
> > > > > + movl 24(%esp), %edx
> > > > > + addl $32, %esp
> > > > > + cfi_adjust_cfa_offset (-32)
> > > > > + ret
> > > > > + .p2align 4,,7
> > > > > +2:
> > > > > + cfi_adjust_cfa_offset (32)
> > > > > +#if DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > + movl %ebx, -28(%esp)
> > > > > + movl %esp, %ebx
> > > > > + cfi_def_cfa_register(%ebx)
> > > > > + and $-STATE_SAVE_ALIGNMENT, %esp
> > > > > +#endif
> > > > > +#ifdef REGISTER_SAVE_AREA
> > > > > + subl $REGISTER_SAVE_AREA, %esp
> > > > > +# if !DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > + cfi_adjust_cfa_offset(REGISTER_SAVE_AREA)
> > > > > +# endif
> > > > > +#else
> > > > > +# if !DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > +# error DL_RUNTIME_RESOLVE_REALIGN_STACK must be true
> > > > > +# endif
> > > > > + /* Allocate stack space of the required size to save the state. */
> > > > > + LOAD_PIC_REG (cx)
> > > > > + subl RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET+XSAVE_STATE_SIZE_OFFSET+_rtld_local_ro@GOTOFF(%ecx), %esp
> > > > > +#endif
> > > > > +#ifdef USE_FNSAVE
> > > > > + fnsave (%esp)
> > > > > +#elif defined USE_FXSAVE
> > > > > + fxsave (%esp)
> > > > > +#else
> > > > > + /* Save the argument for ___tls_get_addr in EAX. */
> > > > > + movl %eax, %ecx
> > > > > + movl $TLSDESC_CALL_STATE_SAVE_MASK, %eax
> > > > > + xorl %edx, %edx
> > > > > + /* Clear the XSAVE Header. */
> > > > > +# ifdef USE_XSAVE
> > > > > + movl %edx, (512)(%esp)
> > > > > + movl %edx, (512 + 4 * 1)(%esp)
> > > > > + movl %edx, (512 + 4 * 2)(%esp)
> > > > > + movl %edx, (512 + 4 * 3)(%esp)
> > > > > +# endif
> > > > > + movl %edx, (512 + 4 * 4)(%esp)
> > > > > + movl %edx, (512 + 4 * 5)(%esp)
> > > > > + movl %edx, (512 + 4 * 6)(%esp)
> > > > > + movl %edx, (512 + 4 * 7)(%esp)
> > > > > + movl %edx, (512 + 4 * 8)(%esp)
> > > > > + movl %edx, (512 + 4 * 9)(%esp)
> > > > > + movl %edx, (512 + 4 * 10)(%esp)
> > > > > + movl %edx, (512 + 4 * 11)(%esp)
> > > > > + movl %edx, (512 + 4 * 12)(%esp)
> > > > > + movl %edx, (512 + 4 * 13)(%esp)
> > > > > + movl %edx, (512 + 4 * 14)(%esp)
> > > > > + movl %edx, (512 + 4 * 15)(%esp)
> > > > > +# ifdef USE_XSAVE
> > > > > + xsave (%esp)
> > > > > +# else
> > > > > + xsavec (%esp)
> > > > > +# endif
> > > > > + /* Restore the argument for ___tls_get_addr in EAX. */
> > > > > + movl %ecx, %eax
> > > > > +#endif
> > > > > + call HIDDEN_JUMPTARGET (___tls_get_addr)
> > > > > + /* Get register content back. */
> > > > > +#ifdef USE_FNSAVE
> > > > > + frstor (%esp)
> > > > > +#elif defined USE_FXSAVE
> > > > > + fxrstor (%esp)
> > > > > +#else
> > > > > + /* Save and retore ___tls_get_addr return value stored in EAX. */
> > > > > + movl %eax, %ecx
> > > > > + movl $TLSDESC_CALL_STATE_SAVE_MASK, %eax
> > > > > + xorl %edx, %edx
> > > > > + xrstor (%esp)
> > > > > + movl %ecx, %eax
> > > > > +#endif
> > > > > +#if DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > + mov %ebx, %esp
> > > > > + cfi_def_cfa_register(%esp)
> > > > > + movl -28(%esp), %ebx
> > > > > + cfi_restore(%ebx)
> > > > > +#else
> > > > > + addl $REGISTER_SAVE_AREA, %esp
> > > > > + cfi_adjust_cfa_offset(-REGISTER_SAVE_AREA)
> > > > > +#endif
> > > > > + jmp 1b
> > > > > + cfi_endproc
> > > > > + .size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic
> > > > > +
> > > > > +#undef STATE_SAVE_ALIGNMENT
> > > > > diff --git a/sysdeps/i386/dl-tlsdesc.S b/sysdeps/i386/dl-tlsdesc.S
> > > > > index 90d93caa0c..f002feee56 100644
> > > > > --- a/sysdeps/i386/dl-tlsdesc.S
> > > > > +++ b/sysdeps/i386/dl-tlsdesc.S
> > > > > @@ -18,8 +18,27 @@
> > > > >
> > > > > #include <sysdep.h>
> > > > > #include <tls.h>
> > > > > +#include <cpu-features-offsets.h>
> > > > > +#include <features-offsets.h>
> > > > > #include "tlsdesc.h"
> > > > >
> > > > > +#ifndef DL_STACK_ALIGNMENT
> > > > > +/* Due to GCC bug:
> > > > > +
> > > > > + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
> > > > > +
> > > > > + __tls_get_addr may be called with 4-byte stack alignment. Although
> > > > > + this bug has been fixed in GCC 4.9.4, 5.3 and 6, we can't assume
> > > > > + that stack will be always aligned at 16 bytes. */
> > > > > +# define DL_STACK_ALIGNMENT 4
> > > > > +#endif
> > > > > +
> > > > > +/* True if _dl_tlsdesc_dynamic should align stack for STATE_SAVE or align
> > > > > + stack to MINIMUM_ALIGNMENT bytes before calling ___tls_get_addr. */
> > > > > +#define DL_RUNTIME_RESOLVE_REALIGN_STACK \
> > > > > + (STATE_SAVE_ALIGNMENT > DL_STACK_ALIGNMENT \
> > > > > + || MINIMUM_ALIGNMENT > DL_STACK_ALIGNMENT)
> > > > > +
> > > > > .text
> > > > >
> > > > > /* This function is used to compute the TP offset for symbols in
> > > > > @@ -65,69 +84,35 @@ _dl_tlsdesc_undefweak:
> > > > > .size _dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak
> > > > >
> > > > > #ifdef SHARED
> > > > > - .hidden _dl_tlsdesc_dynamic
> > > > > - .global _dl_tlsdesc_dynamic
> > > > > - .type _dl_tlsdesc_dynamic,@function
> > > > > -
> > > > > - /* This function is used for symbols that need dynamic TLS.
> > > > > -
> > > > > - %eax points to the TLS descriptor, such that 0(%eax) points to
> > > > > - _dl_tlsdesc_dynamic itself, and 4(%eax) points to a struct
> > > > > - tlsdesc_dynamic_arg object. It must return in %eax the offset
> > > > > - between the thread pointer and the object denoted by the
> > > > > - argument, without clobbering any registers.
> > > > > -
> > > > > - The assembly code that follows is a rendition of the following
> > > > > - C code, hand-optimized a little bit.
> > > > > -
> > > > > -ptrdiff_t
> > > > > -__attribute__ ((__regparm__ (1)))
> > > > > -_dl_tlsdesc_dynamic (struct tlsdesc *tdp)
> > > > > -{
> > > > > - struct tlsdesc_dynamic_arg *td = tdp->arg;
> > > > > - dtv_t *dtv = *(dtv_t **)((char *)__thread_pointer + DTV_OFFSET);
> > > > > - if (__builtin_expect (td->gen_count <= dtv[0].counter
> > > > > - && (dtv[td->tlsinfo.ti_module].pointer.val
> > > > > - != TLS_DTV_UNALLOCATED),
> > > > > - 1))
> > > > > - return dtv[td->tlsinfo.ti_module].pointer.val + td->tlsinfo.ti_offset
> > > > > - - __thread_pointer;
> > > > > -
> > > > > - return ___tls_get_addr (&td->tlsinfo) - __thread_pointer;
> > > > > -}
> > > > > -*/
> > > > > - cfi_startproc
> > > > > - .align 16
> > > > > -_dl_tlsdesc_dynamic:
> > > > > - /* Like all TLS resolvers, preserve call-clobbered registers.
> > > > > - We need two scratch regs anyway. */
> > > > > - subl $28, %esp
> > > > > - cfi_adjust_cfa_offset (28)
> > > > > - movl %ecx, 20(%esp)
> > > > > - movl %edx, 24(%esp)
> > > > > - movl TLSDESC_ARG(%eax), %eax
> > > > > - movl %gs:DTV_OFFSET, %edx
> > > > > - movl TLSDESC_GEN_COUNT(%eax), %ecx
> > > > > - cmpl (%edx), %ecx
> > > > > - ja .Lslow
> > > > > - movl TLSDESC_MODID(%eax), %ecx
> > > > > - movl (%edx,%ecx,8), %edx
> > > > > - cmpl $-1, %edx
> > > > > - je .Lslow
> > > > > - movl TLSDESC_MODOFF(%eax), %eax
> > > > > - addl %edx, %eax
> > > > > -.Lret:
> > > > > - movl 20(%esp), %ecx
> > > > > - subl %gs:0, %eax
> > > > > - movl 24(%esp), %edx
> > > > > - addl $28, %esp
> > > > > - cfi_adjust_cfa_offset (-28)
> > > > > - ret
> > > > > - .p2align 4,,7
> > > > > -.Lslow:
> > > > > - cfi_adjust_cfa_offset (28)
> > > > > - call HIDDEN_JUMPTARGET (___tls_get_addr)
> > > > > - jmp .Lret
> > > > > - cfi_endproc
> > > > > - .size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic
> > > > > +# define USE_FNSAVE
> > > > > +# define MINIMUM_ALIGNMENT 4
> > > > > +# define STATE_SAVE_ALIGNMENT 4
> > > > > +# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_fnsave
> > > > > +# include "dl-tlsdesc-dynamic.h"
> > > > > +# undef _dl_tlsdesc_dynamic
> > > > > +# undef MINIMUM_ALIGNMENT
> > > > > +# undef USE_FNSAVE
> > > > > +
> > > > > +# define MINIMUM_ALIGNMENT 16
> > > > > +
> > > > > +# define USE_FXSAVE
> > > > > +# define STATE_SAVE_ALIGNMENT 16
> > > > > +# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_fxsave
> > > > > +# include "dl-tlsdesc-dynamic.h"
> > > > > +# undef _dl_tlsdesc_dynamic
> > > > > +# undef USE_FXSAVE
> > > > > +
> > > > > +# define USE_XSAVE
> > > > > +# define STATE_SAVE_ALIGNMENT 64
> > > > > +# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_xsave
> > > > > +# include "dl-tlsdesc-dynamic.h"
> > > > > +# undef _dl_tlsdesc_dynamic
> > > > > +# undef USE_XSAVE
> > > > > +
> > > > > +# define USE_XSAVEC
> > > > > +# define STATE_SAVE_ALIGNMENT 64
> > > > > +# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_xsavec
> > > > > +# include "dl-tlsdesc-dynamic.h"
> > > > > +# undef _dl_tlsdesc_dynamic
> > > > > +# undef USE_XSAVEC
> > > > > #endif /* SHARED */
> > > > > diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
> > > > > index 73b29cc78c..5311b594af 100644
> > > > > --- a/sysdeps/x86/Makefile
> > > > > +++ b/sysdeps/x86/Makefile
> > > > > @@ -1,5 +1,5 @@
> > > > > ifeq ($(subdir),csu)
> > > > > -gen-as-const-headers += cpu-features-offsets.sym
> > > > > +gen-as-const-headers += cpu-features-offsets.sym features-offsets.sym
> > > > > endif
> > > > >
> > > > > ifeq ($(subdir),elf)
> > > > > @@ -86,6 +86,11 @@ endif
> > > > > tst-ifunc-isa-2-ENV = GLIBC_TUNABLES=glibc.cpu.hwcaps=-SSE4_2,-AVX,-AVX2,-AVX512F
> > > > > tst-ifunc-isa-2-static-ENV = $(tst-ifunc-isa-2-ENV)
> > > > > tst-hwcap-tunables-ARGS = -- $(host-test-program-cmd)
> > > > > +
> > > > > +CFLAGS-tst-gnu2-tls2.c += -msse
> > > > > +CFLAGS-tst-gnu2-tls2mod0.c += -msse2 -mtune=haswell
> > > > > +CFLAGS-tst-gnu2-tls2mod1.c += -msse2 -mtune=haswell
> > > > > +CFLAGS-tst-gnu2-tls2mod2.c += -msse2 -mtune=haswell
> > > > > endif
> > > > >
> > > > > ifeq ($(subdir),math)
> > > > > diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
> > > > > index 25e6622a79..835113b42f 100644
> > > > > --- a/sysdeps/x86/cpu-features.c
> > > > > +++ b/sysdeps/x86/cpu-features.c
> > > > > @@ -27,8 +27,13 @@
> > > > > extern void TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *)
> > > > > attribute_hidden;
> > > > >
> > > > > -#if defined SHARED && defined __x86_64__
> > > > > -# include <dl-plt-rewrite.h>
> > > > > +#if defined SHARED
> > > > > +extern void _dl_tlsdesc_dynamic_fxsave (void) attribute_hidden;
> > > > > +extern void _dl_tlsdesc_dynamic_xsave (void) attribute_hidden;
> > > > > +extern void _dl_tlsdesc_dynamic_xsavec (void) attribute_hidden;
> > > > > +
> > > > > +# ifdef __x86_64__
> > > > > +# include <dl-plt-rewrite.h>
> > > > >
> > > > > static void
> > > > > TUNABLE_CALLBACK (set_plt_rewrite) (tunable_val_t *valp)
> > > > > @@ -47,6 +52,15 @@ TUNABLE_CALLBACK (set_plt_rewrite) (tunable_val_t *valp)
> > > > > : plt_rewrite_jmp);
> > > > > }
> > > > > }
> > > > > +# else
> > > > > +extern void _dl_tlsdesc_dynamic_fnsave (void) attribute_hidden;
> > > > > +# endif
> > > > > +#endif
> > > > > +
> > > > > +#ifdef __x86_64__
> > > > > +extern void _dl_runtime_resolve_fxsave (void) attribute_hidden;
> > > > > +extern void _dl_runtime_resolve_xsave (void) attribute_hidden;
> > > > > +extern void _dl_runtime_resolve_xsavec (void) attribute_hidden;
> > > > > #endif
> > > > >
> > > > > #ifdef __LP64__
> > > > > @@ -1130,6 +1144,44 @@ no_cpuid:
> > > > > TUNABLE_CALLBACK (set_x86_shstk));
> > > > > #endif
> > > > >
> > > > > + if (GLRO(dl_x86_cpu_features).xsave_state_size != 0)
> > > > > + {
> > > > > + if (CPU_FEATURE_USABLE_P (cpu_features, XSAVEC))
> > > > > + {
> > > > > +#ifdef __x86_64__
> > > > > + GLRO(dl_x86_64_runtime_resolve) = _dl_runtime_resolve_xsavec;
> > > > > +#endif
> > > > > +#ifdef SHARED
> > > > > + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_xsavec;
> > > > > +#endif
> > > > > + }
> > > > > + else
> > > > > + {
> > > > > +#ifdef __x86_64__
> > > > > + GLRO(dl_x86_64_runtime_resolve) = _dl_runtime_resolve_xsave;
> > > > > +#endif
> > > > > +#ifdef SHARED
> > > > > + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_xsave;
> > > > > +#endif
> > > > > + }
> > > > > + }
> > > > > + else
> > > > > + {
> > > > > +#ifdef __x86_64__
> > > > > + GLRO(dl_x86_64_runtime_resolve) = _dl_runtime_resolve_fxsave;
> > > > > +# ifdef SHARED
> > > > > + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_fxsave;
> > > > > +# endif
> > > > > +#else
> > > > > +# ifdef SHARED
> > > > > + if (CPU_FEATURE_USABLE_P (cpu_features, FXSR))
> > > > > + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_fxsave;
> > > > > + else
> > > > > + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_fnsave;
> > > > > +# endif
> > > > > +#endif
> > > > > + }
> > > > > +
> > > > > #ifdef SHARED
> > > > > # ifdef __x86_64__
> > > > > TUNABLE_GET (plt_rewrite, tunable_val_t *,
> > > > > diff --git a/sysdeps/x86/dl-procinfo.c b/sysdeps/x86/dl-procinfo.c
> > > > > index ee957b4d70..5920d4b320 100644
> > > > > --- a/sysdeps/x86/dl-procinfo.c
> > > > > +++ b/sysdeps/x86/dl-procinfo.c
> > > > > @@ -86,3 +86,19 @@ PROCINFO_CLASS const char _dl_x86_platforms[4][9]
> > > > > #else
> > > > > ,
> > > > > #endif
> > > > > +
> > > > > +#if defined SHARED && !IS_IN (ldconfig)
> > > > > +# if !defined PROCINFO_DECL
> > > > > + ._dl_x86_tlsdesc_dynamic
> > > > > +# else
> > > > > +PROCINFO_CLASS void * _dl_x86_tlsdesc_dynamic
> > > > > +# endif
> > > > > +# ifndef PROCINFO_DECL
> > > > > += NULL
> > > > > +# endif
> > > > > +# ifdef PROCINFO_DECL
> > > > > +;
> > > > > +# else
> > > > > +,
> > > > > +# endif
> > > > > +#endif
> > > > > diff --git a/sysdeps/x86_64/features-offsets.sym b/sysdeps/x86/features-offsets.sym
> > > > > similarity index 89%
> > > > > rename from sysdeps/x86_64/features-offsets.sym
> > > > > rename to sysdeps/x86/features-offsets.sym
> > > > > index 9e4be3393a..77e990c705 100644
> > > > > --- a/sysdeps/x86_64/features-offsets.sym
> > > > > +++ b/sysdeps/x86/features-offsets.sym
> > > > > @@ -3,4 +3,6 @@
> > > > > #include <ldsodefs.h>
> > > > >
> > > > > RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET offsetof (struct rtld_global_ro, _dl_x86_cpu_features)
> > > > > +#ifdef __x86_64__
> > > > > RTLD_GLOBAL_DL_X86_FEATURE_1_OFFSET offsetof (struct rtld_global, _dl_x86_feature_1)
> > > > > +#endif
> > > > > diff --git a/sysdeps/x86/sysdep.h b/sysdeps/x86/sysdep.h
> > > > > index 837fd28734..485cad9c02 100644
> > > > > --- a/sysdeps/x86/sysdep.h
> > > > > +++ b/sysdeps/x86/sysdep.h
> > > > > @@ -70,6 +70,12 @@
> > > > > | (1 << X86_XSTATE_ZMM_H_ID))
> > > > > #endif
> > > > >
> > > > > +/* States which should be saved for TLSDESC_CALL and TLS_DESC_CALL.
> > > > > + Compiler assumes that all registers, including x87 FPU stack registers,
> > > > > + are unchanged after CALL, except for EFLAGS and RAX/EAX. */
> > > > > +#define TLSDESC_CALL_STATE_SAVE_MASK \
> > > > > + (STATE_SAVE_MASK | (1 << X86_XSTATE_X87_ID))
> > > > > +
> > > > > /* Constants for bits in __x86_string_control: */
> > > > >
> > > > > /* Avoid short distance REP MOVSB. */
> > > > > diff --git a/sysdeps/x86/tst-gnu2-tls2.c b/sysdeps/x86/tst-gnu2-tls2.c
> > > > > new file mode 100644
> > > > > index 0000000000..de900a423b
> > > > > --- /dev/null
> > > > > +++ b/sysdeps/x86/tst-gnu2-tls2.c
> > > > > @@ -0,0 +1,20 @@
> > > > > +#ifndef __x86_64__
> > > > > +#include <sys/platform/x86.h>
> > > > > +
> > > > > +#define IS_SUPPORTED() CPU_FEATURE_ACTIVE (SSE2)
> > > > > +#endif
> > > > > +
> > > > > +/* Clear XMM0...XMM7 */
> > > > > +#define PREPARE_MALLOC() \
> > > > > +{ \
> > > > > + asm volatile ("xorps %%xmm0, %%xmm0" : : : "xmm0" ); \
> > > > > + asm volatile ("xorps %%xmm1, %%xmm1" : : : "xmm1" ); \
> > > > > + asm volatile ("xorps %%xmm2, %%xmm2" : : : "xmm2" ); \
> > > > > + asm volatile ("xorps %%xmm3, %%xmm3" : : : "xmm3" ); \
> > > > > + asm volatile ("xorps %%xmm4, %%xmm4" : : : "xmm4" ); \
> > > > > + asm volatile ("xorps %%xmm5, %%xmm5" : : : "xmm5" ); \
> > > > > + asm volatile ("xorps %%xmm6, %%xmm6" : : : "xmm6" ); \
> > > > > + asm volatile ("xorps %%xmm7, %%xmm7" : : : "xmm7" ); \
> > > > > +}
> > > > > +
> > > > > +#include <elf/tst-gnu2-tls2.c>
> > > > > diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
> > > > > index 145f25e7f6..9337e95093 100644
> > > > > --- a/sysdeps/x86_64/Makefile
> > > > > +++ b/sysdeps/x86_64/Makefile
> > > > > @@ -10,7 +10,7 @@ LDFLAGS-rtld += -Wl,-z,nomark-plt
> > > > > endif
> > > > >
> > > > > ifeq ($(subdir),csu)
> > > > > -gen-as-const-headers += features-offsets.sym link-defines.sym
> > > > > +gen-as-const-headers += link-defines.sym
> > > > > endif
> > > > >
> > > > > ifeq ($(subdir),gmon)
> > > > > diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h
> > > > > index 6d605d0d32..ff5d45f7cb 100644
> > > > > --- a/sysdeps/x86_64/dl-machine.h
> > > > > +++ b/sysdeps/x86_64/dl-machine.h
> > > > > @@ -71,9 +71,6 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
> > > > > int lazy, int profile)
> > > > > {
> > > > > Elf64_Addr *got;
> > > > > - extern void _dl_runtime_resolve_fxsave (ElfW(Word)) attribute_hidden;
> > > > > - extern void _dl_runtime_resolve_xsave (ElfW(Word)) attribute_hidden;
> > > > > - extern void _dl_runtime_resolve_xsavec (ElfW(Word)) attribute_hidden;
> > > > > extern void _dl_runtime_profile_sse (ElfW(Word)) attribute_hidden;
> > > > > extern void _dl_runtime_profile_avx (ElfW(Word)) attribute_hidden;
> > > > > extern void _dl_runtime_profile_avx512 (ElfW(Word)) attribute_hidden;
> > > > > @@ -96,8 +93,6 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
> > > > > /* Identify this shared object. */
> > > > > *(ElfW(Addr) *) (got + 1) = (ElfW(Addr)) l;
> > > > >
> > > > > - const struct cpu_features* cpu_features = __get_cpu_features ();
> > > > > -
> > > > > #ifdef SHARED
> > > > > /* The got[2] entry contains the address of a function which gets
> > > > > called to get the address of a so far unresolved function and
> > > > > @@ -107,6 +102,7 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
> > > > > end in this function. */
> > > > > if (__glibc_unlikely (profile))
> > > > > {
> > > > > + const struct cpu_features* cpu_features = __get_cpu_features ();
> > > > > if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512F))
> > > > > *(ElfW(Addr) *) (got + 2) = (ElfW(Addr)) &_dl_runtime_profile_avx512;
> > > > > else if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX))
> > > > > @@ -126,15 +122,8 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
> > > > > /* This function will get called to fix up the GOT entry
> > > > > indicated by the offset on the stack, and then jump to
> > > > > the resolved address. */
> > > > > - if (MINIMUM_X86_ISA_LEVEL >= AVX_X86_ISA_LEVEL
> > > > > - || GLRO(dl_x86_cpu_features).xsave_state_size != 0)
> > > > > - *(ElfW(Addr) *) (got + 2)
> > > > > - = (CPU_FEATURE_USABLE_P (cpu_features, XSAVEC)
> > > > > - ? (ElfW(Addr)) &_dl_runtime_resolve_xsavec
> > > > > - : (ElfW(Addr)) &_dl_runtime_resolve_xsave);
> > > > > - else
> > > > > - *(ElfW(Addr) *) (got + 2)
> > > > > - = (ElfW(Addr)) &_dl_runtime_resolve_fxsave;
> > > > > + *(ElfW(Addr) *) (got + 2)
> > > > > + = (ElfW(Addr)) GLRO(dl_x86_64_runtime_resolve);
> > > > > }
> > > > > }
> > > > >
> > > > > @@ -383,7 +372,7 @@ and creates an unsatisfiable circular dependency.\n",
> > > > > {
> > > > > td->arg = _dl_make_tlsdesc_dynamic
> > > > > (sym_map, sym->st_value + reloc->r_addend);
> > > > > - td->entry = _dl_tlsdesc_dynamic;
> > > > > + td->entry = GLRO(dl_x86_tlsdesc_dynamic);
> > > > > }
> > > > > else
> > > > > # endif
> > > > > diff --git a/sysdeps/x86_64/dl-procinfo.c b/sysdeps/x86_64/dl-procinfo.c
> > > > > index 4d1d790fbb..06637a8154 100644
> > > > > --- a/sysdeps/x86_64/dl-procinfo.c
> > > > > +++ b/sysdeps/x86_64/dl-procinfo.c
> > > > > @@ -41,5 +41,21 @@
> > > > >
> > > > > #include <sysdeps/x86/dl-procinfo.c>
> > > > >
> > > > > +#if !IS_IN (ldconfig)
> > > > > +# if !defined PROCINFO_DECL && defined SHARED
> > > > > + ._dl_x86_64_runtime_resolve
> > > > > +# else
> > > > > +PROCINFO_CLASS void * _dl_x86_64_runtime_resolve
> > > > > +# endif
> > > > > +# ifndef PROCINFO_DECL
> > > > > += NULL
> > > > > +# endif
> > > > > +# if !defined SHARED || defined PROCINFO_DECL
> > > > > +;
> > > > > +# else
> > > > > +,
> > > > > +# endif
> > > > > +#endif
> > > > > +
> > > > > #undef PROCINFO_DECL
> > > > > #undef PROCINFO_CLASS
> > > > > diff --git a/sysdeps/x86_64/dl-tlsdesc-dynamic.h b/sysdeps/x86_64/dl-tlsdesc-dynamic.h
> > > > > new file mode 100644
> > > > > index 0000000000..0c2e8d5320
> > > > > --- /dev/null
> > > > > +++ b/sysdeps/x86_64/dl-tlsdesc-dynamic.h
> > > > > @@ -0,0 +1,166 @@
> > > > > +/* Thread-local storage handling in the ELF dynamic linker. x86_64 version.
> > > > > + Copyright (C) 2004-2024 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 SECTION
> > > > > +# define SECTION(p) p
> > > > > +#endif
> > > > > +
> > > > > +#undef REGISTER_SAVE_AREA
> > > > > +#undef LOCAL_STORAGE_AREA
> > > > > +#undef BASE
> > > > > +
> > > > > +#include "dl-trampoline-state.h"
> > > > > +
> > > > > + .section SECTION(.text),"ax",@progbits
> > > > > +
> > > > > + .hidden _dl_tlsdesc_dynamic
> > > > > + .global _dl_tlsdesc_dynamic
> > > > > + .type _dl_tlsdesc_dynamic,@function
> > > > > +
> > > > > + /* %rax points to the TLS descriptor, such that 0(%rax) points to
> > > > > + _dl_tlsdesc_dynamic itself, and 8(%rax) points to a struct
> > > > > + tlsdesc_dynamic_arg object. It must return in %rax the offset
> > > > > + between the thread pointer and the object denoted by the
> > > > > + argument, without clobbering any registers.
> > > > > +
> > > > > + The assembly code that follows is a rendition of the following
> > > > > + C code, hand-optimized a little bit.
> > > > > +
> > > > > +ptrdiff_t
> > > > > +_dl_tlsdesc_dynamic (register struct tlsdesc *tdp asm ("%rax"))
> > > > > +{
> > > > > + struct tlsdesc_dynamic_arg *td = tdp->arg;
> > > > > + dtv_t *dtv = *(dtv_t **)((char *)__thread_pointer + DTV_OFFSET);
> > > > > + if (__builtin_expect (td->gen_count <= dtv[0].counter
> > > > > + && (dtv[td->tlsinfo.ti_module].pointer.val
> > > > > + != TLS_DTV_UNALLOCATED),
> > > > > + 1))
> > > > > + return dtv[td->tlsinfo.ti_module].pointer.val + td->tlsinfo.ti_offset
> > > > > + - __thread_pointer;
> > > > > +
> > > > > + return __tls_get_addr_internal (&td->tlsinfo) - __thread_pointer;
> > > > > +}
> > > > > +*/
> > > > > + cfi_startproc
> > > > > + .align 16
> > > > > +_dl_tlsdesc_dynamic:
> > > > > + _CET_ENDBR
> > > > > + /* Preserve call-clobbered registers that we modify.
> > > > > + We need two scratch regs anyway. */
> > > > > + movq %rsi, -16(%rsp)
> > > > > + mov %fs:DTV_OFFSET, %RSI_LP
> > > > > + movq %rdi, -8(%rsp)
> > > > > + movq TLSDESC_ARG(%rax), %rdi
> > > > > + movq (%rsi), %rax
> > > > > + cmpq %rax, TLSDESC_GEN_COUNT(%rdi)
> > > > > + ja 2f
> > > > > + movq TLSDESC_MODID(%rdi), %rax
> > > > > + salq $4, %rax
> > > > > + movq (%rax,%rsi), %rax
> > > > > + cmpq $-1, %rax
> > > > > + je 2f
> > > > > + addq TLSDESC_MODOFF(%rdi), %rax
> > > > > +1:
> > > > > + movq -16(%rsp), %rsi
> > > > > + sub %fs:0, %RAX_LP
> > > > > + movq -8(%rsp), %rdi
> > > > > + ret
> > > > > +2:
> > > > > +#if DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > + movq %rbx, -24(%rsp)
> > > > > + mov %RSP_LP, %RBX_LP
> > > > > + cfi_def_cfa_register(%rbx)
> > > > > + and $-STATE_SAVE_ALIGNMENT, %RSP_LP
> > > > > +#endif
> > > > > +#ifdef REGISTER_SAVE_AREA
> > > > > +# if DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > + /* STATE_SAVE_OFFSET has space for 8 integer registers. But we
> > > > > + need space for RCX, RDX, RSI, RDI, R8, R9, R10 and R11, plus
> > > > > + RBX above. */
> > > > > + sub $(REGISTER_SAVE_AREA + STATE_SAVE_ALIGNMENT), %RSP_LP
> > > > > +# else
> > > > > + sub $REGISTER_SAVE_AREA, %RSP_LP
> > > > > + cfi_adjust_cfa_offset(REGISTER_SAVE_AREA)
> > > > > +# endif
> > > > > +#else
> > > > > + /* Allocate stack space of the required size to save the state. */
> > > > > + sub _rtld_local_ro+RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET+XSAVE_STATE_SIZE_OFFSET(%rip), %RSP_LP
> > > > > +#endif
> > > > > + /* Besides rdi and rsi, saved above, save rcx, rdx, r8, r9,
> > > > > + r10 and r11. */
> > > > > + movq %rcx, REGISTER_SAVE_RCX(%rsp)
> > > > > + movq %rdx, REGISTER_SAVE_RDX(%rsp)
> > > > > + movq %r8, REGISTER_SAVE_R8(%rsp)
> > > > > + movq %r9, REGISTER_SAVE_R9(%rsp)
> > > > > + movq %r10, REGISTER_SAVE_R10(%rsp)
> > > > > + movq %r11, REGISTER_SAVE_R11(%rsp)
> > > > > +#ifdef USE_FXSAVE
> > > > > + fxsave STATE_SAVE_OFFSET(%rsp)
> > > > > +#else
> > > > > + movl $TLSDESC_CALL_STATE_SAVE_MASK, %eax
> > > > > + xorl %edx, %edx
> > > > > + /* Clear the XSAVE Header. */
> > > > > +# ifdef USE_XSAVE
> > > > > + movq %rdx, (STATE_SAVE_OFFSET + 512)(%rsp)
> > > > > + movq %rdx, (STATE_SAVE_OFFSET + 512 + 8)(%rsp)
> > > > > +# endif
> > > > > + movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 2)(%rsp)
> > > > > + movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 3)(%rsp)
> > > > > + movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 4)(%rsp)
> > > > > + movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 5)(%rsp)
> > > > > + movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 6)(%rsp)
> > > > > + movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 7)(%rsp)
> > > > > +# ifdef USE_XSAVE
> > > > > + xsave STATE_SAVE_OFFSET(%rsp)
> > > > > +# else
> > > > > + xsavec STATE_SAVE_OFFSET(%rsp)
> > > > > +# endif
> > > > > +#endif
> > > > > + /* %rdi already points to the tlsinfo data structure. */
> > > > > + call HIDDEN_JUMPTARGET (__tls_get_addr)
> > > > > + # Get register content back.
> > > > > +#ifdef USE_FXSAVE
> > > > > + fxrstor STATE_SAVE_OFFSET(%rsp)
> > > > > +#else
> > > > > + /* Save and retore __tls_get_addr return value stored in RAX. */
> > > > > + mov %RAX_LP, %RCX_LP
> > > > > + movl $TLSDESC_CALL_STATE_SAVE_MASK, %eax
> > > > > + xorl %edx, %edx
> > > > > + xrstor STATE_SAVE_OFFSET(%rsp)
> > > > > + mov %RCX_LP, %RAX_LP
> > > > > +#endif
> > > > > + movq REGISTER_SAVE_R11(%rsp), %r11
> > > > > + movq REGISTER_SAVE_R10(%rsp), %r10
> > > > > + movq REGISTER_SAVE_R9(%rsp), %r9
> > > > > + movq REGISTER_SAVE_R8(%rsp), %r8
> > > > > + movq REGISTER_SAVE_RDX(%rsp), %rdx
> > > > > + movq REGISTER_SAVE_RCX(%rsp), %rcx
> > > > > +#if DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > + mov %RBX_LP, %RSP_LP
> > > > > + cfi_def_cfa_register(%rsp)
> > > > > + movq -24(%rsp), %rbx
> > > > > + cfi_restore(%rbx)
> > > > > +#else
> > > > > + add $REGISTER_SAVE_AREA, %RSP_LP
> > > > > + cfi_adjust_cfa_offset(-REGISTER_SAVE_AREA)
> > > > > +#endif
> > > > > + jmp 1b
> > > > > + cfi_endproc
> > > > > + .size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic
> > > > > +
> > > > > +#undef STATE_SAVE_ALIGNMENT
> > > > > diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S
> > > > > index f748af2ece..ea69f5223a 100644
> > > > > --- a/sysdeps/x86_64/dl-tlsdesc.S
> > > > > +++ b/sysdeps/x86_64/dl-tlsdesc.S
> > > > > @@ -18,7 +18,19 @@
> > > > >
> > > > > #include <sysdep.h>
> > > > > #include <tls.h>
> > > > > +#include <cpu-features-offsets.h>
> > > > > +#include <features-offsets.h>
> > > > > #include "tlsdesc.h"
> > > > > +#include "dl-trampoline-save.h"
> > > > > +
> > > > > +/* Area on stack to save and restore registers used for parameter
> > > > > + passing when calling _dl_tlsdesc_dynamic. */
> > > > > +#define REGISTER_SAVE_RCX 0
> > > > > +#define REGISTER_SAVE_RDX (REGISTER_SAVE_RCX + 8)
> > > > > +#define REGISTER_SAVE_R8 (REGISTER_SAVE_RDX + 8)
> > > > > +#define REGISTER_SAVE_R9 (REGISTER_SAVE_R8 + 8)
> > > > > +#define REGISTER_SAVE_R10 (REGISTER_SAVE_R9 + 8)
> > > > > +#define REGISTER_SAVE_R11 (REGISTER_SAVE_R10 + 8)
> > > > >
> > > > > .text
> > > > >
> > > > > @@ -67,80 +79,24 @@ _dl_tlsdesc_undefweak:
> > > > > .size _dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak
> > > > >
> > > > > #ifdef SHARED
> > > > > - .hidden _dl_tlsdesc_dynamic
> > > > > - .global _dl_tlsdesc_dynamic
> > > > > - .type _dl_tlsdesc_dynamic,@function
> > > > > -
> > > > > - /* %rax points to the TLS descriptor, such that 0(%rax) points to
> > > > > - _dl_tlsdesc_dynamic itself, and 8(%rax) points to a struct
> > > > > - tlsdesc_dynamic_arg object. It must return in %rax the offset
> > > > > - between the thread pointer and the object denoted by the
> > > > > - argument, without clobbering any registers.
> > > > > -
> > > > > - The assembly code that follows is a rendition of the following
> > > > > - C code, hand-optimized a little bit.
> > > > > -
> > > > > -ptrdiff_t
> > > > > -_dl_tlsdesc_dynamic (register struct tlsdesc *tdp asm ("%rax"))
> > > > > -{
> > > > > - struct tlsdesc_dynamic_arg *td = tdp->arg;
> > > > > - dtv_t *dtv = *(dtv_t **)((char *)__thread_pointer + DTV_OFFSET);
> > > > > - if (__builtin_expect (td->gen_count <= dtv[0].counter
> > > > > - && (dtv[td->tlsinfo.ti_module].pointer.val
> > > > > - != TLS_DTV_UNALLOCATED),
> > > > > - 1))
> > > > > - return dtv[td->tlsinfo.ti_module].pointer.val + td->tlsinfo.ti_offset
> > > > > - - __thread_pointer;
> > > > > -
> > > > > - return __tls_get_addr_internal (&td->tlsinfo) - __thread_pointer;
> > > > > -}
> > > > > -*/
> > > > > - cfi_startproc
> > > > > - .align 16
> > > > > -_dl_tlsdesc_dynamic:
> > > > > - _CET_ENDBR
> > > > > - /* Preserve call-clobbered registers that we modify.
> > > > > - We need two scratch regs anyway. */
> > > > > - movq %rsi, -16(%rsp)
> > > > > - mov %fs:DTV_OFFSET, %RSI_LP
> > > > > - movq %rdi, -8(%rsp)
> > > > > - movq TLSDESC_ARG(%rax), %rdi
> > > > > - movq (%rsi), %rax
> > > > > - cmpq %rax, TLSDESC_GEN_COUNT(%rdi)
> > > > > - ja .Lslow
> > > > > - movq TLSDESC_MODID(%rdi), %rax
> > > > > - salq $4, %rax
> > > > > - movq (%rax,%rsi), %rax
> > > > > - cmpq $-1, %rax
> > > > > - je .Lslow
> > > > > - addq TLSDESC_MODOFF(%rdi), %rax
> > > > > -.Lret:
> > > > > - movq -16(%rsp), %rsi
> > > > > - sub %fs:0, %RAX_LP
> > > > > - movq -8(%rsp), %rdi
> > > > > - ret
> > > > > -.Lslow:
> > > > > - /* Besides rdi and rsi, saved above, save rdx, rcx, r8, r9,
> > > > > - r10 and r11. Also, align the stack, that's off by 8 bytes. */
> > > > > - subq $72, %rsp
> > > > > - cfi_adjust_cfa_offset (72)
> > > > > - movq %rdx, 8(%rsp)
> > > > > - movq %rcx, 16(%rsp)
> > > > > - movq %r8, 24(%rsp)
> > > > > - movq %r9, 32(%rsp)
> > > > > - movq %r10, 40(%rsp)
> > > > > - movq %r11, 48(%rsp)
> > > > > - /* %rdi already points to the tlsinfo data structure. */
> > > > > - call HIDDEN_JUMPTARGET (__tls_get_addr)
> > > > > - movq 8(%rsp), %rdx
> > > > > - movq 16(%rsp), %rcx
> > > > > - movq 24(%rsp), %r8
> > > > > - movq 32(%rsp), %r9
> > > > > - movq 40(%rsp), %r10
> > > > > - movq 48(%rsp), %r11
> > > > > - addq $72, %rsp
> > > > > - cfi_adjust_cfa_offset (-72)
> > > > > - jmp .Lret
> > > > > - cfi_endproc
> > > > > - .size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic
> > > > > +# define USE_FXSAVE
> > > > > +# define STATE_SAVE_ALIGNMENT 16
> > > > > +# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_fxsave
> > > > > +# include "dl-tlsdesc-dynamic.h"
> > > > > +# undef _dl_tlsdesc_dynamic
> > > > > +# undef USE_FXSAVE
> > > > > +
> > > > > +# define USE_XSAVE
> > > > > +# define STATE_SAVE_ALIGNMENT 64
> > > > > +# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_xsave
> > > > > +# include "dl-tlsdesc-dynamic.h"
> > > > > +# undef _dl_tlsdesc_dynamic
> > > > > +# undef USE_XSAVE
> > > > > +
> > > > > +# define USE_XSAVEC
> > > > > +# define STATE_SAVE_ALIGNMENT 64
> > > > > +# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_xsavec
> > > > > +# include "dl-tlsdesc-dynamic.h"
> > > > > +# undef _dl_tlsdesc_dynamic
> > > > > +# undef USE_XSAVEC
> > > > > #endif /* SHARED */
> > > > > diff --git a/sysdeps/x86_64/dl-trampoline-save.h b/sysdeps/x86_64/dl-trampoline-save.h
> > > > > new file mode 100644
> > > > > index 0000000000..84eac4a8ac
> > > > > --- /dev/null
> > > > > +++ b/sysdeps/x86_64/dl-trampoline-save.h
> > > > > @@ -0,0 +1,34 @@
> > > > > +/* x86-64 PLT trampoline register save macros.
> > > > > + Copyright (C) 2024 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 DL_STACK_ALIGNMENT
> > > > > +/* Due to GCC bug:
> > > > > +
> > > > > + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
> > > > > +
> > > > > + __tls_get_addr may be called with 8-byte stack alignment. Although
> > > > > + this bug has been fixed in GCC 4.9.4, 5.3 and 6, we can't assume
> > > > > + that stack will be always aligned at 16 bytes. */
> > > > > +# define DL_STACK_ALIGNMENT 8
> > > > > +#endif
> > > > > +
> > > > > +/* True if _dl_runtime_resolve should align stack for STATE_SAVE or align
> > > > > + stack to 16 bytes before calling _dl_fixup. */
> > > > > +#define DL_RUNTIME_RESOLVE_REALIGN_STACK \
> > > > > + (STATE_SAVE_ALIGNMENT > DL_STACK_ALIGNMENT \
> > > > > + || 16 > DL_STACK_ALIGNMENT)
> > > > > diff --git a/sysdeps/x86_64/dl-trampoline-state.h b/sysdeps/x86_64/dl-trampoline-state.h
> > > > > new file mode 100644
> > > > > index 0000000000..575f120797
> > > > > --- /dev/null
> > > > > +++ b/sysdeps/x86_64/dl-trampoline-state.h
> > > > > @@ -0,0 +1,51 @@
> > > > > +/* x86-64 PLT dl-trampoline state macros.
> > > > > + Copyright (C) 2024 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/>. */
> > > > > +
> > > > > +#if (STATE_SAVE_ALIGNMENT % 16) != 0
> > > > > +# error STATE_SAVE_ALIGNMENT must be multiple of 16
> > > > > +#endif
> > > > > +
> > > > > +#if (STATE_SAVE_OFFSET % STATE_SAVE_ALIGNMENT) != 0
> > > > > +# error STATE_SAVE_OFFSET must be multiple of STATE_SAVE_ALIGNMENT
> > > > > +#endif
> > > > > +
> > > > > +#if DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > +/* Local stack area before jumping to function address: RBX. */
> > > > > +# define LOCAL_STORAGE_AREA 8
> > > > > +# define BASE rbx
> > > > > +# ifdef USE_FXSAVE
> > > > > +/* Use fxsave to save XMM registers. */
> > > > > +# define REGISTER_SAVE_AREA (512 + STATE_SAVE_OFFSET)
> > > > > +# if (REGISTER_SAVE_AREA % 16) != 0
> > > > > +# error REGISTER_SAVE_AREA must be multiple of 16
> > > > > +# endif
> > > > > +# endif
> > > > > +#else
> > > > > +# ifndef USE_FXSAVE
> > > > > +# error USE_FXSAVE must be defined
> > > > > +# endif
> > > > > +/* Use fxsave to save XMM registers. */
> > > > > +# define REGISTER_SAVE_AREA (512 + STATE_SAVE_OFFSET + 8)
> > > > > +/* Local stack area before jumping to function address: All saved
> > > > > + registers. */
> > > > > +# define LOCAL_STORAGE_AREA REGISTER_SAVE_AREA
> > > > > +# define BASE rsp
> > > > > +# if (REGISTER_SAVE_AREA % 16) != 8
> > > > > +# error REGISTER_SAVE_AREA must be odd multiple of 8
> > > > > +# endif
> > > > > +#endif
> > > > > diff --git a/sysdeps/x86_64/dl-trampoline.S b/sysdeps/x86_64/dl-trampoline.S
> > > > > index b2e7e0f69b..87c5137837 100644
> > > > > --- a/sysdeps/x86_64/dl-trampoline.S
> > > > > +++ b/sysdeps/x86_64/dl-trampoline.S
> > > > > @@ -22,25 +22,7 @@
> > > > > #include <features-offsets.h>
> > > > > #include <link-defines.h>
> > > > > #include <isa-level.h>
> > > > > -
> > > > > -#ifndef DL_STACK_ALIGNMENT
> > > > > -/* Due to GCC bug:
> > > > > -
> > > > > - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
> > > > > -
> > > > > - __tls_get_addr may be called with 8-byte stack alignment. Although
> > > > > - this bug has been fixed in GCC 4.9.4, 5.3 and 6, we can't assume
> > > > > - that stack will be always aligned at 16 bytes. We use unaligned
> > > > > - 16-byte move to load and store SSE registers, which has no penalty
> > > > > - on modern processors if stack is 16-byte aligned. */
> > > > > -# define DL_STACK_ALIGNMENT 8
> > > > > -#endif
> > > > > -
> > > > > -/* True if _dl_runtime_resolve should align stack for STATE_SAVE or align
> > > > > - stack to 16 bytes before calling _dl_fixup. */
> > > > > -#define DL_RUNTIME_RESOLVE_REALIGN_STACK \
> > > > > - (STATE_SAVE_ALIGNMENT > DL_STACK_ALIGNMENT \
> > > > > - || 16 > DL_STACK_ALIGNMENT)
> > > > > +#include "dl-trampoline-save.h"
> > > > >
> > > > > /* Area on stack to save and restore registers used for parameter
> > > > > passing when calling _dl_fixup. */
> > > > > diff --git a/sysdeps/x86_64/dl-trampoline.h b/sysdeps/x86_64/dl-trampoline.h
> > > > > index f55c6ea040..d9ccfb40d4 100644
> > > > > --- a/sysdeps/x86_64/dl-trampoline.h
> > > > > +++ b/sysdeps/x86_64/dl-trampoline.h
> > > > > @@ -27,39 +27,7 @@
> > > > > # undef LOCAL_STORAGE_AREA
> > > > > # undef BASE
> > > > >
> > > > > -# if (STATE_SAVE_ALIGNMENT % 16) != 0
> > > > > -# error STATE_SAVE_ALIGNMENT must be multiple of 16
> > > > > -# endif
> > > > > -
> > > > > -# if (STATE_SAVE_OFFSET % STATE_SAVE_ALIGNMENT) != 0
> > > > > -# error STATE_SAVE_OFFSET must be multiple of STATE_SAVE_ALIGNMENT
> > > > > -# endif
> > > > > -
> > > > > -# if DL_RUNTIME_RESOLVE_REALIGN_STACK
> > > > > -/* Local stack area before jumping to function address: RBX. */
> > > > > -# define LOCAL_STORAGE_AREA 8
> > > > > -# define BASE rbx
> > > > > -# ifdef USE_FXSAVE
> > > > > -/* Use fxsave to save XMM registers. */
> > > > > -# define REGISTER_SAVE_AREA (512 + STATE_SAVE_OFFSET)
> > > > > -# if (REGISTER_SAVE_AREA % 16) != 0
> > > > > -# error REGISTER_SAVE_AREA must be multiple of 16
> > > > > -# endif
> > > > > -# endif
> > > > > -# else
> > > > > -# ifndef USE_FXSAVE
> > > > > -# error USE_FXSAVE must be defined
> > > > > -# endif
> > > > > -/* Use fxsave to save XMM registers. */
> > > > > -# define REGISTER_SAVE_AREA (512 + STATE_SAVE_OFFSET + 8)
> > > > > -/* Local stack area before jumping to function address: All saved
> > > > > - registers. */
> > > > > -# define LOCAL_STORAGE_AREA REGISTER_SAVE_AREA
> > > > > -# define BASE rsp
> > > > > -# if (REGISTER_SAVE_AREA % 16) != 8
> > > > > -# error REGISTER_SAVE_AREA must be odd multiple of 8
> > > > > -# endif
> > > > > -# endif
> > > > > +# include "dl-trampoline-state.h"
> > > > >
> > > > > .globl _dl_runtime_resolve
> > > > > .hidden _dl_runtime_resolve
> > > > > --
> > > > > 2.43.2
> > > > >
> > > >
> > > > This still LGTM.
> > > > Feel free to add my reviewed-by tag to future posts of the patch.
> > > > Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
> > >
> > > Please wait for community consensus before pushing
> >
> > It was agreed that I should send out the v10 patch with xfail on
> > the new test. Someone just needs to double check that my
> > v10 patch does it.
> Okay, give it 24 hour. If you no further concerns are brought up
> think its okay to push.
OK to backport it to release branches?
--
H.J.
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