From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org, Christian Brauner <brauner@kernel.org>
Subject: [PATCH v2 7/9] arm: Add the clone3 wrapper
Date: Fri, 30 Sep 2022 16:26:11 -0300 [thread overview]
Message-ID: <20220930192613.3491147-8-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <20220930192613.3491147-1-adhemerval.zanella@linaro.org>
It follows the internal signature:
extern int clone3 (struct clone_args *__cl_args, size_t __size,
int (*__func) (void *__arg), void *__arg);
And x86_64 semantics to return EINVAL if either cl_args or func
is NULL. The stack is 16-byte aligned prior executing func.
Checked on arm-linux-gnueabihf.
---
sysdeps/unix/sysv/linux/arm/clone3.S | 80 ++++++++++++++++++++++++++++
sysdeps/unix/sysv/linux/arm/sysdep.h | 1 +
2 files changed, 81 insertions(+)
create mode 100644 sysdeps/unix/sysv/linux/arm/clone3.S
diff --git a/sysdeps/unix/sysv/linux/arm/clone3.S b/sysdeps/unix/sysv/linux/arm/clone3.S
new file mode 100644
index 0000000000..f6b274cf51
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/clone3.S
@@ -0,0 +1,80 @@
+/* The clone3 syscall wrapper. Linux/arm 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 <sysdep.h>
+#define _ERRNO_H 1
+#include <bits/errno.h>
+
+/* The userland implementation is:
+ int clone3 (struct clone_args *cl_args, size_t size,
+ int (*func)(void *arg), void *arg);
+
+ the kernel entry is:
+ int clone3 (struct clone_args *cl_args, size_t size);
+
+ The parameters are passed in registers from userland:
+ r0: cl_args
+ r1: size
+ r2: func
+ r3: arg */
+
+ .text
+ENTRY(__clone3)
+ /* Sanity check args. */
+ cmp r0, #0
+ ite ne
+ cmpne r1, #0
+ moveq r0, #-EINVAL
+ beq PLTJMP(syscall_error)
+
+ /* Do the syscall, the kernel expects:
+ r7: system call number:
+ r0: cl_args
+ r1: size */
+ ldr r7, =SYS_ify(clone3)
+ swi 0x0
+ cfi_endproc
+
+ cmp r0, #0
+ beq 1f
+
+ blt PLTJMP(C_SYMBOL_NAME(__syscall_error))
+ RETINSTR(, lr)
+
+ cfi_startproc
+PSEUDO_END (__clone3)
+
+1:
+ .fnstart
+ .cantunwind
+ /* Align sp. */
+ and sp, sp, #-8
+
+ mov r0, r3
+ mov ip, r2
+ BLX (ip)
+
+ /* And we are done, passing the return value through r0. */
+ ldr r7, =SYS_ify(exit)
+ swi 0x0
+
+ .fnend
+
+libc_hidden_def (__clone3)
+weak_alias (__clone3, clone3)
diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h
index 1f270b961e..fcc86189d6 100644
--- a/sysdeps/unix/sysv/linux/arm/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arm/sysdep.h
@@ -362,6 +362,7 @@ __local_syscall_error: \
#define HAVE_CLOCK_GETTIME_VSYSCALL "__vdso_clock_gettime"
#define HAVE_CLOCK_GETTIME64_VSYSCALL "__vdso_clock_gettime64"
#define HAVE_GETTIMEOFDAY_VSYSCALL "__vdso_gettimeofday"
+#define HAVE_CLONE3_WRAPPER 1
#define LOAD_ARGS_0()
#define ASM_ARGS_0
--
2.34.1
next prev parent reply other threads:[~2022-09-30 19:26 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-30 19:26 [PATCH v2 0/9] Optimize posix_spawn signal setup with clone3 Adhemerval Zanella
2022-09-30 19:26 ` [PATCH v2 1/9] linux: Do not reset signal handler in posix_spawn if it is already SIG_DFL Adhemerval Zanella
2023-01-11 21:06 ` Carlos O'Donell
2022-09-30 19:26 ` [PATCH v2 2/9] linux: Add clone3 CLONE_CLEAR_SIGHAND optimization to posix_spawn Adhemerval Zanella
2023-01-11 21:06 ` Carlos O'Donell
2022-09-30 19:26 ` [PATCH v2 3/9] powerpc64le: Add the clone3 wrapper Adhemerval Zanella
2022-09-30 19:26 ` [PATCH v2 4/9] aarch64: " Adhemerval Zanella
2022-11-02 12:12 ` Szabolcs Nagy
2022-11-03 13:15 ` Adhemerval Zanella Netto
2022-11-03 14:01 ` Szabolcs Nagy
2022-11-03 16:22 ` Adhemerval Zanella Netto
2022-11-03 16:31 ` Szabolcs Nagy
2022-11-03 16:39 ` Adhemerval Zanella Netto
2022-11-03 16:52 ` Szabolcs Nagy
2022-11-03 16:55 ` Adhemerval Zanella Netto
2022-11-03 20:55 ` H.J. Lu
2022-11-03 21:28 ` Adhemerval Zanella Netto
2022-11-03 21:22 ` Adhemerval Zanella Netto
2022-11-03 21:58 ` H.J. Lu
2022-11-04 12:32 ` Adhemerval Zanella Netto
2022-09-30 19:26 ` [PATCH v2 5/9] s390x: " Adhemerval Zanella
2022-09-30 19:26 ` [PATCH v2 6/9] riscv: " Adhemerval Zanella
2022-09-30 19:26 ` Adhemerval Zanella [this message]
2022-09-30 19:26 ` [PATCH v2 8/9] mips: " Adhemerval Zanella
2022-09-30 19:26 ` [PATCH v2 9/9] Linux: optimize clone3 internal usage Adhemerval Zanella
2023-01-11 21:12 ` Carlos O'Donell
2022-10-27 16:48 ` [PATCH v2 0/9] Optimize posix_spawn signal setup with clone3 Adhemerval Zanella Netto
2023-01-11 21:11 ` Carlos O'Donell
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