glibc/sysdeps/unix/sysv/linux/sh/clone.S
Adhemerval Zanella 3f823e87cc Call exit directly in clone (BZ #21512)
On aarch64, alpha, arm, hppa, mips, nios2, powerpc, sh, sparc, tile,
and x86_64 the clone syscall jumps to _exit after the child execution
and the function ends the process execution by calling exit_group.
This behavior have a small issue where threads created with
CLONE_THREAD using clone syscall directly will eventually exit the
whole group altogether instead of just the thread created.  Also,
s390, microblaze, ia64, i386, and m68k differs by calling exit
syscall directly.

This patch changes all architectures to call the exit syscall
directly, as for s390, microblaze, ia64, i386, and m68k.  This do not
have change glibc internal behavior in any sort, since the only
usage of clone implementation in posix_spawn calls _exit directly
in the created child (fork uses a direct call to clone).

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
powerpc-linux-gnu, powerpc64le-linux-gnu, sparc64-linux-gnu,
and sparcv9-linux-gnu.

	[BZ #21512]
	* sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Call exit
	syscall instead of jump to _exit.
	(CLONE_VM_BIT): Remove unused define.
	(CLONE_VM): Likewise.
	(CLONE_THREAD_BIT): Likewise.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/alpha/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/arm/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/i386/clone.S (CLONE_VM): Likewise.
	* sysdeps/unix/sysv/linux/ia64/clone2.S (__clone2): Call exit
	syscall instead of jump to _exit.
	* sysdeps/unix/sysv/linux/hppa/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/mips/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/nios2/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S (__clone):
	Likewise.
	(CLONE_VM): Remove unused define.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (__clone):
	Likewise.
	(CLONE_VM): Remove unused define.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/sh/clone.S  (__clone): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/tile/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/x86_64/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/Makefile (tests): Add tst-clone3.
	* sysdeps/unix/sysv/linux/tst-clone3.c: New file.

Fix
2017-06-26 17:52:20 -03:00

87 lines
2.1 KiB
ArmAsm

/* Copyright (C) 1999-2017 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/>. */
/* clone() is even more special than fork() as it mucks with stacks
and invokes a function in the right context after its all over. */
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
#include <tcb-offsets.h>
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
pid_t *ptid, void *tls, pid_t *ctid); */
.text
ENTRY(__clone)
/* sanity check arguments. */
tst r4, r4
bt/s 0f
tst r5, r5
bf 1f
0:
bra .Lsyscall_error
mov #-EINVAL,r0
1:
/* insert the args onto the new stack */
mov.l r7, @-r5
/* save the function pointer as the 0th element */
mov.l r4, @-r5
/* do the system call */
mov r6, r4
mov.l @r15, r6
mov.l @(8,r15), r7
mov.l @(4,r15), r0
mov #+SYS_ify(clone), r3
trapa #0x15
mov r0, r1
mov #-12, r2
shad r2, r1
not r1, r1 // r1=0 means r0 = -1 to -4095
tst r1, r1 // i.e. error in linux
bf .Lclone_end
.Lsyscall_error:
SYSCALL_ERROR_HANDLER
.Lclone_end:
tst r0, r0
bt 2f
.Lpseudo_end:
rts
nop
2:
/* terminate the stack frame */
mov #0, r14
/* thread starts */
mov.l @r15, r1
jsr @r1
mov.l @(4,r15), r4
/* we are done, passing the return value through r0 */
mov #+SYS_ify(exit), r3
trapa #0x15
.align 2
.LG:
.long _GLOBAL_OFFSET_TABLE_
.L3:
.long PLTJMP(C_SYMBOL_NAME(_exit))
PSEUDO_END (__clone)
libc_hidden_def (__clone)
weak_alias (__clone, clone)