glibc/sysdeps/unix/sysv/linux/powerpc/powerpc64/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

113 lines
3.0 KiB
ArmAsm

/* Wrapper around clone system call. PowerPC64 version.
Copyright (C) 1997-2017 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/>. */
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
/* This is the only really unusual system call in PPC linux, but not
because of any weirdness in the system call itself; because of
all the freaky stuff we have to do to make the call useful. */
/* int [r3] clone(int (*fn)(void *arg) [r3], void *child_stack [r4],
int flags [r5], void *arg [r6], void *parent_tid [r7],
void *tls [r8], void *child_tid [r9]); */
ENTRY (__clone)
CALL_MCOUNT 7
/* Check for child_stack == NULL || fn == NULL. */
cmpdi cr0,r4,0
cmpdi cr1,r3,0
cror cr0*4+eq,cr1*4+eq,cr0*4+eq
beq- cr0,L(badargs)
/* Save some regs in the "red zone". */
std r29,-24(r1)
std r30,-16(r1)
std r31,-8(r1)
cfi_offset(r29,-24)
cfi_offset(r30,-16)
cfi_offset(r31,-8)
/* Set up stack frame for child. */
clrrdi r4,r4,4
li r0,0
stdu r0,-FRAME_MIN_SIZE_PARM(r4)
/* Save fn, args, stack across syscall. */
mr r30,r3 /* Function in r30. */
mr r29,r5 /* Flags in r29. */
mr r31,r6 /* Argument in r31. */
/* 'flags' argument is first parameter to clone syscall.
Second is the stack pointer, already in r4. */
mr r3,r5
/* Move the parent_tid, child_tid and tls arguments. */
mr r5,r7
mr r6,r8
mr r7,r9
/* End FDE now, because in the child the unwind info will be
wrong. */
cfi_endproc
/* Do the call. */
DO_CALL(SYS_ify(clone))
/* Check for child process. */
cmpdi cr1,r3,0
crandc cr1*4+eq,cr1*4+eq,cr0*4+so
bne- cr1,L(parent) /* The '-' is to minimise the race. */
std r2,FRAME_TOC_SAVE(r1)
/* Call procedure. */
PPC64_LOAD_FUNCPTR r30
mr r3,r31
bctrl
ld r2,FRAME_TOC_SAVE(r1)
DO_CALL(SYS_ify(exit))
/* We won't ever get here but provide a nop so that the linker
will insert a toc adjusting stub if necessary. */
nop
L(badargs):
cfi_startproc
li r3,EINVAL
TAIL_CALL_SYSCALL_ERROR
L(parent):
/* Parent. Restore registers & return. */
cfi_offset(r29,-24)
cfi_offset(r30,-16)
cfi_offset(r31,-8)
ld r29,-24(r1)
ld r30,-16(r1)
ld r31,-8(r1)
cfi_restore(r29)
cfi_restore(r30)
cfi_restore(r31)
PSEUDO_RET
END (__clone)
libc_hidden_def (__clone)
weak_alias (__clone, clone)