mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 16:50:07 +00:00
150 lines
3.7 KiB
ArmAsm
150 lines
3.7 KiB
ArmAsm
/* Wrapper around clone system call.
|
|
Copyright (C) 1997,98,99,2000,02,04,2006 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, write to the Free
|
|
Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA
|
|
02110-1301 USA. */
|
|
|
|
#include <sysdep.h>
|
|
#define _ERRNO_H 1
|
|
#include <bits/errno.h>
|
|
#include <kernel-features.h>
|
|
#include <bp-sym.h>
|
|
#include <bp-asm.h>
|
|
|
|
#define CLONE_VM 0x00000100
|
|
#define CLONE_THREAD 0x00010000
|
|
|
|
|
|
/* 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 (BP_SYM (__clone))
|
|
/* GKM FIXME: add bounds checks, where sensible. */
|
|
DISCARD_BOUNDS (r4)
|
|
DISCARD_BOUNDS (r6)
|
|
|
|
/* Check for child_stack == NULL || fn == NULL. */
|
|
cmpwi cr0,r4,0
|
|
cmpwi cr1,r3,0
|
|
cror cr0*4+eq,cr1*4+eq,cr0*4+eq
|
|
beq- cr0,L(badargs)
|
|
|
|
/* Set up stack frame for parent. */
|
|
stwu r1,-32(r1)
|
|
cfi_adjust_cfa_offset (32)
|
|
#ifdef RESET_PID
|
|
stmw r28,16(r1)
|
|
#else
|
|
# ifndef __ASSUME_FIXED_CLONE_SYSCALL
|
|
stmw r29,16(r1)
|
|
# else
|
|
stmw r30,16(r1)
|
|
# endif
|
|
#endif
|
|
|
|
/* Set up stack frame for child. */
|
|
clrrwi r4,r4,4
|
|
li r0,0
|
|
stwu r0,-16(r4)
|
|
|
|
/* Save fn, args, stack across syscall. */
|
|
mr r30,r3 /* Function in r30. */
|
|
#ifndef __ASSUME_FIXED_CLONE_SYSCALL
|
|
mr r29,r4 /* Stack pointer in r29. */
|
|
#endif
|
|
#ifdef RESET_PID
|
|
mr r28,r5
|
|
#endif
|
|
mr r31,r6 /* Argument in r31. */
|
|
|
|
/* 'flags' argument is first parameter to clone syscall. (The other
|
|
argument 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. */
|
|
cmpwi cr1,r3,0
|
|
crandc cr1*4+eq,cr1*4+eq,cr0*4+so
|
|
bne- cr1,L(parent) /* The '-' is to minimise the race. */
|
|
|
|
#ifndef __ASSUME_FIXED_CLONE_SYSCALL
|
|
/* On at least mklinux DR3a5, clone() doesn't actually change
|
|
the stack pointer. I'm pretty sure this is a bug, because
|
|
it adds a race condition if a signal is sent to a thread
|
|
just after it is created (in the previous three instructions). */
|
|
mr r1,r29
|
|
#endif
|
|
|
|
#ifdef RESET_PID
|
|
andis. r0,r28,CLONE_THREAD>>16
|
|
bne+ r0,L(oldpid)
|
|
andi. r0,r28,CLONE_VM
|
|
li r3,-1
|
|
bne- r0,L(nomoregetpid)
|
|
DO_CALL(SYS_ify(getpid))
|
|
L(nomoregetpid):
|
|
stw r3,TID(r2)
|
|
stw r3,PID(r2)
|
|
L(oldpid):
|
|
#endif
|
|
|
|
/* Call procedure. */
|
|
mtctr r30
|
|
mr r3,r31
|
|
bctrl
|
|
/* Call _exit with result from procedure. */
|
|
b HIDDEN_JUMPTARGET(_exit)
|
|
|
|
L(parent):
|
|
/* Parent. Restore registers & return. */
|
|
#ifdef RESET_PID
|
|
lmw r28,16(r1)
|
|
#else
|
|
# ifndef __ASSUME_FIXED_CLONE_SYSCALL
|
|
lmw r29,16(r1)
|
|
# else
|
|
lmw r30,16(r1)
|
|
# endif
|
|
#endif
|
|
addi r1,r1,32
|
|
bnslr+
|
|
b __syscall_error@local
|
|
|
|
L(badargs):
|
|
li r3,EINVAL
|
|
b __syscall_error@local
|
|
|
|
cfi_startproc
|
|
END (BP_SYM (__clone))
|
|
|
|
weak_alias (BP_SYM (__clone), BP_SYM (clone))
|