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/* Wrapper around clone system call. PowerPC64 version.
Copyright (C) 1997-2013 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>
#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))
CALL_MCOUNT 7
/* GKM FIXME: add bounds checks, where sensible. */
DISCARD_BOUNDS (r4)
DISCARD_BOUNDS (r6)
/* 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 parm save area. */
#ifdef RESET_PID
std r29,48(r1)
#endif
std r30,56(r1)
std r31,64(r1)
#ifdef RESET_PID
cfi_offset(r29,48)
#endif
cfi_offset(r30,56)
cfi_offset(r31,64)
/* Set up stack frame for child. */
clrrdi r4,r4,4
li r0,0
stdu r0,-112(r4) /* min stack frame is 112 bytes per ABI */
/* Save fn, args, stack across syscall. */
mr r30,r3 /* Function in r30. */
#ifdef RESET_PID
mr r29,r5 /* Flags in r29. */
#endif
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. */
#ifdef RESET_PID
andis. r0,r29,CLONE_THREAD>>16
bne+ cr0,L(oldpid)
andi. r0,r29,CLONE_VM
li r3,-1
bne- cr0,L(nomoregetpid)
DO_CALL(SYS_ify(getpid))
L(nomoregetpid):
stw r3,TID(r13)
stw r3,PID(r13)
L(oldpid):
#endif
std r2,40(r1)
/* Call procedure. */
ld r0,0(r30)
ld r2,8(r30)
mtctr r0
mr r3,r31
bctrl
ld r2,40(r1)
/* Call _exit with result from procedure. */
#ifdef SHARED
b JUMPTARGET(__GI__exit)
#else
b JUMPTARGET(_exit)
/* We won't ever get here but provide a nop so that the linker
will insert a toc adjusting stub if necessary. */
nop
#endif
L(badargs):
cfi_startproc
li r3,EINVAL
TAIL_CALL_SYSCALL_ERROR
L(parent):
/* Parent. Restore registers & return. */
#ifdef RESET_PID
cfi_offset(r29,48)
#endif
cfi_offset(r30,56)
cfi_offset(r31,64)
#ifdef RESET_PID
ld r29,48(r1)
#endif
ld r30,56(r1)
ld r31,64(r1)
#ifdef RESET_PID
cfi_restore(r29)
#endif
cfi_restore(r30)
cfi_restore(r31)
PSEUDO_RET
END (BP_SYM (__clone))
weak_alias (BP_SYM (__clone), BP_SYM (clone))
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