mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-21 04:31:04 +08:00
151 lines
3.5 KiB
ArmAsm
151 lines
3.5 KiB
ArmAsm
/* Copyright (C) 1996-2015 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Richard Henderson (rth@tamu.edu)
|
|
|
|
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 <asm-syntax.h>
|
|
|
|
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
|
|
pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
|
|
|
|
#define PARMS 4 /* no space for saved regs */
|
|
#define FUNC PARMS
|
|
#define STACK FUNC+4
|
|
#define FLAGS STACK+4
|
|
#define ARG FLAGS+4
|
|
#define PTID ARG+4
|
|
#define TLS PTID+4
|
|
#define CTID TLS+4
|
|
|
|
#define __NR_clone 120
|
|
#define SYS_clone 120
|
|
|
|
#define CLONE_VM 0x00000100
|
|
#define CLONE_THREAD 0x00010000
|
|
|
|
.text
|
|
ENTRY (__clone)
|
|
/* Sanity check arguments. */
|
|
movl $-EINVAL,%eax
|
|
movl FUNC(%esp),%ecx /* no NULL function pointers */
|
|
#ifdef PIC
|
|
jecxz SYSCALL_ERROR_LABEL
|
|
#else
|
|
testl %ecx,%ecx
|
|
jz SYSCALL_ERROR_LABEL
|
|
#endif
|
|
movl STACK(%esp),%ecx /* no NULL stack pointers */
|
|
#ifdef PIC
|
|
jecxz SYSCALL_ERROR_LABEL
|
|
#else
|
|
testl %ecx,%ecx
|
|
jz SYSCALL_ERROR_LABEL
|
|
#endif
|
|
|
|
/* Insert the argument onto the new stack. Make sure the new
|
|
thread is started with an alignment of (mod 16). */
|
|
andl $0xfffffff0, %ecx
|
|
subl $28,%ecx
|
|
movl ARG(%esp),%eax /* no negative argument counts */
|
|
movl %eax,12(%ecx)
|
|
|
|
/* Save the function pointer as the zeroth argument.
|
|
It will be popped off in the child in the ebx frobbing below. */
|
|
movl FUNC(%esp),%eax
|
|
movl %eax,8(%ecx)
|
|
/* Don't leak any information. */
|
|
movl $0,4(%ecx)
|
|
|
|
/* Do the system call */
|
|
pushl %ebx
|
|
cfi_adjust_cfa_offset (4)
|
|
pushl %esi
|
|
cfi_adjust_cfa_offset (4)
|
|
pushl %edi
|
|
cfi_adjust_cfa_offset (4)
|
|
|
|
movl TLS+12(%esp),%esi
|
|
cfi_rel_offset (esi, 4)
|
|
movl PTID+12(%esp),%edx
|
|
movl FLAGS+12(%esp),%ebx
|
|
cfi_rel_offset (ebx, 8)
|
|
movl CTID+12(%esp),%edi
|
|
cfi_rel_offset (edi, 0)
|
|
movl $SYS_ify(clone),%eax
|
|
|
|
/* Remember the flag value. */
|
|
movl %ebx, (%ecx)
|
|
|
|
/* End FDE now, because in the child the unwind info will be
|
|
wrong. */
|
|
cfi_endproc
|
|
|
|
int $0x80
|
|
popl %edi
|
|
popl %esi
|
|
popl %ebx
|
|
|
|
test %eax,%eax
|
|
jl SYSCALL_ERROR_LABEL
|
|
jz L(thread_start)
|
|
|
|
ret
|
|
|
|
L(thread_start):
|
|
cfi_startproc;
|
|
/* Clearing frame pointer is insufficient, use CFI. */
|
|
cfi_undefined (eip);
|
|
/* Note: %esi is zero. */
|
|
movl %esi,%ebp /* terminate the stack frame */
|
|
testl $CLONE_THREAD, %edi
|
|
je L(newpid)
|
|
L(haspid):
|
|
call *%ebx
|
|
#ifdef PIC
|
|
call L(here)
|
|
L(here):
|
|
popl %ebx
|
|
addl $_GLOBAL_OFFSET_TABLE_+[.-L(here)], %ebx
|
|
#endif
|
|
movl %eax, %ebx
|
|
movl $SYS_ify(exit), %eax
|
|
ENTER_KERNEL
|
|
|
|
.subsection 2
|
|
L(newpid):
|
|
testl $CLONE_VM, %edi
|
|
movl $-1, %eax
|
|
jne L(nomoregetpid)
|
|
movl $SYS_ify(getpid), %eax
|
|
ENTER_KERNEL
|
|
L(nomoregetpid):
|
|
movl %eax, %gs:PID
|
|
movl %eax, %gs:TID
|
|
jmp L(haspid)
|
|
.previous
|
|
cfi_endproc;
|
|
|
|
cfi_startproc
|
|
PSEUDO_END (__clone)
|
|
|
|
weak_alias (__clone, clone)
|