glibc/sysdeps/unix/sysv/linux/i386/clone.S
Siddhesh Poyarekar 30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30

116 lines
3.0 KiB
ArmAsm

/* Copyright (C) 1996-2021 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
<https://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
.text
ENTRY (__clone)
/* Sanity check arguments. */
movl $-EINVAL,%eax
movl FUNC(%esp),%ecx /* no NULL function pointers */
testl %ecx,%ecx
jz SYSCALL_ERROR_LABEL
movl STACK(%esp),%ecx /* no NULL stack pointers */
testl %ecx,%ecx
jz SYSCALL_ERROR_LABEL
/* 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 */
call *%ebx
movl %eax, %ebx
movl $SYS_ify(exit), %eax
ENTER_KERNEL
PSEUDO_END (__clone)
libc_hidden_def (__clone)
weak_alias (__clone, clone)