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glibc/sysdeps/unix/sysv/linux/i386/mmap.S
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/* Copyright (C) 1995-2012 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> | |
#include <kernel-features.h> | |
#define EINVAL 22 | |
.text | |
ENTRY (__mmap) | |
/* I don't think it is worthwhile trying to use mmap2 whenever it | |
is available. Only use it when we are sure the syscall exists. */ | |
#ifdef __ASSUME_MMAP2_SYSCALL | |
/* Save registers. */ | |
pushl %ebp | |
cfi_adjust_cfa_offset (4) | |
pushl %ebx | |
cfi_adjust_cfa_offset (4) | |
pushl %esi | |
cfi_adjust_cfa_offset (4) | |
pushl %edi | |
cfi_adjust_cfa_offset (4) | |
movl 20(%esp), %ebx | |
cfi_rel_offset (ebx, 8) | |
movl 24(%esp), %ecx | |
movl 28(%esp), %edx | |
movl 32(%esp), %esi | |
cfi_rel_offset (esi, 4) | |
movl 36(%esp), %edi | |
cfi_rel_offset (edi, 0) | |
movl 40(%esp), %ebp | |
cfi_rel_offset (ebp, 12) | |
testl $0xfff, %ebp | |
movl $-EINVAL, %eax | |
jne L(skip) | |
shrl $12, %ebp /* mmap2 takes the offset in pages. */ | |
movl $SYS_ify(mmap2), %eax /* System call number in %eax. */ | |
/* Do the system call trap. */ | |
ENTER_KERNEL | |
L(skip): | |
/* Restore registers. */ | |
popl %edi | |
cfi_adjust_cfa_offset (-4) | |
cfi_restore (edi) | |
popl %esi | |
cfi_adjust_cfa_offset (-4) | |
cfi_restore (esi) | |
popl %ebx | |
cfi_adjust_cfa_offset (-4) | |
cfi_restore (ebx) | |
popl %ebp | |
cfi_adjust_cfa_offset (-4) | |
cfi_restore (ebp) | |
#else | |
/* Save registers. */ | |
movl %ebx, %edx | |
cfi_register (ebx, edx) | |
movl $SYS_ify(mmap), %eax /* System call number in %eax. */ | |
lea 4(%esp), %ebx /* Address of args is 1st arg. */ | |
/* Do the system call trap. */ | |
int $0x80 | |
/* Restore registers. */ | |
movl %edx, %ebx | |
cfi_restore (ebx) | |
#endif | |
/* If 0 > %eax > -4096 there was an error. */ | |
cmpl $-4096, %eax | |
ja SYSCALL_ERROR_LABEL | |
/* Successful; return the syscall's value. */ | |
ret | |
PSEUDO_END (__mmap) | |
weak_alias (__mmap, mmap) |