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/* Copyright (C) 1998, 2000, 2003 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., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
#include <kernel-features.h>
#define EINVAL 22
.text
ENTRY (__mmap)
# ifdef __ASSUME_MMAP2_SYSCALL
/* This code is actually a couple of cycles slower than the
sys_mmap version below, so it might seem like a loss. But the
code path inside the kernel is sufficiently much shorter to
make it a net gain to use mmap2 when it's known to be
available. */
/* shuffle args */
str r5, [sp, #-4]!
ldr r5, [sp, #8]
str r4, [sp, #-4]!
ldr r4, [sp, #8]
/* convert offset to pages */
movs ip, r5, lsl #20
bne .Linval
mov r5, r5, lsr #12
/* do the syscall */
swi SYS_ify (mmap2)
/* restore registers */
2:
ldr r4, [sp], #4
ldr r5, [sp], #4
cmn r0, $4096
RETINSTR(cc, lr)
b PLTJMP(syscall_error)
.Linval:
mov r0, #-EINVAL
b 2b
# else
/* Because we can only get five args through the syscall interface, and
mmap() takes six, we need to build a parameter block and pass its
address instead. The 386 port does a similar trick. */
/* This code previously moved sp into ip and stored the args using
stmdb ip!, {a1-a4}. It did not modify sp, so the stack never had
to be restored after the syscall completed. It saved an
instruction and meant no stack cleanup work was required.
This will not work in the case of a mmap call being interrupted
by a signal. If the signal handler uses any stack the arguments
to mmap will be trashed. The results of a restart of mmap are
then unpredictable. */
/* store args on the stack */
stmdb sp!, {a1-a4}
/* do the syscall */
mov a1, sp
swi SYS_ify (mmap)
/* pop args off the stack. */
add sp, sp, #16
cmn r0, $4096
RETINSTR(cc, lr)
b PLTJMP(syscall_error);
#endif
PSEUDO_END (__mmap)
weak_alias (__mmap, mmap)
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