mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-19 03:20:05 +00:00
55 lines
1.6 KiB
C
55 lines
1.6 KiB
C
/* brk system call for Linux/i386.
|
|
Copyright (C) 1995, 1996 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 Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
|
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
|
|
Cambridge, MA 02139, USA. */
|
|
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
#include <sysdep.h>
|
|
|
|
void *__curbrk;
|
|
|
|
/* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
|
|
to work around different old braindamage in the old Linux ELF dynamic
|
|
linker. */
|
|
weak_alias (__curbrk, ___brk_addr)
|
|
|
|
int
|
|
__brk (void *addr)
|
|
{
|
|
void *newbrk, *scratch;
|
|
|
|
asm ("movl %%ebx, %1\n" /* Save %ebx in scratch register. */
|
|
"movl %3, %%ebx\n" /* Put ADDR in %ebx to be syscall arg. */
|
|
"int $0x80 # %2\n" /* Perform the system call. */
|
|
"movl %1, %%ebx\n" /* Restore %ebx from scratch register. */
|
|
: "=a" (newbrk), "=r" (scratch)
|
|
: "0" (SYS_ify (brk)), "g" (addr));
|
|
|
|
__curbrk = newbrk;
|
|
|
|
if (newbrk < addr)
|
|
{
|
|
errno = ENOMEM;
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
weak_alias (__brk, brk)
|
|
|