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glibc  2.9
brk.c
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00001 /* brk system call for Linux/MIPS.
00002    Copyright (C) 2000, 2005, 2006 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <errno.h>
00021 #include <unistd.h>
00022 #include <sysdep.h>
00023 
00024 void *__curbrk = 0;
00025 
00026 /* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
00027    to work around different old braindamage in the old Linux/x86 ELF
00028    dynamic linker.  Sigh.  */
00029 weak_alias (__curbrk, ___brk_addr)
00030 
00031 int
00032 __brk (void *addr)
00033 {
00034   void *newbrk;
00035 
00036   {
00037     register long int res __asm__ ("$2");
00038 
00039     asm ("move\t$4,%2\n\t"
00040         "li\t%0,%1\n\t"
00041         "syscall"           /* Perform the system call.  */
00042         : "=r" (res)
00043         : "I" (SYS_ify (brk)), "r" (addr)
00044         : "$4", "$7", __SYSCALL_CLOBBERS);
00045     newbrk = (void *) res;
00046   }
00047   __curbrk = newbrk;
00048 
00049   if (newbrk < addr)
00050     {
00051       __set_errno (ENOMEM);
00052       return -1;
00053     }
00054 
00055   return 0;
00056 }
00057 weak_alias (__brk, brk)