sysdeps/unix/sysv/linux/mips/brk.c

   1 /* brk system call for Linux/MIPS.
   2    Copyright (C) 2000, 2005, 2006 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library.  If not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <sysdep.h>
  22
  23 void *__curbrk = 0;
  24
  25 /* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
  26    to work around different old braindamage in the old Linux/x86 ELF
  27    dynamic linker.  Sigh.  */
  28 weak_alias (__curbrk, ___brk_addr)
  29
  30 int
  31 __brk (void *addr)
  32 {
  33   void *newbrk;
  34
  35   {
  36     register long int res __asm__ ("$2");
  37
  38     asm ("move\t$4,%2\n\t"
  39          "li\t%0,%1\n\t"
  40          "syscall"              /* Perform the system call.  */
  41          : "=r" (res)
  42          : "I" (SYS_ify (brk)), "r" (addr)
  43          : "$4", "$7", __SYSCALL_CLOBBERS);
  44     newbrk = (void *) res;
  45   }
  46   __curbrk = newbrk;
  47
  48   if (newbrk < addr)
  49     {
  50       __set_errno (ENOMEM);
  51       return -1;
  52     }
  53
  54   return 0;
  55 }
  56 weak_alias (__brk, brk)