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

   1 /* brk system call for Linux/MIPS.
   2    Copyright (C) 2000 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <sysdep.h>
  23
  24 void *__curbrk = 0;
  25
  26 /* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
  27    to work around different old braindamage in the old Linux/x86 ELF
  28    dynamic linker.  Sigh.  */
  29 weak_alias (__curbrk, ___brk_addr)
  30
  31 int
  32 __brk (void *addr)
  33 {
  34   void *newbrk;
  35
  36   {
  37     register long int res __asm__ ("$2");
  38
  39     asm ("move\t$4,%2\n\t"
  40          "syscall"              /* Perform the system call.  */
  41          : "=r" (res)
  42          : "0" (SYS_ify (brk)), "r" (addr)
  43          : "$4", "$7");
  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)