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

   1 /* brk system call for Linux/ARM.
   2    Copyright (C) 1995, 1996 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 /* This must be initialized data because commons can't have aliases.  */
  25 void *__curbrk = 0;
  26
  27 int
  28 __brk (void *addr)
  29 {
  30   void *newbrk;
  31
  32   asm ("mov a1, %1\n"   /* save the argment in r0 */
  33        "swi %2\n"       /* do the system call */
  34        "mov %0, a1;"    /* keep the return value */
  35        : "=r"(newbrk)
  36        : "r"(addr), "i" (SYS_ify (brk))
  37        : "a1");
  38
  39   __curbrk = newbrk;
  40
  41   if (newbrk < addr)
  42     {
  43       __set_errno (ENOMEM);
  44       return -1;
  45     }
  46
  47   return 0;
  48 }
  49 weak_alias (__brk, brk)