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

   1 /* brk system call for Linux/SH.
   2    Copyright (C) 1999, 2000, 2003 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   register long r3 asm ("%r3") = SYS_ify (brk);
  32   register long r4 asm ("%r4") = (long)addr;
  33
  34   asm volatile ("trapa #0x11\n\t" SYSCALL_INST_PAD
  35                 : "=z"(newbrk)
  36                 : "r" (r3), "r" (r4));
  37
  38   __curbrk = newbrk;
  39
  40   if (newbrk < addr)
  41     {
  42       __set_errno (ENOMEM);
  43       return -1;
  44     }
  45
  46   return 0;
  47 }
  48 weak_alias (__brk, brk)