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

   1 /* brk system call for Linux/SH.
   2    Copyright (C) 1999-2015 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 /* This must be initialized data because commons can't have aliases.  */
  24 void *__curbrk = 0;
  25
  26 int
  27 __brk (void *addr)
  28 {
  29   void *newbrk;
  30   register long r3 asm ("%r3") = SYS_ify (brk);
  31   register long r4 asm ("%r4") = (long)addr;
  32
  33   asm volatile ("trapa #0x11\n\t" SYSCALL_INST_PAD
  34                 : "=z"(newbrk)
  35                 : "r" (r3), "r" (r4));
  36
  37   __curbrk = newbrk;
  38
  39   if (newbrk < addr)
  40     {
  41       __set_errno (ENOMEM);
  42       return -1;
  43     }
  44
  45   return 0;
  46 }
  47 weak_alias (__brk, brk)