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glibc  2.9
brk.c
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00001 /* brk system call for Linux/SH.
00002    Copyright (C) 1999, 2000, 2003 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <errno.h>
00021 #include <unistd.h>
00022 #include <sysdep.h>
00023 
00024 /* This must be initialized data because commons can't have aliases.  */
00025 void *__curbrk = 0;
00026 
00027 int
00028 __brk (void *addr)
00029 {
00030   void *newbrk;
00031   register long r3 asm ("%r3") = SYS_ify (brk);
00032   register long r4 asm ("%r4") = (long)addr;
00033 
00034   asm volatile ("trapa #0x11\n\t" SYSCALL_INST_PAD
00035               : "=z"(newbrk) 
00036               : "r" (r3), "r" (r4));
00037 
00038   __curbrk = newbrk;
00039 
00040   if (newbrk < addr)
00041     {
00042       __set_errno (ENOMEM);
00043       return -1;
00044     }
00045 
00046   return 0;
00047 }
00048 weak_alias (__brk, brk)