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glibc  2.9
brk.c
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00001 /* brk system call for Linux/SPARC.
00002    Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004    Contributed by Miguel de Icaza (miguel@nuclecu.unam.mx)
00005 
00006    The GNU C Library is free software; you can redistribute it and/or
00007    modify it under the terms of the GNU Lesser General Public
00008    License as published by the Free Software Foundation; either
00009    version 2.1 of the License, or (at your option) any later version.
00010 
00011    The GNU C Library is distributed in the hope that it will be useful,
00012    but WITHOUT ANY WARRANTY; without even the implied warranty of
00013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014    Lesser General Public License for more details.
00015 
00016    You should have received a copy of the GNU Lesser General Public
00017    License along with the GNU C Library; if not, write to the Free
00018    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00019    02111-1307 USA.  */
00020 
00021 #include <errno.h>
00022 #include <unistd.h>
00023 #include <sysdep.h>
00024 
00025 /* This must be initialized data because commons can't have aliases.  */
00026 void *__curbrk = 0;
00027 
00028 /* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
00029    to work around different old braindamage in the old Linux ELF dynamic
00030    linker.  */
00031 weak_alias (__curbrk, ___brk_addr)
00032 
00033 int
00034 __brk (void *addr)
00035 {
00036   void *newbrk;
00037 
00038   {
00039     register void *o0 __asm__("%o0") = addr;
00040     register int g1 __asm__("%g1") = __NR_brk;
00041     __asm ("t 0x10" : "=r"(o0) : "r"(g1), "0"(o0) : "cc");
00042     newbrk = o0;
00043   }
00044 
00045   __curbrk = newbrk;
00046 
00047   if (newbrk < addr)
00048     {
00049       __set_errno (ENOMEM);
00050       return -1;
00051     }
00052 
00053   return 0;
00054 }
00055 weak_alias (__brk, brk)