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- /* brk system call for Linux/i386.
- Copyright (C) 1995, 1996, 2000 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
- #include <errno.h>
- #include <unistd.h>
- #include <sys/syscall.h>
- #ifndef __ptrvalue
- #define __ptrvalue
- #endif
- /* This must be initialized data because commons can't have aliases. */
- void *___brk_addr = 0;
- int brk (void *addr)
- {
- void *newbrk, *scratch;
- asm ("movl %%ebx, %1\n" /* Save %ebx in scratch register. */
- "movl %3, %%ebx\n" /* Put ADDR in %ebx to be syscall arg. */
- "int $0x80 # %2\n" /* Perform the system call. */
- "movl %1, %%ebx\n" /* Restore %ebx from scratch register. */
- : "=a" (newbrk), "=r" (scratch)
- : "0" (__NR_brk), "g" (__ptrvalue (addr)));
- ___brk_addr = newbrk;
- if (newbrk < addr)
- {
- __set_errno (ENOMEM);
- return -1;
- }
- return 0;
- }
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