brk.c 1.7 KB

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  1. /* brk system call for Linux/VAX.
  2. Copyright (C) 2000, 2005 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, write to the Free
  14. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  15. 02111-1307 USA. */
  16. #include <errno.h>
  17. #include <unistd.h>
  18. #include <sys/syscall.h>
  19. /* This must be initialized data because commons can't have aliases. */
  20. void *__curbrk attribute_hidden = NULL;
  21. libc_hidden_proto(brk)
  22. int
  23. brk (void *addr)
  24. {
  25. register unsigned long int result __asm__ ("%%r0");
  26. __asm__ (
  27. " pushl %%ap \n" /* Start frame */
  28. " pushl %2 \n" /* New top address we wish to get */
  29. " pushl $1 \n" /* One argument */
  30. " movl %%sp, %%ap \n" /* Finish frame */
  31. " chmk %1 \n" /* Perform the system call */
  32. " addl2 $8, %%sp \n" /* Remove pushed arg */
  33. " movl (%%sp)+, %%ap \n" /* Get back %AP */
  34. : "=r" (result)
  35. : "0" (__NR_brk),
  36. "g" (addr));
  37. if ((void *) result < addr) {
  38. __set_errno (ENOMEM);
  39. return -1;
  40. } else
  41. __curbrk = (void *) result;
  42. return 0;
  43. }
  44. libc_hidden_def(brk)