brk.c 1.2 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445
  1. /* brk system call for Linux/x86_64.
  2. Copyright (C) 1995, 1996, 2000 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, see
  14. <http://www.gnu.org/licenses/>. */
  15. #include <errno.h>
  16. #include <unistd.h>
  17. #include <sys/syscall.h>
  18. /* This must be initialized data because commons can't have aliases. */
  19. void *__curbrk attribute_hidden = 0;
  20. int brk(void *addr)
  21. {
  22. void *newbrk;
  23. __asm__ ("syscall\n"
  24. : "=a" (newbrk)
  25. : "0" (__NR_brk), "D" (addr)
  26. : "r11", "rcx"
  27. );
  28. __curbrk = newbrk;
  29. if (newbrk < addr) {
  30. __set_errno(ENOMEM);
  31. return -1;
  32. }
  33. return 0;
  34. }
  35. libc_hidden_def(brk)