brk.c 1.3 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546
  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, 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 = 0;
  21. int brk(void *addr)
  22. {
  23. void *newbrk;
  24. __asm__ ("syscall\n"
  25. : "=a" (newbrk)
  26. : "0" (__NR_brk), "D" (addr)
  27. : "r11", "rcx"
  28. );
  29. __curbrk = newbrk;
  30. if (newbrk < addr) {
  31. __set_errno(ENOMEM);
  32. return -1;
  33. }
  34. return 0;
  35. }
  36. libc_hidden_def(brk)