vfork.S 1.6 KB

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  1. /* Copyright (C) 2005 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, see
  13. <http://www.gnu.org/licenses/>. */
  14. #include <tcb-offsets.h>
  15. /* Save the PID value. */
  16. #define SAVE_PID \
  17. str lr, [sp, #-4]!; /* Save LR. */ \
  18. mov r0, #0xffff0fff; /* Point to the high page. */ \
  19. mov lr, pc; /* Save our return address. */ \
  20. sub pc, r0, #31; /* Jump to the TLS entry. */ \
  21. ldr lr, [sp], #4; /* Restore LR. */ \
  22. mov r2, r0; /* Save the TLS addr in r2. */ \
  23. ldr r3, [r2, #PID_OFFSET]; /* Load the saved PID. */ \
  24. rsbs r0, r3, #0; /* Negate it. */ \
  25. moveq r0, #0x80000000; /* Use 0x80000000 if it was 0. */ \
  26. str r0, [r2, #PID_OFFSET] /* Store the temporary PID. */
  27. /* Restore the old PID value in the parent. */
  28. #define RESTORE_PID \
  29. cmp r0, #0; /* If we are the parent... */ \
  30. strne r3, [r2, #PID_OFFSET] /* ... restore the saved PID. */
  31. #include "../../../../../../../libc/sysdeps/linux/arm/vfork.S"