stackprotector.h 1.0 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * GCC stack protector support.
  4. *
  5. * Stack protector works by putting predefined pattern at the start of
  6. * the stack frame and verifying that it hasn't been overwritten when
  7. * returning from the function. The pattern is called stack canary and
  8. * on LoongArch gcc expects it to be defined by a global variable called
  9. * "__stack_chk_guard".
  10. */
  11. #ifndef _ASM_STACKPROTECTOR_H
  12. #define _ASM_STACKPROTECTOR_H
  13. #include <linux/random.h>
  14. #include <linux/version.h>
  15. extern unsigned long __stack_chk_guard;
  16. /*
  17. * Initialize the stackprotector canary value.
  18. *
  19. * NOTE: this must only be called from functions that never return,
  20. * and it must always be inlined.
  21. */
  22. static __always_inline void boot_init_stack_canary(void)
  23. {
  24. unsigned long canary;
  25. /* Try to get a semi random initial value. */
  26. get_random_bytes(&canary, sizeof(canary));
  27. canary ^= LINUX_VERSION_CODE;
  28. current->stack_canary = canary;
  29. __stack_chk_guard = current->stack_canary;
  30. }
  31. #endif /* _ASM_STACKPROTECTOR_H */