arch/x86/include/asm/text-patching.h

   1 #ifndef _ASM_X86_TEXT_PATCHING_H
   2 #define _ASM_X86_TEXT_PATCHING_H
   3
   4 #include <linux/types.h>
   5 #include <linux/stddef.h>
   6 #include <asm/ptrace.h>
   7
   8 struct paravirt_patch_site;
   9 #ifdef CONFIG_PARAVIRT
  10 void apply_paravirt(struct paravirt_patch_site *start,
  11                     struct paravirt_patch_site *end);
  12 #else
  13 static inline void apply_paravirt(struct paravirt_patch_site *start,
  14                                   struct paravirt_patch_site *end)
  15 {}
  16 #define __parainstructions      NULL
  17 #define __parainstructions_end  NULL
  18 #endif
  19
  20 extern void *text_poke_early(void *addr, const void *opcode, size_t len);
  21
  22 /*
  23  * Clear and restore the kernel write-protection flag on the local CPU.
  24  * Allows the kernel to edit read-only pages.
  25  * Side-effect: any interrupt handler running between save and restore will have
  26  * the ability to write to read-only pages.
  27  *
  28  * Warning:
  29  * Code patching in the UP case is safe if NMIs and MCE handlers are stopped and
  30  * no thread can be preempted in the instructions being modified (no iret to an
  31  * invalid instruction possible) or if the instructions are changed from a
  32  * consistent state to another consistent state atomically.
  33  * On the local CPU you need to be protected again NMI or MCE handlers seeing an
  34  * inconsistent instruction while you patch.
  35  */
  36 extern void *text_poke(void *addr, const void *opcode, size_t len);
  37 extern int poke_int3_handler(struct pt_regs *regs);
  38 extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
  39
  40 #endif /* _ASM_X86_TEXT_PATCHING_H */