arch/x86/include/asm/extable.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_EXTABLE_H
   3 #define _ASM_X86_EXTABLE_H
   4 /*
   5  * The exception table consists of triples of addresses relative to the
   6  * exception table entry itself. The first address is of an instruction
   7  * that is allowed to fault, the second is the target at which the program
   8  * should continue. The third is a handler function to deal with the fault
   9  * caused by the instruction in the first field.
  10  *
  11  * All the routines below use bits of fixup code that are out of line
  12  * with the main instruction path.  This means when everything is well,
  13  * we don't even have to jump over them.  Further, they do not intrude
  14  * on our cache or tlb entries.
  15  */
  16
  17 struct exception_table_entry {
  18         int insn, fixup, handler;
  19 };
  20 struct pt_regs;
  21
  22 #define ARCH_HAS_RELATIVE_EXTABLE
  23
  24 #define swap_ex_entry_fixup(a, b, tmp, delta)                   \
  25         do {                                                    \
  26                 (a)->fixup = (b)->fixup + (delta);              \
  27                 (b)->fixup = (tmp).fixup - (delta);             \
  28                 (a)->handler = (b)->handler + (delta);          \
  29                 (b)->handler = (tmp).handler - (delta);         \
  30         } while (0)
  31
  32 enum handler_type {
  33         EX_HANDLER_NONE,
  34         EX_HANDLER_FAULT,
  35         EX_HANDLER_UACCESS,
  36         EX_HANDLER_OTHER
  37 };
  38
  39 extern int fixup_exception(struct pt_regs *regs, int trapnr,
  40                            unsigned long error_code, unsigned long fault_addr);
  41 extern int fixup_bug(struct pt_regs *regs, int trapnr);
  42 extern enum handler_type ex_get_fault_handler_type(unsigned long ip);
  43 extern void early_fixup_exception(struct pt_regs *regs, int trapnr);
  44
  45 #endif