arch/arm64/include/asm/extable.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_EXTABLE_H
   3 #define __ASM_EXTABLE_H
   4
   5 /*
   6  * The exception table consists of pairs of relative offsets: the first
   7  * is the relative offset to an instruction that is allowed to fault,
   8  * and the second is the relative offset at which the program should
   9  * continue. No registers are modified, so it is entirely up to the
  10  * continuation code to figure out what to do.
  11  *
  12  * All the routines below use bits of fixup code that are out of line
  13  * with the main instruction path.  This means when everything is well,
  14  * we don't even have to jump over them.  Further, they do not intrude
  15  * on our cache or tlb entries.
  16  */
  17
  18 struct exception_table_entry
  19 {
  20         int insn, fixup;
  21         short type, data;
  22 };
  23
  24 #define ARCH_HAS_RELATIVE_EXTABLE
  25
  26 #define swap_ex_entry_fixup(a, b, tmp, delta)           \
  27 do {                                                    \
  28         (a)->fixup = (b)->fixup + (delta);              \
  29         (b)->fixup = (tmp).fixup - (delta);             \
  30         (a)->type = (b)->type;                          \
  31         (b)->type = (tmp).type;                         \
  32         (a)->data = (b)->data;                          \
  33         (b)->data = (tmp).data;                         \
  34 } while (0)
  35
  36 #ifdef CONFIG_BPF_JIT
  37 bool ex_handler_bpf(const struct exception_table_entry *ex,
  38                     struct pt_regs *regs);
  39 #else /* !CONFIG_BPF_JIT */
  40 static inline
  41 bool ex_handler_bpf(const struct exception_table_entry *ex,
  42                     struct pt_regs *regs)
  43 {
  44         return false;
  45 }
  46 #endif /* !CONFIG_BPF_JIT */
  47
  48 bool fixup_exception(struct pt_regs *regs);
  49 #endif