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 };
  22
  23 #define ARCH_HAS_RELATIVE_EXTABLE
  24
  25 static inline bool in_bpf_jit(struct pt_regs *regs)
  26 {
  27         if (!IS_ENABLED(CONFIG_BPF_JIT))
  28                 return false;
  29
  30         return regs->pc >= BPF_JIT_REGION_START &&
  31                regs->pc < BPF_JIT_REGION_END;
  32 }
  33
  34 #ifdef CONFIG_BPF_JIT
  35 int arm64_bpf_fixup_exception(const struct exception_table_entry *ex,
  36                               struct pt_regs *regs);
  37 #else /* !CONFIG_BPF_JIT */
  38 static inline
  39 int arm64_bpf_fixup_exception(const struct exception_table_entry *ex,
  40                               struct pt_regs *regs)
  41 {
  42         return 0;
  43 }
  44 #endif /* !CONFIG_BPF_JIT */
  45
  46 extern int fixup_exception(struct pt_regs *regs);
  47 #endif