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 bool insn_may_access_user(unsigned long addr, unsigned long esr); 37 38 #ifdef CONFIG_BPF_JIT 39 bool ex_handler_bpf(const struct exception_table_entry *ex, 40 struct pt_regs *regs); 41 #else /* !CONFIG_BPF_JIT */ 42 static inline 43 bool ex_handler_bpf(const struct exception_table_entry *ex, 44 struct pt_regs *regs) 45 { 46 return false; 47 } 48 #endif /* !CONFIG_BPF_JIT */ 49 50 bool fixup_exception(struct pt_regs *regs, unsigned long esr); 51 #endif 52