1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_RISCV_EXTABLE_H 3 #define _ASM_RISCV_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 int insn, fixup; 20 short type, data; 21 }; 22 23 #define ARCH_HAS_RELATIVE_EXTABLE 24 25 #define swap_ex_entry_fixup(a, b, tmp, delta) \ 26 do { \ 27 (a)->fixup = (b)->fixup + (delta); \ 28 (b)->fixup = (tmp).fixup - (delta); \ 29 (a)->type = (b)->type; \ 30 (b)->type = (tmp).type; \ 31 (a)->data = (b)->data; \ 32 (b)->data = (tmp).data; \ 33 } while (0) 34 35 bool fixup_exception(struct pt_regs *regs); 36 37 #if defined(CONFIG_BPF_JIT) && defined(CONFIG_ARCH_RV64I) 38 bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs); 39 #else 40 static inline bool 41 ex_handler_bpf(const struct exception_table_entry *ex, 42 struct pt_regs *regs) 43 { 44 return false; 45 } 46 #endif 47 48 #endif 49