1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_EXTABLE_H 3 #define _ASM_X86_EXTABLE_H 4 5 #include <asm/extable_fixup_types.h> 6 7 /* 8 * The exception table consists of two addresses relative to the 9 * exception table entry itself and a type selector field. 10 * 11 * The first address is of an instruction that is allowed to fault, the 12 * second is the target at which the program should continue. 13 * 14 * The type entry is used by fixup_exception() to select the handler to 15 * deal with the fault caused by the instruction in the first field. 16 * 17 * All the routines below use bits of fixup code that are out of line 18 * with the main instruction path. This means when everything is well, 19 * we don't even have to jump over them. Further, they do not intrude 20 * on our cache or tlb entries. 21 */ 22 23 struct exception_table_entry { 24 int insn, fixup, data; 25 }; 26 struct pt_regs; 27 28 #define ARCH_HAS_RELATIVE_EXTABLE 29 30 #define swap_ex_entry_fixup(a, b, tmp, delta) \ 31 do { \ 32 (a)->fixup = (b)->fixup + (delta); \ 33 (b)->fixup = (tmp).fixup - (delta); \ 34 (a)->data = (b)->data; \ 35 (b)->data = (tmp).data; \ 36 } while (0) 37 38 extern int fixup_exception(struct pt_regs *regs, int trapnr, 39 unsigned long error_code, unsigned long fault_addr); 40 extern int ex_get_fixup_type(unsigned long ip); 41 extern void early_fixup_exception(struct pt_regs *regs, int trapnr); 42 43 #ifdef CONFIG_X86_MCE 44 extern void __noreturn ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr); 45 #else 46 static inline void __noreturn ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr) 47 { 48 for (;;) 49 cpu_relax(); 50 } 51 #endif 52 53 #if defined(CONFIG_BPF_JIT) && defined(CONFIG_X86_64) 54 bool ex_handler_bpf(const struct exception_table_entry *x, struct pt_regs *regs); 55 #else 56 static inline bool ex_handler_bpf(const struct exception_table_entry *x, 57 struct pt_regs *regs) { return false; } 58 #endif 59 60 #endif 61