1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __S390_EXTABLE_H 3 #define __S390_EXTABLE_H 4 5 #include <asm/ptrace.h> 6 #include <linux/compiler.h> 7 8 /* 9 * The exception table consists of three addresses: 10 * 11 * - Address of an instruction that is allowed to fault. 12 * - Address at which the program should continue. 13 * - Optional address of handler that takes pt_regs * argument and runs in 14 * interrupt context. 15 * 16 * No registers are modified, so it is entirely up to the continuation code 17 * to figure out what to do. 18 * 19 * All the routines below use bits of fixup code that are out of line 20 * with the main instruction path. This means when everything is well, 21 * we don't even have to jump over them. Further, they do not intrude 22 * on our cache or tlb entries. 23 */ 24 25 struct exception_table_entry 26 { 27 int insn, fixup; 28 short type, data; 29 }; 30 31 extern struct exception_table_entry *__start_amode31_ex_table; 32 extern struct exception_table_entry *__stop_amode31_ex_table; 33 34 const struct exception_table_entry *s390_search_extables(unsigned long addr); 35 36 static inline unsigned long extable_fixup(const struct exception_table_entry *x) 37 { 38 return (unsigned long)&x->fixup + x->fixup; 39 } 40 41 #define ARCH_HAS_RELATIVE_EXTABLE 42 43 static inline void swap_ex_entry_fixup(struct exception_table_entry *a, 44 struct exception_table_entry *b, 45 struct exception_table_entry tmp, 46 int delta) 47 { 48 a->fixup = b->fixup + delta; 49 b->fixup = tmp.fixup - delta; 50 a->type = b->type; 51 b->type = tmp.type; 52 a->data = b->data; 53 b->data = tmp.data; 54 } 55 #define swap_ex_entry_fixup swap_ex_entry_fixup 56 57 #ifdef CONFIG_BPF_JIT 58 59 bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs); 60 61 #else /* !CONFIG_BPF_JIT */ 62 63 static inline bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs) 64 { 65 return false; 66 } 67 68 #endif /* CONFIG_BPF_JIT */ 69 70 bool fixup_exception(struct pt_regs *regs); 71 72 #endif 73