diff options
Diffstat (limited to 'arch/s390/include/asm/extable.h')
-rw-r--r-- | arch/s390/include/asm/extable.h | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/s390/include/asm/extable.h b/arch/s390/include/asm/extable.h new file mode 100644 index 000000000..af6ba5274 --- /dev/null +++ b/arch/s390/include/asm/extable.h @@ -0,0 +1,72 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __S390_EXTABLE_H +#define __S390_EXTABLE_H + +#include <asm/ptrace.h> +#include <linux/compiler.h> + +/* + * The exception table consists of three addresses: + * + * - Address of an instruction that is allowed to fault. + * - Address at which the program should continue. + * - Optional address of handler that takes pt_regs * argument and runs in + * interrupt context. + * + * No registers are modified, so it is entirely up to the continuation code + * to figure out what to do. + * + * All the routines below use bits of fixup code that are out of line + * with the main instruction path. This means when everything is well, + * we don't even have to jump over them. Further, they do not intrude + * on our cache or tlb entries. + */ + +struct exception_table_entry +{ + int insn, fixup; + short type, data; +}; + +extern struct exception_table_entry *__start_amode31_ex_table; +extern struct exception_table_entry *__stop_amode31_ex_table; + +const struct exception_table_entry *s390_search_extables(unsigned long addr); + +static inline unsigned long extable_fixup(const struct exception_table_entry *x) +{ + return (unsigned long)&x->fixup + x->fixup; +} + +#define ARCH_HAS_RELATIVE_EXTABLE + +static inline void swap_ex_entry_fixup(struct exception_table_entry *a, + struct exception_table_entry *b, + struct exception_table_entry tmp, + int delta) +{ + a->fixup = b->fixup + delta; + b->fixup = tmp.fixup - delta; + a->type = b->type; + b->type = tmp.type; + a->data = b->data; + b->data = tmp.data; +} +#define swap_ex_entry_fixup swap_ex_entry_fixup + +#ifdef CONFIG_BPF_JIT + +bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs); + +#else /* !CONFIG_BPF_JIT */ + +static inline bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs) +{ + return false; +} + +#endif /* CONFIG_BPF_JIT */ + +bool fixup_exception(struct pt_regs *regs); + +#endif |