linux-stable/arch/x86/include/asm/extable.h
Borislav Petkov 2028a255f4 x86/extable: Annotate ex_handler_msr_mce() as a dead end
Fix

  vmlinux.o: warning: objtool: fixup_exception+0x2d6: unreachable instruction

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220520192729.23969-1-bp@alien8.de
2022-05-27 12:34:45 +02:00

61 lines
1.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_EXTABLE_H
#define _ASM_X86_EXTABLE_H
#include <asm/extable_fixup_types.h>
/*
* The exception table consists of two addresses relative to the
* exception table entry itself and a type selector field.
*
* The first address is of an instruction that is allowed to fault, the
* second is the target at which the program should continue.
*
* The type entry is used by fixup_exception() to select the handler to
* deal with the fault caused by the instruction in the first field.
*
* 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, data;
};
struct pt_regs;
#define ARCH_HAS_RELATIVE_EXTABLE
#define swap_ex_entry_fixup(a, b, tmp, delta) \
do { \
(a)->fixup = (b)->fixup + (delta); \
(b)->fixup = (tmp).fixup - (delta); \
(a)->data = (b)->data; \
(b)->data = (tmp).data; \
} while (0)
extern int fixup_exception(struct pt_regs *regs, int trapnr,
unsigned long error_code, unsigned long fault_addr);
extern int fixup_bug(struct pt_regs *regs, int trapnr);
extern int ex_get_fixup_type(unsigned long ip);
extern void early_fixup_exception(struct pt_regs *regs, int trapnr);
#ifdef CONFIG_X86_MCE
extern void __noreturn ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr);
#else
static inline void __noreturn ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr)
{
for (;;)
cpu_relax();
}
#endif
#if defined(CONFIG_BPF_JIT) && defined(CONFIG_X86_64)
bool ex_handler_bpf(const struct exception_table_entry *x, struct pt_regs *regs);
#else
static inline bool ex_handler_bpf(const struct exception_table_entry *x,
struct pt_regs *regs) { return false; }
#endif
#endif