From 2028a255f4df3af9e759f01f958d3237f825f256 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 20 May 2022 21:27:29 +0200 Subject: [PATCH] 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 Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220520192729.23969-1-bp@alien8.de --- arch/x86/include/asm/extable.h | 8 ++++++-- tools/objtool/check.c | 1 + 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/extable.h b/arch/x86/include/asm/extable.h index 155c991ba95e..eeed395c3177 100644 --- a/arch/x86/include/asm/extable.h +++ b/arch/x86/include/asm/extable.h @@ -42,9 +42,13 @@ 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 ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr); +extern void __noreturn ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr); #else -static inline void ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr) { } +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) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 7a187dae2fcf..864bb9dd3584 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -187,6 +187,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "__invalid_creds", "cpu_startup_entry", "__ubsan_handle_builtin_unreachable", + "ex_handler_msr_mce", }; if (!func)