From: Peter Zijlstra peterz@infradead.org
[ Upstream commit f9cdf7ca57cada055f61ef6d0eb4db21c3f200db ]
vmlinux.o: warning: objtool: smp_stop_nmi_callback()+0x2b: unreachable instruction
0000 0000000000047cf0 <smp_stop_nmi_callback>: ... 0026 47d16: e8 00 00 00 00 call 47d1b <smp_stop_nmi_callback+0x2b> 47d17: R_X86_64_PLT32 stop_this_cpu-0x4 002b 47d1b: b8 01 00 00 00 mov $0x1,%eax
Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Acked-by: Josh Poimboeuf jpoimboe@redhat.com Link: https://lore.kernel.org/r/20220308154319.290905453@infradead.org Stable-dep-of: c0dd9245aa9e ("x86/microcode: Check CPU capabilities after late microcode update correctly") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/include/asm/processor.h | 2 +- arch/x86/kernel/process.c | 2 +- tools/objtool/check.c | 1 + 3 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 388541ec77aad..01bcbf8a25b29 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -839,7 +839,7 @@ bool xen_set_default_idle(void); #define xen_set_default_idle 0 #endif
-void stop_this_cpu(void *dummy); +void __noreturn stop_this_cpu(void *dummy); void microcode_check(void);
enum l1tf_mitigations { diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 5e17c3939dd1c..1cba09a9f1c13 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -720,7 +720,7 @@ bool xen_set_default_idle(void) } #endif
-void stop_this_cpu(void *dummy) +void __noreturn stop_this_cpu(void *dummy) { local_irq_disable(); /* diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 985bcc5cea8a4..ff47aed7ef6fe 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -180,6 +180,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "kunit_try_catch_throw", "xen_start_kernel", "cpu_bringup_and_idle", + "stop_this_cpu", };
if (!func)