[PATCH v2 06/11] cpu: Mark nmi_panic_self_stop() __noreturn

From: Josh Poimboeuf
Date: Wed Apr 12 2023 - 19:50:28 EST


In preparation for improving objtool's handling of weak noreturn
functions, mark nmi_panic_self_stop() __noreturn.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/include/asm/reboot.h | 1 -
arch/x86/kernel/reboot.c | 2 +-
include/linux/smp.h | 2 +-
kernel/panic.c | 2 +-
tools/objtool/check.c | 1 +
5 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/reboot.h b/arch/x86/include/asm/reboot.h
index bc5b4d788c08..9177b4354c3f 100644
--- a/arch/x86/include/asm/reboot.h
+++ b/arch/x86/include/asm/reboot.h
@@ -28,7 +28,6 @@ void __noreturn machine_real_restart(unsigned int type);
void cpu_emergency_disable_virtualization(void);

typedef void (*nmi_shootdown_cb)(int, struct pt_regs*);
-void nmi_panic_self_stop(struct pt_regs *regs);
void nmi_shootdown_cpus(nmi_shootdown_cb callback);
void run_crash_ipi_callback(struct pt_regs *regs);

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index d03c551defcc..3adbe97015c1 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -920,7 +920,7 @@ void run_crash_ipi_callback(struct pt_regs *regs)
}

/* Override the weak function in kernel/panic.c */
-void nmi_panic_self_stop(struct pt_regs *regs)
+void __noreturn nmi_panic_self_stop(struct pt_regs *regs)
{
while (1) {
/* If no CPU is preparing crash dump, we simply loop here. */
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 2a737b39cf0a..7b93504eed26 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -60,7 +60,7 @@ int smp_call_function_single_async(int cpu, struct __call_single_data *csd);
* Architecture-dependent code may override them.
*/
void __noreturn panic_smp_self_stop(void);
-void nmi_panic_self_stop(struct pt_regs *regs);
+void __noreturn nmi_panic_self_stop(struct pt_regs *regs);
void crash_smp_send_stop(void);

/*
diff --git a/kernel/panic.c b/kernel/panic.c
index 5e4982db8dc9..886d2ebd0a0d 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -151,7 +151,7 @@ void __weak __noreturn panic_smp_self_stop(void)
* Stop ourselves in NMI context if another CPU has already panicked. Arch code
* may override this to prepare for crash dumping, e.g. save regs info.
*/
-void __weak nmi_panic_self_stop(struct pt_regs *regs)
+void __weak __noreturn nmi_panic_self_stop(struct pt_regs *regs)
{
panic_smp_self_stop();
}
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 43946188cd2c..ed42717463f9 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -217,6 +217,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
"lbug_with_loc",
"machine_real_restart",
"make_task_dead",
+ "nmi_panic_self_stop",
"panic",
"panic_smp_self_stop",
"rest_init",
--
2.39.2