[PATCH v2 05/11] cpu: Mark panic_smp_self_stop() __noreturn

From: Josh Poimboeuf
Date: Wed Apr 12 2023 - 19:50:25 EST


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

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/arm/kernel/smp.c | 2 +-
arch/arm64/include/asm/smp.h | 1 -
arch/arm64/kernel/smp.c | 2 +-
arch/powerpc/kernel/setup_64.c | 2 +-
include/linux/smp.h | 2 +-
kernel/panic.c | 2 +-
tools/objtool/check.c | 1 +
7 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index d6be4507d22d..f4a4ac028b6b 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -779,7 +779,7 @@ void smp_send_stop(void)
* kdump fails. So split out the panic_smp_self_stop() and add
* set_cpu_online(smp_processor_id(), false).
*/
-void panic_smp_self_stop(void)
+void __noreturn panic_smp_self_stop(void)
{
pr_debug("CPU %u will stop doing anything useful since another CPU has paniced\n",
smp_processor_id());
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index 07f4ea1490f4..f2d26235bfb4 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -143,7 +143,6 @@ bool cpus_are_stuck_in_kernel(void);

extern void crash_smp_send_stop(void);
extern bool smp_crash_stop_failed(void);
-extern void panic_smp_self_stop(void);

#endif /* ifndef __ASSEMBLY__ */

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 07d156fddb5f..05fe797e4203 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -830,7 +830,7 @@ static void __noreturn local_cpu_stop(void)
* that cpu_online_mask gets correctly updated and smp_send_stop() can skip
* CPUs that have already stopped themselves.
*/
-void panic_smp_self_stop(void)
+void __noreturn panic_smp_self_stop(void)
{
local_cpu_stop();
}
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index b2e0d3ce4261..246201d0d879 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -480,7 +480,7 @@ void early_setup_secondary(void)

#endif /* CONFIG_SMP */

-void panic_smp_self_stop(void)
+void __noreturn panic_smp_self_stop(void)
{
hard_irq_disable();
spin_begin();
diff --git a/include/linux/smp.h b/include/linux/smp.h
index a80ab58ae3f1..2a737b39cf0a 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -59,7 +59,7 @@ int smp_call_function_single_async(int cpu, struct __call_single_data *csd);
* Cpus stopping functions in panic. All have default weak definitions.
* Architecture-dependent code may override them.
*/
-void panic_smp_self_stop(void);
+void __noreturn panic_smp_self_stop(void);
void 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 5cfea8302d23..5e4982db8dc9 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -141,7 +141,7 @@ EXPORT_SYMBOL(panic_blink);
/*
* Stop ourself in panic -- architecture code may override this
*/
-void __weak panic_smp_self_stop(void)
+void __weak __noreturn panic_smp_self_stop(void)
{
while (1)
cpu_relax();
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 4e89342dd8fb..43946188cd2c 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -218,6 +218,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
"machine_real_restart",
"make_task_dead",
"panic",
+ "panic_smp_self_stop",
"rest_init",
"rewind_stack_and_make_dead",
"sev_es_terminate",
--
2.39.2