[tip: objtool/core] cpu: Mark nmi_panic_self_stop() __noreturn

[tip-bot2 for Josh Poimboeuf]

The following commit has been merged into the objtool/core branch of tip:

Commit-ID:     27dea14c7f05106f39850a9239874cd38703b405
Gitweb:        https://git.kernel.org/tip/27dea14c7f05106f39850a9239874cd38703b405
Author:        Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate:    Wed, 12 Apr 2023 16:49:36 -07:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 14 Apr 2023 17:31:26 +02:00

cpu: Mark nmi_panic_self_stop() __noreturn

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

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/316fc6dfab5a8c4e024c7185484a1ee5fb0afb79.1681342859.git.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 bc5b4d7..9177b43 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 d03c551..3adbe97 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 2a737b3..7b93504 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 5e4982d..886d2eb 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 4b52ed6..8d073bf 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",