[PATCH 1/2] s390/smp: Mark pcpu_delegate as __noreturn

[Thorsten Blum <thorsten.blum@linux.dev>]

pcpu_delegate() never returns to its caller. If the target CPU is the
current CPU, it calls __pcpu_delegate(), whose delegate function is not
supposed to return. In any case, even if __pcpu_delegate() unexpectedly
returns, pcpu_delegate() sends SIGP_STOP to the current CPU and waits
in an infinite loop. Annotate pcpu_delegate() with the __noreturn
attribute to improve compiler optimizations.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 arch/s390/kernel/smp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index da84c0dc6b7e..93ac451db6f9 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -305,9 +305,9 @@ static void __pcpu_delegate(pcpu_delegate_fn *func, void *data)
 	func(data);	/* should not return */
 }
 
-static void pcpu_delegate(struct pcpu *pcpu, int cpu,
-			  pcpu_delegate_fn *func,
-			  void *data, unsigned long stack)
+static void __noreturn pcpu_delegate(struct pcpu *pcpu, int cpu,
+				     pcpu_delegate_fn *func,
+				     void *data, unsigned long stack)
 {
 	struct lowcore *lc, *abs_lc;
 	unsigned int source_cpu;
-- 
2.51.0