[PATCH] lib/smp_processor_id: use preemptible() macro

From: Tetsuo Handa
Date: Thu Jun 23 2022 - 10:19:40 EST


preemptible() is unconditional 0 if CONFIG_PREEMPT_COUNT=n, and is
(preempt_count() == 0 && !irqs_disabled()) if CONFIG_PREEMPT_COUNT=y.

Although check_preemption_disabled() depends on CONFIG_PREEMPT_COUNT=y,
the naming implies whether preemption is already disabled. Thus, let's
make check_preemption_disabled() safe even if CONFIG_PREEMPT_COUNT=n.

Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
---
lib/smp_processor_id.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index 046ac6297c78..5bb0783ce038 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -13,10 +13,7 @@ unsigned int check_preemption_disabled(const char *what1, const char *what2)
{
int this_cpu = raw_smp_processor_id();

- if (likely(preempt_count()))
- goto out;
-
- if (irqs_disabled())
+ if (likely(!preemptible()))
goto out;

if (is_percpu_thread())
--
2.18.4