From: John Ogness john.ogness@linutronix.de
[ Upstream commit 36652d0f3bf34899e82d31a5fa9e2bdd02fd6381 ]
There is already panic_in_progress() and other_cpu_in_panic(), but checking if the current CPU is the panic CPU must still be open coded.
Add this_cpu_in_panic() to complete the set.
Signed-off-by: John Ogness john.ogness@linutronix.de Reviewed-by: Petr Mladek pmladek@suse.com Link: https://lore.kernel.org/r/20240207134103.1357162-8-john.ogness@linutronix.de Signed-off-by: Petr Mladek pmladek@suse.com Stable-dep-of: b1c4c67a5e90 ("printk: ringbuffer: Skip non-finalized records in panic") Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/printk/internal.h | 1 + kernel/printk/printk.c | 43 +++++++++++++++++++++------------------- 2 files changed, 24 insertions(+), 20 deletions(-)
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index 6c2afee5ef620..ac2d9750e5f81 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -130,6 +130,7 @@ struct printk_message { };
bool other_cpu_in_panic(void); +bool this_cpu_in_panic(void); bool printk_get_next_message(struct printk_message *pmsg, u64 seq, bool is_extended, bool may_supress);
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index d9420207282ac..b7e50f8438df3 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -347,6 +347,29 @@ static bool panic_in_progress(void) return unlikely(atomic_read(&panic_cpu) != PANIC_CPU_INVALID); }
+/* Return true if a panic is in progress on the current CPU. */ +bool this_cpu_in_panic(void) +{ + /* + * We can use raw_smp_processor_id() here because it is impossible for + * the task to be migrated to the panic_cpu, or away from it. If + * panic_cpu has already been set, and we're not currently executing on + * that CPU, then we never will be. + */ + return unlikely(atomic_read(&panic_cpu) == raw_smp_processor_id()); +} + +/* + * Return true if a panic is in progress on a remote CPU. + * + * On true, the local CPU should immediately release any printing resources + * that may be needed by the panic CPU. + */ +bool other_cpu_in_panic(void) +{ + return (panic_in_progress() && !this_cpu_in_panic()); +} + /* * This is used for debugging the mess that is the VT code by * keeping track if we have the console semaphore held. It's @@ -2601,26 +2624,6 @@ static int console_cpu_notify(unsigned int cpu) return 0; }
-/* - * Return true if a panic is in progress on a remote CPU. - * - * On true, the local CPU should immediately release any printing resources - * that may be needed by the panic CPU. - */ -bool other_cpu_in_panic(void) -{ - if (!panic_in_progress()) - return false; - - /* - * We can use raw_smp_processor_id() here because it is impossible for - * the task to be migrated to the panic_cpu, or away from it. If - * panic_cpu has already been set, and we're not currently executing on - * that CPU, then we never will be. - */ - return atomic_read(&panic_cpu) != raw_smp_processor_id(); -} - /** * console_lock - block the console subsystem from printing *