This is a note to let you know that I've just added the patch titled
printk: Add panic_in_progress helper
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
printk-add-panic_in_progress-helper.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 638bff97b02854768b03c7de106b677613c51560
Author: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx>
Date: Wed Feb 2 09:18:18 2022 -0800
printk: Add panic_in_progress helper
[ Upstream commit 77498617857f68496b360081dde1a492d40c28b2 ]
This will be used help avoid deadlocks during panics. Although it would
be better to include this in linux/panic.h, it would require that header
to include linux/atomic.h as well. On some architectures, this results
in a circular dependency as well. So instead add the helper directly to
printk.c.
Suggested-by: Petr Mladek <pmladek@xxxxxxxx>
Signed-off-by: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx>
Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>
Link: https://lore.kernel.org/r/20220202171821.179394-2-stephen.s.brennan@xxxxxxxxxx
Stable-dep-of: d04d5882cd67 ("printk: Disable passing console lock owner completely during panic()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 8b110b245d92c..de44ccf9743c1 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -258,6 +258,11 @@ static void __up_console_sem(unsigned long ip)
}
#define up_console_sem() __up_console_sem(_RET_IP_)
+static bool panic_in_progress(void)
+{
+ return unlikely(atomic_read(&panic_cpu) != PANIC_CPU_INVALID);
+}
+
/*
* This is used for debugging the mess that is the VT code by
* keeping track if we have the console semaphore held. It's
