From: Stephen Brennan stephen.s.brennan@oracle.com
[ 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@suse.com Signed-off-by: Stephen Brennan stephen.s.brennan@oracle.com Reviewed-by: Petr Mladek pmladek@suse.com Reviewed-by: Sergey Senozhatsky senozhatsky@chromium.org Signed-off-by: Petr Mladek pmladek@suse.com Link: https://lore.kernel.org/r/20220202171821.179394-2-stephen.s.brennan@oracle.c... Stable-dep-of: d04d5882cd67 ("printk: Disable passing console lock owner completely during panic()") Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/printk/printk.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 17a310dcb6d96..94af80b7fa9b5 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