printk: Add panic_in_progress helper

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.com
This commit is contained in:
Stephen Brennan 2022-02-02 09:18:18 -08:00 committed by Petr Mladek
parent a229327733
commit 7749861785
1 changed files with 5 additions and 0 deletions

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@ -256,6 +256,11 @@ 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