linux-kernel - [PATCH AUTOSEL 6.8 19/98] printk: For @suppress_panic

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Date: Fri, 29 Mar 2024 08:36:50 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: John Ogness <john.ogness@...utronix.de>,
	Petr Mladek <pmladek@...e.com>,
	Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 6.8 19/98] printk: For @suppress_panic_printk check for other CPU in panic

From: John Ogness <john.ogness@...utronix.de>

[ Upstream commit 0ab7cdd00491b532591ef065be706301de7e448f ]

Currently @suppress_panic_printk is checked along with
non-matching @panic_cpu and current CPU. This works
because @suppress_panic_printk is only set when
panic_in_progress() is true.

Rather than relying on the @suppress_panic_printk semantics,
use the concise helper function other_cpu_in_progress(). The
helper function exists to avoid open coding such tests.

Signed-off-by: John Ogness <john.ogness@...utronix.de>
Reviewed-by: Petr Mladek <pmladek@...e.com>
Link: https://lore.kernel.org/r/20240207134103.1357162-7-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@...e.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 kernel/printk/printk.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index f2444b581e16c..d9f20d222293b 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2270,8 +2270,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 	if (unlikely(suppress_printk))
 		return 0;
 
-	if (unlikely(suppress_panic_printk) &&
-	    atomic_read(&panic_cpu) != raw_smp_processor_id())
+	if (unlikely(suppress_panic_printk) && other_cpu_in_panic())
 		return 0;
 
 	if (level == LOGLEVEL_SCHED) {
-- 
2.43.0