linux-kernel - [PATCH v2 6/9] printk/nbcon: use panic_on_this

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Message-ID: <20250825022947.1596226-7-wangjinchao600@gmail.com>
Date: Mon, 25 Aug 2025 10:29:34 +0800
From: Jinchao Wang <wangjinchao600@...il.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
	Baoquan He <bhe@...hat.com>,
	Yury Norov <yury.norov@...il.com>,
	Qianqiang Liu <qianqiang.liu@....com>,
	Simona Vetter <simona@...ll.ch>,
	Helge Deller <deller@....de>,
	Petr Mladek <pmladek@...e.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	John Ogness <john.ogness@...utronix.de>,
	Sergey Senozhatsky <senozhatsky@...omium.org>,
	Vivek Goyal <vgoyal@...hat.com>,
	Dave Young <dyoung@...hat.com>,
	Kees Cook <kees@...nel.org>,
	Tony Luck <tony.luck@...el.com>,
	"Guilherme G. Piccoli" <gpiccoli@...lia.com>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	Ville Syrjälä <ville.syrjala@...ux.intel.com>,
	Shixiong Ou <oushixiong@...inos.cn>,
	Jinchao Wang <wangjinchao600@...il.com>,
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	Douglas Anderson <dianders@...omium.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Anna Schumaker <anna.schumaker@...cle.com>,
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	Max Kellermann <max.kellermann@...os.com>,
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	Thorsten Blum <thorsten.blum@...ux.dev>,
	Yicong Yang <yangyicong@...ilicon.com>,
	linux-fbdev@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
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	linux-hardening@...r.kernel.org,
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Subject: [PATCH v2 6/9] printk/nbcon: use panic_on_this_cpu() helper

nbcon_context_try_acquire() compared panic_cpu directly with
smp_processor_id().  This open-coded check is now provided by
panic_on_this_cpu().

Switch to panic_on_this_cpu() to simplify the code and improve readability.

Signed-off-by: Jinchao Wang <wangjinchao600@...il.com>
---
 kernel/printk/nbcon.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
index 646801813415..7490865e2f44 100644
--- a/kernel/printk/nbcon.c
+++ b/kernel/printk/nbcon.c
@@ -2,6 +2,7 @@
 // Copyright (C) 2022 Linutronix GmbH, John Ogness
 // Copyright (C) 2022 Intel, Thomas Gleixner
 
+#include "linux/panic.h"
 #include <linux/atomic.h>
 #include <linux/bug.h>
 #include <linux/console.h>
@@ -589,7 +590,6 @@ static struct printk_buffers panic_nbcon_pbufs;
  */
 static bool nbcon_context_try_acquire(struct nbcon_context *ctxt, bool is_reacquire)
 {
-	unsigned int cpu = smp_processor_id();
 	struct console *con = ctxt->console;
 	struct nbcon_state cur;
 	int err;
@@ -614,7 +614,7 @@ static bool nbcon_context_try_acquire(struct nbcon_context *ctxt, bool is_reacqu
 	/* Acquire succeeded. */
 
 	/* Assign the appropriate buffer for this context. */
-	if (atomic_read(&panic_cpu) == cpu)
+	if (panic_on_this_cpu())
 		ctxt->pbufs = &panic_nbcon_pbufs;
 	else
 		ctxt->pbufs = con->pbufs;
-- 
2.43.0