From: Jinchao Wang <wangjinchao600@gmail.com>
To: "Andrew Morton" <akpm@linux-foundation.org>,
"Baoquan He" <bhe@redhat.com>,
"Yury Norov" <yury.norov@gmail.com>,
"Qianqiang Liu" <qianqiang.liu@163.com>,
"Simona Vetter" <simona@ffwll.ch>, "Helge Deller" <deller@gmx.de>,
"Petr Mladek" <pmladek@suse.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"John Ogness" <john.ogness@linutronix.de>,
"Sergey Senozhatsky" <senozhatsky@chromium.org>,
"Vivek Goyal" <vgoyal@redhat.com>,
"Dave Young" <dyoung@redhat.com>, "Kees Cook" <kees@kernel.org>,
"Tony Luck" <tony.luck@intel.com>,
"Guilherme G. Piccoli" <gpiccoli@igalia.com>,
"Thomas Zimmermann" <tzimmermann@suse.de>,
"Ville Syrjälä" <ville.syrjala@linux.intel.com>,
"Shixiong Ou" <oushixiong@kylinos.cn>,
"Jinchao Wang" <wangjinchao600@gmail.com>,
"Zsolt Kajtar" <soci@c64.rulez.org>,
"Ingo Molnar" <mingo@kernel.org>,
"Nam Cao" <namcao@linutronix.de>,
"Jonathan Cameron" <Jonathan.Cameron@huawei.com>,
"Joel Fernandes" <joelagnelf@nvidia.com>,
"Joel Granados" <joel.granados@kernel.org>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
"Sohil Mehta" <sohil.mehta@intel.com>,
"Feng Tang" <feng.tang@linux.alibaba.com>,
"Sravan Kumar Gundu" <sravankumarlpu@gmail.com>,
"Douglas Anderson" <dianders@chromium.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Anna Schumaker" <anna.schumaker@oracle.com>,
"Darrick J. Wong" <djwong@kernel.org>,
"Max Kellermann" <max.kellermann@ionos.com>,
"Yunhui Cui" <cuiyunhui@bytedance.com>,
"Tejun Heo" <tj@kernel.org>,
"Luo Gengkun" <luogengkun@huaweicloud.com>,
"Li Huafei" <lihuafei1@huawei.com>,
"Thorsten Blum" <thorsten.blum@linux.dev>,
"Yicong Yang" <yangyicong@hisilicon.com>,
linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org,
kexec@lists.infradead.org, linux-hardening@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 8/9] panic/printk: replace other_cpu_in_panic() with panic_on_other_cpu()
Date: Mon, 25 Aug 2025 10:29:36 +0800 [thread overview]
Message-ID: <20250825022947.1596226-9-wangjinchao600@gmail.com> (raw)
In-Reply-To: <20250825022947.1596226-1-wangjinchao600@gmail.com>
The helper other_cpu_in_panic() duplicated logic already provided by
panic_on_other_cpu().
Remove other_cpu_in_panic() and update all users to call
panic_on_other_cpu() instead.
This removes redundant code and makes panic handling consistent.
Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
---
kernel/printk/internal.h | 1 -
kernel/printk/nbcon.c | 8 ++++----
kernel/printk/printk.c | 19 ++++---------------
3 files changed, 8 insertions(+), 20 deletions(-)
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h
index ef282001f200..f72bbfa266d6 100644
--- a/kernel/printk/internal.h
+++ b/kernel/printk/internal.h
@@ -332,7 +332,6 @@ struct printk_message {
unsigned long dropped;
};
-bool other_cpu_in_panic(void);
bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
bool is_extended, bool may_supress);
diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
index c6d1a4a747e9..171480135830 100644
--- a/kernel/printk/nbcon.c
+++ b/kernel/printk/nbcon.c
@@ -255,7 +255,7 @@ static int nbcon_context_try_acquire_direct(struct nbcon_context *ctxt,
* opportunity to perform any necessary cleanup if they were
* interrupted by the panic CPU while printing.
*/
- if (other_cpu_in_panic() &&
+ if (panic_on_other_cpu() &&
(!is_reacquire || cur->unsafe_takeover)) {
return -EPERM;
}
@@ -310,7 +310,7 @@ static bool nbcon_waiter_matches(struct nbcon_state *cur, int expected_prio)
* Event #2 implies the new context is PANIC.
* Event #3 occurs when panic() has flushed the console.
* Event #4 occurs when a non-panic CPU reacquires.
- * Event #5 is not possible due to the other_cpu_in_panic() check
+ * Event #5 is not possible due to the panic_on_other_cpu() check
* in nbcon_context_try_acquire_handover().
*/
@@ -349,7 +349,7 @@ static int nbcon_context_try_acquire_requested(struct nbcon_context *ctxt,
struct nbcon_state new;
/* Note that the caller must still remove the request! */
- if (other_cpu_in_panic())
+ if (panic_on_other_cpu())
return -EPERM;
/*
@@ -447,7 +447,7 @@ static int nbcon_context_try_acquire_handover(struct nbcon_context *ctxt,
* nbcon_waiter_matches(). In particular, the assumption that
* lower priorities are ignored during panic.
*/
- if (other_cpu_in_panic())
+ if (panic_on_other_cpu())
return -EPERM;
/* Handover is not possible on the same CPU. */
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index faa8b1f0585b..236f03937107 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -346,17 +346,6 @@ static void __up_console_sem(unsigned long ip)
}
#define up_console_sem() __up_console_sem(_RET_IP_)
-/*
- * Return true if a panic is in progress on a remote CPU.
- *
- * On true, the local CPU should immediately release any printing resources
- * that may be needed by the panic CPU.
- */
-bool other_cpu_in_panic(void)
-{
- return (panic_in_progress() && !panic_on_this_cpu());
-}
-
/*
* This is used for debugging the mess that is the VT code by
* keeping track if we have the console semaphore held. It's
@@ -2391,7 +2380,7 @@ asmlinkage int vprintk_emit(int facility, int level,
* non-panic CPUs are generating any messages, they will be
* silently dropped.
*/
- if (other_cpu_in_panic() &&
+ if (panic_on_other_cpu() &&
!debug_non_panic_cpus &&
!panic_triggering_all_cpu_backtrace)
return 0;
@@ -2827,7 +2816,7 @@ void console_lock(void)
might_sleep();
/* On panic, the console_lock must be left to the panic cpu. */
- while (other_cpu_in_panic())
+ while (panic_on_other_cpu())
msleep(1000);
down_console_sem();
@@ -2847,7 +2836,7 @@ EXPORT_SYMBOL(console_lock);
int console_trylock(void)
{
/* On panic, the console_lock must be left to the panic cpu. */
- if (other_cpu_in_panic())
+ if (panic_on_other_cpu())
return 0;
if (down_trylock_console_sem())
return 0;
@@ -3227,7 +3216,7 @@ static bool console_flush_all(bool do_cond_resched, u64 *next_seq, bool *handove
any_progress = true;
/* Allow panic_cpu to take over the consoles safely. */
- if (other_cpu_in_panic())
+ if (panic_on_other_cpu())
goto abandon;
if (do_cond_resched)
--
2.43.0
next prev parent reply other threads:[~2025-08-25 6:55 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-25 2:29 [PATCH v2 0/9] panic: introduce panic status function family Jinchao Wang
2025-08-25 2:29 ` [PATCH v2 1/9] panic: Introduce helper functions for panic state Jinchao Wang
2025-08-25 2:29 ` [PATCH v2 2/9] fbdev: Use panic_in_progress() helper Jinchao Wang
2025-08-25 2:29 ` [PATCH v2 3/9] crash_core: use panic_try_start() in crash_kexec() Jinchao Wang
2025-08-29 2:30 ` Qianqiang Liu
2025-08-29 4:39 ` Jinchao Wang
2025-08-25 2:29 ` [PATCH v2 4/9] panic: use panic_try_start() in nmi_panic() Jinchao Wang
2025-08-25 2:29 ` [PATCH v2 5/9] panic: use panic_try_start() in vpanic() Jinchao Wang
2025-08-25 2:29 ` [PATCH v2 6/9] printk/nbcon: use panic_on_this_cpu() helper Jinchao Wang
2025-08-25 2:29 ` [PATCH v2 7/9] panic/printk: replace this_cpu_in_panic() with panic_on_this_cpu() Jinchao Wang
2025-08-25 2:29 ` Jinchao Wang [this message]
2025-08-25 2:29 ` [PATCH v2 9/9] watchdog: skip checks when panic is in progress Jinchao Wang
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