From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>, takakura@valinux.co.jp
Cc: rostedt@goodmis.org, senozhatsky@chromium.org,
akpm@linux-foundation.org, bhe@redhat.com, lukas@wunner.de,
wangkefeng.wang@huawei.com, ubizjak@gmail.com,
feng.tang@intel.com, j.granados@samsung.com,
stephen.s.brennan@oracle.com, linux-kernel@vger.kernel.org,
nishimura@valinux.co.jp, taka@valinux.co.jp
Subject: Re: [PATCH v2 1/2] Handle flushing of CPU backtraces during panic
Date: Mon, 05 Aug 2024 16:14:06 +0206 [thread overview]
Message-ID: <87r0b32hbt.fsf@jogness.linutronix.de> (raw)
In-Reply-To: <ZrDYfU6SVrR2Hj02@pathway.suse.cz>
On 2024-08-05, Petr Mladek <pmladek@suse.com> wrote:
>> diff --git a/kernel/panic.c b/kernel/panic.c
>> index 7e2070925..f94923a63 100644
>> --- a/kernel/panic.c
>> +++ b/kernel/panic.c
>> @@ -252,8 +252,10 @@ void check_panic_on_warn(const char *origin)
>> */
>> static void panic_other_cpus_shutdown(bool crash_kexec)
>> {
>> - if (panic_print & PANIC_PRINT_ALL_CPU_BT)
>> + if (panic_print & PANIC_PRINT_ALL_CPU_BT) {
>> trigger_all_cpu_backtrace();
>> + console_flush_on_panic(CONSOLE_FLUSH_PENDING);
>
> Hmm, this is too dangerous.
>
> console_flush_on_panic() is supposed to be called at the end on
> panic() as the final desperate attempt to flush consoles.
Thanks for catching this. I keep forgetting that
console_flush_on_panic() is the legacy variant of
nbcon_atomic_flush_unsafe(), but is called much earlier.
John
next prev parent reply other threads:[~2024-08-05 14:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-03 8:04 [PATCH v2 0/2] printk: CPU backtrace not printing on panic takakura
2024-08-03 8:12 ` [PATCH v2 1/2] Handle flushing of CPU backtraces during panic takakura
2024-08-05 13:49 ` Petr Mladek
2024-08-05 14:08 ` John Ogness [this message]
2024-08-07 8:56 ` takakura
2024-08-05 14:04 ` John Ogness
2024-08-07 8:59 ` takakura
2024-08-03 8:16 ` [PATCH v2 2/2] Allow cpu backtraces to be written into ringbuffer " takakura
2024-08-05 13:51 ` Petr Mladek
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