From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2B826178890; Fri, 29 Mar 2024 12:40:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711716026; cv=none; b=qjiMNCnmAJSmFzbsG12ar+NfqeLe64xVN4LECk271p65QYdw3W3YgfuQonGv7VoZ6NPV8lcwI2mWzf3bE6pJAcj7XVE2b5Gd2x4RLvgOjWBP0o+30MS7LAts7N0IoFT+kffSA7Lvjl/d9XjAMspSn2p/REDhdB7EhcXJE2cPHNU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711716026; c=relaxed/simple; bh=WBxuzQAL7Uk/oH50pW4tkZDR4/xjBoDCxy6UmwLkmH8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CAxYIyQ1oEhKeNnG8+vEMrYGwocaoHG8XB7aTEd2K1gn/GoeyvRqfHAzLlr2Q35IplENw1cytl8snbwYy7cqjguwZL5n/4RQbiTgD7QgggOl86exCDztgonU6X1kO8g2ytS2dnCc/qAs5Wq9ijteU24UTevmY9qc0AtAGUI1+SQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AwmLFsjS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AwmLFsjS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AA3A7C43390; Fri, 29 Mar 2024 12:40:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711716026; bh=WBxuzQAL7Uk/oH50pW4tkZDR4/xjBoDCxy6UmwLkmH8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AwmLFsjSEurH2/xTUh39aRikZ4o/+Xl2mQfTUYFMUNRqd1gPOIovzvSTlzAFJ92Dw SO5KwGos8PmdSwd0bgMXY10NoM+Oh/uAm507aeLBhcUsw9mk4UoNO8yBHHtzWmjS+w u3E46R3vKttIVMCkAHE9We+i5lXFLXXDOuTU7B46efMdWAeOQ7AnzAh/d3+ILIpZT7 JH/UIGa+x5/HTMJpPhWv4rLRzdkQdk287JfbOk6fp7uG02tnWgAgKW5E4O5C96jXIw pSSwufKvLfD6VRTI+JxFU/SKlPmf6bQ3b/Jrvm6LBQ+OULoNwRx2Mrirw5iARCAZ/A gemv8SuiYrV4Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: John Ogness , Petr Mladek , Sasha Levin , akpm@linux-foundation.org, peterz@infradead.org, jpoimboe@kernel.org, wangkefeng.wang@huawei.com, ubizjak@gmail.com, feng.tang@intel.com, bhe@redhat.com, arnd@arndb.de Subject: [PATCH AUTOSEL 6.8 22/98] panic: Flush kernel log buffer at the end Date: Fri, 29 Mar 2024 08:36:53 -0400 Message-ID: <20240329123919.3087149-22-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240329123919.3087149-1-sashal@kernel.org> References: <20240329123919.3087149-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.8.2 Content-Transfer-Encoding: 8bit From: John Ogness [ Upstream commit d988d9a9b9d180bfd5c1d353b3b176cb90d6861b ] If the kernel crashes in a context where printk() calls always defer printing (such as in NMI or inside a printk_safe section) then the final panic messages will be deferred to irq_work. But if irq_work is not available, the messages will not get printed unless explicitly flushed. The result is that the final "end Kernel panic" banner does not get printed. Add one final flush after the last printk() call to make sure the final panic messages make it out as well. Signed-off-by: John Ogness Reviewed-by: Petr Mladek Link: https://lore.kernel.org/r/20240207134103.1357162-14-john.ogness@linutronix.de Signed-off-by: Petr Mladek Signed-off-by: Sasha Levin --- kernel/panic.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/panic.c b/kernel/panic.c index 2807639aab51d..f22d8f33ea147 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -446,6 +446,14 @@ void panic(const char *fmt, ...) /* Do not scroll important messages printed above */ suppress_printk = 1; + + /* + * The final messages may not have been printed if in a context that + * defers printing (such as NMI) and irq_work is not available. + * Explicitly flush the kernel log buffer one last time. + */ + console_flush_on_panic(CONSOLE_FLUSH_PENDING); + local_irq_enable(); for (i = 0; ; i += PANIC_TIMER_STEP) { touch_softlockup_watchdog(); -- 2.43.0