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 149D913AD0C; Thu, 11 Apr 2024 10:04:07 +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=1712829847; cv=none; b=LHJ/YpPEpHJkIV549qHNcIJoFlWCTZoYTBdJZ2A66QT2hauBgbMZC3gWg21YlNN1B5AFKkj5IGBGmKwaKAzr+x/c23ozWiaM2IKKFZKq9NVivDRS6qlkYOaFQsXPXNhOKNn8ZOO2Vjk86dIVD8LwKfisWgvK0pJklE2LaCkR+gI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712829847; c=relaxed/simple; bh=Lf3Ec4GdDwyTtG+/K8uNbpuSbZ9keSRNSvGORemGxkw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UeM70SKePS34Avq6PqqV//cuyJdYp+qEvQ1ls8WrHWQ37lyyEVY/hE4hXlWYY38YQonokHfrwmXs53r6w42NmaTV2fARfBiClGZSleR6d/S89Lvga4dzU1LKkzG3Bm8Mcja6sQcZSZ5d4ALe96XaZ5VXdjiZ/jUlo1ti9kpUpo4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CENSAMwK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="CENSAMwK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 616A7C433F1; Thu, 11 Apr 2024 10:04:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712829847; bh=Lf3Ec4GdDwyTtG+/K8uNbpuSbZ9keSRNSvGORemGxkw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CENSAMwKld4z/19iSQvOmG64DNrtvO/ku2z6EFghZXXKDYCcezwyzVO+Ri/i8e6j0 On1gwIctTEH92DgnClUISOZ25UvSjXl5B3py5i79lY00oHlRvDjqz4pgb54yyAdKsq O+4PbZww3fgLfWwPoVoWxtQLC0i+IRGdVfa1SrQA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mukesh Ojha , John Ogness , Petr Mladek , Sasha Levin Subject: [PATCH 4.19 087/175] printk: Update @console_may_schedule in console_trylock_spinning() Date: Thu, 11 Apr 2024 11:55:10 +0200 Message-ID: <20240411095422.181466343@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095419.532012976@linuxfoundation.org> References: <20240411095419.532012976@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: John Ogness [ Upstream commit 8076972468584d4a21dab9aa50e388b3ea9ad8c7 ] console_trylock_spinning() may takeover the console lock from a schedulable context. Update @console_may_schedule to make sure it reflects a trylock acquire. Reported-by: Mukesh Ojha Closes: https://lore.kernel.org/lkml/20240222090538.23017-1-quic_mojha@quicinc.com Fixes: dbdda842fe96 ("printk: Add console owner and waiter logic to load balance console writes") Signed-off-by: John Ogness Reviewed-by: Mukesh Ojha Reviewed-by: Petr Mladek Link: https://lore.kernel.org/r/875xybmo2z.fsf@jogness.linutronix.de Signed-off-by: Petr Mladek Signed-off-by: Sasha Levin --- kernel/printk/printk.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 2ba16c426ba5d..66c78dfd17925 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1732,6 +1732,12 @@ static int console_trylock_spinning(void) */ mutex_acquire(&console_lock_dep_map, 0, 1, _THIS_IP_); + /* + * Update @console_may_schedule for trylock because the previous + * owner may have been schedulable. + */ + console_may_schedule = 0; + return 1; } -- 2.43.0