From nobody Mon Dec 1 22:03:24 2025 Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 69FF030ACF6 for ; Thu, 27 Nov 2025 19:43:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764272640; cv=none; b=m50ItyjufpxqGjMOMXiJc5jevAD0plpNFCpelmWhrQC7dmhF/xaOx6Jvqc+Sgp8HqJlRd+XdYSPwrDiPvKcqhA+SUKwSBcwbNNEgmNxDfvq0ZZXM1lsSK6QIRnHOoFelz28bZMfLq2/ZIxjOF21LD+j8OYVdh6g967D+/9lhfnM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764272640; c=relaxed/simple; bh=kFggCPoWkga9O532Ajl+K+dSe8kAx3nxGHgpearLRxs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TYKw/z52rp2zHVWTupknbKGAR8gmVR9h1SYxl1mbm8S2ZDAaTrm8TWWmhXXeG5ZhK0Fb2flNXo25R2ldPan7MMQL5W3jrRGBStoO1uNKcfDf+sAI8Pu5+X5QwX/Xj5lqgvyxYJnIeAeTZ2qmzqHP0OibLvdwrNcr7Z+j3YvgoVw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=chrisdown.name; spf=pass smtp.mailfrom=chrisdown.name; dkim=pass (1024-bit key) header.d=chrisdown.name header.i=@chrisdown.name header.b=mWfxacxv; arc=none smtp.client-ip=209.85.214.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=chrisdown.name Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chrisdown.name Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chrisdown.name header.i=@chrisdown.name header.b="mWfxacxv" Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-298456bb53aso13564595ad.0 for ; Thu, 27 Nov 2025 11:43:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chrisdown.name; s=google; t=1764272638; x=1764877438; darn=vger.kernel.org; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=hef6GIbGSP1iHi47y6Ts9uKlOqlwoUNbqs7Mh1c39OA=; b=mWfxacxvPM/p+RdRdgZWsc8CpyAMHTs3M0/rXUzo0qel0fPCMqj4bJTt0sySkgNiRu tNjyeRT7iB1Gx/SU7iADT6jQPTnlUw1UEvMSMlZ3zMkz/NeWlKx320nuaBHnmratyjGL ARwdFxIkF49Dt6VT7QpOfQHxx38eC20CwNp6M= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764272638; x=1764877438; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=hef6GIbGSP1iHi47y6Ts9uKlOqlwoUNbqs7Mh1c39OA=; b=LcmmXLR7pNZvXOX5S1szXhcZLwc82JhGdm9Lxtq6tMujjmtm9C69A86wHPGio1S88Q UakidhQuagrP+YlT2lYHQtsfgKLPN7wdk/iwpGlY+fEEDyTVdqvMnwg4e37ZZT263qKt JYvuaqXbMifBr5WGwbPlZFruuuL68sorzEsgBuXmhXQpQGZNdwY8BdGZ7i29HLOdp9HR Xflv/yS8jn5kQWJoNGr7JXr6uuTgfv8nnFOcTMLs+N/3+UXc6QjHQkMTu0JTkcaD8Lv1 ZkrVq/RB9ddqEcJtPej+vEweUTkn6G0Y5JeNMaxiPxbUdMdMbNIznmW8tRTzuq5+scrl hAPg== X-Gm-Message-State: AOJu0YwyeOopl9T4Tpnohz0SB6yBBbMzBizrAI9Pw3cnWyN9N/3je1Yx Z/mTvlYHut/fQTbO+duVUI4sSJshJPIHV43noGCOknCug6AHPhJ5sdJHnsxNJrkN9d8= X-Gm-Gg: ASbGnctDvMaAowTII5bRaQPVCE59YqQrgctqhNuuFRMOno8FAetruJYd6aOWpkvFU9/ sIn14n9BsX2A4II1pJ+MUKrGtwsocGZaK5ljh0Es+joqK+Q39MSqCCqMNPpyElTFuziKZrgE71u bVBLUtUtAS0la7WuFPq8iTkp49vcnN1DDMi4/dVHm2gROnbWFAOE1ybzNMyS9kTr4c2uSJ/TohF rQNWw3wJu6oucgtx0FTzoGJ1vHCa24WGQ+seAHLGgGaCW0ZVN4g20uqKc9HJG9A5UWjNvMC7gn7 M36jRg3f1Xg5z2kzXAwkTjbOCeULe5yefOWGq53h1+bA7ZwDT+oTRXtB9rAukCXReU8LueNUPBg SZgBTF6D8UKKYVZC7f/9E9GZEwOjiT/JqcpLrJTrc7YVz3cSxVckZwp1hM1469UygQtJntUaWoj vZWheQZJ17 X-Google-Smtp-Source: AGHT+IG3x/SehW2TWe4iBxKpSW0+ZAKL4bIMLNBZyUTR0cB02gMFwS2Ijfu04lj5LYyeLc7GZ2ZbGg== X-Received: by 2002:a17:903:11c7:b0:24b:24dc:91a7 with SMTP id d9443c01a7336-29b6c6a8cf1mr273854495ad.45.1764272637677; Thu, 27 Nov 2025 11:43:57 -0800 (PST) Received: from localhost ([116.86.198.140]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-29bceb27691sm24749365ad.64.2025.11.27.11.43.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Nov 2025 11:43:57 -0800 (PST) Date: Fri, 28 Nov 2025 03:43:54 +0800 From: Chris Down To: Petr Mladek Cc: linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Sergey Senozhatsky , Steven Rostedt , John Ogness , Geert Uytterhoeven , Tony Lindgren , kernel-team@fb.com Subject: [PATCH v8 12/21] printk: Ensure sysrq output bypasses per-console filtering Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.15 (2b349c5e) (2025-10-02) Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" During sysrq handling, per-console loglevels are temporarily disabled to ensure all requisite messages are printed to the console. This is necessary because sysrq is often used in dire circumstances where access to /sys/class/console may not be trivially possible, and all diagnostic output needs to reach the operator regardless of per-console filtering. The implementation saves and restores the ignore_per_console_loglevel flag around the sysrq handler, similar to how suppress_printk is already handled. Reviewed-by: Petr Mladek Signed-off-by: Chris Down --- drivers/tty/sysrq.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index 97f8a9a52285..1d5ae9997e79 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -51,6 +51,7 @@ #include #include #include +#include =20 #include #include @@ -583,12 +584,16 @@ static void __sysrq_put_key_op(u8 key, const struct s= ysrq_key_op *op_p) void __handle_sysrq(u8 key, bool check_mask) { const struct sysrq_key_op *op_p; + bool orig_ignore_per_console_loglevel; int orig_suppress_printk; int i; =20 orig_suppress_printk =3D suppress_printk; suppress_printk =3D 0; =20 + orig_ignore_per_console_loglevel =3D ignore_per_console_loglevel; + ignore_per_console_loglevel =3D true; + rcu_sysrq_start(); rcu_read_lock(); /* @@ -634,6 +639,7 @@ void __handle_sysrq(u8 key, bool check_mask) rcu_read_unlock(); rcu_sysrq_end(); =20 + ignore_per_console_loglevel =3D orig_ignore_per_console_loglevel; suppress_printk =3D orig_suppress_printk; } =20 --=20 2.51.2