From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ms.lwn.net (ms.lwn.net [45.79.88.28]) (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 9283A2773F7; Tue, 14 Oct 2025 14:55:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.79.88.28 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760453733; cv=none; b=A6ztHeq8Uesnc/Ea7HPd8NvqMaNwXeyORxFljyAvAvua7XKmP83M/OZXP0V76ZGVqVJ9VrvjiFtkqkL9Y371qrRNsAjMPFW9Q1mNG0mmJoQK0kBEqM4ugk09VRTwfFfybAqluESv8xuSIreVBcm/6udXHfX3oR67CQaot445JeI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760453733; c=relaxed/simple; bh=oJjRXMYAtYfstJ1Qe7kiRTx+N9SnMeZBjZHi92bWT2w=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=s3p5RR2RomgdnJJD72iRcsiqYxWaxvPy0Vbhg8KTn+1fGDKeHwGbyBpV+lqKYcgsvKOr4alkHmPDsrNi5IdYQMHLaqJZDOhs7wV68hdG87G2UtLsharb9iTdh57lrVvYfPom7n19MrzFU3INsocqbma7hSNJ3/DjU5bHhgrxdJ4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net; spf=pass smtp.mailfrom=lwn.net; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b=U0wFU7Gc; arc=none smtp.client-ip=45.79.88.28 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lwn.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b="U0wFU7Gc" DKIM-Filter: OpenDKIM Filter v2.11.0 ms.lwn.net 8807540B1E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lwn.net; s=20201203; t=1760453730; bh=2NhCZaS0JRHpCMdnPaecLqGEPTG+OSiP6xNnzI2UmlA=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=U0wFU7Gc5aXlrvnGS2+/0yPHl5lknOISny431eW8j9/31oHjg0V8CqS0veDMbj3Pq zNXqBUbFkT4E2ZHSz905Ed12lmOfNnqTovYrnFJ9IT4ZAgC638UPzc3+NPT/uyd/e2 PaqT9D/NKZ+ivU/6gQqcfpSTI8am+lGw03CPbe2aGYUO5vShSnGBRlz38uG06FGaoX PXeiObeHWk5lWK6xyT9xiSodkGzAKghCBhHKeicqVVzd04W8tGlWyyw8+i4YNA1X+A EM2uuZFuEp72eJPB3hOmOZybWELdSZ2zeyFS72/qteF4Em6A2ViztDKvVdUQ1wBiRG OsWb0/j+s9rYQ== Received: from localhost (unknown [IPv6:2601:280:4600:2da9::1fe]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ms.lwn.net (Postfix) with ESMTPSA id 8807540B1E; Tue, 14 Oct 2025 14:55:30 +0000 (UTC) From: Jonathan Corbet To: Bagas Sanjaya , Linux Kernel Mailing List , Linux Documentation , Linux Serial Cc: Cengiz Can , Bagas Sanjaya , Tomas Mudrunka , Jiri Slaby , Greg Kroah-Hartman , Anselm =?utf-8?Q?Sch=C3=BCler?= Subject: Re: [PATCH] Documentation: sysrq: Remove contradicting sentence on extra /proc/sysrq-trigger characters In-Reply-To: <20251008112409.33622-1-bagasdotme@gmail.com> References: <20251008112409.33622-1-bagasdotme@gmail.com> Date: Tue, 14 Oct 2025 08:55:29 -0600 Message-ID: <87wm4xbkim.fsf@trenco.lwn.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Bagas Sanjaya writes: > /proc/sysrq-trigger documentation states that only first character is > processed and the rest is ignored, yet it is not recommended to write > any extra characters to it. The latter statement is contradictive as > these characters are also ignored as implied by preceding sentence. > > Remove it. > > Link: https://lore.kernel.org/lkml/7ca05672-dc20-413f-a923-f77ce0a9d307@anselmschueler.com/ > Signed-off-by: Bagas Sanjaya > --- > Documentation/admin-guide/sysrq.rst | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/Documentation/admin-guide/sysrq.rst b/Documentation/admin-guide/sysrq.rst > index 9c7aa817adc72d..63ff415ce85d66 100644 > --- a/Documentation/admin-guide/sysrq.rst > +++ b/Documentation/admin-guide/sysrq.rst > @@ -77,9 +77,7 @@ On other > On all > Write a single character to /proc/sysrq-trigger. > Only the first character is processed, the rest of the string is > - ignored. However, it is not recommended to write any extra characters > - as the behavior is undefined and might change in the future versions. > - E.g.:: > + ignored. E.g.:: I'm not sure this is right - there is a warning here that additional characters may acquire a meaning in the future, so one should not develop the habit of writing them now. After all these years, I think the chances of fundamental sysrq changes are pretty small, but I still don't see why we would take the warning out? jon