From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bregans-1.gladserv.net (bregans-1.gladserv.net [185.128.211.58]) (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 57B801C3C08 for ; Sat, 23 Aug 2025 13:59:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.128.211.58 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755957601; cv=none; b=u/oZPpyYtittV2S47VSN16pTZ5blcTV7sSR8indJP++53tBYsNTK7TVS764V2MT53vPt+Hsr3fiwl5kmEYRuG0SPr7rfWwO9oThFzlj1cKbPsF3AK2MgKlGv0PS+l5whRRqNzg3Ev1Fq7hE98PEl3nxg4finOi3w/pOMVSE1kOw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755957601; c=relaxed/simple; bh=97I+DQOaL6uOug3mpsSAXsQpGUefzLWk+4vhU28mdjc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Tri7c5rGJxCtOpcpIrc7mQSrILKmYxCsSfEwJIBvXvB5j+SGTecvQiYi5ah3wUqS81iryogJ8MPKALbkGYyJSN2r5zucTENih072ZZeh5F6vc0ZAW9a9or58i/yqVSl4V6Am7zFkB993PjoPCPHQkL11YdD+9aCrHO5YAECqWPc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=librecast.net; spf=pass smtp.mailfrom=librecast.net; arc=none smtp.client-ip=185.128.211.58 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=librecast.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=librecast.net Date: Sat, 23 Aug 2025 13:59:54 +0000 From: Brett A C Sheffield To: Greg KH Cc: stable@vger.kernel.org Subject: Re: Backporting Selftests to Stable Kernels? Message-ID: References: <2025082352-hefty-humorous-700d@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2025082352-hefty-humorous-700d@gregkh> On 2025-08-23 15:51, Greg KH wrote: > On Sat, Aug 23, 2025 at 03:05:46PM +0200, Brett Sheffield wrote: > > Dear Stable Maintainers, > > > > When a bugfix is backported to stable kernels, should we be backporting the > > associated selftest(s)? > > If you want to, sure! > > > eg. > > > > 9e30ecf23b1b ("net: ipv4: fix incorrect MTU in broadcast routes") > > was backported to stable, but the selftest was not: > > 5777d1871bf6 ("selftests: net: add test for variable PMTU in broadcast routes") > > > > Does stable policy say whether it should be? > > It's up to the subsystem/maintainer/developer/whomever if they wish to > do that or not. Some subsystems want to do this, others don't, others > don't care. > > > It does not fix a bug, per se, but it does enable those of us running stable > > kernel tests to more thoroughly test stable RCs. > > Note that you should always be running the latest selftests for older > kernels, and I think that's what many of the CI systems are already > doing, so maybe that's why you don't notice stuff like this? > > That's the only "rule" we have, all new selftests need to work properly > for older kernels. > > > Should mainline authors be encouraged to mark related tests for backporting? > > Again, it's up to them if they want to or not. I will point out mptcp > as one subsystem that does mark selftests to backport, and provides > backports for when they do not apply correctly. > > hope this helps, Thanks Greg. It does. Brett