From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8277C43461 for ; Fri, 4 Sep 2020 11:55:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9460214F1 for ; Fri, 4 Sep 2020 11:55:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599220546; bh=3gjh72ssf9Q4cLyUZJiBs6BnZ4iUD7PvuTcSLsrMwQk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=gRkY1T3rw5leqNCh5yQLCygRcD3fCO96NKz23E8wt9NnpPESIE7VhYy+JOP8tpWaq v04beq4stSzKZzWbB8lo8RQ3Gt7ZHl8jkxeg+Q2y97OsxmaIb7D9Esm9GCit1dskZp N76T7wbJuMnU8LND2UXuOK420bnbSZRd40tYXZ+M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730021AbgIDLzp (ORCPT ); Fri, 4 Sep 2020 07:55:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:58962 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729897AbgIDLzj (ORCPT ); Fri, 4 Sep 2020 07:55:39 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AA13E214F1; Fri, 4 Sep 2020 11:55:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599220538; bh=3gjh72ssf9Q4cLyUZJiBs6BnZ4iUD7PvuTcSLsrMwQk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=X251CJuI/Ywhpc5U5mJzTiW8MI5Lom7mP/1kes/9EHNa5BrvU6C9iZY+0B8WSTJwT 7wYGHJHR0QJHbjLPsTHnLnhIHZllV1kZ2TrHE2al4VL/7ubptyXuu0hWE+8NhTwaAj 8Hl9zy/6MzMqjPFzYE7XSQE9H9JEnDauJ1fMK4xw= Date: Fri, 4 Sep 2020 13:55:59 +0200 From: Greg KH To: Bodo Stroesser Cc: "Martin K. Petersen" , target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, Mike Christie , stable@vger.kernel.org Subject: Re: [PATCH] scsi: target: tcmu: fix size in calls to tcmu_flush_dcache_range Message-ID: <20200904115559.GC2964473@kroah.com> References: <20200528193108.9085-1-bstroesser@ts.fujitsu.com> <159114947916.26776.943125808891892721.b4-ty@oracle.com> <79f7119f-fda7-64cc-b617-d49a23f2e628@ts.fujitsu.com> <28862cd1-e7f2-d161-1bab-4d2ff73cf6a1@ts.fujitsu.com> <20200901140212.GE397411@kroah.com> <8ced4335-dcae-96c8-7c14-3eeb5c97324b@ts.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8ced4335-dcae-96c8-7c14-3eeb5c97324b@ts.fujitsu.com> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On Tue, Sep 01, 2020 at 05:58:29PM +0200, Bodo Stroesser wrote: > On 2020-09-01 16:02, Greg KH wrote: > > On Fri, Aug 28, 2020 at 12:03:38PM +0200, Bodo Stroesser wrote: > >> Hi, > >> I'm adding stable@vger.kernel.org > >> > >> Once again, this time really adding stable. > >> > >> On 2020-06-03 04:31, Martin K. Petersen wrote: > >>> On Thu, 28 May 2020 21:31:08 +0200, Bodo Stroesser wrote: > >>> > >>>> 1) If remaining ring space before the end of the ring is > >>>> smaller then the next cmd to write, tcmu writes a padding > >>>> entry which fills the remaining space at the end of the > >>>> ring. > >>>> Then tcmu calls tcmu_flush_dcache_range() with the size > >>>> of struct tcmu_cmd_entry as data length to flush. > >>>> If the space filled by the padding was smaller then > >>>> tcmu_cmd_entry, tcmu_flush_dcache_range() is called for > >>>> an address range reaching behind the end of the vmalloc'ed > >>>> ring. > >>>> tcmu_flush_dcache_range() in a loop calls > >>>> flush_dcache_page(virt_to_page(start)); > >>>> for every page being part of the range. On x86 the line is > >>>> optimized out by the compiler, as flush_dcache_page() is > >>>> empty on x86. > >>>> But I assume the above can cause trouble on other > >>>> architectures that really have a flush_dcache_page(). > >>>> For paddings only the header part of an entry is relevant > >>>> Due to alignment rules the header always fits in the > >>>> remaining space, if padding is needed. > >>>> So tcmu_flush_dcache_range() can safely be called with > >>>> sizeof(entry->hdr) as the length here. > >>>> > >>>> [...] > >>> > >>> Applied to 5.8/scsi-queue, thanks! > >>> > >>> [1/1] scsi: target: tcmu: Fix size in calls to tcmu_flush_dcache_range > >>> https://git.kernel.org/mkp/scsi/c/8c4e0f212398 > >>> > >> > >> The full commit of this patch is: > >> 8c4e0f212398cdd1eb4310a5981d06a723cdd24f > >> > >> This patch is the first of four patches that are necessary to run tcmu > >> on ARM without crash. For details please see > >> https://bugzilla.kernel.org/show_bug.cgi?id=208045 > >> Upsteam commits of patches 2,3, and 4 are: > >> 2: 3c58f737231e "scsi: target: tcmu: Optimize use of flush_dcache_page" > >> 3: 3145550a7f8b "scsi: target: tcmu: Fix crash in tcmu_flush_dcache_range > >> on ARM" > >> 4: 5a0c256d96f0 "scsi: target: tcmu: Fix crash on ARM during cmd > >> completion" > >> > >> Since patches 3 and 4 already were accepted for 5.8, 5.4, and 4.19, and > >> I sent a request to add patch 2 about 1 hour ago, please consider adding > >> this patch to 5.4 and 4.19, because without it tcmu on ARM will still > >> crash. > > > > I don't see such a request, and am confused now. > > > > What exact commits do you want backported, and to what trees? > > > > thanks, > > > > greg k-h > > > > Sorry for the confusion. > > The subject of the request I mentioned is > "Re: [PATCH v2 0/2] scsi: target: tcmu: fix crashes on ARM" > because it is for the first patch of a small series of two. > > Please backport to kernels 4.19 and 5.4 (it is part of 5.8 from beginning): > 8c4e0f212398 "scsi: target: tcmu: fix size in calls to tcmu_flush_dcache_range" > > Please backport to kernels 4.19, 5.4 and 5.8: > 3c58f737231e "scsi: target: tcmu: Optimize use of flush_dcache_page" > > Backporting to 4.14 or earlier AFAICS would need more work, especially testing. > I don't think that its worth it. Thanks, both now queued up. greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Date: Fri, 04 Sep 2020 11:55:59 +0000 Subject: Re: [PATCH] scsi: target: tcmu: fix size in calls to tcmu_flush_dcache_range Message-Id: <20200904115559.GC2964473@kroah.com> List-Id: References: <20200528193108.9085-1-bstroesser@ts.fujitsu.com> <159114947916.26776.943125808891892721.b4-ty@oracle.com> <79f7119f-fda7-64cc-b617-d49a23f2e628@ts.fujitsu.com> <28862cd1-e7f2-d161-1bab-4d2ff73cf6a1@ts.fujitsu.com> <20200901140212.GE397411@kroah.com> <8ced4335-dcae-96c8-7c14-3eeb5c97324b@ts.fujitsu.com> In-Reply-To: <8ced4335-dcae-96c8-7c14-3eeb5c97324b@ts.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Bodo Stroesser Cc: "Martin K. Petersen" , target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, Mike Christie , stable@vger.kernel.org On Tue, Sep 01, 2020 at 05:58:29PM +0200, Bodo Stroesser wrote: > On 2020-09-01 16:02, Greg KH wrote: > > On Fri, Aug 28, 2020 at 12:03:38PM +0200, Bodo Stroesser wrote: > >> Hi, > >> I'm adding stable@vger.kernel.org > >> > >> Once again, this time really adding stable. > >> > >> On 2020-06-03 04:31, Martin K. Petersen wrote: > >>> On Thu, 28 May 2020 21:31:08 +0200, Bodo Stroesser wrote: > >>> > >>>> 1) If remaining ring space before the end of the ring is > >>>> smaller then the next cmd to write, tcmu writes a padding > >>>> entry which fills the remaining space at the end of the > >>>> ring. > >>>> Then tcmu calls tcmu_flush_dcache_range() with the size > >>>> of struct tcmu_cmd_entry as data length to flush. > >>>> If the space filled by the padding was smaller then > >>>> tcmu_cmd_entry, tcmu_flush_dcache_range() is called for > >>>> an address range reaching behind the end of the vmalloc'ed > >>>> ring. > >>>> tcmu_flush_dcache_range() in a loop calls > >>>> flush_dcache_page(virt_to_page(start)); > >>>> for every page being part of the range. On x86 the line is > >>>> optimized out by the compiler, as flush_dcache_page() is > >>>> empty on x86. > >>>> But I assume the above can cause trouble on other > >>>> architectures that really have a flush_dcache_page(). > >>>> For paddings only the header part of an entry is relevant > >>>> Due to alignment rules the header always fits in the > >>>> remaining space, if padding is needed. > >>>> So tcmu_flush_dcache_range() can safely be called with > >>>> sizeof(entry->hdr) as the length here. > >>>> > >>>> [...] > >>> > >>> Applied to 5.8/scsi-queue, thanks! > >>> > >>> [1/1] scsi: target: tcmu: Fix size in calls to tcmu_flush_dcache_range > >>> https://git.kernel.org/mkp/scsi/c/8c4e0f212398 > >>> > >> > >> The full commit of this patch is: > >> 8c4e0f212398cdd1eb4310a5981d06a723cdd24f > >> > >> This patch is the first of four patches that are necessary to run tcmu > >> on ARM without crash. For details please see > >> https://bugzilla.kernel.org/show_bug.cgi?id 8045 > >> Upsteam commits of patches 2,3, and 4 are: > >> 2: 3c58f737231e "scsi: target: tcmu: Optimize use of flush_dcache_page" > >> 3: 3145550a7f8b "scsi: target: tcmu: Fix crash in tcmu_flush_dcache_range > >> on ARM" > >> 4: 5a0c256d96f0 "scsi: target: tcmu: Fix crash on ARM during cmd > >> completion" > >> > >> Since patches 3 and 4 already were accepted for 5.8, 5.4, and 4.19, and > >> I sent a request to add patch 2 about 1 hour ago, please consider adding > >> this patch to 5.4 and 4.19, because without it tcmu on ARM will still > >> crash. > > > > I don't see such a request, and am confused now. > > > > What exact commits do you want backported, and to what trees? > > > > thanks, > > > > greg k-h > > > > Sorry for the confusion. > > The subject of the request I mentioned is > "Re: [PATCH v2 0/2] scsi: target: tcmu: fix crashes on ARM" > because it is for the first patch of a small series of two. > > Please backport to kernels 4.19 and 5.4 (it is part of 5.8 from beginning): > 8c4e0f212398 "scsi: target: tcmu: fix size in calls to tcmu_flush_dcache_range" > > Please backport to kernels 4.19, 5.4 and 5.8: > 3c58f737231e "scsi: target: tcmu: Optimize use of flush_dcache_page" > > Backporting to 4.14 or earlier AFAICS would need more work, especially testing. > I don't think that its worth it. Thanks, both now queued up. greg k-h