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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 80729C5ACBF for ; Fri, 13 Mar 2020 21:43:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5124820663 for ; Fri, 13 Mar 2020 21:43:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ClOsabtY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727511AbgCMVnp (ORCPT ); Fri, 13 Mar 2020 17:43:45 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:57426 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726534AbgCMVnp (ORCPT ); Fri, 13 Mar 2020 17:43:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584135823; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=z+yNqTPhCKvphPybR67u1KFL4j6tDivUDXMnB6tP/Oo=; b=ClOsabtYUV0ZxHw7znGKkIW/RWZkLDy2b8ZNxIGImMOcGo8A/igsT6OhOkOWWaixA2ja97 Pl/OKhlF5m1l3hdWHXjG3Tgv27qRevlwYs92F2toYr2+/p4jBnvyyWgrNddzn89dHli2dl OgUU224l2Gr7qA9JeRf6N7Wkd/EZ9Yg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-212-SS9mUficM269v4rFOovXnQ-1; Fri, 13 Mar 2020 17:43:40 -0400 X-MC-Unique: SS9mUficM269v4rFOovXnQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 54850800D48; Fri, 13 Mar 2020 21:43:37 +0000 (UTC) Received: from t490s (ovpn-120-126.rdu2.redhat.com [10.10.120.126]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3686B9A6A; Fri, 13 Mar 2020 21:43:36 +0000 (UTC) Date: Fri, 13 Mar 2020 17:43:32 -0400 From: Rafael Aquini To: Qian Cai Cc: akpm@linux-foundation.org, ying.huang@intel.com, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] page-flags: fix a crash at SetPageError(THP_SWAP) Message-ID: <20200313214332.GA14055@t490s> References: <20200310235846.1319-1-cai@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200310235846.1319-1-cai@lca.pw> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Mar 10, 2020 at 07:58:46PM -0400, Qian Cai wrote: > The commit bd4c82c22c36 ("mm, THP, swap: delay splitting THP after > swapped out") supported writing THP to a swap device but forgot to > upgrade an older commit df8c94d13c7e ("page-flags: define behavior of > FS/IO-related flags on compound pages") which could trigger a crash > during THP swapping out with DEBUG_VM_PGFLAGS=y, > > kernel BUG at include/linux/page-flags.h:317! > > page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page)) > page:fffff3b2ec3a8000 refcount:512 mapcount:0 mapping:000000009eb0338c > index:0x7f6e58200 head:fffff3b2ec3a8000 order:9 compound_mapcount:0 > compound_pincount:0 > anon flags: > 0x45fffe0000d8454(uptodate|lru|workingset|owner_priv_1|writeback|head|reclaim|swapbacked) > > end_swap_bio_write() > SetPageError(page) > VM_BUG_ON_PAGE(1 && PageCompound(page)) > > > bio_endio+0x297/0x560 > dec_pending+0x218/0x430 [dm_mod] > clone_endio+0xe4/0x2c0 [dm_mod] > bio_endio+0x297/0x560 > blk_update_request+0x201/0x920 > scsi_end_request+0x6b/0x4b0 > scsi_io_completion+0x509/0x7e0 > scsi_finish_command+0x1ed/0x2a0 > scsi_softirq_done+0x1c9/0x1d0 > __blk_mqnterrupt+0xf/0x20 > > > Fix by checking PF_NO_TAIL in those places instead. > > Fixes: bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped out") > Cc: > Signed-off-by: Qian Cai > --- > include/linux/page-flags.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > index 1bf83c8fcaa7..77de28bfefb0 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -311,7 +311,7 @@ static inline int TestClearPage##uname(struct page *page) { return 0; } > > __PAGEFLAG(Locked, locked, PF_NO_TAIL) > PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) > -PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND) > +PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL) > PAGEFLAG(Referenced, referenced, PF_HEAD) > TESTCLEARFLAG(Referenced, referenced, PF_HEAD) > __SETPAGEFLAG(Referenced, referenced, PF_HEAD) > -- > 2.21.0 (Apple Git-122.2) > Acked-by: Rafael Aquini