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=-7.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 CC4BCC4338F for ; Tue, 24 Aug 2021 19:10:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6FF916138B for ; Tue, 24 Aug 2021 19:10:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6FF916138B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 043FF6B006C; Tue, 24 Aug 2021 15:10:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F37A86B0071; Tue, 24 Aug 2021 15:09:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E246E8D0001; Tue, 24 Aug 2021 15:09:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0225.hostedemail.com [216.40.44.225]) by kanga.kvack.org (Postfix) with ESMTP id C5A226B006C for ; Tue, 24 Aug 2021 15:09:59 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 7C3A38249980 for ; Tue, 24 Aug 2021 19:09:59 +0000 (UTC) X-FDA: 78510914118.24.9FA3998 Received: from mail-ej1-f43.google.com (mail-ej1-f43.google.com [209.85.218.43]) by imf16.hostedemail.com (Postfix) with ESMTP id 40577F00009D for ; Tue, 24 Aug 2021 19:09:59 +0000 (UTC) Received: by mail-ej1-f43.google.com with SMTP id i21so5187663ejd.2 for ; Tue, 24 Aug 2021 12:09:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=VGiZpft4TGFevZ6VBGb5LQZhuit7rOqCKoP3Bomq18c=; b=DDHE5zeECmRZNcALFaBWPLf9sR21yu6l0PHvHNWkzzaryO1X/ttVAiGxZoLGNCd6Sn aPk0W0CR53XlcnYyGBqp9G6a7wJCcZYfBQUGj/RumNYCGnzmok/TeBDzaTtRuJAsmaOz bZ2ahDGjD5+XKJV7nb/l7NLNQ9LAc9520TNLwgacVCHUgPADZ0d9CvveHAK+4R9dogQr hkmxm+v4F5gxqT/+A747bThnUaLMMcRKF7v1FXdVnwmQaYiAdz1XdEkXmXsh08KHwzEw nfSuLWmvYAh4SRU4IZa9LjFATgGxsV11gQ5KDM3Vg8uYh4cDph8uiRzKVbMl11DkmAg1 dFWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VGiZpft4TGFevZ6VBGb5LQZhuit7rOqCKoP3Bomq18c=; b=i7H/LN4uP/01syK9JxViOJpU4p61cKXgdYSzTGqy1UzV4Obs5F7sdSXH71cZ5+mLY4 72rDHngPC3lR0b6p4wqYKRuezfpBuxPJxr1atmx4oB7pz2QciEzwIp1HvQ8aLGkRgLYn woRbMJLWkz8jNt/XNMZ807rJhaOMM0Y121RmK3a0McsE8IBV9lhDq1cqKG7XNwh9GcDk VzAr2IeGE8YqOlsrMiswdlgmyNW2mh7yckW4JpPudUbCT7pcAq28tSmO45xLjegMTO+3 n9r0s5pITjn+HcTcmgT1DMNiatqD8ViSkn+7Rtuh8hdtxq9ZFIxWNCdnlNrlphfeIm6j 9aIg== X-Gm-Message-State: AOAM530cGWIv98YV2XmzkLjO4H5rz3X5gEAJSNwii3CNXba8pcthYKoW 1IgaC8eBmKGjCtQu6rgcL0RXN30FgZZOFAs6ZhY= X-Google-Smtp-Source: ABdhPJzMNULv0xUUtcBfXmHqOolWupDvJqc+H+3nNN+2EEliimKRqaOCKm6gTyzncksHHCEX13f9YBhLumL5tMZPhk4= X-Received: by 2002:a17:906:1f82:: with SMTP id t2mr41651061ejr.499.1629832197896; Tue, 24 Aug 2021 12:09:57 -0700 (PDT) MIME-Version: 1.0 References: <00000000000030563005ca006ffd@google.com> <03606e7d-dc38-a439-cd39-3f62b5739db0@suse.cz> In-Reply-To: <03606e7d-dc38-a439-cd39-3f62b5739db0@suse.cz> From: Yang Shi Date: Tue, 24 Aug 2021 12:09:45 -0700 Message-ID: Subject: Re: [syzbot] WARNING in split_huge_page_to_list To: Vlastimil Babka Cc: syzbot , Andrew Morton , Linux Kernel Mailing List , Linux MM , syzkaller-bugs@googlegroups.com, "Kirill A. Shutemov" , Hugh Dickins Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=gmail.com header.s=20161025 header.b=DDHE5zeE; spf=pass (imf16.hostedemail.com: domain of shy828301@gmail.com designates 209.85.218.43 as permitted sender) smtp.mailfrom=shy828301@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 40577F00009D X-Stat-Signature: hefwtjpm3tuyb3wtmqiuani4kw3ufucb X-HE-Tag: 1629832199-541877 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Aug 24, 2021 at 4:41 AM Vlastimil Babka wrote: > > That's VM_WARN_ON_ONCE_PAGE(page_mapped(page), page); > CC folks involved in 504e070dc08f ("mm: thp: replace DEBUG_VM BUG with VM_WARN > when unmap fails for split") There might be race between THP split and page unmap, and THP split code can handle it, so it is not worth a VM_BUG. Hugh fixed a couple of potential races, but there might be others. > > On 8/20/21 18:48, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: f87d64319e6f Merge tag 'net-5.14-rc7' of git://git.kernel... > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=1205bd55300000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=3205625db2f96ac9 > > dashboard link: https://syzkaller.appspot.com/bug?extid=0c65e03871b364e714a3 > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+0c65e03871b364e714a3@syzkaller.appspotmail.com > > > > __do_munmap+0x627/0x11c0 mm/mmap.c:2911 > > do_munmap mm/mmap.c:2922 [inline] > > munmap_vma_range mm/mmap.c:604 [inline] > > mmap_region+0x85a/0x1760 mm/mmap.c:1753 > > do_mmap+0x86e/0x1180 mm/mmap.c:1584 > > vm_mmap_pgoff+0x1b7/0x290 mm/util.c:519 > > ksys_mmap_pgoff+0x4a8/0x620 mm/mmap.c:1635 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x44/0xae > > ------------[ cut here ]------------ > > WARNING: CPU: 0 PID: 2144 at mm/huge_memory.c:2327 unmap_page mm/huge_memory.c:2327 [inline] > > WARNING: CPU: 0 PID: 2144 at mm/huge_memory.c:2327 split_huge_page_to_list+0x25eb/0x3e60 mm/huge_memory.c:2700 > > Modules linked in: > > CPU: 0 PID: 2144 Comm: kswapd1 Not tainted 5.14.0-rc6-syzkaller #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > RIP: 0010:unmap_page mm/huge_memory.c:2327 [inline] > > RIP: 0010:split_huge_page_to_list+0x25eb/0x3e60 mm/huge_memory.c:2700 > > Code: 89 de e8 28 e1 b6 ff 84 db 0f 85 54 e0 ff ff e8 6b d9 b6 ff 48 c7 c6 e0 d8 97 89 48 89 ef e8 9c 72 e9 ff c6 05 05 dd 99 0b 01 <0f> 0b e9 32 e0 ff ff bb 02 00 00 00 e9 64 ef ff ff e8 3f d9 b6 ff > > RSP: 0018:ffffc900084f76d8 EFLAGS: 00010293 > > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > > RDX: ffff88801c44c000 RSI: ffffffff81be0514 RDI: 0000000000000003 > > RBP: ffffea00021c0000 R08: 0000000000000029 R09: 00000000ffffffff > > R10: ffffffff88ea7679 R11: 00000000ffffffff R12: ffff88814018d2d8 > > R13: ffffea00021c0008 R14: ffffea00021c0000 R15: 0000000000000000 > > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00007f14895d5000 CR3: 0000000017350000 CR4: 00000000001506f0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > split_huge_page include/linux/huge_mm.h:192 [inline] > > deferred_split_scan+0x5fa/0xbd0 mm/huge_memory.c:2860 > > do_shrink_slab+0x42d/0xbd0 mm/vmscan.c:709 > > shrink_slab+0x17c/0x6e0 mm/vmscan.c:869 > > shrink_node_memcgs mm/vmscan.c:2868 [inline] > > shrink_node+0x8d1/0x1df0 mm/vmscan.c:2983 > > kswapd_shrink_node mm/vmscan.c:3726 [inline] > > balance_pgdat+0x7ce/0x13b0 mm/vmscan.c:3917 > > kswapd+0x5b6/0xdb0 mm/vmscan.c:4176 > > kthread+0x3e5/0x4d0 kernel/kthread.c:319 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > > > > > > --- > > This report is generated by a bot. It may contain errors. > > See https://goo.gl/tpsmEJ for more information about syzbot. > > syzbot engineers can be reached at syzkaller@googlegroups.com. > > > > syzbot will keep track of this issue. See: > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > >