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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 B9C31C47404 for ; Wed, 9 Oct 2019 22:21:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8C26D206BB for ; Wed, 9 Oct 2019 22:21:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ge3Vk7Nw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732194AbfJIWVY (ORCPT ); Wed, 9 Oct 2019 18:21:24 -0400 Received: from mail-yb1-f194.google.com ([209.85.219.194]:34707 "EHLO mail-yb1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730675AbfJIWVY (ORCPT ); Wed, 9 Oct 2019 18:21:24 -0400 Received: by mail-yb1-f194.google.com with SMTP id m1so1285657ybm.1 for ; Wed, 09 Oct 2019 15:21:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+jCnGm7PUG2F0SslkVqMaEPLtH+hwOGFg3tRY7sPh28=; b=Ge3Vk7NwYEw+wRRG3HfPs2s+Ito+W67fwNHCe4jTP89HOyGh8BLwroYSsnlYLKd1wm Kvw+tm6vzzCAJTrxKlqnrRJ8ouq1eQJuVXZsAZ+I/s2tPzFOTca5R3ZgosdKIV2Rtat+ LzjowDRc8UB38Xo6O0SfmM50IQFCNYrYly+Ev6D1c1CRJNKuy+DIm9KkEbst3k0KQPml do17FYygbJ/prjadQUVE+6Xa5uTs7oBA/GFSIYNvXLTFcD73OnUulUzAmSAk61yeKpir UV3Z7PKfLf2zU6MvzP+uAB/uKMzQhIiVetW5Dwoz8o/OBgs6revwI4AWtiobPBFH0Wwr Kjbw== 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=+jCnGm7PUG2F0SslkVqMaEPLtH+hwOGFg3tRY7sPh28=; b=my3bKjVR1aiQvk4dxc0T+8xSuo/Y4UUHS3ZZ0UguyXfiPOOcnbWhPbCraobLLECwnJ 5zsHVe5NxPrfrDRrXblCzZ0xW5FBrkkIs/30egrHFViQjV55PM/mze8b1T+Y5VYYOpxd IUHqQdGZ80rIur7SpgyKyCllHB7MgFNTpArEfOlxLMmg8IfK0UiwvSHqlvP3rPjm637X 6XEbTQhSJtxlqQIp0rj7tnHmUYzfovcVF3kOV4OfM3orkhMWUiGmt6ajZTj0u16cKwVa E7I+iTizKwzubd8IwP+zUMyTveTg6NcBQJxIVei0YC04W7V3mIunskZPl2GyeIZ1iobE cPLw== X-Gm-Message-State: APjAAAVn3iSMXlQTmyPYiLlHV9msTFEuJKQBfWlt0BZO5xqRKBGSXfjw mu858MM9t2V4DfLPf+08krIN8u5jLonJ9V6EFKMNRw== X-Google-Smtp-Source: APXvYqzo/vtc2XGgUsupaV8eDIFv8SqGTCa8haGgMBNwrgmdJMXkQoeQNHdDjYxFnqV23ig+G+XvWQf+HJAJP+Xeh9c= X-Received: by 2002:a25:bc49:: with SMTP id d9mr3833504ybk.293.1570659682127; Wed, 09 Oct 2019 15:21:22 -0700 (PDT) MIME-Version: 1.0 References: <1570656570.5937.24.camel@lca.pw> In-Reply-To: <1570656570.5937.24.camel@lca.pw> From: Shakeel Butt Date: Wed, 9 Oct 2019 15:21:11 -0700 Message-ID: Subject: Re: "reuse mergeable anon_vma as parent when fork" causes a crash on s390 To: Qian Cai Cc: Wei Yang , Andrew Morton , Konstantin Khlebnikov , Rik van Riel , Linux MM , LKML , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , linux-s390@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 9, 2019 at 2:30 PM Qian Cai wrote: > > The linux-next commit "mm/rmap.c: reuse mergeable anon_vma as parent when fork" > [1] causes a crash on s390 while compiling some C code. Reverted it fixes the > issue. > > [1] https://lore.kernel.org/lkml/20191004160632.30251-1-richardw.yang@linux.intel.com/ > > 00: [ 330.681233] vma 0000000049a08008 start 000003ff8ee7f000 end 000003ff8eee4 > 00: 000 > 00: [ 330.681233] next 000000004f272008 prev 0000000065c84230 mm 0000000037d1c1 > 00: 00 > 00: [ 330.681233] prot 711 anon_vma 000000001f4e4a80 vm_ops 0000000000000000 > 00: [ 330.681233] pgoff 3ff8ee7f file 0000000000000000 private_data 00000000000 > 00: 00000 > 00: [ 330.681233] flags: 0x8100073(read|write|mayread|maywrite|mayexec|account| > 00: softdirty) > 00: [ 330.681344] ------------[ cut here ]------------ > 00: [ 330.681357] kernel BUG at include/linux/rmap.h:159! > 00: [ 330.681442] illegal operation: 0001 ilc:1 [#1] SMP DEBUG_PAGEALLOC > 00: [ 330.681460] Modules linked in: ip_tables x_tables xfs dasd_fba_mod dasd_e > 00: ckd_mod dm_mirror dm_region_hash dm_log dm_mod > 00: [ 330.681502] CPU: 0 PID: 7651 Comm: cc1 Not tainted 5.4.0-rc2-next-2019100 > 00: 9+ #4 > 00: [ 330.681516] Hardware name: IBM 2964 N96 400 (z/VM 6.4.0) > 00: [ 330.681530] Krnl PSW : 0704c00180000000 00000000531d9cac (__vma_adjust+0x > 00: cf4/0xf30) > 00: [ 330.681561] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 > 00: RI:0 EA:3 > 00: [ 330.681579] Krnl GPRS: 0000000000000001 0000030000000000 0000000000000146 > 00: 000000006cc03da4 > 00: [ 330.681595] 0000030000000000 000000005304378c 00000000513de008 > 00: 0000000000000000 > 00: [ 330.681611] 0000000049a08008 0000000049a08080 0000000000000000 > 00: 000000005a178438 > 00: [ 330.681627] 0000000053bae3b0 0000000037d1c100 00000000531d9ca8 > 00: 00000000235ef880 > 01: HCPGSP2629I The virtual machine is placed in CP mode due to a SIGP stop from > CPU 01. > 01: HCPGSP2629I The virtual machine is placed in CP mode due to a SIGP stop from > CPU 00. > 00: [ 330.681668] Krnl Code: 00000000531d9c9c: fae0b9040028 ap 2308 > 00: (15,%r11),40(1,%r0) > 00: [ 330.681668] 00000000531d9ca2: c0e5ffff145f brasl %r14 > 00: ,531bc560 > 00: [ 330.681668] #00000000531d9ca8: a7f40001 brc 15,5 > 00: 31d9caa > 00: [ 330.681668] >00000000531d9cac: c020005f1a5a larl %r2, > 00: 53dbd160 > 00: [ 330.681668] 00000000531d9cb2: c0e50015ec2b brasl %r14 > 00: ,53497508 > 00: [ 330.681668] 00000000531d9cb8: e320f0d80004 lg %r2, > 00: 216(%r15) > 00: [ 330.681668] 00000000531d9cbe: c0e500040de1 brasl %r14 > 00: ,5325b880 > 00: [ 330.681668] 00000000531d9cc4: 4120d038 la %r2, > 00: 56(%r13) > 00: [ 330.682579] Call Trace: > 00: [ 330.682665] ([<00000000531d9ca8>] __vma_adjust+0xcf0/0xf30) > 00: [ 330.682684] [<00000000531da4f0>] vma_merge+0x608/0x6b8 > 00: [ 330.682699] [<00000000531de3b8>] mmap_region+0x1e0/0x9b0 > 00: [ 330.682713] [<00000000531defec>] do_mmap+0x464/0x650 > 00: [ 330.682730] [<00000000531930ba>] vm_mmap_pgoff+0x132/0x1c0 > 00: [ 330.682745] [<00000000531da7b4>] ksys_mmap_pgoff+0xd4/0x458 > 00: [ 330.682761] [<00000000531dac54>] __s390x_sys_old_mmap+0xdc/0x108 > 00: [ 330.682779] [<00000000537dcdd0>] system_call+0xd8/0x2b4 > 00: [ 330.682791] INFO: lockdep is turned off. > 00: [ 330.682801] Last Breaking-Event-Address: > 00: [ 330.682815] [<00000000531d9ca8>] __vma_adjust+0xcf0/0xf30 > 00: [ 330.682833] Kernel panic - not syncing: Fatal exception: panic_on_oops Our internal syzbot instance also hit this bug and bisected to the same patch. Report: [ 74.249839][ T8601] vma ffff88808c0f7eb0 start 0000000020000000 end 0000000021000000 [ 74.249839][ T8601] next ffff888095f5e568 prev ffff888091279318 mm ffff8880894555c0 [ 74.249839][ T8601] prot 25 anon_vma ffff88809a9c4b40 vm_ops 0000000000000000 [ 74.249839][ T8601] pgoff 20000 file 0000000000000000 private_data 0000000000000000 [ 74.249839][ T8601] flags: 0x8100077(read|write|exec|mayread|maywrite|mayexec|account|softdirty) [ 74.289454][ T8601] ------------[ cut here ]------------ [ 74.294941][ T8601] kernel BUG at include/linux/rmap.h:159! [ 74.301474][ T8601] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 74.307549][ T8601] CPU: 0 PID: 8601 Comm: syz-executor.0 Not tainted 5.4.0-rc2-next-20191008 #0 [ 74.316453][ T8601] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 74.327161][ T8601] RIP: 0010:__vma_adjust+0x151c/0x1cc0 [ 74.332604][ T8601] Code: 4c 89 ee 4c 89 f7 e8 b3 01 d2 ff 4d 39 ee 0f 82 1b fe ff ff 45 31 ed e9 1b fe ff ff e8 7d 00 d2 ff 48 8b 7d c8 e8 76 62 fc ff <0f> 0b e8 6d 00 d2 ff 48 8b 85 68 ff ff ff 80 38 00 0f 85 20 07 00 [ 74.352189][ T8601] RSP: 0018:ffff8880a0e9f9c0 EFLAGS: 00010286 [ 74.358232][ T8601] RAX: 0000000000000147 RBX: dffffc0000000000 RCX: 0000000000000000 [ 74.366180][ T8601] RDX: 0000000000000000 RSI: ffffffff815cb676 RDI: ffffed10141d3f12 [ 74.374126][ T8601] RBP: ffff8880a0e9fa88 R08: 0000000000000147 R09: ffffed1015d06161 [ 74.382076][ T8601] R10: ffffed1015d06160 R11: ffff8880ae830b07 R12: ffff888095f28e10 [ 74.390054][ T8601] R13: ffff88808c0f7f18 R14: 0000000000000000 R15: 0000000000000001 [ 74.398014][ T8601] FS: 0000000000c57940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 74.406918][ T8601] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 74.413491][ T8601] CR2: 0000000020d06000 CR3: 0000000090f89000 CR4: 00000000001406f0 [ 74.421447][ T8601] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 74.429403][ T8601] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 74.437348][ T8601] Call Trace: [ 74.440625][ T8601] vma_merge+0xb8a/0xe60 [ 74.444848][ T8601] ? __vma_adjust+0x1cc0/0x1cc0 [ 74.449677][ T8601] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 74.455369][ T8601] ? __vm_enough_memory+0x1b7/0x390 [ 74.460542][ T8601] mmap_region+0x3e0/0x1760 [ 74.465025][ T8601] ? __x64_sys_brk+0x760/0x760 [ 74.469766][ T8601] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 74.475991][ T8601] ? get_unmapped_area+0x2ad/0x3d0 [ 74.481075][ T8601] do_mmap+0x853/0x1190 [ 74.485216][ T8601] vm_mmap_pgoff+0x1c5/0x230 [ 74.489784][ T8601] ? randomize_stack_top+0x110/0x110 [ 74.495044][ T8601] ? __kasan_check_read+0x11/0x20 [ 74.500042][ T8601] ? _copy_to_user+0x118/0x160 [ 74.504782][ T8601] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 74.511007][ T8601] ksys_mmap_pgoff+0xf7/0x630 [ 74.515662][ T8601] ? find_mergeable_anon_vma+0x2e0/0x2e0 [ 74.521295][ T8601] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 74.526735][ T8601] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 74.532181][ T8601] ? do_syscall_64+0x26/0x760 [ 74.536835][ T8601] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 74.542881][ T8601] __x64_sys_mmap+0xe9/0x1b0 [ 74.547448][ T8601] do_syscall_64+0xfa/0x760 [ 74.551928][ T8601] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 74.557796][ T8601] RIP: 0033:0x459a59 [ 74.561682][ T8601] Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 74.581261][ T8601] RSP: 002b:00007ffcc91b5068 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 [ 74.589731][ T8601] RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459a59 [ 74.597685][ T8601] RDX: ffffffffefffffff RSI: 0000000000004000 RDI: 0000000020196000 [ 74.605632][ T8601] RBP: 000000000075bf20 R08: ffffffffffffffff R09: 0000000000000000 [ 74.613580][ T8601] R10: 0000000000008032 R11: 0000000000000246 R12: 0000000000c57914 [ 74.621527][ T8601] R13: 00000000004c6176 R14: 00000000004db118 R15: 00000000ffffffff [ 74.629486][ T8601] Modules linked in: [ 74.636716][ T8601] ---[ end trace aa2e499bc1c6fb5e ]--- [ 74.642235][ T8601] RIP: 0010:__vma_adjust+0x151c/0x1cc0 [ 74.647787][ T8601] Code: 4c 89 ee 4c 89 f7 e8 b3 01 d2 ff 4d 39 ee 0f 82 1b fe ff ff 45 31 ed e9 1b fe ff ff e8 7d 00 d2 ff 48 8b 7d c8 e8 76 62 fc ff <0f> 0b e8 6d 00 d2 ff 48 8b 85 68 ff ff ff 80 38 00 0f 85 20 07 00 [ 74.667752][ T8601] RSP: 0018:ffff8880a0e9f9c0 EFLAGS: 00010286 [ 74.673806][ T8601] RAX: 0000000000000147 RBX: dffffc0000000000 RCX: 0000000000000000 [ 74.681794][ T8601] RDX: 0000000000000000 RSI: ffffffff815cb676 RDI: ffffed10141d3f12 [ 74.689779][ T8601] RBP: ffff8880a0e9fa88 R08: 0000000000000147 R09: ffffed1015d06161 [ 74.698081][ T8601] R10: ffffed1015d06160 R11: ffff8880ae830b07 R12: ffff888095f28e10 [ 74.706052][ T8601] R13: ffff88808c0f7f18 R14: 0000000000000000 R15: 0000000000000001 [ 74.714061][ T8601] FS: 0000000000c57940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 74.723209][ T8601] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 74.729820][ T8601] CR2: 0000000020d06000 CR3: 0000000090f89000 CR4: 00000000001406f0 [ 74.738021][ T8601] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 74.745972][ T8601] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 74.753968][ T8601] Kernel panic - not syncing: Fatal exception Syzbot reproducer: mmap(&(0x7f0000196000/0x4000)=nil, 0x4000, PROT_NONE, 0x4032 /* flags= MAP_NORESERVE|MAP_ANONYMOUS|MAP_FIXED|PROT_WRITE*/, -1, 0x0) mmap(&(0x7f0000196000/0x4000)=nil, 0x4000, 0xffffffffefffffff, 0x8032 /* flags= MAP_POPULATE|MAP_ANONYMOUS|MAP_FIXED|PROT_WRITE*/, -1, 0x0) Shakeel