From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1768295AbcHROkm (ORCPT ); Thu, 18 Aug 2016 10:40:42 -0400 Received: from mail-it0-f51.google.com ([209.85.214.51]:36822 "EHLO mail-it0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1767507AbcHROkh (ORCPT ); Thu, 18 Aug 2016 10:40:37 -0400 From: Vince Weaver X-Google-Original-From: Vince Weaver Date: Thu, 18 Aug 2016 10:32:48 -0400 (EDT) X-X-Sender: vince@macbook-air To: linux-kernel@vger.kernel.org cc: Borislav Petkov , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo Subject: perf: fuzzer crashes immediately on AMD system Message-ID: User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tried the perf_fuzzer on my A10 fam15h/model13h system with 4.8-rc2 and it falls over more or less immediately. This maps to variable_test_bit() called by ctx = find_get_context(pmu, task, event); in kernel/events/core.c:9467 It happens quickly enough I can probably track down the exact event that causes this, if needed. [ 101.970659] BUG: unable to handle kernel paging request at ffffffff8653d8a0 [ 101.977676] IP: [] find_get_context.isra.75+0x28/0x20f [ 101.984405] PGD 2807067 PUD 2808063 PMD 0 [ 101.988563] Oops: 0000 [#1] SMP [ 102.069521] CPU: 0 PID: 2205 Comm: perf_fuzzer Not tainted 4.8.0-rc2+ #27 [ 102.076313] Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013 [ 102.085268] task: ffff880223ae5000 task.stack: ffff880224ea8000 [ 102.091188] RIP: 0010:[] [] find_get_context.isra.75+0x28/0x20f [ 102.100339] RSP: 0018:ffff880224eabe20 EFLAGS: 00010246 [ 102.105657] RAX: 000000002633e300 RBX: 0000000000000000 RCX: 000000002633e300 [ 102.112795] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8180ea00 [ 102.119929] RBP: ffffffff8180ea00 R08: 0000000000000004 R09: 0000000000000000 [ 102.127063] R10: 0000000000000003 R11: 0000000000000246 R12: 000000002633e300 [ 102.134196] R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff8180ea00 [ 102.141327] FS: 00007f743b391700(0000) GS:ffff88022ec00000(0000) knlGS:0000000000000000 [ 102.149416] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 102.155167] CR2: ffffffff8653d8a0 CR3: 00000002255b9000 CR4: 00000000000407f0 [ 102.162309] Stack: [ 102.164323] 0000000000000000 00000000ffffffff ffff880223b9d800 ffff880224fdd000 [ 102.171804] ffff880223b9d800 0000000000000000 0000000000000000 0000000000000000 [ 102.179284] ffffffff8180ea00 ffffffff810e72be ffffffff00000002 ffff88022e0006c0 [ 102.186765] Call Trace: [ 102.189216] [] ? SYSC_perf_event_open+0x525/0xa34 [ 102.195579] [] ? entry_SYSCALL_64_fastpath+0x17/0x93 [ 102.202203] Code: 41 5c c3 41 57 41 56 41 55 41 54 55 53 48 89 fd 48 89 f3 48 83 ec 18 48 85 f6 75 6c 83 3d 2f 2a 7f 00 00 41 89 cc 7f 1e 44 89 e0 <48> 0f a3 05 87 0f 7f 00 0f 92 c0 84 c0 75 26 48 c7 c0 ed ff ff [ 102.222256] RIP [] find_get_context.isra.75+0x28/0x20f [ 102.229065] RSP [ 102.232556] CR2: ffffffff8653d8a0 [ 102.235879] ---[ end trace fa649074c022bab1 ]---