Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751682AbdG0J4S (ORCPT ); Thu, 27 Jul 2017 05:56:18 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:10287 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751671AbdG0J4Q (ORCPT ); Thu, 27 Jul 2017 05:56:16 -0400 From: Gu Zheng Subject: trinity test fanotify cause hungtasks on kernel 4.13 To: CC: Zhaohongjiang , "miaoxie@huawei.com" , Qiuxishi , Message-ID: <5979B8A5.205@huawei.com> Date: Thu, 27 Jul 2017 17:55:49 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.97.87] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020201.5979B8B8.00E2,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 0eb3023a9b3f835f9d870b1440bf89fd Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4113 Lines: 77 hi,Eric Paris: when we used the trinity test the fanotify interfaces, it cause many hungtasks. CONFIG_FANOTIFY_ACCESS_PERMISSIONS=y the shell is simple: 1 #!/bin/bash 2 3 while true 4 do 5 ./trinity -c fanotify_init -l off -C 2 -X > /dev/null 2>&1 & 6 sleep 1 7 ./trinity -c fanotify_mark -l off -C 2 -X > /dev/null 2>&1 & 8 sleep 10 9 done we found the trinity enter the D state fastly. we check the pids'stack [root@localhost ~]# ps -aux | grep D USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 977 0.0 0.0 207992 7904 ? Ss 15:23 0:00 /usr/bin/abrt-watch-log -F BUG: WARNING: at WARNING: CPU: INFO: possible recursive locking detected ernel BUG at list_del corruption list_add corruption do_IRQ: stack overflow: ear stack overflow (cur: eneral protection fault nable to handle kernel ouble fault: RTNL: assertion failed eek! page_mapcount(page) went negative! adness at NETDEV WATCHDOG ysctl table check failed : nobody cared IRQ handler type mismatch Machine Check Exception: Machine check events logged divide error: bounds: coprocessor segment overrun: invalid TSS: segment not present: invalid opcode: alignment check: stack segment: fpu exception: simd exception: iret exception: /var/log/messages -- /usr/bin/abrt-dump-oops -xtD root 997 0.0 0.0 203360 3188 ? Ssl 15:23 0:00 /usr/sbin/gssproxy -D root 1549 0.0 0.0 82552 6012 ? Ss 15:23 0:00 /usr/sbin/sshd -D root 2807 3.5 0.2 59740 35416 pts/0 DL 15:24 0:00 ./trinity -c fanotify_init -l off -C 2 -X root 2809 3.1 0.2 53712 35332 pts/0 DL 15:24 0:00 ./trinity -c fanotify_mark -l off -C 2 -X root 2915 0.0 0.0 136948 1776 pts/0 D 15:24 0:00 ps ax root 2919 0.0 0.0 112656 2100 pts/1 S+ 15:24 0:00 grep --color=auto D [root@localhost ~]# cat /proc/2807/stack [] fanotify_handle_event+0x2a1/0x2f0 [] fsnotify+0x2d3/0x4f0 [] security_file_open+0x89/0x90 [] do_dentry_open+0x139/0x330 [] vfs_open+0x4f/0x70 [] path_openat+0x548/0x1350 [] do_filp_open+0x91/0x100 [] do_sys_open+0x124/0x210 [] SyS_open+0x1e/0x20 [] do_syscall_64+0x67/0x150 [] entry_SYSCALL64_slow_path+0x25/0x25 [] 0xffffffffffffffff [root@localhost ~]# cat /proc/2915/stack [] fanotify_handle_event+0x2a1/0x2f0 [] fsnotify+0x2d3/0x4f0 [] security_file_open+0x89/0x90 [] do_dentry_open+0x139/0x330 [] vfs_open+0x4f/0x70 [] path_openat+0x548/0x1350 [] do_filp_open+0x91/0x100 [] do_sys_open+0x124/0x210 [] SyS_open+0x1e/0x20 [] do_syscall_64+0x67/0x150 [] entry_SYSCALL64_slow_path+0x25/0x25 [] 0xffffffffffffffff [root@localhost ~]# cat /proc/2809/stack [] fanotify_handle_event+0x2a1/0x2f0 [] fsnotify+0x2d3/0x4f0 [] security_file_open+0x89/0x90 [] do_dentry_open+0x139/0x330 [] vfs_open+0x4f/0x70 [] path_openat+0x548/0x1350 [] do_filp_open+0x91/0x100 [] do_sys_open+0x124/0x210 [] SyS_open+0x1e/0x20 [] do_syscall_64+0x67/0x150 [] entry_SYSCALL64_slow_path+0x25/0x25 [] 0xffffffffffffffff all pids wait for the response in fanotify_handle_event->fanotify_get_response, but the monitor can not replay anything ,becauseof the permission or killed monitor then the others will be stucked who use the fanotify or synchronize_srcu if we disable the CONFIG_FANOTIFY_ACCESS_PERMISSIONS, the mem will be consumed quickly, because the fsnotify_mark_srcu read lock always be hold. if add a timeout , the safety can not be guaranteed. do you have any ideas? thanks.