From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zdenek Kabelac Date: Wed, 20 Jan 2010 13:53:51 +0100 Subject: [PATCH] dmeventd coredump fix In-Reply-To: <4B5065D4.10108@redhat.com> References: <4B4EDBDF.7070509@redhat.com> <4B5065D4.10108@redhat.com> Message-ID: <4B56FCDF.3060207@redhat.com> List-Id: To: lvm-devel@redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Dne 15.1.2010 13:55, Zdenek Kabelac napsal(a): > Dne 14.1.2010 09:54, Zdenek Kabelac napsal(a): >> Hi >> >> I've noticed that on my test machine dmeventd generates quite often weird >> coredumps with somewhat strange backtraces. >> >> Thus I've searched for the reason and with valgrind trace I've noticed >> problem with struct cmdline_context _cmdline >> >> Thread 2: >> Conditional jump or move depends on uninitialised value(s) >> at 0x4C9B826: free (vg_replace_malloc.c:325) >> by 0x751C86F: lvm_fin (lvmcmdline.c:1213) >> by 0x7537ACC: lvm2_exit (lvmcmdlib.c:116) >> by 0x7365BEE: unregister_device (dmeventd_mirror.c:316) >> by 0x804AAFE: _monitor_unregister (dmeventd.c:664) >> by 0x804B853: _monitor_thread (dmeventd.c:805) >> by 0x4CBC584: start_thread (pthread_create.c:300) >> by 0x6EA426D: clone (clone.S:130) >> >> Invalid free() / delete / delete[] >> at 0x4C9B866: free (vg_replace_malloc.c:325) >> by 0x751C86F: lvm_fin (lvmcmdline.c:1213) >> by 0x7537ACC: lvm2_exit (lvmcmdlib.c:116) >> by 0x7365BEE: unregister_device (dmeventd_mirror.c:316) >> by 0x804AAFE: _monitor_unregister (dmeventd.c:664) >> by 0x804B853: _monitor_thread (dmeventd.c:805) >> by 0x4CBC584: start_thread (pthread_create.c:300) >> by 0x6EA426D: clone (clone.S:130) >> Address 0x51 is not stack'd, malloc'd or (recently) free'd >> >> Crash seems to appear when mirror device is reregistered during our test suit. >> Not really sure if it's related to some other reported problems. >> >> Basically we need to clear commands_size & num_commands and >> it doesn't matter if it is in init or finish - >> >> I'm proposing this oneline patch: >> >> --- tools/lvmcmdline.c 11 Jan 2010 19:19:17 -0000 1.111 >> +++ tools/lvmcmdline.c 14 Jan 2010 08:33:50 -0000 >> -1192,6 +1192,7 @@ struct cmd_context *init_lvm(void) >> { >> struct cmd_context *cmd; >> >> + memset(&_cmdline, 0, sizeof(_cmdline)); >> _cmdline.the_args = &_the_args[0]; >> >> if (!(cmd = create_toolcontext(0, NULL))) >> > > Ok - patch above has some problems with order of calling lvm2_init() calls; > > So here comes simpler version which only clears structure elements right after > they are being released: > > --- tools/lvmcmdline.c 11 Jan 2010 19:19:17 -0000 1.111 > +++ tools/lvmcmdline.c 15 Jan 2010 12:51:58 -0000 > @@ -1213,6 +1213,10 @@ static void _fin_commands(void) > dm_free(_cmdline.commands[i].valid_args); > > dm_free(_cmdline.commands); > + > + _cmdline.commands = NULL; > + _cmdline.num_commands = 0; > + _cmdline.commands_size = 0; > } > > void lvm_fin(struct cmd_context *cmd) Issue is now being tracked at: https://bugzilla.redhat.com/show_bug.cgi?id=557104 Zdenek