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From: Jeff Layton on 26 Jun 2010 08:00
On Sat, 26 Jun 2010 20:47:33 +1000
Andrew Hendry <andrew.hendry(a)gmail.com> wrote:

> sorry, this should say 2.6.35-rc3
>
> On Sat, Jun 26, 2010 at 8:46 PM, Andrew Hendry <andrew.hendry(a)gmail.com> wrote:
> > From 2.6.34-rc3
> > Can't reliably reproduce, this was once after a resume over a few days
> > normal use.
> > The No response for cmds lines are normal as NAS takes a while to spin
> > up after resume.
> > System was unstable after message so couldn't collect more state
> >
> > [18446744028.633263] r8169 0000:0b:02.0: eth0: link up
> > [18446744039.623540] eth0: no IPv6 routers present
> > [18446744041.684522] CIFS VFS: No response for cmd 117 mid 21812
> > [18446744041.684561] CIFS VFS: cifs_mount failed w/return code = -11
> > [18446744056.674016] CIFS VFS: No response for cmd 114 mid 21813
> > [18446744056.674105] CIFS VFS: cifs_mount failed w/return code = -112
> > [18446744060.831668] BUG: unable to handle kernel NULL pointer
> > dereference at 0000000000000048
> > [18446744060.831680] IP: [<ffffffffa02982d9>]
> > cifs_show_options+0xf9/0x480 [cifs]
> > [18446744060.831699] PGD 2068fe067 PUD 2068fd067 PMD 0
> > [18446744060.831710] Oops: 0000 [#1] PREEMPT SMP
> > [18446744060.831720] last sysfs file:
> > /sys/devices/system/cpu/sched_smt_power_savings
> > [18446744060.831729] CPU 4
> > [18446744060.831733] Modules linked in: nls_cp437 cifs fbcon tileblit
> > font bitblit softcursor binfmt_misc kvm_intel kvm snd_hda_codec_via
> > snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss nouveau
> > snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi
> > snd_rawmidi snd_seq_midi_event ttm psmouse snd_seq drm_kms_helper
> > snd_timer snd_seq_device serio_raw snd drm asus_atk0110 soundcore
> > snd_page_alloc i2c_algo_bit usbhid hid ahci r8169 mii libahci
> > pata_jmicron
> > [18446744060.831821]
> > [18446744060.831829] Pid: 2206, comm: udisks-daemon Not tainted
> > 2.6.35-rc3 #6 P7P55D-E PRO/System Product Name
> > [18446744060.831836] RIP: 0010:[<ffffffffa02982d9>]
> > [<ffffffffa02982d9>] cifs_show_options+0xf9/0x480 [cifs]
> > [18446744060.831853] RSP: 0018:ffff880206913dc8 �EFLAGS: 00010246
> > [18446744060.831860] RAX: 0000000000000000 RBX: ffff880184a7f140 RCX:
> > 0000000000000006
> > [18446744060.831867] RDX: 0000000000000006 RSI: 0000000000001000 RDI:
> > ffff880232fb0491
> > [18446744060.831874] RBP: ffff880206913df8 R08: 000000000000fff8 R09:
> > 0000000000000004
> > [18446744060.831881] R10: 0000000000000000 R11: 0000000000000000 R12:
> > ffff880231ad7400
> > [18446744060.831888] R13: ffff8802324d7400 R14: ffff8802324d6b00 R15:
> > 0000000000000000
> > [18446744060.831896] FS: �00007fdb12ceb7a0(0000)
> > GS:ffff880001e80000(0000) knlGS:0000000000000000
> > [18446744060.831904] CS: �0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [18446744060.831910] CR2: 0000000000000048 CR3: 00000002068fb000 CR4:
> > 00000000000006e0
> > [18446744060.831917] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> > 0000000000000000
> > [18446744060.831924] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
> > 0000000000000400
> > [18446744060.831932] Process udisks-daemon (pid: 2206, threadinfo
> > ffff880206912000, task ffff880236ae1680)
> > [18446744060.831939] Stack:
> > [18446744060.831942] �ffff880206913df8 0000000000000000
> > ffff880184a7f140 ffff880184a7f140
> > [18446744060.831954] <0> ffff8802324d6b00 ffff880231ad6400
> > ffff880206913e68 ffffffff811575c7
> > [18446744060.831966] <0> ffffffff8161b450 0000000000000202
> > ffff8802318cac00 ffff88023fa6af00
> > [18446744060.831980] Call Trace:
> > [18446744060.831992] �[<ffffffff811575c7>] show_mountinfo+0x237/0x2b0
> > [18446744060.832004] �[<ffffffff8115bc1f>] seq_read+0x25f/0x3f0
> > [18446744060.832015] �[<ffffffff8113c9f5>] vfs_read+0xb5/0x180
> > [18446744060.832024] �[<ffffffff8113de8f>] ? fget_light+0x7f/0xc0
> > [18446744060.832033] �[<ffffffff8113d331>] sys_read+0x51/0x90
> > [18446744060.832045] �[<ffffffff8100b0f2>] system_call_fastpath+0x16/0x1b
> > [18446744060.832052] Code: 00 48 c7 c6 9a 7e 2c a0 48 89 df 31 c0 e8
> > 80 32 ec e0 49 8b 45 28 48 c7 c6 b0 7e 2c a0 4c 8b 78 40 48 89 df 31
> > c0 e8 67 32 ec e0 <41> 0f b7 47 48 66 83 f8 02 0f 84 98 01 00 00 66 83
> > f8 0a 0f 84
> > [18446744060.832164] RIP �[<ffffffffa02982d9>]
> > cifs_show_options+0xf9/0x480 [cifs]
> > [18446744060.832179] �RSP <ffff880206913dc8>
> > [18446744060.832184] CR2: 0000000000000048
> > [18446744060.832190] BUG: unable to handle kernel NULL pointer
> > dereference at 0000000000000048
> > [18446744060.832199] IP: [<ffffffffa02982d9>]
> > cifs_show_options+0xf9/0x480 [cifs]
> > [18446744060.832211] ---[ end trace d709801030e1a5a5 ]---
> > [18446744060.832217] PGD 233e17067 PUD 233e15067 PMD 0
> > [18446744060.832225] Oops: 0000 [#2] PREEMPT SMP
> > [18446744060.832232] last sysfs file:
> > /sys/devices/system/cpu/sched_smt_power_savings
> > [18446744060.832238] CPU 1
> > [18446744060.832241] Modules linked in: nls_cp437 cifs fbcon tileblit
> > font bitblit softcursor binfmt_misc kvm_intel kvm snd_hda_codec_via
> > snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss nouveau
> > snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi
> > snd_rawmidi snd_seq_midi_event ttm psmouse snd_seq drm_kms_helper
> > snd_timer snd_seq_device serio_raw snd drm asus_atk0110 soundcore
> > snd_page_alloc i2c_algo_bit usbhid hid ahci r8169 mii libahci
> > pata_jmicron
> > [18446744060.832321]
> > [18446744060.832327] Pid: 1356, comm: hald Tainted: G � � �D
> > 2.6.35-rc3 #6 P7P55D-E PRO/System Product Name
> > [18446744060.832334] RIP: 0010:[<ffffffffa02982d9>]
> > [<ffffffffa02982d9>] cifs_show_options+0xf9/0x480 [cifs]
> > [18446744060.832348] RSP: 0018:ffff880234ac3de8 �EFLAGS: 00010246
> > [18446744060.832354] RAX: 0000000000000000 RBX: ffff88020afd0fc0 RCX:
> > 0000000000000006
> > [18446744060.832360] RDX: 0000000000000006 RSI: 0000000000001000 RDI:
> > ffff880232f7f3e5
> > [18446744060.832366] RBP: ffff880234ac3e18 R08: 000000000000fff8 R09:
> > 0000000000000004
> > [18446744060.832372] R10: 0000000000000000 R11: 0000000000000002 R12:
> > ffff880231ad7400
> > [18446744060.832378] R13: ffff8802324d7400 R14: ffff8802324d6b00 R15:
> > 0000000000000000
> > [18446744060.832384] FS: �00007f0b1c325700(0000)
> > GS:ffff880001e20000(0000) knlGS:0000000000000000
> > [18446744060.832390] CS: �0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [18446744060.832396] CR2: 0000000000000048 CR3: 0000000235641000 CR4:
> > 00000000000006e0
> > [18446744060.832401] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> > 0000000000000000
> > [18446744060.832406] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
> > 0000000000000400
> > [18446744060.832413] Process hald (pid: 1356, threadinfo
> > ffff880234ac2000, task ffff880234bc9680)
> > [18446744060.832419] Stack:
> > [18446744060.832423] �ffff880234ac3e18 ffff88020afd0fc0
> > ffff8802324d6b00 ffff8802324d6b60
> > [18446744060.832433] <0> ffffffff8161b470 0000000000000000
> > ffff880234ac3e68 ffffffff81157752
> > [18446744060.832444] <0> ffff8802324d6b00 ffff88023f986000
> > ffff880234ac3e68 ffff88020afd0fc0
> > [18446744060.832458] Call Trace:
> > [18446744060.832467] �[<ffffffff81157752>] show_vfsmnt+0x112/0x150
> > [18446744060.832475] �[<ffffffff8115bc1f>] seq_read+0x25f/0x3f0
> > [18446744060.832484] �[<ffffffff8113c9f5>] vfs_read+0xb5/0x180
> > [18446744060.832492] �[<ffffffff8113de8f>] ? fget_light+0x7f/0xc0
> > [18446744060.832500] �[<ffffffff8113d331>] sys_read+0x51/0x90
> > [18446744060.832510] �[<ffffffff8100b0f2>] system_call_fastpath+0x16/0x1b
> > [18446744060.832515] Code: 00 48 c7 c6 9a 7e 2c a0 48 89 df 31 c0 e8
> > 80 32 ec e0 49 8b 45 28 48 c7 c6 b0 7e 2c a0 4c 8b 78 40 48 89 df 31
> > c0 e8 67 32 ec e0 <41> 0f b7 47 48 66 83 f8 02 0f 84 98 01 00 00 66 83
> > f8 0a 0f 84
> > [18446744060.832634] RIP �[<ffffffffa02982d9>]
> > cifs_show_options+0xf9/0x480 [cifs]
> > [18446744060.832647] �RSP <ffff880234ac3de8>
> > [18446744060.832651] CR2: 0000000000000048
> > [18446744060.832668] ---[ end trace d709801030e1a5a6 ]---
> >

(cc'ing new linux-cifs ML)

Thanks for the bug report. Would you be able to follow the directions
here? That should help us pinpoint the spot where it actually crashed:

http://wiki.samba.org/index.php/LinuxCIFS_troubleshooting#Oopses

Thanks!
--
Jeff Layton <jlayton(a)samba.org>
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From: Jeff Layton on 26 Jun 2010 12:00
On Sat, 26 Jun 2010 22:22:00 +1000
Andrew Hendry <andrew.hendry(a)gmail.com> wrote:

> I have turned on cifs debug to try to catch it if happens again.
>
> (gdb) list *(cifs_show_options+0xf9)
> 0x309 is in cifs_show_options (fs/cifs/cifsfs.c:336).
> 331 static void
> 332 cifs_show_address(struct seq_file *s, struct TCP_Server_Info *server)
> 333 {
> 334 seq_printf(s, ",addr=");
> 335
> 336 switch (server->addr.sockAddr.sin_family) {
> 337 case AF_INET:
> 338 seq_printf(s, "%pI4", &server->addr.sockAddr.sin_addr.s_addr);
> 339 break;
> 340 case AF_INET6:
>
>
>
>

Thanks, that helps. It looks like the "server" pointer in that function
was NULL or something close to it. Those should be properly refcounted
nowadays and that hasn't changed in quite a while. This function only
gets called from one place -- cifs_show_options. So something was
reading /proc/self/mountinfo and this pointer got zeroed out. Maybe
this raced with an unmount and the memory was recycled? Doesn't seem
like that ought to be possible though (I think vfsmount references are
held for each of these calls).

--
Jeff Layton <jlayton(a)samba.org>
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Prev: (stupid) how to specify the root-device via kernel parameters
Next: [PATCH 2/2] bmp085: Add interface documentation and link to datasheet.