Re: iwlagn driver segfault in 2.6.28-rc3

["Carlos R. Mafra" <crmafra2@gmail.com>]

I just got (another) one of this too.

The wireless connection suddenly lost the AP and I was waiting
for ifplugd to reconnect to it again automatically, as it always
does.

After waiting for one or two minutes I decided to 'modprobe -r
iwlagn' but this command never returned (it got stuck). 

Then I looked at the end of dmesg and found this:

general protection fault: 0000 [#1] SMP 
last sysfs file: /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
CPU 1 
Modules linked in: nls_iso8859_1 nls_cp437 vfat fat usb_storage xt_comment xt_policy xt_tcpmss xt_pkttype xt_owner xt_NFQUEUE xt_NFLOG xt_multiport xt_MARK xt_mark xt_mac xt_limit xt_length xt_iprange xt_hashlimit xt_dscp xt_dccp xt_CLASSIFY snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss nvram ohci1394 ieee1394 snd_hda_intel uvcvideo snd_pcm sg sky2 i2c_i801 sr_mod iwlagn compat_ioctl32 snd_timer evdev videodev snd_page_alloc v4l1_compat snd_hwdep ata_piix ahci libata sd_mod scsi_mod uhci_hcd ohci_hcd ehci_hcd usbcore [last unloaded: scsi_wait_scan]
Pid: 3163, comm: ifplugd Not tainted 2.6.28-rc4-keypress-00322-g58e20d8 #14
RIP: 0010:[<ffffffff803d844b>]  [<ffffffff803d844b>] iwl_eeprom_query16+0xb/0x20
RSP: 0018:ffff88007b631a88  EFLAGS: 00010092
RAX: 7fff88007dfd5400 RBX: ffff88007d81a000 RCX: 00000000800600f0
RDX: 0000000000000cfc RSI: 0000000000000090 RDI: ffff88007dcc1940
RBP: ffff88007b631a88 R08: 0000000000000002 R09: ffff88007b631a5c
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000080006
R13: ffff88007dcc1940 R14: ffff88007dcc29f8 R15: ffff88007d81a740
FS:  00007f7f93ef16f0(0000) GS:ffff88007f0686c0(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00002ad88fdfd000 CR3: 000000007d935000 CR4: 00000000000006a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process ifplugd (pid: 3163, threadinfo ffff88007b630000, task ffff88007b5ba980)
Stack:
 ffff88007b631af8 ffffffffa0108526 ffff88007b631af8 ffffffffa00f3aaf
 0000000000000000 ffff88007dcc2328 0000000000000292 0000000000000000
 0143000000000000 ffff88007d81a000 ffff88007dcc1940 ffff88007dcc2328
Call Trace:
 [<ffffffffa0108526>] iwl4965_nic_config+0xa6/0x380 [iwlagn]
 [<ffffffffa00f3aaf>] ? iwl4965_set_pwr_src+0x1cf/0x3d0 [iwlagn]
 [<ffffffff803d5a9b>] iwl_hw_nic_init+0x11b/0x1d0
 [<ffffffffa00fbe17>] __iwl4965_up+0x1a7/0x720 [iwlagn]
 [<ffffffffa00fd0c8>] iwl4965_mac_start+0xd38/0x1570 [iwlagn]
 [<ffffffff8022d365>] ? __wake_up_sync+0x55/0x70
 [<ffffffff8043000f>] ? sock_def_readable+0x6f/0x80
 [<ffffffff8049b893>] ? unix_dgram_sendmsg+0x463/0x4f0
 [<ffffffff804b5cf8>] ieee80211_open+0x328/0x830
 [<ffffffff8042bf5b>] ? sock_sendmsg+0xdb/0xf0
 [<ffffffff8043cba4>] dev_open+0x64/0xc0
 [<ffffffff8043ba71>] dev_change_flags+0x91/0x1b0
 [<ffffffff8047fde3>] devinet_ioctl+0x5b3/0x750
 [<ffffffff8048096d>] inet_ioctl+0x6d/0x90
 [<ffffffff8042c4d5>] sock_ioctl+0xc5/0x240
 [<ffffffff802a60f1>] vfs_ioctl+0x31/0x90
 [<ffffffff802a647b>] do_vfs_ioctl+0x32b/0x460
 [<ffffffff802a65fa>] sys_ioctl+0x4a/0x80
 [<ffffffff8020c1fb>] system_call_fastpath+0x16/0x1b
Code: 48 8b 47 18 55 48 89 e5 48 8b 40 18 48 8b 00 ff 90 00 01 00 00 c9 c3 66 0f 1f 84 00 00 00 00 00 48 8b 87 98 22 01 00 55 48 89 e5 <0f> b6 54 06 01 0f b6 04 30 c9 c1 e2 08 09 d0 0f b7 c0 c3 66 90 
RIP  [<ffffffff803d844b>] iwl_eeprom_query16+0xb/0x20
 RSP <ffff88007b631a88>
---[ end trace 28eaede31d178563 ]---


I tried to reboot but it got stuck too, so I had to SysRq+b.

>From now on I will apply Reinette's patch and wait for it to
happen again (but it seldom happens).