Re: [crash] BUG: unable to handle kernel NULL pointer dereference at 0000000000000370

Ingo Molnar wrote:

* Larry Finger [off-list ref] wrote:

quoted

Ingo Molnar wrote:

quoted

* Ian Schram [off-list ref] wrote:

quoted

I was looking at this out of interest, but I'm in no way familiar 
with the code.

thanks Ian for the patch, i'll test it.

Note that it was whitespace damaged, find below a tidied up version of  
the patch that i've applied to tip/out-of-tree.

	Ingo

This patch may be needed to fix error handling in the hw_sim code, but 
I get the crash even with that code disabled. I'm currently bisecting 
to find the culprit.

ok. I just reactivated CONFIG_MAC80211_HWSIM, applied Ian's fix and the 
crash went away:

 calling  iwl4965_init+0x0/0x6c
 iwl4965: Intel(R) Wireless WiFi Link 4965AGN driver for Linux, 1.3.27kd
 iwl4965: Copyright(c) 2003-2008 Intel Corporation
 initcall iwl4965_init+0x0/0x6c returned 0 after 10 msecs
 calling  init_mac80211_hwsim+0x0/0x31c
 mac80211_hwsim: Initializing radio 0
 PM: Adding info for No Bus:hwsim0
 PM: Adding info for No Bus:phy0
 PM: Adding info for No Bus:wmaster0
 phy0: Failed to select rate control algorithm
 phy0: Failed to initialize rate control algorithm
 PM: Removing info for No Bus:wmaster0
 PM: Removing info for No Bus:phy0
 mac80211_hwsim: ieee80211_register_hw failed (-2)
 PM: Removing info for No Bus:hwsim0
 initcall init_mac80211_hwsim+0x0/0x31c returned -2 after 58 msecs
 initcall init_mac80211_hwsim+0x0/0x31c returned with error code -2
 calling  dmfe_init_module+0x0/0xea
 dmfe: Davicom DM9xxx net driver, version 1.36.4 (2002-01-17)
 initcall dmfe_init_module+0x0/0xea returned 0 after 5 msecs

So at least as far as the init_mac80211_hwsim() deinit crash goes:

Tested-by: Ingo Molnar <redacted>

Yes, I'm chasing a distinct bug. The header for mine is

Jul 21 12:19:37 larrylap kernel: kernel BUG at net/core/dev.c:1328!
Jul 21 12:19:37 larrylap kernel: invalid opcode: 0000 [1] SMP
Jul 21 12:19:37 larrylap kernel: CPU 0
Jul 21 12:19:37 larrylap kernel: Modules linked in: af_packet rfkill_input nfs 
lockd nfs_acl sunrpc cpufreq_conservative cpu
freq_userspace cpufreq_powersave powernow_k8 fuse loop dm_mod arc4 ecb 
crypto_blkcipher b43 firmware_class rfkill mac80211 c
fg80211 snd_hda_intel snd_pcm snd_timer led_class snd k8temp input_polldev 
sr_mod soundcore button battery hwmon cdrom force
deth ac serio_raw ssb snd_page_alloc sg ehci_hcd sd_mod ohci_hcd usbcore edd fan 
thermal processor ext3 mbcache jbd pata_amd
  ahci libata scsi_mod dock
Jul 21 12:19:37 larrylap kernel: Pid: 2057, comm: b43 Not tainted 
2.6.26-Linus-git-05253-g14b395e #1
Jul 21 12:19:37 larrylap kernel: RIP: 0010:[<ffffffff8039ec4d>] 
[<ffffffff8039ec4d>] __netif_schedule+0x12/0x75
Jul 21 12:19:37 larrylap kernel: RSP: 0000:ffff8800b9ae1de0  EFLAGS: 00010246

With an invalid opcode, mine is likely due to stack corruption.

Larry
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html