Re: BUG: unable to handle kernel NULL pointer dereference, i915_gem_object_move_to_active

[Nils Radtke <Nils.Radtke@Think-Future.de>]

  Hi Jan,

It's been happening here since first kernel on this box, when "the other OS" 
had to leave, approx. end of 2008.

*ubuntu didn't help either, so far.

A kernel NULL ptr deref looks like a serious thing, at least to me. 
Unfortunately, I'm not yet that deep into kernel code that I myself 
could do that easily.. Maybe someone more apt in this regard 
can help us out here?

Cheers,

  Nils

On mer 2010-05-05 @ 11-46-11 +0200, Jan Evert van Grootheest (SDG) wrote: 
# Hi Nils,
# 
# Op 05-05-10 00:22, Nils Radtke schreef:
# >   Hi,
# >
# >It happens quite often that X crashes for unknown reasons but this time
# It appears the same is (was) happening to my wifes laptop. But I've
# never been able to find a reason for it, nor a BUG or WARN. And the
# same logoff and firefox crashes that you mention, although it has
# Gnome on it instead of KDE.
# That was going on with Ubuntu Karmic installed (using standard
# Ubuntu 2.6.31 kernel). Yesterday I decided (since she'd be gone for
# the whole day) to upgrade to Lucid. I'll have to wait and see
# whether that still happens. I have seen already that on some boots
# the wireless is not stable (i.e. the connection gets dropped after a
# few seconds and re-negotiated), but I guess that's not related.
# 
# As for the hw, it's an Acer Aspire 3650: Celeron, ATI SB400, ATI
# based graphics (using the radeon driver) and Atheros based wireless
# (using ath5k). So it seems that most of the hw differs except for
# the wireless.
# 
# -- Jan Evert
# 
# >there it's left us a note, this BUG:
# >
# >BUG: unable to handle kernel NULL pointer dereference at 000001e4
# >IP: [<c134ddbc>] i915_gem_object_move_to_active+0x1c/0xa0
# >*pde = 00000000
# >Oops: 0000 [#4] PREEMPT
# >last sysfs file: /sys/devices/pci0000:00/0000:00:1c.1/0000:04:00.0/net/wlan0/wireless/link
# >Modules linked in: wlan_scan_sta ath_rate_sample ath_pci ath_hal option usbserial usb_storage snd_usb_audio snd_usb_lib snd_seq_midi snd_rawmidi uvcvideo wlan_ccmp video1394 raw1394 dv1394 firewire_ohci firewire_core wlan ohci1394 tg3 libphy ieee1394 [last unloaded: ath_hal]
# >
# >Pid: 3328, comm: Xorg Tainted: G      D    2.6.33 #1 Columbia                       /Extensa 5220
# >EIP: 0060:[<c134ddbc>] EFLAGS: 00213282 CPU: 0
# >EIP is at i915_gem_object_move_to_active+0x1c/0xa0
# >EAX: 00000000 EBX: c6679450 ECX: c679fd50 EDX: 00b10a13
# >ESI: 00000000 EDI: 00000000 EBP: 00b10a13 ESP: f51c1cb0
# >  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
# >Process Xorg (pid: 3328, ti=f51c0000 task=f6be5bf0 task.ti=f51c0000)
# >Stack:
# >  c6679450 00000004 00000000 c679fd50 c134e83f 00000002 c17d42ab c16e3b29
# ><0>  c17d71ee 00b10a13 00000004 f7395800 f7318000 f7318e10 c1326450 f7318df8
# ><0>  f6baff20 00b10a13 f7318de8 f7318e10 f7318000 00000004 00000001 f7395800
# >Call Trace:
# >  [<c134e83f>] ? i915_add_request+0x25f/0x370
# >  [<c1326450>] ? agp_flush_chipset+0x10/0x20
# >  [<c1352d55>] ? i915_gem_do_execbuffer+0x1325/0x13a0
# >  [<c102e087>] ? check_preempt_wakeup+0x87/0x160
# >  [<c13530ae>] ? i915_gem_execbuffer+0xee/0x4b0
# >  [<c13531fb>] ? i915_gem_execbuffer+0x23b/0x4b0
# >  [<c1334056>] ? drm_ioctl+0x186/0x380
# >  [<c1352fc0>] ? i915_gem_execbuffer+0x0/0x4b0
# >  [<c10d79dd>] ? do_sync_read+0xad/0xf0
# >  [<c1333ed0>] ? drm_ioctl+0x0/0x380
# >  [<c10e5fcb>] ? vfs_ioctl+0x2b/0xa0
# >  [<c10e61a3>] ? do_vfs_ioctl+0x73/0x5f0
# >  [<c1038229>] ? do_setitimer+0xd9/0x220
# >  [<c1058a93>] ? ktime_get_ts+0xe3/0x100
# >  [<c104e1e0>] ? posix_ktime_get_ts+0x0/0x10
# >  [<c10e6786>] ? sys_ioctl+0x66/0x70
# >  [<c1002c8c>] ? sysenter_do_call+0x12/0x22
# >Code: 8a 8d b4 26 00 00 00 00 8d bc 27 00 00 00 00 83 ec 10 89 c1 89 6c 24 0c 89 d5 89 1c 24 89 74 24 04 89 7c 24 08 8b 40 08 8b 71 50<8b>  b8 e4 01 00 00 8b 46 20 85 c0 74 5f 89 e1 81 e1 00 e0 ff ff
# >EIP: [<c134ddbc>] i915_gem_object_move_to_active+0x1c/0xa0 SS:ESP 0068:f51c1cb0
# >CR2: 00000000000001e4
# >---[ end trace 13931f32db9a26c3 ]---
# >
# >
# >- Is there any particular meaning for "last sysfs file" shown? I mean, could there
# >   be some link between the crash and "last sysfs file"?
# >
# >- X crashing happens actually a lot on this specific notebook. If it's not X crashing,
# >   then unmotivated kde log-offs or frequent firefox crashes contribute their share.
# >   It's most probably not faulty RAM, it's new, it's been tested thoroughly.
# >
# >
# >Thanks for some answers,
# >
# >   Nils
# >
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# >
# 

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