Messages in this thread | | | From | Sitsofe Wheeler <> | Subject | Re: [BUG] unable to handle kernel paging request in next-20080516 | Date | Fri, 23 May 2008 20:34:25 +0100 |
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<posted & mailed>
James Bottomley wrote:
> Actually, I think this is a very subtle bug; what I think is happening > is that after Hannes sysfs changes, we now add scsi_bus_type to the > target device. However, scsi_bus_uevent() unconditionally casts from > dev to a struct scsi_device and then looks at the type entry. My theory > is that in this particular config going from struct scsi_target to > struct device and back to struct scsi_device actually tips us over into > unmapped space for the -> type deref. > > Hopefully this should fix it by checking the device type before doing > the deref.
This fixed the problem for me (it was horribly intermittant but I've done 10+ consecutive reboots without seeing an oopos). I changed the patch to printk everytime the condition was hit and it seems to happen twice per PATA device - once after each scsi?: pata_via message and then again after each scsi 0:0:0:0: Direct-Accesss ATA DISKID etc : 0 ANSI: 5 .
The thing I don't understand about your explanation is that it sounds like the device struct is being round-tripped (but is just being cast to different things along the way). If this is the case why would this problem ever arise? Surely if it is really a struct scsi_device underneath there should be no problem?
-- Sitsofe | http://sucs.org/~sits/
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