[Devel] Re: [SCSI] 3w-9xxx: kmap_atomic in twa_scsiop_execute_scsi

[Vasily Averin]

Adam Radford wrote:
> Vasily,
> 
> I actually didn't forget this.  I think it isn't needed.  The reason
> being
> that in scsi.c: scsi_dispatch_command(), where hostt->queuecommand() is
> called,
> there is a spin_lock_irqsave()/spin_unlock_irqrestore() wrapper in
> there, disabling
> interrupts.

Adam,

I'm agree that queuecommand() executed with disabled interrupts. However
twa_scsiop_execute_scsi() can be called not only from queuecommand. For example,

twa_interrupts (note: with _enabled_ interrupts)
   twa_aen_read_queue
     twa_scsiop_execute_scsi

or

twa_chrdev_ioctl
   twa_reset_device_extension
      twa_reset_sequence
         twa_aen_drain_queue
            twa_scsiop_execute_scsi

Thank you,
	Vasily Averin

SWsoft Virtuozzo/OpenVZ Linux kernel team

> -----Original Message-----
> From: Vasily Averin [mailto:vvs at sw.ru] 
> Sent: Sunday, June 04, 2006 1:49 AM
> To: adam radford; linuxraid
> Cc: James Bottomley; Linux Kernel Mailing List;
> linux-scsi at vger.kernel.org; devel at openvz.org; Andrew Morton
> Subject: [SCSI] 3w-9xxx: kmap_atomic in twa_scsiop_execute_scsi
> 
> Hello Adam,
> 
> you have fixed recently potential memory corruption, kmap_atomic issue
> in 3w-9xxx driver, however it seems for me you have forgotten to fix the
> same issue in yet another similar place, in twa_scsiop_execute_scsi()
> function.
> 
> Signed-off-by: Vasily Averin <vvs at sw.ru>
> 
> Thank you,
> 	Vasily Averin
> 
> SWsoft Virtuozzo/OpenVZ Linux kernel team
> 
>