Messages in this thread | | | Date | Thu, 3 Jan 2002 21:06:53 +0100 | From | Jens Axboe <> | Subject | Re: bug in IBM ServeRAID driver? |
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On Thu, Jan 03 2002, petter wahlman wrote: > > While looking through linux-2.4.18pre1/drivers/scsi/ips.c I noticed that > a spin_lock_irq is held while doing a possibly blocking operation. > Can't this code livelock on SMP if datasize is set? > > linux-2.4.18pre1/drivers/scsi/ips.c > > 1778 /* reobtain the lock */ > 1779 spin_lock_irq(&io_request_lock); > 1780 > 1781 /* command finished -- copy back */ > 1782 user_area = *((char **) &SC->cmnd[4]); > 1783 kern_area = ha->ioctl_data; > 1784 datasize = *((u_int32_t *) &SC->cmnd[8]); > 1785 > 1786 if (datasize) { > 1787 if (copy_to_user(user_area, kern_area, datasize) > 0) { > 1788 DEBUG_VAR(1, "(%s%d) passthru failed - unable to > copy out user data", > 1789 ips_name, ha->host_num); > > > I am not subscribed to this list, so please CC me.
Yup, that's surely a nasty bug.
-- Jens Axboe
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