Re: [bug] ata subsystem related crash with latest -git

Jens Axboe
2007-10-17T19:25:25Z

On Wed, Oct 17 2007, Ingo Molnar wrote:
>
> * Jens Axboe <jens.axboe@oracle.com> wrote:
>
> > On Wed, Oct 17 2007, Ingo Molnar wrote:
> > >
> > > btw., i get the following build warning:
> > >
> > > drivers/scsi/scsi_lib.c: In function 'scsi_free_sgtable':
> > > drivers/scsi/scsi_lib.c:708: warning: 'index' may be used uninitialized in this function
> > > drivers/scsi/scsi_lib.c:708: note: 'index' was declared here
> > > drivers/scsi/scsi_lib.c:708: warning: 'index' may be used uninitialized in this function
> > > drivers/scsi/scsi_lib.c:708: note: 'index' was declared here
> > > drivers/scsi/scsi_lib.c: In function 'scsi_alloc_sgtable':
> > > drivers/scsi/scsi_lib.c:708: warning: 'index' may be used uninitialized in this function
> > > drivers/scsi/scsi_lib.c:708: note: 'index' was declared here
> > >
> > > not sure it matters.
> >
> > Hmm, I don't see them here (gcc 4.2.1). Must be the BUG(), does it go
> > away if you add a index = -1 in the default: case? Just to be
> > absolutely sure...
>
> well if i initialize the variable then of course the warning goes away
> :)

Just making 100% sure that was the missing place, I try not to take
anything for granted with crazy bugs like this :-)
>
> NOTE: i get the same warning even without the BUG_ON() patch, and
> without your other fix patch as well. I'm using gcc 4.2.2. (Do you get
> the warning if you pick up the config i sent you earlier today?)

Let me check... Yep, I do!

--
Jens Axboe