Re: [PATCH]drivers/ata/libata-eh.c:1509 unneeded memset()

[René Bolldorf]

On 01/11/10 20:41, Marc Bejarano wrote:
> and once more in plain text.  (sorry vger)
>
> 2010/1/11 Marc Bejarano<beej@xxxxxxxx>:
> > oops.  seems that GMANE's reply function only goes to a single "newsgroup".
> >   original recipients re-added.
> > marc
> > ----
> > From: Marc Bejarano<beej<at>  beej.org>
> > Subject: Re: [PATCH]drivers/ata/libata-eh.c:1509 unneeded memset()
> > Newsgroups: gmane.linux.scsi
> > Date: 2010-01-08 22:21:09 GMT (2 days, 20 hours and 40 minutes ago)
> >
> > René Bolldorf<xsecute<at>  googlemail.com>  writes:
> > > On 01/08/10 16:28, James Bottomley wrote:
> > > > On Thu, 2010-01-07 at 14:15 -0500, Jeff Garzik wrote:
> > > > > On 12/30/2009 05:59 PM, René Bolldorf wrote:
> > > > > > We don't need this .
> >
> > > > > > - /* FIXME: is this needed? */
> > > > > > - memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);
> > > > >
> > > > > I need a little bit more detail than an unqualified statement...  Did
> > > > > you audit all paths leading to this code point?
> >
> > > > But one also here:
> > > >
> > > > u8 *sense_buffer = dev->link->ap->sector_buf;
> > > > [...]
> > > > err_mask = atapi_eh_request_sense(dev, sense_buffer, sense_key);
> > > >
> > > > Which doesn't look OK because it looks like the sector_buf isn't cleared
> > > > (and it is reused).
> > > >
> > > > James
> > >
> > > Thank's, you're right. I have overseen this, sry for that.
> >
> > René: perhaps you'd like to submit a patch that substitutes FIXME comment
> > for one that explains why the memset is needed, crediting James in the
> > description?  we may as well gain something permanent from this discussion
> > that you started :)
> >
> > cheers,
> > marc
> >
> > --
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> >
> > ----

I hope that's good enough explained :-).

Best regards
René

--- ./drivers/ata/libata-eh.c   2010-01-07 23:21:23.622464012 +0100
+++ ./drivers/ata/libata-eh.c   2010-01-11 21:11:19.869092897 +0100
@@ -1505,7 +1505,10 @@ static unsigned int atapi_eh_request_sen

        DPRINTK("ATAPI request sense\n");

-       /* FIXME: is this needed? */
+       /* make sure sense_buf is cleared then atapi_eh_request_sense is 
called.
+        * (to make sure nothing get's reused.)
+        * thanks to James Bottomley
+        */
        memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);

        /* initialize sense_buf with the error register,
--
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