Re: [edk2-devel] [PATCH 2/2] MdeModulePkg/Bus/Ata/AtaAtapiPassThru: Fix UNUSED_VALUE Coverity issue

[Ranbir Singh <rsingh@ventanamicro.com>]

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I mentioned similar approach in
https://bugzilla.tianocore.org/show_bug.cgi?id=4204#c1

Let me know if I should update the patch as Hao proposed -

if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Set drive parameters Fail, Status = %r\n",
Status));
    continue;
  }

On Thu, Jun 8, 2023 at 12:25 PM Wu, Hao A <hao.a.wu@intel.com> wrote:

> > -----Original Message-----
> > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ard
> > Biesheuvel
> > Sent: Monday, June 5, 2023 4:32 PM
> > To: Ranbir Singh <rsingh@ventanamicro.com>
> > Cc: devel@edk2.groups.io; pedro.falcato@gmail.com; Wu, Hao A
> > <hao.a.wu@intel.com>; Ni, Ray <ray.ni@intel.com>
> > Subject: Re: [edk2-devel] [PATCH 2/2]
> > MdeModulePkg/Bus/Ata/AtaAtapiPassThru: Fix UNUSED_VALUE Coverity
> > issue
> >
> > On Mon, 5 Jun 2023 at 10:10, Ranbir Singh <rsingh@ventanamicro.com>
> > wrote:
> > >
> > > I counted myself as not the right person to decide what all to do if
> Status is
> > not successful. Adding the DEBUG statement from the Coverity aspect
> > doesn't count as a fix as RELEASE mode behavior remains the same.
> > >
> > > In the comments / description, I already mentioned - Assuming, this
> non-
> > usage is deliberate, so as such I did not intend to hide anything - and
> left it in
> > the status quo.
> > >
> > > The patch proposed may not be appropriate, but should now give a
> > thinking point to active module developers / owners / maintainers if they
> > indeed feel that there is a bug here and it needs to be fixed.
> > >
> >
> > Thanks - I agree that it is a good thing that people are aware of this
> now.
>
>
> Judging from the context in DetectAndConfigIdeDevice(), I think a fix can
> be:
>
>   Status = SetDriveParameters (Instance, IdeChannel, IdeDevice,
> &DriveParameters, NULL);
>   if (EFI_ERROR (Status)) {
>     DEBUG ((DEBUG_ERROR, "Set drive parameters Fail, Status = %r\n",
> Status));
>     continue;
>   }
>
> But I do not have the device and platform environment to verify the change.
> Really sorry for this. I am not sure on the potential risk of making this
> change without at least some kind of 'no-break' tests.
>
> Best Regards,
> Hao Wu
>
>
> >
> > > On Mon, Jun 5, 2023 at 4:33 AM Ard Biesheuvel <ardb@kernel.org> wrote:
> > >>
> > >> On Sat, 3 Jun 2023 at 18:04, Pedro Falcato <pedro.falcato@gmail.com>
> > wrote:
> > >> >
> > >> > On Fri, Jun 2, 2023 at 8:42 PM Ranbir Singh <
> rsingh@ventanamicro.com>
> > wrote:
> > >> > >
> > >> > > From: Ranbir Singh <Ranbir.Singh3@Dell.com>
> > >> > >
> > >> > > The return value stored in Status after call to SetDriveParameters
> > >> > > is not made of any use thereafter and hence it remains as UNUSED.
> > >> > > Assuming, this non-usage is deliberate, the storage in Status can
> be
> > >> > > done away with.
> > >> > >
> > >> > > Cc: Hao A Wu <hao.a.wu@intel.com>
> > >> > > Cc: Ray Ni <ray.ni@intel.com>
> > >> > > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4204
> > >> > > Signed-off-by: Ranbir Singh <Ranbir.Singh3@Dell.com>
> > >> > > ---
> > >> > >  MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c | 2 +-
> > >> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >> > >
> > >> > > diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c
> > b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c
> > >> > > index 75403886e44a..c6d637afa989 100644
> > >> > > --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c
> > >> > > +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/IdeMode.c
> > >> > > @@ -2555,7 +2555,7 @@ DetectAndConfigIdeDevice (
> > >> > >        DriveParameters.Heads          =
> (UINT8)(((ATA5_IDENTIFY_DATA
> > *)(&Buffer.AtaData))->heads - 1);
> > >> > >        DriveParameters.MultipleSector =
> (UINT8)((ATA5_IDENTIFY_DATA
> > *)(&Buffer.AtaData))->multi_sector_cmd_max_sct_cnt;
> > >> > >
> > >> > > -      Status = SetDriveParameters (Instance, IdeChannel,
> IdeDevice,
> > &DriveParameters, NULL);
> > >> > > +      SetDriveParameters (Instance, IdeChannel, IdeDevice,
> > &DriveParameters, NULL);
> > >> >
> > >> > I'm /fairly/ sure this is wrong and that you need to use Status.
> > >> >
> > >>
> > >> Yeah, removing the assignment fixes the coverity warning, but now you
> > >> are hiding a bug instead of fixing it.
> > >>
> > >> SetDriveParameters () can apparently fail, and this is being ignored.
> > >> At the very least, we should emit a diagnostic here in DEBUG mode to
> > >> log this. E.g.,
> > >>
> > >> DEBUG ((DEBUG_WARN, "%a: SetDriveParameters () failed - %r\n",
> > >> __func__, Status));
> >
> >
> > 
> >
>
>

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