Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
MIME-Version: 1.0
References: <20220217153842.3252424-1-trix@redhat.com> <51018469-3bab-e56d-7407-b16170b5d74c@amd.com>
In-Reply-To: <51018469-3bab-e56d-7407-b16170b5d74c@amd.com>
From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Thu, 17 Feb 2022 11:16:14 -0500
Message-ID: <CADnq5_OGEURo76mzc4Sb2Jar465Xt4vkSMECDi5jCMH332zUAg@mail.gmail.com>
Subject: Re: [PATCH] drm/amdgpu: fix amdgpu_ras_block_late_init error handler
To:     Luben Tuikov <luben.tuikov@amd.com>
Cc:     Tom Rix <trix@redhat.com>,
        "Deucher, Alexander" <alexander.deucher@amd.com>,
        Christian Koenig <christian.koenig@amd.com>,
        xinhui pan <Xinhui.Pan@amd.com>,
        Dave Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Hawking Zhang <Hawking.Zhang@amd.com>,
        John Clements <john.clements@amd.com>,
        Tao Zhou <tao.zhou1@amd.com>,
        "Chai, Thomas" <YiPeng.Chai@amd.com>,
        "Stanley.Yang" <Stanley.Yang@amd.com>,
        Dennis Li <Dennis.Li@amd.com>,
        "Joshi, Mukul" <mukul.joshi@amd.com>,
        Nirmoy Das <nirmoy.das@amd.com>, llvm@lists.linux.dev,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>,
        amd-gfx list <amd-gfx@lists.freedesktop.org>,
        LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Applied.  Thanks!

Alex

On Thu, Feb 17, 2022 at 10:57 AM Luben Tuikov <luben.tuikov@amd.com> wrote:
>
> Thanks for catching this.
>
> Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
>
> Regards,
> Luben
>
> On 2022-02-17 10:38, trix@redhat.com wrote:
> > From: Tom Rix <trix@redhat.com>
> >
> > Clang build fails with
> > amdgpu_ras.c:2416:7: error: variable 'ras_obj' is used uninitialized
> >   whenever 'if' condition is true
> >   if (adev->in_suspend || amdgpu_in_reset(adev)) {
> >   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > amdgpu_ras.c:2453:6: note: uninitialized use occurs here
> >  if (ras_obj->ras_cb)
> >      ^~~~~~~
> >
> > There is a logic error in the error handler's labels.
> > ex/ The sysfs: is the last goto label in the normal code but
> > is the middle of error handler.  Rework the error handler.
> >
> > cleanup: is the first error, so it's handler should be last.
> >
> > interrupt: is the second error, it's handler is next.  interrupt:
> > handles the failure of amdgpu_ras_interrupt_add_hander() by
> > calling amdgpu_ras_interrupt_remove_handler().  This is wrong,
> > remove() assumes the interrupt has been setup, not torn down by
> > add().  Change the goto label to cleanup.
> >
> > sysfs is the last error, it's handler should be first.  sysfs:
> > handles the failure of amdgpu_ras_sysfs_create() by calling
> > amdgpu_ras_sysfs_remove().  But when the create() fails there
> > is nothing added so there is nothing to remove.  This error
> > handler is not needed. Remove the error handler and change
> > goto label to interrupt.
> >
> > Fixes: b293e891b057 ("drm/amdgpu: add helper function to do common ras_late_init/fini (v3)")
> > Signed-off-by: Tom Rix <trix@redhat.com>
> > ---
> >  drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 11 +++++------
> >  1 file changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
> > index b5cd21cb6e58..c5c8a666110f 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
> > @@ -2432,12 +2432,12 @@ int amdgpu_ras_block_late_init(struct amdgpu_device *adev,
> >       if (ras_obj->ras_cb) {
> >               r = amdgpu_ras_interrupt_add_handler(adev, ras_block);
> >               if (r)
> > -                     goto interrupt;
> > +                     goto cleanup;
> >       }
> >
> >       r = amdgpu_ras_sysfs_create(adev, ras_block);
> >       if (r)
> > -             goto sysfs;
> > +             goto interrupt;
> >
> >       /* Those are the cached values at init.
> >        */
> > @@ -2447,12 +2447,11 @@ int amdgpu_ras_block_late_init(struct amdgpu_device *adev,
> >       }
> >
> >       return 0;
> > -cleanup:
> > -     amdgpu_ras_sysfs_remove(adev, ras_block);
> > -sysfs:
> > +
> > +interrupt:
> >       if (ras_obj->ras_cb)
> >               amdgpu_ras_interrupt_remove_handler(adev, ras_block);
> > -interrupt:
> > +cleanup:
> >       amdgpu_ras_feature_enable(adev, ras_block, 0);
> >       return r;
> >  }
>