Now that we have infrastructure for reporting errors, let's add two
checks, which will make sure slice can be actually decoded.
Signed-off-by: Jernej Skrabec <[email protected]>
---
drivers/staging/media/sunxi/cedrus/cedrus_h265.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
index cfde4ccf6011..99020b9f9ff8 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
@@ -435,9 +435,17 @@ static int cedrus_h265_setup(struct cedrus_ctx *ctx, struct cedrus_run *run)
* instead of start of slice data. Padding is 8 bits at most (one bit set to 1 and
* at most seven bits set to 0), so we have to inspect only one byte before slice data.
*/
+
+ if (slice_params->data_byte_offset == 0)
+ return -EOPNOTSUPP;
+
padding = (u8 *)vb2_plane_vaddr(&run->src->vb2_buf, 0) +
slice_params->data_byte_offset - 1;
+ /* at least one bit must be set in that byte */
+ if (*padding == 0)
+ return -EINVAL;
+
for (count = 0; count < 8; count++)
if (*padding & (1 << count))
break;
--
2.36.1
On Mon, Jun 20, 2022 at 07:55:15PM +0200, Jernej Skrabec wrote:
> Now that we have infrastructure for reporting errors, let's add two
> checks, which will make sure slice can be actually decoded.
>
> Signed-off-by: Jernej Skrabec <[email protected]>
> ---
> drivers/staging/media/sunxi/cedrus/cedrus_h265.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> index cfde4ccf6011..99020b9f9ff8 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
Now that you've allowed setup to fail, I would suggest
to have some documentation/comments on struct cedrus_dec_ops,
to set the expectation/rules for each ops, including the
call paths for each operation, which of them are allowed to sleep,
etc.
> @@ -435,9 +435,17 @@ static int cedrus_h265_setup(struct cedrus_ctx *ctx, struct cedrus_run *run)
> * instead of start of slice data. Padding is 8 bits at most (one bit set to 1 and
> * at most seven bits set to 0), so we have to inspect only one byte before slice data.
> */
> +
> + if (slice_params->data_byte_offset == 0)
> + return -EOPNOTSUPP;
> +
AFAICS, cedrus_h265_setup is called from .device_run.
We've been discussing control validation before, and I think the
ideal place to do that is v4l2_ctrl_ops.s_ctrl, if that's
at all possible.
Driver's mem2mem device_run are executed in the context
of a work_struct and the failure won't really get reported
up the stack.
> padding = (u8 *)vb2_plane_vaddr(&run->src->vb2_buf, 0) +
> slice_params->data_byte_offset - 1;
>
> + /* at least one bit must be set in that byte */
> + if (*padding == 0)
> + return -EINVAL;
> +
Maybe this is something to check at cedrus_buf_prepare(),
when the buffer is queued?
Thanks,
Ezequiel
> for (count = 0; count < 8; count++)
> if (*padding & (1 << count))
> break;
> --
> 2.36.1
>
Hi Ezequiel.
Dne ponedeljek, 11. julij 2022 ob 23:31:11 CEST je Ezequiel Garcia napisal(a):
> On Mon, Jun 20, 2022 at 07:55:15PM +0200, Jernej Skrabec wrote:
> > Now that we have infrastructure for reporting errors, let's add two
> > checks, which will make sure slice can be actually decoded.
> >
> > Signed-off-by: Jernej Skrabec <[email protected]>
> > ---
> >
> > drivers/staging/media/sunxi/cedrus/cedrus_h265.c | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> > b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c index
> > cfde4ccf6011..99020b9f9ff8 100644
> > --- a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
>
> Now that you've allowed setup to fail, I would suggest
> to have some documentation/comments on struct cedrus_dec_ops,
> to set the expectation/rules for each ops, including the
> call paths for each operation, which of them are allowed to sleep,
> etc.
Documentation can be always added, but it should be separate patch.
>
> > @@ -435,9 +435,17 @@ static int cedrus_h265_setup(struct cedrus_ctx *ctx,
> > struct cedrus_run *run)>
> > * instead of start of slice data. Padding is 8 bits at most (one
bit
> > set to 1 and * at most seven bits set to 0), so we have to
inspect
> > only one byte before slice data. */
> >
> > +
> > + if (slice_params->data_byte_offset == 0)
> > + return -EOPNOTSUPP;
> > +
>
> AFAICS, cedrus_h265_setup is called from .device_run.
> We've been discussing control validation before, and I think the
> ideal place to do that is v4l2_ctrl_ops.s_ctrl, if that's
> at all possible.
Yeah, this particular check can be moved to s_ctrl handler.
>
> Driver's mem2mem device_run are executed in the context
> of a work_struct and the failure won't really get reported
> up the stack.
Well, at least there will be a notice in dmesg. Not ideal, I know.
>
> > padding = (u8 *)vb2_plane_vaddr(&run->src->vb2_buf, 0) +
> >
> > slice_params->data_byte_offset - 1;
> >
> > + /* at least one bit must be set in that byte */
> > + if (*padding == 0)
> > + return -EINVAL;
> > +
>
> Maybe this is something to check at cedrus_buf_prepare(),
> when the buffer is queued?
I don't think so. This check is HEVC specific, but cedrus_buf_prepare() is not
and we need to have slice control ready, which I'm not sure is the case for
cedrus_buf_prepare().
Best regards,
Jernej
>
> Thanks,
> Ezequiel
>
> > for (count = 0; count < 8; count++)
> >
> > if (*padding & (1 << count))
> >
> > break;
> >
> > --
> > 2.36.1
Hi Jernej,
On Tue, Jul 12, 2022 at 11:25:00PM +0200, Jernej Škrabec wrote:
> Hi Ezequiel.
>
> Dne ponedeljek, 11. julij 2022 ob 23:31:11 CEST je Ezequiel Garcia napisal(a):
> > On Mon, Jun 20, 2022 at 07:55:15PM +0200, Jernej Skrabec wrote:
> > > Now that we have infrastructure for reporting errors, let's add two
> > > checks, which will make sure slice can be actually decoded.
> > >
> > > Signed-off-by: Jernej Skrabec <[email protected]>
> > > ---
> > >
> > > drivers/staging/media/sunxi/cedrus/cedrus_h265.c | 8 ++++++++
> > > 1 file changed, 8 insertions(+)
> > >
> > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> > > b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c index
> > > cfde4ccf6011..99020b9f9ff8 100644
> > > --- a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> > > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> >
> > Now that you've allowed setup to fail, I would suggest
> > to have some documentation/comments on struct cedrus_dec_ops,
> > to set the expectation/rules for each ops, including the
> > call paths for each operation, which of them are allowed to sleep,
> > etc.
>
> Documentation can be always added, but it should be separate patch.
>
Of course, this wasn't a comment meant to block the patch in any way.
> >
> > > @@ -435,9 +435,17 @@ static int cedrus_h265_setup(struct cedrus_ctx *ctx,
> > > struct cedrus_run *run)>
> > > * instead of start of slice data. Padding is 8 bits at most (one
> bit
> > > set to 1 and * at most seven bits set to 0), so we have to
> inspect
> > > only one byte before slice data. */
> > >
> > > +
> > > + if (slice_params->data_byte_offset == 0)
> > > + return -EOPNOTSUPP;
> > > +
> >
> > AFAICS, cedrus_h265_setup is called from .device_run.
> > We've been discussing control validation before, and I think the
> > ideal place to do that is v4l2_ctrl_ops.s_ctrl, if that's
> > at all possible.
>
> Yeah, this particular check can be moved to s_ctrl handler.
>
> >
> > Driver's mem2mem device_run are executed in the context
> > of a work_struct and the failure won't really get reported
> > up the stack.
>
> Well, at least there will be a notice in dmesg. Not ideal, I know.
>
> >
> > > padding = (u8 *)vb2_plane_vaddr(&run->src->vb2_buf, 0) +
> > >
> > > slice_params->data_byte_offset - 1;
> > >
> > > + /* at least one bit must be set in that byte */
> > > + if (*padding == 0)
> > > + return -EINVAL;
> > > +
> >
> > Maybe this is something to check at cedrus_buf_prepare(),
> > when the buffer is queued?
>
> I don't think so. This check is HEVC specific, but cedrus_buf_prepare() is not
> and we need to have slice control ready, which I'm not sure is the case for
> cedrus_buf_prepare().
>
Hm... this is indeed a special case. The buffer contents
depend on a control, and both buffer and control are part of the same
request.
At least the decoding job would fail, and would get signaled
by the dequeued CAPTURE buffers and the V4L2_BUF_FLAG_ERROR flag,
which makes perfect sense.
In general vb2_ops.buf_prepare() is called for each
buffer (either through VIDIOC_QBUF or through MEDIA_REQUEST_IOC_QUEUE),
so for some buffer validations .buf_prepare() _might_ work better
than .device_run for validation.
In any case, the patch looks good, I don't think these
comments should block the patch:
Reviewed-by: Ezequiel Garcia <[email protected]>
Thanks,
Ezequiel
> Best regards,
> Jernej
>
> >
> > Thanks,
> > Ezequiel
> >
> > > for (count = 0; count < 8; count++)
> > >
> > > if (*padding & (1 << count))
> > >
> > > break;
> > >
> > > --
> > > 2.36.1
>
>