[Mesa-dev] gallium: Reduce trace_dump_box_bytes size by box->x.

[Cherniak, Bruce]

> On Jun 26, 2017, at 2:10 PM, Marek Olšák <maraeo at gmail.com> wrote:
> 
> In my opinion, dumping resources isn't very useful. I think it would
> be better to remove that completely.

From Michel's response, sounds like dumping resources is useful, so... Back to my original
question, is this a valid fix?  It prevents a crash that happens on occasion while running
GALLIUM_TRACE.

I too would be interested in learning how to replay traces.  Would be very handy.

Thanks,
Bruce

> Marek
> 
> On Mon, Jun 26, 2017 at 6:28 PM, Cherniak, Bruce
> <bruce.cherniak at intel.com> wrote:
>> Back in February, I submitted a patch for review to address an a crash in GALLIUM_TRACE.
>> 
>> It never got a review, and I forgot to follow up on it.  Is this a correct fix and useful to anyone
>> else?
>> 
>> Thanks,
>> Bruce
>> 
>> ----
>> 
>> From patchwork Wed Feb  1 20:20:38 2017
>> Content-Type: text/plain; charset="utf-8"
>> MIME-Version: 1.0
>> Content-Transfer-Encoding: 7bit
>> Subject: [Mesa-dev] gallium: Reduce trace_dump_box_bytes size by box->x.
>> From: Bruce Cherniak <bruce.cherniak at intel.com>
>> X-Patchwork-Id: 136378
>> Message-Id: <1485980438-102650-1-git-send-email-bruce.cherniak at intel.com>
>> To: mesa-dev at lists.freedesktop.org
>> Date: Wed,  1 Feb 2017 14:20:38 -0600
>> 
>> If stride is supplied (as either stride or slice_stride),
>> trace_dump_box_bytes will try to read stride bytes, regardless whether
>> start address is offset by box->x.  This causes access outside mapped
>> region, and possible segv. (transfer_map stride and layer_stride are not
>> adjusted for box dimensions)
>> 
>> Note:  trace_dump_box_bytes only dumps PIPE_BUFFER resources, so there
>> shouldn't be any complicated boxes.  trace_dump_bytes doesn't handle them
>> anyway.
>> ---
>> src/gallium/drivers/trace/tr_dump.c | 8 +++++---
>> 1 file changed, 5 insertions(+), 3 deletions(-)
>> 
>> diff --git a/src/gallium/drivers/trace/tr_dump.c b/src/gallium/drivers/trace/tr_dump.c
>> index b173b8a..591e273 100644
>> --- a/src/gallium/drivers/trace/tr_dump.c
>> +++ b/src/gallium/drivers/trace/tr_dump.c
>> @@ -510,11 +510,13 @@ void trace_dump_box_bytes(const void *data,
>>       size = 0;
>>    } else {
>>       enum pipe_format format = resource->format;
>> -      if (slice_stride)
>> +      if (slice_stride) {
>> +         slice_stride -= util_format_get_blockwidth(format) * box->x;
>>          size = box->depth * slice_stride;
>> -      else if (stride)
>> +      } else if (stride) {
>> +         stride -= util_format_get_blockwidth(format) * box->x;
>>          size = util_format_get_nblocksy(format, box->height) * stride;
>> -      else {
>> +      } else {
>>          size = util_format_get_nblocksx(format, box->width) * util_format_get_blocksize(format);
>>       }
>>    }
>> 
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