On Thu, 15 Jun 2023 18:50:35 -0700, Umesh Nerlige Ramappa wrote:
>
> For reports that are not powers of 2, reports at the end of the OA
> buffer may get split across the buffer boundary. When zeroing out such
> reports, take the split into consideration.
>
> Fixes: 09a36015d9a0 ("drm/i915/perf: Clear out entire reports after reading if not power of 2 size")
> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/i915_perf.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index b5491a382bfd..9a8e329c5b5e 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -867,8 +867,17 @@ static int gen8_append_oa_reports(struct i915_perf_stream *stream,
> oa_report_id_clear(stream, report32);
> oa_timestamp_clear(stream, report32);
> } else {
> + u8 *oa_buf_end = stream->oa_buffer.vaddr +
> + stream->oa_buffer.vma->size;
Probably: "u8 *oa_buf_end = oa_buf_base + OA_BUFFER_SIZE;" ?
We haven't used 'stream->oa_buffer.vma->size' much in this file so I think
better to stick to OA_BUFFER_SIZE.
> + u32 part = (u32)((void *)oa_buf_end - (void *)report32);
This should be sufficient, no need to cast as above I think:
u32 part = oa_buf_end - report32;
or
u32 part = oa_buf_end - report;
> +
> /* Zero out the entire report */
> - memset(report32, 0, report_size);
> + if (report_size <= part) {
> + memset(report32, 0, report_size);
> + } else {
> + memset(report32, 0, part);
> + memset(oa_buf_base, 0, report_size - part);
> + }
Thanks for finding this:
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
> }
> }
>
> --
> 2.36.1
>
