Re: [PATCH] perf powerpc-vpadtl: Fix raw_size of DTL samples
From: Athira Rajeev
Date: Fri Aug 28 2026 - 08:07:49 EST
> On 25 Aug 2026, at 3:17 PM, Wang Yan <wangyan01@xxxxxxxxxx> wrote:
>
> In powerpc_vpadtl_sample(), raw_data of the synthetic sample points to a
> struct powerpc_vpadtl_entry (48 bytes), but raw_size is set to
> sizeof(record). record is a struct powerpc_vpadtl_entry pointer, so
> sizeof(record) is the size of the pointer (8 bytes on 64-bit) rather
> than the size of the record itself.
>
> As a result, consumers that bound their access to raw_data by raw_size
> only see or copy the first 8 bytes of each DTL entry instead of the full
> record.
>
> Use sizeof(*record) so that raw_size reflects the actual length of the
> raw data.
>
> Fixes: 8644834a482a ("perf powerpc: Process the DTL entries in queue and deliver samples")
> Signed-off-by: Wang Yan <wangyan01@xxxxxxxxxx>
Reviewed-by: Athira Rajeev <atrajeev@xxxxxxxxxxxxx>
Thanks
Athira
> ---
> tools/perf/util/powerpc-vpadtl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/powerpc-vpadtl.c b/tools/perf/util/powerpc-vpadtl.c
> index 710f3093f3f9..af6783cfdb53 100644
> --- a/tools/perf/util/powerpc-vpadtl.c
> +++ b/tools/perf/util/powerpc-vpadtl.c
> @@ -196,7 +196,7 @@ static int powerpc_vpadtl_sample(struct powerpc_vpadtl_entry *record,
> sample.cpumode = PERF_RECORD_MISC_KERNEL;
> sample.time = save;
> sample.raw_data = record;
> - sample.raw_size = sizeof(record);
> + sample.raw_size = sizeof(*record);
> event.sample.header.type = PERF_RECORD_SAMPLE;
> event.sample.header.misc = sample.cpumode;
> event.sample.header.size = sizeof(struct perf_event_header);
> --
> 2.25.1
>