[PATCH net-next 1/3] perf: pad raw data samples automatically

From: Alexei Starovoitov
Date: Tue Oct 20 2015 - 23:03:39 EST


Instead of WARN_ON in perf_event_output() on unpaded raw samples,
pad them automatically.

Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
---
kernel/events/core.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index b11756f9b6dc..64754bfecd70 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5286,9 +5286,15 @@ void perf_output_sample(struct perf_output_handle *handle,

if (sample_type & PERF_SAMPLE_RAW) {
if (data->raw) {
- perf_output_put(handle, data->raw->size);
- __output_copy(handle, data->raw->data,
- data->raw->size);
+ u32 raw_size = data->raw->size;
+ u32 real_size = round_up(raw_size + sizeof(u32),
+ sizeof(u64)) - sizeof(u32);
+ u64 zero = 0;
+
+ perf_output_put(handle, real_size);
+ __output_copy(handle, data->raw->data, raw_size);
+ if (real_size - raw_size)
+ __output_copy(handle, &zero, real_size - raw_size);
} else {
struct {
u32 size;
@@ -5420,8 +5426,7 @@ void perf_prepare_sample(struct perf_event_header *header,
else
size += sizeof(u32);

- WARN_ON_ONCE(size & (sizeof(u64)-1));
- header->size += size;
+ header->size += round_up(size, sizeof(u64));
}

if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
--
1.7.9.5

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