From: Namhyung Kim <namhyung@kernel.org>
Date: Fri, 25 Aug 2023 15:25:50 +0000 (-0700)
Subject: libperf: Add perf_record_header_attr_id()
X-Git-Tag: v6.6-rc1~4^2~18
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=baec60800dd4a379546f3ba311574d907a01a77d;p=thirdparty%2Fkernel%2Flinux.git

libperf: Add perf_record_header_attr_id()

The HEADER_ATTR record has an event attr followed by the id array.  But
perf data from a different version could have different size of attr.

So it cannot just use event->attr.id to access the array.  Let's add the
perf_record_header_attr_id() macro to calculate the start of the array.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230825152552.112913-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
index ba2dcf64f4e63..e563dd8c3628f 100644
--- a/tools/lib/perf/include/perf/event.h
+++ b/tools/lib/perf/include/perf/event.h
@@ -151,6 +151,10 @@ struct perf_record_header_attr {
 	__u64			 id[];
 };
 
+/* Returns the pointer to id array based on the actual attr size. */
+#define perf_record_header_attr_id(evt)			\
+	((void *)&(evt)->attr.attr + (evt)->attr.attr.size)
+
 enum {
 	PERF_CPU_MAP__CPUS = 0,
 	PERF_CPU_MAP__MASK = 1,