Commit 2a76f6de authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
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perf synthetic events: Avoid write of uninitialized memory when generating... 


perf synthetic events: Avoid write of uninitialized memory when generating PERF_RECORD_MMAP* records

Account for alignment bytes in the zero-ing memset.

Fixes: 1a853e36 ("perf record: Allow specifying a pid to record")
Signed-off-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210309234945.419254-1-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 49f2675f

tools/perf/util/synthetic-events.c

+5 −4
Original line number Diff line number Diff line
@@ -424,7 +424,7 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, 


	while (!io.eof) {

		static const char anonstr[] = "//anon";

		size_t size;

		size_t size, aligned_size;



		/* ensure null termination since stack will be reused. */

		event->mmap2.filename[0] = '\0';
@@ -484,11 +484,12 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, 
		}



		size = strlen(event->mmap2.filename) + 1;

		size = PERF_ALIGN(size, sizeof(u64));

		aligned_size = PERF_ALIGN(size, sizeof(u64));

		event->mmap2.len -= event->mmap.start;

		event->mmap2.header.size = (sizeof(event->mmap2) -

					(sizeof(event->mmap2.filename) - size));

		memset(event->mmap2.filename + size, 0, machine->id_hdr_size);

					(sizeof(event->mmap2.filename) - aligned_size));

		memset(event->mmap2.filename + size, 0, machine->id_hdr_size +

			(aligned_size - size));

		event->mmap2.header.size += machine->id_hdr_size;

		event->mmap2.pid = tgid;

		event->mmap2.tid = pid;