Commit 1746212d authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf inject: Use perf_data__read() for auxtrace 



In copy_bytes(), it reads the data from the (input) fd and writes it to
the output file.  But it does with the read(2) unconditionally which
caused a problem of mixing buffered vs unbuffered I/O together.

You can see the problem when using pipes.

  $ perf record -e intel_pt// -o- true | perf inject -b > /dev/null
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  0x45c0 [0x30]: failed to process type: 71

It should use perf_data__read() to honor the 'use_stdio' setting.

Fixes: 60136667 ("perf data: Allow to use stdio functions for pipe mode")
Reviewed-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarJames Clark <james.clark@arm.com>
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20230131023350.1903992-2-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent c6535b6b

tools/perf/builtin-inject.c

+3 −3
Original line number Diff line number Diff line
@@ -215,14 +215,14 @@ static int perf_event__repipe_event_update(struct perf_tool *tool, 


#ifdef HAVE_AUXTRACE_SUPPORT



static int copy_bytes(struct perf_inject *inject, int fd, off_t size)

static int copy_bytes(struct perf_inject *inject, struct perf_data *data, off_t size)

{

	char buf[4096];

	ssize_t ssz;

	int ret;



	while (size > 0) {

		ssz = read(fd, buf, min(size, (off_t)sizeof(buf)));

		ssz = perf_data__read(data, buf, min(size, (off_t)sizeof(buf)));

		if (ssz < 0)

			return -errno;

		ret = output_bytes(inject, buf, ssz);
@@ -260,7 +260,7 @@ static s64 perf_event__repipe_auxtrace(struct perf_session *session, 
		ret = output_bytes(inject, event, event->header.size);

		if (ret < 0)

			return ret;

		ret = copy_bytes(inject, perf_data__fd(session->data),

		ret = copy_bytes(inject, session->data,

				 event->auxtrace.size);

	} else {

		ret = output_bytes(inject, event,