[PATCH 5/9] perf util: Handle failure case in trace_report()

From: Namhyung Kim
Date: Tue Mar 19 2013 - 04:57:51 EST


From: Namhyung Kim <namhyung.kim@xxxxxxx>

If pevent allocation in read_trace_init() fails, trace_report() will
return -1 and *ppevent is set to NULL. Its callers should check this
case and handle it properly.

This is also a preparation for the removal of *die() calls.

Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/header.c | 11 +++++++---
tools/perf/util/trace-event-read.c | 41 ++++++++++++++++++++++----------------
2 files changed, 32 insertions(+), 20 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index a9b7349f7c5f..f2c33c4cfc38 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1672,8 +1672,8 @@ static int process_tracing_data(struct perf_file_section *section __maybe_unused
struct perf_header *ph __maybe_unused,
int fd, void *data)
{
- trace_report(fd, data, false);
- return 0;
+ ssize_t ret = trace_report(fd, data, false);
+ return ret < 0 ? -1 : 0;
}

static int process_build_id(struct perf_file_section *section,
@@ -2752,6 +2752,11 @@ static int perf_evsel__prepare_tracepoint_event(struct perf_evsel *evsel,
if (evsel->tp_format)
return 0;

+ if (pevent == NULL) {
+ pr_debug("broken or missing trace data\n");
+ return -1;
+ }
+
event = pevent_find_event(pevent, evsel->attr.config);
if (event == NULL)
return -1;
@@ -3100,7 +3105,7 @@ int perf_event__process_tracing_data(union perf_event *event,
}
}

- if (size_read + padding != size) {
+ if (size_read + padding != size || session->pevent == NULL) {
pr_err("%s: tracing data size mismatch", __func__);
return -1;
}
diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index 7cb24635adf2..129362b97ca5 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -293,7 +293,10 @@ ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe)
int show_version = 0;
int show_funcs = 0;
int show_printk = 0;
- ssize_t size;
+ ssize_t size = -1;
+ struct pevent *pevent;
+
+ *ppevent = NULL;

calc_data_size = 1;
repipe = __repipe;
@@ -317,34 +320,38 @@ ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe)
file_bigendian = buf[0];
host_bigendian = bigendian();

- *ppevent = read_trace_init(file_bigendian, host_bigendian);
- if (*ppevent == NULL)
- die("read_trace_init failed");
+ pevent = read_trace_init(file_bigendian, host_bigendian);
+ if (pevent == NULL) {
+ pr_err("read_trace_init failed");
+ goto out;
+ }

read_or_die(buf, 1);
long_size = buf[0];

- page_size = read4(*ppevent);
-
- read_header_files(*ppevent);
+ page_size = read4(pevent);

- read_ftrace_files(*ppevent);
- read_event_files(*ppevent);
- read_proc_kallsyms(*ppevent);
- read_ftrace_printk(*ppevent);
+ read_header_files(pevent);
+ read_ftrace_files(pevent);
+ read_event_files(pevent);
+ read_proc_kallsyms(pevent);
+ read_ftrace_printk(pevent);

size = calc_data_size - 1;
calc_data_size = 0;
repipe = false;

if (show_funcs) {
- pevent_print_funcs(*ppevent);
- return size;
- }
- if (show_printk) {
- pevent_print_printk(*ppevent);
- return size;
+ pevent_print_funcs(pevent);
+ } else if (show_printk) {
+ pevent_print_printk(pevent);
}

+ *ppevent = pevent;
+ pevent = NULL;
+
+out:
+ if (pevent)
+ pevent_free(pevent);
return size;
}
--
1.7.11.7

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