[PATCH 02/18] perf util: Add more debug message on failure path

[Namhyung Kim]

From: Namhyung Kim <namhyung....@lge.com>

It's helpful for debugging on tracing features.

Signed-off-by: Namhyung Kim <namhy...@kernel.org>
---
 tools/perf/util/header.c           |  4 ++-
 tools/perf/util/trace-event-read.c | 53 ++++++++++++++++++++++++++------------
 2 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index c3e5a3b817ab..f8afefbe99ae 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2721,8 +2721,10 @@ static int perf_evsel__prepare_tracepoint_event(struct 
perf_evsel *evsel,
        }
 
        event = pevent_find_event(pevent, evsel->attr.config);
-       if (event == NULL)
+       if (event == NULL) {
+               pr_debug("cannot find event format for %d\n", 
(int)evsel->attr.config);
                return -1;
+       }
 
        if (!evsel->name) {
                snprintf(bf, sizeof(bf), "%s:%s", event->system, event->name);
diff --git a/tools/perf/util/trace-event-read.c 
b/tools/perf/util/trace-event-read.c
index e084e5e654b6..0e3b3f527320 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -262,39 +262,53 @@ static int read_header_files(struct pevent *pevent)
 
 static int read_ftrace_file(struct pevent *pevent, unsigned long long size)
 {
+       int ret;
        char *buf;
 
        buf = malloc(size);
-       if (buf == NULL)
+       if (buf == NULL) {
+               pr_debug("memory allocation failure\n");
                return -1;
+       }
 
-       if (do_read(buf, size) < 0) {
-               free(buf);
-               return -1;
+       ret = do_read(buf, size);
+       if (ret < 0) {
+               pr_debug("error reading ftrace file.\n");
+               goto out;
        }
 
-       parse_ftrace_file(pevent, buf, size);
+       ret = parse_ftrace_file(pevent, buf, size);
+       if (ret < 0)
+               pr_debug("error parsing ftrace file.\n");
+out:
        free(buf);
-       return 0;
+       return ret;
 }
 
 static int read_event_file(struct pevent *pevent, char *sys,
                            unsigned long long size)
 {
+       int ret;
        char *buf;
 
        buf = malloc(size);
-       if (buf == NULL)
+       if (buf == NULL) {
+               pr_debug("memory allocation failure\n");
                return -1;
+       }
 
-       if (do_read(buf, size) < 0) {
+       ret = do_read(buf, size);
+       if (ret < 0) {
                free(buf);
-               return -1;
+               goto out;
        }
 
-       parse_event_file(pevent, buf, size, sys);
+       ret = parse_event_file(pevent, buf, size, sys);
+       if (ret < 0)
+               pr_debug("error parsing event file.\n");
+out:
        free(buf);
-       return 0;
+       return ret;
 }
 
 static int read_ftrace_files(struct pevent *pevent)
@@ -347,6 +361,7 @@ static int read_saved_cmdline(struct pevent *pevent)
 {
        unsigned long long size;
        char *buf;
+       int ret;
 
        /* it can have 0 size */
        size = read8(pevent);
@@ -354,18 +369,22 @@ static int read_saved_cmdline(struct pevent *pevent)
                return 0;
 
        buf = malloc(size + 1);
-       if (buf == NULL)
+       if (buf == NULL) {
+               pr_debug("memory allocation failure\n");
                return -1;
+       }
 
-       if (do_read(buf, size) < 0) {
-               free(buf);
-               return -1;
+       ret = do_read(buf, size);
+       if (ret < 0) {
+               pr_debug("error reading saved cmdlines\n");
+               goto out;
        }
 
        parse_saved_cmdline(pevent, buf, size);
-
+       ret = 0;
+out:
        free(buf);
-       return 0;
+       return ret;
 }
 
 ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe)
-- 
1.7.11.7

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