[tip:perf/core] perf tools: Enhance parsing events tracepoint error output

[tip-bot for Jiri Olsa]

Commit-ID:  196581717d85f59365dc9303685cd5b1cdf106a3
Gitweb: http://git.kernel.org/tip/196581717d85f59365dc9303685cd5b1cdf106a3
Author: Jiri Olsa 
AuthorDate: Mon, 7 Sep 2015 10:38:07 +0200
Committer:  Arnaldo Carvalho de Melo 
CommitDate: Tue, 15 Sep 2015 09:48:33 -0300

perf tools: Enhance parsing events tracepoint error output

Enhancing parsing events tracepoint error output. Adding
more verbose output when the tracepoint is not found or
the tracing event path cannot be access.

  $ sudo perf record -e sched:sched_krava ls
  event syntax error: 'sched:sched_krava'
   \___ unknown tracepoint

  Error:  File /sys/kernel/debug/tracing//tracing/events/sched/sched_krava not 
found.
  Hint:   Perhaps this kernel misses some CONFIG_ setting to enable this 
feature?.

  Run 'perf list' for a list of valid events
  ...

  $ perf record -e sched:sched_krava ls
  event syntax error: 'sched:sched_krava'
   \___ can't access trace events

  Error:  No permissions to read 
/sys/kernel/debug/tracing//tracing/events/sched/sched_krava
  Hint:   Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'

  Run 'perf list' for a list of valid events
  ...

Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Raphael Beamonte 
Cc: David Ahern 
Cc: Matt Fleming 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: 
http://lkml.kernel.org/r/1441615087-13886-6-git-send-email-jo...@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
---
 tools/perf/util/parse-events.c | 35 ---
 tools/perf/util/parse-events.y | 16 +---
 2 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index c47831c..d3fb90b 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -387,6 +387,33 @@ int parse_events_add_cache(struct list_head *list, int 
*idx,
return add_event(list, idx, , name, NULL);
 }
 
+static void tracepoint_error(struct parse_events_error *error, int err,
+char *sys, char *name)
+{
+   char help[BUFSIZ];
+
+   /*
+* We get error directly from syscall errno ( > 0),
+* or from encoded pointer's error ( < 0).
+*/
+   err = abs(err);
+
+   switch (err) {
+   case EACCES:
+   error->str = strdup("can't access trace events");
+   break;
+   case ENOENT:
+   error->str = strdup("unknown tracepoint");
+   break;
+   default:
+   error->str = strdup("failed to add tracepoint");
+   break;
+   }
+
+   tracing_path__strerror_open_tp(err, help, sizeof(help), sys, name);
+   error->help = strdup(help);
+}
+
 static int add_tracepoint(struct list_head *list, int *idx,
  char *sys_name, char *evt_name,
  struct parse_events_error *error __maybe_unused)
@@ -394,8 +421,10 @@ static int add_tracepoint(struct list_head *list, int *idx,
struct perf_evsel *evsel;
 
evsel = perf_evsel__newtp_idx(sys_name, evt_name, (*idx)++);
-   if (IS_ERR(evsel))
+   if (IS_ERR(evsel)) {
+   tracepoint_error(error, PTR_ERR(evsel), sys_name, evt_name);
return PTR_ERR(evsel);
+   }
 
list_add_tail(>node, list);
return 0;
@@ -413,7 +442,7 @@ static int add_tracepoint_multi_event(struct list_head 
*list, int *idx,
snprintf(evt_path, MAXPATHLEN, "%s/%s", tracing_events_path, sys_name);
evt_dir = opendir(evt_path);
if (!evt_dir) {
-   perror("Can't open event dir");
+   tracepoint_error(error, errno, sys_name, evt_name);
return -1;
}
 
@@ -453,7 +482,7 @@ static int add_tracepoint_multi_sys(struct list_head *list, 
int *idx,
 
events_dir = opendir(tracing_events_path);
if (!events_dir) {
-   perror("Can't open event dir");
+   tracepoint_error(error, errno, sys_name, evt_name);
return -1;
}
 
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index 54a3004..8bcc458 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -371,28 +371,30 @@ event_legacy_tracepoint:
 PE_NAME '-' PE_NAME ':' PE_NAME
 {
struct parse_events_evlist *data = _data;
+   struct parse_events_error *error = data->error;
struct list_head *list;
char sys_name[128];
snprintf(_name, 128, "%s-%s", $1, $3);
 
ALLOC_LIST(list);
-   ABORT_ON(parse_events_add_tracepoint(list, >idx, _name, $5, 
data->error));
+   if (parse_events_add_tracepoint(list, >idx, _name, $5, 
error)) {
+   if (error)
+   error->idx = @1.first_column;
+   return -1;
+   }
$$ = list;
 }
 |
 PE_NAME ':' PE_NAME
 {
struct parse_events_evlist *data = _data;
+   

[tip:perf/core] perf tools: Enhance parsing events tracepoint error output

[tip-bot for Jiri Olsa]

Commit-ID:  196581717d85f59365dc9303685cd5b1cdf106a3
Gitweb: http://git.kernel.org/tip/196581717d85f59365dc9303685cd5b1cdf106a3
Author: Jiri Olsa 
AuthorDate: Mon, 7 Sep 2015 10:38:07 +0200
Committer:  Arnaldo Carvalho de Melo 
CommitDate: Tue, 15 Sep 2015 09:48:33 -0300

perf tools: Enhance parsing events tracepoint error output

Enhancing parsing events tracepoint error output. Adding
more verbose output when the tracepoint is not found or
the tracing event path cannot be access.

  $ sudo perf record -e sched:sched_krava ls
  event syntax error: 'sched:sched_krava'
   \___ unknown tracepoint

  Error:  File /sys/kernel/debug/tracing//tracing/events/sched/sched_krava not 
found.
  Hint:   Perhaps this kernel misses some CONFIG_ setting to enable this 
feature?.

  Run 'perf list' for a list of valid events
  ...

  $ perf record -e sched:sched_krava ls
  event syntax error: 'sched:sched_krava'
   \___ can't access trace events

  Error:  No permissions to read 
/sys/kernel/debug/tracing//tracing/events/sched/sched_krava
  Hint:   Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'

  Run 'perf list' for a list of valid events
  ...

Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Raphael Beamonte 
Cc: David Ahern 
Cc: Matt Fleming 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: 
http://lkml.kernel.org/r/1441615087-13886-6-git-send-email-jo...@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
---
 tools/perf/util/parse-events.c | 35 ---
 tools/perf/util/parse-events.y | 16 +---
 2 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index c47831c..d3fb90b 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -387,6 +387,33 @@ int parse_events_add_cache(struct list_head *list, int 
*idx,
return add_event(list, idx, , name, NULL);
 }
 
+static void tracepoint_error(struct parse_events_error *error, int err,
+char *sys, char *name)
+{
+   char help[BUFSIZ];
+
+   /*
+* We get error directly from syscall errno ( > 0),
+* or from encoded pointer's error ( < 0).
+*/
+   err = abs(err);
+
+   switch (err) {
+   case EACCES:
+   error->str = strdup("can't access trace events");
+   break;
+   case ENOENT:
+   error->str = strdup("unknown tracepoint");
+   break;
+   default:
+   error->str = strdup("failed to add tracepoint");
+   break;
+   }
+
+   tracing_path__strerror_open_tp(err, help, sizeof(help), sys, name);
+   error->help = strdup(help);
+}
+
 static int add_tracepoint(struct list_head *list, int *idx,
  char *sys_name, char *evt_name,
  struct parse_events_error *error __maybe_unused)
@@ -394,8 +421,10 @@ static int add_tracepoint(struct list_head *list, int *idx,
struct perf_evsel *evsel;
 
evsel = perf_evsel__newtp_idx(sys_name, evt_name, (*idx)++);
-   if (IS_ERR(evsel))
+   if (IS_ERR(evsel)) {
+   tracepoint_error(error, PTR_ERR(evsel), sys_name, evt_name);
return PTR_ERR(evsel);
+   }
 
list_add_tail(>node, list);
return 0;
@@ -413,7 +442,7 @@ static int add_tracepoint_multi_event(struct list_head 
*list, int *idx,
snprintf(evt_path, MAXPATHLEN, "%s/%s", tracing_events_path, sys_name);
evt_dir = opendir(evt_path);
if (!evt_dir) {
-   perror("Can't open event dir");
+   tracepoint_error(error, errno, sys_name, evt_name);
return -1;
}
 
@@ -453,7 +482,7 @@ static int add_tracepoint_multi_sys(struct list_head *list, 
int *idx,
 
events_dir = opendir(tracing_events_path);
if (!events_dir) {
-   perror("Can't open event dir");
+   tracepoint_error(error, errno, sys_name, evt_name);
return -1;
}
 
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index 54a3004..8bcc458 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -371,28 +371,30 @@ event_legacy_tracepoint:
 PE_NAME '-' PE_NAME ':' PE_NAME
 {
struct parse_events_evlist *data = _data;
+   struct parse_events_error *error = data->error;
struct list_head *list;
char sys_name[128];
snprintf(_name, 128, "%s-%s", $1, $3);
 
ALLOC_LIST(list);
-   ABORT_ON(parse_events_add_tracepoint(list, >idx, _name, $5, 
data->error));
+   if (parse_events_add_tracepoint(list, >idx, _name, $5, 
error)) {
+   if