Commit-ID: dc240c5dc2a02e335c5bcb50ad3a1274818c8609
Gitweb: http://git.kernel.org/tip/dc240c5dc2a02e335c5bcb50ad3a1274818c8609
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Sat, 19 Sep 2015 16:47:07 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 28 Sep 2015 15:50:54 -0300
tools lib api fs: Store tracing mountpoint for better error message
Storing the actual tracing path mountpoint to display correct
error message hint ('Hint:' line). The error hint rediscovers
mountpoints, but it could be different from what we actually
used in tracing path.
Before we'd display debugfs mount even though tracefs was used:
$ 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/events/sched/sched_krava
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'
...
After this change, correct mountpoint is displayed:
$ 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/events/sched/sched_krava
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
...
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Raphael Beamonte <raphael.beamonte@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1442674027-19427-1-git-send-email-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/lib/api/fs/tracing_path.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c
index 38aca2d..0406a7d 100644
--- a/tools/lib/api/fs/tracing_path.c
+++ b/tools/lib/api/fs/tracing_path.c
@@ -12,12 +12,14 @@
#include "tracing_path.h"
+char tracing_mnt[PATH_MAX + 1] = "/sys/kernel/debug";
char tracing_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing";
char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";
static void __tracing_path_set(const char *tracing, const char *mountpoint)
{
+ snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint);
snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
mountpoint, tracing);
snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
@@ -109,19 +111,10 @@ static int strerror_open(int err, char *buf, size_t size, const char *filename)
"Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
break;
case EACCES: {
- const char *mountpoint = debugfs__mountpoint();
-
- if (!access(mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) {
- const char *tracefs_mntpoint = tracefs__mountpoint();
-
- if (tracefs_mntpoint)
- mountpoint = tracefs__mountpoint();
- }
-
snprintf(buf, size,
"Error:\tNo permissions to read %s/%s\n"
"Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
- tracing_events_path, filename, mountpoint);
+ tracing_events_path, filename, tracing_mnt);
}
break;
default:
--
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