perf evlist: Introduce perf_evlist__strerror_tp method

Out of 'perf trace', should be used by other tools that uses
tracepoints.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ramkumar Ramachandra <artagnon@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-lyvtxhchz4ga8fwht15x8wou@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index cb9523f50a3..6737420891c 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1126,3 +1126,30 @@ size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp)
 
 	return printed + fprintf(fp, "\n");;
 }
+
+int perf_evlist__strerror_tp(struct perf_evlist *evlist __maybe_unused,
+			     int err, char *buf, size_t size)
+{
+	char sbuf[128];
+
+	switch (err) {
+	case ENOENT:
+		scnprintf(buf, size, "%s",
+			  "Error:\tUnable to find debugfs\n"
+			  "Hint:\tWas your kernel was compiled with debugfs support?\n"
+			  "Hint:\tIs the debugfs filesystem mounted?\n"
+			  "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
+		break;
+	case EACCES:
+		scnprintf(buf, size,
+			  "Error:\tNo permissions to read %s/tracing/events/raw_syscalls\n"
+			  "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
+			  debugfs_mountpoint, debugfs_mountpoint);
+		break;
+	default:
+		scnprintf(buf, size, "%s", strerror_r(err, sbuf, sizeof(sbuf)));
+		break;
+	}
+
+	return 0;
+}