1 files changed, 44 insertions, 33 deletions

diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 1a62daceb028..1542cd0d6799 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -877,35 +877,33 @@ int probe_cache__show_all_caches(struct strfilter *filter)
         return 0;
 }
 
+enum ftrace_readme {
+        FTRACE_README_PROBE_TYPE_X = 0,
+        FTRACE_README_KRETPROBE_OFFSET,
+        FTRACE_README_END,
+};
+
 static struct {
         const char *pattern;
-        bool    avail;
-        bool    checked;
-} probe_type_table[] = {
-#define DEFINE_TYPE(idx, pat, def_avail)        \
-        [idx] = {.pattern = pat, .avail = (def_avail)}
-        DEFINE_TYPE(PROBE_TYPE_U, "* u8/16/32/64,*", true),
-        DEFINE_TYPE(PROBE_TYPE_S, "* s8/16/32/64,*", true),
-        DEFINE_TYPE(PROBE_TYPE_X, "* x8/16/32/64,*", false),
-        DEFINE_TYPE(PROBE_TYPE_STRING, "* string,*", true),
-        DEFINE_TYPE(PROBE_TYPE_BITFIELD,
-                    "* b<bit-width>@<bit-offset>/<container-size>", true),
+        bool avail;
+} ftrace_readme_table[] = {
+#define DEFINE_TYPE(idx, pat)                   \
+        [idx] = {.pattern = pat, .avail = false}
+        DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
+        DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
 };
 
-bool probe_type_is_available(enum probe_type type)
+static bool scan_ftrace_readme(enum ftrace_readme type)
 {
+        int fd;
         FILE *fp;
         char *buf = NULL;
         size_t len = 0;
-        bool target_line = false;
-        bool ret = probe_type_table[type].avail;
-        int fd;
+        bool ret = false;
+        static bool scanned = false;
 
-        if (type >= PROBE_TYPE_END)
-                return false;
-        /* We don't have to check the type which supported by default */
-        if (ret || probe_type_table[type].checked)
-                return ret;
+        if (scanned)
+                goto result;
 
         fd = open_trace_file("README", false);
         if (fd < 0)
@@ -917,21 +915,34 @@ bool probe_type_is_available(enum probe_type type)
                 return ret;
         }
 
-        while (getline(&buf, &len, fp) > 0 && !ret) {
-                if (!target_line) {
-                        target_line = !!strstr(buf, " type: ");
-                        if (!target_line)
-                                continue;
-                } else if (strstr(buf, "\t          ") != buf)
-                        break;
-                ret = strglobmatch(buf, probe_type_table[type].pattern);
-        }
-        /* Cache the result */
-        probe_type_table[type].checked = true;
-        probe_type_table[type].avail = ret;
+        while (getline(&buf, &len, fp) > 0)
+                for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
+                        if (!ftrace_readme_table[i].avail)
+                                ftrace_readme_table[i].avail =
+                                        strglobmatch(buf, ftrace_readme_table[i].pattern);
+        scanned = true;
 
         fclose(fp);
         free(buf);
 
-        return ret;
+result:
+        if (type >= FTRACE_README_END)
+                return false;
+
+        return ftrace_readme_table[type].avail;
+}
+
+bool probe_type_is_available(enum probe_type type)
+{
+        if (type >= PROBE_TYPE_END)
+                return false;
+        else if (type == PROBE_TYPE_X)
+                return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
+
+        return true;
+}
+
+bool kretprobe_offset_is_supported(void)
+{
+        return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
 }