perf probe: Show accessible local variables

[deliverable/linux.git] / tools / perf / util / probe-event.c

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index fcc16e4349df9f3353ac03f975d9c1be9938863a..288ebe8279d2bb8b4ac124b7b76b2f1cd033b68d 100644 (file)
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -378,6 +378,72 @@ end:
        return ret;
 }
 
+static int show_available_vars_at(int fd, struct perf_probe_event *pev,
+                                 int max_vls)
+{
+       char *buf;
+       int ret, i;
+       struct str_node *node;
+       struct variable_list *vls = NULL, *vl;
+
+       buf = synthesize_perf_probe_point(&pev->point);
+       if (!buf)
+               return -EINVAL;
+       pr_debug("Searching variables at %s\n", buf);
+
+       ret = find_available_vars_at(fd, pev, &vls, max_vls);
+       if (ret > 0) {
+               /* Some variables were found */
+               fprintf(stdout, "Available variables at %s\n", buf);
+               for (i = 0; i < ret; i++) {
+                       vl = &vls[i];
+                       /*
+                        * A probe point might be converted to
+                        * several trace points.
+                        */
+                       fprintf(stdout, "\t@<%s+%lu>\n", vl->point.symbol,
+                               vl->point.offset);
+                       free(vl->point.symbol);
+                       if (vl->vars) {
+                               strlist__for_each(node, vl->vars)
+                                       fprintf(stdout, "\t\t%s\n", node->s);
+                               strlist__delete(vl->vars);
+                       } else
+                               fprintf(stdout, "(No variables)\n");
+               }
+               free(vls);
+       } else
+               pr_err("Failed to find variables at %s (%d)\n", buf, ret);
+
+       free(buf);
+       return ret;
+}
+
+/* Show available variables on given probe point */
+int show_available_vars(struct perf_probe_event *pevs, int npevs,
+                       int max_vls)
+{
+       int i, fd, ret = 0;
+
+       ret = init_vmlinux();
+       if (ret < 0)
+               return ret;
+
+       fd = open_vmlinux();
+       if (fd < 0) {
+               pr_warning("Failed to open debuginfo file.\n");
+               return fd;
+       }
+
+       setup_pager();
+
+       for (i = 0; i < npevs && ret >= 0; i++)
+               ret = show_available_vars_at(fd, &pevs[i], max_vls);
+
+       close(fd);
+       return ret;
+}
+
 #else  /* !DWARF_SUPPORT */
 
 static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,
@@ -409,6 +475,12 @@ int show_line_range(struct line_range *lr __unused)
        return -ENOSYS;
 }
 
+int show_available_vars(struct perf_probe_event *pevs __unused,
+                       int npevs __unused, int max_probe_points __unused)
+{
+       pr_warning("Debuginfo-analysis is not supported.\n");
+       return -ENOSYS;
+}
 #endif
 
 int parse_line_range_desc(const char *arg, struct line_range *lr)