perf hists browser: Handle browsing empty hists tree

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 15 insertions, 7 deletions

diff --git a/tools/perf/util/ui/browsers/hists.c b/tools/perf/util/ui/browsers/hists.c
index c27ab35042f1..c98e6f81d285 100644
--- a/tools/perf/util/ui/browsers/hists.c
+++ b/tools/perf/util/ui/browsers/hists.c
@@ -639,6 +639,9 @@ static void ui_browser__hists_seek(struct ui_browser *self,
         struct rb_node *nd;
         bool first = true;
 
+        if (self->nr_entries == 0)
+                return;
+
         switch (whence) {
         case SEEK_SET:
                 nd = hists__filter_entries(rb_first(self->entries));
@@ -820,8 +823,8 @@ int hists__browse(struct hists *self, const char *helpline,
         hists__browser_title(self, msg, sizeof(msg), ev_name,
                              dso_filter, thread_filter);
         while (1) {
-                const struct thread *thread;
-                const struct dso *dso;
+                const struct thread *thread = NULL;
+                const struct dso *dso = NULL;
                 char *options[16];
                 int nr_options = 0, choice = 0, i,
                     annotate = -2, zoom_dso = -2, zoom_thread = -2,
@@ -829,8 +832,10 @@ int hists__browse(struct hists *self, const char *helpline,
 
                 key = hist_browser__run(browser, msg);
 
-                thread = hist_browser__selected_thread(browser);
-                dso = browser->selection->map ? browser->selection->map->dso : NULL;
+                if (browser->he_selection != NULL) {
+                        thread = hist_browser__selected_thread(browser);
+                        dso = browser->selection->map ? browser->selection->map->dso : NULL;
+                }
 
                 switch (key) {
                 case NEWT_KEY_TAB:
@@ -841,7 +846,8 @@ int hists__browse(struct hists *self, const char *helpline,
                          */
                         goto out_free_stack;
                 case 'a':
-                        if (browser->selection->map == NULL &&
+                        if (browser->selection == NULL ||
+                            browser->selection->map == NULL ||
                             browser->selection->map->dso->annotate_warned)
                                 continue;
                         goto do_annotate;
@@ -887,7 +893,8 @@ int hists__browse(struct hists *self, const char *helpline,
                         goto out_free_stack;
                 }
 
-                if (browser->selection->sym != NULL &&
+                if (browser->selection != NULL &&
+                    browser->selection->sym != NULL &&
                     !browser->selection->map->dso->annotate_warned &&
                     asprintf(&options[nr_options], "Annotate %s",
                              browser->selection->sym->name) > 0)
@@ -906,7 +913,8 @@ int hists__browse(struct hists *self, const char *helpline,
                              (dso->kernel ? "the Kernel" : dso->short_name)) > 0)
                         zoom_dso = nr_options++;
 
-                if (browser->selection->map != NULL &&
+                if (browser->selection != NULL &&
+                    browser->selection->map != NULL &&
                     asprintf(&options[nr_options], "Browse map details") > 0)
                         browse_map = nr_options++;