perf top: Exit if specified --vmlinux can't be used

As we do lazy loading of symtabs we only will know if the
specified vmlinux file is invalid when we actually have a hit in
kernel space and then try to load it. So if we get kernel hits
and there are _no_ symbols in the DSO backing the kernel map,
bail out.

Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1264633557-17597-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 23 insertions, 1 deletions

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 2227b84aa002..78f9c4576a0c 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -951,9 +951,31 @@ static void event__process_sample(const event_t *self,
         }
 
         if (event__preprocess_sample(self, session, &al, symbol_filter) < 0 ||
-            al.sym == NULL || al.filtered)
+            al.filtered)
                 return;
 
+        if (al.sym == NULL) {
+                /*
+                 * As we do lazy loading of symtabs we only will know if the
+                 * specified vmlinux file is invalid when we actually have a
+                 * hit in kernel space and then try to load it. So if we get
+                 * here and there are _no_ symbols in the DSO backing the
+                 * kernel map, bail out.
+                 *
+                 * We may never get here, for instance, if we use -K/
+                 * --hide-kernel-symbols, even if the user specifies an
+                 * invalid --vmlinux ;-)
+                 */
+                if (al.map == session->vmlinux_maps[MAP__FUNCTION] &&
+                    RB_EMPTY_ROOT(&al.map->dso->symbols[MAP__FUNCTION])) {
+                        pr_err("The %s file can't be used\n",
+                               symbol_conf.vmlinux_name);
+                        exit(1);
+                }
+
+                return;
+        }
+
         syme = symbol__priv(al.sym);
         if (!syme->skip) {
                 syme->count[counter]++;