perf ui browser: Fix segfault caused by off by one handling END key

$ perf record ls
$ perf report

Press 'down enter end'

Result:

Program received signal SIGSEGV, Segmentation fault.

The UI browser, used on a argv array would access past the end of the
array on SEEK_END because it wasn't using 'nr_entries - 1', fix it.

Reported-by: v.karpov@samsung.com
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: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=59291
Link: http://lkml.kernel.org/n/tip-3g83ipasqi219ktv764xzzjs@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/ui/browser.c b/tools/perf/ui/browser.c
index 3648d4e..cbaa7af 100644 (file)
--- a/tools/perf/ui/browser.c
+++ b/tools/perf/ui/browser.c
@@ -569,7 +569,7 @@ void ui_browser__argv_seek(struct ui_browser *browser, off_t offset, int whence)
                browser->top = browser->top + browser->top_idx + offset;
                break;
        case SEEK_END:
-               browser->top = browser->top + browser->nr_entries + offset;
+               browser->top = browser->top + browser->nr_entries - 1 + offset;
                break;
        default:
                return;