Re: [PATCH 0/3] perf top/tui: Fixes for percentage filter behavior

[Jiri Olsa <jolsa@redhat.com>]

On Thu, Apr 17, 2014 at 04:53:23PM +0900, Namhyung Kim wrote:
> Hi,
> 
> This is a small fixes for a bug in perf top I found during some tests.
> It gets segfault if symbol filter found no entries - accessing NULL
> pointer in that case.

yep, I hit that yesterday as well, but I ended up just with
the patch below, your changes seems more comprehensive ;-)
going to review..

thanks,
jirka


> 
> The patches are also available at perf/percentage-v9 branch on my tree
> for your convenience.  I'm sorry for causing this bug..
> 
> Thanks,
> Namhyung
> 
> 
> Namhyung Kim (3):
>   perf hists: Add missing updates on nr_non_filtered_entries
>   perf ui/tui: Fix off-by-one in hist_browser__update_nr_entries()
>   perf top/tui: Update nr_entries properly after filter is applied
> 
>  tools/perf/ui/browsers/hists.c | 34 +++++++++++++++++++---------------
>  tools/perf/util/hist.c         |  8 +++++++-
>  tools/perf/util/hist.h         |  6 ++++++
>  3 files changed, 32 insertions(+), 16 deletions(-)
> 
> -- 
> 1.9.2
> 

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 4d41698..89c3ba0 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -866,6 +866,10 @@ static void ui_browser__hists_seek(struct ui_browser *browser,
 		return;
 	}
 
+	/* Nowhere to start from. */
+	if (!nd)
+		return;
+
 	/*
 	 * Moves not relative to the first visible entry invalidates its
 	 * row_offset: