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From: Namhyung Kim <namhyung@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>, Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Ingo Molnar <mingo@kernel.org>, Paul Mackerras <paulus@samba.org>,
	Namhyung Kim <namhyung.kim@lge.com>,
	Namhyung Kim <namhyung@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	David Ahern <dsahern@gmail.com>, Andi Kleen <andi@firstfloor.org>
Subject: [PATCH 2/3] perf ui/tui: Fix off-by-one in hist_browser__update_nr_entries()
Date: Thu, 17 Apr 2014 16:53:25 +0900	[thread overview]
Message-ID: <1397721206-15393-3-git-send-email-namhyung@kernel.org> (raw)
In-Reply-To: <1397721206-15393-1-git-send-email-namhyung@kernel.org>

The nr_entries variable is increased inside the loop in the function
but it also counts when hists__filter_entries() returns NULL.  Thus
the end result will have actual count + 1.

It'd become a problem especially there's no entry at all - it'd get a
segfault during referencing a NULL pointer.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/ui/browsers/hists.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 4d416984c59d..e86b95cc55db 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -1349,9 +1349,10 @@ static void hist_browser__update_pcnt_entries(struct hist_browser *hb)
 	struct rb_node *nd = rb_first(&hb->hists->entries);
 
 	while (nd) {
-		nr_entries++;
 		nd = hists__filter_entries(rb_next(nd), hb->hists,
 					   hb->min_pcnt);
+		if (nd)
+			nr_entries++;
 	}
 
 	hb->nr_pcnt_entries = nr_entries;
-- 
1.9.2


  parent reply	other threads:[~2014-04-17  7:53 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-17  7:53 [PATCH 0/3] perf top/tui: Fixes for percentage filter behavior Namhyung Kim
2014-04-17  7:53 ` [PATCH 1/3] perf hists: Add missing updates on nr_non_filtered_entries Namhyung Kim
2014-04-17 13:10   ` Jiri Olsa
2014-04-17 13:50     ` Namhyung Kim
2014-04-17  7:53 ` Namhyung Kim [this message]
2014-04-17  7:53 ` [PATCH 3/3] perf top/tui: Update nr_entries properly after filter is applied Namhyung Kim
2014-04-17 13:10   ` Jiri Olsa
2014-04-17 13:12   ` Jiri Olsa
2014-04-17 13:52     ` Namhyung Kim
2014-04-17 12:00 ` [PATCH 0/3] perf top/tui: Fixes for percentage filter behavior Jiri Olsa
2014-04-17 13:38   ` Namhyung Kim
2014-04-17 18:52     ` Jiri Olsa
2014-04-18  6:55       ` Namhyung Kim

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