From: Namhyung Kim <namhyung@kernel.org>
To: He Kuang <hekuang@huawei.com>
Cc: acme@kernel.org, a.p.zijlstra@chello.nl, mingo@redhat.com,
paulus@samba.org, jolsa@kernel.org, wangnan0@huawei.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf hists browser: Fix segfault when all entries be filtered
Date: Tue, 10 Mar 2015 15:01:12 +0900 [thread overview]
Message-ID: <20150310060112.GB943@sejong> (raw)
In-Reply-To: <54FE6753.8090703@huawei.com>
Hi,
On Tue, Mar 10, 2015 at 11:38:59AM +0800, He Kuang wrote:
> ping..
> On 2015/3/4 12:13, He Kuang wrote:
> >When all perf report entries be filtered, the result of
> >hists__filter_entries() can be NULL, check the result before processing.
In that case, browser->nr_entries should be zero IMHO. But it seems
there's a place missing to update the number.
Thanks,
Namhyung
> >
> >Miss this checking will cause segmentation fault like this:
> >
> > $ perf report
> >
> >(filter all entries and left nothing, then zoom in/out)
> > perf: Segmentation fault
> > -------- backtrace --------
> > ../bin/perf[0x4d1858]
> > ../lib64/libc.so.6(+0x3545f)[0x7fe72fc1145f]
> > ../bin/perf[0x4cd9f5]
> > ../bin/perf[0x4ce176]
> > ../bin/perf[0x4d0506]
> > ../bin/perf[0x41a94f]
> > ../bin/perf[0x408cf2]
> > ../bin/perf[0x408455]
> > ../lib64/libc.so.6(__libc_start_main+0xf4)[0x7fe72fbfdbd4]
> > ../bin/perf[0x408584]
> >
> >Signed-off-by: He Kuang <hekuang@huawei.com>
> >---
> > tools/perf/ui/browsers/hists.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> >diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
> >index 788506e..1106bb8 100644
> >--- a/tools/perf/ui/browsers/hists.c
> >+++ b/tools/perf/ui/browsers/hists.c
> >@@ -992,6 +992,9 @@ static void ui_browser__hists_seek(struct ui_browser *browser,
> > * and stop when we printed enough lines to fill the screen.
> > */
> > do_offset:
> >+ if (!nd)
> >+ return;
> >+
> > if (offset > 0) {
> > do {
> > h = rb_entry(nd, struct hist_entry, rb_node);
>
>
> --
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prev parent reply other threads:[~2015-03-10 6:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-04 4:13 [PATCH] perf hists browser: Fix segfault when all entries be filtered He Kuang
2015-03-10 3:38 ` He Kuang
2015-03-10 6:01 ` Namhyung Kim [this message]
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