Messages in this thread Patch in this message | | | Date | Thu, 3 Dec 2015 00:49:42 +0900 | From | Namhyung Kim <> | Subject | Re: [PATCH] perf hists browser: Fix segfault if use symbol filter in cmdline |
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Hi,
On Wed, Dec 02, 2015 at 11:28:52AM +0000, Wang Nan wrote: > If feed perf a symbol filter in cmdline and the result is empty, > pressing 'Enter' in the hist browser causes crash: > > # ./perf report perf.data <-- Common mistake for beginners > > Then press 'Enter': > > perf: Segmentation fault > -------- backtrace -------- > /home/wangnan/perf[0x53e578] > /lib64/libc.so.6(+0x3545f)[0x7f76bafe045f] > /home/wangnan/perf[0x539dd4] > /home/wangnan/perf(perf_evlist__tui_browse_hists+0x96)[0x53d216] > /home/wangnan/perf(cmd_report+0x1b9f)[0x442c7f] > /home/wangnan/perf[0x47efa2] > /home/wangnan/perf(main+0x5f5)[0x432fa5] > /lib64/libc.so.6(__libc_start_main+0xf4)[0x7f76bafccbd4] > /home/wangnan/perf[0x4330d4] > > This is because 'perf.data' is interperted as a symbol filter, and the > result is empty, so selection is empty. However, > hist_browser__toggle_fold() forgets to check it. > > This patch simply return faluse when selection is NULL.
s/faluse/false/
> > Signed-off-by: Wang Nan <wangnan0@huawei.com> > Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
One nitpick below..
> --- > tools/perf/ui/browsers/hists.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c > index dcdcbaf..33da341 100644 > --- a/tools/perf/ui/browsers/hists.c > +++ b/tools/perf/ui/browsers/hists.c > @@ -337,9 +337,12 @@ static bool hist_browser__toggle_fold(struct hist_browser *browser) > { > struct hist_entry *he = browser->he_selection; > struct map_symbol *ms = browser->selection; > - struct callchain_list *cl = container_of(ms, struct callchain_list, ms); > + struct callchain_list *cl = ms ? container_of(ms, struct callchain_list, ms) : NULL;
I think this line is not needed as container_of doesn't make a pointer dereference by itself. Just checking below is enough IMHO.
Thanks, Namhyung
> bool has_children; > > + if (!ms) > + return false; > + > if (ms == &he->ms) > has_children = hist_entry__toggle_fold(he); > else > -- > 1.8.3.4 >
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