| Message ID | 1441947551-48992-1-git-send-email-wangnan0@huawei.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Sep 11, 2015 at 04:59:11AM +0000, Wang Nan wrote: > 'perf top' segfaults with following operation: > > # perf top -e page-faults -p 15173 # 15173 never generate page-fault > > Then on the resulting empty interface, press right key: > > # ./perf top -e page-faults -p 11400 > perf: Segmentation fault > -------- backtrace -------- > ./perf[0x535428] > /lib64/libc.so.6(+0x3545f)[0x7f0dd360745f] > ./perf[0x531d46] > ./perf(perf_evlist__tui_browse_hists+0x96)[0x5340d6] > ./perf[0x44ba2f] > /lib64/libpthread.so.0(+0x81d0)[0x7f0dd49dc1d0] > /lib64/libc.so.6(clone+0x6c)[0x7f0dd36b90dc] > > The bug reside in perf_evsel__hists_browse() that, in the above circumstance > browser->selection can be NULL, but code after skip_annotation doesn't consider > it. > > This patch fix it by checing browser->selection before fetching > browser->selection->map and browser->selection->sym. I'm ok with this change, just a nitpick below.. > > Signed-off-by: Wang Nan <wangnan0@huawei.com> > Cc: Arnaldo Carvalho de Melo <acme@kernel.org> > Cc: Namhyung Kim <namhyung@kernel.org> > --- > tools/perf/ui/browsers/hists.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c > index e4fd40f..b00fa92 100644 > --- a/tools/perf/ui/browsers/hists.c > +++ b/tools/perf/ui/browsers/hists.c > @@ -2017,7 +2017,8 @@ skip_annotation: > &options[nr_options], dso); > nr_options += add_map_opt(browser, &actions[nr_options], > &options[nr_options], > - browser->selection->map); > + browser->selection ? > + browser->selection->map : NULL); > nr_options += add_socket_opt(browser, &actions[nr_options], > &options[nr_options], > socket); > @@ -2030,7 +2031,10 @@ skip_annotation: > nr_options += add_script_opt(browser, > &actions[nr_options], > &options[nr_options], > - NULL, browser->selection->sym); > + NULL, > + browser->selection ? > + browser->selection->sym : > + NULL); Is this really needed? IIUC browser->selection is not NULL if browser->he_selection is not NULL. Did you see a case it's NULL? Also passing a NULL thread and a NULL sym is meaningless here since it's a duplication.. Thanks, Namhyung > } > nr_options += add_script_opt(browser, &actions[nr_options], > &options[nr_options], NULL, NULL); > -- > 1.8.3.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 2015/9/12 0:22, Namhyung Kim wrote: > On Fri, Sep 11, 2015 at 04:59:11AM +0000, Wang Nan wrote: >> 'perf top' segfaults with following operation: >> >> # perf top -e page-faults -p 15173 # 15173 never generate page-fault >> >> Then on the resulting empty interface, press right key: >> >> # ./perf top -e page-faults -p 11400 >> perf: Segmentation fault >> -------- backtrace -------- >> ./perf[0x535428] >> /lib64/libc.so.6(+0x3545f)[0x7f0dd360745f] >> ./perf[0x531d46] >> ./perf(perf_evlist__tui_browse_hists+0x96)[0x5340d6] >> ./perf[0x44ba2f] >> /lib64/libpthread.so.0(+0x81d0)[0x7f0dd49dc1d0] >> /lib64/libc.so.6(clone+0x6c)[0x7f0dd36b90dc] >> >> The bug reside in perf_evsel__hists_browse() that, in the above circumstance >> browser->selection can be NULL, but code after skip_annotation doesn't consider >> it. >> >> This patch fix it by checing browser->selection before fetching >> browser->selection->map and browser->selection->sym. > I'm ok with this change, just a nitpick below.. > > >> Signed-off-by: Wang Nan <wangnan0@huawei.com> >> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> >> Cc: Namhyung Kim <namhyung@kernel.org> >> --- >> tools/perf/ui/browsers/hists.c | 8 ++++++-- >> 1 file changed, 6 insertions(+), 2 deletions(-) >> >> diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c >> index e4fd40f..b00fa92 100644 >> --- a/tools/perf/ui/browsers/hists.c >> +++ b/tools/perf/ui/browsers/hists.c >> @@ -2017,7 +2017,8 @@ skip_annotation: >> &options[nr_options], dso); >> nr_options += add_map_opt(browser, &actions[nr_options], >> &options[nr_options], >> - browser->selection->map); >> + browser->selection ? >> + browser->selection->map : NULL); >> nr_options += add_socket_opt(browser, &actions[nr_options], >> &options[nr_options], >> socket); >> @@ -2030,7 +2031,10 @@ skip_annotation: >> nr_options += add_script_opt(browser, >> &actions[nr_options], >> &options[nr_options], >> - NULL, browser->selection->sym); >> + NULL, >> + browser->selection ? >> + browser->selection->sym : >> + NULL); > Is this really needed? IIUC browser->selection is not NULL if > browser->he_selection is not NULL. Did you see a case it's NULL? > Also passing a NULL thread and a NULL sym is meaningless here since > it's a duplication.. Actually I didn't see the case when browser->he_selection is not NULL but browser->selection is NULL. I add the testing only for safety reason because we have if (browser->selection == NULL) goto skip_annotation; So I guess we'd better to check browser->selection in the codeblock leading by skip_annotation, so if someone breaks the assumption the code still work. But yes, we can add the checker back when the assumption *does* be broken. Currently let's add a comment here for code readers. Please have a look for v2 patch. Thank you. > Thanks, > Namhyung > > >> } >> nr_options += add_script_opt(browser, &actions[nr_options], >> &options[nr_options], NULL, NULL); >> -- >> 1.8.3.4 >> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c index e4fd40f..b00fa92 100644 --- a/tools/perf/ui/browsers/hists.c +++ b/tools/perf/ui/browsers/hists.c @@ -2017,7 +2017,8 @@ skip_annotation: &options[nr_options], dso); nr_options += add_map_opt(browser, &actions[nr_options], &options[nr_options], - browser->selection->map); + browser->selection ? + browser->selection->map : NULL); nr_options += add_socket_opt(browser, &actions[nr_options], &options[nr_options], socket); @@ -2030,7 +2031,10 @@ skip_annotation: nr_options += add_script_opt(browser, &actions[nr_options], &options[nr_options], - NULL, browser->selection->sym); + NULL, + browser->selection ? + browser->selection->sym : + NULL); } nr_options += add_script_opt(browser, &actions[nr_options], &options[nr_options], NULL, NULL);
'perf top' segfaults with following operation: # perf top -e page-faults -p 15173 # 15173 never generate page-fault Then on the resulting empty interface, press right key: # ./perf top -e page-faults -p 11400 perf: Segmentation fault -------- backtrace -------- ./perf[0x535428] /lib64/libc.so.6(+0x3545f)[0x7f0dd360745f] ./perf[0x531d46] ./perf(perf_evlist__tui_browse_hists+0x96)[0x5340d6] ./perf[0x44ba2f] /lib64/libpthread.so.0(+0x81d0)[0x7f0dd49dc1d0] /lib64/libc.so.6(clone+0x6c)[0x7f0dd36b90dc] The bug reside in perf_evsel__hists_browse() that, in the above circumstance browser->selection can be NULL, but code after skip_annotation doesn't consider it. This patch fix it by checing browser->selection before fetching browser->selection->map and browser->selection->sym. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> --- tools/perf/ui/browsers/hists.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)