Messages in this thread | | | Date | Fri, 17 Jan 2020 10:34:09 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v6 2/2] perf parse: Copy string to perf_evsel_config_term |
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Em Fri, Jan 17, 2020 at 01:52:51PM +0800, Leo Yan escreveu: > perf with CoreSight fails to record trace data with command: > > perf record -e cs_etm/@tmc_etr0/u --per-thread ls > failed to set sink "" on event cs_etm/@tmc_etr0/u with 21 (Is a > directory)/perf/ > > This failure is root caused with the commit 1dc925568f01 ("perf > parse: Add a deep delete for parse event terms"). > > The log shows, cs_etm fails to parse the sink attribution; cs_etm event > relies on the event configuration to pass sink name, but the event > specific configuration data cannot be passed properly with flow: > > get_config_terms() > ADD_CONFIG_TERM(DRV_CFG, term->val.str); > __t->val.str = term->val.str; > `> __t->val.str is assigned to term->val.str; > > parse_events_terms__purge() > parse_events_term__delete() > zfree(&term->val.str); > `> term->val.str is freed and assigned to NULL pointer; > > cs_etm_set_sink_attr() > sink = __t->val.str; > `> sink string has been freed. > > To fix this issue, in the function get_config_terms(), this patch > changes to use strdup() for allocation a new duplicate string rather > than directly assignment string pointer. > > This patch addes a new field 'free_str' in the data structure > perf_evsel_config_term; 'free_str' is set to true when the union is used > as a string pointer; thus it can tell perf_evsel__free_config_terms() to > free the string. > > Fixes: 1dc925568f01 ("perf parse: Add a deep delete for parse event terms") > Suggested-by: Jiri Olsa <jolsa@kernel.org> > Signed-off-by: Leo Yan <leo.yan@linaro.org> > Acked-by: Jiri Olsa <jolsa@kernel.org> > --- > tools/perf/util/evsel.c | 2 ++ > tools/perf/util/evsel_config.h | 1 + > tools/perf/util/parse-events.c | 7 ++++++- > 3 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 549abd43816f..6fe9e28180e5 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -1265,6 +1265,8 @@ static void perf_evsel__free_config_terms(struct evsel *evsel) > > list_for_each_entry_safe(term, h, &evsel->config_terms, list) { > list_del_init(&term->list); > + if (term->free_str) > + free(term->val.str);
I'm replacing this with zfree, so that we can catch possible bugs where term gets used after freed, just like you do below, in ADD_CONFIG_TERM_STR()
Thanks,
> free(term); > } > } > diff --git a/tools/perf/util/evsel_config.h b/tools/perf/util/evsel_config.h > index b4a65201e4f7..e026ab67b008 100644 > --- a/tools/perf/util/evsel_config.h > +++ b/tools/perf/util/evsel_config.h > @@ -32,6 +32,7 @@ enum evsel_term_type { > struct perf_evsel_config_term { > struct list_head list; > enum evsel_term_type type; > + bool free_str; > union { > u64 period; > u64 freq; > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c > index f59f3c8da473..c01ba6f8fdad 100644 > --- a/tools/perf/util/parse-events.c > +++ b/tools/perf/util/parse-events.c > @@ -1240,7 +1240,12 @@ do { \ > #define ADD_CONFIG_TERM_STR(__type, __val) \ > do { \ > ADD_CONFIG_TERM(__type); \ > - __t->val.str = __val; \ > + __t->val.str = strdup(__val); \ > + if (!__t->val.str) { \ > + zfree(&__t); \ > + return -ENOMEM; \ > + } \ > + __t->free_str = true; \ > } while (0) > > struct parse_events_term *term; > -- > 2.17.1
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