Messages in this thread | | | Date | Fri, 10 Sep 2021 21:32:59 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH 2/2] perf tools: Fix hybrid config terms list corruption |
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On Thu, Sep 09, 2021 at 03:55:08PM +0300, Adrian Hunter wrote: > A config terms list was spliced twice, resulting in a never-ending loop > when the list was traversed. Fix by using list_splice_init() and copying > and freeing the lists as necessary. > > This patch also depends on patch "perf tools: Factor out > copy_config_terms() and free_config_terms()" > > Example on ADL: > > Before: > > # perf record -e '{intel_pt//,cycles/aux-sample-size=4096/pp}' uname & > # jobs > [1]+ Running perf record -e "{intel_pt//,cycles/aux-sample-size=4096/pp}" uname > # perf top -E 10 > PerfTop: 4071 irqs/sec kernel: 6.9% exact: 100.0% lost: 0/0 drop: 0/0 [4000Hz cycles], (all, 24 CPUs) > --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- > > 97.60% perf [.] __evsel__get_config_term > 0.25% [kernel] [k] kallsyms_expand_symbol.constprop.13 > 0.24% perf [.] kallsyms__parse > 0.15% [kernel] [k] _raw_spin_lock > 0.14% [kernel] [k] number > 0.13% [kernel] [k] advance_transaction > 0.08% [kernel] [k] format_decode > 0.08% perf [.] map__process_kallsym_symbol > 0.08% perf [.] rb_insert_color > 0.08% [kernel] [k] vsnprintf > exiting. > # kill %1 > > After: > > # perf record -e '{intel_pt//,cycles/aux-sample-size=4096/pp}' uname & > Linux > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.060 MB perf.data ] > # perf script | head > perf-exec 604 [001] 1827.312293: psb: psb offs: 0 ffffffffb8415e87 pt_config_start+0x37 ([kernel.kallsyms]) > perf-exec 604 1827.312293: 1 branches: ffffffffb856a3bd event_sched_in.isra.133+0xfd ([kernel.kallsyms]) => ffffffffb856a9a0 perf_pmu_nop_void+0x0 ([kernel.kallsyms]) > perf-exec 604 1827.312293: 1 branches: ffffffffb856b10e merge_sched_in+0x26e ([kernel.kallsyms]) => ffffffffb856a2c0 event_sched_in.isra.133+0x0 ([kernel.kallsyms]) > perf-exec 604 1827.312293: 1 branches: ffffffffb856a45d event_sched_in.isra.133+0x19d ([kernel.kallsyms]) => ffffffffb8568b80 perf_event_set_state.part.61+0x0 ([kernel.kallsyms]) > perf-exec 604 1827.312293: 1 branches: ffffffffb8568b86 perf_event_set_state.part.61+0x6 ([kernel.kallsyms]) => ffffffffb85662a0 perf_event_update_time+0x0 ([kernel.kallsyms]) > perf-exec 604 1827.312293: 1 branches: ffffffffb856a35c event_sched_in.isra.133+0x9c ([kernel.kallsyms]) => ffffffffb8567610 perf_log_itrace_start+0x0 ([kernel.kallsyms]) > perf-exec 604 1827.312293: 1 branches: ffffffffb856a377 event_sched_in.isra.133+0xb7 ([kernel.kallsyms]) => ffffffffb8403b40 x86_pmu_add+0x0 ([kernel.kallsyms]) > perf-exec 604 1827.312293: 1 branches: ffffffffb8403b86 x86_pmu_add+0x46 ([kernel.kallsyms]) => ffffffffb8403940 collect_events+0x0 ([kernel.kallsyms]) > perf-exec 604 1827.312293: 1 branches: ffffffffb8403a7b collect_events+0x13b ([kernel.kallsyms]) => ffffffffb8402cd0 collect_event+0x0 ([kernel.kallsyms]) > > Fixes: 94da591b1c7913 ("perf parse-events: Create two hybrid raw events") > Fixes: 9cbfa2f64c04d9 ("perf parse-events: Create two hybrid hardware events") > Fixes: 30def61f64bac5 ("perf parse-events: Create two hybrid cache events") > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > tools/perf/util/parse-events-hybrid.c | 18 +++++++++++++++--- > tools/perf/util/parse-events.c | 18 ++++++++++++------ > 2 files changed, 27 insertions(+), 9 deletions(-) > > diff --git a/tools/perf/util/parse-events-hybrid.c b/tools/perf/util/parse-events-hybrid.c > index 10160ab126f9..b234d95fb10a 100644 > --- a/tools/perf/util/parse-events-hybrid.c > +++ b/tools/perf/util/parse-events-hybrid.c > @@ -76,12 +76,16 @@ static int add_hw_hybrid(struct parse_events_state *parse_state, > int ret; > > perf_pmu__for_each_hybrid_pmu(pmu) { > + LIST_HEAD(terms); > + > if (pmu_cmp(parse_state, pmu)) > continue; > > + copy_config_terms(&terms, config_terms); > ret = create_event_hybrid(PERF_TYPE_HARDWARE, > &parse_state->idx, list, attr, name, > - config_terms, pmu); > + &terms, pmu); > + free_config_terms(&terms);
hm, why is this needed.. there's now list_splice_init &terms within create_event_hybrid call right? so there should be nothing nothing to clean
same below
> if (ret) > return ret; > } > @@ -115,11 +119,15 @@ static int add_raw_hybrid(struct parse_events_state *parse_state, > int ret; > > perf_pmu__for_each_hybrid_pmu(pmu) { > + LIST_HEAD(terms); > + > if (pmu_cmp(parse_state, pmu)) > continue; > > + copy_config_terms(&terms, config_terms); > ret = create_raw_event_hybrid(&parse_state->idx, list, attr, > - name, config_terms, pmu); > + name, &terms, pmu); > + free_config_terms(&terms); > if (ret) > return ret; > } > @@ -165,11 +173,15 @@ int parse_events__add_cache_hybrid(struct list_head *list, int *idx, > > *hybrid = true; > perf_pmu__for_each_hybrid_pmu(pmu) { > + LIST_HEAD(terms); > + > if (pmu_cmp(parse_state, pmu)) > continue; > > + copy_config_terms(&terms, config_terms); > ret = create_event_hybrid(PERF_TYPE_HW_CACHE, idx, list, > - attr, name, config_terms, pmu); > + attr, name, &terms, pmu); > + free_config_terms(&terms); > if (ret) > return ret; > } > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c > index ded5808798f9..51a2219df601 100644 > --- a/tools/perf/util/parse-events.c > +++ b/tools/perf/util/parse-events.c > @@ -387,7 +387,7 @@ __add_event(struct list_head *list, int *idx, > evsel->name = strdup(name); > > if (config_terms) > - list_splice(config_terms, &evsel->config_terms); > + list_splice_init(config_terms, &evsel->config_terms); > > if (list) > list_add_tail(&evsel->core.node, list); > @@ -535,9 +535,12 @@ int parse_events_add_cache(struct list_head *list, int *idx, > config_name ? : name, &config_terms, > &hybrid, parse_state); > if (hybrid) > - return ret; > + goto out_free_terms; > > - return add_event(list, idx, &attr, config_name ? : name, &config_terms); > + ret = add_event(list, idx, &attr, config_name ? : name, &config_terms); > +out_free_terms: > + free_config_terms(&config_terms);
.. apart from this one and below, when coming from 'goto out_free_terms' we should call free_config_terms
jirka
> + return ret; > } > > static void tracepoint_error(struct parse_events_error *e, int err, > @@ -1457,10 +1460,13 @@ int parse_events_add_numeric(struct parse_events_state *parse_state, > get_config_name(head_config), > &config_terms, &hybrid); > if (hybrid) > - return ret; > + goto out_free_terms; > > - return add_event(list, &parse_state->idx, &attr, > - get_config_name(head_config), &config_terms); > + ret = add_event(list, &parse_state->idx, &attr, > + get_config_name(head_config), &config_terms); > +out_free_terms: > + free_config_terms(&config_terms); > + return ret; > } > > int parse_events_add_tool(struct parse_events_state *parse_state, > -- > 2.17.1 >
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