* [PATCH v1] perf parse-events: Avoid segv if PMU lookup fails for legacy cache terms
@ 2023-07-12 6:52 Ian Rogers
2023-07-12 19:27 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 3+ messages in thread
From: Ian Rogers @ 2023-07-12 6:52 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Mark Rutland, Alexander Shishkin, Jiri Olsa, Namhyung Kim,
Ian Rogers, Adrian Hunter, Kan Liang, Zhengjun Xing,
linux-perf-users, linux-kernel
libfuzzer found the following command could segv:
```
$ perf stat -e cpu/L2,L2/ true
```
This is because the L2 term rewrites the perf_event_attr type to
PERF_TYPE_HW_CACHE which then fails the PMU lookup for the second
legacy cache term.
The new failure is consistent with repeated hardware terms:
```
$ perf stat -e cpu/L2,L2/ true
event syntax error: 'cpu/L2,L2/'
\___ Failed to find PMU for type 3
Initial error:
event syntax error: 'cpu/L2,L2/'
\___ Failed to find PMU for type 3
Run 'perf list' for a list of valid events
Usage: perf stat [<options>] [<command>]
-e, --event <event> event selector. use 'perf list' to list available events
$ perf stat -e cpu/cycles,cycles/ true
event syntax error: 'cpu/cycles,cycles/'
\___ Failed to find PMU for type 0
Initial error:
event syntax error: 'cpu/cycles,cycles/'
\___ Failed to find PMU for type 0
Run 'perf list' for a list of valid events
Usage: perf stat [<options>] [<command>]
-e, --event <event> event selector. use 'perf list' to list available events
```
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/parse-events.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 5dcfbf316bf6..acde097e327c 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1216,6 +1216,14 @@ static int config_term_pmu(struct perf_event_attr *attr,
if (term->type_term == PARSE_EVENTS__TERM_TYPE_LEGACY_CACHE) {
const struct perf_pmu *pmu = perf_pmus__find_by_type(attr->type);
+ if (!pmu) {
+ char *err_str;
+
+ if (asprintf(&err_str, "Failed to find PMU for type %d", attr->type) >= 0)
+ parse_events_error__handle(err, term->err_term,
+ err_str, /*help=*/NULL);
+ return -EINVAL;
+ }
if (perf_pmu__supports_legacy_cache(pmu)) {
attr->type = PERF_TYPE_HW_CACHE;
return parse_events__decode_legacy_cache(term->config, pmu->type,
--
2.41.0.390.g38632f3daf-goog
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v1] perf parse-events: Avoid segv if PMU lookup fails for legacy cache terms 2023-07-12 6:52 [PATCH v1] perf parse-events: Avoid segv if PMU lookup fails for legacy cache terms Ian Rogers @ 2023-07-12 19:27 ` Arnaldo Carvalho de Melo 2023-07-12 20:29 ` Ian Rogers 0 siblings, 1 reply; 3+ messages in thread From: Arnaldo Carvalho de Melo @ 2023-07-12 19:27 UTC (permalink / raw) To: Ian Rogers Cc: Peter Zijlstra, Ingo Molnar, Mark Rutland, Alexander Shishkin, Jiri Olsa, Namhyung Kim, Adrian Hunter, Kan Liang, Zhengjun Xing, linux-perf-users, linux-kernel Em Tue, Jul 11, 2023 at 11:52:50PM -0700, Ian Rogers escreveu: > libfuzzer found the following command could segv: > ``` > $ perf stat -e cpu/L2,L2/ true > ``` > This is because the L2 term rewrites the perf_event_attr type to > PERF_TYPE_HW_CACHE which then fails the PMU lookup for the second > legacy cache term. > > The new failure is consistent with repeated hardware terms: > ``` > $ perf stat -e cpu/L2,L2/ true > event syntax error: 'cpu/L2,L2/' > \___ Failed to find PMU for type 3 > > Initial error: > event syntax error: 'cpu/L2,L2/' > \___ Failed to find PMU for type 3 > Run 'perf list' for a list of valid events > > Usage: perf stat [<options>] [<command>] > > -e, --event <event> event selector. use 'perf list' to list available events > $ perf stat -e cpu/cycles,cycles/ true > event syntax error: 'cpu/cycles,cycles/' > \___ Failed to find PMU for type 0 > > Initial error: > event syntax error: 'cpu/cycles,cycles/' > \___ Failed to find PMU for type 0 > Run 'perf list' for a list of valid events > > Usage: perf stat [<options>] [<command>] > > -e, --event <event> event selector. use 'perf list' to list available events > ``` I added the Fixes as requested: Fixes: 6fd1e5191591f9d5 ("perf parse-events: Support PMUs for legacy cache events") Please check if the patch below helps a bit giving more info to the user, but still a bit cryptic: ⬢[acme@toolbox perf-tools]$ perf stat -e cpu/L2,L2/ true event syntax error: 'cpu/L2,L2/' \___ Failed to find PMU for perf_event_attr.type 3 (PERF_TYPE_HW_CACHE) Initial error: event syntax error: 'cpu/L2,L2/' \___ Failed to find PMU for perf_event_attr.type 3 (PERF_TYPE_HW_CACHE) Run 'perf list' for a list of valid events Usage: perf stat [<options>] [<command>] -e, --event <event> event selector. use 'perf list' to list available events ⬢[acme@toolbox perf-tools]$ And the other case is needs more patching, so better leave this for 6.6. ⬢[acme@toolbox perf-tools]$ perf stat -e cpu/cycles,cycles/ true event syntax error: 'cpu/cycles,cycles/' \___ Failed to find PMU for type 0 Initial error: event syntax error: 'cpu/cycles,cycles/' \___ Failed to find PMU for type 0 Run 'perf list' for a list of valid events Usage: perf stat [<options>] [<command>] -e, --event <event> event selector. use 'perf list' to list available events ⬢[acme@toolbox perf-tools]$ - Arnaldo diff --git a/tools/perf/util/evsel_fprintf.h b/tools/perf/util/evsel_fprintf.h index c8a9fac2f2ddc0f2..044612774a962020 100644 --- a/tools/perf/util/evsel_fprintf.h +++ b/tools/perf/util/evsel_fprintf.h @@ -4,6 +4,7 @@ #include <stdio.h> #include <stdbool.h> +#include <linux/types.h> struct evsel; @@ -45,6 +46,8 @@ int sample__fprintf_sym(struct perf_sample *sample, struct addr_location *al, typedef int (*attr__fprintf_f)(FILE *, const char *, const char *, void *); +const char *stringify_perf_type_id(u64 value); + int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr, attr__fprintf_f attr__fprintf, void *priv); #endif // __PERF_EVSEL_H diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index acde097e327cce8c..8678469cf974070a 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -25,6 +25,7 @@ #include "asm/bug.h" #include "util/parse-branch-options.h" #include "util/evsel_config.h" +#include "util/evsel_fprintf.h" #include "util/event.h" #include "util/bpf-filter.h" #include "util/util.h" @@ -1219,9 +1220,11 @@ static int config_term_pmu(struct perf_event_attr *attr, if (!pmu) { char *err_str; - if (asprintf(&err_str, "Failed to find PMU for type %d", attr->type) >= 0) + if (asprintf(&err_str, "Failed to find PMU for perf_event_attr.type %d (%s)", attr->type, + stringify_perf_type_id(attr->type)) >= 0) { parse_events_error__handle(err, term->err_term, err_str, /*help=*/NULL); + } return -EINVAL; } if (perf_pmu__supports_legacy_cache(pmu)) { diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c index 2247991451f3aa1b..ce97371eda027271 100644 --- a/tools/perf/util/perf_event_attr_fprintf.c +++ b/tools/perf/util/perf_event_attr_fprintf.c @@ -74,7 +74,7 @@ static void __p_read_format(char *buf, size_t size, u64 value) } #define ENUM_ID_TO_STR_CASE(x) case x: return (#x); -static const char *stringify_perf_type_id(u64 value) +const char *stringify_perf_type_id(u64 value) { switch (value) { ENUM_ID_TO_STR_CASE(PERF_TYPE_HARDWARE) ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v1] perf parse-events: Avoid segv if PMU lookup fails for legacy cache terms 2023-07-12 19:27 ` Arnaldo Carvalho de Melo @ 2023-07-12 20:29 ` Ian Rogers 0 siblings, 0 replies; 3+ messages in thread From: Ian Rogers @ 2023-07-12 20:29 UTC (permalink / raw) To: Arnaldo Carvalho de Melo Cc: Peter Zijlstra, Ingo Molnar, Mark Rutland, Alexander Shishkin, Jiri Olsa, Namhyung Kim, Adrian Hunter, Kan Liang, Zhengjun Xing, linux-perf-users, linux-kernel On Wed, Jul 12, 2023 at 12:27 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > Em Tue, Jul 11, 2023 at 11:52:50PM -0700, Ian Rogers escreveu: > > libfuzzer found the following command could segv: > > ``` > > $ perf stat -e cpu/L2,L2/ true > > ``` > > This is because the L2 term rewrites the perf_event_attr type to > > PERF_TYPE_HW_CACHE which then fails the PMU lookup for the second > > legacy cache term. > > > > The new failure is consistent with repeated hardware terms: > > ``` > > $ perf stat -e cpu/L2,L2/ true > > event syntax error: 'cpu/L2,L2/' > > \___ Failed to find PMU for type 3 > > > > Initial error: > > event syntax error: 'cpu/L2,L2/' > > \___ Failed to find PMU for type 3 > > Run 'perf list' for a list of valid events > > > > Usage: perf stat [<options>] [<command>] > > > > -e, --event <event> event selector. use 'perf list' to list available events > > $ perf stat -e cpu/cycles,cycles/ true > > event syntax error: 'cpu/cycles,cycles/' > > \___ Failed to find PMU for type 0 > > > > Initial error: > > event syntax error: 'cpu/cycles,cycles/' > > \___ Failed to find PMU for type 0 > > Run 'perf list' for a list of valid events > > > > Usage: perf stat [<options>] [<command>] > > > > -e, --event <event> event selector. use 'perf list' to list available events > > ``` > > I added the Fixes as requested: > > Fixes: 6fd1e5191591f9d5 ("perf parse-events: Support PMUs for legacy cache events") > > Please check if the patch below helps a bit giving more info to the > user, but still a bit cryptic: > > ⬢[acme@toolbox perf-tools]$ perf stat -e cpu/L2,L2/ true > event syntax error: 'cpu/L2,L2/' > \___ Failed to find PMU for perf_event_attr.type 3 (PERF_TYPE_HW_CACHE) > > Initial error: > event syntax error: 'cpu/L2,L2/' > \___ Failed to find PMU for perf_event_attr.type 3 (PERF_TYPE_HW_CACHE) > Run 'perf list' for a list of valid events > > Usage: perf stat [<options>] [<command>] > > -e, --event <event> event selector. use 'perf list' to list available events > ⬢[acme@toolbox perf-tools]$ > > And the other case is needs more patching, so better leave this for 6.6. > > > ⬢[acme@toolbox perf-tools]$ perf stat -e cpu/cycles,cycles/ true > event syntax error: 'cpu/cycles,cycles/' > \___ Failed to find PMU for type 0 > > Initial error: > event syntax error: 'cpu/cycles,cycles/' > \___ Failed to find PMU for type 0 > Run 'perf list' for a list of valid events > > Usage: perf stat [<options>] [<command>] > > -e, --event <event> event selector. use 'perf list' to list available events > ⬢[acme@toolbox perf-tools]$ The stringify looks good. Something strange is the value there is a u64 by type is a __u32 in the perf_event_attr. Thanks! Ian > - Arnaldo > > diff --git a/tools/perf/util/evsel_fprintf.h b/tools/perf/util/evsel_fprintf.h > index c8a9fac2f2ddc0f2..044612774a962020 100644 > --- a/tools/perf/util/evsel_fprintf.h > +++ b/tools/perf/util/evsel_fprintf.h > @@ -4,6 +4,7 @@ > > #include <stdio.h> > #include <stdbool.h> > +#include <linux/types.h> > > struct evsel; > > @@ -45,6 +46,8 @@ int sample__fprintf_sym(struct perf_sample *sample, struct addr_location *al, > > typedef int (*attr__fprintf_f)(FILE *, const char *, const char *, void *); > > +const char *stringify_perf_type_id(u64 value); > + > int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr, > attr__fprintf_f attr__fprintf, void *priv); > #endif // __PERF_EVSEL_H > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c > index acde097e327cce8c..8678469cf974070a 100644 > --- a/tools/perf/util/parse-events.c > +++ b/tools/perf/util/parse-events.c > @@ -25,6 +25,7 @@ > #include "asm/bug.h" > #include "util/parse-branch-options.h" > #include "util/evsel_config.h" > +#include "util/evsel_fprintf.h" > #include "util/event.h" > #include "util/bpf-filter.h" > #include "util/util.h" > @@ -1219,9 +1220,11 @@ static int config_term_pmu(struct perf_event_attr *attr, > if (!pmu) { > char *err_str; > > - if (asprintf(&err_str, "Failed to find PMU for type %d", attr->type) >= 0) > + if (asprintf(&err_str, "Failed to find PMU for perf_event_attr.type %d (%s)", attr->type, > + stringify_perf_type_id(attr->type)) >= 0) { > parse_events_error__handle(err, term->err_term, > err_str, /*help=*/NULL); > + } > return -EINVAL; > } > if (perf_pmu__supports_legacy_cache(pmu)) { > diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c > index 2247991451f3aa1b..ce97371eda027271 100644 > --- a/tools/perf/util/perf_event_attr_fprintf.c > +++ b/tools/perf/util/perf_event_attr_fprintf.c > @@ -74,7 +74,7 @@ static void __p_read_format(char *buf, size_t size, u64 value) > } > > #define ENUM_ID_TO_STR_CASE(x) case x: return (#x); > -static const char *stringify_perf_type_id(u64 value) > +const char *stringify_perf_type_id(u64 value) > { > switch (value) { > ENUM_ID_TO_STR_CASE(PERF_TYPE_HARDWARE) ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-07-12 20:29 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2023-07-12 6:52 [PATCH v1] perf parse-events: Avoid segv if PMU lookup fails for legacy cache terms Ian Rogers 2023-07-12 19:27 ` Arnaldo Carvalho de Melo 2023-07-12 20:29 ` Ian Rogers
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