Messages in this thread Patch in this message | | | From | Rob Herring <> | Date | Wed, 14 Sep 2022 15:08:34 -0500 | Subject | [PATCH v3 1/3] perf: Skip and warn on unknown format 'configN' attrs |
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If the kernel exposes a new perf_event_attr field in a format attr, perf will return an error stating the specified PMU can't be found. For example, a format attr with 'config3:0-63' causes an error as config3 is unknown to perf. This causes a compatibility issue between a newer kernel with older perf tool.
Before this change with a kernel adding 'config3' I get:
$ perf record -e arm_spe// -- true event syntax error: 'arm_spe//' \___ Cannot find PMU `arm_spe'. Missing kernel support? Run 'perf list' for a list of valid events
Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>]
-e, --event <event> event selector. use 'perf list' to list available events
After this change, I get:
$ perf record -e arm_spe// -- true WARNING: 'arm_spe_0' format 'inv_event_filter' requires 'perf_event_attr::config3' which is not supported by this version of perf! [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.091 MB perf.data ]
To support unknown configN formats, rework the YACC implementation to pass any config[0-9]+ format to perf_pmu__new_format() to handle with a warning.
Cc: stable@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> --- v3: - Move warning from format scanning to when PMU is selected - Add and use PERF_PMU_FORMAT_VALUE_CONFIG_END
v2: https://lore.kernel.org/all/20220909204509.2169512-1-robh@kernel.org/ - Rework YACC code to handle configN formats in C code - Add a warning when an unknown configN attr is found
v1: https://lore.kernel.org/all/20220901184709.2179309-1-robh@kernel.org/
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index f05e15acd33f..e2305fca0f95 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -215,6 +215,9 @@ __add_event(struct list_head *list, int *idx, struct perf_cpu_map *cpus = pmu ? perf_cpu_map__get(pmu->cpus) : cpu_list ? perf_cpu_map__new(cpu_list) : NULL; + if (pmu) + perf_pmu__warn_invalid_formats(pmu); + if (pmu && attr->type == PERF_TYPE_RAW) perf_pmu__warn_invalid_config(pmu, attr->config, name); diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 89655d53117a..2a0d1415dd55 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -1005,6 +1005,19 @@ static struct perf_pmu *pmu_lookup(const char *lookup_name) return NULL; } +void perf_pmu__warn_invalid_formats(struct perf_pmu *pmu) +{ + struct perf_pmu_format *format; + + list_for_each_entry(format, &pmu->format, list) + if (format->value >= PERF_PMU_FORMAT_VALUE_CONFIG_END) { + pr_warning("WARNING: '%s' format '%s' requires 'perf_event_attr::config%d'" + "which is not supported by this version of perf!\n", + pmu->name, format->name, format->value); + return; + } +} + static struct perf_pmu *pmu_find(const char *name) { struct perf_pmu *pmu; diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h index a7b0f9507510..68e15c38ae71 100644 --- a/tools/perf/util/pmu.h +++ b/tools/perf/util/pmu.h @@ -17,6 +17,7 @@ enum { PERF_PMU_FORMAT_VALUE_CONFIG, PERF_PMU_FORMAT_VALUE_CONFIG1, PERF_PMU_FORMAT_VALUE_CONFIG2, + PERF_PMU_FORMAT_VALUE_CONFIG_END, }; #define PERF_PMU_FORMAT_BITS 64 @@ -139,6 +140,7 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu); void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config, const char *name); +void perf_pmu__warn_invalid_formats(struct perf_pmu *pmu); bool perf_pmu__has_hybrid(void); int perf_pmu__match(char *pattern, char *name, char *tok); diff --git a/tools/perf/util/pmu.l b/tools/perf/util/pmu.l index a15d9fbd7c0e..58b4926cfaca 100644 --- a/tools/perf/util/pmu.l +++ b/tools/perf/util/pmu.l @@ -27,8 +27,6 @@ num_dec [0-9]+ {num_dec} { return value(10); } config { return PP_CONFIG; } -config1 { return PP_CONFIG1; } -config2 { return PP_CONFIG2; } - { return '-'; } : { return ':'; } , { return ','; } diff --git a/tools/perf/util/pmu.y b/tools/perf/util/pmu.y index bfd7e8509869..283efe059819 100644 --- a/tools/perf/util/pmu.y +++ b/tools/perf/util/pmu.y @@ -20,7 +20,7 @@ do { \ %} -%token PP_CONFIG PP_CONFIG1 PP_CONFIG2 +%token PP_CONFIG %token PP_VALUE PP_ERROR %type <num> PP_VALUE %type <bits> bit_term @@ -47,18 +47,11 @@ PP_CONFIG ':' bits $3)); } | -PP_CONFIG1 ':' bits +PP_CONFIG PP_VALUE ':' bits { ABORT_ON(perf_pmu__new_format(format, name, - PERF_PMU_FORMAT_VALUE_CONFIG1, - $3)); -} -| -PP_CONFIG2 ':' bits -{ - ABORT_ON(perf_pmu__new_format(format, name, - PERF_PMU_FORMAT_VALUE_CONFIG2, - $3)); + $2, + $4)); } bits: -- b4 0.10.0-dev
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