From: Rob Herring robh@kernel.org
commit e552b7be12ed62357df84392efa525ecb01910fb upstream.
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.
Reviewed-by: Namhyung Kim namhyung@kernel.org Signed-off-by: Rob Herring robh@kernel.org Tested-by: Leo Yan leo.yan@linaro.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Ingo Molnar mingo@redhat.com Cc: James Clark james.clark@arm.com Cc: Jiri Olsa jolsa@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Peter Zijlstra peterz@infradead.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220914-arm-perf-tool-spe1-2-v2-v4-1-83c098e6212e... Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/perf/util/parse-events.c | 3 +++ tools/perf/util/pmu.c | 17 +++++++++++++++++ tools/perf/util/pmu.h | 2 ++ tools/perf/util/pmu.l | 2 -- tools/perf/util/pmu.y | 15 ++++----------- 5 files changed, 26 insertions(+), 13 deletions(-)
--- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -254,6 +254,9 @@ __add_event(struct list_head *list, int 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);
--- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -1005,6 +1005,23 @@ err: return NULL; }
+void perf_pmu__warn_invalid_formats(struct perf_pmu *pmu) +{ + struct perf_pmu_format *format; + + /* fake pmu doesn't have format list */ + if (pmu == &perf_pmu__fake) + return; + + 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; --- 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
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); --- 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 ','; } --- 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: