perf: Skip and warn on unknown format 'configN' attrs

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@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 437389dacf483d0513e0db01e76fa7416c889076..5973f46c23755e7edf30e32f8b4c242854b740e8 100644 (file)
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -246,6 +246,9 @@ __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 74a2cafb4e8de49b75ad6fa542c9a172c084dd3e..03284059175f7f43b29826f57d13790e9a3891c3 100644 (file)
--- 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;

diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index a7b0f9507510b0de031a0398a02e3e352eaa299a..68e15c38ae710ed5f7419ebefd89b7deb2790b50 100644 (file)
--- 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 a15d9fbd7c0ed99512b0163ffe26bdb8eaf313bf..58b4926cfaca906dab6f6f85bd7f359c943f166d 100644 (file)
--- 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 0dab0ec2eff7c950cb998ee1e81e4e5883a364f5..e675d79a0274f7e8e24d65540b62443a9a4ec049 100644 (file)
--- a/tools/perf/util/pmu.y
+++ b/tools/perf/util/pmu.y
@@ -18,7 +18,7 @@ do { \
 
 %}
 
-%token PP_CONFIG PP_CONFIG1 PP_CONFIG2
+%token PP_CONFIG
 %token PP_VALUE PP_ERROR
 %type <num> PP_VALUE
 %type <bits> bit_term
@@ -45,18 +45,11 @@ 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: