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>
This commit is contained in:
Rob Herring 2022-10-04 14:12:35 -05:00 committed by Arnaldo Carvalho de Melo
parent 0cef141e86
commit e552b7be12
5 changed files with 26 additions and 13 deletions

View File

@ -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);

View File

@ -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;

View File

@ -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);

View File

@ -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 ','; }

View File

@ -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: