[PATCH v2 02/13] perf pmu: Allow hardcoded terms to be applied to attributes

From: Ian Rogers
Date: Thu Sep 12 2024 - 15:04:23 EST


Hard coded terms like "config=10" are skipped by perf_pmu__config
assuming they were already applied to a perf_event_attr by parse
event's config_attr function. When doing a reverse number to name
lookup in perf_pmu__name_from_config, as the hardcoded terms aren't
applied the config value is incorrect leading to misses or false
matches. Fix this by adding a parameter to have perf_pmu__config apply
hardcoded terms too (not just in parse event's config_term_common).

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/arch/x86/util/intel-pt.c | 3 +-
tools/perf/tests/pmu.c | 3 +-
tools/perf/util/parse-events.c | 4 ++-
tools/perf/util/pmu.c | 56 ++++++++++++++++++++++++-----
tools/perf/util/pmu.h | 4 ++-
5 files changed, 58 insertions(+), 12 deletions(-)

diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
index ea510a7486b1..8f235d8b67b6 100644
--- a/tools/perf/arch/x86/util/intel-pt.c
+++ b/tools/perf/arch/x86/util/intel-pt.c
@@ -75,7 +75,8 @@ static int intel_pt_parse_terms_with_default(const struct perf_pmu *pmu,
goto out_free;

attr.config = *config;
- err = perf_pmu__config_terms(pmu, &attr, &terms, /*zero=*/true, /*err=*/NULL);
+ err = perf_pmu__config_terms(pmu, &attr, &terms, /*zero=*/true, /*apply_hardcoded=*/false,
+ /*err=*/NULL);
if (err)
goto out_free;

diff --git a/tools/perf/tests/pmu.c b/tools/perf/tests/pmu.c
index be18506f6a24..6a681e3fb552 100644
--- a/tools/perf/tests/pmu.c
+++ b/tools/perf/tests/pmu.c
@@ -176,7 +176,8 @@ static int test__pmu_format(struct test_suite *test __maybe_unused, int subtest
}

memset(&attr, 0, sizeof(attr));
- ret = perf_pmu__config_terms(pmu, &attr, &terms, /*zero=*/false, /*err=*/NULL);
+ ret = perf_pmu__config_terms(pmu, &attr, &terms, /*zero=*/false,
+ /*apply_hardcoded=*/false, /*err=*/NULL);
if (ret) {
pr_err("perf_pmu__config_terms failed");
goto err_out;
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 9a8be1e46d67..26bbc6f603ab 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1537,7 +1537,9 @@ static int parse_events_add_pmu(struct parse_events_state *parse_state,
return -ENOMEM;
}

- if (perf_pmu__config(pmu, &attr, &parsed_terms, parse_state->error)) {
+ /* Skip configuring hard coded terms that were applied by config_attr. */
+ if (perf_pmu__config(pmu, &attr, &parsed_terms, /*apply_hardcoded=*/false,
+ parse_state->error)) {
free_config_terms(&config_terms);
parse_events_terms__exit(&parsed_terms);
return -EINVAL;
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 779db2ac06f0..c020fc34b635 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1366,7 +1366,8 @@ static int pmu_config_term(const struct perf_pmu *pmu,
struct perf_event_attr *attr,
struct parse_events_term *term,
struct parse_events_terms *head_terms,
- bool zero, struct parse_events_error *err)
+ bool zero, bool apply_hardcoded,
+ struct parse_events_error *err)
{
struct perf_pmu_format *format;
__u64 *vp;
@@ -1380,11 +1381,46 @@ static int pmu_config_term(const struct perf_pmu *pmu,
return 0;

/*
- * Hardcoded terms should be already in, so nothing
- * to be done for them.
+ * Hardcoded terms are generally handled in event parsing, which
+ * traditionally have had to handle not having a PMU. An alias may
+ * have hard coded config values, optionally apply them below.
*/
- if (parse_events__is_hardcoded_term(term))
+ if (parse_events__is_hardcoded_term(term)) {
+ /* Config terms set all bits in the config. */
+ DECLARE_BITMAP(bits, PERF_PMU_FORMAT_BITS);
+
+ if (!apply_hardcoded)
+ return 0;
+
+ bitmap_fill(bits, PERF_PMU_FORMAT_BITS);
+
+ switch (term->type_term) {
+ case PARSE_EVENTS__TERM_TYPE_CONFIG:
+ assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
+ pmu_format_value(bits, term->val.num, &attr->config, zero);
+ break;
+ case PARSE_EVENTS__TERM_TYPE_CONFIG1:
+ assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
+ pmu_format_value(bits, term->val.num, &attr->config1, zero);
+ break;
+ case PARSE_EVENTS__TERM_TYPE_CONFIG2:
+ assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
+ pmu_format_value(bits, term->val.num, &attr->config2, zero);
+ break;
+ case PARSE_EVENTS__TERM_TYPE_CONFIG3:
+ assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
+ pmu_format_value(bits, term->val.num, &attr->config3, zero);
+ break;
+ case PARSE_EVENTS__TERM_TYPE_USER: /* Not hardcoded. */
+ return -EINVAL;
+ case PARSE_EVENTS__TERM_TYPE_NAME ... PARSE_EVENTS__TERM_TYPE_HARDWARE:
+ /* Skip non-config terms. */
+ break;
+ default:
+ break;
+ }
return 0;
+ }

format = pmu_find_format(&pmu->format, term->config);
if (!format) {
@@ -1487,12 +1523,13 @@ static int pmu_config_term(const struct perf_pmu *pmu,
int perf_pmu__config_terms(const struct perf_pmu *pmu,
struct perf_event_attr *attr,
struct parse_events_terms *terms,
- bool zero, struct parse_events_error *err)
+ bool zero, bool apply_hardcoded,
+ struct parse_events_error *err)
{
struct parse_events_term *term;

list_for_each_entry(term, &terms->terms, list) {
- if (pmu_config_term(pmu, attr, term, terms, zero, err))
+ if (pmu_config_term(pmu, attr, term, terms, zero, apply_hardcoded, err))
return -EINVAL;
}

@@ -1506,6 +1543,7 @@ int perf_pmu__config_terms(const struct perf_pmu *pmu,
*/
int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
struct parse_events_terms *head_terms,
+ bool apply_hardcoded,
struct parse_events_error *err)
{
bool zero = !!pmu->perf_event_attr_init_default;
@@ -1514,7 +1552,7 @@ int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
if (perf_pmu__is_fake(pmu))
return 0;

- return perf_pmu__config_terms(pmu, attr, head_terms, zero, err);
+ return perf_pmu__config_terms(pmu, attr, head_terms, zero, apply_hardcoded, err);
}

static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
@@ -2279,7 +2317,9 @@ const char *perf_pmu__name_from_config(struct perf_pmu *pmu, u64 config)
pmu_add_cpu_aliases(pmu);
list_for_each_entry(event, &pmu->aliases, list) {
struct perf_event_attr attr = {.config = 0,};
- int ret = perf_pmu__config(pmu, &attr, &event->terms, NULL);
+
+ int ret = perf_pmu__config(pmu, &attr, &event->terms, /*apply_hardcoded=*/true,
+ /*err=*/NULL);

if (ret == 0 && config == attr.config)
return event->name;
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 4397c48ad569..af7532ca7fb1 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -206,11 +206,13 @@ typedef int (*pmu_format_callback)(void *state, const char *name, int config,
void pmu_add_sys_aliases(struct perf_pmu *pmu);
int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
struct parse_events_terms *head_terms,
+ bool apply_hardcoded,
struct parse_events_error *error);
int perf_pmu__config_terms(const struct perf_pmu *pmu,
struct perf_event_attr *attr,
struct parse_events_terms *terms,
- bool zero, struct parse_events_error *error);
+ bool zero, bool apply_hardcoded,
+ struct parse_events_error *error);
__u64 perf_pmu__format_bits(struct perf_pmu *pmu, const char *name);
int perf_pmu__format_type(struct perf_pmu *pmu, const char *name);
int perf_pmu__check_alias(struct perf_pmu *pmu, struct parse_events_terms *head_terms,
--
2.46.0.662.g92d0881bb0-goog