[RFC PATCH v2 1/9] perf pmu: Add from_env parameter to perf_pmu__init()
From: Ian Rogers
Date: Sat Oct 17 2026 - 14:55:20 EST
Add a boolean from_env field to struct perf_pmu initialized via
perf_pmu__init() to distinguish PMUs reconstructed from perf_env
headers from live host PMUs. Guard tp_pmu, hwmon_pmu, and drm_pmu
callbacks on !pmu->from_env so perf.data-derived PMUs do not access
host tracepoints or cast plain struct perf_pmu allocations via
container_of().
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/tests/pmu-events.c | 4 ++--
tools/perf/util/drm_pmu.c | 2 +-
tools/perf/util/hwmon_pmu.c | 2 +-
tools/perf/util/pmu.c | 33 ++++++++++++++++++---------------
tools/perf/util/pmu.h | 4 +++-
tools/perf/util/tool_pmu.c | 2 +-
6 files changed, 26 insertions(+), 21 deletions(-)
diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
index f507ce39439a..cbcc01227a76 100644
--- a/tools/perf/tests/pmu-events.c
+++ b/tools/perf/tests/pmu-events.c
@@ -514,7 +514,7 @@ static int __test_core_pmu_event_aliases(const char *pmu_name, int *count)
if (!pmu)
return -1;
- if (perf_pmu__init(pmu, PERF_PMU_TYPE_FAKE, pmu_name) != 0) {
+ if (perf_pmu__init(pmu, PERF_PMU_TYPE_FAKE, pmu_name, /*from_env=*/false) != 0) {
perf_pmu__delete(pmu);
return -1;
}
@@ -566,7 +566,7 @@ static int __test_uncore_pmu_event_aliases(struct perf_pmu_test_pmu *test_pmu)
if (!pmu)
return -1;
- if (perf_pmu__init(pmu, PERF_PMU_TYPE_FAKE, test_pmu->pmu_name) != 0) {
+ if (perf_pmu__init(pmu, PERF_PMU_TYPE_FAKE, test_pmu->pmu_name, /*from_env=*/false) != 0) {
perf_pmu__delete(pmu);
return -1;
}
diff --git a/tools/perf/util/drm_pmu.c b/tools/perf/util/drm_pmu.c
index b8badae7015c..03764efb3342 100644
--- a/tools/perf/util/drm_pmu.c
+++ b/tools/perf/util/drm_pmu.c
@@ -116,7 +116,7 @@ static struct drm_pmu *add_drm_pmu(struct list_head *pmus, char *line, size_t li
if (!drm)
return NULL;
- if (perf_pmu__init(&drm->pmu, type, name) != 0) {
+ if (perf_pmu__init(&drm->pmu, type, name, /*from_env=*/false) != 0) {
perf_pmu__delete(&drm->pmu);
return NULL;
}
diff --git a/tools/perf/util/hwmon_pmu.c b/tools/perf/util/hwmon_pmu.c
index 96aeb379e169..d9e41eb88b6d 100644
--- a/tools/perf/util/hwmon_pmu.c
+++ b/tools/perf/util/hwmon_pmu.c
@@ -365,7 +365,7 @@ struct perf_pmu *hwmon_pmu__new(struct list_head *pmus, const char *hwmon_dir,
if (!hwm)
return NULL;
- if (perf_pmu__init(&hwm->pmu, type, buf) != 0) {
+ if (perf_pmu__init(&hwm->pmu, type, buf, /*from_env=*/false) != 0) {
perf_pmu__delete(&hwm->pmu);
return NULL;
}
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 01753d5c69d1..bb2e79802def 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1188,9 +1188,10 @@ static bool aliases__equal(long key1, long key2, void *ctx __maybe_unused)
return strcasecmp((const char *)key1, (const char *)key2) == 0;
}
-int perf_pmu__init(struct perf_pmu *pmu, __u32 type, const char *name)
+int perf_pmu__init(struct perf_pmu *pmu, __u32 type, const char *name, bool from_env)
{
pmu->type = type;
+ pmu->from_env = from_env;
INIT_LIST_HEAD(&pmu->format);
INIT_LIST_HEAD(&pmu->caps);
@@ -1240,7 +1241,7 @@ struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char
if (!pmu)
return NULL;
- if (perf_pmu__init(pmu, PERF_PMU_TYPE_FAKE, name) != 0) {
+ if (perf_pmu__init(pmu, PERF_PMU_TYPE_FAKE, name, /*from_env=*/false) != 0) {
perf_pmu__delete(pmu);
return NULL;
}
@@ -2118,11 +2119,11 @@ bool perf_pmu__have_event(struct perf_pmu *pmu, const char *name)
if (perf_pmu__is_tool(pmu) && tool_pmu__skip_event(name))
return false;
if (perf_pmu__is_tracepoint(pmu))
- return tp_pmu__have_event(pmu, name);
+ return pmu->from_env ? false : tp_pmu__have_event(pmu, name);
if (perf_pmu__is_hwmon(pmu))
- return hwmon_pmu__have_event(pmu, name);
+ return pmu->from_env ? false : hwmon_pmu__have_event(pmu, name);
if (perf_pmu__is_drm(pmu))
- return drm_pmu__have_event(pmu, name);
+ return pmu->from_env ? false : drm_pmu__have_event(pmu, name);
if (perf_pmu__find_alias(pmu, name, /*load=*/ true) != NULL)
return true;
if (pmu->cpu_aliases_added || (!pmu->events_table && !pmu->is_core))
@@ -2139,11 +2140,11 @@ size_t perf_pmu__num_events(struct perf_pmu *pmu)
size_t nr;
if (perf_pmu__is_tracepoint(pmu))
- return tp_pmu__num_events(pmu);
+ return pmu->from_env ? 0 : tp_pmu__num_events(pmu);
if (perf_pmu__is_hwmon(pmu))
- return hwmon_pmu__num_events(pmu);
+ return pmu->from_env ? 0 : hwmon_pmu__num_events(pmu);
if (perf_pmu__is_drm(pmu))
- return drm_pmu__num_events(pmu);
+ return pmu->from_env ? 0 : drm_pmu__num_events(pmu);
pmu_aliases_parse(pmu);
nr = pmu->sysfs_aliases + pmu->sys_json_aliases;
@@ -2275,11 +2276,11 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
size_t size_rem;
if (perf_pmu__is_tracepoint(pmu))
- return tp_pmu__for_each_event(pmu, state, cb);
+ return pmu->from_env ? 0 : tp_pmu__for_each_event(pmu, state, cb);
if (perf_pmu__is_hwmon(pmu))
- return hwmon_pmu__for_each_event(pmu, state, cb);
+ return pmu->from_env ? 0 : hwmon_pmu__for_each_event(pmu, state, cb);
if (perf_pmu__is_drm(pmu))
- return drm_pmu__for_each_event(pmu, state, cb);
+ return pmu->from_env ? 0 : drm_pmu__for_each_event(pmu, state, cb);
pmu_aliases_parse(pmu);
pmu_add_cpu_aliases(pmu);
@@ -2784,10 +2785,12 @@ void perf_pmu__delete(struct perf_pmu *pmu)
if (!pmu)
return;
- if (perf_pmu__is_hwmon(pmu))
- hwmon_pmu__exit(pmu);
- else if (perf_pmu__is_drm(pmu))
- drm_pmu__exit(pmu);
+ if (!pmu->from_env) {
+ if (perf_pmu__is_hwmon(pmu))
+ hwmon_pmu__exit(pmu);
+ else if (perf_pmu__is_drm(pmu))
+ drm_pmu__exit(pmu);
+ }
perf_pmu__del_formats(&pmu->format);
perf_pmu__del_aliases(pmu);
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 2c8916ad073e..44212f6361c7 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -161,6 +161,8 @@ struct perf_pmu {
uint32_t cpu_common_json_aliases;
/** @sysfs_aliases_loaded: Are sysfs aliases loaded from disk? */
bool sysfs_aliases_loaded;
+ /** @from_env: Was the PMU reconstructed from a perf_env header? */
+ bool from_env;
/**
* @cpu_aliases_added: Have all json events table entries for the PMU
* been added?
@@ -345,7 +347,7 @@ int perf_pmu__pathname_scnprintf(char *buf, size_t size,
int perf_pmu__event_source_devices_fd(void);
int perf_pmu__pathname_fd(int dirfd, const char *pmu_name, const char *filename, int flags);
-int perf_pmu__init(struct perf_pmu *pmu, __u32 type, const char *name);
+int perf_pmu__init(struct perf_pmu *pmu, __u32 type, const char *name, bool from_env);
struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char *lookup_name,
bool eager_load);
struct perf_pmu *perf_pmu__create_placeholder_core_pmu(struct list_head *core_pmus);
diff --git a/tools/perf/util/tool_pmu.c b/tools/perf/util/tool_pmu.c
index d2f7591747d9..6054d5d5aece 100644
--- a/tools/perf/util/tool_pmu.c
+++ b/tools/perf/util/tool_pmu.c
@@ -714,7 +714,7 @@ struct perf_pmu *tool_pmu__new(void)
if (!tool)
return NULL;
- if (perf_pmu__init(tool, PERF_PMU_TYPE_TOOL, "tool") != 0) {
+ if (perf_pmu__init(tool, PERF_PMU_TYPE_TOOL, "tool", /*from_env=*/false) != 0) {
perf_pmu__delete(tool);
return NULL;
}
--
2.56.0.212.g129ede20d9-goog