Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 725 insertions, 0 deletions

diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
new file mode 100644
index 000000000..25f31a174
--- /dev/null
+++ b/tools/perf/util/stat.c
@@ -0,0 +1,725 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "stat.h"
+
+#include <errno.h>
+#include <inttypes.h>
+#include <math.h>
+#include <string.h>
+
+#include <linux/err.h>
+#include <linux/zalloc.h>
+
+#include "counts.h"
+#include "cpumap.h"
+#include "debug.h"
+#include "evlist.h"
+#include "evsel.h"
+#include "hashmap.h"
+#include "header.h"
+#include "pmu.h"
+#include "session.h"
+#include "target.h"
+#include "thread_map.h"
+
+void update_stats(struct stats *stats, u64 val)
+{
+	double delta;
+
+	stats->n++;
+	delta = val - stats->mean;
+	stats->mean += delta / stats->n;
+	stats->M2 += delta*(val - stats->mean);
+
+	if (val > stats->max)
+		stats->max = val;
+
+	if (val < stats->min)
+		stats->min = val;
+}
+
+double avg_stats(struct stats *stats)
+{
+	return stats->mean;
+}
+
+/*
+ * http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
+ *
+ *       (\Sum n_i^2) - ((\Sum n_i)^2)/n
+ * s^2 = -------------------------------
+ *                  n - 1
+ *
+ * http://en.wikipedia.org/wiki/Stddev
+ *
+ * The std dev of the mean is related to the std dev by:
+ *
+ *             s
+ * s_mean = -------
+ *          sqrt(n)
+ *
+ */
+double stddev_stats(struct stats *stats)
+{
+	double variance, variance_mean;
+
+	if (stats->n < 2)
+		return 0.0;
+
+	variance = stats->M2 / (stats->n - 1);
+	variance_mean = variance / stats->n;
+
+	return sqrt(variance_mean);
+}
+
+double rel_stddev_stats(double stddev, double avg)
+{
+	double pct = 0.0;
+
+	if (avg)
+		pct = 100.0 * stddev/avg;
+
+	return pct;
+}
+
+static void evsel__reset_aggr_stats(struct evsel *evsel)
+{
+	struct perf_stat_evsel *ps = evsel->stats;
+	struct perf_stat_aggr *aggr = ps->aggr;
+
+	if (aggr)
+		memset(aggr, 0, sizeof(*aggr) * ps->nr_aggr);
+}
+
+static void evsel__reset_stat_priv(struct evsel *evsel)
+{
+	struct perf_stat_evsel *ps = evsel->stats;
+
+	init_stats(&ps->res_stats);
+	evsel__reset_aggr_stats(evsel);
+}
+
+static int evsel__alloc_aggr_stats(struct evsel *evsel, int nr_aggr)
+{
+	struct perf_stat_evsel *ps = evsel->stats;
+
+	if (ps == NULL)
+		return 0;
+
+	ps->nr_aggr = nr_aggr;
+	ps->aggr = calloc(nr_aggr, sizeof(*ps->aggr));
+	if (ps->aggr == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+int evlist__alloc_aggr_stats(struct evlist *evlist, int nr_aggr)
+{
+	struct evsel *evsel;
+
+	evlist__for_each_entry(evlist, evsel) {
+		if (evsel__alloc_aggr_stats(evsel, nr_aggr) < 0)
+			return -1;
+	}
+	return 0;
+}
+
+static int evsel__alloc_stat_priv(struct evsel *evsel, int nr_aggr)
+{
+	struct perf_stat_evsel *ps;
+
+	ps = zalloc(sizeof(*ps));
+	if (ps == NULL)
+		return -ENOMEM;
+
+	evsel->stats = ps;
+
+	if (nr_aggr && evsel__alloc_aggr_stats(evsel, nr_aggr) < 0) {
+		evsel->stats = NULL;
+		free(ps);
+		return -ENOMEM;
+	}
+
+	evsel__reset_stat_priv(evsel);
+	return 0;
+}
+
+static void evsel__free_stat_priv(struct evsel *evsel)
+{
+	struct perf_stat_evsel *ps = evsel->stats;
+
+	if (ps) {
+		zfree(&ps->aggr);
+		zfree(&ps->group_data);
+	}
+	zfree(&evsel->stats);
+}
+
+static int evsel__alloc_prev_raw_counts(struct evsel *evsel)
+{
+	int cpu_map_nr = evsel__nr_cpus(evsel);
+	int nthreads = perf_thread_map__nr(evsel->core.threads);
+	struct perf_counts *counts;
+
+	counts = perf_counts__new(cpu_map_nr, nthreads);
+	if (counts)
+		evsel->prev_raw_counts = counts;
+
+	return counts ? 0 : -ENOMEM;
+}
+
+static void evsel__free_prev_raw_counts(struct evsel *evsel)
+{
+	perf_counts__delete(evsel->prev_raw_counts);
+	evsel->prev_raw_counts = NULL;
+}
+
+static void evsel__reset_prev_raw_counts(struct evsel *evsel)
+{
+	if (evsel->prev_raw_counts)
+		perf_counts__reset(evsel->prev_raw_counts);
+}
+
+static int evsel__alloc_stats(struct evsel *evsel, int nr_aggr, bool alloc_raw)
+{
+	if (evsel__alloc_stat_priv(evsel, nr_aggr) < 0 ||
+	    evsel__alloc_counts(evsel) < 0 ||
+	    (alloc_raw && evsel__alloc_prev_raw_counts(evsel) < 0))
+		return -ENOMEM;
+
+	return 0;
+}
+
+int evlist__alloc_stats(struct perf_stat_config *config,
+			struct evlist *evlist, bool alloc_raw)
+{
+	struct evsel *evsel;
+	int nr_aggr = 0;
+
+	if (config && config->aggr_map)
+		nr_aggr = config->aggr_map->nr;
+
+	evlist__for_each_entry(evlist, evsel) {
+		if (evsel__alloc_stats(evsel, nr_aggr, alloc_raw))
+			goto out_free;
+	}
+
+	return 0;
+
+out_free:
+	evlist__free_stats(evlist);
+	return -1;
+}
+
+void evlist__free_stats(struct evlist *evlist)
+{
+	struct evsel *evsel;
+
+	evlist__for_each_entry(evlist, evsel) {
+		evsel__free_stat_priv(evsel);
+		evsel__free_counts(evsel);
+		evsel__free_prev_raw_counts(evsel);
+	}
+}
+
+void evlist__reset_stats(struct evlist *evlist)
+{
+	struct evsel *evsel;
+
+	evlist__for_each_entry(evlist, evsel) {
+		evsel__reset_stat_priv(evsel);
+		evsel__reset_counts(evsel);
+	}
+}
+
+void evlist__reset_aggr_stats(struct evlist *evlist)
+{
+	struct evsel *evsel;
+
+	evlist__for_each_entry(evlist, evsel)
+		evsel__reset_aggr_stats(evsel);
+}
+
+void evlist__reset_prev_raw_counts(struct evlist *evlist)
+{
+	struct evsel *evsel;
+
+	evlist__for_each_entry(evlist, evsel)
+		evsel__reset_prev_raw_counts(evsel);
+}
+
+static void evsel__copy_prev_raw_counts(struct evsel *evsel)
+{
+	int nthreads = perf_thread_map__nr(evsel->core.threads);
+
+	for (int thread = 0; thread < nthreads; thread++) {
+		unsigned int idx;
+
+		perf_cpu_map__for_each_idx(idx, evsel__cpus(evsel)) {
+			*perf_counts(evsel->counts, idx, thread) =
+				*perf_counts(evsel->prev_raw_counts, idx, thread);
+		}
+	}
+}
+
+void evlist__copy_prev_raw_counts(struct evlist *evlist)
+{
+	struct evsel *evsel;
+
+	evlist__for_each_entry(evlist, evsel)
+		evsel__copy_prev_raw_counts(evsel);
+}
+
+static void evsel__copy_res_stats(struct evsel *evsel)
+{
+	struct perf_stat_evsel *ps = evsel->stats;
+
+	/*
+	 * For GLOBAL aggregation mode, it updates the counts for each run
+	 * in the evsel->stats.res_stats.  See perf_stat_process_counter().
+	 */
+	*ps->aggr[0].counts.values = avg_stats(&ps->res_stats);
+}
+
+void evlist__copy_res_stats(struct perf_stat_config *config, struct evlist *evlist)
+{
+	struct evsel *evsel;
+
+	if (config->aggr_mode != AGGR_GLOBAL)
+		return;
+
+	evlist__for_each_entry(evlist, evsel)
+		evsel__copy_res_stats(evsel);
+}
+
+static size_t pkg_id_hash(long __key, void *ctx __maybe_unused)
+{
+	uint64_t *key = (uint64_t *) __key;
+
+	return *key & 0xffffffff;
+}
+
+static bool pkg_id_equal(long __key1, long __key2, void *ctx __maybe_unused)
+{
+	uint64_t *key1 = (uint64_t *) __key1;
+	uint64_t *key2 = (uint64_t *) __key2;
+
+	return *key1 == *key2;
+}
+
+static int check_per_pkg(struct evsel *counter, struct perf_counts_values *vals,
+			 int cpu_map_idx, bool *skip)
+{
+	struct hashmap *mask = counter->per_pkg_mask;
+	struct perf_cpu_map *cpus = evsel__cpus(counter);
+	struct perf_cpu cpu = perf_cpu_map__cpu(cpus, cpu_map_idx);
+	int s, d, ret = 0;
+	uint64_t *key;
+
+	*skip = false;
+
+	if (!counter->per_pkg)
+		return 0;
+
+	if (perf_cpu_map__is_any_cpu_or_is_empty(cpus))
+		return 0;
+
+	if (!mask) {
+		mask = hashmap__new(pkg_id_hash, pkg_id_equal, NULL);
+		if (IS_ERR(mask))
+			return -ENOMEM;
+
+		counter->per_pkg_mask = mask;
+	}
+
+	/*
+	 * we do not consider an event that has not run as a good
+	 * instance to mark a package as used (skip=1). Otherwise
+	 * we may run into a situation where the first CPU in a package
+	 * is not running anything, yet the second is, and this function
+	 * would mark the package as used after the first CPU and would
+	 * not read the values from the second CPU.
+	 */
+	if (!(vals->run && vals->ena))
+		return 0;
+
+	s = cpu__get_socket_id(cpu);
+	if (s < 0)
+		return -1;
+
+	/*
+	 * On multi-die system, die_id > 0. On no-die system, die_id = 0.
+	 * We use hashmap(socket, die) to check the used socket+die pair.
+	 */
+	d = cpu__get_die_id(cpu);
+	if (d < 0)
+		return -1;
+
+	key = malloc(sizeof(*key));
+	if (!key)
+		return -ENOMEM;
+
+	*key = (uint64_t)d << 32 | s;
+	if (hashmap__find(mask, key, NULL)) {
+		*skip = true;
+		free(key);
+	} else
+		ret = hashmap__add(mask, key, 1);
+
+	return ret;
+}
+
+static bool evsel__count_has_error(struct evsel *evsel,
+				   struct perf_counts_values *count,
+				   struct perf_stat_config *config)
+{
+	/* the evsel was failed already */
+	if (evsel->err || evsel->counts->scaled == -1)
+		return true;
+
+	/* this is meaningful for CPU aggregation modes only */
+	if (config->aggr_mode == AGGR_GLOBAL)
+		return false;
+
+	/* it's considered ok when it actually ran */
+	if (count->ena != 0 && count->run != 0)
+		return false;
+
+	return true;
+}
+
+static int
+process_counter_values(struct perf_stat_config *config, struct evsel *evsel,
+		       int cpu_map_idx, int thread,
+		       struct perf_counts_values *count)
+{
+	struct perf_stat_evsel *ps = evsel->stats;
+	static struct perf_counts_values zero;
+	bool skip = false;
+
+	if (check_per_pkg(evsel, count, cpu_map_idx, &skip)) {
+		pr_err("failed to read per-pkg counter\n");
+		return -1;
+	}
+
+	if (skip)
+		count = &zero;
+
+	if (!evsel->snapshot)
+		evsel__compute_deltas(evsel, cpu_map_idx, thread, count);
+	perf_counts_values__scale(count, config->scale, NULL);
+
+	if (config->aggr_mode == AGGR_THREAD) {
+		struct perf_counts_values *aggr_counts = &ps->aggr[thread].counts;
+
+		/*
+		 * Skip value 0 when enabling --per-thread globally,
+		 * otherwise too many 0 output.
+		 */
+		if (count->val == 0 && config->system_wide)
+			return 0;
+
+		ps->aggr[thread].nr++;
+
+		aggr_counts->val += count->val;
+		aggr_counts->ena += count->ena;
+		aggr_counts->run += count->run;
+		return 0;
+	}
+
+	if (ps->aggr) {
+		struct perf_cpu cpu = perf_cpu_map__cpu(evsel->core.cpus, cpu_map_idx);
+		struct aggr_cpu_id aggr_id = config->aggr_get_id(config, cpu);
+		struct perf_stat_aggr *ps_aggr;
+		int i;
+
+		for (i = 0; i < ps->nr_aggr; i++) {
+			if (!aggr_cpu_id__equal(&aggr_id, &config->aggr_map->map[i]))
+				continue;
+
+			ps_aggr = &ps->aggr[i];
+			ps_aggr->nr++;
+
+			/*
+			 * When any result is bad, make them all to give consistent output
+			 * in interval mode.  But per-task counters can have 0 enabled time
+			 * when some tasks are idle.
+			 */
+			if (evsel__count_has_error(evsel, count, config) && !ps_aggr->failed) {
+				ps_aggr->counts.val = 0;
+				ps_aggr->counts.ena = 0;
+				ps_aggr->counts.run = 0;
+				ps_aggr->failed = true;
+			}
+
+			if (!ps_aggr->failed) {
+				ps_aggr->counts.val += count->val;
+				ps_aggr->counts.ena += count->ena;
+				ps_aggr->counts.run += count->run;
+			}
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int process_counter_maps(struct perf_stat_config *config,
+				struct evsel *counter)
+{
+	int nthreads = perf_thread_map__nr(counter->core.threads);
+	int ncpus = evsel__nr_cpus(counter);
+	int idx, thread;
+
+	for (thread = 0; thread < nthreads; thread++) {
+		for (idx = 0; idx < ncpus; idx++) {
+			if (process_counter_values(config, counter, idx, thread,
+						   perf_counts(counter->counts, idx, thread)))
+				return -1;
+		}
+	}
+
+	return 0;
+}
+
+int perf_stat_process_counter(struct perf_stat_config *config,
+			      struct evsel *counter)
+{
+	struct perf_stat_evsel *ps = counter->stats;
+	u64 *count;
+	int ret;
+
+	if (counter->per_pkg)
+		evsel__zero_per_pkg(counter);
+
+	ret = process_counter_maps(config, counter);
+	if (ret)
+		return ret;
+
+	if (config->aggr_mode != AGGR_GLOBAL)
+		return 0;
+
+	/*
+	 * GLOBAL aggregation mode only has a single aggr counts,
+	 * so we can use ps->aggr[0] as the actual output.
+	 */
+	count = ps->aggr[0].counts.values;
+	update_stats(&ps->res_stats, *count);
+
+	if (verbose > 0) {
+		fprintf(config->output, "%s: %" PRIu64 " %" PRIu64 " %" PRIu64 "\n",
+			evsel__name(counter), count[0], count[1], count[2]);
+	}
+
+	return 0;
+}
+
+static int evsel__merge_aggr_counters(struct evsel *evsel, struct evsel *alias)
+{
+	struct perf_stat_evsel *ps_a = evsel->stats;
+	struct perf_stat_evsel *ps_b = alias->stats;
+	int i;
+
+	if (ps_a->aggr == NULL && ps_b->aggr == NULL)
+		return 0;
+
+	if (ps_a->nr_aggr != ps_b->nr_aggr) {
+		pr_err("Unmatched aggregation mode between aliases\n");
+		return -1;
+	}
+
+	for (i = 0; i < ps_a->nr_aggr; i++) {
+		struct perf_counts_values *aggr_counts_a = &ps_a->aggr[i].counts;
+		struct perf_counts_values *aggr_counts_b = &ps_b->aggr[i].counts;
+
+		ps_a->aggr[i].nr += ps_b->aggr[i].nr;
+
+		aggr_counts_a->val += aggr_counts_b->val;
+		aggr_counts_a->ena += aggr_counts_b->ena;
+		aggr_counts_a->run += aggr_counts_b->run;
+	}
+
+	return 0;
+}
+
+static void evsel__merge_aliases(struct evsel *evsel)
+{
+	struct evlist *evlist = evsel->evlist;
+	struct evsel *alias;
+
+	alias = list_prepare_entry(evsel, &(evlist__core(evlist)->entries), core.node);
+	list_for_each_entry_continue(alias, &evlist__core(evlist)->entries, core.node) {
+		if (alias->first_wildcard_match == evsel) {
+			/* Merge the same events on different PMUs. */
+			evsel__merge_aggr_counters(evsel, alias);
+		}
+	}
+}
+
+static bool evsel__should_merge_hybrid(const struct evsel *evsel,
+				       const struct perf_stat_config *config)
+{
+	return config->hybrid_merge && evsel__is_hybrid(evsel);
+}
+
+static void evsel__merge_stats(struct evsel *evsel, struct perf_stat_config *config)
+{
+	if (!evsel->pmu || !evsel->pmu->is_core || evsel__should_merge_hybrid(evsel, config))
+		evsel__merge_aliases(evsel);
+}
+
+/* merge the same uncore and hybrid events if requested */
+void perf_stat_merge_counters(struct perf_stat_config *config, struct evlist *evlist)
+{
+	struct evsel *evsel;
+
+	if (config->aggr_mode == AGGR_NONE)
+		return;
+
+	evlist__for_each_entry(evlist, evsel)
+		evsel__merge_stats(evsel, config);
+}
+
+static void evsel__update_percore_stats(struct evsel *evsel, struct aggr_cpu_id *core_id)
+{
+	struct perf_stat_evsel *ps = evsel->stats;
+	struct perf_counts_values counts = { 0, };
+	struct aggr_cpu_id id;
+	struct perf_cpu cpu;
+	unsigned int idx;
+
+	/* collect per-core counts */
+	perf_cpu_map__for_each_cpu(cpu, idx, evsel->core.cpus) {
+		struct perf_stat_aggr *aggr = &ps->aggr[idx];
+
+		id = aggr_cpu_id__core(cpu, NULL);
+		if (!aggr_cpu_id__equal(core_id, &id))
+			continue;
+
+		counts.val += aggr->counts.val;
+		counts.ena += aggr->counts.ena;
+		counts.run += aggr->counts.run;
+	}
+
+	/* update aggregated per-core counts for each CPU */
+	perf_cpu_map__for_each_cpu(cpu, idx, evsel->core.cpus) {
+		struct perf_stat_aggr *aggr = &ps->aggr[idx];
+
+		id = aggr_cpu_id__core(cpu, NULL);
+		if (!aggr_cpu_id__equal(core_id, &id))
+			continue;
+
+		aggr->counts.val = counts.val;
+		aggr->counts.ena = counts.ena;
+		aggr->counts.run = counts.run;
+
+		aggr->used = true;
+	}
+}
+
+/* we have an aggr_map for cpu, but want to aggregate the counters per-core */
+static void evsel__process_percore(struct evsel *evsel)
+{
+	struct perf_stat_evsel *ps = evsel->stats;
+	struct aggr_cpu_id core_id;
+	struct perf_cpu cpu;
+	unsigned int idx;
+
+	if (!evsel->percore)
+		return;
+
+	perf_cpu_map__for_each_cpu(cpu, idx, evsel->core.cpus) {
+		struct perf_stat_aggr *aggr = &ps->aggr[idx];
+
+		if (aggr->used)
+			continue;
+
+		core_id = aggr_cpu_id__core(cpu, NULL);
+		evsel__update_percore_stats(evsel, &core_id);
+	}
+}
+
+/* process cpu stats on per-core events */
+void perf_stat_process_percore(struct perf_stat_config *config, struct evlist *evlist)
+{
+	struct evsel *evsel;
+
+	if (config->aggr_mode != AGGR_NONE)
+		return;
+
+	evlist__for_each_entry(evlist, evsel)
+		evsel__process_percore(evsel);
+}
+
+int perf_event__process_stat_event(const struct perf_tool *tool __maybe_unused,
+				   struct perf_session *session,
+				   union perf_event *event)
+{
+	struct perf_counts_values count, *ptr;
+	struct perf_record_stat *st = &event->stat;
+	struct evsel *counter;
+	int cpu_map_idx;
+
+	count.val = st->val;
+	count.ena = st->ena;
+	count.run = st->run;
+
+	counter = evlist__id2evsel(session->evlist, st->id);
+	if (!counter) {
+		pr_err("Failed to resolve counter for stat event.\n");
+		return -EINVAL;
+	}
+	cpu_map_idx = perf_cpu_map__idx(evsel__cpus(counter), (struct perf_cpu){.cpu = st->cpu});
+	if (cpu_map_idx == -1) {
+		pr_err("Invalid CPU %d for event %s.\n", st->cpu, evsel__name(counter));
+		return -EINVAL;
+	}
+	ptr = perf_counts(counter->counts, cpu_map_idx, st->thread);
+	if (ptr == NULL) {
+		pr_err("Failed to find perf count for CPU %d thread %d on event %s.\n",
+			st->cpu, st->thread, evsel__name(counter));
+		return -EINVAL;
+	}
+	*ptr = count;
+	counter->supported = true;
+	return 0;
+}
+
+size_t perf_event__fprintf_stat(union perf_event *event, FILE *fp)
+{
+	struct perf_record_stat *st = (struct perf_record_stat *)event;
+	size_t ret;
+
+	ret  = fprintf(fp, "\n... id %" PRI_lu64 ", cpu %d, thread %d\n",
+		       st->id, st->cpu, st->thread);
+	ret += fprintf(fp, "... value %" PRI_lu64 ", enabled %" PRI_lu64 ", running %" PRI_lu64 "\n",
+		       st->val, st->ena, st->run);
+
+	return ret;
+}
+
+size_t perf_event__fprintf_stat_round(union perf_event *event, FILE *fp)
+{
+	struct perf_record_stat_round *rd = (struct perf_record_stat_round *)event;
+	size_t ret;
+
+	ret = fprintf(fp, "\n... time %" PRI_lu64 ", type %s\n", rd->time,
+		      rd->type == PERF_STAT_ROUND_TYPE__FINAL ? "FINAL" : "INTERVAL");
+
+	return ret;
+}
+
+size_t perf_event__fprintf_stat_config(union perf_event *event, FILE *fp)
+{
+	struct perf_stat_config sc = {};
+	size_t ret;
+
+	perf_event__read_stat_config(&sc, &event->stat_config);
+
+	ret  = fprintf(fp, "\n");
+	ret += fprintf(fp, "... aggr_mode %d\n", sc.aggr_mode);
+	ret += fprintf(fp, "... scale     %d\n", sc.scale);
+	ret += fprintf(fp, "... interval  %u\n", sc.interval);
+
+	return ret;
+}