Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

10 files changed, 1427 insertions, 0 deletions

diff --git a/tools/perf/util/bpf_skel/.gitignore b/tools/perf/util/bpf_skel/.gitignore
new file mode 100644
index 000000000..5263e9e6c
--- /dev/null
+++ b/tools/perf/util/bpf_skel/.gitignore
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+.tmp
+*.skel.h
\ No newline at end of file
diff --git a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c
new file mode 100644
index 000000000..6a438e010
--- /dev/null
+++ b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2021 Facebook
+// Copyright (c) 2021 Google
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#define MAX_LEVELS  10  // max cgroup hierarchy level: arbitrary
+#define MAX_EVENTS  32  // max events per cgroup: arbitrary
+
+// NOTE: many of map and global data will be modified before loading
+//       from the userspace (perf tool) using the skeleton helpers.
+
+// single set of global perf events to measure
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(int));
+	__uint(max_entries, 1);
+} events SEC(".maps");
+
+// from cgroup id to event index
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u64));
+	__uint(value_size, sizeof(__u32));
+	__uint(max_entries, 1);
+} cgrp_idx SEC(".maps");
+
+// per-cpu event snapshots to calculate delta
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+} prev_readings SEC(".maps");
+
+// aggregated event values for each cgroup (per-cpu)
+// will be read from the user-space
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+} cgrp_readings SEC(".maps");
+
+/* new kernel cgroup definition */
+struct cgroup___new {
+	int level;
+	struct cgroup *ancestors[];
+} __attribute__((preserve_access_index));
+
+/* old kernel cgroup definition */
+struct cgroup___old {
+	int level;
+	u64 ancestor_ids[];
+} __attribute__((preserve_access_index));
+
+const volatile __u32 num_events = 1;
+const volatile __u32 num_cpus = 1;
+
+int enabled = 0;
+int use_cgroup_v2 = 0;
+int perf_subsys_id = -1;
+
+static inline __u64 get_cgroup_v1_ancestor_id(struct cgroup *cgrp, int level)
+{
+	/* recast pointer to capture new type for compiler */
+	struct cgroup___new *cgrp_new = (void *)cgrp;
+
+	if (bpf_core_field_exists(cgrp_new->ancestors)) {
+		return BPF_CORE_READ(cgrp_new, ancestors[level], kn, id);
+	} else {
+		/* recast pointer to capture old type for compiler */
+		struct cgroup___old *cgrp_old = (void *)cgrp;
+
+		return BPF_CORE_READ(cgrp_old, ancestor_ids[level]);
+	}
+}
+
+static inline int get_cgroup_v1_idx(__u32 *cgrps, int size)
+{
+	struct task_struct *p = (void *)bpf_get_current_task();
+	struct cgroup *cgrp;
+	register int i = 0;
+	__u32 *elem;
+	int level;
+	int cnt;
+
+	if (perf_subsys_id == -1) {
+#if __has_builtin(__builtin_preserve_enum_value)
+		perf_subsys_id = bpf_core_enum_value(enum cgroup_subsys_id,
+						     perf_event_cgrp_id);
+#else
+		perf_subsys_id = perf_event_cgrp_id;
+#endif
+	}
+	cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_subsys_id], cgroup);
+	level = BPF_CORE_READ(cgrp, level);
+
+	for (cnt = 0; i < MAX_LEVELS; i++) {
+		__u64 cgrp_id;
+
+		if (i > level)
+			break;
+
+		// convert cgroup-id to a map index
+		cgrp_id = get_cgroup_v1_ancestor_id(cgrp, i);
+		elem = bpf_map_lookup_elem(&cgrp_idx, &cgrp_id);
+		if (!elem)
+			continue;
+
+		cgrps[cnt++] = *elem;
+		if (cnt == size)
+			break;
+	}
+
+	return cnt;
+}
+
+static inline int get_cgroup_v2_idx(__u32 *cgrps, int size)
+{
+	register int i = 0;
+	__u32 *elem;
+	int cnt;
+
+	for (cnt = 0; i < MAX_LEVELS; i++) {
+		__u64 cgrp_id = bpf_get_current_ancestor_cgroup_id(i);
+
+		if (cgrp_id == 0)
+			break;
+
+		// convert cgroup-id to a map index
+		elem = bpf_map_lookup_elem(&cgrp_idx, &cgrp_id);
+		if (!elem)
+			continue;
+
+		cgrps[cnt++] = *elem;
+		if (cnt == size)
+			break;
+	}
+
+	return cnt;
+}
+
+static int bperf_cgroup_count(void)
+{
+	register __u32 idx = 0;  // to have it in a register to pass BPF verifier
+	register int c = 0;
+	struct bpf_perf_event_value val, delta, *prev_val, *cgrp_val;
+	__u32 cpu = bpf_get_smp_processor_id();
+	__u32 cgrp_idx[MAX_LEVELS];
+	int cgrp_cnt;
+	__u32 key, cgrp;
+	long err;
+
+	if (use_cgroup_v2)
+		cgrp_cnt = get_cgroup_v2_idx(cgrp_idx, MAX_LEVELS);
+	else
+		cgrp_cnt = get_cgroup_v1_idx(cgrp_idx, MAX_LEVELS);
+
+	for ( ; idx < MAX_EVENTS; idx++) {
+		if (idx == num_events)
+			break;
+
+		// XXX: do not pass idx directly (for verifier)
+		key = idx;
+		// this is per-cpu array for diff
+		prev_val = bpf_map_lookup_elem(&prev_readings, &key);
+		if (!prev_val) {
+			val.counter = val.enabled = val.running = 0;
+			bpf_map_update_elem(&prev_readings, &key, &val, BPF_ANY);
+
+			prev_val = bpf_map_lookup_elem(&prev_readings, &key);
+			if (!prev_val)
+				continue;
+		}
+
+		// read from global perf_event array
+		key = idx * num_cpus + cpu;
+		err = bpf_perf_event_read_value(&events, key, &val, sizeof(val));
+		if (err)
+			continue;
+
+		if (enabled) {
+			delta.counter = val.counter - prev_val->counter;
+			delta.enabled = val.enabled - prev_val->enabled;
+			delta.running = val.running - prev_val->running;
+
+			for (c = 0; c < MAX_LEVELS; c++) {
+				if (c == cgrp_cnt)
+					break;
+
+				cgrp = cgrp_idx[c];
+
+				// aggregate the result by cgroup
+				key = cgrp * num_events + idx;
+				cgrp_val = bpf_map_lookup_elem(&cgrp_readings, &key);
+				if (cgrp_val) {
+					cgrp_val->counter += delta.counter;
+					cgrp_val->enabled += delta.enabled;
+					cgrp_val->running += delta.running;
+				} else {
+					bpf_map_update_elem(&cgrp_readings, &key,
+							    &delta, BPF_ANY);
+				}
+			}
+		}
+
+		*prev_val = val;
+	}
+	return 0;
+}
+
+// This will be attached to cgroup-switches event for each cpu
+SEC("perf_event")
+int BPF_PROG(on_cgrp_switch)
+{
+	return bperf_cgroup_count();
+}
+
+SEC("raw_tp/sched_switch")
+int BPF_PROG(trigger_read)
+{
+	return bperf_cgroup_count();
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
diff --git a/tools/perf/util/bpf_skel/bperf_follower.bpf.c b/tools/perf/util/bpf_skel/bperf_follower.bpf.c
new file mode 100644
index 000000000..f19399853
--- /dev/null
+++ b/tools/perf/util/bpf_skel/bperf_follower.bpf.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2021 Facebook
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include "bperf_u.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+	__uint(max_entries, 1);
+} diff_readings SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+	__uint(max_entries, 1);
+} accum_readings SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u32));
+} filter SEC(".maps");
+
+enum bperf_filter_type type = 0;
+int enabled = 0;
+
+SEC("fexit/XXX")
+int BPF_PROG(fexit_XXX)
+{
+	struct bpf_perf_event_value *diff_val, *accum_val;
+	__u32 filter_key, zero = 0;
+	__u32 *accum_key;
+
+	if (!enabled)
+		return 0;
+
+	switch (type) {
+	case BPERF_FILTER_GLOBAL:
+		accum_key = &zero;
+		goto do_add;
+	case BPERF_FILTER_CPU:
+		filter_key = bpf_get_smp_processor_id();
+		break;
+	case BPERF_FILTER_PID:
+		filter_key = bpf_get_current_pid_tgid() & 0xffffffff;
+		break;
+	case BPERF_FILTER_TGID:
+		filter_key = bpf_get_current_pid_tgid() >> 32;
+		break;
+	default:
+		return 0;
+	}
+
+	accum_key = bpf_map_lookup_elem(&filter, &filter_key);
+	if (!accum_key)
+		return 0;
+
+do_add:
+	diff_val = bpf_map_lookup_elem(&diff_readings, &zero);
+	if (!diff_val)
+		return 0;
+
+	accum_val = bpf_map_lookup_elem(&accum_readings, accum_key);
+	if (!accum_val)
+		return 0;
+
+	accum_val->counter += diff_val->counter;
+	accum_val->enabled += diff_val->enabled;
+	accum_val->running += diff_val->running;
+
+	return 0;
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
diff --git a/tools/perf/util/bpf_skel/bperf_leader.bpf.c b/tools/perf/util/bpf_skel/bperf_leader.bpf.c
new file mode 100644
index 000000000..e2a2d4cd7
--- /dev/null
+++ b/tools/perf/util/bpf_skel/bperf_leader.bpf.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2021 Facebook
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(int));
+	__uint(map_flags, BPF_F_PRESERVE_ELEMS);
+} events SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+	__uint(max_entries, 1);
+} prev_readings SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+	__uint(max_entries, 1);
+} diff_readings SEC(".maps");
+
+SEC("raw_tp/sched_switch")
+int BPF_PROG(on_switch)
+{
+	struct bpf_perf_event_value val, *prev_val, *diff_val;
+	__u32 key = bpf_get_smp_processor_id();
+	__u32 zero = 0;
+	long err;
+
+	prev_val = bpf_map_lookup_elem(&prev_readings, &zero);
+	if (!prev_val)
+		return 0;
+
+	diff_val = bpf_map_lookup_elem(&diff_readings, &zero);
+	if (!diff_val)
+		return 0;
+
+	err = bpf_perf_event_read_value(&events, key, &val, sizeof(val));
+	if (err)
+		return 0;
+
+	diff_val->counter = val.counter - prev_val->counter;
+	diff_val->enabled = val.enabled - prev_val->enabled;
+	diff_val->running = val.running - prev_val->running;
+	*prev_val = val;
+	return 0;
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
diff --git a/tools/perf/util/bpf_skel/bperf_u.h b/tools/perf/util/bpf_skel/bperf_u.h
new file mode 100644
index 000000000..1ce0c2c90
--- /dev/null
+++ b/tools/perf/util/bpf_skel/bperf_u.h
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2021 Facebook
+
+#ifndef __BPERF_STAT_U_H
+#define __BPERF_STAT_U_H
+
+enum bperf_filter_type {
+	BPERF_FILTER_GLOBAL = 1,
+	BPERF_FILTER_CPU,
+	BPERF_FILTER_PID,
+	BPERF_FILTER_TGID,
+};
+
+#endif /* __BPERF_STAT_U_H */
diff --git a/tools/perf/util/bpf_skel/bpf_prog_profiler.bpf.c b/tools/perf/util/bpf_skel/bpf_prog_profiler.bpf.c
new file mode 100644
index 000000000..97037d3b3
--- /dev/null
+++ b/tools/perf/util/bpf_skel/bpf_prog_profiler.bpf.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2020 Facebook
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+/* map of perf event fds, num_cpu * num_metric entries */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(int));
+} events SEC(".maps");
+
+/* readings at fentry */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+	__uint(max_entries, 1);
+} fentry_readings SEC(".maps");
+
+/* accumulated readings */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+	__uint(max_entries, 1);
+} accum_readings SEC(".maps");
+
+const volatile __u32 num_cpu = 1;
+
+SEC("fentry/XXX")
+int BPF_PROG(fentry_XXX)
+{
+	__u32 key = bpf_get_smp_processor_id();
+	struct bpf_perf_event_value *ptr;
+	__u32 zero = 0;
+	long err;
+
+	/* look up before reading, to reduce error */
+	ptr = bpf_map_lookup_elem(&fentry_readings, &zero);
+	if (!ptr)
+		return 0;
+
+	err = bpf_perf_event_read_value(&events, key, ptr, sizeof(*ptr));
+	if (err)
+		return 0;
+
+	return 0;
+}
+
+static inline void
+fexit_update_maps(struct bpf_perf_event_value *after)
+{
+	struct bpf_perf_event_value *before, diff;
+	__u32 zero = 0;
+
+	before = bpf_map_lookup_elem(&fentry_readings, &zero);
+	/* only account samples with a valid fentry_reading */
+	if (before && before->counter) {
+		struct bpf_perf_event_value *accum;
+
+		diff.counter = after->counter - before->counter;
+		diff.enabled = after->enabled - before->enabled;
+		diff.running = after->running - before->running;
+
+		accum = bpf_map_lookup_elem(&accum_readings, &zero);
+		if (accum) {
+			accum->counter += diff.counter;
+			accum->enabled += diff.enabled;
+			accum->running += diff.running;
+		}
+	}
+}
+
+SEC("fexit/XXX")
+int BPF_PROG(fexit_XXX)
+{
+	struct bpf_perf_event_value reading;
+	__u32 cpu = bpf_get_smp_processor_id();
+	int err;
+
+	/* read all events before updating the maps, to reduce error */
+	err = bpf_perf_event_read_value(&events, cpu, &reading, sizeof(reading));
+	if (err)
+		return 0;
+
+	fexit_update_maps(&reading);
+	return 0;
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
diff --git a/tools/perf/util/bpf_skel/func_latency.bpf.c b/tools/perf/util/bpf_skel/func_latency.bpf.c
new file mode 100644
index 000000000..9d01e3af7
--- /dev/null
+++ b/tools/perf/util/bpf_skel/func_latency.bpf.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2021 Google
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+// This should be in sync with "util/ftrace.h"
+#define NUM_BUCKET  22
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u64));
+	__uint(value_size, sizeof(__u64));
+	__uint(max_entries, 10000);
+} functime SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u8));
+	__uint(max_entries, 1);
+} cpu_filter SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u8));
+	__uint(max_entries, 1);
+} task_filter SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u64));
+	__uint(max_entries, NUM_BUCKET);
+} latency SEC(".maps");
+
+
+int enabled = 0;
+int has_cpu = 0;
+int has_task = 0;
+int use_nsec = 0;
+
+SEC("kprobe/func")
+int BPF_PROG(func_begin)
+{
+	__u64 key, now;
+
+	if (!enabled)
+		return 0;
+
+	key = bpf_get_current_pid_tgid();
+
+	if (has_cpu) {
+		__u32 cpu = bpf_get_smp_processor_id();
+		__u8 *ok;
+
+		ok = bpf_map_lookup_elem(&cpu_filter, &cpu);
+		if (!ok)
+			return 0;
+	}
+
+	if (has_task) {
+		__u32 pid = key & 0xffffffff;
+		__u8 *ok;
+
+		ok = bpf_map_lookup_elem(&task_filter, &pid);
+		if (!ok)
+			return 0;
+	}
+
+	now = bpf_ktime_get_ns();
+
+	// overwrite timestamp for nested functions
+	bpf_map_update_elem(&functime, &key, &now, BPF_ANY);
+	return 0;
+}
+
+SEC("kretprobe/func")
+int BPF_PROG(func_end)
+{
+	__u64 tid;
+	__u64 *start;
+	__u64 cmp_base = use_nsec ? 1 : 1000;
+
+	if (!enabled)
+		return 0;
+
+	tid = bpf_get_current_pid_tgid();
+
+	start = bpf_map_lookup_elem(&functime, &tid);
+	if (start) {
+		__s64 delta = bpf_ktime_get_ns() - *start;
+		__u32 key;
+		__u64 *hist;
+
+		bpf_map_delete_elem(&functime, &tid);
+
+		if (delta < 0)
+			return 0;
+
+		// calculate index using delta
+		for (key = 0; key < (NUM_BUCKET - 1); key++) {
+			if (delta < (cmp_base << key))
+				break;
+		}
+
+		hist = bpf_map_lookup_elem(&latency, &key);
+		if (!hist)
+			return 0;
+
+		*hist += 1;
+	}
+
+	return 0;
+}
diff --git a/tools/perf/util/bpf_skel/kwork_trace.bpf.c b/tools/perf/util/bpf_skel/kwork_trace.bpf.c
new file mode 100644
index 000000000..063c124e0
--- /dev/null
+++ b/tools/perf/util/bpf_skel/kwork_trace.bpf.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2022, Huawei
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define KWORK_COUNT 100
+#define MAX_KWORKNAME 128
+
+/*
+ * This should be in sync with "util/kwork.h"
+ */
+enum kwork_class_type {
+	KWORK_CLASS_IRQ,
+	KWORK_CLASS_SOFTIRQ,
+	KWORK_CLASS_WORKQUEUE,
+	KWORK_CLASS_MAX,
+};
+
+struct work_key {
+	__u32 type;
+	__u32 cpu;
+	__u64 id;
+};
+
+struct report_data {
+	__u64 nr;
+	__u64 total_time;
+	__u64 max_time;
+	__u64 max_time_start;
+	__u64 max_time_end;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(struct work_key));
+	__uint(value_size, MAX_KWORKNAME);
+	__uint(max_entries, KWORK_COUNT);
+} perf_kwork_names SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(struct work_key));
+	__uint(value_size, sizeof(__u64));
+	__uint(max_entries, KWORK_COUNT);
+} perf_kwork_time SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(struct work_key));
+	__uint(value_size, sizeof(struct report_data));
+	__uint(max_entries, KWORK_COUNT);
+} perf_kwork_report SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u8));
+	__uint(max_entries, 1);
+} perf_kwork_cpu_filter SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, MAX_KWORKNAME);
+	__uint(max_entries, 1);
+} perf_kwork_name_filter SEC(".maps");
+
+int enabled = 0;
+int has_cpu_filter = 0;
+int has_name_filter = 0;
+
+static __always_inline int local_strncmp(const char *s1,
+					 unsigned int sz, const char *s2)
+{
+	int ret = 0;
+	unsigned int i;
+
+	for (i = 0; i < sz; i++) {
+		ret = (unsigned char)s1[i] - (unsigned char)s2[i];
+		if (ret || !s1[i] || !s2[i])
+			break;
+	}
+
+	return ret;
+}
+
+static __always_inline int trace_event_match(struct work_key *key, char *name)
+{
+	__u8 *cpu_val;
+	char *name_val;
+	__u32 zero = 0;
+	__u32 cpu = bpf_get_smp_processor_id();
+
+	if (!enabled)
+		return 0;
+
+	if (has_cpu_filter) {
+		cpu_val = bpf_map_lookup_elem(&perf_kwork_cpu_filter, &cpu);
+		if (!cpu_val)
+			return 0;
+	}
+
+	if (has_name_filter && (name != NULL)) {
+		name_val = bpf_map_lookup_elem(&perf_kwork_name_filter, &zero);
+		if (name_val &&
+		    (local_strncmp(name_val, MAX_KWORKNAME, name) != 0)) {
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+static __always_inline void do_update_time(void *map, struct work_key *key,
+					   __u64 time_start, __u64 time_end)
+{
+	struct report_data zero, *data;
+	__s64 delta = time_end - time_start;
+
+	if (delta < 0)
+		return;
+
+	data = bpf_map_lookup_elem(map, key);
+	if (!data) {
+		__builtin_memset(&zero, 0, sizeof(zero));
+		bpf_map_update_elem(map, key, &zero, BPF_NOEXIST);
+		data = bpf_map_lookup_elem(map, key);
+		if (!data)
+			return;
+	}
+
+	if ((delta > data->max_time) ||
+	    (data->max_time == 0)) {
+		data->max_time       = delta;
+		data->max_time_start = time_start;
+		data->max_time_end   = time_end;
+	}
+
+	data->total_time += delta;
+	data->nr++;
+}
+
+static __always_inline void do_update_timestart(void *map, struct work_key *key)
+{
+	__u64 ts = bpf_ktime_get_ns();
+
+	bpf_map_update_elem(map, key, &ts, BPF_ANY);
+}
+
+static __always_inline void do_update_timeend(void *report_map, void *time_map,
+					      struct work_key *key)
+{
+	__u64 *time = bpf_map_lookup_elem(time_map, key);
+
+	if (time) {
+		bpf_map_delete_elem(time_map, key);
+		do_update_time(report_map, key, *time, bpf_ktime_get_ns());
+	}
+}
+
+static __always_inline void do_update_name(void *map,
+					   struct work_key *key, char *name)
+{
+	if (!bpf_map_lookup_elem(map, key))
+		bpf_map_update_elem(map, key, name, BPF_ANY);
+}
+
+static __always_inline int update_timestart(void *map, struct work_key *key)
+{
+	if (!trace_event_match(key, NULL))
+		return 0;
+
+	do_update_timestart(map, key);
+	return 0;
+}
+
+static __always_inline int update_timestart_and_name(void *time_map,
+						     void *names_map,
+						     struct work_key *key,
+						     char *name)
+{
+	if (!trace_event_match(key, name))
+		return 0;
+
+	do_update_timestart(time_map, key);
+	do_update_name(names_map, key, name);
+
+	return 0;
+}
+
+static __always_inline int update_timeend(void *report_map,
+					  void *time_map, struct work_key *key)
+{
+	if (!trace_event_match(key, NULL))
+		return 0;
+
+	do_update_timeend(report_map, time_map, key);
+
+	return 0;
+}
+
+static __always_inline int update_timeend_and_name(void *report_map,
+						   void *time_map,
+						   void *names_map,
+						   struct work_key *key,
+						   char *name)
+{
+	if (!trace_event_match(key, name))
+		return 0;
+
+	do_update_timeend(report_map, time_map, key);
+	do_update_name(names_map, key, name);
+
+	return 0;
+}
+
+SEC("tracepoint/irq/irq_handler_entry")
+int report_irq_handler_entry(struct trace_event_raw_irq_handler_entry *ctx)
+{
+	char name[MAX_KWORKNAME];
+	struct work_key key = {
+		.type = KWORK_CLASS_IRQ,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)ctx->irq,
+	};
+	void *name_addr = (void *)ctx + (ctx->__data_loc_name & 0xffff);
+
+	bpf_probe_read_kernel_str(name, sizeof(name), name_addr);
+
+	return update_timestart_and_name(&perf_kwork_time,
+					 &perf_kwork_names, &key, name);
+}
+
+SEC("tracepoint/irq/irq_handler_exit")
+int report_irq_handler_exit(struct trace_event_raw_irq_handler_exit *ctx)
+{
+	struct work_key key = {
+		.type = KWORK_CLASS_IRQ,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)ctx->irq,
+	};
+
+	return update_timeend(&perf_kwork_report, &perf_kwork_time, &key);
+}
+
+static char softirq_name_list[NR_SOFTIRQS][MAX_KWORKNAME] = {
+	{ "HI"       },
+	{ "TIMER"    },
+	{ "NET_TX"   },
+	{ "NET_RX"   },
+	{ "BLOCK"    },
+	{ "IRQ_POLL" },
+	{ "TASKLET"  },
+	{ "SCHED"    },
+	{ "HRTIMER"  },
+	{ "RCU"      },
+};
+
+SEC("tracepoint/irq/softirq_entry")
+int report_softirq_entry(struct trace_event_raw_softirq *ctx)
+{
+	unsigned int vec = ctx->vec;
+	struct work_key key = {
+		.type = KWORK_CLASS_SOFTIRQ,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)vec,
+	};
+
+	if (vec < NR_SOFTIRQS) {
+		return update_timestart_and_name(&perf_kwork_time,
+						 &perf_kwork_names, &key,
+						 softirq_name_list[vec]);
+	}
+
+	return 0;
+}
+
+SEC("tracepoint/irq/softirq_exit")
+int report_softirq_exit(struct trace_event_raw_softirq *ctx)
+{
+	struct work_key key = {
+		.type = KWORK_CLASS_SOFTIRQ,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)ctx->vec,
+	};
+
+	return update_timeend(&perf_kwork_report, &perf_kwork_time, &key);
+}
+
+SEC("tracepoint/irq/softirq_raise")
+int latency_softirq_raise(struct trace_event_raw_softirq *ctx)
+{
+	unsigned int vec = ctx->vec;
+	struct work_key key = {
+		.type = KWORK_CLASS_SOFTIRQ,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)vec,
+	};
+
+	if (vec < NR_SOFTIRQS) {
+		return update_timestart_and_name(&perf_kwork_time,
+						 &perf_kwork_names, &key,
+						 softirq_name_list[vec]);
+	}
+
+	return 0;
+}
+
+SEC("tracepoint/irq/softirq_entry")
+int latency_softirq_entry(struct trace_event_raw_softirq *ctx)
+{
+	struct work_key key = {
+		.type = KWORK_CLASS_SOFTIRQ,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)ctx->vec,
+	};
+
+	return update_timeend(&perf_kwork_report, &perf_kwork_time, &key);
+}
+
+SEC("tracepoint/workqueue/workqueue_execute_start")
+int report_workqueue_execute_start(struct trace_event_raw_workqueue_execute_start *ctx)
+{
+	struct work_key key = {
+		.type = KWORK_CLASS_WORKQUEUE,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)ctx->work,
+	};
+
+	return update_timestart(&perf_kwork_time, &key);
+}
+
+SEC("tracepoint/workqueue/workqueue_execute_end")
+int report_workqueue_execute_end(struct trace_event_raw_workqueue_execute_end *ctx)
+{
+	char name[MAX_KWORKNAME];
+	struct work_key key = {
+		.type = KWORK_CLASS_WORKQUEUE,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)ctx->work,
+	};
+	unsigned long long func_addr = (unsigned long long)ctx->function;
+
+	__builtin_memset(name, 0, sizeof(name));
+	bpf_snprintf(name, sizeof(name), "%ps", &func_addr, sizeof(func_addr));
+
+	return update_timeend_and_name(&perf_kwork_report, &perf_kwork_time,
+				       &perf_kwork_names, &key, name);
+}
+
+SEC("tracepoint/workqueue/workqueue_activate_work")
+int latency_workqueue_activate_work(struct trace_event_raw_workqueue_activate_work *ctx)
+{
+	struct work_key key = {
+		.type = KWORK_CLASS_WORKQUEUE,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)ctx->work,
+	};
+
+	return update_timestart(&perf_kwork_time, &key);
+}
+
+SEC("tracepoint/workqueue/workqueue_execute_start")
+int latency_workqueue_execute_start(struct trace_event_raw_workqueue_execute_start *ctx)
+{
+	char name[MAX_KWORKNAME];
+	struct work_key key = {
+		.type = KWORK_CLASS_WORKQUEUE,
+		.cpu  = bpf_get_smp_processor_id(),
+		.id   = (__u64)ctx->work,
+	};
+	unsigned long long func_addr = (unsigned long long)ctx->function;
+
+	__builtin_memset(name, 0, sizeof(name));
+	bpf_snprintf(name, sizeof(name), "%ps", &func_addr, sizeof(func_addr));
+
+	return update_timeend_and_name(&perf_kwork_report, &perf_kwork_time,
+				       &perf_kwork_names, &key, name);
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c
new file mode 100644
index 000000000..1bb8628e7
--- /dev/null
+++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2022 Google
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+/* maximum stack trace depth */
+#define MAX_STACKS   8
+
+/* default buffer size */
+#define MAX_ENTRIES  10240
+
+struct contention_key {
+	__s32 stack_id;
+};
+
+struct contention_data {
+	__u64 total_time;
+	__u64 min_time;
+	__u64 max_time;
+	__u32 count;
+	__u32 flags;
+};
+
+struct tstamp_data {
+	__u64 timestamp;
+	__u64 lock;
+	__u32 flags;
+	__s32 stack_id;
+};
+
+/* callstack storage  */
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, MAX_STACKS * sizeof(__u64));
+	__uint(max_entries, MAX_ENTRIES);
+} stacks SEC(".maps");
+
+/* maintain timestamp at the beginning of contention */
+struct {
+	__uint(type, BPF_MAP_TYPE_TASK_STORAGE);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+	__type(key, int);
+	__type(value, struct tstamp_data);
+} tstamp SEC(".maps");
+
+/* actual lock contention statistics */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(struct contention_key));
+	__uint(value_size, sizeof(struct contention_data));
+	__uint(max_entries, MAX_ENTRIES);
+} lock_stat SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u8));
+	__uint(max_entries, 1);
+} cpu_filter SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u8));
+	__uint(max_entries, 1);
+} task_filter SEC(".maps");
+
+/* control flags */
+int enabled;
+int has_cpu;
+int has_task;
+int stack_skip;
+
+/* error stat */
+int lost;
+
+static inline int can_record(void)
+{
+	if (has_cpu) {
+		__u32 cpu = bpf_get_smp_processor_id();
+		__u8 *ok;
+
+		ok = bpf_map_lookup_elem(&cpu_filter, &cpu);
+		if (!ok)
+			return 0;
+	}
+
+	if (has_task) {
+		__u8 *ok;
+		__u32 pid = bpf_get_current_pid_tgid();
+
+		ok = bpf_map_lookup_elem(&task_filter, &pid);
+		if (!ok)
+			return 0;
+	}
+
+	return 1;
+}
+
+SEC("tp_btf/contention_begin")
+int contention_begin(u64 *ctx)
+{
+	struct task_struct *curr;
+	struct tstamp_data *pelem;
+
+	if (!enabled || !can_record())
+		return 0;
+
+	curr = bpf_get_current_task_btf();
+	pelem = bpf_task_storage_get(&tstamp, curr, NULL,
+				     BPF_LOCAL_STORAGE_GET_F_CREATE);
+	if (!pelem || pelem->lock)
+		return 0;
+
+	pelem->timestamp = bpf_ktime_get_ns();
+	pelem->lock = (__u64)ctx[0];
+	pelem->flags = (__u32)ctx[1];
+	pelem->stack_id = bpf_get_stackid(ctx, &stacks, BPF_F_FAST_STACK_CMP | stack_skip);
+
+	if (pelem->stack_id < 0)
+		lost++;
+	return 0;
+}
+
+SEC("tp_btf/contention_end")
+int contention_end(u64 *ctx)
+{
+	struct task_struct *curr;
+	struct tstamp_data *pelem;
+	struct contention_key key;
+	struct contention_data *data;
+	__u64 duration;
+
+	if (!enabled)
+		return 0;
+
+	curr = bpf_get_current_task_btf();
+	pelem = bpf_task_storage_get(&tstamp, curr, NULL, 0);
+	if (!pelem || pelem->lock != ctx[0])
+		return 0;
+
+	duration = bpf_ktime_get_ns() - pelem->timestamp;
+
+	key.stack_id = pelem->stack_id;
+	data = bpf_map_lookup_elem(&lock_stat, &key);
+	if (!data) {
+		struct contention_data first = {
+			.total_time = duration,
+			.max_time = duration,
+			.min_time = duration,
+			.count = 1,
+			.flags = pelem->flags,
+		};
+
+		bpf_map_update_elem(&lock_stat, &key, &first, BPF_NOEXIST);
+		pelem->lock = 0;
+		return 0;
+	}
+
+	__sync_fetch_and_add(&data->total_time, duration);
+	__sync_fetch_and_add(&data->count, 1);
+
+	/* FIXME: need atomic operations */
+	if (data->max_time < duration)
+		data->max_time = duration;
+	if (data->min_time > duration)
+		data->min_time = duration;
+
+	pelem->lock = 0;
+	return 0;
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
diff --git a/tools/perf/util/bpf_skel/off_cpu.bpf.c b/tools/perf/util/bpf_skel/off_cpu.bpf.c
new file mode 100644
index 000000000..38e3b287d
--- /dev/null
+++ b/tools/perf/util/bpf_skel/off_cpu.bpf.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2022 Google
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+/* task->flags for off-cpu analysis */
+#define PF_KTHREAD   0x00200000  /* I am a kernel thread */
+
+/* task->state for off-cpu analysis */
+#define TASK_INTERRUPTIBLE	0x0001
+#define TASK_UNINTERRUPTIBLE	0x0002
+
+/* create a new thread */
+#define CLONE_THREAD  0x10000
+
+#define MAX_STACKS   32
+#define MAX_ENTRIES  102400
+
+struct tstamp_data {
+	__u32 stack_id;
+	__u32 state;
+	__u64 timestamp;
+};
+
+struct offcpu_key {
+	__u32 pid;
+	__u32 tgid;
+	__u32 stack_id;
+	__u32 state;
+	__u64 cgroup_id;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, MAX_STACKS * sizeof(__u64));
+	__uint(max_entries, MAX_ENTRIES);
+} stacks SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_TASK_STORAGE);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+	__type(key, int);
+	__type(value, struct tstamp_data);
+} tstamp SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(struct offcpu_key));
+	__uint(value_size, sizeof(__u64));
+	__uint(max_entries, MAX_ENTRIES);
+} off_cpu SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u8));
+	__uint(max_entries, 1);
+} cpu_filter SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u8));
+	__uint(max_entries, 1);
+} task_filter SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u64));
+	__uint(value_size, sizeof(__u8));
+	__uint(max_entries, 1);
+} cgroup_filter SEC(".maps");
+
+/* new kernel task_struct definition */
+struct task_struct___new {
+	long __state;
+} __attribute__((preserve_access_index));
+
+/* old kernel task_struct definition */
+struct task_struct___old {
+	long state;
+} __attribute__((preserve_access_index));
+
+int enabled = 0;
+int has_cpu = 0;
+int has_task = 0;
+int has_cgroup = 0;
+int uses_tgid = 0;
+
+const volatile bool has_prev_state = false;
+const volatile bool needs_cgroup = false;
+const volatile bool uses_cgroup_v1 = false;
+
+int perf_subsys_id = -1;
+
+/*
+ * Old kernel used to call it task_struct->state and now it's '__state'.
+ * Use BPF CO-RE "ignored suffix rule" to deal with it like below:
+ *
+ * https://nakryiko.com/posts/bpf-core-reference-guide/#handling-incompatible-field-and-type-changes
+ */
+static inline int get_task_state(struct task_struct *t)
+{
+	/* recast pointer to capture new type for compiler */
+	struct task_struct___new *t_new = (void *)t;
+
+	if (bpf_core_field_exists(t_new->__state)) {
+		return BPF_CORE_READ(t_new, __state);
+	} else {
+		/* recast pointer to capture old type for compiler */
+		struct task_struct___old *t_old = (void *)t;
+
+		return BPF_CORE_READ(t_old, state);
+	}
+}
+
+static inline __u64 get_cgroup_id(struct task_struct *t)
+{
+	struct cgroup *cgrp;
+
+	if (!uses_cgroup_v1)
+		return BPF_CORE_READ(t, cgroups, dfl_cgrp, kn, id);
+
+	if (perf_subsys_id == -1) {
+#if __has_builtin(__builtin_preserve_enum_value)
+		perf_subsys_id = bpf_core_enum_value(enum cgroup_subsys_id,
+						     perf_event_cgrp_id);
+#else
+		perf_subsys_id = perf_event_cgrp_id;
+#endif
+	}
+
+	cgrp = BPF_CORE_READ(t, cgroups, subsys[perf_subsys_id], cgroup);
+	return BPF_CORE_READ(cgrp, kn, id);
+}
+
+static inline int can_record(struct task_struct *t, int state)
+{
+	/* kernel threads don't have user stack */
+	if (t->flags & PF_KTHREAD)
+		return 0;
+
+	if (state != TASK_INTERRUPTIBLE &&
+	    state != TASK_UNINTERRUPTIBLE)
+		return 0;
+
+	if (has_cpu) {
+		__u32 cpu = bpf_get_smp_processor_id();
+		__u8 *ok;
+
+		ok = bpf_map_lookup_elem(&cpu_filter, &cpu);
+		if (!ok)
+			return 0;
+	}
+
+	if (has_task) {
+		__u8 *ok;
+		__u32 pid;
+
+		if (uses_tgid)
+			pid = t->tgid;
+		else
+			pid = t->pid;
+
+		ok = bpf_map_lookup_elem(&task_filter, &pid);
+		if (!ok)
+			return 0;
+	}
+
+	if (has_cgroup) {
+		__u8 *ok;
+		__u64 cgrp_id = get_cgroup_id(t);
+
+		ok = bpf_map_lookup_elem(&cgroup_filter, &cgrp_id);
+		if (!ok)
+			return 0;
+	}
+
+	return 1;
+}
+
+static int off_cpu_stat(u64 *ctx, struct task_struct *prev,
+			struct task_struct *next, int state)
+{
+	__u64 ts;
+	__u32 stack_id;
+	struct tstamp_data *pelem;
+
+	ts = bpf_ktime_get_ns();
+
+	if (!can_record(prev, state))
+		goto next;
+
+	stack_id = bpf_get_stackid(ctx, &stacks,
+				   BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK);
+
+	pelem = bpf_task_storage_get(&tstamp, prev, NULL,
+				     BPF_LOCAL_STORAGE_GET_F_CREATE);
+	if (!pelem)
+		goto next;
+
+	pelem->timestamp = ts;
+	pelem->state = state;
+	pelem->stack_id = stack_id;
+
+next:
+	pelem = bpf_task_storage_get(&tstamp, next, NULL, 0);
+
+	if (pelem && pelem->timestamp) {
+		struct offcpu_key key = {
+			.pid = next->pid,
+			.tgid = next->tgid,
+			.stack_id = pelem->stack_id,
+			.state = pelem->state,
+			.cgroup_id = needs_cgroup ? get_cgroup_id(next) : 0,
+		};
+		__u64 delta = ts - pelem->timestamp;
+		__u64 *total;
+
+		total = bpf_map_lookup_elem(&off_cpu, &key);
+		if (total)
+			*total += delta;
+		else
+			bpf_map_update_elem(&off_cpu, &key, &delta, BPF_ANY);
+
+		/* prevent to reuse the timestamp later */
+		pelem->timestamp = 0;
+	}
+
+	return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int on_newtask(u64 *ctx)
+{
+	struct task_struct *task;
+	u64 clone_flags;
+	u32 pid;
+	u8 val = 1;
+
+	if (!uses_tgid)
+		return 0;
+
+	task = (struct task_struct *)bpf_get_current_task();
+
+	pid = BPF_CORE_READ(task, tgid);
+	if (!bpf_map_lookup_elem(&task_filter, &pid))
+		return 0;
+
+	task = (struct task_struct *)ctx[0];
+	clone_flags = ctx[1];
+
+	pid = task->tgid;
+	if (!(clone_flags & CLONE_THREAD))
+		bpf_map_update_elem(&task_filter, &pid, &val, BPF_NOEXIST);
+
+	return 0;
+}
+
+SEC("tp_btf/sched_switch")
+int on_switch(u64 *ctx)
+{
+	struct task_struct *prev, *next;
+	int prev_state;
+
+	if (!enabled)
+		return 0;
+
+	prev = (struct task_struct *)ctx[1];
+	next = (struct task_struct *)ctx[2];
+
+	if (has_prev_state)
+		prev_state = (int)ctx[3];
+	else
+		prev_state = get_task_state(prev);
+
+	return off_cpu_stat(ctx, prev, next, prev_state);
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";