Merge branch 'benchmark-runner'

Andrii Nakryiko says:

====================
Add generic benchmark runner framework which simplifies writing various
performance benchmarks in a consistent fashion.  This framework will be used
in follow up patches to test performance of perf buffer and ring buffer as
well.

Patch #1 extracts parse_num_list to be re-used between test_progs and bench.

Patch #2 adds generic runner implementation and atomic counter benchmarks to
validate benchmark runner's behavior.

Patch #3 implements test_overhead benchmark as part of bench runner. It also
add fmod_ret BPF program type to a set of benchmarks.

Patch #4 tests faster alternatives to set_task_comm() approach, tested in
test_overhead, in search for minimal-overhead way to trigger BPF program
execution from user-space on demand.

v2->v3:
  - added --prod-affinity and --cons-affinity (Yonghong);
  - removed ringbuf-related options leftovers (Yonghong);
  - added more benchmarking results for test_overhead performance discrepancies;
v1->v2:
  - moved benchmarks into benchs/ subdir (John);
  - added benchmark "suite" scripts (John);
  - few small clean ups, change defaults, etc.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/.gitignore

@@ -38,3 +38,4 @@ test_cpp
 /bpf_gcc
 /tools
 /runqslower
+/bench

tools/testing/selftests/bpf/Makefile

@@ -77,7 +77,7 @@ TEST_PROGS_EXTENDED := with_addr.sh \
 # Compile but not part of 'make run_tests'
 TEST_GEN_PROGS_EXTENDED = test_sock_addr test_skb_cgroup_id_user \
 	flow_dissector_load test_flow_dissector test_tcp_check_syncookie_user \
-	test_lirc_mode2_user xdping test_cpp runqslower
+	test_lirc_mode2_user xdping test_cpp runqslower bench
 
 TEST_CUSTOM_PROGS = urandom_read
 
@@ -355,7 +355,8 @@ endef
 TRUNNER_TESTS_DIR := prog_tests
 TRUNNER_BPF_PROGS_DIR := progs
 TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c	\
-			 network_helpers.c flow_dissector_load.h
+			 network_helpers.c testing_helpers.c		\
+			 flow_dissector_load.h
 TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read				\
 		       $(wildcard progs/btf_dump_test_case_*.c)
 TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE
@@ -406,6 +407,21 @@ $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
 	$(call msg,CXX,,$@)
 	$(CXX) $(CFLAGS) $^ $(LDLIBS) -o $@
 
+# Benchmark runner
+$(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h
+	$(call msg,CC,,$@)
+	$(CC) $(CFLAGS) -c $(filter %.c,$^) $(LDLIBS) -o $@
+$(OUTPUT)/bench_rename.o: $(OUTPUT)/test_overhead.skel.h
+$(OUTPUT)/bench_trigger.o: $(OUTPUT)/trigger_bench.skel.h
+$(OUTPUT)/bench.o: bench.h testing_helpers.h
+$(OUTPUT)/bench: LDLIBS += -lm
+$(OUTPUT)/bench: $(OUTPUT)/bench.o $(OUTPUT)/testing_helpers.o \
+		 $(OUTPUT)/bench_count.o \
+		 $(OUTPUT)/bench_rename.o \
+		 $(OUTPUT)/bench_trigger.o
+	$(call msg,BINARY,,$@)
+	$(CC) $(LDFLAGS) -o $@ $(filter %.a %.o,$^) $(LDLIBS)
+
 EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR)			\
 	prog_tests/tests.h map_tests/tests.h verifier/tests.h		\
 	feature								\

tools/testing/selftests/bpf/bench.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#pragma once
+#include <stdlib.h>
+#include <stdbool.h>
+#include <linux/err.h>
+#include <errno.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <math.h>
+#include <time.h>
+#include <sys/syscall.h>
+
+struct cpu_set {
+	bool *cpus;
+	int cpus_len;
+	int next_cpu;
+};
+
+struct env {
+	char *bench_name;
+	int duration_sec;
+	int warmup_sec;
+	bool verbose;
+	bool list;
+	bool affinity;
+	int consumer_cnt;
+	int producer_cnt;
+	struct cpu_set prod_cpus;
+	struct cpu_set cons_cpus;
+};
+
+struct bench_res {
+	long hits;
+	long drops;
+};
+
+struct bench {
+	const char *name;
+	void (*validate)();
+	void (*setup)();
+	void *(*producer_thread)(void *ctx);
+	void *(*consumer_thread)(void *ctx);
+	void (*measure)(struct bench_res* res);
+	void (*report_progress)(int iter, struct bench_res* res, long delta_ns);
+	void (*report_final)(struct bench_res res[], int res_cnt);
+};
+
+struct counter {
+	long value;
+} __attribute__((aligned(128)));
+
+extern struct env env;
+extern const struct bench *bench;
+
+void setup_libbpf();
+void hits_drops_report_progress(int iter, struct bench_res *res, long delta_ns);
+void hits_drops_report_final(struct bench_res res[], int res_cnt);
+
+static inline __u64 get_time_ns() {
+	struct timespec t;
+
+	clock_gettime(CLOCK_MONOTONIC, &t);
+
+	return (u64)t.tv_sec * 1000000000 + t.tv_nsec;
+}
+
+static inline void atomic_inc(long *value)
+{
+	(void)__atomic_add_fetch(value, 1, __ATOMIC_RELAXED);
+}
+
+static inline void atomic_add(long *value, long n)
+{
+	(void)__atomic_add_fetch(value, n, __ATOMIC_RELAXED);
+}
+
+static inline long atomic_swap(long *value, long n)
+{
+	return __atomic_exchange_n(value, n, __ATOMIC_RELAXED);
+}

tools/testing/selftests/bpf/benchs/bench_count.c

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include "bench.h"
+
+/* COUNT-GLOBAL benchmark */
+
+static struct count_global_ctx {
+	struct counter hits;
+} count_global_ctx;
+
+static void *count_global_producer(void *input)
+{
+	struct count_global_ctx *ctx = &count_global_ctx;
+
+	while (true) {
+		atomic_inc(&ctx->hits.value);
+	}
+	return NULL;
+}
+
+static void *count_global_consumer(void *input)
+{
+	return NULL;
+}
+
+static void count_global_measure(struct bench_res *res)
+{
+	struct count_global_ctx *ctx = &count_global_ctx;
+
+	res->hits = atomic_swap(&ctx->hits.value, 0);
+}
+
+/* COUNT-local benchmark */
+
+static struct count_local_ctx {
+	struct counter *hits;
+} count_local_ctx;
+
+static void count_local_setup()
+{
+	struct count_local_ctx *ctx = &count_local_ctx;
+
+	ctx->hits = calloc(env.consumer_cnt, sizeof(*ctx->hits));
+	if (!ctx->hits)
+		exit(1);
+}
+
+static void *count_local_producer(void *input)
+{
+	struct count_local_ctx *ctx = &count_local_ctx;
+	int idx = (long)input;
+
+	while (true) {
+		atomic_inc(&ctx->hits[idx].value);
+	}
+	return NULL;
+}
+
+static void *count_local_consumer(void *input)
+{
+	return NULL;
+}
+
+static void count_local_measure(struct bench_res *res)
+{
+	struct count_local_ctx *ctx = &count_local_ctx;
+	int i;
+
+	for (i = 0; i < env.producer_cnt; i++) {
+		res->hits += atomic_swap(&ctx->hits[i].value, 0);
+	}
+}
+
+const struct bench bench_count_global = {
+	.name = "count-global",
+	.producer_thread = count_global_producer,
+	.consumer_thread = count_global_consumer,
+	.measure = count_global_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_count_local = {
+	.name = "count-local",
+	.setup = count_local_setup,
+	.producer_thread = count_local_producer,
+	.consumer_thread = count_local_consumer,
+	.measure = count_local_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};

tools/testing/selftests/bpf/benchs/bench_rename.c

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include <fcntl.h>
+#include "bench.h"
+#include "test_overhead.skel.h"
+
+/* BPF triggering benchmarks */
+static struct ctx {
+	struct test_overhead *skel;
+	struct counter hits;
+	int fd;
+} ctx;
+
+static void validate()
+{
+	if (env.producer_cnt != 1) {
+		fprintf(stderr, "benchmark doesn't support multi-producer!\n");
+		exit(1);
+	}
+	if (env.consumer_cnt != 1) {
+		fprintf(stderr, "benchmark doesn't support multi-consumer!\n");
+		exit(1);
+	}
+}
+
+static void *producer(void *input)
+{
+	char buf[] = "test_overhead";
+	int err;
+
+	while (true) {
+		err = write(ctx.fd, buf, sizeof(buf));
+		if (err < 0) {
+			fprintf(stderr, "write failed\n");
+			exit(1);
+		}
+		atomic_inc(&ctx.hits.value);
+	}
+}
+
+static void measure(struct bench_res *res)
+{
+	res->hits = atomic_swap(&ctx.hits.value, 0);
+}
+
+static void setup_ctx()
+{
+	setup_libbpf();
+
+	ctx.skel = test_overhead__open_and_load();
+	if (!ctx.skel) {
+		fprintf(stderr, "failed to open skeleton\n");
+		exit(1);
+	}
+
+	ctx.fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
+	if (ctx.fd < 0) {
+		fprintf(stderr, "failed to open /proc/self/comm: %d\n", -errno);
+		exit(1);
+	}
+}
+
+static void attach_bpf(struct bpf_program *prog)
+{
+	struct bpf_link *link;
+
+	link = bpf_program__attach(prog);
+	if (IS_ERR(link)) {
+		fprintf(stderr, "failed to attach program!\n");
+		exit(1);
+	}
+}
+
+static void setup_base()
+{
+	setup_ctx();
+}
+
+static void setup_kprobe()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.prog1);
+}
+
+static void setup_kretprobe()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.prog2);
+}
+
+static void setup_rawtp()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.prog3);
+}
+
+static void setup_fentry()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.prog4);
+}
+
+static void setup_fexit()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.prog5);
+}
+
+static void setup_fmodret()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.prog6);
+}
+
+static void *consumer(void *input)
+{
+	return NULL;
+}
+
+const struct bench bench_rename_base = {
+	.name = "rename-base",
+	.validate = validate,
+	.setup = setup_base,
+	.producer_thread = producer,
+	.consumer_thread = consumer,
+	.measure = measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_kprobe = {
+	.name = "rename-kprobe",
+	.validate = validate,
+	.setup = setup_kprobe,
+	.producer_thread = producer,
+	.consumer_thread = consumer,
+	.measure = measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_kretprobe = {
+	.name = "rename-kretprobe",
+	.validate = validate,
+	.setup = setup_kretprobe,
+	.producer_thread = producer,
+	.consumer_thread = consumer,
+	.measure = measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_rawtp = {
+	.name = "rename-rawtp",
+	.validate = validate,
+	.setup = setup_rawtp,
+	.producer_thread = producer,
+	.consumer_thread = consumer,
+	.measure = measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_fentry = {
+	.name = "rename-fentry",
+	.validate = validate,
+	.setup = setup_fentry,
+	.producer_thread = producer,
+	.consumer_thread = consumer,
+	.measure = measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_fexit = {
+	.name = "rename-fexit",
+	.validate = validate,
+	.setup = setup_fexit,
+	.producer_thread = producer,
+	.consumer_thread = consumer,
+	.measure = measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_fmodret = {
+	.name = "rename-fmodret",
+	.validate = validate,
+	.setup = setup_fmodret,
+	.producer_thread = producer,
+	.consumer_thread = consumer,
+	.measure = measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};

tools/testing/selftests/bpf/benchs/bench_trigger.c

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include "bench.h"
+#include "trigger_bench.skel.h"
+
+/* BPF triggering benchmarks */
+static struct trigger_ctx {
+	struct trigger_bench *skel;
+} ctx;
+
+static struct counter base_hits;
+
+static void trigger_validate()
+{
+	if (env.consumer_cnt != 1) {
+		fprintf(stderr, "benchmark doesn't support multi-consumer!\n");
+		exit(1);
+	}
+}
+
+static void *trigger_base_producer(void *input)
+{
+	while (true) {
+		(void)syscall(__NR_getpgid);
+		atomic_inc(&base_hits.value);
+	}
+	return NULL;
+}
+
+static void trigger_base_measure(struct bench_res *res)
+{
+	res->hits = atomic_swap(&base_hits.value, 0);
+}
+
+static void *trigger_producer(void *input)
+{
+	while (true)
+		(void)syscall(__NR_getpgid);
+	return NULL;
+}
+
+static void trigger_measure(struct bench_res *res)
+{
+	res->hits = atomic_swap(&ctx.skel->bss->hits, 0);
+}
+
+static void setup_ctx()
+{
+	setup_libbpf();
+
+	ctx.skel = trigger_bench__open_and_load();
+	if (!ctx.skel) {
+		fprintf(stderr, "failed to open skeleton\n");
+		exit(1);
+	}
+}
+
+static void attach_bpf(struct bpf_program *prog)
+{
+	struct bpf_link *link;
+
+	link = bpf_program__attach(prog);
+	if (IS_ERR(link)) {
+		fprintf(stderr, "failed to attach program!\n");
+		exit(1);
+	}
+}
+
+static void trigger_tp_setup()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.bench_trigger_tp);
+}
+
+static void trigger_rawtp_setup()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.bench_trigger_raw_tp);
+}
+
+static void trigger_kprobe_setup()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.bench_trigger_kprobe);
+}
+
+static void trigger_fentry_setup()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.bench_trigger_fentry);
+}
+
+static void trigger_fmodret_setup()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.bench_trigger_fmodret);
+}
+
+static void *trigger_consumer(void *input)
+{
+	return NULL;
+}
+
+const struct bench bench_trig_base = {
+	.name = "trig-base",
+	.validate = trigger_validate,
+	.producer_thread = trigger_base_producer,
+	.consumer_thread = trigger_consumer,
+	.measure = trigger_base_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_tp = {
+	.name = "trig-tp",
+	.validate = trigger_validate,
+	.setup = trigger_tp_setup,
+	.producer_thread = trigger_producer,
+	.consumer_thread = trigger_consumer,
+	.measure = trigger_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_rawtp = {
+	.name = "trig-rawtp",
+	.validate = trigger_validate,
+	.setup = trigger_rawtp_setup,
+	.producer_thread = trigger_producer,
+	.consumer_thread = trigger_consumer,
+	.measure = trigger_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_kprobe = {
+	.name = "trig-kprobe",
+	.validate = trigger_validate,
+	.setup = trigger_kprobe_setup,
+	.producer_thread = trigger_producer,
+	.consumer_thread = trigger_consumer,
+	.measure = trigger_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_fentry = {
+	.name = "trig-fentry",
+	.validate = trigger_validate,
+	.setup = trigger_fentry_setup,
+	.producer_thread = trigger_producer,
+	.consumer_thread = trigger_consumer,
+	.measure = trigger_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_fmodret = {
+	.name = "trig-fmodret",
+	.validate = trigger_validate,
+	.setup = trigger_fmodret_setup,
+	.producer_thread = trigger_producer,
+	.consumer_thread = trigger_consumer,
+	.measure = trigger_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};

tools/testing/selftests/bpf/benchs/run_bench_rename.sh

+#!/bin/bash
+
+set -eufo pipefail
+
+for i in base kprobe kretprobe rawtp fentry fexit fmodret
+do
+	summary=$(sudo ./bench -w2 -d5 -a rename-$i | tail -n1 | cut -d'(' -f1 | cut -d' ' -f3-)
+	printf "%-10s: %s\n" $i "$summary"
+done

tools/testing/selftests/bpf/benchs/run_bench_trigger.sh

+#!/bin/bash
+
+set -eufo pipefail
+
+for i in base tp rawtp kprobe fentry fmodret
+do
+	summary=$(sudo ./bench -w2 -d5 -a trig-$i | tail -n1 | cut -d'(' -f1 | cut -d' ' -f3-)
+	printf "%-10s: %s\n" $i "$summary"
+done

tools/testing/selftests/bpf/prog_tests/test_overhead.c

@@ -61,9 +61,10 @@ void test_test_overhead(void)
 	const char *raw_tp_name = "raw_tp/task_rename";
 	const char *fentry_name = "fentry/__set_task_comm";
 	const char *fexit_name = "fexit/__set_task_comm";
+	const char *fmodret_name = "fmod_ret/__set_task_comm";
 	const char *kprobe_func = "__set_task_comm";
 	struct bpf_program *kprobe_prog, *kretprobe_prog, *raw_tp_prog;
-	struct bpf_program *fentry_prog, *fexit_prog;
+	struct bpf_program *fentry_prog, *fexit_prog, *fmodret_prog;
 	struct bpf_object *obj;
 	struct bpf_link *link;
 	int err, duration = 0;
@@ -96,6 +97,10 @@ void test_test_overhead(void)
 	if (CHECK(!fexit_prog, "find_probe",
 		  "prog '%s' not found\n", fexit_name))
 		goto cleanup;
+	fmodret_prog = bpf_object__find_program_by_title(obj, fmodret_name);
+	if (CHECK(!fmodret_prog, "find_probe",
+		  "prog '%s' not found\n", fmodret_name))
+		goto cleanup;
 
 	err = bpf_object__load(obj);
 	if (CHECK(err, "obj_load", "err %d\n", err))
@@ -142,6 +147,13 @@ void test_test_overhead(void)
 		goto cleanup;
 	test_run("fexit");
 	bpf_link__destroy(link);
+
+	/* attach fmod_ret */
+	link = bpf_program__attach_trace(fmodret_prog);
+	if (CHECK(IS_ERR(link), "attach fmod_ret", "err %ld\n", PTR_ERR(link)))
+		goto cleanup;
+	test_run("fmod_ret");
+	bpf_link__destroy(link);
 cleanup:
 	prctl(PR_SET_NAME, comm, 0L, 0L, 0L);
 	bpf_object__close(obj);

tools/testing/selftests/bpf/progs/test_overhead.c

@@ -39,4 +39,10 @@ int BPF_PROG(prog5, struct task_struct *tsk, const char *buf, bool exec)
 	return !tsk;
 }
 
+SEC("fmod_ret/__set_task_comm")
+int BPF_PROG(prog6, struct task_struct *tsk, const char *buf, bool exec)
+{
+	return !tsk;
+}
+
 char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/progs/trigger_bench.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+
+#include <linux/bpf.h>
+#include <asm/unistd.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+long hits = 0;
+
+SEC("tp/syscalls/sys_enter_getpgid")
+int bench_trigger_tp(void *ctx)
+{
+	__sync_add_and_fetch(&hits, 1);
+	return 0;
+}
+
+SEC("raw_tp/sys_enter")
+int BPF_PROG(bench_trigger_raw_tp, struct pt_regs *regs, long id)
+{
+	if (id == __NR_getpgid)
+		__sync_add_and_fetch(&hits, 1);
+	return 0;
+}
+
+SEC("kprobe/__x64_sys_getpgid")
+int bench_trigger_kprobe(void *ctx)
+{
+	__sync_add_and_fetch(&hits, 1);
+	return 0;
+}
+
+SEC("fentry/__x64_sys_getpgid")
+int bench_trigger_fentry(void *ctx)
+{
+	__sync_add_and_fetch(&hits, 1);
+	return 0;
+}
+
+SEC("fmod_ret/__x64_sys_getpgid")
+int bench_trigger_fmodret(void *ctx)
+{
+	__sync_add_and_fetch(&hits, 1);
+	return -22;
+}

tools/testing/selftests/bpf/test_progs.c

@@ -438,67 +438,6 @@ static int parse_str_list(const char *s, struct str_set *set)
 	return -ENOMEM;
 }
 
-int parse_num_list(const char *s, struct test_selector *sel)
-{
-	int i, set_len = 0, new_len, num, start = 0, end = -1;
-	bool *set = NULL, *tmp, parsing_end = false;
-	char *next;
-
-	while (s[0]) {
-		errno = 0;
-		num = strtol(s, &next, 10);
-		if (errno)
-			return -errno;
-
-		if (parsing_end)
-			end = num;
-		else
-			start = num;
-
-		if (!parsing_end && *next == '-') {
-			s = next + 1;
-			parsing_end = true;
-			continue;
-		} else if (*next == ',') {
-			parsing_end = false;
-			s = next + 1;
-			end = num;
-		} else if (*next == '\0') {
-			parsing_end = false;
-			s = next;
-			end = num;
-		} else {
-			return -EINVAL;
-		}
-
-		if (start > end)
-			return -EINVAL;
-
-		if (end + 1 > set_len) {
-			new_len = end + 1;
-			tmp = realloc(set, new_len);
-			if (!tmp) {
-				free(set);
-				return -ENOMEM;
-			}
-			for (i = set_len; i < start; i++)
-				tmp[i] = false;
-			set = tmp;
-			set_len = new_len;
-		}
-		for (i = start; i <= end; i++)
-			set[i] = true;
-	}
-
-	if (!set)
-		return -EINVAL;
-
-	sel->num_set = set;
-	sel->num_set_len = set_len;
-
-	return 0;
-}
-
 extern int extra_prog_load_log_flags;
 
 static error_t parse_arg(int key, char *arg, struct argp_state *state)
@@ -512,13 +451,15 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
 		if (subtest_str) {
 			*subtest_str = '\0';
 			if (parse_num_list(subtest_str + 1,
-					   &env->subtest_selector)) {
+					   &env->subtest_selector.num_set,
+					   &env->subtest_selector.num_set_len)) {
 				fprintf(stderr,
 					"Failed to parse subtest numbers.\n");
 				return -EINVAL;
 			}
 		}
-		if (parse_num_list(arg, &env->test_selector)) {
+		if (parse_num_list(arg, &env->test_selector.num_set,
+				   &env->test_selector.num_set_len)) {
 			fprintf(stderr, "Failed to parse test numbers.\n");
 			return -EINVAL;
 		}

tools/testing/selftests/bpf/test_progs.h

@@ -37,6 +37,7 @@ typedef __u16 __sum16;
 #include "bpf_util.h"
 #include <bpf/bpf_endian.h>
 #include "trace_helpers.h"
+#include "testing_helpers.h"
 #include "flow_dissector_load.h"
 
 enum verbosity {

tools/testing/selftests/bpf/testing_helpers.c

+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/* Copyright (C) 2020 Facebook, Inc. */
+#include <stdlib.h>
+#include <errno.h>
+#include "testing_helpers.h"
+
+int parse_num_list(const char *s, bool **num_set, int *num_set_len)
+{
+	int i, set_len = 0, new_len, num, start = 0, end = -1;
+	bool *set = NULL, *tmp, parsing_end = false;
+	char *next;
+
+	while (s[0]) {
+		errno = 0;
+		num = strtol(s, &next, 10);
+		if (errno)
+			return -errno;
+
+		if (parsing_end)
+			end = num;
+		else
+			start = num;
+
+		if (!parsing_end && *next == '-') {
+			s = next + 1;
+			parsing_end = true;
+			continue;
+		} else if (*next == ',') {
+			parsing_end = false;
+			s = next + 1;
+			end = num;
+		} else if (*next == '\0') {
+			parsing_end = false;
+			s = next;
+			end = num;
+		} else {
+			return -EINVAL;
+		}
+
+		if (start > end)
+			return -EINVAL;
+
+		if (end + 1 > set_len) {
+			new_len = end + 1;
+			tmp = realloc(set, new_len);
+			if (!tmp) {
+				free(set);
+				return -ENOMEM;
+			}
+			for (i = set_len; i < start; i++)
+				tmp[i] = false;
+			set = tmp;
+			set_len = new_len;
+		}
+		for (i = start; i <= end; i++)
+			set[i] = true;
+	}
+
+	if (!set)
+		return -EINVAL;
+
+	*num_set = set;
+	*num_set_len = set_len;
+
+	return 0;
+}

tools/testing/selftests/bpf/testing_helpers.h

+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (C) 2020 Facebook, Inc. */
+#include <stdbool.h>
+
+int parse_num_list(const char *s, bool **set, int *set_len);