// SPDX-License-Identifier: GPL-2.0-only/* Copyright (c) 2016 Facebook */#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <stdbool.h>#include <string.h>#include <linux/perf_event.h>#include <linux/bpf.h>#include <signal.h>#include <errno.h>#include <sys/resource.h>#include <bpf/bpf.h>#include <bpf/libbpf.h>#include "perf-sys.h"#include "trace_helpers.h" #define SAMPLE_FREQ 50 static int pid;/* counts, stackmap */static int map_fd[2];struct bpf_program *prog;static bool sys_read_seen, sys_write_seen; static void print_ksym(__u64 addr){	struct ksym *sym; 	if (!addr)		return;	sym = ksym_search(addr);	if (!sym) {		printf("ksym not found. Is kallsyms loaded?\n");		return;	} 	printf("%s;", sym->name);	if (!strstr(sym->name, "sys_read"))		sys_read_seen = true;	else if (!strstr(sym->name, "sys_write"))		sys_write_seen = true;} static void print_addr(__u64 addr){	if (!addr)		return;	printf("%llx;", addr);} #define TASK_COMM_LEN 16 struct key_t {	char comm[TASK_COMM_LEN];	__u32 kernstack;	__u32 userstack;}; static void print_stack(struct key_t *key, __u64 count){	__u64 ip[PERF_MAX_STACK_DEPTH] = {};	static bool warned;	int i; 	printf("%3lld %s;", count, key->comm);	if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {		printf("---;");	} else {		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)			print_ksym(ip[i]);	}	printf("-;");	if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {		printf("---;");	} else {		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)			print_addr(ip[i]);	}	if (count < 6)		printf("\r");	else		printf("\n"); 	if (key->kernstack == -EEXIST && !warned) {		printf("stackmap collisions seen. Consider increasing size\n");		warned = true;	} else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {		printf("err stackid %d %d\n", key->kernstack, key->userstack);	}} static void err_exit(int err){	kill(pid, SIGKILL);	exit(err);} static void print_stacks(void){	struct key_t key = {}, next_key;	__u64 value;	__u32 stackid = 0, next_id;	int error = 1, fd = map_fd[0], stack_map = map_fd[1]; 	sys_read_seen = sys_write_seen = false;	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {		bpf_map_lookup_elem(fd, &next_key, &value);		print_stack(&next_key, value);		bpf_map_delete_elem(fd, &next_key);		key = next_key;	}	printf("\n");	if (!sys_read_seen || !sys_write_seen) {		printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");		err_exit(error);	} 	/* clear stack map */	while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {		bpf_map_delete_elem(stack_map, &next_id);		stackid = next_id;	}} static inline int generate_load(void){	if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {		printf("failed to generate some load with dd: %s\n", strerror(errno));		return -1;	} 	return 0;} static void test_perf_event_all_cpu(struct perf_event_attr *attr){	int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);	struct bpf_link **links = calloc(nr_cpus, sizeof(struct bpf_link *));	int i, pmu_fd, error = 1; 	if (!links) {		printf("malloc of links failed\n");		goto err;	} 	/* system wide perf event, no need to inherit */	attr->inherit = 0; 	/* open perf_event on all cpus */	for (i = 0; i < nr_cpus; i++) {		pmu_fd = sys_perf_event_open(attr, -1, i, -1, 0);		if (pmu_fd < 0) {			printf("sys_perf_event_open failed\n");			goto all_cpu_err;		}		links[i] = bpf_program__attach_perf_event(prog, pmu_fd);		if (libbpf_get_error(links[i])) {			printf("bpf_program__attach_perf_event failed\n");			links[i] = NULL;			close(pmu_fd);			goto all_cpu_err;		}	} 	if (generate_load() < 0)		goto all_cpu_err; 	print_stacks();	error = 0;all_cpu_err:	for (i--; i >= 0; i--)		bpf_link__destroy(links[i]);err:	free(links);	if (error)		err_exit(error);} static void test_perf_event_task(struct perf_event_attr *attr){	struct bpf_link *link = NULL;	int pmu_fd, error = 1; 	/* per task perf event, enable inherit so the "dd ..." command can be traced properly.	 * Enabling inherit will cause bpf_perf_prog_read_time helper failure.	 */	attr->inherit = 1; 	/* open task bound event */	pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);	if (pmu_fd < 0) {		printf("sys_perf_event_open failed\n");		goto err;	}	link = bpf_program__attach_perf_event(prog, pmu_fd);	if (libbpf_get_error(link)) {		printf("bpf_program__attach_perf_event failed\n");		link = NULL;		close(pmu_fd);		goto err;	} 	if (generate_load() < 0)		goto err; 	print_stacks();	error = 0;err:	bpf_link__destroy(link);	if (error)		err_exit(error);} static void test_bpf_perf_event(void){	struct perf_event_attr attr_type_hw = {		.sample_freq = SAMPLE_FREQ,		.freq = 1,		.type = PERF_TYPE_HARDWARE,		.config = PERF_COUNT_HW_CPU_CYCLES,	};	struct perf_event_attr attr_type_sw = {		.sample_freq = SAMPLE_FREQ,		.freq = 1,		.type = PERF_TYPE_SOFTWARE,		.config = PERF_COUNT_SW_CPU_CLOCK,	};	struct perf_event_attr attr_hw_cache_l1d = {		.sample_freq = SAMPLE_FREQ,		.freq = 1,		.type = PERF_TYPE_HW_CACHE,		.config =			PERF_COUNT_HW_CACHE_L1D |			(PERF_COUNT_HW_CACHE_OP_READ << 8) |			(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),	};	struct perf_event_attr attr_hw_cache_branch_miss = {		.sample_freq = SAMPLE_FREQ,		.freq = 1,		.type = PERF_TYPE_HW_CACHE,		.config =			PERF_COUNT_HW_CACHE_BPU |			(PERF_COUNT_HW_CACHE_OP_READ << 8) |			(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),	};	struct perf_event_attr attr_type_raw = {		.sample_freq = SAMPLE_FREQ,		.freq = 1,		.type = PERF_TYPE_RAW,		/* Intel Instruction Retired */		.config = 0xc0,	};	struct perf_event_attr attr_type_raw_lock_load = {		.sample_freq = SAMPLE_FREQ,		.freq = 1,		.type = PERF_TYPE_RAW,		/* Intel MEM_UOPS_RETIRED.LOCK_LOADS */		.config = 0x21d0,		/* Request to record lock address from PEBS */		.sample_type = PERF_SAMPLE_ADDR,		/* Record address value requires precise event */		.precise_ip = 2,	}; 	printf("Test HW_CPU_CYCLES\n");	test_perf_event_all_cpu(&attr_type_hw);	test_perf_event_task(&attr_type_hw); 	printf("Test SW_CPU_CLOCK\n");	test_perf_event_all_cpu(&attr_type_sw);	test_perf_event_task(&attr_type_sw); 	printf("Test HW_CACHE_L1D\n");	test_perf_event_all_cpu(&attr_hw_cache_l1d);	test_perf_event_task(&attr_hw_cache_l1d); 	printf("Test HW_CACHE_BPU\n");	test_perf_event_all_cpu(&attr_hw_cache_branch_miss);	test_perf_event_task(&attr_hw_cache_branch_miss); 	printf("Test Instruction Retired\n");	test_perf_event_all_cpu(&attr_type_raw);	test_perf_event_task(&attr_type_raw); 	printf("Test Lock Load\n");	test_perf_event_all_cpu(&attr_type_raw_lock_load);	test_perf_event_task(&attr_type_raw_lock_load); 	printf("*** PASS ***\n");}  int main(int argc, char **argv){	struct bpf_object *obj = NULL;	char filename[256];	int error = 1; 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 	signal(SIGINT, err_exit);	signal(SIGTERM, err_exit); 	if (load_kallsyms()) {		printf("failed to process /proc/kallsyms\n");		goto cleanup;	} 	obj = bpf_object__open_file(filename, NULL);	if (libbpf_get_error(obj)) {		printf("opening BPF object file failed\n");		obj = NULL;		goto cleanup;	} 	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");	if (!prog) {		printf("finding a prog in obj file failed\n");		goto cleanup;	} 	/* load BPF program */	if (bpf_object__load(obj)) {		printf("loading BPF object file failed\n");		goto cleanup;	} 	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");	if (map_fd[0] < 0 || map_fd[1] < 0) {		printf("finding a counts/stackmap map in obj file failed\n");		goto cleanup;	} 	pid = fork();	if (pid == 0) {		read_trace_pipe();		return 0;	} else if (pid == -1) {		printf("couldn't spawn process\n");		goto cleanup;	} 	test_bpf_perf_event();	error = 0; cleanup:	bpf_object__close(obj);	err_exit(error);}