Merge branch 'convert-tests-to-libbpf'

Andrii Nakryiko says:

====================
There were few more tests and samples that were using custom perf buffer setup
code from trace_helpers.h. This patch set gets rid of all the usages of those
and removes helpers themselves. Libbpf provides nicer, but equally powerful
set of APIs to work with perf ring buffers, so let's have all the samples use

v1->v2:
- make logging message one long line instead of two (Song).
====================

Signed-off-by: Alexei Starovoitov <[email protected]>

Author: Alexei Starovoitov

samples/bpf/trace_output_user.c

@@ -18,9 +18,6 @@
 #include <libbpf.h>
 #include "bpf_load.h"
 #include "perf-sys.h"
-#include "trace_helpers.h"
-
-static int pmu_fd;
 
 static __u64 time_get_ns(void)
 {
@@ -31,12 +28,12 @@ static __u64 time_get_ns(void)
 }
 
 static __u64 start_time;
+static __u64 cnt;
 
 #define MAX_CNT 100000ll
 
-static int print_bpf_output(void *data, int size)
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
 {
-	static __u64 cnt;
 	struct {
 		__u64 pid;
 		__u64 cookie;
@@ -45,38 +42,22 @@ static int print_bpf_output(void *data, int size)
 	if (e->cookie != 0x12345678) {
 		printf("BUG pid %llx cookie %llx sized %d\n",
 		       e->pid, e->cookie, size);
-		return LIBBPF_PERF_EVENT_ERROR;
+		return;
 	}
 
 	cnt++;
 
 	if (cnt == MAX_CNT) {
 		printf("recv %lld events per sec\n",
 		       MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
-		return LIBBPF_PERF_EVENT_DONE;
+		return;
 	}
-
-	return LIBBPF_PERF_EVENT_CONT;
-}
-
-static void test_bpf_perf_event(void)
-{
-	struct perf_event_attr attr = {
-		.sample_type = PERF_SAMPLE_RAW,
-		.type = PERF_TYPE_SOFTWARE,
-		.config = PERF_COUNT_SW_BPF_OUTPUT,
-	};
-	int key = 0;
-
-	pmu_fd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
-
-	assert(pmu_fd >= 0);
-	assert(bpf_map_update_elem(map_fd[0], &key, &pmu_fd, BPF_ANY) == 0);
-	ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
 }
 
 int main(int argc, char **argv)
 {
+	struct perf_buffer_opts pb_opts = {};
+	struct perf_buffer *pb;
 	char filename[256];
 	FILE *f;
 	int ret;
@@ -88,16 +69,20 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	test_bpf_perf_event();
-
-	if (perf_event_mmap(pmu_fd) < 0)
+	pb_opts.sample_cb = print_bpf_output;
+	pb = perf_buffer__new(map_fd[0], 8, &pb_opts);
+	ret = libbpf_get_error(pb);
+	if (ret) {
+		printf("failed to setup perf_buffer: %d\n", ret);
 		return 1;
+	}
 
 	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
 	(void) f;
 
 	start_time = time_get_ns();
-	ret = perf_event_poller(pmu_fd, print_bpf_output);
+	while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
+	}
 	kill(0, SIGINT);
 	return ret;
 }

samples/bpf/xdp_sample_pkts_user.c

@@ -17,14 +17,13 @@
 #include <linux/if_link.h>
 
 #include "perf-sys.h"
-#include "trace_helpers.h"
 
 #define MAX_CPUS 128
-static int pmu_fds[MAX_CPUS], if_idx;
-static struct perf_event_mmap_page *headers[MAX_CPUS];
+static int if_idx;
 static char *if_name;
 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static __u32 prog_id;
+static struct perf_buffer *pb = NULL;
 
 static int do_attach(int idx, int fd, const char *name)
 {
@@ -73,7 +72,7 @@ static int do_detach(int idx, const char *name)
 
 #define SAMPLE_SIZE 64
 
-static int print_bpf_output(void *data, int size)
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
 {
 	struct {
 		__u16 cookie;
@@ -83,45 +82,20 @@ static int print_bpf_output(void *data, int size)
 	int i;
 
 	if (e->cookie != 0xdead) {
-		printf("BUG cookie %x sized %d\n",
-		       e->cookie, size);
-		return LIBBPF_PERF_EVENT_ERROR;
+		printf("BUG cookie %x sized %d\n", e->cookie, size);
+		return;
 	}
 
 	printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len);
 	for (i = 0; i < 14 && i < e->pkt_len; i++)
 		printf("%02x ", e->pkt_data[i]);
 	printf("\n");
-
-	return LIBBPF_PERF_EVENT_CONT;
-}
-
-static void test_bpf_perf_event(int map_fd, int num)
-{
-	struct perf_event_attr attr = {
-		.sample_type = PERF_SAMPLE_RAW,
-		.type = PERF_TYPE_SOFTWARE,
-		.config = PERF_COUNT_SW_BPF_OUTPUT,
-		.wakeup_events = 1, /* get an fd notification for every event */
-	};
-	int i;
-
-	for (i = 0; i < num; i++) {
-		int key = i;
-
-		pmu_fds[i] = sys_perf_event_open(&attr, -1/*pid*/, i/*cpu*/,
-						 -1/*group_fd*/, 0);
-
-		assert(pmu_fds[i] >= 0);
-		assert(bpf_map_update_elem(map_fd, &key,
-					   &pmu_fds[i], BPF_ANY) == 0);
-		ioctl(pmu_fds[i], PERF_EVENT_IOC_ENABLE, 0);
-	}
 }
 
 static void sig_handler(int signo)
 {
 	do_detach(if_idx, if_name);
+	perf_buffer__free(pb);
 	exit(0);
 }
 
@@ -140,13 +114,13 @@ int main(int argc, char **argv)
 	struct bpf_prog_load_attr prog_load_attr = {
 		.prog_type	= BPF_PROG_TYPE_XDP,
 	};
+	struct perf_buffer_opts pb_opts = {};
 	const char *optstr = "F";
 	int prog_fd, map_fd, opt;
 	struct bpf_object *obj;
 	struct bpf_map *map;
 	char filename[256];
-	int ret, err, i;
-	int numcpus;
+	int ret, err;
 
 	while ((opt = getopt(argc, argv, optstr)) != -1) {
 		switch (opt) {
@@ -169,10 +143,6 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	numcpus = get_nprocs();
-	if (numcpus > MAX_CPUS)
-		numcpus = MAX_CPUS;
-
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 	prog_load_attr.file = filename;
 
@@ -211,14 +181,17 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	test_bpf_perf_event(map_fd, numcpus);
+	pb_opts.sample_cb = print_bpf_output;
+	pb = perf_buffer__new(map_fd, 8, &pb_opts);
+	err = libbpf_get_error(pb);
+	if (err) {
+		perror("perf_buffer setup failed");
+		return 1;
+	}
 
-	for (i = 0; i < numcpus; i++)
-		if (perf_event_mmap_header(pmu_fds[i], &headers[i]) < 0)
-			return 1;
+	while ((ret = perf_buffer__poll(pb, 1000)) >= 0) {
+	}
 
-	ret = perf_event_poller_multi(pmu_fds, headers, numcpus,
-				      print_bpf_output);
 	kill(0, SIGINT);
 	return ret;
 }

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

@@ -1,8 +1,15 @@
 // SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <pthread.h>
+#include <sched.h>
+#include <sys/socket.h>
 #include <test_progs.h>
 
 #define MAX_CNT_RAWTP	10ull
 #define MAX_STACK_RAWTP	100
+
+static int duration = 0;
+
 struct get_stack_trace_t {
 	int pid;
 	int kern_stack_size;
@@ -13,7 +20,7 @@ struct get_stack_trace_t {
 	struct bpf_stack_build_id user_stack_buildid[MAX_STACK_RAWTP];
 };
 
-static int get_stack_print_output(void *data, int size)
+static void get_stack_print_output(void *ctx, int cpu, void *data, __u32 size)
 {
 	bool good_kern_stack = false, good_user_stack = false;
 	const char *nonjit_func = "___bpf_prog_run";
@@ -65,75 +72,76 @@ static int get_stack_print_output(void *data, int size)
 		if (e->user_stack_size > 0 && e->user_stack_buildid_size > 0)
 			good_user_stack = true;
 	}
-	if (!good_kern_stack || !good_user_stack)
-		return LIBBPF_PERF_EVENT_ERROR;
 
-	if (cnt == MAX_CNT_RAWTP)
-		return LIBBPF_PERF_EVENT_DONE;
-
-	return LIBBPF_PERF_EVENT_CONT;
+	if (!good_kern_stack)
+	    CHECK(!good_kern_stack, "kern_stack", "corrupted kernel stack\n");
+	if (!good_user_stack)
+	    CHECK(!good_user_stack, "user_stack", "corrupted user stack\n");
 }
 
 void test_get_stack_raw_tp(void)
 {
 	const char *file = "./test_get_stack_rawtp.o";
-	int i, efd, err, prog_fd, pmu_fd, perfmap_fd;
-	struct perf_event_attr attr = {};
+	const char *prog_name = "raw_tracepoint/sys_enter";
+	int i, err, prog_fd, exp_cnt = MAX_CNT_RAWTP;
+	struct perf_buffer_opts pb_opts = {};
+	struct perf_buffer *pb = NULL;
+	struct bpf_link *link = NULL;
 	struct timespec tv = {0, 10};
-	__u32 key = 0, duration = 0;
+	struct bpf_program *prog;
 	struct bpf_object *obj;
+	struct bpf_map *map;
+	cpu_set_t cpu_set;
 
 	err = bpf_prog_load(file, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd);
 	if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
 		return;
 
-	efd = bpf_raw_tracepoint_open("sys_enter", prog_fd);
-	if (CHECK(efd < 0, "raw_tp_open", "err %d errno %d\n", efd, errno))
+	prog = bpf_object__find_program_by_title(obj, prog_name);
+	if (CHECK(!prog, "find_probe", "prog '%s' not found\n", prog_name))
 		goto close_prog;
 
-	perfmap_fd = bpf_find_map(__func__, obj, "perfmap");
-	if (CHECK(perfmap_fd < 0, "bpf_find_map", "err %d errno %d\n",
-		  perfmap_fd, errno))
+	map = bpf_object__find_map_by_name(obj, "perfmap");
+	if (CHECK(!map, "bpf_find_map", "not found\n"))
 		goto close_prog;
 
 	err = load_kallsyms();
 	if (CHECK(err < 0, "load_kallsyms", "err %d errno %d\n", err, errno))
 		goto close_prog;
 
-	attr.sample_type = PERF_SAMPLE_RAW;
-	attr.type = PERF_TYPE_SOFTWARE;
-	attr.config = PERF_COUNT_SW_BPF_OUTPUT;
-	pmu_fd = syscall(__NR_perf_event_open, &attr, getpid()/*pid*/, -1/*cpu*/,
-			 -1/*group_fd*/, 0);
-	if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd,
-		  errno))
+	CPU_ZERO(&cpu_set);
+	CPU_SET(0, &cpu_set);
+	err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
+	if (CHECK(err, "set_affinity", "err %d, errno %d\n", err, errno))
 		goto close_prog;
 
-	err = bpf_map_update_elem(perfmap_fd, &key, &pmu_fd, BPF_ANY);
-	if (CHECK(err < 0, "bpf_map_update_elem", "err %d errno %d\n", err,
-		  errno))
+	link = bpf_program__attach_raw_tracepoint(prog, "sys_enter");
+	if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n", PTR_ERR(link)))
 		goto close_prog;
 
-	err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
-	if (CHECK(err < 0, "ioctl PERF_EVENT_IOC_ENABLE", "err %d errno %d\n",
-		  err, errno))
-		goto close_prog;
-
-	err = perf_event_mmap(pmu_fd);
-	if (CHECK(err < 0, "perf_event_mmap", "err %d errno %d\n", err, errno))
+	pb_opts.sample_cb = get_stack_print_output;
+	pb = perf_buffer__new(bpf_map__fd(map), 8, &pb_opts);
+	if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
 		goto close_prog;
 
 	/* trigger some syscall action */
 	for (i = 0; i < MAX_CNT_RAWTP; i++)
 		nanosleep(&tv, NULL);
 
-	err = perf_event_poller(pmu_fd, get_stack_print_output);
-	if (CHECK(err < 0, "perf_event_poller", "err %d errno %d\n", err, errno))
-		goto close_prog;
+	while (exp_cnt > 0) {
+		err = perf_buffer__poll(pb, 100);
+		if (err < 0 && CHECK(err < 0, "pb__poll", "err %d\n", err))
+			goto close_prog;
+		exp_cnt -= err;
+	}
 
 	goto close_prog_noerr;
 close_prog:
 	error_cnt++;
 close_prog_noerr:
+	if (!IS_ERR_OR_NULL(link))
+		bpf_link__destroy(link);
+	if (!IS_ERR_OR_NULL(pb))
+		perf_buffer__free(pb);
 	bpf_object__close(obj);
 }

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

@@ -55,7 +55,7 @@ struct {
 	__type(value, raw_stack_trace_t);
 } rawdata_map SEC(".maps");
 
-SEC("tracepoint/raw_syscalls/sys_enter")
+SEC("raw_tracepoint/sys_enter")
 int bpf_prog1(void *ctx)
 {
 	int max_len, max_buildid_len, usize, ksize, total_size;