change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/samples/bpf/xdp_monitor_user.c
..
..
@@ -26,12 +26,37 @@
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 #include <net/if.h>
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 #include <time.h>
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+#include <signal.h>
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 #include <bpf/bpf.h>
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-#include "bpf_load.h"
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+#include <bpf/libbpf.h>
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 #include "bpf_util.h"
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+enum map_type {
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+	REDIRECT_ERR_CNT,
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+	EXCEPTION_CNT,
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+	CPUMAP_ENQUEUE_CNT,
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+	CPUMAP_KTHREAD_CNT,
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+	DEVMAP_XMIT_CNT,
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+};
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+
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+static const char *const map_type_strings[] = {
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+	[REDIRECT_ERR_CNT] = "redirect_err_cnt",
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+	[EXCEPTION_CNT] = "exception_cnt",
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+	[CPUMAP_ENQUEUE_CNT] = "cpumap_enqueue_cnt",
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+	[CPUMAP_KTHREAD_CNT] = "cpumap_kthread_cnt",
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+	[DEVMAP_XMIT_CNT] = "devmap_xmit_cnt",
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+};
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+
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+#define NUM_MAP 5
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+#define NUM_TP 8
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+
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+static int tp_cnt;
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+static int map_cnt;
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 static int verbose = 1;
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 static bool debug = false;
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+struct bpf_map *map_data[NUM_MAP] = {};
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+struct bpf_link *tp_links[NUM_TP] = {};
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+struct bpf_object *obj;
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 static const struct option long_options[] = {
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 	{"help",	no_argument,		NULL, 'h' },
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..
@@ -40,6 +65,16 @@
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 	{"sec", 	required_argument,	NULL, 's' },
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 	{0, 0, NULL,  0 }
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 };
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+
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+static void int_exit(int sig)
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+{
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+	/* Detach tracepoints */
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+	while (tp_cnt)
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+		bpf_link__destroy(tp_links[--tp_cnt]);
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+
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+	bpf_object__close(obj);
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+	exit(0);
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+}
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 /* C standard specifies two constants, EXIT_SUCCESS(0) and EXIT_FAILURE(1) */
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 #define EXIT_FAIL_MEM	5
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@@ -483,23 +518,23 @@
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 	 * this can happen by someone running perf-record -e
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 	 */
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-	fd = map_data[0].fd; /* map0: redirect_err_cnt */
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+	fd = bpf_map__fd(map_data[REDIRECT_ERR_CNT]);
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 	for (i = 0; i < REDIR_RES_MAX; i++)
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 		map_collect_record_u64(fd, i, &rec->xdp_redirect[i]);
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-	fd = map_data[1].fd; /* map1: exception_cnt */
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+	fd = bpf_map__fd(map_data[EXCEPTION_CNT]);
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 	for (i = 0; i < XDP_ACTION_MAX; i++) {
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 		map_collect_record_u64(fd, i, &rec->xdp_exception[i]);
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 	}
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-	fd = map_data[2].fd; /* map2: cpumap_enqueue_cnt */
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+	fd = bpf_map__fd(map_data[CPUMAP_ENQUEUE_CNT]);
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 	for (i = 0; i < MAX_CPUS; i++)
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 		map_collect_record(fd, i, &rec->xdp_cpumap_enqueue[i]);
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-	fd = map_data[3].fd; /* map3: cpumap_kthread_cnt */
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+	fd = bpf_map__fd(map_data[CPUMAP_KTHREAD_CNT]);
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 	map_collect_record(fd, 0, &rec->xdp_cpumap_kthread);
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-	fd = map_data[4].fd; /* map4: devmap_xmit_cnt */
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+	fd = bpf_map__fd(map_data[DEVMAP_XMIT_CNT]);
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 	map_collect_record(fd, 0, &rec->xdp_devmap_xmit);
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 	return true;
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@@ -509,11 +544,8 @@
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 {
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 	unsigned int nr_cpus = bpf_num_possible_cpus();
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 	void *array;
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-	size_t size;
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-	size = record_size * nr_cpus;
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-	array = malloc(size);
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-	memset(array, 0, size);
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+	array = calloc(nr_cpus, record_size);
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 	if (!array) {
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 		fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
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 		exit(EXIT_FAIL_MEM);
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@@ -528,8 +560,7 @@
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 	int i;
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 	/* Alloc main stats_record structure */
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-	rec = malloc(sizeof(*rec));
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-	memset(rec, 0, sizeof(*rec));
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+	rec = calloc(1, sizeof(*rec));
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 	if (!rec) {
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 		fprintf(stderr, "Mem alloc error\n");
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 		exit(EXIT_FAIL_MEM);
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@@ -602,8 +633,8 @@
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 	/* TODO Need more advanced stats on error types */
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 	if (verbose) {
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-		printf(" - Stats map0: %s\n", map_data[0].name);
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-		printf(" - Stats map1: %s\n", map_data[1].name);
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+		printf(" - Stats map0: %s\n", bpf_map__name(map_data[0]));
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+		printf(" - Stats map1: %s\n", bpf_map__name(map_data[1]));
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 		printf("\n");
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 	}
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 	fflush(stdout);
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@@ -622,43 +653,50 @@
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653
 
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 static void print_bpf_prog_info(void)
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 {
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-	int i;
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+	struct bpf_program *prog;
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+	struct bpf_map *map;
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+	int i = 0;
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659
 
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 	/* Prog info */
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-	printf("Loaded BPF prog have %d bpf program(s)\n", prog_cnt);
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-	for (i = 0; i < prog_cnt; i++) {
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-		printf(" - prog_fd[%d] = fd(%d)\n", i, prog_fd[i]);
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+	printf("Loaded BPF prog have %d bpf program(s)\n", tp_cnt);
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+	bpf_object__for_each_program(prog, obj) {
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+		printf(" - prog_fd[%d] = fd(%d)\n", i, bpf_program__fd(prog));
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+		i++;
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 	}
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+	i = 0;
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 	/* Maps info */
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-	printf("Loaded BPF prog have %d map(s)\n", map_data_count);
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-	for (i = 0; i < map_data_count; i++) {
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-		char *name = map_data[i].name;
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-		int fd     = map_data[i].fd;
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+	printf("Loaded BPF prog have %d map(s)\n", map_cnt);
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+	bpf_object__for_each_map(map, obj) {
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+		const char *name = bpf_map__name(map);
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+		int fd		 = bpf_map__fd(map);
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 		printf(" - map_data[%d] = fd(%d) name:%s\n", i, fd, name);
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+		i++;
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 	}
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 	/* Event info */
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-	printf("Searching for (max:%d) event file descriptor(s)\n", prog_cnt);
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-	for (i = 0; i < prog_cnt; i++) {
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-		if (event_fd[i] != -1)
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-			printf(" - event_fd[%d] = fd(%d)\n", i, event_fd[i]);
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+	printf("Searching for (max:%d) event file descriptor(s)\n", tp_cnt);
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+	for (i = 0; i < tp_cnt; i++) {
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+		int fd = bpf_link__fd(tp_links[i]);
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+
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+		if (fd != -1)
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+			printf(" - event_fd[%d] = fd(%d)\n", i, fd);
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 	}
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 }
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 int main(int argc, char **argv)
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 {
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 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
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+	struct bpf_program *prog;
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 	int longindex = 0, opt;
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-	int ret = EXIT_SUCCESS;
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-	char bpf_obj_file[256];
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+	int ret = EXIT_FAILURE;
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+	enum map_type type;
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+	char filename[256];
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 	/* Default settings: */
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 	bool errors_only = true;
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 	int interval = 2;
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-
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-	snprintf(bpf_obj_file, sizeof(bpf_obj_file), "%s_kern.o", argv[0]);
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 	/* Parse commands line args */
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 	while ((opt = getopt_long(argc, argv, "hDSs:",
..
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@@ -676,40 +714,79 @@
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 		case 'h':
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 		default:
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 			usage(argv);
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-			return EXIT_FAILURE;
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+			return ret;
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 		}
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 	}
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+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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 	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
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 		perror("setrlimit(RLIMIT_MEMLOCK)");
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-		return EXIT_FAILURE;
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+		return ret;
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 	}
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-	if (load_bpf_file(bpf_obj_file)) {
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-		printf("ERROR - bpf_log_buf: %s", bpf_log_buf);
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-		return EXIT_FAILURE;
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+	/* Remove tracepoint program when program is interrupted or killed */
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+	signal(SIGINT, int_exit);
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+	signal(SIGTERM, int_exit);
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+
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+	obj = bpf_object__open_file(filename, NULL);
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+	if (libbpf_get_error(obj)) {
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+		printf("ERROR: opening BPF object file failed\n");
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+		obj = NULL;
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+		goto cleanup;
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 	}
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-	if (!prog_fd[0]) {
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-		printf("ERROR - load_bpf_file: %s\n", strerror(errno));
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-		return EXIT_FAILURE;
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+
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+	/* load BPF program */
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+	if (bpf_object__load(obj)) {
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+		printf("ERROR: loading BPF object file failed\n");
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+		goto cleanup;
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+	}
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+
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+	for (type = 0; type < NUM_MAP; type++) {
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+		map_data[type] =
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+			bpf_object__find_map_by_name(obj, map_type_strings[type]);
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+
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+		if (libbpf_get_error(map_data[type])) {
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+			printf("ERROR: finding a map in obj file failed\n");
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+			goto cleanup;
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+		}
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+		map_cnt++;
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+	}
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+
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+	bpf_object__for_each_program(prog, obj) {
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+		tp_links[tp_cnt] = bpf_program__attach(prog);
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+		if (libbpf_get_error(tp_links[tp_cnt])) {
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+			printf("ERROR: bpf_program__attach failed\n");
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+			tp_links[tp_cnt] = NULL;
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+			goto cleanup;
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+		}
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+		tp_cnt++;
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 	}
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 	if (debug) {
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 		print_bpf_prog_info();
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 	}
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-	/* Unload/stop tracepoint event by closing fd's */
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+	/* Unload/stop tracepoint event by closing bpf_link's */
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 	if (errors_only) {
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-		/* The prog_fd[i] and event_fd[i] depend on the
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-		 * order the functions was defined in _kern.c
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+		/* The bpf_link[i] depend on the order of
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+		 * the functions was defined in _kern.c
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 		 */
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-		close(event_fd[2]); /* tracepoint/xdp/xdp_redirect */
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-		close(prog_fd[2]);  /* func: trace_xdp_redirect */
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-		close(event_fd[3]); /* tracepoint/xdp/xdp_redirect_map */
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-		close(prog_fd[3]);  /* func: trace_xdp_redirect_map */
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+		bpf_link__destroy(tp_links[2]);	/* tracepoint/xdp/xdp_redirect */
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+		tp_links[2] = NULL;
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+
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+		bpf_link__destroy(tp_links[3]);	/* tracepoint/xdp/xdp_redirect_map */
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+		tp_links[3] = NULL;
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 	}
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 	stats_poll(interval, errors_only);
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782
 
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+	ret = EXIT_SUCCESS;
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+
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+cleanup:
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+	/* Detach tracepoints */
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+	while (tp_cnt)
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+		bpf_link__destroy(tp_links[--tp_cnt]);
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+
790
+	bpf_object__close(obj);
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 	return ret;
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 }