change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/samples/bpf/sampleip_user.c
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..
@@ -1,26 +1,20 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 /*
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  * sampleip: sample instruction pointer and frequency count in a BPF map.
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  *
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  * Copyright 2016 Netflix, Inc.
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- *
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- * This program is free software; you can redistribute it and/or
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- * modify it under the terms of version 2 of the GNU General Public
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- * License as published by the Free Software Foundation.
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  */
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 #include <stdio.h>
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 #include <stdlib.h>
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-#include <stdio.h>
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 #include <unistd.h>
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 #include <errno.h>
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 #include <signal.h>
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 #include <string.h>
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-#include <assert.h>
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 #include <linux/perf_event.h>
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 #include <linux/ptrace.h>
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 #include <linux/bpf.h>
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-#include <sys/ioctl.h>
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-#include "libbpf.h"
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-#include "bpf_load.h"
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+#include <bpf/bpf.h>
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+#include <bpf/libbpf.h>
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 #include "perf-sys.h"
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 #include "trace_helpers.h"
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20
 
..
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@@ -29,6 +23,7 @@
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 #define MAX_IPS		8192
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 #define PAGE_OFFSET	0xffff880000000000
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+static int map_fd;
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 static int nr_cpus;
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 static void usage(void)
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@@ -38,9 +33,10 @@
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 	printf("       duration   # sampling duration (seconds), default 5\n");
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 }
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-static int sampling_start(int *pmu_fd, int freq)
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+static int sampling_start(int freq, struct bpf_program *prog,
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+			  struct bpf_link *links[])
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 {
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-	int i;
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+	int i, pmu_fd;
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 	struct perf_event_attr pe_sample_attr = {
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 		.type = PERF_TYPE_SOFTWARE,
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@@ -51,26 +47,30 @@
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 	};
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 	for (i = 0; i < nr_cpus; i++) {
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-		pmu_fd[i] = sys_perf_event_open(&pe_sample_attr, -1 /* pid */, i,
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+		pmu_fd = sys_perf_event_open(&pe_sample_attr, -1 /* pid */, i,
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 					    -1 /* group_fd */, 0 /* flags */);
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-		if (pmu_fd[i] < 0) {
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+		if (pmu_fd < 0) {
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 			fprintf(stderr, "ERROR: Initializing perf sampling\n");
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 			return 1;
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 		}
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-		assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF,
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-			     prog_fd[0]) == 0);
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-		assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0) == 0);
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+		links[i] = bpf_program__attach_perf_event(prog, pmu_fd);
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+		if (libbpf_get_error(links[i])) {
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+			fprintf(stderr, "ERROR: Attach perf event\n");
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+			links[i] = NULL;
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+			close(pmu_fd);
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+			return 1;
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+		}
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 	}
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 	return 0;
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 }
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-static void sampling_end(int *pmu_fd)
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+static void sampling_end(struct bpf_link *links[])
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 {
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 	int i;
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 	for (i = 0; i < nr_cpus; i++)
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-		close(pmu_fd[i]);
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+		bpf_link__destroy(links[i]);
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 }
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 struct ipcount {
..
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@@ -110,6 +110,11 @@
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 	for (i = 0; i < max; i++) {
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 		if (counts[i].ip > PAGE_OFFSET) {
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 			sym = ksym_search(counts[i].ip);
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+			if (!sym) {
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+				printf("ksym not found. Is kallsyms loaded?\n");
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+				continue;
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+			}
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+
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 			printf("0x%-17llx %-32s %u\n", counts[i].ip, sym->name,
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 			       counts[i].count);
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 		} else {
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@@ -127,14 +132,17 @@
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 static void int_exit(int sig)
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 {
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 	printf("\n");
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-	print_ip_map(map_fd[0]);
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+	print_ip_map(map_fd);
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 	exit(0);
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 }
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 int main(int argc, char **argv)
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 {
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+	int opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS, error = 1;
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+	struct bpf_object *obj = NULL;
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+	struct bpf_program *prog;
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+	struct bpf_link **links;
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 	char filename[256];
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-	int *pmu_fd, opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS;
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 	/* process arguments */
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 	while ((opt = getopt(argc, argv, "F:h")) != -1) {
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@@ -162,38 +170,58 @@
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 	}
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 	/* create perf FDs for each CPU */
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-	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
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-	pmu_fd = malloc(nr_cpus * sizeof(int));
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-	if (pmu_fd == NULL) {
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-		fprintf(stderr, "ERROR: malloc of pmu_fd\n");
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-		return 1;
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+	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
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+	links = calloc(nr_cpus, sizeof(struct bpf_link *));
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+	if (!links) {
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+		fprintf(stderr, "ERROR: malloc of links\n");
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+		goto cleanup;
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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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+	obj = bpf_object__open_file(filename, NULL);
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+	if (libbpf_get_error(obj)) {
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+		fprintf(stderr, "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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+
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+	prog = bpf_object__find_program_by_name(obj, "do_sample");
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+	if (!prog) {
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+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
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+		goto cleanup;
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 	}
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 	/* load BPF program */
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-	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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-	if (load_bpf_file(filename)) {
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-		fprintf(stderr, "ERROR: loading BPF program (errno %d):\n",
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-			errno);
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-		if (strcmp(bpf_log_buf, "") == 0)
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-			fprintf(stderr, "Try: ulimit -l unlimited\n");
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-		else
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-			fprintf(stderr, "%s", bpf_log_buf);
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-		return 1;
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+	if (bpf_object__load(obj)) {
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+		fprintf(stderr, "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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+	map_fd = bpf_object__find_map_fd_by_name(obj, "ip_map");
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+	if (map_fd < 0) {
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+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
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+		goto cleanup;
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+	}
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+
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 	signal(SIGINT, int_exit);
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 	signal(SIGTERM, int_exit);
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 	/* do sampling */
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 	printf("Sampling at %d Hertz for %d seconds. Ctrl-C also ends.\n",
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 	       freq, secs);
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-	if (sampling_start(pmu_fd, freq) != 0)
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-		return 1;
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+	if (sampling_start(freq, prog, links) != 0)
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+		goto cleanup;
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+
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 	sleep(secs);
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-	sampling_end(pmu_fd);
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-	free(pmu_fd);
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+	error = 0;
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+cleanup:
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+	sampling_end(links);
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 	/* output sample counts */
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-	print_ip_map(map_fd[0]);
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+	if (!error)
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+		print_ip_map(map_fd);
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-	return 0;
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+	free(links);
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+	bpf_object__close(obj);
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+	return error;
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 }