diff options
Diffstat (limited to 'samples/bpf/sampleip_user.c')
| -rw-r--r-- | samples/bpf/sampleip_user.c | 118 |
1 files changed, 77 insertions, 41 deletions
diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c index 216c7ecbbbe9..9283f47844fb 100644 --- a/samples/bpf/sampleip_user.c +++ b/samples/bpf/sampleip_user.c @@ -1,11 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * sampleip: sample instruction pointer and frequency count in a BPF map. * * Copyright 2016 Netflix, Inc. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of version 2 of the GNU General Public - * License as published by the Free Software Foundation. */ #include <stdio.h> #include <stdlib.h> @@ -13,22 +10,21 @@ #include <errno.h> #include <signal.h> #include <string.h> -#include <assert.h> #include <linux/perf_event.h> #include <linux/ptrace.h> #include <linux/bpf.h> -#include <sys/ioctl.h> -#include "libbpf.h" -#include "bpf_load.h" +#include <bpf/bpf.h> +#include <bpf/libbpf.h> #include "perf-sys.h" #include "trace_helpers.h" #define DEFAULT_FREQ 99 #define DEFAULT_SECS 5 #define MAX_IPS 8192 -#define PAGE_OFFSET 0xffff880000000000 +static int map_fd; static int nr_cpus; +static long _text_addr; static void usage(void) { @@ -37,9 +33,10 @@ static void usage(void) printf(" duration # sampling duration (seconds), default 5\n"); } -static int sampling_start(int *pmu_fd, int freq) +static int sampling_start(int freq, struct bpf_program *prog, + struct bpf_link *links[]) { - int i; + int i, pmu_fd; struct perf_event_attr pe_sample_attr = { .type = PERF_TYPE_SOFTWARE, @@ -50,26 +47,30 @@ static int sampling_start(int *pmu_fd, int freq) }; for (i = 0; i < nr_cpus; i++) { - pmu_fd[i] = sys_perf_event_open(&pe_sample_attr, -1 /* pid */, i, + pmu_fd = sys_perf_event_open(&pe_sample_attr, -1 /* pid */, i, -1 /* group_fd */, 0 /* flags */); - if (pmu_fd[i] < 0) { + if (pmu_fd < 0) { fprintf(stderr, "ERROR: Initializing perf sampling\n"); return 1; } - assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, - prog_fd[0]) == 0); - assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0) == 0); + links[i] = bpf_program__attach_perf_event(prog, pmu_fd); + if (libbpf_get_error(links[i])) { + fprintf(stderr, "ERROR: Attach perf event\n"); + links[i] = NULL; + close(pmu_fd); + return 1; + } } return 0; } -static void sampling_end(int *pmu_fd) +static void sampling_end(struct bpf_link *links[]) { int i; for (i = 0; i < nr_cpus; i++) - close(pmu_fd[i]); + bpf_link__destroy(links[i]); } struct ipcount { @@ -107,8 +108,13 @@ static void print_ip_map(int fd) /* sort and print */ qsort(counts, max, sizeof(struct ipcount), count_cmp); for (i = 0; i < max; i++) { - if (counts[i].ip > PAGE_OFFSET) { + if (counts[i].ip > _text_addr) { sym = ksym_search(counts[i].ip); + if (!sym) { + printf("ksym not found. Is kallsyms loaded?\n"); + continue; + } + printf("0x%-17llx %-32s %u\n", counts[i].ip, sym->name, counts[i].count); } else { @@ -126,14 +132,17 @@ static void print_ip_map(int fd) static void int_exit(int sig) { printf("\n"); - print_ip_map(map_fd[0]); + print_ip_map(map_fd); exit(0); } int main(int argc, char **argv) { + int opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS, error = 1; + struct bpf_object *obj = NULL; + struct bpf_program *prog; + struct bpf_link **links; char filename[256]; - int *pmu_fd, opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS; /* process arguments */ while ((opt = getopt(argc, argv, "F:h")) != -1) { @@ -160,39 +169,66 @@ int main(int argc, char **argv) return 2; } + /* used to determine whether the address is kernel space */ + _text_addr = ksym_get_addr("_text"); + if (!_text_addr) { + fprintf(stderr, "ERROR: no '_text' in /proc/kallsyms\n"); + return 3; + } + /* create perf FDs for each CPU */ - nr_cpus = sysconf(_SC_NPROCESSORS_CONF); - pmu_fd = malloc(nr_cpus * sizeof(int)); - if (pmu_fd == NULL) { - fprintf(stderr, "ERROR: malloc of pmu_fd\n"); - return 1; + nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); + links = calloc(nr_cpus, sizeof(struct bpf_link *)); + if (!links) { + fprintf(stderr, "ERROR: malloc of links\n"); + goto cleanup; } - /* load BPF program */ snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); - if (load_bpf_file(filename)) { - fprintf(stderr, "ERROR: loading BPF program (errno %d):\n", - errno); - if (strcmp(bpf_log_buf, "") == 0) - fprintf(stderr, "Try: ulimit -l unlimited\n"); - else - fprintf(stderr, "%s", bpf_log_buf); - return 1; + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + obj = NULL; + goto cleanup; } + + prog = bpf_object__find_program_by_name(obj, "do_sample"); + if (!prog) { + fprintf(stderr, "ERROR: finding a prog in obj file failed\n"); + goto cleanup; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + map_fd = bpf_object__find_map_fd_by_name(obj, "ip_map"); + if (map_fd < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + signal(SIGINT, int_exit); signal(SIGTERM, int_exit); /* do sampling */ printf("Sampling at %d Hertz for %d seconds. Ctrl-C also ends.\n", freq, secs); - if (sampling_start(pmu_fd, freq) != 0) - return 1; + if (sampling_start(freq, prog, links) != 0) + goto cleanup; + sleep(secs); - sampling_end(pmu_fd); - free(pmu_fd); + error = 0; +cleanup: + sampling_end(links); /* output sample counts */ - print_ip_map(map_fd[0]); + if (!error) + print_ip_map(map_fd); - return 0; + free(links); + bpf_object__close(obj); + return error; } |