diff options
Diffstat (limited to 'samples/bpf/tracex2_user.c')
| -rw-r--r-- | samples/bpf/tracex2_user.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/samples/bpf/tracex2_user.c b/samples/bpf/tracex2_user.c new file mode 100644 index 000000000..dd6205c6b --- /dev/null +++ b/samples/bpf/tracex2_user.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <signal.h> +#include <string.h> + +#include <bpf/bpf.h> +#include <bpf/libbpf.h> +#include "bpf_util.h" + +#define MAX_INDEX 64 +#define MAX_STARS 38 + +/* my_map, my_hist_map */ +static int map_fd[2]; + +static void stars(char *str, long val, long max, int width) +{ + int i; + + for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++) + str[i] = '*'; + if (val > max) + str[i - 1] = '+'; + str[i] = '\0'; +} + +struct task { + char comm[16]; + __u64 pid_tgid; + __u64 uid_gid; +}; + +struct hist_key { + struct task t; + __u32 index; +}; + +#define SIZE sizeof(struct task) + +static void print_hist_for_pid(int fd, void *task) +{ + unsigned int nr_cpus = bpf_num_possible_cpus(); + struct hist_key key = {}, next_key; + long values[nr_cpus]; + char starstr[MAX_STARS]; + long value; + long data[MAX_INDEX] = {}; + int max_ind = -1; + long max_value = 0; + int i, ind; + + while (bpf_map_get_next_key(fd, &key, &next_key) == 0) { + if (memcmp(&next_key, task, SIZE)) { + key = next_key; + continue; + } + bpf_map_lookup_elem(fd, &next_key, values); + value = 0; + for (i = 0; i < nr_cpus; i++) + value += values[i]; + ind = next_key.index; + data[ind] = value; + if (value && ind > max_ind) + max_ind = ind; + if (value > max_value) + max_value = value; + key = next_key; + } + + printf(" syscall write() stats\n"); + printf(" byte_size : count distribution\n"); + for (i = 1; i <= max_ind + 1; i++) { + stars(starstr, data[i - 1], max_value, MAX_STARS); + printf("%8ld -> %-8ld : %-8ld |%-*s|\n", + (1l << i) >> 1, (1l << i) - 1, data[i - 1], + MAX_STARS, starstr); + } +} + +static void print_hist(int fd) +{ + struct hist_key key = {}, next_key; + static struct task tasks[1024]; + int task_cnt = 0; + int i; + + while (bpf_map_get_next_key(fd, &key, &next_key) == 0) { + int found = 0; + + for (i = 0; i < task_cnt; i++) + if (memcmp(&tasks[i], &next_key, SIZE) == 0) + found = 1; + if (!found) + memcpy(&tasks[task_cnt++], &next_key, SIZE); + key = next_key; + } + + for (i = 0; i < task_cnt; i++) { + printf("\npid %d cmd %s uid %d\n", + (__u32) tasks[i].pid_tgid, + tasks[i].comm, + (__u32) tasks[i].uid_gid); + print_hist_for_pid(fd, &tasks[i]); + } + +} + +static void int_exit(int sig) +{ + print_hist(map_fd[1]); + exit(0); +} + +int main(int ac, char **argv) +{ + long key, next_key, value; + struct bpf_link *links[2]; + struct bpf_program *prog; + struct bpf_object *obj; + char filename[256]; + int i, j = 0; + FILE *f; + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + map_fd[0] = bpf_object__find_map_fd_by_name(obj, "my_map"); + map_fd[1] = bpf_object__find_map_fd_by_name(obj, "my_hist_map"); + if (map_fd[0] < 0 || map_fd[1] < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + signal(SIGINT, int_exit); + signal(SIGTERM, int_exit); + + /* start 'ping' in the background to have some kfree_skb events */ + f = popen("ping -4 -c5 localhost", "r"); + (void) f; + + /* start 'dd' in the background to have plenty of 'write' syscalls */ + f = popen("dd if=/dev/zero of=/dev/null count=5000000", "r"); + (void) f; + + bpf_object__for_each_program(prog, obj) { + links[j] = bpf_program__attach(prog); + if (libbpf_get_error(links[j])) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + links[j] = NULL; + goto cleanup; + } + j++; + } + + for (i = 0; i < 5; i++) { + key = 0; + while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0) { + bpf_map_lookup_elem(map_fd[0], &next_key, &value); + printf("location 0x%lx count %ld\n", next_key, value); + key = next_key; + } + if (key) + printf("\n"); + sleep(1); + } + print_hist(map_fd[1]); + +cleanup: + for (j--; j >= 0; j--) + bpf_link__destroy(links[j]); + + bpf_object__close(obj); + return 0; +} |