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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /samples/bpf/syscall_tp_user.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/bpf/syscall_tp_user.c')
-rw-r--r-- | samples/bpf/syscall_tp_user.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/samples/bpf/syscall_tp_user.c b/samples/bpf/syscall_tp_user.c new file mode 100644 index 000000000..7a788bb83 --- /dev/null +++ b/samples/bpf/syscall_tp_user.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2017 Facebook + */ +#include <stdio.h> +#include <unistd.h> +#include <fcntl.h> +#include <stdlib.h> +#include <string.h> +#include <linux/perf_event.h> +#include <errno.h> +#include <bpf/libbpf.h> +#include <bpf/bpf.h> + +/* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*. + * This requires kernel CONFIG_FTRACE_SYSCALLS to be set. + */ + +static void usage(const char *cmd) +{ + printf("USAGE: %s [-i num_progs] [-h]\n", cmd); + printf(" -i num_progs # number of progs of the test\n"); + printf(" -h # help\n"); +} + +static void verify_map(int map_id) +{ + __u32 key = 0; + __u32 val; + + if (bpf_map_lookup_elem(map_id, &key, &val) != 0) { + fprintf(stderr, "map_lookup failed: %s\n", strerror(errno)); + return; + } + if (val == 0) { + fprintf(stderr, "failed: map #%d returns value 0\n", map_id); + return; + } + + printf("verify map:%d val: %d\n", map_id, val); + + val = 0; + if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) { + fprintf(stderr, "map_update failed: %s\n", strerror(errno)); + return; + } +} + +static int test(char *filename, int num_progs) +{ + int map0_fds[num_progs], map1_fds[num_progs], fd, i, j = 0; + struct bpf_link *links[num_progs * 4]; + struct bpf_object *objs[num_progs]; + struct bpf_program *prog; + + for (i = 0; i < num_progs; i++) { + objs[i] = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(objs[i])) { + fprintf(stderr, "opening BPF object file failed\n"); + objs[i] = NULL; + goto cleanup; + } + + /* load BPF program */ + if (bpf_object__load(objs[i])) { + fprintf(stderr, "loading BPF object file failed\n"); + goto cleanup; + } + + map0_fds[i] = bpf_object__find_map_fd_by_name(objs[i], + "enter_open_map"); + map1_fds[i] = bpf_object__find_map_fd_by_name(objs[i], + "exit_open_map"); + if (map0_fds[i] < 0 || map1_fds[i] < 0) { + fprintf(stderr, "finding a map in obj file failed\n"); + goto cleanup; + } + + bpf_object__for_each_program(prog, objs[i]) { + links[j] = bpf_program__attach(prog); + if (libbpf_get_error(links[j])) { + fprintf(stderr, "bpf_program__attach failed\n"); + links[j] = NULL; + goto cleanup; + } + j++; + } + printf("prog #%d: map ids %d %d\n", i, map0_fds[i], map1_fds[i]); + } + + /* current load_bpf_file has perf_event_open default pid = -1 + * and cpu = 0, which permits attached bpf execution on + * all cpus for all pid's. bpf program execution ignores + * cpu affinity. + */ + /* trigger some "open" operations */ + fd = open(filename, O_RDONLY); + if (fd < 0) { + fprintf(stderr, "open failed: %s\n", strerror(errno)); + return 1; + } + close(fd); + + /* verify the map */ + for (i = 0; i < num_progs; i++) { + verify_map(map0_fds[i]); + verify_map(map1_fds[i]); + } + +cleanup: + for (j--; j >= 0; j--) + bpf_link__destroy(links[j]); + + for (i--; i >= 0; i--) + bpf_object__close(objs[i]); + return 0; +} + +int main(int argc, char **argv) +{ + int opt, num_progs = 1; + char filename[256]; + + while ((opt = getopt(argc, argv, "i:h")) != -1) { + switch (opt) { + case 'i': + num_progs = atoi(optarg); + break; + case 'h': + default: + usage(argv[0]); + return 0; + } + } + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + + return test(filename, num_progs); +} |