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author | Daniel T. Lee <danieltimlee@gmail.com> | 2020-08-23 17:53:33 +0900 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2020-08-24 20:59:35 -0700 |
commit | 3677d0a13171bb1dc8db0af84d48dea14a899962 (patch) | |
tree | 3de96b317e44d7e1eb175a4be093101f317e88ff /samples/bpf/trace_output_user.c | |
parent | 35a8b6dd339f04cbcb0b2d085334263542a12b70 (diff) | |
download | linux-3677d0a13171bb1dc8db0af84d48dea14a899962.tar.gz linux-3677d0a13171bb1dc8db0af84d48dea14a899962.tar.bz2 linux-3677d0a13171bb1dc8db0af84d48dea14a899962.zip |
samples: bpf: Refactor kprobe tracing programs with libbpf
For the problem of increasing fragmentation of the bpf loader programs,
instead of using bpf_loader.o, which is used in samples/bpf, this
commit refactors the existing kprobe tracing programs with libbbpf
bpf loader.
- For kprobe events pointing to system calls, the SYSCALL() macro in
trace_common.h was used.
- Adding a kprobe event and attaching a bpf program to it was done
through bpf_program_attach().
- Instead of using the existing BPF MAP definition, MAP definition
has been refactored with the new BTF-defined MAP format.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200823085334.9413-3-danieltimlee@gmail.com
Diffstat (limited to 'samples/bpf/trace_output_user.c')
-rw-r--r-- | samples/bpf/trace_output_user.c | 55 |
1 files changed, 37 insertions, 18 deletions
diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c index 60a17dd05345..364b98764d54 100644 --- a/samples/bpf/trace_output_user.c +++ b/samples/bpf/trace_output_user.c @@ -1,23 +1,10 @@ // SPDX-License-Identifier: GPL-2.0-only #include <stdio.h> -#include <unistd.h> -#include <stdlib.h> -#include <stdbool.h> -#include <string.h> #include <fcntl.h> #include <poll.h> -#include <linux/perf_event.h> -#include <linux/bpf.h> -#include <errno.h> -#include <assert.h> -#include <sys/syscall.h> -#include <sys/ioctl.h> -#include <sys/mman.h> #include <time.h> #include <signal.h> #include <bpf/libbpf.h> -#include "bpf_load.h" -#include "perf-sys.h" static __u64 time_get_ns(void) { @@ -57,20 +44,48 @@ static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size) int main(int argc, char **argv) { struct perf_buffer_opts pb_opts = {}; + struct bpf_link *link = NULL; + struct bpf_program *prog; struct perf_buffer *pb; + struct bpf_object *obj; + int map_fd, ret = 0; char filename[256]; FILE *f; - int ret; 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; + } - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; + /* 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, "my_map"); + if (map_fd < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); + if (libbpf_get_error(prog)) { + fprintf(stderr, "ERROR: finding a prog in obj file failed\n"); + goto cleanup; + } + + link = bpf_program__attach(prog); + if (libbpf_get_error(link)) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + link = NULL; + goto cleanup; } pb_opts.sample_cb = print_bpf_output; - pb = perf_buffer__new(map_fd[0], 8, &pb_opts); + pb = perf_buffer__new(map_fd, 8, &pb_opts); ret = libbpf_get_error(pb); if (ret) { printf("failed to setup perf_buffer: %d\n", ret); @@ -84,5 +99,9 @@ int main(int argc, char **argv) while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) { } kill(0, SIGINT); + +cleanup: + bpf_link__destroy(link); + bpf_object__close(obj); return ret; } |