diff options
author | Daniel T. Lee <danieltimlee@gmail.com> | 2020-05-16 07:06:05 +0300 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-05-19 18:12:53 +0300 |
commit | 63841bc0833623ecd4f758ec055b543cf1bc56ba (patch) | |
tree | c1a534f8aaa1f3ce52712e752fdfd425d77a1eb7 /samples/bpf/tracex7_user.c | |
parent | 0efdcefb00d768442efef21560ea4c44d481fa5c (diff) | |
download | linux-63841bc0833623ecd4f758ec055b543cf1bc56ba.tar.xz |
samples, bpf: Refactor kprobe tracing user progs with libbpf
Currently, the kprobe BPF program attachment method for bpf_load is
quite old. The implementation of bpf_load "directly" controls and
manages(create, delete) the kprobe events of DEBUGFS. On the other hand,
using using the libbpf automatically manages the kprobe event.
(under bpf_link interface)
By calling bpf_program__attach(_kprobe) in libbpf, the corresponding
kprobe is created and the BPF program will be attached to this kprobe.
To remove this, by simply invoking bpf_link__destroy will clean up the
event.
This commit refactors kprobe tracing programs (tracex{1~7}_user.c) with
libbpf using bpf_link interface and bpf_program__attach.
tracex2_kern.c, which tracks system calls (sys_*), has been modified to
append prefix depending on architecture.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200516040608.1377876-3-danieltimlee@gmail.com
Diffstat (limited to 'samples/bpf/tracex7_user.c')
-rw-r--r-- | samples/bpf/tracex7_user.c | 39 |
1 files changed, 31 insertions, 8 deletions
diff --git a/samples/bpf/tracex7_user.c b/samples/bpf/tracex7_user.c index ea6dae78f0df..fdcd6580dd73 100644 --- a/samples/bpf/tracex7_user.c +++ b/samples/bpf/tracex7_user.c @@ -1,28 +1,51 @@ #define _GNU_SOURCE #include <stdio.h> -#include <linux/bpf.h> #include <unistd.h> -#include <bpf/bpf.h> -#include "bpf_load.h" +#include <bpf/libbpf.h> int main(int argc, char **argv) { - FILE *f; + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_object *obj; char filename[256]; char command[256]; - int ret; + int ret = 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; + } + + prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); + 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; + } - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; + link = bpf_program__attach(prog); + if (libbpf_get_error(link)) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + link = NULL; + goto cleanup; } snprintf(command, 256, "mount %s tmpmnt/", argv[1]); f = popen(command, "r"); ret = pclose(f); +cleanup: + bpf_link__destroy(link); + bpf_object__close(obj); return ret ? 0 : 1; } |