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3677d0a131
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
108 lines
2.3 KiB
C
108 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <stdio.h>
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#include <fcntl.h>
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#include <poll.h>
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#include <time.h>
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#include <signal.h>
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#include <bpf/libbpf.h>
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static __u64 time_get_ns(void)
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{
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struct timespec ts;
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clock_gettime(CLOCK_MONOTONIC, &ts);
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return ts.tv_sec * 1000000000ull + ts.tv_nsec;
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}
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static __u64 start_time;
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static __u64 cnt;
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#define MAX_CNT 100000ll
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static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
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{
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struct {
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__u64 pid;
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__u64 cookie;
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} *e = data;
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if (e->cookie != 0x12345678) {
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printf("BUG pid %llx cookie %llx sized %d\n",
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e->pid, e->cookie, size);
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return;
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}
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cnt++;
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if (cnt == MAX_CNT) {
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printf("recv %lld events per sec\n",
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MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
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return;
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}
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}
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int main(int argc, char **argv)
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{
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struct perf_buffer_opts pb_opts = {};
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struct bpf_link *link = NULL;
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struct bpf_program *prog;
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struct perf_buffer *pb;
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struct bpf_object *obj;
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int map_fd, ret = 0;
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char filename[256];
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FILE *f;
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snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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obj = bpf_object__open_file(filename, NULL);
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if (libbpf_get_error(obj)) {
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fprintf(stderr, "ERROR: opening BPF object file failed\n");
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return 0;
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}
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/* load BPF program */
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if (bpf_object__load(obj)) {
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fprintf(stderr, "ERROR: loading BPF object file failed\n");
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goto cleanup;
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}
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map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
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if (map_fd < 0) {
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fprintf(stderr, "ERROR: finding a map in obj file failed\n");
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goto cleanup;
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}
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prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
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if (libbpf_get_error(prog)) {
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fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
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goto cleanup;
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}
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link = bpf_program__attach(prog);
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if (libbpf_get_error(link)) {
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fprintf(stderr, "ERROR: bpf_program__attach failed\n");
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link = NULL;
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goto cleanup;
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}
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pb_opts.sample_cb = print_bpf_output;
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pb = perf_buffer__new(map_fd, 8, &pb_opts);
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ret = libbpf_get_error(pb);
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if (ret) {
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printf("failed to setup perf_buffer: %d\n", ret);
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return 1;
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}
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f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
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(void) f;
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start_time = time_get_ns();
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while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
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}
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kill(0, SIGINT);
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cleanup:
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bpf_link__destroy(link);
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bpf_object__close(obj);
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return ret;
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}
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