static int bpf_attach_tracing_event(int progfd, const char *event_path,
struct perf_reader *reader, int pid, int cpu, int group_fd) {
int efd = -1, rc = -1, pfd = -1;
ssize_t bytes = -1;
char buf[256];
struct perf_event_attr attr = {};
snprintf(buf, sizeof(buf), "%s/id", event_path);
efd = open(buf, O_RDONLY, 0);
if (efd < 0) {
fprintf(stderr, "open(%s): %s\n", buf, strerror(errno));
goto cleanup;
}
bytes = read(efd, buf, sizeof(buf));
if (bytes <= 0 || bytes >= sizeof(buf)) {
fprintf(stderr, "read(%s): %s\n", buf, strerror(errno));
goto cleanup;
}
buf[bytes] = '\0';
attr.config = strtol(buf, NULL, 0);
attr.type = PERF_TYPE_TRACEPOINT;
attr.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN;
attr.sample_period = 1;
attr.wakeup_events = 1;
pfd = syscall(__NR_perf_event_open, &attr, pid, cpu, group_fd, PERF_FLAG_FD_CLOEXEC);
if (pfd < 0) {
perror("perf_event_open");
goto cleanup;
}
if (perf_reader_mmap(reader, pfd, attr.sample_type) < 0)
goto cleanup;
if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, progfd) < 0) {
perror("ioctl(PERF_EVENT_IOC_SET_BPF)");
goto cleanup;
}
if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
perror("ioctl(PERF_EVENT_IOC_ENABLE)");
goto cleanup;
}
rc = pfd;
pfd = -1;
cleanup:
if (efd >= 0)
close(efd);
if (pfd >= 0)
close(pfd);
return rc;
}
void * bpf_open_perf_buffer(perf_reader_raw_cb raw_cb, void *cb_cookie, int pid, int cpu) {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,4,0)
int pfd;
struct perf_event_attr attr = {};
struct perf_reader *reader = NULL;
reader = perf_reader_new(NULL, raw_cb, cb_cookie);
if (!reader)
goto error;
attr.config = PERF_COUNT_SW_BPF_OUTPUT;
attr.type = PERF_TYPE_SOFTWARE;
attr.sample_type = PERF_SAMPLE_RAW;
attr.sample_period = 1;
attr.wakeup_events = 1;
pfd = syscall(__NR_perf_event_open, &attr, pid, cpu, -1, PERF_FLAG_FD_CLOEXEC);
if (pfd < 0) {
perror("perf_event_open");
goto error;
}
perf_reader_set_fd(reader, pfd);
if (perf_reader_mmap(reader, attr.type, attr.sample_type) < 0)
goto error;
if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
perror("ioctl(PERF_EVENT_IOC_ENABLE)");
goto error;
}
return reader;
error:
if (reader)
perf_reader_free(reader);
return NULL;
#else
fprintf(stderr, "PERF_COUNT_SW_BPF_OUTPUT feature unsupported\n");
return NULL;
#endif
}
void * bpf_open_perf_buffer(perf_reader_raw_cb raw_cb, void *cb_cookie, int pid, int cpu) {
int pfd;
struct perf_event_attr attr = {};
struct perf_reader *reader = NULL;
reader = perf_reader_new(NULL, raw_cb, cb_cookie);
if (!reader)
goto error;
attr.config = 10;//PERF_COUNT_SW_BPF_OUTPUT;
attr.type = PERF_TYPE_SOFTWARE;
attr.sample_type = PERF_SAMPLE_RAW;
attr.sample_period = 1;
attr.wakeup_events = 1;
pfd = syscall(__NR_perf_event_open, &attr, pid, cpu, -1, PERF_FLAG_FD_CLOEXEC);
if (pfd < 0) {
fprintf(stderr, "perf_event_open: %s\n", strerror(errno));
fprintf(stderr, " (check your kernel for PERF_COUNT_SW_BPF_OUTPUT support, 4.4 or newer)\n");
goto error;
}
perf_reader_set_fd(reader, pfd);
if (perf_reader_mmap(reader, attr.type, attr.sample_type) < 0)
goto error;
if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
perror("ioctl(PERF_EVENT_IOC_ENABLE)");
goto error;
}
return reader;
error:
if (reader)
perf_reader_free(reader);
return NULL;
}
