Merge pull request iovisor#1702 from iovisor/yhs_dev

print out more useful attach_kprobe failure information
linux-kern · Apr 24, 2018 · 435dded · 435dded
2 parents a4782bd + 858a3d7
commit 435dded
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/src/cc/libbpf.c b/src/cc/libbpf.c
@@ -816,8 +816,10 @@ int bpf_attach_kprobe(int progfd, enum bpf_probe_attach_type attach_type,
  snprintf(buf, sizeof(buf), "%c:%ss/%s %s", attach_type==BPF_PROBE_ENTRY ? 'p' : 'r',
  event_type, event_alias, fn_name);
  if (write(kfd, buf, strlen(buf)) < 0) {
- if (errno == EINVAL)
- fprintf(stderr, "check dmesg output for possible cause\n");
+ if (errno == ENOENT)
+ fprintf(stderr, "cannot attach kprobe, probe entry may not exist\n");
+ else
+ fprintf(stderr, "cannot attach kprobe, %s\n", strerror(errno));
  close(kfd);
  goto error;
  }