[iproute2-next,0/2] Increase BPF verifier verbosity when in verbose mode

Message

Shung-Hsi Yu Oct. 18, 2023, 6:22 a.m. UTC

When debugging BPF verifier issue, it is useful get as much information
out of the verifier as possible to help diagnostic, but right now that
is not possible because load_bpf_object() does not set the
kernel_log_level in bpf_open_opts, which is addressed in patch 1.

Patch 2 further allows increasing the log level in verbose mode, so even
more information can be retrieved out of the verifier, and most
importlantly, show verifier log even on successful BPF program load.


Shung-Hsi Yu (2):
  libbpf: set kernel_log_level when available
  bpf: increase verifier verbosity when in verbose mode

 include/bpf_util.h |  4 ++--
 ip/ipvrf.c         |  3 ++-
 lib/bpf_legacy.c   | 10 ++++++----
 lib/bpf_libbpf.c   |  6 ++++++
 4 files changed, 16 insertions(+), 7 deletions(-)


base-commit: 575322b09c3c6bc1806f2faa31edcfb64df302bb

Comments

Shung-Hsi Yu Oct. 18, 2023, 1:59 p.m. UTC | #1

On Wed, Oct 18, 2023 at 02:22:32PM +0800, Shung-Hsi Yu wrote:
> When debugging BPF verifier issue, it is useful get as much information
> out of the verifier as possible to help diagnostic, but right now that
> is not possible because load_bpf_object() does not set the
> kernel_log_level in bpf_open_opts, which is addressed in patch 1.
> 
> Patch 2 further allows increasing the log level in verbose mode, so even
> more information can be retrieved out of the verifier, and most
> importlantly, show verifier log even on successful BPF program load.

Got some typos in patch 2, and bpf_open_opts should be bpf_object_open_opts.
Will send v2 to correct these mistakes.

> Shung-Hsi Yu (2):
>   libbpf: set kernel_log_level when available
>   bpf: increase verifier verbosity when in verbose mode
> 
>  include/bpf_util.h |  4 ++--
>  ip/ipvrf.c         |  3 ++-
>  lib/bpf_legacy.c   | 10 ++++++----
>  lib/bpf_libbpf.c   |  6 ++++++
>  4 files changed, 16 insertions(+), 7 deletions(-)
> 
> 
> base-commit: 575322b09c3c6bc1806f2faa31edcfb64df302bb
> -- 
> 2.42.0
>