Re: [patch net-next] selftests: bpf: don't try to read files without read permission

[Jakub Kicinski <jakub.kicinski@netronome.com>]

On Tue, 15 Oct 2019 12:00:56 +0200, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@mellanox.com>
> 
> Recently couple of files that are write only were added to netdevsim
> debugfs. Don't read these files and avoid error.
> 
> Reported-by: kernel test robot <rong.a.chen@intel.com>
> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
> ---
>  tools/testing/selftests/bpf/test_offload.py | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/bpf/test_offload.py b/tools/testing/selftests/bpf/test_offload.py
> index 15a666329a34..c44c650bde3a 100755
> --- a/tools/testing/selftests/bpf/test_offload.py
> +++ b/tools/testing/selftests/bpf/test_offload.py
> @@ -312,7 +312,7 @@ class DebugfsDir:
>              if f == "ports":
>                  continue
>              p = os.path.join(path, f)
> -            if os.path.isfile(p):
> +            if os.path.isfile(p) and os.access(p, os.R_OK):

Have you tested this? Looks like python always returns True here when
run as root, and this script requires root (and checks for it).

Also the fix is needed in net, not sure why you sent it to net-next.

>                  _, out = cmd('cat %s/%s' % (path, f))
>                  dfs[f] = out.strip()
>              elif os.path.isdir(p):