netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH][bpf-next] bpf: verifier: avoid fall-through warnings
@ 2019-07-11 16:22 Gustavo A. R. Silva
  2019-07-12 13:41 ` Daniel Borkmann
  0 siblings, 1 reply; 3+ messages in thread
From: Gustavo A. R. Silva @ 2019-07-11 16:22 UTC (permalink / raw)
  To: Alexei Starovoitov, Daniel Borkmann, Martin KaFai Lau, Song Liu,
	Yonghong Song, Andrii Nakryiko, Lawrence Brakmo
  Cc: netdev, bpf, linux-kernel, Gustavo A. R. Silva, Kees Cook

In preparation to enabling -Wimplicit-fallthrough, this patch silences
the following warning:

kernel/bpf/verifier.c: In function ‘check_return_code’:
kernel/bpf/verifier.c:6106:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (env->prog->expected_attach_type == BPF_CGROUP_UDP4_RECVMSG ||
      ^
kernel/bpf/verifier.c:6109:2: note: here
  case BPF_PROG_TYPE_CGROUP_SKB:
  ^~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

Notice that is much clearer to explicitly add breaks in each case
statement (that actually contains some code), rather than letting
the code to fall through.

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---

NOTE: -Wimplicit-fallthrough will be enabled globally in v5.3. So, I
      suggest you to take this patch for 5.3-rc1.

 kernel/bpf/verifier.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a2e763703c30..44c3b947400e 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6106,11 +6106,13 @@ static int check_return_code(struct bpf_verifier_env *env)
 		if (env->prog->expected_attach_type == BPF_CGROUP_UDP4_RECVMSG ||
 		    env->prog->expected_attach_type == BPF_CGROUP_UDP6_RECVMSG)
 			range = tnum_range(1, 1);
+		break;
 	case BPF_PROG_TYPE_CGROUP_SKB:
 		if (env->prog->expected_attach_type == BPF_CGROUP_INET_EGRESS) {
 			range = tnum_range(0, 3);
 			enforce_attach_type_range = tnum_range(2, 3);
 		}
+		break;
 	case BPF_PROG_TYPE_CGROUP_SOCK:
 	case BPF_PROG_TYPE_SOCK_OPS:
 	case BPF_PROG_TYPE_CGROUP_DEVICE:
-- 
2.21.0


^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-07-12 20:09 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-07-11 16:22 [PATCH][bpf-next] bpf: verifier: avoid fall-through warnings Gustavo A. R. Silva
2019-07-12 13:41 ` Daniel Borkmann
2019-07-12 19:44   ` Gustavo A. R. Silva

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).