netdev - [PATCH bpf-next 8/9] bpf: add upper complexity limit to verifier log

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Message-Id: <20180120002437.3528-9-daniel@iogearbox.net>
Date:   Sat, 20 Jan 2018 01:24:36 +0100
From:   Daniel Borkmann <daniel@...earbox.net>
To:     ast@...nel.org
Cc:     netdev@...r.kernel.org, Daniel Borkmann <daniel@...earbox.net>
Subject: [PATCH bpf-next 8/9] bpf: add upper complexity limit to verifier log

Given the limit could potentially get further adjustments in the
future, add it to the log so it becomes obvious what the current
limit is w/o having to check the source first. This may also be
helpful for debugging complexity related issues on kernels that
backport from upstream.

Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
Acked-by: Alexei Starovoitov <ast@...nel.org>
---
 kernel/bpf/verifier.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 5eeb200..caae495 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4810,7 +4810,8 @@ static int do_check(struct bpf_verifier_env *env)
 		insn_idx++;
 	}
 
-	verbose(env, "processed %d insns, stack depth ", insn_processed);
+	verbose(env, "processed %d insns (limit %d), stack depth ",
+		insn_processed, BPF_COMPLEXITY_LIMIT_INSNS);
 	for (i = 0; i < env->subprog_cnt + 1; i++) {
 		u32 depth = env->subprog_stack_depth[i];
 
-- 
2.9.5