From: Eduard Zingerman <eddyz87@gmail.com>
To: bpf@vger.kernel.org, ast@kernel.org
Cc: andrii@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev,
kernel-team@fb.com, yonghong.song@linux.dev, memxor@gmail.com,
awerner32@gmail.com, john.fastabend@gmail.com,
Eduard Zingerman <eddyz87@gmail.com>
Subject: [PATCH bpf-next 5/5] bpf: print full verifier states on infinite loop detection
Date: Sat, 21 Oct 2023 03:59:39 +0300 [thread overview]
Message-ID: <20231021005939.1041-6-eddyz87@gmail.com> (raw)
In-Reply-To: <20231021005939.1041-1-eddyz87@gmail.com>
Additional logging in is_state_visited(): if infinite loop is detected
print full verifier state for both current and equivalent states.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
---
kernel/bpf/verifier.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 117dafd9b1e7..29d7908d0ebe 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -16936,6 +16936,10 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
!iter_active_depths_differ(&sl->state, cur)) {
verbose_linfo(env, insn_idx, "; ");
verbose(env, "infinite loop detected at insn %d\n", insn_idx);
+ verbose(env, "cur state:");
+ print_verifier_state(env, cur->frame[cur->curframe], true);
+ verbose(env, "old state:");
+ print_verifier_state(env, sl->state.frame[cur->curframe], true);
return -EINVAL;
}
/* if the verifier is processing a loop, avoid adding new state
--
2.42.0
prev parent reply other threads:[~2023-10-21 1:00 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-21 0:59 [PATCH bpf-next 0/5] exact states comparison for iterator convergence checks Eduard Zingerman
2023-10-21 0:59 ` [PATCH bpf-next 1/5] bpf: " Eduard Zingerman
2023-10-21 21:41 ` Alexei Starovoitov
2023-10-21 0:59 ` [PATCH bpf-next 2/5] selftests/bpf: tests with delayed read/precision makrs in loop body Eduard Zingerman
2023-10-21 7:18 ` kernel test robot
2023-10-21 0:59 ` [PATCH bpf-next 3/5] bpf: correct loop detection for iterators convergence Eduard Zingerman
2023-10-21 0:59 ` [PATCH bpf-next 4/5] selftests/bpf: test if state loops are detected in a tricky case Eduard Zingerman
2023-10-21 7:30 ` kernel test robot
2023-10-21 0:59 ` Eduard Zingerman [this message]
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