netdev - [PATCH v2 bpf-next 07/10] bpf: increase verifier log limit

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Message-ID: <20190402042749.3670015-8-ast@kernel.org>
Date:   Mon, 1 Apr 2019 21:27:46 -0700
From:   Alexei Starovoitov <ast@...nel.org>
To:     <davem@...emloft.net>
CC:     <daniel@...earbox.net>, <jakub.kicinski@...ronome.com>,
        <jannh@...gle.com>, <netdev@...r.kernel.org>,
        <bpf@...r.kernel.org>, <kernel-team@...com>
Subject: [PATCH v2 bpf-next 07/10] bpf: increase verifier log limit

The existing 16Mbyte verifier log limit is not enough for log_level=2
even for small programs. Increase it to 1Gbyte.
Note it's not a kernel memory limit.
It's an amount of memory user space provides to store
the verifier log. The kernel populates it 1k at a time.

Signed-off-by: Alexei Starovoitov <ast@...nel.org>
Reviewed-by: Jakub Kicinski <jakub.kicinski@...ronome.com>
---
 kernel/bpf/verifier.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b631e89e7a51..bb27b675923c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -7974,7 +7974,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
 
 		ret = -EINVAL;
 		/* log attributes have to be sane */
-		if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 ||
+		if (log->len_total < 128 || log->len_total > UINT_MAX >> 2 ||
 		    !log->level || !log->ubuf || log->level & ~BPF_LOG_MASK)
 			goto err_unlock;
 	}
-- 
2.20.0