From: Daniel Borkmann <daniel@iogearbox.net>
To: KP Singh <kpsingh@kernel.org>, Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
Dmitrii Banshchikov <me@ubique.spb.ru>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
bpf <bpf@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] bpf: fix a warning message in mark_ptr_not_null_reg()
Date: Wed, 17 Feb 2021 01:37:38 +0100 [thread overview]
Message-ID: <04c60ed2-1a96-2835-9ae1-0ba84f482362@iogearbox.net> (raw)
In-Reply-To: <CACYkzJ55Ze+aA+qKA8bf=iqNY01H=MuDCKVmn44fLVW1670RxA@mail.gmail.com>
On 2/16/21 10:10 PM, KP Singh wrote:
> On Tue, Feb 16, 2021 at 8:37 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>>
>> The WARN_ON() argument is a condition, and it generates a stack trace
>> but it doesn't print the warning.
>>
>> Fixes: 4ddb74165ae5 ("bpf: Extract nullable reg type conversion into a helper function")
>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.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 056df6be3e30..bd4d1dfca73c 100644
>> --- a/kernel/bpf/verifier.c
>> +++ b/kernel/bpf/verifier.c
>> @@ -1120,7 +1120,7 @@ static void mark_ptr_not_null_reg(struct bpf_reg_state *reg)
>> reg->type = PTR_TO_RDWR_BUF;
>> break;
>> default:
>> - WARN_ON("unknown nullable register type");
>> + WARN(1, "unknown nullable register type");
>
> Should we use WARN_ONCE here? Also, I think the fix should be targeted
> for bpf-next as
> the patch that introduced this hasn't made it to bpf yet.
>
> [...]
Usually we have something like `verbose(env, "kernel subsystem misconfigured verifier\n")`,
but in this case we'd need to drag env all the way to here. :/ I agree with WARN_ONCE().
next prev parent reply other threads:[~2021-02-17 0:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-16 19:36 [PATCH] bpf: fix a warning message in mark_ptr_not_null_reg() Dan Carpenter
2021-02-16 21:10 ` KP Singh
2021-02-17 0:37 ` Daniel Borkmann [this message]
2021-02-17 7:45 ` [PATCH v2 bpf-next] " Dan Carpenter
2021-02-17 22:10 ` patchwork-bot+netdevbpf
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