From: Tamir Duberstein <tamird@kernel.org>
To: Emil Tsalapatis <emil@etsalapatis.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
Jiri Olsa <jolsa@kernel.org>, Shuah Khan <shuah@kernel.org>,
Andrea Righi <arighi@nvidia.com>, Xu Kuohai <xukuohai@huawei.com>,
Andrea Righi <andrea.righi@canonical.com>,
bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org,
Andrew Werner <awerner32@gmail.com>,
Zvi Effron <zeffron@riotgames.com>,
Andrii Nakryiko <andriin@fb.com>
Subject: Re: [PATCH bpf 2/6] libbpf: ringbuf: Prevent NULL callback crash
Date: Thu, 18 Jun 2026 16:49:43 -0400 [thread overview]
Message-ID: <e384ef2f478093a70af11980d2d1cdeb@kernel.org> (raw)
In-Reply-To: <DJAWPR7RA9VX.2LHJ0V3EVGR7S@etsalapatis.com>
On Tue, Jun 16, 2026 at 08:44:13PM -0400, Emil Tsalapatis wrote:
[...]
> Can we just prevent a ring from being added with a NULL sample_cb?
> What's the use for permitting it?
I kept NULL callbacks valid because I plan to add a caller-owned
iterator that does not use callbacks. Rejecting NULL during construction
would prevent callers from creating iterator-only rings.
> Even if we don't, rechecking the callbacks every single time we
> consume the ringbuf seems overkill.
Your `unlikely()` suggestion on patch 6 applies here too, so I used it
in v2.
next prev parent reply other threads:[~2026-06-18 20:55 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-14 1:48 [PATCH bpf 0/6] libbpf: Fix ring buffer consumption Tamir Duberstein
2026-06-14 1:48 ` [PATCH bpf 1/6] libbpf: ringbuf: Honor zero consume bounds Tamir Duberstein
2026-06-17 0:35 ` Emil Tsalapatis
2026-06-14 1:48 ` [PATCH bpf 2/6] libbpf: ringbuf: Prevent NULL callback crash Tamir Duberstein
2026-06-17 0:44 ` Emil Tsalapatis
2026-06-18 20:49 ` Tamir Duberstein [this message]
2026-06-14 1:48 ` [PATCH bpf 3/6] libbpf: ringbuf: Handle position counter wrap Tamir Duberstein
2026-06-14 1:48 ` [PATCH bpf 4/6] libbpf: ringbuf: Use compiler atomics Tamir Duberstein
2026-06-17 1:30 ` Emil Tsalapatis
2026-06-14 1:48 ` [PATCH bpf 5/6] libbpf: ringbuf: Prevent missed wakeups Tamir Duberstein
2026-06-18 6:41 ` Emil Tsalapatis
2026-06-18 22:05 ` Tamir Duberstein
2026-06-14 1:48 ` [PATCH bpf 6/6] libbpf: ringbuf: Reject overwrite callback use Tamir Duberstein
2026-06-18 6:52 ` Emil Tsalapatis
2026-06-19 0:26 ` Tamir Duberstein
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