From: Song Liu <songliubraving@fb.com>
To: KP Singh <kpsingh@chromium.org>
Cc: open list <linux-kernel@vger.kernel.org>,
bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>, Martin Lau <kafai@fb.com>,
Paul Turner <pjt@google.com>, Jann Horn <jannh@google.com>,
Hao Luo <haoluo@google.com>
Subject: Re: [PATCH bpf-next v4 1/9] bpf: Allow LSM programs to use bpf spin locks
Date: Thu, 5 Nov 2020 18:45:15 +0000 [thread overview]
Message-ID: <F1D417CF-8E33-4C65-9F91-FB391ABA5774@fb.com> (raw)
In-Reply-To: <20201105144755.214341-2-kpsingh@chromium.org>
> On Nov 5, 2020, at 6:47 AM, KP Singh <kpsingh@chromium.org> wrote:
>
> From: KP Singh <kpsingh@google.com>
>
> Usage of spin locks was not allowed for tracing programs due to
> insufficient preemption checks. The verifier does not currently prevent
> LSM programs from using spin locks, but the helpers are not exposed
> via bpf_lsm_func_proto.
>
> Based on the discussion in [1], non-sleepable LSM programs should be
> able to use bpf_spin_{lock, unlock}.
>
> Sleepable LSM programs can be preempted which means that allowng spin
> locks will need more work (disabling preemption and the verifier
> ensuring that no sleepable helpers are called when a spin lock is held).
>
> [1]: https://lore.kernel.org/bpf/20201103153132.2717326-1-kpsingh@chromium.org/T/#md601a053229287659071600d3483523f752cd2fb
>
> Signed-off-by: KP Singh <kpsingh@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
[...]
next prev parent reply other threads:[~2020-11-05 18:45 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-05 14:47 [PATCH bpf-next v4 0/9] Implement task_local_storage KP Singh
2020-11-05 14:47 ` [PATCH bpf-next v4 1/9] bpf: Allow LSM programs to use bpf spin locks KP Singh
2020-11-05 18:45 ` Song Liu [this message]
2020-11-05 20:39 ` Martin KaFai Lau
2020-11-05 14:47 ` [PATCH bpf-next v4 2/9] bpf: Implement task local storage KP Singh
2020-11-05 21:16 ` Martin KaFai Lau
2020-11-05 14:47 ` [PATCH bpf-next v4 3/9] libbpf: Add support for " KP Singh
2020-11-05 14:47 ` [PATCH bpf-next v4 4/9] bpftool: " KP Singh
2020-11-05 21:18 ` Martin KaFai Lau
2020-11-05 14:47 ` [PATCH bpf-next v4 5/9] bpf: Implement get_current_task_btf and RET_PTR_TO_BTF_ID KP Singh
2020-11-05 21:24 ` Martin KaFai Lau
2020-11-05 14:47 ` [PATCH bpf-next v4 6/9] bpf: Fix tests for local_storage KP Singh
2020-11-05 14:47 ` [PATCH bpf-next v4 7/9] bpf: Update selftests for local_storage to use vmlinux.h KP Singh
2020-11-05 14:47 ` [PATCH bpf-next v4 8/9] bpf: Add tests for task_local_storage KP Singh
2020-11-05 22:02 ` Martin KaFai Lau
2020-11-05 22:32 ` KP Singh
2020-11-05 14:47 ` [PATCH bpf-next v4 9/9] bpf: Exercise syscall operations for inode and sk storage KP Singh
2020-11-05 22:07 ` Martin KaFai Lau
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