From: Martin KaFai Lau <martin.lau@linux.dev>
To: David Vernet <void@manifault.com>,
ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org
Cc: kernel-team@fb.com, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org, yhs@fb.com, song@kernel.org,
john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
haoluo@google.com, jolsa@kernel.org, tj@kernel.org,
memxor@gmail.com
Subject: Re: [PATCH v2 1/2] bpf: Add kfuncs for storing struct task_struct * as a kptr
Date: Mon, 3 Oct 2022 12:20:57 -0700 [thread overview]
Message-ID: <b27deaa1-7ab2-a969-3475-4fa78db34f86@linux.dev> (raw)
In-Reply-To: <20221001144716.3403120-2-void@manifault.com>
On 10/1/22 7:47 AM, David Vernet wrote:
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index b069517a3da0..36cbe1b8f8b1 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -1700,20 +1700,93 @@ bpf_base_func_proto(enum bpf_func_id func_id)
> }
> }
>
> -BTF_SET8_START(tracing_btf_ids)
> +__diag_push();
> +__diag_ignore_all("-Wmissing-prototypes",
> + "Global functions as their definitions will be in vmlinux BTF");
> +
> +/**
> + * bpf_task_acquire - Acquire a reference to a task. A task acquired by this
> + * kfunc which is not stored in a map as a kptr, must be released by calling
> + * bpf_task_release().
> + * @p: The task on which a reference is being acquired.
> + */
> +__used noinline
> +struct task_struct *bpf_task_acquire(struct task_struct *p)
> +{
> + refcount_inc(&p->rcu_users);
This probably needs to be refcount_inc_not_zero() also for the cases like during
the task free tracepoint ?
next prev parent reply other threads:[~2022-10-03 19:21 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-01 14:47 [PATCH v2 0/2] Support storing struct task_struct objects as kptrs David Vernet
2022-10-01 14:47 ` [PATCH v2 1/2] bpf: Add kfuncs for storing struct task_struct * as a kptr David Vernet
2022-10-03 19:20 ` Martin KaFai Lau [this message]
2022-10-03 21:06 ` David Vernet
2022-10-01 14:47 ` [PATCH v2 2/2] bpf/selftests: Add selftests for new task kfuncs David Vernet
2022-10-03 0:32 ` Kumar Kartikeya Dwivedi
2022-10-03 15:35 ` David Vernet
2022-10-03 15:56 ` Kumar Kartikeya Dwivedi
2022-10-03 19:53 ` Martin KaFai Lau
2022-10-03 21:03 ` Kumar Kartikeya Dwivedi
2022-10-03 21:59 ` David Vernet
2022-10-03 22:22 ` Kumar Kartikeya Dwivedi
2022-10-04 15:10 ` David Vernet
2022-10-11 2:29 ` Kumar Kartikeya Dwivedi
2022-10-11 2:40 ` David Vernet
2022-10-04 5:10 ` Martin KaFai Lau
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