linux-kernel - Re: [PATCH bpf-next v2 1/2] bpf: Relax KF_ACQUIRE kfuncs strict type matching constraint

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Message-Id: 
 <172489082801.1473828.12809886195574675697.git-patchwork-notify@kernel.org>
Date: Thu, 29 Aug 2024 00:20:28 +0000
From: patchwork-bot+netdevbpf@...nel.org
To: Juntong Deng <juntong.deng@...look.com>
Cc: ast@...nel.org, daniel@...earbox.net, john.fastabend@...il.com,
 andrii@...nel.org, martin.lau@...ux.dev, eddyz87@...il.com, song@...nel.org,
 yonghong.song@...ux.dev, kpsingh@...nel.org, sdf@...ichev.me,
 haoluo@...gle.com, jolsa@...nel.org, memxor@...il.com, snorcht@...il.com,
 bpf@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH bpf-next v2 1/2] bpf: Relax KF_ACQUIRE kfuncs strict type
 matching constraint

Hello:

This series was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@...nel.org>:

On Wed, 28 Aug 2024 20:48:11 +0100 you wrote:
> Currently we cannot pass zero offset (implicit cast) or non-zero offset
> pointers to KF_ACQUIRE kfuncs. This is because KF_ACQUIRE kfuncs
> requires strict type matching, but zero offset or non-zero offset does
> not change the type of pointer, which causes the ebpf program to be
> rejected by the verifier.
> 
> This can cause some problems, one example is that bpf_skb_peek_tail
> kfunc [0] cannot be implemented by just passing in non-zero offset
> pointers. We cannot pass pointers like &sk->sk_write_queue (non-zero
> offset) or &sk->__sk_common (zero offset) to KF_ACQUIRE kfuncs.
> 
> [...]

Here is the summary with links:
  - [bpf-next,v2,1/2] bpf: Relax KF_ACQUIRE kfuncs strict type matching constraint
    https://git.kernel.org/bpf/bpf-next/c/f633919d132c
  - [bpf-next,v2,2/2] selftests/bpf: Add test for zero offset or non-zero offset pointers as KF_ACQUIRE kfuncs argument
    https://git.kernel.org/bpf/bpf-next/c/6db59c4935c9

You are awesome, thank you!
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