From: Yonghong Song <yonghong.song@linux.dev>
To: Andrii Nakryiko <andrii@kernel.org>,
bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
martin.lau@kernel.org
Cc: kernel-team@meta.com
Subject: Re: [PATCH bpf-next] libbpf: call dup2() syscall directly
Date: Sat, 20 Jan 2024 22:24:33 -0800 [thread overview]
Message-ID: <82363db5-7a78-4dc6-b0aa-4bc44152d77b@linux.dev> (raw)
In-Reply-To: <20240119210201.1295511-1-andrii@kernel.org>
On 1/19/24 1:02 PM, Andrii Nakryiko wrote:
> We've ran into issues with using dup2() API in production setting, where
> libbpf is linked into large production environment and ends up calling
> uninteded custom implementations of dup2(). These custom implementations
> don't provide atomic FD replacement guarantees of dup2() syscall,
> leading to subtle and hard to debug issues.
>
> To prevent this in the future and guarantee that no libc implementation
> will do their own custom non-atomic dup2() implementation, call dup2()
> syscall directly with syscall(SYS_dup2).
>
> Note that some architectures don't seem to provide dup2 and have dup3
> instead. Try to detect and pick best syscall.
>
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
next prev parent reply other threads:[~2024-01-21 6:24 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-19 21:02 [PATCH bpf-next] libbpf: call dup2() syscall directly Andrii Nakryiko
2024-01-19 21:18 ` Song Liu
2024-01-19 21:21 ` Andrii Nakryiko
2024-01-19 21:29 ` Andrii Nakryiko
2024-01-19 21:34 ` Song Liu
2024-01-19 21:42 ` Andrii Nakryiko
2024-01-21 6:24 ` Yonghong Song [this message]
2024-01-23 23:40 ` patchwork-bot+netdevbpf
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