netdev - Re: [PATCH bpf-next 02/14] bpf: net: Avoid sock_setsockopt() taking sk lock when called from bpf

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <YuFsHaTIu7dTzotG@google.com>
Date:   Wed, 27 Jul 2022 09:47:25 -0700
From:   sdf@...gle.com
To:     Martin KaFai Lau <kafai@...com>
Cc:     bpf@...r.kernel.org, netdev@...r.kernel.org,
        Alexei Starovoitov <ast@...nel.org>,
        Andrii Nakryiko <andrii@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        David Miller <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>, kernel-team@...com,
        Paolo Abeni <pabeni@...hat.com>
Subject: Re: [PATCH bpf-next 02/14] bpf: net: Avoid sock_setsockopt() taking
 sk lock when called from bpf

On 07/26, Martin KaFai Lau wrote:
> Most of the codes in bpf_setsockopt(SOL_SOCKET) are duplicated from
> the sock_setsockopt().  The number of supported options are
> increasing ever and so as the duplicated codes.

> One issue in reusing sock_setsockopt() is that the bpf prog
> has already acquired the sk lock.  sockptr_t is useful to handle this.
> sockptr_t already has a bit 'is_kernel' to handle the kernel-or-user
> memory copy.  This patch adds a 'is_bpf' bit to tell if sk locking
> has already been ensured by the bpf prog.

Why not explicitly call it is_locked/is_unlocked? I'm assuming, at some  
point,
we can have code paths in bpf where the socket has been already locked by
the stack?