netdev - Re: [PATCH v3 11/14] net: ncsi: Remove redundant rcu_read_lock/unlock() in spin

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <aMkw4zTLRJqpVGCm@home.paul.comp>
Date: Tue, 16 Sep 2025 12:41:55 +0300
From: Paul Fertser <fercerpav@...il.com>
To: pengdonglin <dolinux.peng@...il.com>
Cc: tj@...nel.org, tony.luck@...el.com, jani.nikula@...ux.intel.com,
        ap420073@...il.com, jv@...sburgh.net, freude@...ux.ibm.com,
        bcrl@...ck.org, trondmy@...nel.org, longman@...hat.com,
        kees@...nel.org, bigeasy@...utronix.de, hdanton@...a.com,
        paulmck@...nel.org, linux-kernel@...r.kernel.org,
        linux-rt-devel@...ts.linux.dev, linux-nfs@...r.kernel.org,
        linux-aio@...ck.org, linux-fsdevel@...r.kernel.org,
        linux-security-module@...r.kernel.org, netdev@...r.kernel.org,
        intel-gfx@...ts.freedesktop.org, linux-wireless@...r.kernel.org,
        linux-acpi@...r.kernel.org, linux-s390@...r.kernel.org,
        cgroups@...r.kernel.org, Samuel Mendoza-Jonas <sam@...dozajonas.com>,
        pengdonglin <pengdonglin@...omi.com>
Subject: Re: [PATCH v3 11/14] net: ncsi: Remove redundant
 rcu_read_lock/unlock() in spin_lock

Hello pengdonglin,

Thank you for the patch, looks reasonable and justified.

On Tue, Sep 16, 2025 at 12:47:32PM +0800, pengdonglin wrote:
> From: pengdonglin <pengdonglin@...omi.com>
> 
> Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side function definitions")
> there is no difference between rcu_read_lock(), rcu_read_lock_bh() and
> rcu_read_lock_sched() in terms of RCU read section and the relevant grace
> period. That means that spin_lock(), which implies rcu_read_lock_sched(),
> also implies rcu_read_lock().
> 
> There is no need no explicitly start a RCU read section if one has already
> been started implicitly by spin_lock().
> 
> Simplify the code and remove the inner rcu_read_lock() invocation.

Reviewed-by: Paul Fertser <fercerpav@...il.com>