linux-kernel - Re: [PATCH rcu 10/11] srcu: Add FORCE_NEED_SRCU_NMI

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: <CAMuHMdXsuKMLrg5qmS3oTAWfv3Ph34Hq5jeid974+RoTAR2Rkw@mail.gmail.com>
Date: Tue, 25 Mar 2025 16:36:23 +0100
From: Geert Uytterhoeven <geert@...ux-m68k.org>
To: paulmck@...nel.org
Cc: Boqun Feng <boqun.feng@...il.com>, rcu@...r.kernel.org, 
	Jonathan Corbet <corbet@....net>, Steven Rostedt <rostedt@...dmis.org>, 
	Masami Hiramatsu <mhiramat@...nel.org>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, 
	Frederic Weisbecker <frederic@...nel.org>, Neeraj Upadhyay <neeraj.upadhyay@...nel.org>, 
	Joel Fernandes <joel@...lfernandes.org>, Josh Triplett <josh@...htriplett.org>, 
	Uladzislau Rezki <urezki@...il.com>, Lai Jiangshan <jiangshanlai@...il.com>, 
	Zqiang <qiang.zhang1211@...il.com>, Davidlohr Bueso <dave@...olabs.net>, 
	Shuah Khan <shuah@...nel.org>, Andrew Morton <akpm@...ux-foundation.org>, 
	Thomas Huth <thuth@...hat.com>, "Borislav Petkov (AMD)" <bp@...en8.de>, Ard Biesheuvel <ardb@...nel.org>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Josh Poimboeuf <jpoimboe@...nel.org>, 
	Yury Norov <yury.norov@...il.com>, Valentin Schneider <vschneid@...hat.com>, linux-doc@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org, 
	linux-kselftest@...r.kernel.org
Subject: Re: [PATCH rcu 10/11] srcu: Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing

Hi Paul,

On Tue, 25 Mar 2025 at 16:08, Paul E. McKenney <paulmck@...nel.org> wrote:
> commit 2245ef8605a80726548253d885b4cadd97f69f3b
> Author: Paul E. McKenney <paulmck@...nel.org>
> Date:   Tue Mar 25 07:31:45 2025 -0700
>
>     srcu: Make FORCE_NEED_SRCU_NMI_SAFE depend on RCU_EXPERT
>
>     The FORCE_NEED_SRCU_NMI_SAFE is useful only for those wishing to test
>     the SRCU code paths that accommodate architectures that do not have
>     NMI-safe per-CPU operations, that is, those architectures that do not
>     select the ARCH_HAS_NMI_SAFE_THIS_CPU_OPS Kconfig option.  As such, this
>     is a specialized Kconfig option that is not intended for casual users.
>
>     This commit therefore hides it behind the RCU_EXPERT Kconfig option.
>     Given that this new FORCE_NEED_SRCU_NMI_SAFE Kconfig option has no effect
>     unless the ARCH_HAS_NMI_SAFE_THIS_CPU_OPS Kconfig option is also selected,
>     it also depends on this Kconfig option.
>
>     [ paulmck: Apply Geert Uytterhoeven feedback. ]
>
>     Reported-by: Geert Uytterhoeven <geert@...ux-m68k.org>
>     Closes: https://lore.kernel.org/all/CAMuHMdX6dy9_tmpLkpcnGzxyRbe6qSWYukcPp=H1GzZdyd3qBQ@mail.gmail.com/
>     Signed-off-by: Paul E. McKenney <paulmck@...nel.org>
>
> diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
> index b3f985d41717a..ceaf6594f634c 100644
> --- a/kernel/rcu/Kconfig
> +++ b/kernel/rcu/Kconfig
> @@ -68,6 +68,8 @@ config TREE_SRCU
>  config FORCE_NEED_SRCU_NMI_SAFE
>         bool "Force selection of NEED_SRCU_NMI_SAFE"
>         depends on !TINY_SRCU
> +       depends on RCU_EXPERT
> +       depends on ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
>         select NEED_SRCU_NMI_SAFE
>         default n
>         help

LGTM, so
Reviewed-by: Geert Uytterhoeven <geert@...ux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds