linux-kernel - Re: [PATCH 08/21] drivers: base: Implement weak arch_unregister

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: <87sf4mxjuw.ffs@tglx>
Date:   Fri, 01 Dec 2023 12:06:31 +0100
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Russell King <rmk+kernel@...linux.org.uk>,
        linux-pm@...r.kernel.org, loongarch@...ts.linux.dev,
        linux-acpi@...r.kernel.org, linux-arch@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-riscv@...ts.infradead.org, kvmarm@...ts.linux.dev,
        x86@...nel.org, linux-csky@...r.kernel.org,
        linux-doc@...r.kernel.org, linux-ia64@...r.kernel.org,
        linux-parisc@...r.kernel.org
Cc:     Salil Mehta <salil.mehta@...wei.com>,
        Jean-Philippe Brucker <jean-philippe@...aro.org>,
        jianyong.wu@....com, justin.he@....com,
        James Morse <james.morse@....com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>
Subject: Re: [PATCH 08/21] drivers: base: Implement weak arch_unregister_cpu()

On Tue, Nov 21 2023 at 13:44, Russell King wrote:
> ---
> An open question remains from the RFC v2 posting: should we provide a
> __weak stub for !HOTPLUG_CPU as well, since in later patches ACPI may
> reference this if the compiler doesn't optimise as we expect?

You mean:

extern void foo(void);

    if (!IS_ENABLED(CONFIG_FOO))
    	foo();

The kernel uses this pattern for years and if someday a compiler starts
to fail to eliminate the call to 'foo()' for CONFIG_FOO=n then you
already get hundreds linkage fails today.

So adding one more in later patches won't matter much :)