linux-kernel - Re: [PATCH v3 5/7] sched/preempt: add PREEMPT

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: <YgTn7pnZ/hxmHBha@FVFF77S0Q05N>
Date:   Thu, 10 Feb 2022 10:27:39 +0000
From:   Mark Rutland <mark.rutland@....com>
To:     Frederic Weisbecker <frederic@...nel.org>
Cc:     linux-arm-kernel@...ts.infradead.org, ardb@...nel.org,
        bp@...en8.de, catalin.marinas@....com, dave.hansen@...ux.intel.com,
        james.morse@....com, joey.gouly@....com, juri.lelli@...hat.com,
        linux-kernel@...r.kernel.org, luto@...nel.org, mingo@...hat.com,
        peterz@...radead.org, tglx@...utronix.de,
        valentin.schneider@....com, will@...nel.org
Subject: Re: [PATCH v3 5/7] sched/preempt: add PREEMPT_DYNAMIC using static
 keys

On Wed, Feb 09, 2022 at 06:48:01PM +0100, Frederic Weisbecker wrote:
> On Wed, Feb 09, 2022 at 03:35:33PM +0000, Mark Rutland wrote:
> > +config HAVE_PREEMPT_DYNAMIC_KEY
> > +	bool
> > +	depends on JUMP_LABEL
> 
> This should probably be:
> 
>      depends on HAVE_ARCH_JUMP_LABEL && CC_HAS_ASM_GOTO
>      select JUMP_LABEL
> 
> Otherwise you may run into trouble if CONFIG_JUMP_LABEL is initially n.

I'll make that:

 config HAVE_PREEMPT_DYNAMIC_KEY
        bool
        depends on HAVE_ARCH_JUMP_LABEL && CC_HAS_ASM_GOTO
        ...

... and 

 config PREEMPT_DYNAMIC
        bool "Preemption behaviour defined on boot"
        depends on HAVE_PREEMPT_DYNAMIC && !PREEMPT_RT
        select JUMP_LABEL if HAVE_PREEMPT_DYNAMIC_KEY
        ...

So that we don't force JUMP_LABEL on even when people aren't using it.

Thanks,
Mark.