linux-kernel - Re: [patch 04/13] lockdep: Clenaup 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>] [day] [month] [year] [list]

Date:   Tue, 15 Sep 2020 17:11:05 +0100
From:   Will Deacon <will@...nel.org>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     LKML <linux-kernel@...r.kernel.org>, linux-arch@...r.kernel.org,
        Linus Torvalds <torvalds@...uxfoundation.org>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        Valentin Schneider <valentin.schneider@....com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>,
        Richard Henderson <rth@...ddle.net>,
        Ivan Kokshaysky <ink@...assic.park.msu.ru>,
        Matt Turner <mattst88@...il.com>, linux-alpha@...r.kernel.org,
        Jeff Dike <jdike@...toit.com>,
        Richard Weinberger <richard@....at>,
        Anton Ivanov <anton.ivanov@...bridgegreys.com>,
        linux-um@...ts.infradead.org, Brian Cain <bcain@...eaurora.org>,
        linux-hexagon@...r.kernel.org,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        linux-m68k@...ts.linux-m68k.org,
        Juri Lelli <juri.lelli@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
        Daniel Bristot de Oliveira <bristot@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
        Ingo Molnar <mingo@...hat.com>,
        Russell King <linux@...linux.org.uk>,
        linux-arm-kernel@...ts.infradead.org,
        Chris Zankel <chris@...kel.net>,
        Max Filippov <jcmvbkbc@...il.com>,
        linux-xtensa@...ux-xtensa.org,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        intel-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Josh Triplett <josh@...htriplett.org>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Lai Jiangshan <jiangshanlai@...il.com>,
        Shuah Khan <shuah@...nel.org>, rcu@...r.kernel.org,
        linux-kselftest@...r.kernel.org
Subject: Re: [patch 04/13] lockdep: Clenaup PREEMPT_COUNT leftovers

On Mon, Sep 14, 2020 at 10:42:13PM +0200, Thomas Gleixner wrote:
> CONFIG_PREEMPT_COUNT is now unconditionally enabled and will be
> removed. Cleanup the leftovers before doing so.
> 
> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
> Cc: Peter Zijlstra <peterz@...radead.org>
> Cc: Ingo Molnar <mingo@...nel.org>
> Cc: Will Deacon <will@...nel.org>
> ---
>  include/linux/lockdep.h |    6 ++----
>  lib/Kconfig.debug       |    1 -
>  2 files changed, 2 insertions(+), 5 deletions(-)
> 
> --- a/include/linux/lockdep.h
> +++ b/include/linux/lockdep.h
> @@ -585,16 +585,14 @@ do {									\
>  
>  #define lockdep_assert_preemption_enabled()				\
>  do {									\
> -	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
> -		     debug_locks			&&		\
> +	WARN_ON_ONCE(debug_locks			&&		\
>  		     (preempt_count() != 0		||		\
>  		      !raw_cpu_read(hardirqs_enabled)));		\
>  } while (0)
>  
>  #define lockdep_assert_preemption_disabled()				\
>  do {									\
> -	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
> -		     debug_locks			&&		\
> +	WARN_ON_ONCE(debug_locks			&&		\
>  		     (preempt_count() == 0		&&		\
>  		      raw_cpu_read(hardirqs_enabled)));			\
>  } while (0)
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1161,7 +1161,6 @@ config PROVE_LOCKING
>  	select DEBUG_RWSEMS
>  	select DEBUG_WW_MUTEX_SLOWPATH
>  	select DEBUG_LOCK_ALLOC
> -	select PREEMPT_COUNT
>  	select TRACE_IRQFLAGS
>  	default n
>  	help

Acked-by: Will Deacon <will@...nel.org>

Will