linux-kernel - Re: [PATCH v2 0/3] Fix arm_arch_timer clockmode when vDSO disabled

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: <87h7zg4adw.fsf@nanos.tec.linutronix.de>
Date:   Mon, 24 Feb 2020 10:12:11 +0100
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Marc Zyngier <maz@...nel.org>,
        Vincenzo Frascino <vincenzo.frascino@....com>
Cc:     linux-arch@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, catalin.marinas@....com,
        will.deacon@....com, linux@...linux.org.uk, luto@...nel.org,
        m.szyprowski@...sung.com, Mark.Rutland@....com
Subject: Re: [PATCH v2 0/3] Fix arm_arch_timer clockmode when vDSO disabled

Marc Zyngier <maz@...nel.org> writes:
> On Fri, 21 Feb 2020 18:18:46 +0000
> Vincenzo Frascino <vincenzo.frascino@....com> wrote:
>> 
>> This patch series addresses the issue defining a default arch clockmode
>> for arm and arm64 and using it to initialize the arm_arch_timer.
>
> arm only. arm64 is just fine.

Right. ARM64 unconditionaly enables VDSO

>
> This doesn't apply to -rc2, and is rather against next.

More precise it's against tip timers/core which has the VDSO changes
which caused this fallout.

>> Vincenzo Frascino (3):
>>   arm: clocksource: Add VDSO default clockmode
>>   arm64: clocksource: Add VDSO default clockmode
>>   clocksource: Fix arm_arch_timer clockmode when vDSO disabled
>
> Please squash the three patches into a single one. There is zero point
> in having 3 patches for something that small.

I really don't see why we need all this redefine foo. What's wrong with
the obvious?

--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -69,7 +69,12 @@ static enum arch_timer_ppi_nr arch_timer
 static bool arch_timer_c3stop;
 static bool arch_timer_mem_use_virtual;
 static bool arch_counter_suspend_stop;
+
+#ifdef CONFIG_GENERIC_GETTIMEOFDAY
 static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
+#else
+static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_NONE;
+#endif
 
 static cpumask_t evtstrm_available = CPU_MASK_NONE;
 static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);