linux-kernel - Re: [PATCH v16 05/15] clocksource/drivers/arm_arch_timer: fix a bug in arch_timer_register about arch_timer_uses

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]

Date:   Fri, 18 Nov 2016 18:52:52 +0000
From:   Mark Rutland <mark.rutland@....com>
To:     fu.wei@...aro.org
Cc:     rjw@...ysocki.net, lenb@...nel.org, daniel.lezcano@...aro.org,
        tglx@...utronix.de, marc.zyngier@....com,
        lorenzo.pieralisi@....com, sudeep.holla@....com,
        hanjun.guo@...aro.org, linux-arm-kernel@...ts.infradead.org,
        linaro-acpi@...ts.linaro.org, linux-kernel@...r.kernel.org,
        linux-acpi@...r.kernel.org, rruigrok@...eaurora.org,
        harba@...eaurora.org, cov@...eaurora.org, timur@...eaurora.org,
        graeme.gregory@...aro.org, al.stone@...aro.org, jcm@...hat.com,
        wei@...hat.com, arnd@...db.de, catalin.marinas@....com,
        will.deacon@....com, Suravee.Suthikulpanit@....com,
        leo.duran@....com, wim@...ana.be, linux@...ck-us.net,
        linux-watchdog@...r.kernel.org, tn@...ihalf.com,
        christoffer.dall@...aro.org, julien.grall@....com
Subject: Re: [PATCH v16 05/15] clocksource/drivers/arm_arch_timer: fix a bug
 in arch_timer_register about arch_timer_uses_ppi

On Wed, Nov 16, 2016 at 09:48:58PM +0800, fu.wei@...aro.org wrote:
> From: Fu Wei <fu.wei@...aro.org>
> 
> The patch fix a potential bug about arch_timer_uses_ppi in
> arch_timer_register.
> On ARM64, we don't use ARCH_TIMER_PHYS_SECURE_PPI in Linux, so we will
> just igorne it in init code. 

That's not currently the case. I assume you mean we will in later
patches? If so, please make that clear in the commit message.

> If arch_timer_uses_ppi is ARCH_TIMER_PHYS_NONSECURE_PPI, the orignal
> code of arch_timer_uses_ppi may go wrong.

How? What specifically happens?

We don't currently assign ARCH_TIMER_PHYS_NONSECURE_PPI to
arch_timer_uses_ppi, so I assume a later patch changes this. This change
should be folded into said patch; it doesn't make sense in isolation.

Thanks,
Mark.

> Signed-off-by: Fu Wei <fu.wei@...aro.org>
> ---
>  drivers/clocksource/arm_arch_timer.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index dd1040d..6de164f 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -699,7 +699,7 @@ static int __init arch_timer_register(void)
>  	case ARCH_TIMER_PHYS_NONSECURE_PPI:
>  		err = request_percpu_irq(ppi, arch_timer_handler_phys,
>  					 "arch_timer", arch_timer_evt);
> -		if (!err && arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]) {
> +		if (!err && arch_timer_has_nonsecure_ppi()) {
>  			ppi = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI];
>  			err = request_percpu_irq(ppi, arch_timer_handler_phys,
>  						 "arch_timer", arch_timer_evt);
> -- 
> 2.7.4
>