linux-kernel - Re: [patch -rt 2/2] KVM: lapic: mark LAPIC timer handler as irqsafe

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:	Tue, 25 Nov 2014 18:38:04 +0100
From:	Paolo Bonzini <pbonzini@...hat.com>
To:	Marcelo Tosatti <mtosatti@...hat.com>, linux-kernel@...r.kernel.org
CC:	Luiz Capitulino <lcapitulino@...hat.com>,
	Rik van Riel <riel@...hat.com>,
	Steven Rostedt <srostedt@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>, kvm@...r.kernel.org
Subject: Re: [patch -rt 2/2] KVM: lapic: mark LAPIC timer handler as irqsafe



On 25/11/2014 18:21, Marcelo Tosatti wrote:
> +
> +	if (r == HRTIMER_RESTART) {
> +		do {
> +			ret = hrtimer_start_expires(data, HRTIMER_MODE_ABS);
> +			if (ret == -ETIME)
> +				hrtimer_add_expires_ns(&ktimer->timer,
> +							ktimer->period);

Is it possible to just compute the time where the next interrupt
happens?  I suspect the printk and WARN_ON below can be easily triggered
by a guest.

Paolo

> +			i++;
> +		} while (ret == -ETIME && i < 10);
> +
> +		if (ret == -ETIME) {
> +			printk(KERN_ERR "%s: failed to reprogram timer\n",
> +			       __func__);
> +			WARN_ON(1);
> +		}
> +	}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/