linux-kernel - Re: [PATCH] x86: ioapic needs check attr when programmed more than once

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: <CAFgQCTuZ2ojrgvW3McDtrrVu06J1d9ssdfu4fD3Pb7rCYL2MHA@mail.gmail.com>
Date:	Fri, 23 Aug 2013 16:04:32 +0800
From:	Liu ping fan <kernelfans@...il.com>
To:	Ingo Molnar <mingo@...nel.org>
Cc:	x86@...nel.org, linux-kernel@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, Kevin Hao <haokexin@...il.com>
Subject: Re: [PATCH] x86: ioapic needs check attr when programmed more than once

On Fri, Aug 23, 2013 at 3:30 PM, Ingo Molnar <mingo@...nel.org> wrote:
>
> * Liu Ping Fan <kernelfans@...il.com> wrote:
>
>> When programming ioapic pinX more than once, current code
>> does not check whether the later attr (trigger&polarity) is the
>> same as the former or not. This causes a broken semantic.
>>
>> Fix it by reporting -EBUSY, when attr is different.
>
> Was this observed in real life somehow, and if yes, what is
> the before/after behavior?
>
Using qemu q35 machine, I found the ioapic's ioredtbl[] will never has
low-active, even the hpet driver registered it. After tracing, I found
it shared a high-level active IRQ line with other device. So in fact,
the acpi_register_gsi(, ACPI_ACTIVE_LOW) in hpet driver fail, but it
did not detect it.
The effect in qemu: when hpet-dev assert low-level, the kernel can not respond.


Thanks,
Pingfan
--
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/