linux-kernel - Re: [PATCH] x86, pci-hotplug, calgary / rio: fix EBDA ioremap()

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: <20080927163528.GD4600@elte.hu>
Date:	Sat, 27 Sep 2008 18:35:28 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Arjan van de Ven <arjan@...ux.intel.com>
Cc:	Suresh Siddha <suresh.b.siddha@...el.com>,
	Kenji Kaneshige <kaneshige.kenji@...fujitsu.com>,
	Linas Vepstas <linas@...tin.ibm.com>,
	"rajesh.shah@...el.com" <rajesh.shah@...el.com>,
	Greg Kroah-Hartman <gregkh@...e.de>,
	Kristen Accardi <kristen.c.accardi@...el.com>,
	Muli Ben-Yehuda <muli@...ibm.com>, jbarnes@...tuousgeek.org,
	tglx@...utronix.de, hpa@...or.com, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
	Yinghai Lu <yhlu.kernel@...il.com>
Subject: Re: [PATCH] x86, pci-hotplug, calgary / rio: fix EBDA ioremap()


* Arjan van de Ven <arjan@...ux.intel.com> wrote:

>>>
>>> mapping the EBDA is rather ... un-nice from that driver, so i guess  
>>> you check does the right thing in flagging possible crap.
>>
>> it does:
>>
>>     addr:  0x9f800
>>      end:  0xaf5e7
>> p->start:  0x9f800
>>   p->end:  0x9ffff
>>
>> resources are laid out like this:
>>
>>   0009f800-0009ffff : reserved
>>   000a0000-000bffff : Video RAM area
>>
>> so the driver over-maps into the Video RAM...
>
> ... and makes that uncachable (while it probably was WC before)

ah, neat angle, i did not consider that. One more entry into the '10 
good reasons why ioremap-ing RAM is bad' list.

	Ingo
--
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/