linux-kernel - Re: 2.6.29-rc powerpc G5 Xorg legacy

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] [day] [month] [year] [list]

Message-Id: <1232601370.23611.98.camel@pasglop>
Date:	Thu, 22 Jan 2009 16:16:10 +1100
From:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
To:	Hugh Dickins <hugh@...itas.com>
Cc:	Jesse Barnes <jbarnes@...tuousgeek.org>,
	"Rafael J. Wysocki" <rjw@...l.pl>, linuxppc-dev@...abs.org,
	linux-kernel@...r.kernel.org
Subject: Re: 2.6.29-rc powerpc G5 Xorg legacy_mem regression


> That's as far as I took it: I can see there's code to set up
> "Legacy VGA memory" but it looks like that's not coming into play.
> dmesg and .config attached: I think you'll get to the point much
> quicker than I would.
> 
> Though I bet you're busy at the moment: no hurry, I can comment
> out the pci_create_legacy_files() from drivers/pci/bus.c for now.

It's actually an X bug :-(

IE, I always create the legacy files, I just make mmap fail when legacy
VGA isn't available. This is the right way to do it, as it properly
informs X that yes, I do support the new API and no, there's no point in
trying to access legacy VGA memory on this machine.

I honestly don't see how I can fix that without making proper support
for legacy memory / IO impossible, and thus guaranteeing that X will
eternally continue to crap on random bits of /dev/mem in the future :-(

Cheers,
Ben.


--
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/