From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Date: Mon, 28 May 2007 15:07:14 +0000 Subject: Re: [patch 4/5] ia64: fail mmaps that span areas with incompatible attributes Message-Id: <200705280907.14687.bjorn.helgaas@hp.com> List-Id: References: <200703211622.05198.bjorn.helgaas@hp.com> In-Reply-To: <200703211622.05198.bjorn.helgaas@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Sunday 27 May 2007 08:55:45 pm Peter Chubb wrote: > >>>>> "Peter" = Peter Chubb writes: > > >>>>> "Bjorn" = Bjorn Helgaas writes: > > Bjorn> Example memory map (from HP sx1000 with VGA enabled): 0x00000 - > Bjorn> 0x9FFFF supports only WB (cacheable) access 0xA0000 - 0xBFFFF > Bjorn> supports only UC (uncacheable) access 0xC0000 - 0xFFFFF > Bjorn> supports only WB (cacheable) access > > Bjorn> Some versions of X map the entire 0x00000-0xFFFFF area at once. > Bjorn> With the example above, this mmap must fail because there's no > Bjorn> memory attribute that's safe for the entire area. > > Peter> This patch breaks X on a ZX2000. > > Except that there is a fix in the latest X source. > > Sorry to bother you all. No problem, I should have mentioned the X server interlock in the changelog, which would have saved you the trouble of debugging this. This whole area has been an incredible headache, and I recently discovered yet another hole to be fixed (mmap via /proc/bus/pci needs to be checked, iirc). Bjorn