Today, I installed Gentoo's latest stable kernel "2.4.20-gentoo-r1" which includes the GR security patches. I have enabled the kmem protection of the GR security patches, which prohibits writing to /dev/kmem and /dev/mem (and also mmapping them for write) and opening /dev/port, but - according to the documentation - specifically allows xfree to mmap video memory.

With the new kernel, xfree fails to start:
* First, it gives an error message about being unable to access the BIOS:
(EE) RADEON(0): Cannot map SYS BIOS
* Then, it gives up with the following message:
Fatal server error:
xf86MapVidMem: Could not mmap framebuffer (0x00000000,0x1000) (Operation not permitted)


(Note that the mapped address is 0, which looks extremely strange to me!)

The same configuration (also with grsec's kmem switched on!) worked fine for me with the previous Gentoo kernel (2.4.19-r10) and the same xfree. It also works with the new kernel if kmem protection is disabled.

This is on a sony notebook with an ATI M7.

Questions:
* Does xfree mmap the BIOS read/write and why?
* What consequences will it have if the BIOS is not accessible (on a notebook, with the builtin flat panel).
* Is the strange framebuffer mmap a consequence of the BIOS problem?
* Any tips or help concerning grsec and xfree?


Many thanks in advance!

--
DI. Dr. Klaus Kusche
Email: [EMAIL PROTECTED]        WWW: http://members.inode.at/kusche
Phone @ home: +43 7234 83894             Phone @ work: +43 732 673368 0
Private address:               Buchenweg 15, A-4100 Ottensheim, Austria
Office address: HTBLA Leonding, Limesstr. 12-14, 4060 Leonding, Austria
                or  HTBLA Traun, Holzbauernstr. 20, 4050 Traun, Austria

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