dri ioctl32 problem on amd64/x86_64 on 2.6.8-rc2 and earlier

[phil.stewart@lichp.co.uk]

I have a working direct rendering mechanism in my 64-bit userland. However,
32-bit software running in a 32-bit chroot environment cannot operate with the
64-bit drm. I get the following error when executing the 32-bit glxinfo inside
the chroot:

# /usr/X11R6/bin/glxinfo
name of display: :0.0
libGL error: failed to open DRM: Operation not permitted
libGL error: reverting to (slow) indirect rendering
display: :0  screen: 0
direct rendering: No

This generates the following entry in kernel messages:

Jul 20 21:18:46 gordon ioctl32(glxinfo:12562): Unknown cmd fd(4)
cmd(c0086401){00} arg(bffff0f0) on /dev/dri/card0

Similarly for the 32-bit glxgears:

Jul 20 21:21:21 gordon ioctl32(glxgears:12567): Unknown cmd fd(4)
cmd(c0086401){00} arg(bfffeff0) on /dev/dri/card0

Kernels versions tested (all consistently produce the same error):
2.6.8-rc2
2.6.7-mm6
2.6.7-gentoo-r11

System hardware:
1x AMD Opteron 242
AMD 8151/8111 chipset
Radeon RV100 graphics card

Output of lspci -v regarding graphics card:
0000:02:00.0 VGA compatible controller: ATI Technologies Inc Radeon RV100 QY
[Radeon 7000/VE] (prog-if 00 [VGA])
        Subsystem: PC Partner Limited RV100 QY [Sapphire Radeon VE 7000]
        Flags: bus master, stepping, 66Mhz, medium devsel, latency 64, IRQ 16
        Memory at e0000000 (32-bit, prefetchable) [size=ff5c0000]
        I/O ports at b800 [size=256]
        Memory at ff5f0000 (32-bit, non-prefetchable) [size=64K]
        Expansion ROM at 00020000 [disabled]
        Capabilities: [58] AGP version 2.0
        Capabilities: [50] Power Management version 2

Output of scripts/ver_linux:
Linux gordon 2.6.8-rc2 #1 Tue Jul 20 20:37:41 BST 2004 x86_64 5  GNU/Linux
  
Gnu C                  3.3.3
Gnu make               3.80
binutils               2.15.90.0.1.1
util-linux             2.12
mount                  2.12
module-init-tools      3.0
e2fsprogs              1.35
Linux C Library        2.3.4
Dynamic linker (ldd)   2.3.4
Procps                 3.2.1
Net-tools              1.60
Kbd                    1.12
Sh-utils               5.2.1
Modules Loaded         radeon eth1394 snd_seq_midi snd_seq_midi_event snd_seq
ohci1394 ieee1394 snd_pcm_oss snd_mixer_oss snd_cs46xx snd_rawmidi
snd_seq_device snd_ac97_codec snd_pcm snd_timer snd snd_page_alloc budget
budget_core dvb_core saa7146 ttpci_eeprom e1000

Please keep me CC'd in if more information is required.

--
Phil Stewart