Using git tip of the X server, mesa, drm and intel, the X server always crashes the first time I run it after startup. It shows these messages:

(II) intel(0): [DRI] installation complete
(II) intel(0): [drm] dma control initialized, using IRQ 18
(EE) intel(0): Failed to mprotect ring buffer: Permission denied
(EE) intel(0): Failed to mprotect DRI memory manager: Permission denied
(II) intel(0): xf86BindGARTMemory: bind key 0 at 0x0b000000 (pgoffset 45056)
(EE) intel(0): Failed to mprotect exa offscreen: Permission denied
(II) intel(0): xf86BindGARTMemory: bind key 1 at 0x0e000000 (pgoffset 57344)
(EE) intel(0): Failed to mprotect classic textures: Permission denied
(EE) intel(0): Failed to mprotect depth buffer: Permission denied
(EE) intel(0): Failed to mprotect back buffer: Permission denied
(EE) intel(0): Failed to mprotect front buffer: Permission denied
(EE) intel(0): Failed to mprotect exa G965 state buffer: Permission denied
(EE) intel(0): Failed to mprotect logical 3D context: Permission denied
(EE) intel(0): Failed to mprotect HW cursors: Permission denied
(II) intel(0): Fixed memory allocation layout:

and eventually crashes with

Backtrace:
0: /usr/bin/X(xf86SigHandler+0x79) [0x80cffa9]
1: [0xffffe420]
2: /usr/lib/xorg/modules/drivers//intel_drv.so [0xb7a52f8b]
3: /usr/lib/xorg/modules/drivers//intel_drv.so [0xb7a54598]
4: /usr/bin/X(AddScreen+0x19d) [0x807078d]
5: /usr/bin/X(InitOutput+0x1c5) [0x80a6f15]
6: /usr/bin/X(main+0x281) [0x8070f01]
7: /lib/libc.so.6(__libc_start_main+0xe0) [0xb7bdd450]
8: /usr/bin/X(FontFileCompleteXLFD+0x1e9) [0x8070541]


If I start the server a second time, everything works fine. I'm not sure whether this is a problem in the X stack or somewhere else on my system (debian sid), but the problem appeared after upgrading X and company.