f6e47884e7
Found by gem_stress. As we perform retirement from a workqueue, it is possible for us to free and unbind objects after the last close on the device, and so after the address space has been torn down and reset to NULL: BUG: unable to handle kernel NULL pointer dereference at 00000054 IP: [<c1295a20>] mutex_lock+0xf/0x27 *pde = 00000000 Oops: 0002 [#1] SMP last sysfs file: /sys/module/vt/parameters/default_utf8 Pid: 5, comm: kworker/u:0 Not tainted 2.6.38+ #214 EIP: 0060:[<c1295a20>] EFLAGS: 00010206 CPU: 1 EIP is at mutex_lock+0xf/0x27 EAX: 00000054 EBX: 00000054 ECX: 00000000 EDX: 00012fff ESI: 00000028 EDI: 00000000 EBP: f706fe20 ESP: f706fe18 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 Process kworker/u:0 (pid: 5, ti=f706e000 task=f7060d00 task.ti=f706e000) Stack: f5aa3c60 00000000 f706fe74 c107e7df 00000246 dea55380 00000054 f5aa3c60 f706fe44 00000061 f70b4000 c13fff84 00000008 f706fe54 00000000 00000000 00012f00 00012fff 00000028 c109e575 f6b36700 00100000 00000000 f706fe90 Call Trace: [<c107e7df>] unmap_mapping_range+0x7d/0x1e6 [<c109e575>] ? mntput_no_expire+0x52/0xb6 [<c11c12f6>] i915_gem_release_mmap+0x49/0x58 [<c11c3449>] i915_gem_object_unbind+0x4c/0x125 [<c11c353f>] i915_gem_free_object_tail+0x1d/0xdb [<c11c55a2>] i915_gem_free_object+0x3d/0x41 [<c11a6be2>] ? drm_gem_object_free+0x0/0x27 [<c11a6c07>] drm_gem_object_free+0x25/0x27 [<c113c3ca>] kref_put+0x39/0x42 [<c11c0a59>] drm_gem_object_unreference+0x16/0x18 [<c11c0b15>] i915_gem_object_move_to_inactive+0xba/0xbe [<c11c0c87>] i915_gem_retire_requests_ring+0x16e/0x1a5 [<c11c3645>] i915_gem_retire_requests+0x48/0x63 [<c11c36ac>] i915_gem_retire_work_handler+0x4c/0x117 [<c10385d1>] process_one_work+0x140/0x21b [<c103734c>] ? __need_more_worker+0x13/0x2a [<c10373b1>] ? need_to_create_worker+0x1c/0x35 [<c11c3660>] ? i915_gem_retire_work_handler+0x0/0x117 [<c1038faf>] worker_thread+0xd4/0x14b [<c1038edb>] ? worker_thread+0x0/0x14b [<c103be1b>] kthread+0x68/0x6d [<c103bdb3>] ? kthread+0x0/0x6d [<c12970f6>] kernel_thread_helper+0x6/0x10 Code: 00 e8 98 fe ff ff 5d c3 55 89 e5 3e 8d 74 26 00 ba 01 00 00 00 e8 84 fe ff ff 5d c3 55 89 e5 53 8d 64 24 fc 3e 8d 74 26 00 89 c3 <f0> ff 08 79 05 e8 ab ff ff ff 89 e0 25 00 e0 ff ff 89 43 10 58 EIP: [<c1295a20>] mutex_lock+0xf/0x27 SS:ESP 0068:f706fe18 CR2: 0000000000000054 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Keith Packard <keithp@keithp.com> |
||
|---|---|---|
| .. | ||
| i2c | ||
| i810 | ||
| i915 | ||
| mga | ||
| nouveau | ||
| r128 | ||
| radeon | ||
| savage | ||
| sis | ||
| tdfx | ||
| ttm | ||
| via | ||
| vmwgfx | ||
| ati_pcigart.c | ||
| drm_agpsupport.c | ||
| drm_auth.c | ||
| drm_buffer.c | ||
| drm_bufs.c | ||
| drm_cache.c | ||
| drm_context.c | ||
| drm_crtc_helper.c | ||
| drm_crtc.c | ||
| drm_debugfs.c | ||
| drm_dma.c | ||
| drm_dp_i2c_helper.c | ||
| drm_drv.c | ||
| drm_edid_modes.h | ||
| drm_edid.c | ||
| drm_encoder_slave.c | ||
| drm_fb_helper.c | ||
| drm_fops.c | ||
| drm_gem.c | ||
| drm_global.c | ||
| drm_hashtab.c | ||
| drm_info.c | ||
| drm_ioc32.c | ||
| drm_ioctl.c | ||
| drm_irq.c | ||
| drm_lock.c | ||
| drm_memory.c | ||
| drm_mm.c | ||
| drm_modes.c | ||
| drm_pci.c | ||
| drm_platform.c | ||
| drm_proc.c | ||
| drm_scatter.c | ||
| drm_sman.c | ||
| drm_stub.c | ||
| drm_sysfs.c | ||
| drm_trace_points.c | ||
| drm_trace.h | ||
| drm_usb.c | ||
| drm_vm.c | ||
| Kconfig | ||
| Makefile | ||
| README.drm | ||
************************************************************
* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
************************************************************
The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).
The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:
1. The DRM provides synchronized access to the graphics hardware via
the use of an optimized two-tiered lock.
2. The DRM enforces the DRI security policy for access to the graphics
hardware by only allowing authenticated X11 clients access to
restricted regions of memory.
3. The DRM provides a generic DMA engine, complete with multiple
queues and the ability to detect the need for an OpenGL context
switch.
4. The DRM is extensible via the use of small device-specific modules
that rely extensively on the API exported by the DRM module.
Documentation on the DRI is available from:
http://dri.freedesktop.org/wiki/Documentation
http://sourceforge.net/project/showfiles.php?group_id=387
http://dri.sourceforge.net/doc/
For specific information about kernel-level support, see:
The Direct Rendering Manager, Kernel Support for the Direct Rendering
Infrastructure
http://dri.sourceforge.net/doc/drm_low_level.html
Hardware Locking for the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/hardware_locking_low_level.html
A Security Analysis of the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/security_low_level.html