linux/drivers/gpu/drm
Imre Deak bcdb72ac7c drm/i915: fix pch pci device enumeration
pci_get_class(class, from) drops the refcount for 'from', so the
extra pci_dev_put we do on it will result in a use after free bug
starting with the WARN below.

Regression introduced in

commit 6a9c4b35e6
Author: Rui Guo <firemeteor@users.sourceforge.net>
Date:   Wed Jun 19 21:10:23 2013 +0800

    drm/i915: Fix PCH detect with multiple ISA bridges in VM

[  164.338460] WARNING: CPU: 1 PID: 2094 at include/linux/kref.h:47 klist_next+0xae/0x110()
[  164.347731] CPU: 1 PID: 2094 Comm: modprobe Tainted: G           O 3.13.0-imre+ #354
[  164.356468] Hardware name: Intel Corp. VALLEYVIEW B0 PLATFORM/NOTEBOOK, BIOS BYTICRB1.X64.0062.R70.1310112051 10/11/2013
[  164.368796] Call Trace:
[  164.371609]  [<ffffffff816a32a6>] dump_stack+0x4e/0x7a
[  164.377447]  [<ffffffff8104f75d>] warn_slowpath_common+0x7d/0xa0
[  164.384238]  [<ffffffff8104f83a>] warn_slowpath_null+0x1a/0x20
[  164.390851]  [<ffffffff8169aeae>] klist_next+0xae/0x110
[  164.396777]  [<ffffffff8130a110>] ? pci_do_find_bus+0x70/0x70
[  164.403286]  [<ffffffff813cb4a9>] bus_find_device+0x89/0xc0
[  164.409719]  [<ffffffff8130a373>] pci_get_dev_by_id+0x63/0xa0
[  164.416238]  [<ffffffff8130a4e4>] pci_get_class+0x44/0x50
[  164.422433]  [<ffffffffa034821f>] intel_dsm_detect+0x16f/0x1f0 [i915]
[  164.429801]  [<ffffffffa03482ae>] intel_register_dsm_handler+0xe/0x10 [i915]
[  164.437831]  [<ffffffffa02d30fe>] i915_driver_load+0xafe/0xf30 [i915]
[  164.445126]  [<ffffffff8158a150>] ? intel_alloc_coherent+0x110/0x110
[  164.452340]  [<ffffffffa0148c07>] drm_dev_register+0xc7/0x150 [drm]
[  164.459462]  [<ffffffffa014b23f>] drm_get_pci_dev+0x11f/0x1f0 [drm]
[  164.466554]  [<ffffffff816abb81>] ? _raw_spin_unlock_irqrestore+0x51/0x70
[  164.474287]  [<ffffffffa02cf7a6>] i915_pci_probe+0x56/0x60 [i915]
[  164.481185]  [<ffffffff8130a028>] pci_device_probe+0x78/0xf0
[  164.487603]  [<ffffffff813cd495>] driver_probe_device+0x155/0x350
[  164.494505]  [<ffffffff813cd74e>] __driver_attach+0x6e/0xa0
[  164.500826]  [<ffffffff813cd6e0>] ? __device_attach+0x50/0x50
[  164.507333]  [<ffffffff813cb2be>] bus_for_each_dev+0x6e/0xc0
[  164.513752]  [<ffffffff813ccefe>] driver_attach+0x1e/0x20
[  164.519870]  [<ffffffff813cc958>] bus_add_driver+0x138/0x260
[  164.526289]  [<ffffffffa0188000>] ? 0xffffffffa0187fff
[  164.532116]  [<ffffffff813cde78>] driver_register+0x98/0xe0
[  164.538558]  [<ffffffffa0188000>] ? 0xffffffffa0187fff
[  164.544389]  [<ffffffff813087b0>] __pci_register_driver+0x60/0x70
[  164.551336]  [<ffffffffa014b37d>] drm_pci_init+0x6d/0x120 [drm]
[  164.558040]  [<ffffffffa0188000>] ? 0xffffffffa0187fff
[  164.563928]  [<ffffffffa018806a>] i915_init+0x6a/0x6c [i915]
[  164.570363]  [<ffffffff810002da>] do_one_initcall+0xaa/0x160
[  164.576783]  [<ffffffff8103b140>] ? set_memory_nx+0x40/0x50
[  164.583100]  [<ffffffff810ce7f5>] load_module+0x1fb5/0x2550
[  164.589410]  [<ffffffff810caab0>] ? store_uevent+0x40/0x40
[  164.595628]  [<ffffffff810cee7d>] SyS_init_module+0xed/0x100
[  164.602048]  [<ffffffff816b3c52>] system_call_fastpath+0x16/0x1b

v2: simplify the loop further (Chris)

Signed-off-by: Imre Deak <imre.deak@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reported-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65652
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=74161
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2014-03-03 11:51:16 +02:00
..
armada Merge branch 'drm-armada-fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-cubox into drm-next 2014-01-29 09:38:32 +10:00
ast drm/mgag200,ast,cirrus: fix regression with drm_can_sleep conversion 2014-02-06 11:39:03 +10:00
bochs drm/bochs: new driver 2013-12-23 11:02:39 +10:00
cirrus drm/mgag200,ast,cirrus: fix regression with drm_can_sleep conversion 2014-02-06 11:39:03 +10:00
exynos drm/exynos: Convert to use the standard hdmi.h header 2014-02-07 10:48:12 +09:00
gma500 Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2014-01-29 20:49:12 -08:00
i2c drm/i2c: tda998x: Fix memory leak in tda998x_encoder_init error path. 2014-02-13 19:40:24 +00:00
i810 drm: kill DRIVER_REQUIRE_AGP 2013-12-18 11:17:53 +10:00
i915 drm/i915: fix pch pci device enumeration 2014-03-03 11:51:16 +02:00
mga drivers: gpu: Include appropriate header file in mga_ioc32.c 2014-01-14 12:59:24 +10:00
mgag200 drm/mgag200,ast,cirrus: fix regression with drm_can_sleep conversion 2014-02-06 11:39:03 +10:00
msm Merge branch 'msm-next' of git://people.freedesktop.org/~robclark/linux into drm-next 2014-02-11 12:56:17 +10:00
nouveau ACPI and power management fixes for 3.14-rc4 2014-02-21 10:01:17 -08:00
omapdrm omapdrm patches for 3.14 2014-01-29 09:37:47 +10:00
panel drm/panel: update EDID BLOB in panel_simple_get_modes() 2014-01-14 16:02:02 +01:00
qxl Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2014-01-29 20:49:12 -08:00
r128 drivers: gpu: Include appropriate header file in r128_ioc32.c 2014-01-14 13:05:37 +10:00
radeon drm/radeon: enable speaker allocation setup on dce3.2 2014-02-27 14:21:37 -05:00
rcar-du Merge branch 'drm/next/du' of git://linuxtv.org/pinchartl/fbdev into drm-next 2013-12-23 10:42:36 +10:00
savage drm: Kill DRM_*MEMORYBARRIER 2013-12-18 11:35:21 +10:00
shmobile drm/shmob: call drm_put_dev directly from ->remove hook 2013-12-18 11:05:46 +10:00
sis drivers: gpu: Mark function as static in sis_drv.c 2014-01-14 13:04:33 +10:00
tdfx
tegra drm/tegra: Add guard to avoid double disable/enable of RGB outputs 2014-02-12 07:50:38 +01:00
tilcdc drm: store the gem vma offset manager in a typed pointer 2014-01-14 12:38:32 +10:00
ttm drm/ttm: Fix memory leak in ttm_agp_backend.c 2014-02-18 14:03:32 +01:00
udl drm: Push dirtyfb ioctl kms locking down to drivers 2013-12-18 10:49:08 +10:00
via drivers: gpu: Mark function as static in via_drv.c 2014-01-14 13:05:00 +10:00
vmwgfx drm/vmwgfx: avoid null pointer dereference at failure paths 2014-03-02 09:49:59 +01:00
ati_pcigart.c
drm_agpsupport.c drm: rip out DRM_AGP_MEM and DRM_AGP_KERN 2013-12-18 11:32:55 +10:00
drm_auth.c
drm_buffer.c drm: Kill DRM_COPY_(TO|FROM)_USER 2013-12-18 11:35:01 +10:00
drm_bufs.c drm: rip out drm_core_has_AGP 2013-12-18 11:20:04 +10:00
drm_cache.c
drm_context.c
drm_crtc_helper.c drm/tegra: Changes for v3.14-rc1 (update) 2014-01-29 12:03:56 +10:00
drm_crtc.c drm/tegra: Changes for v3.14-rc1 (update) 2014-01-29 12:03:56 +10:00
drm_debugfs.c
drm_dma.c
drm_dp_helper.c
drm_drv.c drm: Kill file_priv->ioctl_count tracking 2013-12-18 11:42:13 +10:00
drm_edid_load.c drm/edid: Make edid_load() return a void * 2013-12-18 10:42:13 +10:00
drm_edid.c drm/edid: Populate picture aspect ratio for CEA modes 2014-01-20 18:32:21 +01:00
drm_encoder_slave.c
drm_fb_cma_helper.c
drm_fb_helper.c drm: do not steal the display if we have a master 2013-12-18 10:47:20 +10:00
drm_flip_work.c
drm_fops.c drm: remove dev->vma_count 2013-12-18 11:43:29 +10:00
drm_gem_cma_helper.c
drm_gem.c drm/gem: Always initialize the gem object in object_init 2014-01-21 10:19:58 +01:00
drm_global.c
drm_hashtab.c
drm_info.c drm: remove dev->vma_count 2013-12-18 11:43:29 +10:00
drm_ioc32.c
drm_ioctl.c drm: add DRM_CAPs for cursor size 2014-02-18 13:41:01 -05:00
drm_irq.c drm/radeon: Move the early vblank IRQ fixup to radeon_get_crtc_scanoutpos() 2014-01-20 12:21:35 +02:00
drm_lock.c
drm_memory.c drm: rip out DRM_AGP_MEM and DRM_AGP_KERN 2013-12-18 11:32:55 +10:00
drm_mipi_dsi.c drm: Add MIPI DSI bus support 2013-12-17 18:09:43 +01:00
drm_mm.c
drm_modes.c Revert "drm: copy mode type in drm_mode_connector_list_update()" 2014-01-14 12:50:49 +10:00
drm_panel.c drm: Add panel support 2013-12-17 18:09:46 +01:00
drm_pci.c drm: remove global_mutex locking around agp_init 2013-12-18 11:27:29 +10:00
drm_platform.c drm: restrict the device list for shadow attached drivers 2013-12-18 11:08:36 +10:00
drm_prime.c
drm_rect.c
drm_scatter.c
drm_stub.c Merge branch 'drm-intel-next' of git://people.freedesktop.org/~danvet/drm-intel into drm-next 2014-01-20 10:21:54 +10:00
drm_sysfs.c
drm_trace_points.c
drm_trace.h
drm_usb.c drivers: gpu: Include appropriate header file in drm_usb.c 2014-01-14 12:53:41 +10:00
drm_vm.c drm: remove dev->vma_count 2013-12-18 11:43:29 +10:00
drm_vma_manager.c
Kconfig drm/bochs: new driver 2013-12-23 11:02:39 +10:00
Makefile drm/bochs: new driver 2013-12-23 11:02:39 +10:00
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