config USBIP_CORE tristate "USB/IP support" depends on NET select USB_COMMON ---help--- This enables pushing USB packets over IP to allow remote machines direct access to USB devices. It provides the USB/IP core that is required by both drivers. For more details, and to get the userspace utility programs, please see . To compile this as a module, choose M here: the module will be called usbip-core. If unsure, say N. config USBIP_VHCI_HCD tristate "VHCI hcd" depends on USBIP_CORE && USB ---help--- This enables the USB/IP virtual host controller driver, which is run on the remote machine. To compile this driver as a module, choose M here: the module will be called vhci-hcd. config USBIP_VHCI_HC_PORTS int "Number of ports per USB/IP virtual host controller" range 1 31 default 8 depends on USBIP_VHCI_HCD ---help--- To increase number of ports available for USB/IP virtual host controller driver, this defines number of ports per USB/IP virtual host controller. config USBIP_VHCI_NR_HCS int "Number of USB/IP virtual host controllers" range 1 128 default 1 depends on USBIP_VHCI_HCD ---help--- To increase number of ports available for USB/IP virtual host controller driver, this defines number of USB/IP virtual host controllers as if adding physical host controllers. config USBIP_HOST tristate "Host driver" depends on USBIP_CORE && USB ---help--- This enables the USB/IP host driver, which is run on the machine that is sharing the USB devices. To compile this driver as a module, choose M here: the module will be called usbip-host. config USBIP_VUDC tristate "VUDC driver" depends on USBIP_CORE && USB_GADGET ---help--- This enables the USB/IP virtual USB device controller driver, which is run on the host machine, allowing the machine itself to act as a device. To compile this driver as a module, choose M here: the module will be called usbip-vudc. config USBIP_DEBUG bool "Debug messages for USB/IP" depends on USBIP_CORE ---help--- This enables the debug messages from the USB/IP drivers. e&id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>commitdiff
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authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800
commit39cb2c9a316e77f6dfba96c543e55b6672d5a37e (patch)
tree98fe974ee4e20121253de7f61fc8d01bdb3821c1 /kernel/time/timekeeping_debug.c
parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/time/timekeeping_debug.c')