#ifndef _XEN_PLATFORM_PCI_H
#define _XEN_PLATFORM_PCI_H
#define XEN_IOPORT_MAGIC_VAL 0x49d2
#define XEN_IOPORT_LINUX_PRODNUM 0x0003
#define XEN_IOPORT_LINUX_DRVVER 0x0001
#define XEN_IOPORT_BASE 0x10
#define XEN_IOPORT_PLATFLAGS (XEN_IOPORT_BASE + 0) /* 1 byte access (R/W) */
#define XEN_IOPORT_MAGIC (XEN_IOPORT_BASE + 0) /* 2 byte access (R) */
#define XEN_IOPORT_UNPLUG (XEN_IOPORT_BASE + 0) /* 2 byte access (W) */
#define XEN_IOPORT_DRVVER (XEN_IOPORT_BASE + 0) /* 4 byte access (W) */
#define XEN_IOPORT_SYSLOG (XEN_IOPORT_BASE + 2) /* 1 byte access (W) */
#define XEN_IOPORT_PROTOVER (XEN_IOPORT_BASE + 2) /* 1 byte access (R) */
#define XEN_IOPORT_PRODNUM (XEN_IOPORT_BASE + 2) /* 2 byte access (W) */
#define XEN_UNPLUG_ALL_IDE_DISKS (1<<0)
#define XEN_UNPLUG_ALL_NICS (1<<1)
#define XEN_UNPLUG_AUX_IDE_DISKS (1<<2)
#define XEN_UNPLUG_ALL (XEN_UNPLUG_ALL_IDE_DISKS|\
XEN_UNPLUG_ALL_NICS|\
XEN_UNPLUG_AUX_IDE_DISKS)
#define XEN_UNPLUG_UNNECESSARY (1<<16)
#define XEN_UNPLUG_NEVER (1<<17)
static inline int xen_must_unplug_nics(void) {
#if (defined(CONFIG_XEN_NETDEV_FRONTEND) || \
defined(CONFIG_XEN_NETDEV_FRONTEND_MODULE)) && \
defined(CONFIG_XEN_PVHVM)
return 1;
#else
return 0;
#endif
}
static inline int xen_must_unplug_disks(void) {
#if (defined(CONFIG_XEN_BLKDEV_FRONTEND) || \
defined(CONFIG_XEN_BLKDEV_FRONTEND_MODULE)) && \
defined(CONFIG_XEN_PVHVM)
return 1;
#else
return 0;
#endif
}
#if defined(CONFIG_XEN_PVHVM)
extern bool xen_has_pv_devices(void);
extern bool xen_has_pv_disk_devices(void);
extern bool xen_has_pv_nic_devices(void);
extern bool xen_has_pv_and_legacy_disk_devices(void);
#else
static inline bool xen_has_pv_devices(void)
{
return IS_ENABLED(CONFIG_XEN);
}
static inline bool xen_has_pv_disk_devices(void)
{
return IS_ENABLED(CONFIG_XEN);
}
static inline bool xen_has_pv_nic_devices(void)
{
return IS_ENABLED(CONFIG_XEN);
}
static inline bool xen_has_pv_and_legacy_disk_devices(void)
{
return false;
}
#endif
#endif /* _XEN_PLATFORM_PCI_H */
de/pcmcia/ds.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>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>