#ifndef __MAC802154_DRIVER_OPS
#define __MAC802154_DRIVER_OPS

#include <linux/types.h>
#include <linux/rtnetlink.h>

#include <net/mac802154.h>

#include "ieee802154_i.h"
#include "trace.h"

static inline int
drv_xmit_async(struct ieee802154_local *local, struct sk_buff *skb)
{
	return local->ops->xmit_async(&local->hw, skb);
}

static inline int
drv_xmit_sync(struct ieee802154_local *local, struct sk_buff *skb)
{
	might_sleep();

	return local->ops->xmit_sync(&local->hw, skb);
}

static inline int drv_start(struct ieee802154_local *local)
{
	int ret;

	might_sleep();

	trace_802154_drv_start(local);
	local->started = true;
	smp_mb();
	ret = local->ops->start(&local->hw);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline void drv_stop(struct ieee802154_local *local)
{
	might_sleep();

	trace_802154_drv_stop(local);
	local->ops->stop(&local->hw);
	trace_802154_drv_return_void(local);

	/* sync away all work on the tasklet before clearing started */
	tasklet_disable(&local->tasklet);
	tasklet_enable(&local->tasklet);

	barrier();

	local->started = false;
}

static inline int
drv_set_channel(struct ieee802154_local *local, u8 page, u8 channel)
{
	int ret;

	might_sleep();

	trace_802154_drv_set_channel(local, page, channel);
	ret = local->ops->set_channel(&local->hw, page, channel);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int drv_set_tx_power(struct ieee802154_local *local, s32 mbm)
{
	int ret;

	might_sleep();

	if (!local->ops->set_txpower) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	trace_802154_drv_set_tx_power(local, mbm);
	ret = local->ops->set_txpower(&local->hw, mbm);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int drv_set_cca_mode(struct ieee802154_local *local,
				   const struct wpan_phy_cca *cca)
{
	int ret;

	might_sleep();

	if (!local->ops->set_cca_mode) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	trace_802154_drv_set_cca_mode(local, cca);
	ret = local->ops->set_cca_mode(&local->hw, cca);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int drv_set_lbt_mode(struct ieee802154_local *local, bool mode)
{
	int ret;

	might_sleep();

	if (!local->ops->set_lbt) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	trace_802154_drv_set_lbt_mode(local, mode);
	ret = local->ops->set_lbt(&local->hw, mode);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int
drv_set_cca_ed_level(struct ieee802154_local *local, s32 mbm)
{
	int ret;

	might_sleep();

	if (!local->ops->set_cca_ed_level) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	trace_802154_drv_set_cca_ed_level(local, mbm);
	ret = local->ops->set_cca_ed_level(&local->hw, mbm);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int drv_set_pan_id(struct ieee802154_local *local, __le16 pan_id)
{
	struct ieee802154_hw_addr_filt filt;
	int ret;

	might_sleep();

	if (!local->ops->set_hw_addr_filt) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	filt.pan_id = pan_id;

	trace_802154_drv_set_pan_id(local, pan_id);
	ret = local->ops->set_hw_addr_filt(&local->hw, &filt,
					    IEEE802154_AFILT_PANID_CHANGED);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int
drv_set_extended_addr(struct ieee802154_local *local, __le64 extended_addr)
{
	struct ieee802154_hw_addr_filt filt;
	int ret;

	might_sleep();

	if (!local->ops->set_hw_addr_filt) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	filt.ieee_addr = extended_addr;

	trace_802154_drv_set_extended_addr(local, extended_addr);
	ret = local->ops->set_hw_addr_filt(&local->hw, &filt,
					    IEEE802154_AFILT_IEEEADDR_CHANGED);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int
drv_set_short_addr(struct ieee802154_local *local, __le16 short_addr)
{
	struct ieee802154_hw_addr_filt filt;
	int ret;

	might_sleep();

	if (!local->ops->set_hw_addr_filt) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	filt.short_addr = short_addr;

	trace_802154_drv_set_short_addr(local, short_addr);
	ret = local->ops->set_hw_addr_filt(&local->hw, &filt,
					    IEEE802154_AFILT_SADDR_CHANGED);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int
drv_set_pan_coord(struct ieee802154_local *local, bool is_coord)
{
	struct ieee802154_hw_addr_filt filt;
	int ret;

	might_sleep();

	if (!local->ops->set_hw_addr_filt) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	filt.pan_coord = is_coord;

	trace_802154_drv_set_pan_coord(local, is_coord);
	ret = local->ops->set_hw_addr_filt(&local->hw, &filt,
					    IEEE802154_AFILT_PANC_CHANGED);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int
drv_set_csma_params(struct ieee802154_local *local, u8 min_be, u8 max_be,
		    u8 max_csma_backoffs)
{
	int ret;

	might_sleep();

	if (!local->ops->set_csma_params) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	trace_802154_drv_set_csma_params(local, min_be, max_be,
					 max_csma_backoffs);
	ret = local->ops->set_csma_params(&local->hw, min_be, max_be,
					   max_csma_backoffs);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int
drv_set_max_frame_retries(struct ieee802154_local *local, s8 max_frame_retries)
{
	int ret;

	might_sleep();

	if (!local->ops->set_frame_retries) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	trace_802154_drv_set_max_frame_retries(local, max_frame_retries);
	ret = local->ops->set_frame_retries(&local->hw, max_frame_retries);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

static inline int
drv_set_promiscuous_mode(struct ieee802154_local *local, bool on)
{
	int ret;

	might_sleep();

	if (!local->ops->set_promiscuous_mode) {
		WARN_ON(1);
		return -EOPNOTSUPP;
	}

	trace_802154_drv_set_promiscuous_mode(local, on);
	ret = local->ops->set_promiscuous_mode(&local->hw, on);
	trace_802154_drv_return_int(local, ret);
	return ret;
}

#endif /* __MAC802154_DRIVER_OPS */
<div class='commit-subject'>drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()</div><div class='commit-msg'>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 &lt;daniel.vetter@intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Cc: Imre Deak &lt;imre.deak@intel.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>Diffstat</a> (limited to 'include/net/inet_frag.h')</div><table summary='diffstat' class='diffstat'>