diff options
| author | Tvrtko Ursulin <tvrtko.ursulin@intel.com> | 2017-10-17 18:09:08 +0300 |
|---|---|---|
| committer | Tvrtko Ursulin <tvrtko.ursulin@intel.com> | 2017-10-18 11:25:39 +0300 |
| commit | cb8d50dfb341e9615c8d203a3e6513dae9ff901d (patch) | |
| tree | 0c1d9aa4c26c37fed29ce5e98030105b2742c2ce /drivers/gpu/drm/i915/i915_gem_userptr.c | |
| parent | 930a784d02339be437fec07b3bb7213bde0ed53b (diff) | |
| download | linux-cb8d50dfb341e9615c8d203a3e6513dae9ff901d.tar.xz | |
drm/i915: Fixup userptr mmu notifier registration error handling
Avoid dereferencing the error pointer and also avoid returning NULL
from i915_mmu_notifier_find since the callers do not expect that.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 7741b547b6e0 ("drm/i915: Preallocate our mmu notifier workequeu to unbreak cpu hotplug deadlock")
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171017150908.12840-1-tvrtko.ursulin@linux.intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem_userptr.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_userptr.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c index cdc9be799eee..e26b23171b56 100644 --- a/drivers/gpu/drm/i915/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/i915_gem_userptr.c @@ -221,15 +221,17 @@ i915_mmu_notifier_find(struct i915_mm_struct *mm) /* Protected by mm_lock */ mm->mn = fetch_and_zero(&mn); } - } else { - /* someone else raced and successfully installed the mmu - * notifier, we can cancel our own errors */ + } else if (mm->mn) { + /* + * Someone else raced and successfully installed the mmu + * notifier, we can cancel our own errors. + */ err = 0; } mutex_unlock(&mm->i915->mm_lock); up_write(&mm->mm->mmap_sem); - if (mn) { + if (mn && !IS_ERR(mn)) { destroy_workqueue(mn->wq); kfree(mn); } |