drm/i915: Use unsigned long for obj->user_pin_count

At least on linux sizeof(long) == sizeof(void*) and the thinking
is that you can grab about as many references as there's memory.

Doesn't really matter, just a bit of OCD since the fixed size data
type in a pure in-kernel datastructure look off.

v2: Ville asked for an overflow check since no one prevents userspace
from incrementing the pin count forever.

v3: s/INT/LONG/, noticed by Chris.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 6 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 759de9f123fd..e4ff8e91d939 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1604,7 +1604,7 @@ struct drm_i915_gem_object {
         unsigned long *bit_17;
 
         /** User space pin count and filp owning the pin */
-        uint32_t user_pin_count;
+        unsigned long user_pin_count;
         struct drm_file *pin_filp;
 
         /** for phy allocated objects */
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f10ae6498bce..34df59b660f8 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3931,6 +3931,11 @@ i915_gem_pin_ioctl(struct drm_device *dev, void *data,
                 goto out;
         }
 
+        if (obj->user_pin_count == ULONG_MAX) {
+                ret = -EBUSY;
+                goto out;
+        }
+
         if (obj->user_pin_count == 0) {
                 ret = i915_gem_obj_ggtt_pin(obj, args->alignment, true, false);
                 if (ret)