@@ -10093,20 +10093,17 @@ __intel_framebuffer_create(struct drm_device *dev,
int ret;
intel_fb = kzalloc(sizeof(*intel_fb), GFP_KERNEL);
- if (!intel_fb) {
- drm_gem_object_unreference(&obj->base);
+ if (!intel_fb)
return ERR_PTR(-ENOMEM);
- }
ret = intel_framebuffer_init(dev, intel_fb, mode_cmd, obj);
if (ret)
goto err;
return &intel_fb->base;
+
err:
- drm_gem_object_unreference(&obj->base);
kfree(intel_fb);
-
return ERR_PTR(ret);
}
@@ -10146,6 +10143,7 @@ intel_framebuffer_create_for_mode(struct drm_device *dev,
struct drm_display_mode *mode,
int depth, int bpp)
{
+ struct drm_framebuffer *fb;
struct drm_i915_gem_object *obj;
struct drm_mode_fb_cmd2 mode_cmd = { 0 };
@@ -10160,7 +10158,11 @@ intel_framebuffer_create_for_mode(struct drm_device *dev,
bpp);
mode_cmd.pixel_format = drm_mode_legacy_fb_format(bpp, depth);
- return intel_framebuffer_create(dev, &mode_cmd, obj);
+ fb = intel_framebuffer_create(dev, &mode_cmd, obj);
+ if (IS_ERR(fb))
+ drm_gem_object_unreference_unlocked(&obj->base);
+
+ return fb;
}
static struct drm_framebuffer *
@@ -14459,6 +14461,7 @@ intel_user_framebuffer_create(struct drm_device *dev,
struct drm_file *filp,
struct drm_mode_fb_cmd2 *mode_cmd)
{
+ struct drm_framebuffer *fb;
struct drm_i915_gem_object *obj;
obj = to_intel_bo(drm_gem_object_lookup(dev, filp,
@@ -14466,7 +14469,11 @@ intel_user_framebuffer_create(struct drm_device *dev,
if (&obj->base == NULL)
return ERR_PTR(-ENOENT);
- return intel_framebuffer_create(dev, mode_cmd, obj);
+ fb = intel_framebuffer_create(dev, mode_cmd, obj);
+ if (IS_ERR(fb))
+ drm_gem_object_unreference_unlocked(&obj->base);
+
+ return fb;
}
#ifndef CONFIG_DRM_FBDEV_EMULATION
Currently when allocating a framebuffer fails, the gem object gets unrefed at the bottom of the call stack in __intel_framebuffer_create, not where it gets refed, which is in intel_framebuffer_create_for_mode (via i915_gem_alloc_object) and in intel_user_framebuffer_create (via drm_gem_object_lookup). This invites mistakes: __intel_framebuffer_create is also called from intelfb_alloc, and as discovered by Tvrtko Ursulin, a double unref was introduced there with a8bb6818270c ("drm/i915: Fix error path leak in fbdev fb allocation"). As suggested by Ville Syrjälä, fix the double unref and improve code clarity by moving the unref away from __intel_framebuffer_create to where the gem object gets refed. Based on Tvrtko Ursulin's original v2. v3: On fb alloc failure, unref gem object where it gets refed, fix double unref in separate commit (Ville Syrjälä) v4: Lock struct_mutex on unref (Chris Wilson) v5: Rebase on drm-intel-nightly 2015y-09m-01d-09h-06m-08s UTC, rephrase commit message (Jani Nicula) Tested-by: Pierre Moreau <pierre.morrow@free.fr> [MBP 5,3 2009 nvidia MCP79 + G96 pre-retina] Tested-by: Paul Hordiienko <pvt.gord@gmail.com> [MBP 6,2 2010 intel ILK + nvidia GT216 pre-retina] Tested-by: William Brown <william@blackhats.net.au> [MBP 8,2 2011 intel SNB + amd turks pre-retina] Tested-by: Lukas Wunner <lukas@wunner.de> [MBP 9,1 2012 intel IVB + nvidia GK107 pre-retina] Tested-by: Bruno Bierbaumer <bruno@bierbaumer.net> [MBP 11,3 2013 intel HSW + nvidia GK107 retina] Fixes: a8bb6818270c ("drm/i915: Fix error path leak in fbdev fb allocation") Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> --- drivers/gpu/drm/i915/intel_display.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)