drm/i915: Use a slab for object allocation
The primary purpose of this was to debug some use-after-free memory
corruption that was causing an OOPS inside drm/i915. As it turned out
the corruption was being caused elsewhere and i915.ko as a major user of
many objects was being hit hardest.
Indeed as we do frequent the generic kmalloc caches, dedicating one to
ourselves (or at least naming one for us depending upon the core) aids
debugging our own slab usage.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 80ed751..2635ee6 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1736,6 +1736,9 @@
destroy_workqueue(dev_priv->wq);
+ if (dev_priv->slab)
+ kmem_cache_destroy(dev_priv->slab);
+
pci_dev_put(dev_priv->bridge_dev);
kfree(dev->dev_private);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d1d68f0..e2944e9 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -614,6 +614,7 @@
typedef struct drm_i915_private {
struct drm_device *dev;
+ struct kmem_cache *slab;
const struct intel_device_info *info;
@@ -1379,12 +1380,15 @@
int i915_gem_wait_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv);
void i915_gem_load(struct drm_device *dev);
+void *i915_gem_object_alloc(struct drm_device *dev);
+void i915_gem_object_free(struct drm_i915_gem_object *obj);
int i915_gem_init_object(struct drm_gem_object *obj);
void i915_gem_object_init(struct drm_i915_gem_object *obj,
const struct drm_i915_gem_object_ops *ops);
struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
size_t size);
void i915_gem_free_object(struct drm_gem_object *obj);
+
int __must_check i915_gem_object_pin(struct drm_i915_gem_object *obj,
uint32_t alignment,
bool map_and_fenceable,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 3de62b0..dfe7174 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -192,6 +192,18 @@
return 0;
}
+void *i915_gem_object_alloc(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ return kmem_cache_alloc(dev_priv->slab, GFP_KERNEL | __GFP_ZERO);
+}
+
+void i915_gem_object_free(struct drm_i915_gem_object *obj)
+{
+ struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
+ kmem_cache_free(dev_priv->slab, obj);
+}
+
static int
i915_gem_create(struct drm_file *file,
struct drm_device *dev,
@@ -215,7 +227,7 @@
if (ret) {
drm_gem_object_release(&obj->base);
i915_gem_info_remove_obj(dev->dev_private, obj->base.size);
- kfree(obj);
+ i915_gem_object_free(obj);
return ret;
}
@@ -3695,12 +3707,12 @@
struct address_space *mapping;
u32 mask;
- obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+ obj = i915_gem_object_alloc(dev);
if (obj == NULL)
return NULL;
if (drm_gem_object_init(dev, &obj->base, size) != 0) {
- kfree(obj);
+ i915_gem_object_free(obj);
return NULL;
}
@@ -3783,7 +3795,7 @@
i915_gem_info_remove_obj(dev_priv, obj->base.size);
kfree(obj->bit_17);
- kfree(obj);
+ i915_gem_object_free(obj);
}
int
@@ -4101,8 +4113,14 @@
void
i915_gem_load(struct drm_device *dev)
{
- int i;
drm_i915_private_t *dev_priv = dev->dev_private;
+ int i;
+
+ dev_priv->slab =
+ kmem_cache_create("i915_gem_object",
+ sizeof(struct drm_i915_gem_object), 0,
+ SLAB_HWCACHE_ALIGN,
+ NULL);
INIT_LIST_HEAD(&dev_priv->mm.active_list);
INIT_LIST_HEAD(&dev_priv->mm.inactive_list);
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 773ef77..defb888 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -276,8 +276,7 @@
if (IS_ERR(attach))
return ERR_CAST(attach);
-
- obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+ obj = i915_gem_object_alloc(dev);
if (obj == NULL) {
ret = -ENOMEM;
goto fail_detach;
@@ -285,7 +284,7 @@
ret = drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
if (ret) {
- kfree(obj);
+ i915_gem_object_free(obj);
goto fail_detach;
}
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 7299d63..f817b0c 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -252,7 +252,7 @@
{
struct drm_i915_gem_object *obj;
- obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+ obj = i915_gem_object_alloc(dev);
if (obj == NULL)
return NULL;
@@ -277,7 +277,7 @@
return obj;
cleanup:
- kfree(obj);
+ i915_gem_object_free(obj);
return NULL;
}