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staging: drm/omap: fix locking issue

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The create/free mmap offset code must be synchronized.  Yet only some
callers of omap_gem_mmap_offset() held struct_mutex.  Leading to various
crashes around drm_mm_insert_helper_range().  (In the free-object path,
which is currently the only place we drm_gem_free_mmap_offset(),
struct_mutex is already held.)

Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Rob Clark
2012-01-18 18:33:02 -06:00
committed by Greg Kroah-Hartman
parent a9e8d70c1a
commit c5b1247bd1
1 changed files with 14 additions and 4 deletions
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18
drivers/staging/omapdrm/omap_gem.c
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@@ -116,6 +116,9 @@ struct omap_gem_object {
} *sync; } *sync;
}; };
static int get_pages(struct drm_gem_object *obj, struct page ***pages);
static uint64_t mmap_offset(struct drm_gem_object *obj);
/* To deal with userspace mmap'ings of 2d tiled buffers, which (a) are /* To deal with userspace mmap'ings of 2d tiled buffers, which (a) are
* not necessarily pinned in TILER all the time, and (b) when they are * not necessarily pinned in TILER all the time, and (b) when they are
* they are not necessarily page aligned, we reserve one or more small * they are not necessarily page aligned, we reserve one or more small
@@ -149,7 +152,7 @@ static void evict_entry(struct drm_gem_object *obj,
{ {
if (obj->dev->dev_mapping) { if (obj->dev->dev_mapping) {
size_t size = PAGE_SIZE * usergart[fmt].height; size_t size = PAGE_SIZE * usergart[fmt].height;
loff_t off = omap_gem_mmap_offset(obj) + loff_t off = mmap_offset(obj) +
(entry->obj_pgoff << PAGE_SHIFT); (entry->obj_pgoff << PAGE_SHIFT);
unmap_mapping_range(obj->dev->dev_mapping, off, size, 1); unmap_mapping_range(obj->dev->dev_mapping, off, size, 1);
} }
@@ -189,8 +192,6 @@ static inline bool is_shmem(struct drm_gem_object *obj)
return obj->filp != NULL; return obj->filp != NULL;
} }
static int get_pages(struct drm_gem_object *obj, struct page ***pages);
static DEFINE_SPINLOCK(sync_lock); static DEFINE_SPINLOCK(sync_lock);
/** ensure backing pages are allocated */ /** ensure backing pages are allocated */
@@ -251,7 +252,7 @@ static void omap_gem_detach_pages(struct drm_gem_object *obj)
} }
/** get mmap offset */ /** get mmap offset */
uint64_t omap_gem_mmap_offset(struct drm_gem_object *obj) static uint64_t mmap_offset(struct drm_gem_object *obj)
{ {
if (!obj->map_list.map) { if (!obj->map_list.map) {
/* Make it mmapable */ /* Make it mmapable */
@@ -267,6 +268,15 @@ uint64_t omap_gem_mmap_offset(struct drm_gem_object *obj)
return (uint64_t)obj->map_list.hash.key << PAGE_SHIFT; return (uint64_t)obj->map_list.hash.key << PAGE_SHIFT;
} }
uint64_t omap_gem_mmap_offset(struct drm_gem_object *obj)
{
uint64_t offset;
mutex_lock(&obj->dev->struct_mutex);
offset = mmap_offset(obj);
mutex_unlock(&obj->dev->struct_mutex);
return offset;
}
/** get mmap size */ /** get mmap size */
size_t omap_gem_mmap_size(struct drm_gem_object *obj) size_t omap_gem_mmap_size(struct drm_gem_object *obj)
{ {