From c5b1247bd1c3ab6722acfa95213be9a16bfb664c Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Wed, 18 Jan 2012 18:33:02 -0600 Subject: [PATCH] staging: drm/omap: fix locking issue 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 Signed-off-by: Greg Kroah-Hartman --- drivers/staging/omapdrm/omap_gem.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/staging/omapdrm/omap_gem.c b/drivers/staging/omapdrm/omap_gem.c index ae1ad35..b7d6f88 100644 --- a/drivers/staging/omapdrm/omap_gem.c +++ b/drivers/staging/omapdrm/omap_gem.c @@ -116,6 +116,9 @@ struct omap_gem_object { } *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 * 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 @@ -149,7 +152,7 @@ static void evict_entry(struct drm_gem_object *obj, { if (obj->dev->dev_mapping) { 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); 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; } -static int get_pages(struct drm_gem_object *obj, struct page ***pages); - static DEFINE_SPINLOCK(sync_lock); /** ensure backing pages are allocated */ @@ -251,7 +252,7 @@ static void omap_gem_detach_pages(struct drm_gem_object *obj) } /** 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) { /* 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; } +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 */ size_t omap_gem_mmap_size(struct drm_gem_object *obj) { -- 2.7.4