On 12/06/2012 03:46 PM, Dave Airlie wrote:

...

     ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");

@@ -817,6 +821,7 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages) &glob->kobj, "pool"); if (unlikely(ret != 0)) { kobject_put(&_manager->kobj);

•           kfree(_manager);
             _manager = NULL;
  

I don;t think this is, since the kobject_put shuold free it.

kobject_put only frees memory referenced by kobj, but not the memory pointed at by _manager.

rtg

Memory for _manager is allocated using kzalloc() but the result is not checked.

I was led to scrutinize ttm_page_alloc_init() from a smatch warning:

drivers/gpu/drm/ttm/ttm_page_alloc.c:799 ttm_page_alloc_init() error: potential null dereference '_manager'. (kzalloc returns null)

Cc: David Airlie airlied@linux.ie Cc: Dave Airlie airlied@redhat.com Cc: "Paul E. McKenney" paulmck@linux.vnet.ibm.com Cc: Zhao Yakui yakui.zhao@intel.com Cc: David Howells dhowells@redhat.com Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # 3.5+ Signed-off-by: Tim Gardner tim.gardner@canonical.com ---

This patch applies to stable 3.5 and newer.

V2 - kobject_put(&_manager->kobj) uses a destructor and container_of() to free _mamanger.

drivers/gpu/drm/ttm/ttm_page_alloc.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c index bd2a3b4..c64e96c 100644 --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c @@ -798,6 +798,10 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages) pr_info("Initializing pool allocator\n");

_manager = kzalloc(sizeof(*_manager), GFP_KERNEL); + if (!_manager) { + pr_err("ttm: Could not allocate _manager.\n"); + return -ENOMEM; + }

ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");