drm/ttm: fix invalid NULL deref

The BO might be NULL in this function, use the bdev directly.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Colin Ian King <colin.king@canonical.com>
Fixes: a1f091f8ef2b ("drm/ttm: switch to per device LRU lock")
Link: https://patchwork.freedesktop.org/patch/msgid/20210325152740.82633-1-christian.koenig@amd.com

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 2d2ac53..6ab7b66 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -625,7 +625,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
        unsigned i;
        int ret;
 
-       spin_lock(&bo->bdev->lru_lock);
+       spin_lock(&bdev->lru_lock);
        for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
                list_for_each_entry(bo, &man->lru[i], lru) {
                        bool busy;
@@ -662,7 +662,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
        if (!bo) {
                if (busy_bo && !ttm_bo_get_unless_zero(busy_bo))
                        busy_bo = NULL;
-               spin_unlock(&bo->bdev->lru_lock);
+               spin_unlock(&bdev->lru_lock);
                ret = ttm_mem_evict_wait_busy(busy_bo, ctx, ticket);
                if (busy_bo)
                        ttm_bo_put(busy_bo);
@@ -676,7 +676,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
                return ret;
        }
 
-       spin_unlock(&bo->bdev->lru_lock);
+       spin_unlock(&bdev->lru_lock);
 
        ret = ttm_bo_evict(bo, ctx);
        if (locked)