diff options
Diffstat (limited to 'drivers/dma-buf/dma-resv.c')
| -rw-r--r-- | drivers/dma-buf/dma-resv.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 709002515550..4264e64788c4 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -34,6 +34,7 @@ #include <linux/dma-resv.h> #include <linux/export.h> +#include <linux/sched/mm.h> /** * DOC: Reservation Object Overview @@ -95,6 +96,37 @@ static void dma_resv_list_free(struct dma_resv_list *list) kfree_rcu(list, rcu); } +#if IS_ENABLED(CONFIG_LOCKDEP) +static int __init dma_resv_lockdep(void) +{ + struct mm_struct *mm = mm_alloc(); + struct ww_acquire_ctx ctx; + struct dma_resv obj; + int ret; + + if (!mm) + return -ENOMEM; + + dma_resv_init(&obj); + + down_read(&mm->mmap_sem); + ww_acquire_init(&ctx, &reservation_ww_class); + ret = dma_resv_lock(&obj, &ctx); + if (ret == -EDEADLK) + dma_resv_lock_slow(&obj, &ctx); + fs_reclaim_acquire(GFP_KERNEL); + fs_reclaim_release(GFP_KERNEL); + ww_mutex_unlock(&obj.lock); + ww_acquire_fini(&ctx); + up_read(&mm->mmap_sem); + + mmput(mm); + + return 0; +} +subsys_initcall(dma_resv_lockdep); +#endif + /** * dma_resv_init - initialize a reservation object * @obj: the reservation object |