diff options
| author | Mark Zhang <markzhang@nvidia.com> | 2021-06-03 16:18:03 +0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2021-06-03 14:19:53 -0300 |
| commit | a0ffb4c12f7fa89163e228e6f27df09b46631db1 (patch) | |
| tree | 6b491664cf556a62801f3d0f18a3cae8e6fc27d2 /drivers/infiniband | |
| parent | a3e74fb9247cd530dca246699d5eb5a691884d32 (diff) | |
| download | linux-a0ffb4c12f7fa89163e228e6f27df09b46631db1.tar.bz2 | |
RDMA/mlx5: Use different doorbell memory for different processes
In a fork scenario, the parent and child can have same virtual address and
also share the uverbs fd. That causes to the list_for_each_entry search
return same doorbell physical page for all processes, even though that
page has been COW' or copied.
This patch takes the mm_struct into consideration during search, to make
sure that VA's belonging to different processes are not intermixed.
Resolves the malfunction of uverbs after fork in some specific cases.
Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Link: https://lore.kernel.org/r/feacc23fe0bc6e1088c6824d5583798745e72405.1622726212.git.leonro@nvidia.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/mlx5/doorbell.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/mlx5/doorbell.c b/drivers/infiniband/hw/mlx5/doorbell.c index 61475b571531..7af4df7a6823 100644 --- a/drivers/infiniband/hw/mlx5/doorbell.c +++ b/drivers/infiniband/hw/mlx5/doorbell.c @@ -41,6 +41,7 @@ struct mlx5_ib_user_db_page { struct ib_umem *umem; unsigned long user_virt; int refcnt; + struct mm_struct *mm; }; int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, @@ -53,7 +54,8 @@ int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, mutex_lock(&context->db_page_mutex); list_for_each_entry(page, &context->db_page_list, list) - if (page->user_virt == (virt & PAGE_MASK)) + if ((current->mm == page->mm) && + (page->user_virt == (virt & PAGE_MASK))) goto found; page = kmalloc(sizeof(*page), GFP_KERNEL); @@ -71,6 +73,8 @@ int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, kfree(page); goto out; } + mmgrab(current->mm); + page->mm = current->mm; list_add(&page->list, &context->db_page_list); @@ -91,6 +95,7 @@ void mlx5_ib_db_unmap_user(struct mlx5_ib_ucontext *context, struct mlx5_db *db) if (!--db->u.user_page->refcnt) { list_del(&db->u.user_page->list); + mmdrop(db->u.user_page->mm); ib_umem_release(db->u.user_page->umem); kfree(db->u.user_page); } |