diff options
| author | Jason Gunthorpe <jgg@mellanox.com> | 2018-02-13 11:18:36 +0100 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2018-02-15 22:59:46 +0100 |
| commit | d9dc7a3500a58de9bf3861d1a96ffeab42624b4f (patch) | |
| tree | 65f2a21bdbfc8171e89f8e656d1a8c0d416702de /drivers/infiniband | |
| parent | IB/uverbs: Fix possible oops with duplicate ioctl attributes (diff) | |
| download | linux-d9dc7a3500a58de9bf3861d1a96ffeab42624b4f.tar.xz linux-d9dc7a3500a58de9bf3861d1a96ffeab42624b4f.zip | |
IB/uverbs: Hold the uobj write lock after allocate
This clarifies the design intention that time between allocate and
commit has the uobj exclusive to the caller. We already guarantee
this by delaying publishing the uobj pointer via idr_insert,
fd_install, list_add, etc.
Additionally holding the usecnt lock during this period provides
extra clarity and more protection against future mistakes.
Fixes: 3832125624b7 ("IB/core: Add support for idr types")
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/core/rdma_core.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c index 85b5ee4defa4..3fe6035abde6 100644 --- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -141,7 +141,12 @@ static struct ib_uobject *alloc_uobj(struct ib_ucontext *context, */ uobj->context = context; uobj->type = type; - atomic_set(&uobj->usecnt, 0); + /* + * Allocated objects start out as write locked to deny any other + * syscalls from accessing them until they are committed. See + * rdma_alloc_commit_uobject + */ + atomic_set(&uobj->usecnt, -1); kref_init(&uobj->ref); return uobj; @@ -527,6 +532,10 @@ int rdma_alloc_commit_uobject(struct ib_uobject *uobj) return ret; } + /* matches atomic_set(-1) in alloc_uobj */ + lockdep_check(uobj, true); + atomic_set(&uobj->usecnt, 0); + uobj->type->type_class->alloc_commit(uobj); up_read(&uobj->context->cleanup_rwsem); |