From: Jason Gunthorpe jgg@mellanox.com
commit c485b19d52c4ba269dfd027945dee81755fdd530 upstream.
The commit below moved all of the destruction to the disassociate step and cleaned up the event channel during destroy_uobj.
However, when ib_uverbs_free_hw_resources() pushes IB_EVENT_DEVICE_FATAL and then immediately goes to destroy all uobjects this causes ib_uverbs_free_event_queue() to discard the queued event if userspace hasn't already read() it.
Unlike all other event queues async FD needs to defer the ib_uverbs_free_event_queue() until FD release. This still unregisters the handler from the IB device during disassociation.
Fixes: 3e032c0e92aa ("RDMA/core: Make ib_uverbs_async_event_file into a uobject") Link: https://lore.kernel.org/r/20200507063348.98713-2-leon@kernel.org Signed-off-by: Yishai Hadas yishaih@mellanox.com Signed-off-by: Leon Romanovsky leonro@mellanox.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/core/rdma_core.c | 3 ++- drivers/infiniband/core/uverbs.h | 1 + drivers/infiniband/core/uverbs_main.c | 2 +- .../core/uverbs_std_types_async_fd.c | 26 ++++++++++++++++++- 4 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c index 177333d8bcda..bf8e149d3191 100644 --- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -459,7 +459,8 @@ alloc_begin_fd_uobject(const struct uverbs_api_object *obj, struct ib_uobject *uobj; struct file *filp;
- if (WARN_ON(fd_type->fops->release != &uverbs_uobject_fd_release)) + if (WARN_ON(fd_type->fops->release != &uverbs_uobject_fd_release && + fd_type->fops->release != &uverbs_async_event_release)) return ERR_PTR(-EINVAL);
new_fd = get_unused_fd_flags(O_CLOEXEC); diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h index 7df71983212d..2673cb1cd655 100644 --- a/drivers/infiniband/core/uverbs.h +++ b/drivers/infiniband/core/uverbs.h @@ -219,6 +219,7 @@ void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue); void ib_uverbs_init_async_event_file(struct ib_uverbs_async_event_file *ev_file); void ib_uverbs_free_event_queue(struct ib_uverbs_event_queue *event_queue); void ib_uverbs_flow_resources_free(struct ib_uflow_resources *uflow_res); +int uverbs_async_event_release(struct inode *inode, struct file *filp);
int ib_alloc_ucontext(struct uverbs_attr_bundle *attrs); int ib_init_ucontext(struct uverbs_attr_bundle *attrs); diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index 17fc25db0311..cb5b59123d8f 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -346,7 +346,7 @@ const struct file_operations uverbs_async_event_fops = { .owner = THIS_MODULE, .read = ib_uverbs_async_event_read, .poll = ib_uverbs_async_event_poll, - .release = uverbs_uobject_fd_release, + .release = uverbs_async_event_release, .fasync = ib_uverbs_async_event_fasync, .llseek = no_llseek, }; diff --git a/drivers/infiniband/core/uverbs_std_types_async_fd.c b/drivers/infiniband/core/uverbs_std_types_async_fd.c index 82ec0806b34b..462deb506b16 100644 --- a/drivers/infiniband/core/uverbs_std_types_async_fd.c +++ b/drivers/infiniband/core/uverbs_std_types_async_fd.c @@ -26,10 +26,34 @@ static int uverbs_async_event_destroy_uobj(struct ib_uobject *uobj, container_of(uobj, struct ib_uverbs_async_event_file, uobj);
ib_unregister_event_handler(&event_file->event_handler); - ib_uverbs_free_event_queue(&event_file->ev_queue); return 0; }
+int uverbs_async_event_release(struct inode *inode, struct file *filp) +{ + struct ib_uverbs_async_event_file *event_file; + struct ib_uobject *uobj = filp->private_data; + int ret; + + if (!uobj) + return uverbs_uobject_fd_release(inode, filp); + + event_file = + container_of(uobj, struct ib_uverbs_async_event_file, uobj); + + /* + * The async event FD has to deliver IB_EVENT_DEVICE_FATAL even after + * disassociation, so cleaning the event list must only happen after + * release. The user knows it has reached the end of the event stream + * when it sees IB_EVENT_DEVICE_FATAL. + */ + uverbs_uobject_get(uobj); + ret = uverbs_uobject_fd_release(inode, filp); + ib_uverbs_free_event_queue(&event_file->ev_queue); + uverbs_uobject_put(uobj); + return ret; +} + DECLARE_UVERBS_NAMED_METHOD( UVERBS_METHOD_ASYNC_EVENT_ALLOC, UVERBS_ATTR_FD(UVERBS_ATTR_ASYNC_EVENT_ALLOC_FD_HANDLE,