Re: [PATCH] RDMA/core: Remove rcu attr for uverbs_api_ioctl_method.handler

Jason Gunthorpe
2022-10-25T16:00:11Z

On Tue, Oct 25, 2022 at 08:24:20AM -0700, Yonghong Song wrote:
> The current uverbs_api_ioctl_method definition:
> struct uverbs_api_ioctl_method {
> int(__rcu *handler)(struct uverbs_attr_bundle *attrs);
> DECLARE_BITMAP(attr_mandatory, UVERBS_API_ATTR_BKEY_LEN);
> ...
> };
> The struct member 'handler' is marked with __rcu. But unless
> the function body pointed by 'handler' is changing (e.g., jited)
> during runtime, there is no need with __rcu.

Huh? This is a sparse marker, it says that the pointer must always be
loaded with rcu_dereference

It has nothing to do with JIT, this patch is not correct

Jason