On 2/26/19 9:18 AM, Andrey Konovalov wrote: >> This seems like something >> where we would ideally add an __tagged annotation (or something) to the >> source tree and then have sparse rules that can look for missed untags. > This has been suggested before, search for __untagged here [1]. > However there are many places in the kernel where a __user pointer is > casted into unsigned long and passed further. I'm not sure if it's > possible apply a __tagged/__untagged kind of attribute to non-pointer > types, is it? > > [1] https://patchwork.kernel.org/patch/10581535/ I believe we have sparse checking __GFP_* flags. We also have a gfp_t for them and I'm unsure whether the sparse support is tied to _that_ or whether it's just by tagging the type itself as being part of a discrete address space.