Thanks, good explanation. > On Dec 13, 2021, at 1:47 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > On Mon, Dec 13, 2021 at 08:27:42PM +0000, Matthew Wilcox wrote: >> On Mon, Dec 13, 2021 at 07:18:57PM +0000, William Kucharski wrote: >>> I like these, but a quick question: >>> >>> Since the usercopy_abort() calls are all because the offset exceeds the page >>> size, is there a reason why you don't specifically state that via the detail >>> parameter rather than just supply a NULL pointer? >> >> Hmm ... I'd defer to Kees on this, because I'm not familiar with >> usercopy_abort() usage, but the only places which use the detail >> parameter today are slab/slub, which use it to pass the name of >> the slab. I think the user is supposed to infer that we overran the >> end of the page based on the offset & length values. > > I agree that leaving it NULL is best here. The "detail" is really about > adding more information about which thing it was, which for slab makes > sense, but most other stuff there isn't really anything to quickly > distinguish one from another (i.e. vmap is all vmap). > > -- > Kees Cook
