On Wed, May 27, 2020 at 06:36:18PM -0700, Sean Christopherson wrote: > On Thu, May 28, 2020 at 04:23:19AM +0300, Jarkko Sakkinen wrote: > > On Wed, May 27, 2020 at 10:46:38PM +0200, Borislav Petkov wrote: > > > On Tue, May 26, 2020 at 09:21:11PM -0700, Sean Christopherson wrote: > > > > In other words, sgx_alloc_epc_section() is poorly named. It doesn't > > > > actually allocate EPC, it allocates kernel structures to map and track EPC. > > > > sgx_(un)map_epc_section() would be more accurate and would hopefully > > > > alleviate some of the confusion. > > ... > > > I'm not sure I follow fully Sean's reasoning but the way alloc is used > > mostly in Linux is to ask through some API the used kernel memory > > allocator to give memory for some kernel data structures. > > Function names are usually some form of > > <namespace>_<verb>_<object> > > where 'object' is the target of the 'verb'. So sgx_alloc_epc_section() > is most likely going to be read as "SGX, allocate an EPC section". But > that code doesn't allocate an EPC section, it maps an EPC section, and on > success, adds the section's pages to the unsanitized list, i.e. what > effectively becomes the pool of EPC pages. The allocation part is a side > effect of how we track EPC pages, it's not the primary purpose of the > function. > > Maybe sgx_add_epc_section() and sgx_remove_epc_section() would be better > than map/unmap? > > Eliminating the misnamed sgx_alloc_epc_section() frees up the "alloc" verb > for use in the actual EPC page allocation paths, i.e. avoids having to > rename those to "grab". IMO, "alloc" is the best name as it most closely > aligns with the nomenclature for regular pages, e.g. "grab" is most often > used to elevate refcounts. I'm thinking that you are over-engineering something this :-) Naming is never perfect. But I do get the original comment about sgx_alloc_page(). /Jarkko
