On 16/02/2024 19:54, John Hubbard wrote: > On 2/16/24 08:56, Catalin Marinas wrote: > ... >>> The problem is that the contpte_* symbols are called from the ptep_* inline >>> functions. So where those inlines are called from modules, we need to make sure >>> the contpte_* symbols are available. >>> >>> John Hubbard originally reported this problem against v1 and I enumerated all >>> the drivers that call into the ptep_* inlines here: >>> https://lore.kernel.org/linux-arm-kernel/b994ff89-1a1f-26ca-9479-b08c77f94be8@xxxxxxx/#t >>> >>> So they definitely need to be exported. Perhaps we can tighten it to > > Yes. Let's keep the in-tree modules working. > >>> EXPORT_SYMBOL_GPL(), but I was being cautious as I didn't want to break anything >>> out-of-tree. I'm not sure what the normal policy is? arm64 seems to use ~equal >>> amounts of both. > > EXPORT_SYMBOL_GPL() seems appropriate and low risk. As Catalin says below, > these really are deeply core mm routines, and any module operating at this > level is not going to be able to survive on EXPORT_SYMBOL alone, IMHO. > > Now, if only I could find an out of tree module to test that claim on... :) > > >> I don't think we are consistent here. For example set_pte_at() can't be >> called from non-GPL modules because of __sync_icache_dcache. OTOH, such >> driver is probably doing something dodgy. Same with >> apply_to_page_range(), it's GPL-only (called from i915). >> >> Let's see if others have any view over the next week or so, otherwise >> I'd go for _GPL and relax it later if someone has a good use-case (can >> be a patch on top adding _GPL). > > I think going directly to _GPL for these is fine, actually. OK I'll send out a patch to convert these to _GPL on my return on Monday. Hopefully Andrew will be able to squash the patch into the existing series. > > > thanks,
