On 9/28/21 10:12 AM, Christoph Hellwig wrote: > On Tue, Sep 28, 2021 at 08:24:43AM +0530, Anshuman Khandual wrote: >>> simple switch statement provided by each architecture. See the below >>> WIP which just works for x86 and without pagetable debugging for where I >>> think we should be going. >> >> Sure, this will work as well but all platforms need to be changed at once. >> Is there any platform that would not subscribe ARCH_HAS_GET_PAGE_PROT and >> export its own vm_get_page_prot() ? AFAICS all platforms are required to >> export __PXXX and __SXXX elements currently. >> >> This seems to be a better idea than the current proposal. Probably all the >> vm_flags combinations, which will be used in those switch statements can be >> converted into macros just to improve readability. Are you planning to send >> this as a proper patch soon ? > > This was just a quіck WIP patch. If you have some spare time to tackle > it for real I'd sugget the following approach: Sure, will try and get this working. > > 1) Remove the direct references to protection_map in debug_vm_pgtable.c > 2) add the ARCH_HAS_GET_PAGE_PROT symbol that lets architectures > provide vm_get_page_prot itself and not define protection_map at all > in this case > 3) convert all architectures that touch protection_map to provide > vm_get_page_prot themselves > 4) mark protection_map static > 5) convert all architectures that provide arch_filter_pgprot and/or > arch_vm_get_page_prot to provide vm_get_page_prot directly and > remove those hooks > 6) remove the __S???/__P??? macros and the generic vm_get_page_prot > after providing an arch implementation for every architecture. > This can maybe simplified with a new generic version that directly > looks at PAGE_* macros, but that will need further investigation > first. >
