On Thu, May 30, 2019 at 7:15 PM Catalin Marinas <catalin.mari...@arm.com> wrote: > > On Tue, May 28, 2019 at 04:14:45PM +0200, Andrey Konovalov wrote: > > Thanks for a lot of valuable input! I've read through all the replies > > and got somewhat lost. What are the changes I need to do to this > > series? > > > > 1. Should I move untagging for memory syscalls back to the generic > > code so other arches would make use of it as well, or should I keep > > the arm64 specific memory syscalls wrappers and address the comments > > on that patch? > > Keep them generic again but make sure we get agreement with Khalid on > the actual ABI implications for sparc.
OK, will do. I find it hard to understand what the ABI implications are. I'll post the next version without untagging in brk, mmap, munmap, mremap (for new_address), mmap_pgoff, remap_file_pages, shmat and shmdt. > > > 2. Should I make untagging opt-in and controlled by a command line argument? > > Opt-in, yes, but per task rather than kernel command line option. > prctl() is a possibility of opting in. OK. Should I store a flag somewhere in task_struct? Should it be inheritable on clone? > > > 3. Should I "add Documentation/core-api/user-addresses.rst to describe > > proper care and handling of user space pointers with untagged_addr(), > > with examples based on all the cases seen so far in this series"? > > Which examples specifically should it cover? > > I think we can leave 3 for now as not too urgent. What I'd like is for > Vincenzo's TBI user ABI document to go into a more common place since we > can expand it to cover both sparc and arm64. We'd need an arm64-specific > doc as well for things like prctl() and later MTE that sparc may support > differently. OK. > > -- > Catalin
