I'm getting reasonably happy with this. It still needs more testing, but I want to get it out there.
The main things that need testing are the 5-level case for the both vsyscalls and the LDT. I'm getting a double-fault in ldt_gdt_64, but I haven't checked whether it's a bug in this series, and it kind of looks like it isn't. I'll figure it out in the morning. The docs also want updating for the 5 level case. Changes from v1: - vsyscalls actually work. - Added the "Warn and fail" patch to prevent the testing goof I had on v1. - Lots of cleanups Andy Lutomirski (6): x86/pti: Vastly simplify pgd synchronization Revert "x86/mm/pti: Disable native VSYSCALL" x86/vsyscall/64: Explicitly set _PAGE_USER in the pagetable hierarchy x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode x86/pti: Map the vsyscall page if needed x86/pti: Put the LDT in its own PGD if PTI is on Documentation/x86/x86_64/mm.txt | 11 ++- arch/x86/Kconfig | 8 -- arch/x86/entry/vsyscall/vsyscall_64.c | 37 ++++++++- arch/x86/include/asm/mmu_context.h | 33 +++++++- arch/x86/include/asm/pgtable.h | 6 +- arch/x86/include/asm/pgtable_64.h | 77 ++++++++---------- arch/x86/include/asm/pgtable_64_types.h | 2 + arch/x86/include/asm/processor.h | 23 ++++-- arch/x86/include/asm/vsyscall.h | 1 + arch/x86/kernel/ldt.c | 138 +++++++++++++++++++++++++++++--- arch/x86/mm/pti.c | 115 ++++++++++++++++---------- 11 files changed, 331 insertions(+), 120 deletions(-) -- 2.13.6
