Messages in this thread | | | From | Andy Lutomirski <> | Subject | [PATCH v3 0/7] mm, x86/vdso: Special IO mapping improvements | Date | Tue, 29 Dec 2015 20:12:17 -0800 |
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This applies on top of the earlier vdso pvclock series I sent out. Once that lands in -tip, this will apply to -tip.
This series cleans up the hack that is our vvar mapping. We currently initialize the vvar mapping as a special mapping vma backed by nothing whatsoever and then we abuse remap_pfn_range to populate it.
This cheats the mm core, probably breaks under various evil madvise workloads, and prevents handling faults in more interesting ways.
To clean it up, this series:
- Adds a special mapping .fault operation - Adds a vm_insert_pfn_prot helper - Uses the new .fault infrastructure in x86's vdso and vvar mappings - Hardens the HPET mapping, mitigating an HW attack surface that bothers me
Changes from v2: - Added patch 1, which is needed in -tip to fix the build - Fixed -EBUSY handling in vvar's .fault.
Changes from v1: - Lots of changelog clarification requested by akpm - Minor tweaks to style and comments in the first two patches
Andy Lutomirski (7): x86/vsdo: Fix build on PARAVIRT_CLOCK=y, KVM_GUEST=n mm: Add a vm_special_mapping .fault method mm: Add vm_insert_pfn_prot x86/vdso: Track each mm's loaded vdso image as well as its base x86,vdso: Use .fault for the vdso text mapping x86,vdso: Use .fault instead of remap_pfn_range for the vvar mapping x86/vdso: Disallow vvar access to vclock IO for never-used vclocks
arch/x86/entry/vdso/vdso2c.h | 7 -- arch/x86/entry/vdso/vma.c | 124 ++++++++++++++++++++------------ arch/x86/entry/vsyscall/vsyscall_gtod.c | 9 ++- arch/x86/include/asm/clocksource.h | 9 +-- arch/x86/include/asm/mmu.h | 3 +- arch/x86/include/asm/pvclock.h | 2 +- arch/x86/include/asm/vdso.h | 3 - arch/x86/include/asm/vgtod.h | 6 ++ include/linux/mm.h | 2 + include/linux/mm_types.h | 22 +++++- mm/memory.c | 25 ++++++- mm/mmap.c | 13 ++-- 12 files changed, 152 insertions(+), 73 deletions(-)
-- 2.5.0
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