lkml.org 
[lkml]   [2016]   [Jan]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v3 0/7] mm, x86/vdso: Special IO mapping improvements
From
On Tue, Dec 29, 2015 at 8:12 PM, Andy Lutomirski <luto@kernel.org> wrote:
> 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(-)

Reviewed-by: Kees Cook <keescook@chromium.org>

I think this makes things much more readable. :)

-Kees

--
Kees Cook
Chrome OS & Brillo Security


\
 
 \ /
  Last update: 2016-01-05 01:21    [W:0.102 / U:0.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site