Collected vdso/vsyscall fixes for 3.1

This fixes various problems that cropped up with the vdso patches.

- Patch 1 fixes an information leak to userspace.
- Patches 2 and 3 fix the kernel build on gold.
- Patches 4 and 5 fix Xen (I hope).

Konrad, could you could test these on Xen and run 'test_vsyscall test' [1]? I don't have a usable Xen setup.

Also, I'd appreciate a review of patches 4 and 5 from some Xen/paravirt people.

[1] https://gitorious.org/linux-test-utils/linux-clock-tests

Andy Lutomirski (5):
x86-64: Pad vDSO to a page boundary
x86-64: Move the "user" vsyscall segment out of the data segment.
x86-64: Work around gold bug 13023
x86-64/xen: Enable the vvar mapping
x86-64: Add user_64bit_mode paravirt op

 arch/x86/include/asm/desc.h           |    4 +-
 arch/x86/include/asm/paravirt_types.h |    6 ++++
 arch/x86/include/asm/ptrace.h         |   19 +++++++++++++
 arch/x86/kernel/paravirt.c            |    4 +++
 arch/x86/kernel/step.c                |    2 +-
 arch/x86/kernel/vmlinux.lds.S         |   46 ++++++++++++++++++---------------
 arch/x86/kernel/vsyscall_64.c         |    6 +---
 arch/x86/mm/fault.c                   |    2 +-
 arch/x86/vdso/vdso.S                  |    1 +
 arch/x86/xen/enlighten.c              |    1 +
 arch/x86/xen/mmu.c                    |    4 ++-
 11 files changed, 64 insertions(+), 31 deletions(-)

1.7.6