x86_32: Migrate to new entry/exit paths

This is a review version of the 32-bit asm-to-C migration. I think it works, but it's not yet well enough tested. I'm a lot more familiar with the 64-bit asm than the 32-bit asm.

The vm86 stuff especially needs much more careful testing. Brian, since you're playing with vm86 now, can you take a look?

Changes from v1:
- Fix some nasty vm86 issues. v1 was a regression. v2 is an improvement over the status quo AFAICT.
- Add patch 1, which is probably worthwhile on its own.
- Get rid of the temporary ud2 hack.

Andy Lutomirski (6):
x86/selftests, x86/vm86: Improve entry_from_vm86 selftest x86/entry/32: Remove 32-bit syscall audit optimizations x86/entry/32: Fix an incorrect comment for work_notifysig_v86 x86/entry/32: Remove unnecessary asm check for returns to kernel mode x86/entry/32: Migrate to C exit path and rework vm86 exit hack x86/entry: Remove do_notify_resume, syscall_trace_leave, and their TIF
masks

 arch/x86/entry/common.c                       | 107 ++++++++++-----------
 arch/x86/entry/entry_32.S                     | 130 +++----------------------
 arch/x86/include/asm/ptrace.h                 |   1 -
 arch/x86/include/asm/signal.h                 |   1 -
 arch/x86/include/asm/thread_info.h            |  18 +---
 arch/x86/kernel/vm86_32.c                     |   6 +-
 tools/testing/selftests/x86/entry_from_vm86.c | 132 ++++++++++++++++++++++++--
 7 files changed, 191 insertions(+), 204 deletions(-)

2.4.3