[RFC/PATCH 0/7] x86_32: Migrate to new entry/exit paths

From: Andy Lutomirski
Date: Wed Jul 08 2015 - 15:24:19 EST


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.

Al is cc'd, because some of this partially reverts some of his old
changes.

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

NB: Even if this code turns out to be perfect, patches 3 and 4 need
to be squashed together. Patch 3 is a hack to temporarily add an
assertion that the existing asm works the way I think it does. The
assertion doesn't apprear to fire but, again, I need to pound on it
harder.

Andy Lutomirski (7):
x86/entry/32: Remove 32-bit syscall audit optimizations
x86/entry/32: Fix an incorrect comment for work_notifysig_v86
[TEMPORARY] x86/entry/32: Sanity check for work_notifysig
x86/entry/32: Finish removing bogus kernel-mode check
x86/vm86: Teach handle_vm86_trap to return to 32bit mode directly
x86/entry/32: Use prepare_exit_to_usermode and syscall_return_slowpath
x86/entry: Remove do_notify_resume, syscall_trace_leave, and their TIF
masks

arch/x86/entry/common.c | 57 ----------------
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 | 16 -----
arch/x86/kernel/traps.c | 12 ++++
arch/x86/kernel/vm86_32.c | 8 +--
7 files changed, 26 insertions(+), 199 deletions(-)

--
2.4.3

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