x86/entry: Call enter_from_user_mode() with IRQs off
authorAndy Lutomirski <luto@kernel.org>
Wed, 9 Mar 2016 21:24:33 +0000 (13:24 -0800)
committerIngo Molnar <mingo@kernel.org>
Thu, 10 Mar 2016 09:53:26 +0000 (10:53 +0100)
commit9999c8c01f34c918a57d6e5ba2f5d8b79aa04801
treefc47bd645a0dd3d20f8a1fd78812d9e6f09b5ad7
parenta798f091113ef4999277dbe0483d37d04fa35b2e
x86/entry: Call enter_from_user_mode() with IRQs off

Now that slow-path syscalls always enter C before enabling
interrupts, it's straightforward to call enter_from_user_mode() before
enabling interrupts rather than doing it as part of entry tracing.

With this change, we should finally be able to retire exception_enter().

This will also enable optimizations based on knowing that we never
change context tracking state with interrupts on.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/bc376ecf87921a495e874ff98139b1ca2f5c5dd7.1457558566.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/entry/common.c
arch/x86/include/asm/thread_info.h