x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()
authorAndy Lutomirski <luto@amacapital.net>
Fri, 6 Mar 2015 03:19:03 +0000 (19:19 -0800)
committerIngo Molnar <mingo@kernel.org>
Fri, 6 Mar 2015 07:32:57 +0000 (08:32 +0100)
commit75182b1632a89f12540baa1806a7c5c180db620c
tree1e3f5d0c4a34c4ca2de42c25657f395ab6ad6e76
parent8ef46a672a7d852709561d10672b6eaa8a4acd82
x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()

This will make modifying the semantics of kernel_stack easier.

The change to ist_begin_non_atomic() is necessary because sp0 no
longer points to the same THREAD_SIZE-aligned region as RSP;
it's one byte too high for that.  At Denys' suggestion, rather
than offsetting it, just check explicitly that we're in the
correct range ending at sp0.  This has the added benefit that we
no longer assume that the thread stack is aligned to
THREAD_SIZE.

Suggested-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ef8254ad414cbb8034c9a56396eeb24f5dd5b0de.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/include/asm/thread_info.h
arch/x86/kernel/traps.c