From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755502AbbCMOJm (ORCPT ); Fri, 13 Mar 2015 10:09:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50478 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752816AbbCMOJl (ORCPT ); Fri, 13 Mar 2015 10:09:41 -0400 From: Denys Vlasenko To: Andy Lutomirski Cc: Denys Vlasenko , Linus Torvalds , Steven Rostedt , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Oleg Nesterov , Frederic Weisbecker , Alexei Starovoitov , Will Drewry , Kees Cook , x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] x86: simplify task_pt_regs() macro definition Date: Fri, 13 Mar 2015 15:09:03 +0100 Message-Id: <1426255743-5394-1-git-send-email-dvlasenk@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Before this change, task_pt_regs() was using KSTK_TOP(), and it was the only use of that macro. In turn, KSTK_TOP used THREAD_SIZE_LONGS, and it was the only use of that macro too. Fold these macros into task_pt_regs(). Tweak comment about "- 8" - we now use a symbolic constant, not literal 8. Signed-off-by: Denys Vlasenko CC: Linus Torvalds CC: Steven Rostedt CC: Ingo Molnar CC: Borislav Petkov CC: "H. Peter Anvin" CC: Andy Lutomirski CC: Oleg Nesterov CC: Frederic Weisbecker CC: Alexei Starovoitov CC: Will Drewry CC: Kees Cook CC: x86@kernel.org CC: linux-kernel@vger.kernel.org --- arch/x86/include/asm/processor.h | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 87474b2..d42c959 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -847,15 +847,8 @@ static inline void spin_lock_prefetch(const void *x) extern unsigned long thread_saved_pc(struct task_struct *tsk); -#define THREAD_SIZE_LONGS (THREAD_SIZE/sizeof(unsigned long)) -#define KSTK_TOP(info) \ -({ \ - unsigned long *__ptr = (unsigned long *)(info); \ - (unsigned long)(&__ptr[THREAD_SIZE_LONGS]); \ -}) - /* - * The below -8 is to reserve 8 bytes on top of the ring0 stack. + * TOP_OF_KERNEL_STACK_PADDING reserves 8 bytes on top of the ring0 stack. * This is necessary to guarantee that the entire "struct pt_regs" * is accessible even if the CPU haven't stored the SS/ESP registers * on the stack (interrupt gate does not save these registers @@ -864,12 +857,11 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk); * "struct pt_regs" is possible, but they may contain the * completely wrong values. */ -#define task_pt_regs(task) \ -({ \ - struct pt_regs *__regs__; \ - __regs__ = (struct pt_regs *)(KSTK_TOP(task_stack_page(task)) - \ - TOP_OF_KERNEL_STACK_PADDING); \ - __regs__ - 1; \ +#define task_pt_regs(task) \ +({ \ + unsigned long __ptr = (unsigned long)task_stack_page(task); \ + __ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING; \ + ((struct pt_regs *)__ptr) - 1; \ }) #define KSTK_ESP(task) (task_pt_regs(task)->sp) -- 1.8.1.4