Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758127AbdLVJja (ORCPT ); Fri, 22 Dec 2017 04:39:30 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:38956 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965097AbdLVJCT (ORCPT ); Fri, 22 Dec 2017 04:02:19 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Lutomirski , Borislav Petkov , Borislav Petkov , Brian Gerst , Dave Hansen , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ingo Molnar Subject: [PATCH 4.14 051/159] x86/entry/64: Remove all remaining direct thread_struct::sp0 reads Date: Fri, 22 Dec 2017 09:45:36 +0100 Message-Id: <20171222084626.526262699@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171222084623.668990192@linuxfoundation.org> References: <20171222084623.668990192@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2800 Lines: 87 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski commit 46f5a10a721ce8dce8cc8fe55279b49e1c6b3288 upstream. The only remaining readers in context switch code or vm86(), and they all just want to update TSS.sp0 to match the current task. Replace them all with a new helper update_sp0(). Signed-off-by: Andy Lutomirski Reviewed-by: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/2d231687f4ff288c9d9e98d7861b7df374246ac3.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/switch_to.h | 6 ++++++ arch/x86/kernel/process_32.c | 2 +- arch/x86/kernel/process_64.c | 2 +- arch/x86/kernel/vm86_32.c | 4 ++-- 4 files changed, 10 insertions(+), 4 deletions(-) --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -85,4 +85,10 @@ static inline void refresh_sysenter_cs(s } #endif +/* This is used when switching tasks or entering/exiting vm86 mode. */ +static inline void update_sp0(struct task_struct *task) +{ + load_sp0(task->thread.sp0); +} + #endif /* _ASM_X86_SWITCH_TO_H */ --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -287,7 +287,7 @@ __switch_to(struct task_struct *prev_p, * current_thread_info(). Refresh the SYSENTER configuration in * case prev or next is vm86. */ - load_sp0(next->sp0); + update_sp0(next_p); refresh_sysenter_cs(next); this_cpu_write(cpu_current_top_of_stack, (unsigned long)task_stack_page(next_p) + --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -465,7 +465,7 @@ __switch_to(struct task_struct *prev_p, this_cpu_write(current_task, next_p); /* Reload sp0. */ - load_sp0(next->sp0); + update_sp0(next_p); /* * Now maybe reload the debug registers and handle I/O bitmaps --- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -149,7 +149,7 @@ void save_v86_state(struct kernel_vm86_r preempt_disable(); tsk->thread.sp0 = vm86->saved_sp0; tsk->thread.sysenter_cs = __KERNEL_CS; - load_sp0(tsk->thread.sp0); + update_sp0(tsk); refresh_sysenter_cs(&tsk->thread); vm86->saved_sp0 = 0; preempt_enable(); @@ -374,7 +374,7 @@ static long do_sys_vm86(struct vm86plus_ refresh_sysenter_cs(&tsk->thread); } - load_sp0(tsk->thread.sp0); + update_sp0(tsk); preempt_enable(); if (vm86->flags & VM86_SCREEN_BITMAP)