From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753388AbdK0Wgp (ORCPT ); Mon, 27 Nov 2017 17:36:45 -0500 Received: from bombadil.infradead.org ([65.50.211.133]:41739 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752228AbdK0Wft (ORCPT ); Mon, 27 Nov 2017 17:35:49 -0500 Message-Id: <20171127223405.329572992@infradead.org> User-Agent: quilt/0.63-1 Date: Mon, 27 Nov 2017 23:31:14 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org Cc: Dave Hansen , Andy Lutomirski , Ingo Molnar , Borislav Petkov , Brian Gerst , Denys Vlasenko , "H. Peter Anvin" , Josh Poimboeuf , Linus Torvalds , Peter Zijlstra , Rik van Riel , daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, linux-mm@kvack.org, michael.schwarz@iaik.tugraz.at, moritz.lipp@iaik.tugraz.at, richard.fellner@student.tugraz.at Subject: [PATCH 4/5] x86/mm/kaiser: Remove superfluous SWITCH_TO_KERNEL References: <20171127223110.479550152@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline; filename=peterz-kaiser-fixup-syscall-switch.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We never use this code-path with KAISER enabled. Fixes: ("Prepare the x86/entry assembly code for entry/exit CR3 switching") Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/entry/entry_64.S | 8 -------- 1 file changed, 8 deletions(-) --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -201,14 +201,6 @@ ENTRY(entry_SYSCALL_64) swapgs movq %rsp, PER_CPU_VAR(rsp_scratch) - - /* - * The kernel CR3 is needed to map the process stack, but we - * need a scratch register to be able to load CR3. %rsp is - * clobberable right now, so use it as a scratch register. - * %rsp will look crazy here for a couple instructions. - */ - SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp /* Construct struct pt_regs on stack */