From patchwork Wed Jul 11 13:56:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 10519861 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AA180601D4 for ; Wed, 11 Jul 2018 13:58:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9E45F29103 for ; Wed, 11 Jul 2018 13:58:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 91715290FD; Wed, 11 Jul 2018 13:58:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3E80C290FD for ; Wed, 11 Jul 2018 13:58:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388332AbeGKOCL (ORCPT ); Wed, 11 Jul 2018 10:02:11 -0400 Received: from foss.arm.com ([217.140.101.70]:36408 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388287AbeGKOCL (ORCPT ); Wed, 11 Jul 2018 10:02:11 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 057B51BC0; Wed, 11 Jul 2018 06:57:44 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E00783F5B1; Wed, 11 Jul 2018 06:57:41 -0700 (PDT) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will.deacon@arm.com Cc: catalin.marinas@arm.com, dave.martin@arm.com, hch@infradead.org, james.morse@arm.com, linux@dominikbrodowski.net, linux-fsdevel@vger.kernel.org, marc.zyngier@arm.com, mark.rutland@arm.com, viro@zeniv.linux.org.uk Subject: [PATCHv5 11/21] arm64: don't restore GPRs when context tracking Date: Wed, 11 Jul 2018 14:56:46 +0100 Message-Id: <20180711135656.20670-12-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180711135656.20670-1-mark.rutland@arm.com> References: <20180711135656.20670-1-mark.rutland@arm.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Now that syscalls are invoked with pt_regs, we no longer need to ensure that the argument regsiters are live in the entry assembly, and it's fine to not restore them after context_tracking_user_exit() has corrupted them. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Cc: Will Deacon --- arch/arm64/kernel/entry.S | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 156c4e3fd1a4..c41b84d06644 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -41,19 +41,9 @@ * Context tracking subsystem. Used to instrument transitions * between user and kernel mode. */ - .macro ct_user_exit, syscall = 0 + .macro ct_user_exit #ifdef CONFIG_CONTEXT_TRACKING bl context_tracking_user_exit - .if \syscall == 1 - /* - * Save/restore needed during syscalls. Restore syscall arguments from - * the values already saved on stack during kernel_entry. - */ - ldp x0, x1, [sp] - ldp x2, x3, [sp, #S_X2] - ldp x4, x5, [sp, #S_X4] - ldp x6, x7, [sp, #S_X6] - .endif #endif .endm