From patchwork Tue Nov 27 12:41:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 10700363 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A2D6413BF for ; Tue, 27 Nov 2018 12:42:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 91A662B07B for ; Tue, 27 Nov 2018 12:42:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8EF7C2B085; Tue, 27 Nov 2018 12:42:41 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A817A2B087 for ; Tue, 27 Nov 2018 12:42:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=+hQRcR9j+Yn/eqw7ysOh+oZMEdfoTHyG96Z3S8LaHM0=; b=BNX1vJEJgRwyBLf1MXtS3hwN9z YkWZgAxi+3J82KWn1ALc7qXm89d68V9P3nn79JK98ELR13wFQhREfGKACBEEdkJMBs9Px4/nqayk1 n/CFZHaL5xlsxXZ+WCtIK0Xlaj5kl3HcNX8BkF6iFP+OZKPl5A0SaAO7Z8hXNi5+w6HvJTCnLTQx/ pAlCBxQhiyz3VYEb0S7wxNiHqrhvy5W44OEO2L9GOQwRjmDm1inPEox5P0SPYWnZkqsjGip+5TxHK FK5TbrdxBZCIWDwch2gT7FvZdFIJGgtiIlakqjBNKh/OPqnvJ7ZD+SAzvcvG/U/TxrlT7iDv8/XBw NaIcmfOg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gRchJ-0007TK-VW; Tue, 27 Nov 2018 12:42:37 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gRcgb-0006vb-LG for linux-arm-kernel@lists.infradead.org; Tue, 27 Nov 2018 12:41:56 +0000 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 598123624; Tue, 27 Nov 2018 04:41:41 -0800 (PST) Received: from edgewater-inn.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 2A6583F911; Tue, 27 Nov 2018 04:41:41 -0800 (PST) Received: by edgewater-inn.cambridge.arm.com (Postfix, from userid 1000) id E159B1AE0E29; Tue, 27 Nov 2018 12:41:58 +0000 (GMT) From: Will Deacon To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 3/3] arm64: entry: Remove confusing comment Date: Tue, 27 Nov 2018 12:41:57 +0000 Message-Id: <1543322517-470-4-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1543322517-470-1-git-send-email-will.deacon@arm.com> References: <1543322517-470-1-git-send-email-will.deacon@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181127_044153_728063_3CD690F5 X-CRM114-Status: GOOD ( 10.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: marc.zyngier@arm.com, catalin.marinas@arm.com, Will Deacon , suzuki.poulose@arm.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The comment about SYS_MEMBARRIER_SYNC_CORE relying on ERET being context-synchronizing is confusing and misplaced with kpti. Given that this is already documented under Documentation/ (see arch-support.txt for membarrier), remove the comment altogether. Signed-off-by: Will Deacon --- arch/arm64/kernel/entry.S | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index a7fc77ab4a0a..c7d050207e53 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -344,10 +344,6 @@ alternative_else_nop_endif ldp x28, x29, [sp, #16 * 14] ldr lr, [sp, #S_LR] add sp, sp, #S_FRAME_SIZE // restore sp - /* - * ARCH_HAS_MEMBARRIER_SYNC_CORE rely on eret context synchronization - * when returning from IPI handler, and when returning to user-space. - */ .if \el == 0 alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0