From patchwork Fri May 25 09:49:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10426835 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 C86AD6025B for ; Fri, 25 May 2018 09:54:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C000029639 for ; Fri, 25 May 2018 09:54:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B424B2963C; Fri, 25 May 2018 09:54:44 +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=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI 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 E752E2963B for ; Fri, 25 May 2018 09:54:43 +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=UsXKPS5AxlWhLIuBNPARVfYzT9HfRsBTTTwrhKNoYAA=; b=HGyCvccI09tpuAERnqZj/N6CFA IJcFs3NHnKtvonz51Q6r+238UFo8WdGmrUkn01z8QUICv/OV235sQ8CEUaVLzxFiquWdrPku+CpRR jK4GWDxWd3oQB23yuEhQcXnFlt7OydgWr0p0E34JbQETaCf/cCxgeC8yledt3JVxPbLEEX3up+oO0 muYZTvLfXfANvymORKIX97Cj27fQRSgw/NZgurbdBAQ8LXlk17MMmGs4Of6EZVDoJNPjseoIOHTr0 ZMG3JLVYIzKvfVOvP0+eHtanKN94wWAGZZ5JXbeik1LVSEemwEQQ3F8dHK8FdKpcvX8wwcSEcv3DF ccHC9gwQ==; 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 1fM9Qa-000255-E3; Fri, 25 May 2018 09:54:28 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fM9Mf-0007MC-Qw for linux-arm-kernel@lists.infradead.org; Fri, 25 May 2018 09:50:42 +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 2A417174E; Fri, 25 May 2018 02:50:20 -0700 (PDT) Received: from e112298-lin.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 205C13F25D; Fri, 25 May 2018 02:50:17 -0700 (PDT) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 10/26] arm64: Delay daif masking for user return Date: Fri, 25 May 2018 10:49:16 +0100 Message-Id: <1527241772-48007-11-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1527241772-48007-1-git-send-email-julien.thierry@arm.com> References: <1527241772-48007-1-git-send-email-julien.thierry@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180525_025026_018557_64A06F5D X-CRM114-Status: GOOD ( 10.24 ) 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: mark.rutland@arm.com, daniel.thompson@linaro.org, Julien Thierry , marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, christoffer.dall@arm.com, james.morse@arm.com, joel@joelfernandes.org 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 Masking daif flags is done very early before returning to EL0. Only toggle the interrupt masking while in the vector entry and mask daif once in kernel_exit. Signed-off-by: Julien Thierry Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: James Morse --- arch/arm64/kernel/entry.S | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index ec2ee72..20252d5 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -240,9 +240,9 @@ alternative_else_nop_endif .endm .macro kernel_exit, el - .if \el != 0 disable_daif + .if \el != 0 /* Restore the task's original addr_limit. */ ldr x20, [sp, #S_ORIG_ADDR_LIMIT] str x20, [tsk, #TSK_TI_ADDR_LIMIT] @@ -872,7 +872,7 @@ ENDPROC(el0_error) * and this includes saving x0 back into the kernel stack. */ ret_fast_syscall: - disable_daif + disable_irq // disable interrupts str x0, [sp, #S_X0] // returned x0 ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing and x2, x1, #_TIF_SYSCALL_WORK @@ -882,7 +882,7 @@ ret_fast_syscall: enable_step_tsk x1, x2 kernel_exit 0 ret_fast_syscall_trace: - enable_daif + enable_irq // enable interrupts b __sys_trace_return_skipped // we already saved x0 /* @@ -900,7 +900,7 @@ work_pending: * "slow" syscall return path. */ ret_to_user: - disable_daif + disable_irq // disable interrupts ldr x1, [tsk, #TSK_TI_FLAGS] and x2, x1, #_TIF_WORK_MASK cbnz x2, work_pending