From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2349C2B9F8 for ; Tue, 25 May 2021 18:35:56 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 904126140F for ; Tue, 25 May 2021 18:35:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 904126140F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=hvF7hFlR5ddvwkMJCGyLDmZSH1C3Ry/5w+lVb7nq5Qk=; b=yBW7B36f4+IcbA tvp3RiueEb0ULzPkcM2AVkf2xYYDZl1iNV600sYulCjBgdNaO+2khQHDDBfiCrXMMuncTbnO6+x/b GPk0Y5SpNgKygfTNgW0t4qmbnM/NYRkiwT2AMcjQbtWZ4GyHcudGvROBtsYo4TH/7o+Ph8wMmee5p YL/yIlOz6TVEQv0VyguBik6LULgK+eBJQhWUHhCkbqEhZciWkcPLtvU4+sQbN1FbRhmGhRbBvsEzz /7FtyVuNpxIsy534yYv6SOAwSb+/U7ld8eQe7DhafgsYIqefukVL3jS+liDXrG31NdZQL7YfI1/oY D096rKCWF1DvWVicis6Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1llbsc-007ILY-Kr; Tue, 25 May 2021 18:34:14 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1llbsE-007IBs-IW for linux-arm-kernel@lists.infradead.org; Tue, 25 May 2021 18:33:51 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 658E31692; Tue, 25 May 2021 11:33:48 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 5DB503F719; Tue, 25 May 2021 11:33:47 -0700 (PDT) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, james.morse@arm.com, joey.gouly@arm.com, mark.rutland@arm.com, maz@kernel.org, will@kernel.org Subject: [PATCH v3 02/20] arm64: entry: unmask IRQ+FIQ after EL0 handling Date: Tue, 25 May 2021 19:32:44 +0100 Message-Id: <20210525183302.56293-3-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20210525183302.56293-1-mark.rutland@arm.com> References: <20210525183302.56293-1-mark.rutland@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210525_113350_696605_A607BB64 X-CRM114-Status: GOOD ( 15.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org For non-fatal exceptions taken from EL0, we expect that at some point during exception handling it is possible to return to a regular process context with all exceptions unmasked (e.g. as we do in do_notify_resume()), and we generally aim to unmask exceptions wherever possible. While handling SError and debug exceptions from EL0, we need to leave some exceptions masked during handling. Handling SError requires us to mask SError (which also requires masking IRQ+FIQ), and handing debug exceptions requires us to mask debug (which also requires masking SError+IRQ+FIQ). Once do_serror() or do_debug_exception() has returned, we no longer need to mask exceptions, and can unmask them all, which is what we did prior to commit: 9034f6251572a474 ("arm64: Do not enable IRQs for ct_user_exit") ... where we had to mask IRQs as for context_tracking_user_exit() expected IRQs to be masked. Since then, we realised that our context tracking wasn't entirely correct, and reworked the entry code to fix this. As of commit: 23529049c6842382 ("arm64: entry: fix non-NMI user<->kernel transitions") ... we replaced the call to context_tracking_user_exit() with a call to user_exit_irqoff() as part of enter_from_user_mode(), which occurs earlier, before the we run the body of the handler and unmask exceptions in DAIF. When we return to userspace, we go via ret_to_user(), which masks exceptions in DAIF prior to calling user_enter_irqoff() as part of exit_to_user_mode(). Thus, there's no longer a reason to leave IRQs or FIQs masked at the end of the EL) debug or error handlers, as neither the user exit context tracking nor the user entry context tracking requires this. Let's bring these into line with other EL0 exceptions handlers and ensure that IRQ and FIQ are unmasked in DAIF at some point during the handler. Signed-off-by: Mark Rutland Reviewed-by: Joey Gouly Cc: Catalin Marinas Cc: James Morse Cc: Marc Zyngier Cc: Will Deacon --- arch/arm64/kernel/entry-common.c | 2 +- arch/arm64/kernel/entry.S | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 340d04e13617..02be1517e08f 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -398,7 +398,7 @@ static void noinstr el0_dbg(struct pt_regs *regs, unsigned long esr) enter_from_user_mode(); do_debug_exception(far, esr, regs); - local_daif_restore(DAIF_PROCCTX_NOIRQ); + local_daif_restore(DAIF_PROCCTX); } static void noinstr el0_svc(struct pt_regs *regs) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 3513984a88bd..6b2f6f5c5bb8 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -794,7 +794,7 @@ el0_error_naked: mov x0, sp mov x1, x25 bl do_serror - enable_da + enable_daif b ret_to_user SYM_CODE_END(el0_error) -- 2.11.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel