From patchwork Mon Jul 31 10:40:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pratyush Anand X-Patchwork-Id: 9871571 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 07CA9602F0 for ; Mon, 31 Jul 2017 10:42:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EE26828572 for ; Mon, 31 Jul 2017 10:42:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E32992858E; Mon, 31 Jul 2017 10:42:52 +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=-1.4 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM autolearn=no version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7681728572 for ; Mon, 31 Jul 2017 10:42:52 +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=D8vtbdEonf6R+UnBGVwzc5luweXehE4g1IbSLVF2sX4=; b=CuWtd9yQsHDwU6NAousqxjdtxi G2BBPpDsfmiLiyc+FcbZF7oYyPvr1FyvItJzrbzx4TAYlU1IkPyc3p+78rnMCy+jPk9+dE1NT4mfq 2tdC2KnomHBG0IE8uJ/TBAEdWJX7wS4oweSVT/sTCIUzZQ42rrIWDcwp6zejR6+apOmTlu90PxaYx A3m5flw3ErCOK+PZHEKPQr+3SaL9qUmbfqAnCLaQG8LXjBPofutOCqLFi7TfJyFsYhK2apZkVQ/tx Q0TN18K9MMi82DcrNoO5+mlKy2mYppPDTMBj7ppUqsL3Fy0yii4NZdwgyk12+uz0JMG7MjsNo7dx1 wqsV1q2A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dc89w-00069F-AR; Mon, 31 Jul 2017 10:42:48 +0000 Received: from mail-pg0-f49.google.com ([74.125.83.49]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dc88t-0004ji-9T for linux-arm-kernel@lists.infradead.org; Mon, 31 Jul 2017 10:41:48 +0000 Received: by mail-pg0-f49.google.com with SMTP id v189so7349900pgd.2 for ; Mon, 31 Jul 2017 03:41:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=vUnnDeM7OScf4FWUdOdd54zbP29Je0cAvW9etCWgGKY=; b=DoYrVEYkARpj8YyoXt0sp5VZn5l8SOY1rADvIr/TptHAkE/Rm9ud1wYxs3C+dRv/1Y 5M3XzbX4AyQlrzceLIGmsfW8Mrx2OZgdaXeYtqsguPDMfPVWhG80ld3hRQd96b8g6LPv leB1vNOIuPha+ZDSii//omGVugU5uy0WzxFCZPeIcrHjvWOiOOO2c465msNqO+CyzZe6 fAvrVBJg1/OigLGShAg6mvu+gcgES+mQDve7qfof1nV1pZj4l/XBe7NHA7Q6Qy5/CR4q rTDd5Z7cx6DKc1oJtF1KuRb33JXRw7cwmmj5KgiL+McQ2ifVPXiBR4Ciq2lnbeVWONlR CUSw== X-Gm-Message-State: AIVw112Wu8ryiZrSVNAdRO5UTbd/o0w0QKGrBwezDsI28BjyJlKKrV/U NWrrXTMkFsyFxSs0GtbYIw== X-Received: by 10.84.130.104 with SMTP id 95mr16343726plc.411.1501497681385; Mon, 31 Jul 2017 03:41:21 -0700 (PDT) Received: from localhost ([171.50.171.30]) by smtp.gmail.com with ESMTPSA id t14sm19901039pgr.94.2017.07.31.03.41.20 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 31 Jul 2017 03:41:20 -0700 (PDT) From: Pratyush Anand To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 5/5] arm64: fault: re-enable irq if it was disabled for single stepping Date: Mon, 31 Jul 2017 16:10:33 +0530 Message-Id: <9975fac37c34fcc83a43fc797d0dbf7e463a038f.1501496603.git.panand@redhat.com> X-Mailer: git-send-email 2.9.4 In-Reply-To: References: In-Reply-To: References: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170731_034144_140583_55F8AE29 X-CRM114-Status: GOOD ( 13.26 ) 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, Pratyush Anand , will.deacon@arm.com, linux-kernel@vger.kernel.org, takahiro.akashi@linaro.org, huawei.libin@huawei.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 We disable irq before single stepping and re-enable it after it. However, if stepped instruction will cause a fault then we will enter into fault handler with interrupt disabled, which is not desired. But, we should be safe if we re-enable interrupt in fault handler if it was disabled for single stepping. Signed-off-by: Pratyush Anand --- arch/arm64/mm/fault.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index ce5290dacba3..2b88807eb964 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -589,6 +589,8 @@ static const struct fault_info fault_info[] = { { do_bad, SIGBUS, 0, "unknown 63" }, }; +static DEFINE_PER_CPU(bool, irq_enable_needed); + /* * Dispatch a data abort to the relevant handler. */ @@ -597,6 +599,12 @@ asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, { const struct fault_info *inf = esr_to_fault_info(esr); struct siginfo info; + bool *irq_en_needed = this_cpu_ptr(&irq_enable_needed); + + if (*irq_en_needed) { + regs->pstate &= ~PSR_I_BIT; + *irq_en_needed = false; + } if (!inf->fn(addr, esr, regs)) return; @@ -672,8 +680,6 @@ void __init hook_debug_fault_code(int nr, debug_fault_info[nr].name = name; } -static DEFINE_PER_CPU(bool, irq_enable_needed); - asmlinkage int __exception do_debug_exception(unsigned long addr, unsigned int esr, struct pt_regs *regs)