From patchwork Mon Jan 24 18:42:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 536419 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C363FC4332F for ; Mon, 24 Jan 2022 18:53:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344207AbiAXSx4 (ORCPT ); Mon, 24 Jan 2022 13:53:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343611AbiAXSwZ (ORCPT ); Mon, 24 Jan 2022 13:52:25 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B21EC0617A6; Mon, 24 Jan 2022 10:52:14 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A7E5FB81227; Mon, 24 Jan 2022 18:52:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C708BC340E5; Mon, 24 Jan 2022 18:52:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643050332; bh=nF1g3TlmBQAjvdwYb0PgfScODMcjqpRH4mw4fHaeTBE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mG2A3L/i/p0+bxE92vI63bV153IeD/X+bklsBH3IE0QJYIFXXwIrnO0jctyXYogKm xLwpIpz9J9z+dxEY0QwsCYb+tqqrd1vM5J4kEQSpIFRylB11O4d3fFcCWEPDRI+ER0 Gq3vWpf+gmr1qoFs36WlwO9sefhio+70XhKApE/w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John David Anglin , Helge Deller , Sasha Levin Subject: [PATCH 4.4 083/114] parisc: Avoid calling faulthandler_disabled() twice Date: Mon, 24 Jan 2022 19:42:58 +0100 Message-Id: <20220124183929.673037481@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183927.095545464@linuxfoundation.org> References: <20220124183927.095545464@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: John David Anglin [ Upstream commit 9e9d4b460f23bab61672eae397417d03917d116c ] In handle_interruption(), we call faulthandler_disabled() to check whether the fault handler is not disabled. If the fault handler is disabled, we immediately call do_page_fault(). It then calls faulthandler_disabled(). If disabled, do_page_fault() attempts to fixup the exception by jumping to no_context: no_context: if (!user_mode(regs) && fixup_exception(regs)) { return; } parisc_terminate("Bad Address (null pointer deref?)", regs, code, address); Apart from the error messages, the two blocks of code perform the same function. We can avoid two calls to faulthandler_disabled() by a simple revision to the code in handle_interruption(). Note: I didn't try to fix the formatting of this code block. Signed-off-by: John David Anglin Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- arch/parisc/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c index 6f61a17e2485a..55e7ba06511df 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -796,7 +796,7 @@ void notrace handle_interruption(int code, struct pt_regs *regs) * unless pagefault_disable() was called before. */ - if (fault_space == 0 && !faulthandler_disabled()) + if (faulthandler_disabled() || fault_space == 0) { /* Clean up and return if in exception table. */ if (fixup_exception(regs))