From patchwork Mon Jan 24 18:43:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 536132 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 299A3C2BA4C for ; Mon, 24 Jan 2022 19:40:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355151AbiAXTkF (ORCPT ); Mon, 24 Jan 2022 14:40:05 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:57812 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353985AbiAXTfn (ORCPT ); Mon, 24 Jan 2022 14:35:43 -0500 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 97DC8B8122A; Mon, 24 Jan 2022 19:35:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE896C340E7; Mon, 24 Jan 2022 19:35:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643052941; bh=Z6LnLnvpzRXBhuAU39DeUE7li7MEBSuYocwLtie5v+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UJoHSb0WWm4pv0sW0A01Nvkc6yoWvHsDaOQNhDQ9ULKBbQ/YmZzhkoEPZCbJG+cIU 92Eb/kTLXbnACWxZTxLiIOjQ1xN+wf4+8d77eTBkjUmCfnHWUEPMKClmORUhq7kV7R 9VcNqWaqMTy1jplCGOvdbidHUPemzGAMW4u/4tH0= 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 5.4 223/320] parisc: Avoid calling faulthandler_disabled() twice Date: Mon, 24 Jan 2022 19:43:27 +0100 Message-Id: <20220124184001.578089440@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183953.750177707@linuxfoundation.org> References: <20220124183953.750177707@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 82fc011894889..2a1060d747a5d 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -783,7 +783,7 @@ 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))