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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7A5EC433F5 for ; Tue, 18 Jan 2022 03:18:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240707AbiARDSC (ORCPT ); Mon, 17 Jan 2022 22:18:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353288AbiARDBc (ORCPT ); Mon, 17 Jan 2022 22:01:32 -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 8867AC028C26; Mon, 17 Jan 2022 18:47:01 -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 502E6B8125F; Tue, 18 Jan 2022 02:47:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 091F9C36AE3; Tue, 18 Jan 2022 02:46:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642474019; bh=Z6LnLnvpzRXBhuAU39DeUE7li7MEBSuYocwLtie5v+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sT/uzE2/PhHm0zvaJnBEIRRS2DYid3rfJVv/tPrwmLvdAGFXnBbMZw8VOsLGB2/HW so1DxNGKBYtH5jE5FMSWq4PBG+YEeAuwt2wD6Pee1yhpEXNgYrBFO6mUUZUpjwa7Hj IEb37XhAJE+mp+1mKlP1Cic4tjEMHL29H+pZ31pnNIBNVlD/+0hutFTo62pSY8js// pbdQX461rNJlJCINEsKPVhC9ABYfOVddR6nB2ciMlqrooMZcLBSX/eUWCMqs3ytTXw VbyJb6OOyK2F9KAVov65YqyFksbdZFJnPfvtOEEcdUawGF949UvS6n0+Rb6caZGOYL ZMTtGnobvUiXQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: John David Anglin , Helge Deller , Sasha Levin , James.Bottomley@HansenPartnership.com, svens@stackframe.org, wangkefeng.wang@huawei.com, ebiederm@xmission.com, rmk+kernel@armlinux.org.uk, linux-parisc@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 73/73] parisc: Avoid calling faulthandler_disabled() twice Date: Mon, 17 Jan 2022 21:44:32 -0500 Message-Id: <20220118024432.1952028-73-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118024432.1952028-1-sashal@kernel.org> References: <20220118024432.1952028-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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)) -- 2.34.1