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 ACB28C433FE for ; Tue, 18 Jan 2022 02:49:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346485AbiARCtD (ORCPT ); Mon, 17 Jan 2022 21:49:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345832AbiARCcF (ORCPT ); Mon, 17 Jan 2022 21:32:05 -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 2FF5BC06173F; Mon, 17 Jan 2022 18:31:36 -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 E0CF2B811FF; Tue, 18 Jan 2022 02:31:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABAA9C36AE3; Tue, 18 Jan 2022 02:31:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642473093; bh=G82Q4cPxhw81sOqVHOtuTQNejvoexVwt2CxtmuQC0No=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UhBXAq8MbeRdIMIpi59YBZTwE+ZkpXKt0+k0PDwX3fg6Ehw6QIeoEF3D/4/jqlSn7 0znNuUW9eEEGhHjec2eq+0u6OCNKKMEw3nLR3pogV3wPehnOMmgWUGlZsWmtlPe+AE I1bn1qBlWy1C6tZ2X9EzvnTELyMuxaMXl+Az2RrUkXXw48F9oLOh3vm4Xqe72+Ax95 yNSCmhUy2FLfxIqUYFT6/oqzIdoXKHd20DDJ2rpV6bUSE+PtPjhoL60WTRRKKwogBB NDq8rLZzYLGhg3Z+u1rZTKwAs8eSPKlIp9maFaeVmE+U1QBzrKPpTG4l0r66FJkOEA pviPKerGtdUOQ== 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, mpe@ellerman.id.au, wangkefeng.wang@huawei.com, ebiederm@xmission.com, linux-parisc@vger.kernel.org Subject: [PATCH AUTOSEL 5.16 211/217] parisc: Avoid calling faulthandler_disabled() twice Date: Mon, 17 Jan 2022 21:19:34 -0500 Message-Id: <20220118021940.1942199-211-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118021940.1942199-1-sashal@kernel.org> References: <20220118021940.1942199-1-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 892b7fc8f3c45..eb41fece19104 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -785,7 +785,7 @@ 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