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 A165FC433F5 for ; Mon, 28 Mar 2022 02:49:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237681AbiC1CvB (ORCPT ); Sun, 27 Mar 2022 22:51:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237678AbiC1Cu6 (ORCPT ); Sun, 27 Mar 2022 22:50:58 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5AD742EFB for ; Sun, 27 Mar 2022 19:49:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1648435759; x=1679971759; h=message-id:date:mime-version:to:cc:references:from: subject:in-reply-to:content-transfer-encoding; bh=9rqPqfcIa1ccW3H6rOJaZsgeTrXk813nKYlbyrcSd64=; b=d0Su/EWdsBrfk6mYQFxuouRgXE2oeqiMQ78xUekp41KRQ0K8ljl7oUUz ibw2qAiFUkcuP9wriGi+fOt6Gsyoih99lqTOfUq2WWEj6QbvlgmsPVkSL 7NOwCix3iw6YmJM7mWIBSNSUT26ovFk7nQXBNnjVZ9DRkTzQtRhOPex7D j2NSp6oPttZbJ/S5nOUX09/uJMBI040cyUIWqS6sazphbHXdOmof3ba0a U+pWfouyQSiGVAMlt3seP251p/xNKKXCJ2s9ESlvam7MwVFweyQt+hOLy gfbwL7OKG6wiwqgDigDrcAzmfon6LaeJt+KRlcWfN8VcI8/72n8/U6jEj w==; X-IronPort-AV: E=McAfee;i="6200,9189,10299"; a="345334471" X-IronPort-AV: E=Sophos;i="5.90,216,1643702400"; d="scan'208";a="345334471" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Mar 2022 19:49:19 -0700 X-IronPort-AV: E=Sophos;i="5.90,216,1643702400"; d="scan'208";a="520833975" Received: from crjohnso-mobl.amr.corp.intel.com (HELO [10.209.122.14]) ([10.209.122.14]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Mar 2022 19:49:19 -0700 Message-ID: <347c75b8-3a48-0758-892a-0d0ac139f740@intel.com> Date: Sun, 27 Mar 2022 19:49:19 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Content-Language: en-US To: Haowen Bai , dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org Cc: linux-kernel@vger.kernel.org References: <1648433573-25735-1-git-send-email-baihaowen@meizu.com> From: Dave Hansen Subject: Re: [PATCH] x86/mm: Directly return instead of using local ret variable In-Reply-To: <1648433573-25735-1-git-send-email-baihaowen@meizu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/27/22 19:12, Haowen Bai wrote: > > diff --git a/arch/x86/mm/pf_in.c b/arch/x86/mm/pf_in.c > index 3f83e31..4eff3ee 100644 > --- a/arch/x86/mm/pf_in.c > +++ b/arch/x86/mm/pf_in.c > @@ -130,7 +130,6 @@ enum reason_type get_ins_type(unsigned long ins_addr) > unsigned char *p; > struct prefix_bits prf; > int i; > - enum reason_type rv = OTHERS; > > p = (unsigned char *)ins_addr; > p += skip_prefix(p, &prf); > @@ -141,7 +140,7 @@ enum reason_type get_ins_type(unsigned long ins_addr) > CHECK_OP_TYPE(opcode, imm_wop, IMM_WRITE); > > exit: > - return rv; > + return OTHERS; > } > #undef CHECK_OP_TYPE > Does this even compile? Take a look at this macro: > #define CHECK_OP_TYPE(opcode, array, type) \ > for (i = 0; i < ARRAY_SIZE(array); i++) { \ > if (array[i] == opcode) { \ > rv = type; \ > goto exit; \ > } \ It uses 'rv'.