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 X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF428ECDE44 for ; Wed, 31 Oct 2018 23:07:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7D292064C for ; Wed, 31 Oct 2018 23:07:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ePsLw3qZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A7D292064C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728812AbeKAIHU (ORCPT ); Thu, 1 Nov 2018 04:07:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:54978 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728719AbeKAIHS (ORCPT ); Thu, 1 Nov 2018 04:07:18 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3C00F2064C; Wed, 31 Oct 2018 23:07:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541027227; bh=qwSFJRY47yl1qLewAyDGsq9x1+ZS6GZjbC+D5Cfxh1g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ePsLw3qZbPB5blSntJtAyYgHnM6ydZpigKV0VESE+P9+n6aEQUg9VtnjTSPjiX6Qz YKVIk8Op4dbNOvi5O1HPAzqGPhzjxpoYee8+HXmK6bJFXPPl6QucA4AuGzDnCzN+iN GXhQu3/eiN7w5XQJe30ZzQhnP/qINz8Nu6o/103U= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: David Howells , Dan Williams , Sasha Levin Subject: [PATCH AUTOSEL 4.19 094/146] UAPI: ndctl: Fix g++-unsupported initialisation in headers Date: Wed, 31 Oct 2018 19:04:49 -0400 Message-Id: <20181031230541.28822-94-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181031230541.28822-1-sashal@kernel.org> References: <20181031230541.28822-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Howells [ Upstream commit 9607871f37dc3e717639694b8d0dc738f2a68efc ] The following code in the linux/ndctl header file: static inline const char *nvdimm_bus_cmd_name(unsigned cmd) { static const char * const names[] = { [ND_CMD_ARS_CAP] = "ars_cap", [ND_CMD_ARS_START] = "ars_start", [ND_CMD_ARS_STATUS] = "ars_status", [ND_CMD_CLEAR_ERROR] = "clear_error", [ND_CMD_CALL] = "cmd_call", }; if (cmd < ARRAY_SIZE(names) && names[cmd]) return names[cmd]; return "unknown"; } is broken in a number of ways: (1) ARRAY_SIZE() is not generally defined. (2) g++ does not support "non-trivial" array initialisers fully yet. (3) Every file that calls this function will acquire a copy of names[]. The same goes for nvdimm_cmd_name(). Fix all three by converting to a switch statement where each case returns a string. That way if cmd is a constant, the compiler can trivially reduce it and, if not, the compiler can use a shared lookup table if it thinks that is more efficient. A better way would be to remove these functions and their arrays from the header entirely. Signed-off-by: David Howells Signed-off-by: Dan Williams Signed-off-by: Sasha Levin --- include/uapi/linux/ndctl.h | 48 +++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 27 deletions(-) diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h index 7e27070b9440..2f2c43d633c5 100644 --- a/include/uapi/linux/ndctl.h +++ b/include/uapi/linux/ndctl.h @@ -128,37 +128,31 @@ enum { static inline const char *nvdimm_bus_cmd_name(unsigned cmd) { - static const char * const names[] = { - [ND_CMD_ARS_CAP] = "ars_cap", - [ND_CMD_ARS_START] = "ars_start", - [ND_CMD_ARS_STATUS] = "ars_status", - [ND_CMD_CLEAR_ERROR] = "clear_error", - [ND_CMD_CALL] = "cmd_call", - }; - - if (cmd < ARRAY_SIZE(names) && names[cmd]) - return names[cmd]; - return "unknown"; + switch (cmd) { + case ND_CMD_ARS_CAP: return "ars_cap"; + case ND_CMD_ARS_START: return "ars_start"; + case ND_CMD_ARS_STATUS: return "ars_status"; + case ND_CMD_CLEAR_ERROR: return "clear_error"; + case ND_CMD_CALL: return "cmd_call"; + default: return "unknown"; + } } static inline const char *nvdimm_cmd_name(unsigned cmd) { - static const char * const names[] = { - [ND_CMD_SMART] = "smart", - [ND_CMD_SMART_THRESHOLD] = "smart_thresh", - [ND_CMD_DIMM_FLAGS] = "flags", - [ND_CMD_GET_CONFIG_SIZE] = "get_size", - [ND_CMD_GET_CONFIG_DATA] = "get_data", - [ND_CMD_SET_CONFIG_DATA] = "set_data", - [ND_CMD_VENDOR_EFFECT_LOG_SIZE] = "effect_size", - [ND_CMD_VENDOR_EFFECT_LOG] = "effect_log", - [ND_CMD_VENDOR] = "vendor", - [ND_CMD_CALL] = "cmd_call", - }; - - if (cmd < ARRAY_SIZE(names) && names[cmd]) - return names[cmd]; - return "unknown"; + switch (cmd) { + case ND_CMD_SMART: return "smart"; + case ND_CMD_SMART_THRESHOLD: return "smart_thresh"; + case ND_CMD_DIMM_FLAGS: return "flags"; + case ND_CMD_GET_CONFIG_SIZE: return "get_size"; + case ND_CMD_GET_CONFIG_DATA: return "get_data"; + case ND_CMD_SET_CONFIG_DATA: return "set_data"; + case ND_CMD_VENDOR_EFFECT_LOG_SIZE: return "effect_size"; + case ND_CMD_VENDOR_EFFECT_LOG: return "effect_log"; + case ND_CMD_VENDOR: return "vendor"; + case ND_CMD_CALL: return "cmd_call"; + default: return "unknown"; + } } #define ND_IOCTL 'N' -- 2.17.1