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=-9.1 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 40DFCC4360F for ; Sat, 30 Mar 2019 01:32:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 12E7F21773 for ; Sat, 30 Mar 2019 01:32:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909570; bh=e9Hgn0yEq3PzbUCkM5o8boIpEj8HdV31aKJFPpHq8vA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=V7LI/oB13y0MK7zuygAuzSNiUN4Nvj/s1aWweyuXQRQTSxGMa8cIfe0AI9i7mlByX nRVLm3jSI8Q+3Q68D0S+1cdRgrJm+3nyIwEzWWbgK7+Fvm/nc0cPqJTu83kJDXTmei S/VtsW70QTRJ0GH2uaU1UhUpFjNC/TQCrrf4ZMJ0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731761AbfC3Bcs (ORCPT ); Fri, 29 Mar 2019 21:32:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:40898 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730836AbfC3Bcr (ORCPT ); Fri, 29 Mar 2019 21:32:47 -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 4901E21773; Sat, 30 Mar 2019 01:32:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909567; bh=e9Hgn0yEq3PzbUCkM5o8boIpEj8HdV31aKJFPpHq8vA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Si9d8vek5CNPFJREkvGKkCx83l3j8l6mXTTcdKR5M53rJEMVoR94e4O0rNV7sfkpG gkAFQPUDchkPXqPMZvDa0g5FRQCyFUTV4IBJnAbwR6mIxMuddzco9Opi1oii6No9Kj 9yKJkqtfYaxkI5u9+kp/pAYo93VkxcCXKwNx9JWA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Pi-Hsun Shih , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 3.18 10/10] include/linux/swap.h: use offsetof() instead of custom __swapoffset macro Date: Fri, 29 Mar 2019 21:32:27 -0400 Message-Id: <20190330013227.1365-10-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190330013227.1365-1-sashal@kernel.org> References: <20190330013227.1365-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pi-Hsun Shih [ Upstream commit a4046c06be50a4f01d435aa7fe57514818e6cc82 ] Use offsetof() to calculate offset of a field to take advantage of compiler built-in version when possible, and avoid UBSAN warning when compiling with Clang: UBSAN: Undefined behaviour in mm/swapfile.c:3010:38 member access within null pointer of type 'union swap_header' CPU: 6 PID: 1833 Comm: swapon Tainted: G S 4.19.23 #43 Call trace: dump_backtrace+0x0/0x194 show_stack+0x20/0x2c __dump_stack+0x20/0x28 dump_stack+0x70/0x94 ubsan_epilogue+0x14/0x44 ubsan_type_mismatch_common+0xf4/0xfc __ubsan_handle_type_mismatch_v1+0x34/0x54 __se_sys_swapon+0x654/0x1084 __arm64_sys_swapon+0x1c/0x24 el0_svc_common+0xa8/0x150 el0_svc_compat_handler+0x2c/0x38 el0_svc_compat+0x8/0x18 Link: http://lkml.kernel.org/r/20190312081902.223764-1-pihsun@chromium.org Signed-off-by: Pi-Hsun Shih Acked-by: Michal Hocko Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/linux/swap.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 1dc0e886227d..054cddb52482 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -143,9 +143,9 @@ struct swap_extent { /* * Max bad pages in the new format.. */ -#define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x) #define MAX_SWAP_BADPAGES \ - ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int)) + ((offsetof(union swap_header, magic.magic) - \ + offsetof(union swap_header, info.badpages)) / sizeof(int)) enum { SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ -- 2.19.1