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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 1C1C8C43603 for ; Wed, 11 Dec 2019 16:05:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8C55214D8 for ; Wed, 11 Dec 2019 16:05:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576080310; bh=qzz8hoLUA2ByqBcCK1pZMfBl6ixxXnlSmDmXv8/JiI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=f9xP87XsCgA+DYP76VutmI5kDxQ7G7NoD7u51LGEmVS9oPQMOYVjOwIDWtNzMe/6+ TKOBMmULUBAEftQEAHGnxVHActhi1iQzV6/QQ9o1KiuHPQJup4XEToyD+aIFVsKgB+ RH5EAMMMP22el4FW6IesBmFi+1U8/lkZzxqMlxbQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388879AbfLKQFI (ORCPT ); Wed, 11 Dec 2019 11:05:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:35394 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729985AbfLKPMz (ORCPT ); Wed, 11 Dec 2019 10:12:55 -0500 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 D1F3A24671; Wed, 11 Dec 2019 15:12:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576077174; bh=qzz8hoLUA2ByqBcCK1pZMfBl6ixxXnlSmDmXv8/JiI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WbE8Ap8PPtHt25CEKwR/TTZ9+gjdNkCePsJjl9lTaLla55WtdhXVyClIc1MeYYMrX bYySOTyMFCJBPUPjFR77cATXUT3CuMkjvcHM6vBi8QHDDvi8m6UU8CaKxIMGnqR9cJ ugGOY3b5/I6ydbuieUB3B7v7Su5ajLVMSXpb8emE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jan Stancek , Naresh Kamboju , Christoph Hellwig , "Darrick J . Wong" , Sasha Levin Subject: [PATCH AUTOSEL 5.4 059/134] iomap: fix return value of iomap_dio_bio_actor on 32bit systems Date: Wed, 11 Dec 2019 10:10:35 -0500 Message-Id: <20191211151150.19073-59-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191211151150.19073-1-sashal@kernel.org> References: <20191211151150.19073-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Stancek [ Upstream commit e9f930ac88a8936ccc2d021110c98810cf5aa810 ] Naresh reported LTP diotest4 failing for 32bit x86 and arm -next kernels on ext4. Same problem exists in 5.4-rc7 on xfs. The failure comes down to: openat(AT_FDCWD, "testdata-4.5918", O_RDWR|O_DIRECT) = 4 mmap2(NULL, 4096, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f7b000 read(4, 0xb7f7b000, 4096) = 0 // expects -EFAULT Problem is conversion at iomap_dio_bio_actor() return. Ternary operator has a return type and an attempt is made to convert each of operands to the type of the other. In this case "ret" (int) is converted to type of "copied" (unsigned long). Both have size of 4 bytes: size_t copied = 0; int ret = -14; long long actor_ret = copied ? copied : ret; On x86_64: actor_ret == -14; On x86 : actor_ret == 4294967282 Replace ternary operator with 2 return statements to avoid this unwanted conversion. Fixes: 4721a6010990 ("iomap: dio data corruption and spurious errors when pipes fill") Reported-by: Naresh Kamboju Signed-off-by: Jan Stancek Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin --- fs/iomap/direct-io.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 1fc28c2da2790..7c58f51d7da74 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -318,7 +318,9 @@ zero_tail: if (pad) iomap_dio_zero(dio, iomap, pos, fs_block_size - pad); } - return copied ? copied : ret; + if (copied) + return copied; + return ret; } static loff_t -- 2.20.1