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 1DF51C43334 for ; Thu, 14 Jul 2022 11:46:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238004AbiGNLqa (ORCPT ); Thu, 14 Jul 2022 07:46:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229666AbiGNLq3 (ORCPT ); Thu, 14 Jul 2022 07:46:29 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [176.9.125.105]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7D9C5A2E2 for ; Thu, 14 Jul 2022 04:46:27 -0700 (PDT) Received: from mwalle01.kontron.local. (unknown [213.135.10.150]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 24B2622238; Thu, 14 Jul 2022 13:46:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1657799185; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WyZTJmAo73/KD+0kmBp1lm3YUfQV76U2zTjjlCT7XKk=; b=ZVhq0w+T6zIY4iYz0A0E59xP4NvgXGWDEeuDuKv0m6Iom2vTeKYkYKk4rebzUs5s6m/eg4 pERMJLkP5pSTtNgQ2FdFX+iMrFCmKSHFbgp7eicW9+pCHN9Li3swhuMGl1iqlwGRzejCJ9 7s2XF910sDbUUWK5Z+QlO32abpgXgqw= From: Michael Walle To: liuxp11@chinatelecom.cn Cc: linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, Michael Walle Subject: Re: [PATCH] iov_iter: Fix repeated minus operation Date: Thu, 14 Jul 2022 13:46:15 +0200 Message-Id: <20220714114615.3346852-1-michael@walle.cc> X-Mailer: git-send-email 2.30.2 In-Reply-To: <1657707820-124858-1-git-send-email-liuxp11@chinatelecom.cn> References: <1657707820-124858-1-git-send-email-liuxp11@chinatelecom.cn> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > After executing command 'cat /proc/cpuinfo', got a message: > > [ 6.909745] ------------[ cut here ]------------ > [ 6.910267] WARNING: CPU: 0 PID: 76 at lib/iov_iter.c:1026 > iov_iter_pipe+0x34/0x40 > [ 6.910951] Modules linked in: > [ 6.911584] CPU: 0 PID: 76 Comm: cat Not tainted 5.19.0-rc6-next-20220711 #9 > [ 6.911916] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 > [ 6.912668] RIP: 0010:iov_iter_pipe+0x34/0x40 > [ 6.913062] Code: 72 54 39 72 5c 76 23 48 c7 07 00 00 00 00 48 c7 47 08 00 00 > 00 00 c6 07 03 48 89 4f 10 48 89 57 18 89 47 20 89 47 24 c3 0f 0b <0f> 7 > [ 6.914341] RSP: 0018:ffffc900001c7d48 EFLAGS: 00000246 > [ 6.914647] RAX: 0000000000000010 RBX: ffff888004988700 RCX: 0000000000000000 > [ 6.914893] RDX: ffff88800490bc00 RSI: 0000000000000010 RDI: ffffc900001c7d58 > [ 6.915302] RBP: ffffc900001c7e00 R08: 0000000000000000 R09: ffff888004cafad8 > [ 6.915609] R10: 0000000000020000 R11: 0000000000001000 R12: ffff88800490bc00 > [ 6.915856] R13: ffffc900001c7e48 R14: 00000000000002d5 R15: ffff88800490bc00 > [ 6.916352] FS: 00000000016df8c0(0000) GS:ffff88800f600000(0000) Thanks, I'm getting the same warning and also if you do a cat on any sysfs file. > Checking the code, need to delete the duplicate minus in a loop. > > Signed-off-by: Liu Xinpeng Fixes: 3d246b875f31 ("ITER_PIPE: allocate buffers as we go in copy-to-pipe primitives") Tested-by: Michael Walle -michael