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 10FB3C4332F for ; Sat, 17 Dec 2022 01:15:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229822AbiLQBPO (ORCPT ); Fri, 16 Dec 2022 20:15:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229453AbiLQBPL (ORCPT ); Fri, 16 Dec 2022 20:15:11 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF16C566DB for ; Fri, 16 Dec 2022 17:14:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671239670; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=YEOj7lSQ2ZgeYSaOTeZ4F4HHem9N0jySn1jpWKoo5ig=; b=ce1ewl1qMZi5KNok5Hf+iWfkdqGkwE4Qc+jX9CKUftD7djp31QDiqsA5UuUsOMF8UXT+2C hb74dvZ0KsLQrgGqQZyAZJGkZQAHQ2r9HtiufJ1kWTWcxk/uQokrx2Rwy8fSqSIPWIzOIL b7thG4rop+NeTLYIx47oGdJAzM0rpzE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-637-rJ2yzcc0MLug9guEPquZmw-1; Fri, 16 Dec 2022 20:14:27 -0500 X-MC-Unique: rJ2yzcc0MLug9guEPquZmw-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DE6D53804534; Sat, 17 Dec 2022 01:14:26 +0000 (UTC) Received: from localhost (ovpn-12-34.pek2.redhat.com [10.72.12.34]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BE9E7492C14; Sat, 17 Dec 2022 01:14:25 +0000 (UTC) Date: Sat, 17 Dec 2022 09:14:22 +0800 From: Baoquan He To: kernel test robot Cc: linux-kernel@vger.kernel.org, oe-kbuild-all@lists.linux.dev, linux-mm@kvack.org, stephen.s.brennan@oracle.com, urezki@gmail.com, willy@infradead.org, akpm@linux-foundation.org, hch@infradead.org Subject: Re: [PATCH v1 3/7] mm/vmalloc.c: allow vread() to read out vm_map_ram areas Message-ID: References: <20221204013046.154960-4-bhe@redhat.com> <202212041124.bwd5pjCd-lkp@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202212041124.bwd5pjCd-lkp@intel.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/04/22 at 11:47am, kernel test robot wrote: > Hi Baoquan, > > I love your patch! Perhaps something to improve: > > [auto build test WARNING on akpm-mm/mm-everything] > > url: https://github.com/intel-lab-lkp/linux/commits/Baoquan-He/mm-vmalloc-c-allow-vread-to-read-out-vm_map_ram-areas/20221204-093322 > base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything > patch link: https://lore.kernel.org/r/20221204013046.154960-4-bhe%40redhat.com > patch subject: [PATCH v1 3/7] mm/vmalloc.c: allow vread() to read out vm_map_ram areas > config: arm-randconfig-r046-20221204 > compiler: arm-linux-gnueabi-gcc (GCC) 12.1.0 > reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # https://github.com/intel-lab-lkp/linux/commit/0bcc4ce1e46418b86eb569175879081116649727 > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Baoquan-He/mm-vmalloc-c-allow-vread-to-read-out-vm_map_ram-areas/20221204-093322 > git checkout 0bcc4ce1e46418b86eb569175879081116649727 > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash > > If you fix the issue, kindly add following tag where applicable > | Reported-by: kernel test robot > > All warnings (new ones prefixed by >>): > > mm/vmalloc.c: In function 'vb_vread': > >> mm/vmalloc.c:3540:23: warning: variable 'offset' set but not used [-Wunused-but-set-variable] > 3540 | unsigned long offset; > | ^~~~~~ Thanks. The local variable 'offset' is needed, the handling in vb_vread() need be improved to cover the case in which reading is started from dirty or free regions. I will add below change to v2. diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 78cae59170d8..6612914459cf 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3526,7 +3522,6 @@ static void vb_vread(char *buf, char *addr, int count) unsigned long offset; unsigned int rs, re, n; - offset = ((unsigned long)addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT; vb = xa_load(&vmap_blocks, addr_to_vb_idx((unsigned long)addr)); spin_lock(&vb->lock); @@ -3547,16 +3542,22 @@ static void vb_vread(char *buf, char *addr, int count) addr++; count--; } - n = (re - rs + 1) << PAGE_SHIFT; + /*it could start reading from the middle of used region*/ + offset = offset_in_page(addr); + n = (re - rs + 1) << PAGE_SHIFT - offset; if (n > count) n = count; - aligned_vread(buf, start, n); + aligned_vread(buf, start+offset, n); buf += n; addr += n; count -= n; } spin_unlock(&vb->lock); + + /* zero-fill the left dirty or free regions */ + if (count) + memset(buf, 0, count); } /**