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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 72F52CA9EC7 for ; Wed, 30 Oct 2019 14:30:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49128217D9 for ; Wed, 30 Oct 2019 14:30:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="h0t2hUb4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726646AbfJ3OaD (ORCPT ); Wed, 30 Oct 2019 10:30:03 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:47033 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726137AbfJ3OaC (ORCPT ); Wed, 30 Oct 2019 10:30:02 -0400 Received: by mail-lj1-f196.google.com with SMTP id w8so2876519lji.13 for ; Wed, 30 Oct 2019 07:30:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=UDQi5D+Jni0obEk/hrjnnpFb3HIzP7e6/KmAnzzfUzA=; b=h0t2hUb4oT0r62g/cYibJjD1Fyqyoyjgd8JaJBdp8oUdJ7aXI+MoelJSuvU31m5zTW 9t5FudXDw80Z5My1dBKKXgsCu/7Gu9eh73ATRKB2rhIAv7GMWeavnW21688kuF9jpZpY pHRE1y4vCKpMV/jmFLcEaX5CZ/9VFgXcarK09YTh+zaJmfM7uLK0aEDFGASxF1tJ/bLC tx/2yWUM7YlMaRGD+S8pU+7cwTcuigP80RQ993kbcqqxly7AyKZctejgg3d+T2w44YUK p6GXHGwn+arn3+YBZCrYhbJpGGVM8j9kad/eRmovTQxPTGy3BsJpRhEHIrSABScQ8Wsn et0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=UDQi5D+Jni0obEk/hrjnnpFb3HIzP7e6/KmAnzzfUzA=; b=Ym9D3Snf2yUOeAv7tuVge8mFiTsULwAN7CyGsB1B9Dv7yxkzANWbUsqtRHZ7Qf3vNt xxcDSmrCQv6ptx9Y04hsxoe6/duLE36N3Xzzwtxooc1lyzmf6RP3NmI9oQcwfj9jvtay VVElIsKB6vfwkN7+jq+aKCnP8cGXlhmZ/qtowShOcLqFsmjdeTZ+CafoEflzAb4rc7/j opiNSzRto7tyOrAvhofStpC8cT+W55HOlCmdLOzrWlYCt2Yr2KyiQ/NqwuI4Ft43txnd FkRAkOPfUlZdHpI9SRVSXnFPt87mukD3KyQyGzoNOnfDp+53GTQ7ah+HR6dOlFtkOHvg VfRA== X-Gm-Message-State: APjAAAV/THMqlnHcNFgpq9fDcfPOqgJmNjC4fOl0UDBXoTwT41lFzneo kSEjPrtxN02oqr+Pbvfs/xQ= X-Google-Smtp-Source: APXvYqx/6ls83NprcmJjVqcPOseDGmZ24WPegNnd0fqzJOSCj4K/d9bGCTxDyewu+1FbJJXi3uqHXg== X-Received: by 2002:a2e:8545:: with SMTP id u5mr7565ljj.213.1572445800371; Wed, 30 Oct 2019 07:30:00 -0700 (PDT) Received: from pc636 ([37.139.158.167]) by smtp.gmail.com with ESMTPSA id s7sm32320ljo.98.2019.10.30.07.29.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Oct 2019 07:29:59 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Wed, 30 Oct 2019 15:29:51 +0100 To: Daniel Axtens Cc: kasan-dev@googlegroups.com, linux-mm@kvack.org, x86@kernel.org, aryabinin@virtuozzo.com, glider@google.com, luto@kernel.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, dvyukov@google.com, christophe.leroy@c-s.fr, linuxppc-dev@lists.ozlabs.org, gor@linux.ibm.com Subject: Re: [PATCH v10 1/5] kasan: support backing vmalloc space with real shadow memory Message-ID: <20191030142951.GA24958@pc636> References: <20191029042059.28541-1-dja@axtens.net> <20191029042059.28541-2-dja@axtens.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191029042059.28541-2-dja@axtens.net> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Daniel > > @@ -1294,14 +1299,19 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) > spin_lock(&free_vmap_area_lock); > llist_for_each_entry_safe(va, n_va, valist, purge_list) { > unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT; > + unsigned long orig_start = va->va_start; > + unsigned long orig_end = va->va_end; > > /* > * Finally insert or merge lazily-freed area. It is > * detached and there is no need to "unlink" it from > * anything. > */ > - merge_or_add_vmap_area(va, > - &free_vmap_area_root, &free_vmap_area_list); > + va = merge_or_add_vmap_area(va, &free_vmap_area_root, > + &free_vmap_area_list); > + > + kasan_release_vmalloc(orig_start, orig_end, > + va->va_start, va->va_end); > I have some questions here. I have not analyzed kasan_releace_vmalloc() logic in detail, sorry for that if i miss something. __purge_vmap_area_lazy() deals with big address space, so not only vmalloc addresses it frees here, basically it can be any, starting from 1 until ULONG_MAX, whereas vmalloc space spans from VMALLOC_START - VMALLOC_END: 1) Should it be checked that vmalloc only address is freed or you handle it somewhere else? if (is_vmalloc_addr(va->va_start)) kasan_release_vmalloc(...) 2) Have you run any bencmarking just to see how much overhead it adds? I am asking, because probably it make sense to add those figures to the backlog(commit message). For example you can run: sudo ./test_vmalloc.sh performance and sudo ./test_vmalloc.sh sequential_test_order=1 Thanks! -- Vlad Rezki