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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 068BEC76196 for ; Tue, 28 Mar 2023 10:14:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9B2746B0072; Tue, 28 Mar 2023 06:14:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9629C6B0074; Tue, 28 Mar 2023 06:14:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 82A046B0075; Tue, 28 Mar 2023 06:14:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 7308D6B0072 for ; Tue, 28 Mar 2023 06:14:41 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 39752ABB5A for ; Tue, 28 Mar 2023 10:14:41 +0000 (UTC) X-FDA: 80617897962.29.8F3A209 Received: from mail-yb1-f176.google.com (mail-yb1-f176.google.com [209.85.219.176]) by imf14.hostedemail.com (Postfix) with ESMTP id 80DF2100003 for ; Tue, 28 Mar 2023 10:14:39 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=jFhXi0OY; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf14.hostedemail.com: domain of elver@google.com designates 209.85.219.176 as permitted sender) smtp.mailfrom=elver@google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1679998479; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Wxx7pqmkD/seHpGsWDBmNccJaAtu0PA/48RM8nZtDsM=; b=3B/X56Tl38vd8zIt+N8rYwKWYsEraUGg3y8FKSFsHDVg/9ayj2VZ4376MZ7cvFvq2t1Jf5 uXclWKsAi45014G2VxYAK7Iwttri3LBIcLDZ2KE7jqC3AeEo0drpneQs6uXL6pVIBV4BMv XTFsxvikBtNZSDC7UEka0jQ8MS0vh1M= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=jFhXi0OY; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf14.hostedemail.com: domain of elver@google.com designates 209.85.219.176 as permitted sender) smtp.mailfrom=elver@google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1679998479; a=rsa-sha256; cv=none; b=8CKwy58pxZnceG5omGr1yv5j511rPihpLpODXe6b7pDl8AIz+BNWFCvzQTQSj33Ba9xBtq 2rFJmur1SoAAxmlBQNhkthPZT/IjfSRwQUxovdqnoFUwgKFgj0q+g81OTI2QDFOiVoyMxU lq4R7VZrQyu1v6r6tHKWOsNRDQrDN6Q= Received: by mail-yb1-f176.google.com with SMTP id p15so14301783ybl.9 for ; Tue, 28 Mar 2023 03:14:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1679998478; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=Wxx7pqmkD/seHpGsWDBmNccJaAtu0PA/48RM8nZtDsM=; b=jFhXi0OY4+lGYplogq3AMQccQZ8/tpc7UyCmJ91GOCv8/aBsVRIFxcjRBhdsE3q8kZ UaCpbkb8wp8NaUMd2yBj8H3YyatofCGMio1i5lQreeR9AhAJVGe/4i76xIUREN8CFkLy oxsfzpCQcad3Y33hoczdEiBpiMwzwSySFyWtz196Ni0K2C3xIJWiIsoaTl5qXPhilFXw nqrmYH8zbIrBiv9qGou6rJXiVAlYF9MKUZOfc3DRF58IejU95v0dq949mTI1ew7CEV99 hINMcM5tesgqAdYjUYLROrKRAsYdQinsBMTqRrCUkDvlFV50GscrPVATbKnkEe+IpeRA XMNA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679998478; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Wxx7pqmkD/seHpGsWDBmNccJaAtu0PA/48RM8nZtDsM=; b=hiBdYdGm2VoRcFgT83EgwgJIVX0RLmhcq4tDplvCdeaMKOPyyCNUqI2SURR9YzbE+p oC3I+A8tr+b/xNPKoAj2k0KRpHHKJGndGu4+ocsq31q27zkiRSJFNYOwgjKwJ9PITBw9 3aOmtl6W0AXVFd5wixUJBiBD5WBPemM3iPqJMzGSXTWuUvmVrKa+14c4DaY+TaOFhHry Vyz7WvE0qWKnAQbGqa0Gb8UuYle213W9MMXHNVRx0yphyOOijRD+mM9nNv8eRLwUNRhE hmGMDl/U7fKbTcfcS1hd6Hw9Zeqf9Oy/3J+qVtgt+O2QWKtC/PRdTZvKXfxBeNAjomuw f/lw== X-Gm-Message-State: AAQBX9e0TeR7xCkEp9Rmgx7HAEEyYT+0ufhN7Ps0aDaI0W056QvWGo/R IE6Aj3eCgMopr0UdUkphnfrfbmuhkAzEt6eO8WwwTA== X-Google-Smtp-Source: AKy350ZMvZiHe2MYvlI8H0eOSo5035+0N51QrPGuiIB378E8P54GgnYFvxLt7XdIBv3bTc5OUmPmQvyRQPgWJQ6MSEE= X-Received: by 2002:a25:aaae:0:b0:b50:de89:68da with SMTP id t43-20020a25aaae000000b00b50de8968damr14945884ybi.32.1679998478582; Tue, 28 Mar 2023 03:14:38 -0700 (PDT) MIME-Version: 1.0 References: <20230328095807.7014-1-songmuchun@bytedance.com> <20230328095807.7014-3-songmuchun@bytedance.com> In-Reply-To: <20230328095807.7014-3-songmuchun@bytedance.com> From: Marco Elver Date: Tue, 28 Mar 2023 12:14:02 +0200 Message-ID: Subject: Re: [PATCH 2/6] mm: kfence: check kfence pool size at building time To: Muchun Song Cc: glider@google.com, dvyukov@google.com, akpm@linux-foundation.org, jannh@google.com, sjpark@amazon.de, muchun.song@linux.dev, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 80DF2100003 X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: 1zasmtrg54q4g8nxtshy3xet1w96ucyj X-HE-Tag: 1679998479-109024 X-HE-Meta: U2FsdGVkX1+qQ7FhLRjMselWtwuB8SfibbY+6PW0RX6YczjwXZGYeA1zv+V84F92QFXhP9kdsRTFS3Lj7UpPvTcOsaVfVy+LEKTFCotmmN4N8xi/I4Bj2UQXNkfcD2rNVRCILhQwnYQw4Qi47NvZIzffIBj7WhAZB8kMGJrA4Drxj1P8zSMFoyzRmK4ACoptU/6jiLMteByl2+jX6wgVAU0PEHGKMEY7snMVIfml+H/If9bDOSTIq8Rv+0/6FeUYB0DPrXg5T8AsixC8+IEn9nTOQHz0yK9T2bXfqExGnMoHG3wN4+ktXHgKSOOGV3Q+j7CYpUsWVTahREVT3Od8hqPqJ3uvJ/uQpe8xr4YSUoL/p6tiI2EMPmFEpHz3WflQOSQBRX79vY1c1N/Bu6CjRb485Z2mB/Z+kALeAOS1QNha9UvT/eccmrgcmcloL/+cNd1qyQlHx2hu/0+z674SJUQ2COtv7QwQO7BzsMaUFLiY7IyIPfZkCL5Ro5qX6ExDYec5VvafrkR9TzOC6NABpw7Z+tpNd6mlFqAqIT7rWbPnAI8fIfBfh5kpamKl/IiVDre/3ihpURO9BcqAFpyZrv9Vtpg373ZardM9sz3QDJ2nrChZ7rkIlngjTkHq4B4THsGYFD4EWwFWLkLnyDD6xE/EKd9cSEY8UZg+10l2wLmvGjcRiKAXXFpovhY9DaviK91ZZt8h06fOGH4Y383OPtL9ttgIwSd5T0HWfxJ/q7TVWvex8mrYCfDNz+JQcKtBJzjRgO5o/QMO6P2UiuoCgMJs9GMjI+O4+j7SzjFyt1iBxR5CuJkTGP8D9RARL07Ppt1wH94tjd33EFiQDj+YWIH2KQ9h8iVhpPFLrFXZTmTV9kwIWc//lYg/dCy62q6QllKOb3X7Hl9fVUHbee6ycW6IVnxI0T79tLhOKsOAf65QfNLAO/xVTjOfzigHhdgqrn9ESjX6xw0xxaaGIkt atPmlxVB Lgke6xmdnBp8nwT8YDlBexVXN0MPOMlkIKVUyLWojDIes/iHYA1ms+Z9jb4J/SxzYQzr5XNhRpYv6KFeH4zSWgD9db54kVOW6VwuqvOFQN+ciEtdwsHDK/2JTaHe0T9oL7ZnMrtEhlDjiycTtJRY6YVG063Af9B6o4bIEC6LhtPtBIfkcZIJb+VTkczyEiPUtCwdiq9GQgB5TgbOpNaAI6H/Gdj8S7Hh5xgZ85BwVcUbvM3Nx+wQ3PcDyznpqTdD9rX/r0OH8S7N+53owbOc+QKQOwyNsnOou0qtvW6hcJy7IArKdXEEFjJFgyBYqSE7p/zS7JKvadhuqQP3zrHDV32H2Kv0ks7cn/jt4kb+Np6Je9zA= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 28 Mar 2023 at 11:58, 'Muchun Song' via kasan-dev wrote: > > Check kfence pool size at building time to expose problem ASAP. > > Signed-off-by: Muchun Song > --- > mm/kfence/core.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > index de62a84d4830..6781af1dfa66 100644 > --- a/mm/kfence/core.c > +++ b/mm/kfence/core.c > @@ -841,10 +841,9 @@ static int kfence_init_late(void) > return -ENOMEM; > __kfence_pool = page_to_virt(pages); > #else > - if (nr_pages > MAX_ORDER_NR_PAGES) { > - pr_warn("KFENCE_NUM_OBJECTS too large for buddy allocator\n"); > - return -EINVAL; > - } > + BUILD_BUG_ON_MSG(get_order(KFENCE_POOL_SIZE) > MAX_ORDER, > + "CONFIG_KFENCE_NUM_OBJECTS is too large for buddy allocator"); > + It's perfectly valid to want to use KFENCE with a very large pool that is initialized on boot, and simply sacrifice the ability to initialize late. Nack.