From owner-svn-src-all@freebsd.org Mon Jun 10 06:42:39 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id F05AB15B5E21; Mon, 10 Jun 2019 06:42:38 +0000 (UTC) (envelope-from dougm@rice.edu) Received: from mx0a-0010f301.pphosted.com (mx0a-0010f301.pphosted.com [148.163.149.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.pphosted.com", Issuer "Thawte RSA CA 2018" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 687139519F; Mon, 10 Jun 2019 06:42:38 +0000 (UTC) (envelope-from dougm@rice.edu) Received: from pps.filterd (m0102857.ppops.net [127.0.0.1]) by mx0b-0010f301.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5A6fDc6031947; Mon, 10 Jun 2019 01:42:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rice.edu; h=subject : to : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=ricemail; bh=8wLuuqNA5BJ/xYPT7HX3WLMTd7syVvoo7yv06H9cARY=; b=DYCEg+n5wEmKyJCWlHK3KQjvvDv7Y2Wr8qwD1kMRLXgF+kLgAzz30x4wTox4sZRP09Q6 ape8RYeIJhDN5DZSKvpozPGigmcG6T8riw//7FmuwUHyk1RQNSr8sbAYYXPDENpybDBh BtRQ9VF4XIRW6zR9dR4tAZJu48mvHTjNfQM6nHQ4AR4dZs7ZF1sXLBm181dRUtWWiYLT afAsK/+/uXsgpDr1Hf0NaKdlU4Zu5S5qDCD30JCS9kr/oBYL7OFHaUrifObtJJT2KlmA rkjSNYvkpMnn/zxw52LN1qmHYsJee48iSg3BSaIEZ9kMFTduw+xPPd6F0LT+4pCz0Doh jw== Received: from mh1.mail.rice.edu (mh1.mail.rice.edu [128.42.201.20]) by mx0b-0010f301.pphosted.com with ESMTP id 2t07b2hjju-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 10 Jun 2019 01:42:35 -0500 Received-X: from mh1.mail.rice.edu (localhost.localdomain [127.0.0.1]) by mh1.mail.rice.edu (Postfix) with ESMTP id 34348460569; Mon, 10 Jun 2019 01:42:35 -0500 (CDT) Received-X: from mh1.mail.rice.edu (localhost.localdomain [127.0.0.1]) by mh1.mail.rice.edu (Postfix) with ESMTP id 1D1934605E5; Mon, 10 Jun 2019 01:42:35 -0500 (CDT) X-Virus-Scanned: by amavis-2.7.0 at mh1.mail.rice.edu, auth channel Received-X: from mh1.mail.rice.edu ([127.0.0.1]) by mh1.mail.rice.edu (mh1.mail.rice.edu [127.0.0.1]) (amavis, port 10026) with ESMTP id iq_3jNXws1-P; Mon, 10 Jun 2019 01:42:35 -0500 (CDT) Received: from 108-254-203-202.lightspeed.hstntx.sbcglobal.net (108-254-203-202.lightspeed.hstntx.sbcglobal.net [108.254.203.202]) (using TLSv1.2 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: dougm) by mh1.mail.rice.edu (Postfix) with ESMTPSA id B8AB0460569; Mon, 10 Jun 2019 01:42:34 -0500 (CDT) Subject: Re: svn commit: r348843 - head/sys/vm To: Andriy Gapon , Doug Moore , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org References: <201906100307.x5A37BFt099669@repo.freebsd.org> From: Doug Moore Openpgp: preference=signencrypt Autocrypt: addr=dougm@rice.edu; keydata= mQENBFy53VQBCAD2UiGSouAAMcSIax5Sp9JtRSd9dYVuAmSraY7x5yOylq8yJ5IDvHZy5q3a FamaCHMpXxieiD/8yTnHIeHP4bg02oDD3ALs0hMAEz00pZlLdxeXRfDzAlMTqFF6USPjDUI8 J/WH+pciNT68bFVXFYVg+bgp4GIdi2Md8X8zQQnHY0xLyKE9FjVN1MlCk+62B6fFhMQIEvd5 RQdbGd+ljuoORD1ajljwP1waXKBfAN5RnIbAXppokgQvnwNRf1eZ7GnqSiwu0eaTHGBatPgr y2v5N19R5WxP2kiN95xdlJEwdUikAhWO1UncDxvXQoM1e68L/J85JSLLIgzuywKpBBtdABEB AAG0IERvdWdsYXMgVyBNb29yZSA8ZG91Z21AcmljZS5lZHU+iQFUBBMBCAA+FiEEeV41MZJW A65Cl96D6I8hU9O51W4FAly53VQCGwMFCQWjmoAFCwkIBwIGFQoJCAsCBBYCAwECHgECF4AA CgkQ6I8hU9O51W58mgf8D9xOhD9/nqtHKUBDJz/m5DLzLyQVci6RrRFK9hSyQ1QdkG4VvvRL G1MpjsM16f42N41lf9Zhln7ydwpeUVNeGwwZu2S4EiSPOEhGpNOYC1lRjsD5ai9aZwzHcrAz 2PnyWxNJNEawrVdPUOaVlE+uzYe1048FaaB5tmYtooWZm5RZx6YBKSbWyWI8OvEO9BRlcwjr ErOlVlW3TNLpBGyvXYMAseWEozzsdaVbsekw6+7atIUYh6z9oBZXmClVdcpLF5/rtYhjwIIE 7AlWyt9tEJjRhA+2ujfbm96IrL5J8Da557IhjfslB8KcWGT+ynA5QzIrwidqllHMGsed4MAo RLkBDQRcud1UAQgA2xw6CEAjLMhRWjY86mW63fJ7WjMKUOoQS+0Z2yyUh2vI3oWWMgHbVlm2 7bclX+uidxABeh8gVxMcPX68ri1PsmXwDSNA93Jpm+dYwhugbvDZ5EEzn9ze3MNbGEEhx9j0 JYVmHOeSW7v2ia8H1ZxHIS3WzfKdsuFl0S34St9ojmkMzDNsRzZNvLF5wFeQ0cUI712OyBu3 E+T369rgIV6jwwwmbDI/YIWd2kMr6+6u40tbs70j7IpjluB3/XyaolcRdpDER9YUDXtSOL+/ UmhbQ10UrmIrxD1enqYn1gE8GOuv1P4zueU6qg8hc/wYPtggqR8smRjPQPn/OlcSxBnO4QAR AQABiQE8BBgBCAAmFiEEeV41MZJWA65Cl96D6I8hU9O51W4FAly53VQCGwwFCQWjmoAACgkQ 6I8hU9O51W5IYgf9ElaumHGMK89Y9ZQVJOwwlD1QC6DUoluIjYmudu6VkHRxrbE1VQohHAeu amaNA0qzLAL7RgkUs1HmyEOqJg0g51pm73l8pK97ztPqXEarCT0CnAE0atl43AY2TCjg+ANl zktrd4QDPqGOBfYbUCGPYJ7yukXU7cmnyaJx6XnjZDAuyhMDxkuocxVNJa32cV0NYqY9EDjo GfGaJjF20leX/BsGElCzDzlZgfWpNGQjqGuOdYdKNx43J654MO6HxSRT25j09s26VzpvT6rI c0wNdJ4CBE5tseI+YlbwhxGziQh/FEMnTSqxhWt1Ac6o9TqMQIIKoQhcekvT7EX5uvvOnLkB DQRcusvzAQgAvlC3Q5iWVbOxhZ6QXSiZ0p1SG19XZBo7tY5L4Pu6QPNsl/tIWbyDodMdz8vG rG36sRZXlcLOfZhhAHuWKUcoPpJ9H3deHrYZSK7H9LBvNm+0C8n/acRrkAZYch74A4HXlBpc +pMm1SfXufXm7TWII7hAvxpX/2+eaZppEl8eRf+JfNhK+34aYjoONp+wi6Jz/gMS7EfC+gIw jg3ncionUqKXHR/HR+kUzfQpiGEj0KvL0YgEawyzb1UB+D0Jb97OAiqj+s0jd4THS5S7b4He lDHcrlisUZNMtFoRmuG2fKCjwqOQ6+qNdjkhL8flHtkAUOu51WOR+kqAqKKRx6JnkQARAQAB iQLSBBgBCgAmFiEEeV41MZJWA65Cl96D6I8hU9O51W4FAly6y/MCGwIFCQWjmoABoAkQ6I8h U9O51W7A1CAEGQEKAH0WIQR+kHbQAKIFA/vka1CjtHtWP6FLrAUCXLrL818UgAAAAAAuAChp c3N1ZXItZnByQG5vdGF0aW9ucy5vcGVucGdwLmZpZnRoaG9yc2VtYW4ubmV0N0U5MDc2RDAw MEEyMDUwM0ZCRTQ2QjUwQTNCNDdCNTYzRkExNEJBQwAKCRCjtHtWP6FLrKfwB/9JJhuW8pYI egq4N9O416AkIGb7U4WgfSxpn+e8qVL5368LdZ9BMe3CnEJ70gPtdvNPStdkJkeQ+tQHVPBw WkHaCxY9Kw4t+K2sYAGOeePmIhro/V2oDxCjHm/orr6r4XrQur+yvHl6qWliKMyKRSQphJcR jEp4AI/1epzp5ulw0sn4Gjgpp4zkEanuPblPukeu4G+1AeCflyR4D1pWvdQU6rL9zS3MFyDa j/ooh7YDC5qx9Y9HjYcTpPfkSzX9GG2XBmR3+3lo3CW1nAdd3tIBepkdEXEMQpZvPRFb9qfg jyE6V0wC6yG9fxF/TuG8/Trs3WZORa1gFDR0rQROvjHCc/UH/R7Pmbw4s7r/DTl9mGXikXQa VkrCkS99g5D67qerzA1S9SyH7d0iVy3PqFr8vNnwJtB7hjFx6uO2XG75h1CX50q3YYx0gd+U dwcM2GeP5SDQ0fdFoCsPjSTRK5oiD96D85VTbS7EJgF14wHcrBbqulUltE3JSVSIgYy4Jyr4 dF82pM8XWeaVaYAh8yoIDvud5UYRJECIC00VNG1W/wUJKmvIhsFIQXRneEoMvbMpDvP9QvAK WK7E+dYhu/eemFhteDTgbh16AbHcpwkwFWMEke/u393pzSsxKVCrYACxv7aY186fILDrQUpQ qJr40I2R31nvfny8tsCffMIvKtJ98Rw= Message-ID: <21baf615-3356-73a1-52b0-d2f33f4cf49d@rice.edu> Date: Mon, 10 Jun 2019 01:42:34 -0500 User-Agent: Mozilla/5.0 (X11; FreeBSD i386; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-06-10_03:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906100047 X-Rspamd-Queue-Id: 687139519F X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-6.99 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.99)[-0.992,0]; REPLY(-4.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Jun 2019 06:42:39 -0000 -fwrapv concerns signed arithmetic.  This calculation is with unsigned arithmetic, and the possibility of wrapping around to 0 is part of the language. Doug Moore On 6/10/19 1:35 AM, Andriy Gapon wrote: > On 10/06/2019 06:07, Doug Moore wrote: >> Author: dougm >> Date: Mon Jun 10 03:07:10 2019 >> New Revision: 348843 >> URL: https://svnweb.freebsd.org/changeset/base/348843 >> >> Log: >> There are times when a len==0 parameter to mmap is okay. But on a >> 32-bit machine, a len parameter just a few bytes short of 4G, rounded >> up to a page boundary and hitting zero then, is not okay. Return >> failure in that case. >> >> Reported by: pho >> Reviewed by: alc, kib (mentor) >> Tested by: pho >> Differential Revision: https://reviews.freebsd.org/D20580 >> >> Modified: >> head/sys/vm/vm_mmap.c >> >> Modified: head/sys/vm/vm_mmap.c >> ============================================================================== >> --- head/sys/vm/vm_mmap.c Sun Jun 9 22:55:21 2019 (r348842) >> +++ head/sys/vm/vm_mmap.c Mon Jun 10 03:07:10 2019 (r348843) >> @@ -257,7 +257,10 @@ kern_mmap(struct thread *td, uintptr_t addr0, size_t s >> >> /* Adjust size for rounding (on both ends). */ >> size += pageoff; /* low end... */ >> - size = (vm_size_t) round_page(size); /* hi end */ >> + /* Check for rounding up to zero. */ >> + if (round_page(size) < size) > Is this guaranteed to work with all compilers? > I think that some smart compilers may think that this condition is impossible. > Are we finally using -fwrapv or something like it for kernel builds? > >> + return (EINVAL); >> + size = round_page(size); /* hi end */ >> >> /* Ensure alignment is at least a page and fits in a pointer. */ >> align = flags & MAP_ALIGNMENT_MASK; >> >