From owner-svn-src-head@freebsd.org Tue Sep 17 14:27:59 2019 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id E2076125863; Tue, 17 Sep 2019 14:27:59 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 46Xlnp6tVKz44w8; Tue, 17 Sep 2019 14:27:58 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id x8HERnIR071898 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Tue, 17 Sep 2019 17:27:52 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua x8HERnIR071898 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id x8HERni2071897; Tue, 17 Sep 2019 17:27:49 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Tue, 17 Sep 2019 17:27:49 +0300 From: Konstantin Belousov To: Toomas Soome Cc: Toomas Soome , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r352421 - head/stand/libsa Message-ID: <20190917142749.GB2559@kib.kiev.ua> References: <201909162028.x8GKS9jK064079@repo.freebsd.org> <20190917085641.GY2559@kib.kiev.ua> <6762A429-F17F-46D1-A55B-BD9C627D6903@me.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6762A429-F17F-46D1-A55B-BD9C627D6903@me.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on tom.home X-Rspamd-Queue-Id: 46Xlnp6tVKz44w8 X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=gmail.com (policy=none); spf=softfail (mx1.freebsd.org: 2001:470:d5e7:1::1 is neither permitted nor denied by domain of kostikbel@gmail.com) smtp.mailfrom=kostikbel@gmail.com X-Spamd-Result: default: False [-2.00 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; DMARC_POLICY_SOFTFAIL(0.10)[gmail.com : No valid SPF, No valid DKIM,none]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all]; RCPT_COUNT_FIVE(0.00)[5]; IP_SCORE_FREEMAIL(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; IP_SCORE(0.00)[ip: (-2.66), ipnet: 2001:470::/32(-4.46), asn: 6939(-3.22), country: US(-0.05)]; FREEMAIL_TO(0.00)[me.com]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Sep 2019 14:27:59 -0000 On Tue, Sep 17, 2019 at 12:05:26PM +0300, Toomas Soome wrote: > > > > On 17 Sep 2019, at 11:56, Konstantin Belousov wrote: > > > > On Mon, Sep 16, 2019 at 08:28:09PM +0000, Toomas Soome wrote: > >> Author: tsoome > >> Date: Mon Sep 16 20:28:08 2019 > >> New Revision: 352421 > >> URL: https://svnweb.freebsd.org/changeset/base/352421 > >> > >> Log: > >> loader: Malloc(0) should return NULL. > >> > >> We really should not allocate anything with size 0. > > Why ? This is quite unexpected from other environments, where > > malloc(0) returns unique object. > > > > Hiding bugs. And, we are not getting unique object, we are getting chunk of memory with payload length of 0 and the memory content depends on if head and tail guards are used - the chunk is with size at least MALLOCALIGN (16 or 64 bytes) and the chunk is from random location of heap. > Yes, exactly, this is how all other mallocs behave.