From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1XcnKB-0004zG-0K for mharc-qemu-trivial@gnu.org; Fri, 10 Oct 2014 23:26:31 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37153) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XcnK4-0004ru-FF for qemu-trivial@nongnu.org; Fri, 10 Oct 2014 23:26:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XcnJz-0006X6-IA for qemu-trivial@nongnu.org; Fri, 10 Oct 2014 23:26:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:17186) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XcnJn-0006WH-2J; Fri, 10 Oct 2014 23:26:07 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s9B3Q2MG003940 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 10 Oct 2014 23:26:02 -0400 Received: from [10.3.113.64] (ovpn-113-64.phx2.redhat.com [10.3.113.64]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s9B3Q24P031822; Fri, 10 Oct 2014 23:26:02 -0400 Message-ID: <5438A349.9090403@redhat.com> Date: Fri, 10 Oct 2014 21:26:01 -0600 From: Eric Blake Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Gonglei , Zhanghailiang References: <1412996048-6384-1-git-send-email-arei.gonglei@huawei.com> <54389FB1.8040207@huawei.com> <5438A223.2040402@huawei.com> In-Reply-To: <5438A223.2040402@huawei.com> OpenPGP: url=http://people.redhat.com/eblake/eblake.gpg Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="j1j57A6oxkKNOqBq4MSuP6AgjBPfnNjEt" X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: "kwolf@redhat.com" , "Huangweidong \(C\)" , "qemu-trivial@nongnu.org" , "qemu-devel@nongnu.org" , "stefanha@redhat.com" , "pbonzini@redhat.com" Subject: Re: [Qemu-trivial] [Qemu-devel] [PATCH] oslib-posix: change free to g_free X-BeenThere: qemu-trivial@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 11 Oct 2014 03:26:29 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --j1j57A6oxkKNOqBq4MSuP6AgjBPfnNjEt Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 10/10/2014 09:21 PM, Gonglei wrote: >=20 > Actually, I had noted that C standard says it is a no-operation. > But that doesn't mean that every C-library handles it like that. EVERY libc that is C89 compliant handles it like that. The last platform that failed on free(NULL) was SunOS 4, which is such museum-ware it's not funny. There is no need to cater to platforms from 25 years ago. > Some people saw crashes for free(NULL), so it's best to avoid > calling the free in the first place (caller) or using g_free() in qemu= _vfree(). Absolutely not. g_free is unsafe to use except for pointers from g_malloc, which is NOT the case that qemu_vfree is used on. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --j1j57A6oxkKNOqBq4MSuP6AgjBPfnNjEt Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg iQEcBAEBCAAGBQJUOKNJAAoJEKeha0olJ0NqxEYH/2o34zhb+9uiAMNzK8GjSsET hecaFPBawd0VASl5WRK4KAWPp5I2RnzSUuLnYVBcwx2mlXptUfyvB59StxbvuL9V jz2IPQvMlq4ybk7sUSdlvCe2XbHOFuIVnshuCZ+zT+wRBOK+b+jjbulIypLVV7RN 4zVIRZAzC73vSnIboLNtcSixlxkKTm8nrYQ7/bPVc89jvaJVB1YLX86OJwosWO9w 17rq6aSOPGRZMUM4PaNLll3QlpuOdxhcfD2Ed9mS1YSQ2KPsV/wFVUrRSBflcynw vnGPmDD5AJu75ffA6WxYohIyUCFqOwO4U179kZMb+HzSb2oWvZOK9Ygo3gBZJE8= =FCg5 -----END PGP SIGNATURE----- --j1j57A6oxkKNOqBq4MSuP6AgjBPfnNjEt-- From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37130) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XcnJu-0004ml-Ha for qemu-devel@nongnu.org; Fri, 10 Oct 2014 23:26:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XcnJn-0006WR-Ad for qemu-devel@nongnu.org; Fri, 10 Oct 2014 23:26:14 -0400 Message-ID: <5438A349.9090403@redhat.com> Date: Fri, 10 Oct 2014 21:26:01 -0600 From: Eric Blake MIME-Version: 1.0 References: <1412996048-6384-1-git-send-email-arei.gonglei@huawei.com> <54389FB1.8040207@huawei.com> <5438A223.2040402@huawei.com> In-Reply-To: <5438A223.2040402@huawei.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="j1j57A6oxkKNOqBq4MSuP6AgjBPfnNjEt" Subject: Re: [Qemu-devel] [PATCH] oslib-posix: change free to g_free List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gonglei , Zhanghailiang Cc: "kwolf@redhat.com" , "Huangweidong (C)" , "qemu-trivial@nongnu.org" , "qemu-devel@nongnu.org" , "stefanha@redhat.com" , "pbonzini@redhat.com" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --j1j57A6oxkKNOqBq4MSuP6AgjBPfnNjEt Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 10/10/2014 09:21 PM, Gonglei wrote: >=20 > Actually, I had noted that C standard says it is a no-operation. > But that doesn't mean that every C-library handles it like that. EVERY libc that is C89 compliant handles it like that. The last platform that failed on free(NULL) was SunOS 4, which is such museum-ware it's not funny. There is no need to cater to platforms from 25 years ago. > Some people saw crashes for free(NULL), so it's best to avoid > calling the free in the first place (caller) or using g_free() in qemu= _vfree(). Absolutely not. g_free is unsafe to use except for pointers from g_malloc, which is NOT the case that qemu_vfree is used on. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --j1j57A6oxkKNOqBq4MSuP6AgjBPfnNjEt Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg iQEcBAEBCAAGBQJUOKNJAAoJEKeha0olJ0NqxEYH/2o34zhb+9uiAMNzK8GjSsET hecaFPBawd0VASl5WRK4KAWPp5I2RnzSUuLnYVBcwx2mlXptUfyvB59StxbvuL9V jz2IPQvMlq4ybk7sUSdlvCe2XbHOFuIVnshuCZ+zT+wRBOK+b+jjbulIypLVV7RN 4zVIRZAzC73vSnIboLNtcSixlxkKTm8nrYQ7/bPVc89jvaJVB1YLX86OJwosWO9w 17rq6aSOPGRZMUM4PaNLll3QlpuOdxhcfD2Ed9mS1YSQ2KPsV/wFVUrRSBflcynw vnGPmDD5AJu75ffA6WxYohIyUCFqOwO4U179kZMb+HzSb2oWvZOK9Ygo3gBZJE8= =FCg5 -----END PGP SIGNATURE----- --j1j57A6oxkKNOqBq4MSuP6AgjBPfnNjEt--