From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34842) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fKgcS-0004oe-JA for qemu-devel@nongnu.org; Mon, 21 May 2018 04:56:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fKgcO-0002eb-MG for qemu-devel@nongnu.org; Mon, 21 May 2018 04:56:40 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58310 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fKgcO-0002dP-Hi for qemu-devel@nongnu.org; Mon, 21 May 2018 04:56:36 -0400 Date: Mon, 21 May 2018 09:56:27 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20180521085627.GD23090@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <20180514171913.17664-1-berrange@redhat.com> <20180514171913.17664-2-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 1/3] i386: fix regression parsing multiboot initrd modules List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: QEMU Developers , Eduardo Habkost , "Michael S. Tsirkin" , Markus Armbruster , Paolo Bonzini , Richard Henderson On Fri, May 18, 2018 at 06:54:48PM +0100, Peter Maydell wrote: > On 14 May 2018 at 18:19, Daniel P. Berrang=C3=A9 = wrote: > > The logic for parsing the multiboot initrd modules was messed up in > > > > commit 950c4e6c94b15cd0d8b63891dddd7a8dbf458e6a > > Author: Daniel P. Berrang=C3=A9 > > Date: Mon Apr 16 12:17:43 2018 +0100 > > > > opts: don't silently truncate long option values > > > > Causing the length to be undercounter, and the number of modules over > > counted. It also passes NULL to get_opt_value() which was not robust > > at accepting a NULL value. > > > > Signed-off-by: Daniel P. Berrang=C3=A9 > > --- > > hw/i386/multiboot.c | 3 +-- > > util/qemu-option.c | 4 +++- > > 2 files changed, 4 insertions(+), 3 deletions(-) > > > > diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c > > index 7a2953e26f..8e26545814 100644 > > --- a/hw/i386/multiboot.c > > +++ b/hw/i386/multiboot.c > > @@ -292,8 +292,7 @@ int load_multiboot(FWCfgState *fw_cfg, > > cmdline_len +=3D strlen(kernel_cmdline) + 1; > > if (initrd_filename) { > > const char *r =3D get_opt_value(initrd_filename, NULL); > > - cmdline_len +=3D strlen(r) + 1; > > - mbs.mb_mods_avail =3D 1; > > + cmdline_len +=3D strlen(initrd_filename) + 1; > > while (1) { > > mbs.mb_mods_avail++; > > r =3D get_opt_value(r, NULL); > > diff --git a/util/qemu-option.c b/util/qemu-option.c > > index 58d1c23893..8a68bc2314 100644 > > --- a/util/qemu-option.c > > +++ b/util/qemu-option.c > > @@ -75,7 +75,9 @@ const char *get_opt_value(const char *p, char **val= ue) > > size_t capacity =3D 0, length; > > const char *offset; > > > > - *value =3D NULL; > > + if (value) { > > + *value =3D NULL; > > + } > > while (1) { > > offset =3D strchr(p, ','); > > if (!offset) { >=20 > Don't we delete this check again in patch 3? If we're > going to fix this by making multiboot.c not pass in NULL pointers, > is there a reason not to simply do that? That is correct, however, I wanted to do a really simple fix that address= ed the crasher regression, so that aspect of the fix wasn't obscured by the bigger refactoring I do in 2 & 3. Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|