From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH 1/7] libxc: fix uninitialized variable in xc_cpuid_pv_policy() Date: Fri, 3 Jul 2015 15:39:51 +0100 Message-ID: <55969EB7.5040502@citrix.com> References: <1435772232-39085-1-git-send-email-Jennifer.Herbert@citrix.com> <1435772232-39085-2-git-send-email-Jennifer.Herbert@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1435772232-39085-2-git-send-email-Jennifer.Herbert@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jennifer Herbert , xen-devel@lists.xen.org Cc: ian.jackson@eu.citrix.com, wei.liu2@citrix.com, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org On 01/07/15 18:37, Jennifer Herbert wrote: > If xc_domain_get_guest_width were to fail, guest_width is not set, and > hence guest_64bit becomes undefined. > Fix is to initialise to 0, and report error if call fails. > > Signed-off-by: Jennifer Herbert Coverity-ID: 1090350 ~Andrew > --- > tools/libxc/xc_cpuid_x86.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c > index c97f91a..847b701 100644 > --- a/tools/libxc/xc_cpuid_x86.c > +++ b/tools/libxc/xc_cpuid_x86.c > @@ -437,14 +437,16 @@ static void xc_cpuid_pv_policy( > { > DECLARE_DOMCTL; > unsigned int guest_width; > - int guest_64bit; > + int guest_64bit = 0; > char brand[13]; > uint64_t xfeature_mask; > > xc_cpuid_brand_get(brand); > > - xc_domain_get_guest_width(xch, domid, &guest_width); > - guest_64bit = (guest_width == 8); > + if (xc_domain_get_guest_width(xch, domid, &guest_width) == 0) > + guest_64bit = (guest_width == 8); > + else > + ERROR("Could not read guest word width."); > > /* Detecting Xen's atitude towards XSAVE */ > memset(&domctl, 0, sizeof(domctl));