From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Jan Beulich" <JBeulich@suse.com>
Subject: Re: [PATCH v18 05/16] x86/VPMU: Interface for setting
 PMU mode and flags
Date: Fri, 20 Feb 2015 14:31:21 +0000
Message-ID: <54E75349020000780006212E@mail.emea.novell.com>
References: <1424125619-10851-1-git-send-email-boris.ostrovsky@oracle.com>
	<1424125619-10851-6-git-send-email-boris.ostrovsky@oracle.com>
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To: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: kevin.tian@intel.com, suravee.suthikulpanit@amd.com, andrew.cooper3@citrix.com, tim@xen.org, dietmar.hahn@ts.fujitsu.com, xen-devel@lists.xen.org, Aravind.Gopalakrishnan@amd.com, jun.nakajima@intel.com, dgdegra@tycho.nsa.gov
List-Id: xen-devel@lists.xenproject.org

>>> On 16.02.15 at 23:26, <boris.ostrovsky@oracle.com> wrote:
> +long do_xenpmu_op(unsigned int op, XEN_GUEST_HANDLE_PARAM(xen_pmu_params_t) arg)
> +{
> +    int ret;
> +    struct xen_pmu_params pmu_params;
> +
> +    if ( vpmu_disabled )
> +        return -EINVAL;
> +
> +    ret = xsm_pmu_op(XSM_OTHER, current->domain, op);
> +    if ( ret )
> +        return ret;
> +
> +    /* Check major version when parameters are specified */
> +    switch ( op )
> +    {
> +    case XENPMU_mode_set:
> +    case XENPMU_feature_set:
> +        if ( copy_from_guest(&pmu_params, arg, 1) )
> +            return -EFAULT;
> +
> +        if ( pmu_params.version.maj != XENPMU_VER_MAJ )
> +            return -EINVAL;
> +    }
> +
> +    switch ( op )
> +    {
> +    case XENPMU_mode_set:
> +    {
> +        unsigned int old_mode;
> +        static DEFINE_SPINLOCK(xenpmu_mode_lock);
> +
> +        if ( pmu_params.val & ~(XENPMU_MODE_SELF | XENPMU_MODE_HV) )

I btw also highly doubt that all compiler versions can properly track
the pmu_params is not used uninitialized here.

Jan