Re: [Xen-devel] Uninitialized variables in hvm_event_breakpoint (Re: New Defects reported by Coverity Scan for XenProject)

[Corneliu ZUZU <czuzu@xxxxxxxxxxxxxxx>]

On 2/18/2016 12:01 PM, Ian Campbell wrote:
> On Wed, 2016-02-17 at 16:02 -0800, scan-admin@xxxxxxxxxxxx wrote:
> > Hi,
> >
> > Please find the latest report on new defect(s) introduced to XenProject
> > found with Coverity Scan.
> >
> > 1 new defect(s) introduced to XenProject found with Coverity Scan.
> > 4 defect(s), reported by Coverity Scan earlier, were marked fixed in the
> > recent build analyzed by Coverity Scan.
> >
> > New defect(s) Reported-by: Coverity Scan
> > Showing 1 of 1 defect(s)
> >
> >
> > ** CID 1353192:  Uninitialized variables  (UNINIT)
> > /xen/arch/x86/hvm/event.c: 176 in hvm_event_breakpoint()
> This appears to have been introduced by:
>      commit
>      557c7873f35aa39bd84977b28948457b1b342f92
>      Author: Corneliu ZUZU <czuzu@bitdef
>      ender.com>
>      Date:   Mon Feb 15 14:14:16 2016 +0100
>
>          x86: merge 2 hvm_event_... functions into 1
>          
>          This patch merges almost identical functions hvm_event_int3 and
>          hvm_event_single_step into a single function called 
> hvm_event_breakpoint.
>          Also fixes event.c file header comment in the process.
>          
>          Signed-off-by: Corneliu ZUZU <    czuzu@xxxxxxxxxxxxxxx    >
>          Acked-by: Razvan Cojocaru <    rcojocaru@xxxxxxxxxxxxxxx    >
>          Acked-by: Jan Beulich <    jbeulich@xxxxxxxx    >
>
>
> hvm_event_breakpoint calls hvm_event_traps(&req) and if sync is true that
> ors some bits into req->flags which was never initialised.
>
> > _________________________________________________________________________
> > _______________________________
> > *** CID 1353192:  Uninitialized variables  (UNINIT)
> > /xen/arch/x86/hvm/event.c: 176 in hvm_event_breakpoint()
> > 170
> > 171     int hvm_event_breakpoint(unsigned long rip,
> > 172                              enum hvm_event_breakpoint_type type)
> > 173     {
> > 174         struct vcpu *curr = current;
> > 175         struct arch_domain *ad = &curr->domain->arch;
> > > > >      CID 1353192:  Uninitialized variables  (UNINIT)
> > > > >      Declaring variable "req" without initializer.
> > 176         vm_event_request_t req;
> > 177
> > 178         switch ( type )
> > 179         {
> > 180         case HVM_EVENT_SOFTWARE_BREAKPOINT:
> > 181             if ( !ad->monitor.software_breakpoint_enabled )
> >
> >
> > _________________________________________________________________________
> > _______________________________
> > To view the defects in Coverity Scan visit, https://scan.coverity.com/pro
> > jects/xenproject?tab=overview
> >
> > To manage Coverity Scan email notifications for
> > "ian.campbell@xxxxxxxxxx", click https://scan.coverity.com/subscriptions/
> > edit?email=ian.campbell%40citrix.com&token=1ce0fc428b9f94f66fd8d1ecf6cbb7
> > 6a
Sorry, my bad, I didn't know struct-initialization using labels sets all 
the other fields to zero.
Shall I submit a fix for this issue?

Corneliu.

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