Re: [PATCH] KVM: Fix warning in emulator_cmpxchg_emulated

[Sasha Levin <levinsasha928@gmail.com>]

On Thu, 2011-12-08 at 09:04 +0100, Jan Kiszka wrote:
> On 2011-12-08 07:17, Sasha Levin wrote:
> > Make sure 'exchanged' is initialized. Fixes the following warning:
> > 
> > arch/x86/kvm/x86.c: In function 'emulator_cmpxchg_emulated':
> > arch/x86/kvm/x86.c:3794:7: warning: 'exchanged' may be used uninitialized in this function
> > 
> > Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
> > ---
> >  arch/x86/kvm/x86.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index eeeaf2e..9338afc 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -3791,7 +3791,7 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
> >  	gpa_t gpa;
> >  	struct page *page;
> >  	char *kaddr;
> > -	bool exchanged;
> > +	bool exchanged = false;
> >  
> >  	/* guests cmpxchg8b have to be emulated atomically */
> >  	if (bytes > 8 || (bytes & (bytes - 1)))
> 
> Isn't BUG() tagged as no-return in the kernel? Because this
> initialization is obviously unneeded.

It looks like __builtin_unreachable() requires a gcc newer than mine.

-- 

Sasha.