Messages in this thread | | | Date | Wed, 26 Aug 2009 10:27:15 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH 1/1] XEN: enlighten, use uninitialized_var(cx) |
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On 08/25/2009 11:09 PM, Ingo Molnar wrote: >> >> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c >> index e90540a..5ab75e2 100644 >> --- a/arch/x86/xen/enlighten.c >> +++ b/arch/x86/xen/enlighten.c >> @@ -202,7 +202,7 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx, >> >> static __init void xen_init_cpuid_mask(void) >> { >> - unsigned int ax, bx, cx, dx; >> + unsigned int ax, bx, uninitialized_var(cx), dx; > > Please dont use uninitialized_var(), it's an unreliable facility: if > this variable ever grows a real used-without-initialization bug in > the future, the compiler warning is turned off permanently. It's > rare but might happen. We are better off with initializing it to > zero. >
I hadn't seen this thread, but I pushed a patch to x86/urgent to do exactly that while I was committing the Xen crash patch last night.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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