Re: [Xen-devel] [PATCH] VMX: fix vmx_{find,del}_msr() build

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

> From: Jan Beulich [mailto:JBeulich@xxxxxxxx]
> Sent: Wednesday, July 18, 2018 5:39 PM
> 
> >>> On 18.07.18 at 11:36, <wei.liu2@xxxxxxxxxx> wrote:
> > On Mon, Jul 16, 2018 at 10:46:11AM -0600, Jan Beulich wrote:
> >> For a reason that I can't explain, it is only the shim build that fails
> >> for me with an older gcc due to the compiler not recognizing that
> >> apparently uninitialized variables aren't really uninitialized. Pull out
> >> the assignments used by two of the three case blocks and make them
> >> initializers of the variables, as I think I had suggested during review.
> >>
> >> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> >
> > Code:
> >
> > Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>
> >
> > But please update the commit message to say it is caused by compiler
> > optimisation level.
> 
> Sure, now that it's clear what the reason is. It now reads:
> 
> Older gcc at -O2 (and perhaps higher) does not recognize that apparently
> uninitialized variables aren't really uninitialized. Pull out the
> assignments used by two of the three case blocks and make them
> initializers of the variables, as I think I had suggested during review.
> 

Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>

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