Subject: Re: linux-next: build warning after merge of the tip tree

From: "H. Peter Anvin" <[email-masked]>
Date: Fri, 18 Jul 2014 13:05:35 -0700

On 07/18/2014 12:57 PM, Andy Lutomirski wrote:
> 
> This particular warning is IMO in a particularly dumb category: GCC
> optimizes some code and then warns about a construct that wasn't there
> in the original code.  In this case, I think it unrolled a loop and
> discovered that one iteration contained a test that was always true.
> Big deal.
> 
> (OTOH, the code in question was buggy, but not all for the reason that
> GCC thought it was.)
> 

		if (syms[sym_vvar_start] > syms[i] + 4096)
			fail("%s underruns begin_vvar\n",
			     required_syms[i].name);

if i == sym_vvar_start then this is at least a valid warning.  It could
easily be quieted by chaning syms[] to an unsigned array.

	-hpa