Re: [PATCH] x86, fpu: correct XSAVE xstate size calculation

From: Dave Hansen
Date: Thu Aug 06 2015 - 12:03:30 EST


Here's a correction about what we do today, and it's an important point.
The code I was ripping out in the patch was *really* just for the
XSAVES/compacted case, does *NOT* do anything today since we've disabled
XSAVES.

So perhaps the title here should be:

[PATCH] x86, fpu: correct XSAVES xstate size calculation

/* Option 1, what we have today */

if (!cpu_has_xsaves) {
cpuid(0xD0, 0, &total_blob_size, ...);
return;
}
/*
* This breaks if offset[i]+size[i] != offset[i+1]
* or if alignment is in play. Silly hardware breaks
* this today.
*/
for (i = 0; i < nr_xstates; i++) {
if (!enabled_xstate(i))
continue;
total_blob_size += xstate_sizes[i];
}

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