On Tue, Nov 05, 2024 at 04:57:57PM +0100, Phil Dennis-Jordan wrote:
> The handling for CPUID function 0xD (supported XSAVE features) was
> improved in a recent patch. Unfortunately, this appears to have
> introduced undefined behaviour for cases where ecx > 30, as the result
> of (1 << idx) is unde
The handling for CPUID function 0xD (supported XSAVE features) was
improved in a recent patch. Unfortunately, this appears to have
introduced undefined behaviour for cases where ecx > 30, as the result
of (1 << idx) is undefined if idx > 30.
Per Intel SDM section 13.2, the behaviour for ecx values
