2016-07-04 22:58 GMT+03:00 Andi Kleen <a...@firstfloor.org>:
> Andi Kleen <a...@firstfloor.org> writes:
>
> PING!
>
>> From: Andi Kleen <a...@linux.intel.com>
>>
>> I have a Skylake system with MPX in the CPU, but MPX is disabled
>> in the kernel configuration.
>>
>> This makes all the MPX tests fail because they assume if MPX
>> is in CPUID it works
>>
>> Check the output of XGETBV too to detect non MPX kernels.
The patch is OK for trunk and GCC 6 branch
Thanks,
Ilya
>>
>> gcc/testsuite/:
>>
>> 2016-06-25 Andi Kleen <a...@linux.intel.com>
>>
>> * gcc.target/i386/mpx/mpx-check.h: Check XGETBV output
>> if kernel supports MPX.
>> ---
>> gcc/testsuite/gcc.target/i386/mpx/mpx-check.h | 12 +++++++++++-
>> 1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/gcc/testsuite/gcc.target/i386/mpx/mpx-check.h
>> b/gcc/testsuite/gcc.target/i386/mpx/mpx-check.h
>> index 3afa460..73aa01f 100644
>> --- a/gcc/testsuite/gcc.target/i386/mpx/mpx-check.h
>> +++ b/gcc/testsuite/gcc.target/i386/mpx/mpx-check.h
>> @@ -16,6 +16,16 @@ mpx_test (int, const char **);
>>
>> #define DEBUG
>>
>> +#define XSTATE_BNDREGS (1 << 3)
>> +
>> +/* This should be an intrinsic, but isn't. */
>> +static int xgetbv (unsigned x)
>> +{
>> + unsigned eax, edx;
>> + asm ("xgetbv" : "=a" (eax), "=d" (edx) : "c" (x));
>> + return eax;
>> +}
>> +
>> int
>> main (int argc, const char **argv)
>> {
>> @@ -27,7 +37,7 @@ main (int argc, const char **argv)
>> __cpuid_count (7, 0, eax, ebx, ecx, edx);
>>
>> /* Run MPX test only if host has MPX support. */
>> - if (ebx & bit_MPX)
>> + if ((ebx & bit_MPX) && (xgetbv (0) & XSTATE_BNDREGS))
>> mpx_test (argc, argv);
>> else
>> {
>
> --
> a...@linux.intel.com -- Speaking for myself only
