Re: x86/fpu/xsave: protection key test failures

From: Dave Hansen
Date: Tue May 25 2021 - 20:20:40 EST


On 5/25/21 5:03 PM, Babu Moger wrote:
>> What values do PKRU and the shadow have when the test fails? Is PKRU 0?
> It goes back to default value 0x55555554. The test is expecting it to be
> 0. Printed them below.
>
> test_ptrace_of_child()::1346, pkey_reg: 0x0000000055555554 shadow:
> 0000000000000000
> protection_keys_64: pkey-helpers.h:127: _read_pkey_reg: Assertion
> `pkey_reg == shadow_pkey_reg' failed.

That's backwards (shadow vs pkru) from what I was expecting.

Can you turn on all the debuging?

Just compile with -DDEBUG_LEVEL=5