Re: [PATCH v12 07/22] selftests/vm: fixed bugs in pkey_disable_clear()

From: Thiago Jung Bauermann
Date: Wed Mar 28 2018 - 16:47:31 EST



Dave Hansen <dave.hansen@xxxxxxxxx> writes:

> On 02/21/2018 05:55 PM, Ram Pai wrote:
>> --- a/tools/testing/selftests/vm/protection_keys.c
>> +++ b/tools/testing/selftests/vm/protection_keys.c
>> @@ -461,7 +461,7 @@ void pkey_disable_clear(int pkey, int flags)
>> pkey, pkey, pkey_rights);
>> pkey_assert(pkey_rights >= 0);
>>
>> - pkey_rights |= flags;
>> + pkey_rights &= ~flags;
>>
>> ret = pkey_set(pkey, pkey_rights, 0);
>> /* pkey_reg and flags have the same format */
>> @@ -475,7 +475,7 @@ void pkey_disable_clear(int pkey, int flags)
>> dprintf1("%s(%d) pkey_reg: 0x%016lx\n", __func__,
>> pkey, rdpkey_reg());
>> if (flags)
>> - assert(rdpkey_reg() > orig_pkey_reg);
>> + assert(rdpkey_reg() < orig_pkey_reg);
>> }
>>
>> void pkey_write_allow(int pkey)
>
> This seems so horribly wrong that I wonder how it worked in the first
> place. Any idea?

The code simply wasn't used. pkey_disable_clear() is called by
pkey_write_allow() and pkey_access_allow(), but before this patch series
nothing called either of these functions.


--
Thiago Jung Bauermann
IBM Linux Technology Center