linux/arch/s390/include
Heiko Carstens e991c24d68 s390/ctl_reg: make __ctl_load a full memory barrier
We have quite a lot of code that depends on the order of the
__ctl_load inline assemby and subsequent memory accesses, like
e.g. disabling lowcore protection and the writing to lowcore.

Since the __ctl_load macro does not have memory barrier semantics, nor
any other dependencies the compiler is, theoretically, free to shuffle
code around. Or in other words: storing to lowcore could happen before
lowcore protection is disabled.

In order to avoid this class of potential bugs simply add a full
memory barrier to the __ctl_load macro.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-01-16 07:27:48 +01:00
..
asm s390/ctl_reg: make __ctl_load a full memory barrier 2017-01-16 07:27:48 +01:00
uapi/asm s390/zcrypt: Introduce new zcrypt device status API 2016-12-14 16:33:38 +01:00