Heiko Carstens 5f5c1e6833 s390/mem_detect: fix tprot() program check new psw handling
[ Upstream commit da9057576785aaab52e706e76c0475c85b77ec14 ]

The tprot() inline asm temporarily changes the program check new psw
to redirect a potential program check on the diag instruction.
Restoring of the program check new psw is done in C code behind the
inline asm.

This can be problematic, especially if the function is inlined, since
the compiler can reorder instructions in such a way that a different
instruction, which may result in a program check, might be executed
before the program check new psw has been restored.

To avoid such a scenario move restoring into the inline asm. For
consistency reasons move also saving of the original program check new
psw into the inline asm.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:10:45 +02:00
..
2019-05-02 13:54:11 +02:00
2019-09-17 14:04:43 -07:00
2017-11-24 15:37:24 +01:00
2020-02-28 17:22:28 +01:00