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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2016-12-28 10:33:48 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-05 12:40:26 (GMT) |
| commit | 0e9867b7113c56b367f2e753cd411cf7cef0d2ec (patch) | |
| tree | b0a67b38e4ef9cd65428dac0a092712a841c9306 /drivers/usb | |
| parent | 9d00195bc0afa0252b9cdb157eb4ed1e13631bc6 (diff) | |
| download | linux-0e9867b7113c56b367f2e753cd411cf7cef0d2ec.tar.xz | |
s390/ctl_reg: make __ctl_load a full memory barrier
[ Upstream commit e991c24d68b8c0ba297eeb7af80b1e398e98c33f ]
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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
0 files changed, 0 insertions, 0 deletions