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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2016-12-28 11:33:48 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-05 14:37:20 +0200 |
| commit | 5416a88c2fef39a9d75ef59057625a2002959dff (patch) | |
| tree | acd1576197fae4de68e598b0fbc563566973e361 /scripts/gdb/linux/tasks.py | |
| parent | 9a536d5872460def17d2279f81a4a4d09e36f620 (diff) | |
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 'scripts/gdb/linux/tasks.py')
0 files changed, 0 insertions, 0 deletions