s390/mm: fix local TLB flushing vs. detach of an mm address space

Browse source

The local TLB flushing code keeps an additional mask in the mm.context,
the cpu_attach_mask. At the time a global flush of an address space is
done the cpu_attach_mask is copied to the mm_cpumask in order to avoid
future global flushes in case the mm is used by a single CPU only after
the flush.

Trouble is that the reset of the mm_cpumask is racy against the detach
of an mm address space by switch_mm. The current order is first the
global TLB flush and then the copy of the cpu_attach_mask to the
mm_cpumask. The order needs to be the other way around.

Cc: <stable@vger.kernel.org>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

...

This commit is contained in:

Martin Schwidefsky 2017-08-16 14:10:01 +02:00

parent 46fde9a9d2

commit b3e5dc45fd

2 changed files with 7 additions and 23 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

4

arch/s390/include/asm/mmu_context.h

View file

26

arch/s390/include/asm/tlbflush.h

View file