s390/extmem: use refcount_t for refcount
authorChuhong Yuan <hslester96@gmail.com>
Thu, 8 Aug 2019 07:18:17 +0000 (15:18 +0800)
committerVasily Gorbik <gor@linux.ibm.com>
Wed, 21 Aug 2019 10:41:43 +0000 (12:41 +0200)
commit3434caec5b70519ead87e7b66dbdc18e8dbaa506
treed1664307d7535e986df81f880aee8f9edb6fd685
parentc4c3772384bc93e3d1eccd88bd7f5d74de74e0d7
s390/extmem: use refcount_t for refcount

Reference counters are preferred to use refcount_t instead of
atomic_t.
This is because the implementation of refcount_t can prevent
overflows and detect possible use-after-free.
So convert atomic_t ref counters to refcount_t.

Link: http://lkml.kernel.org/r/20190808071817.6595-1-hslester96@gmail.com
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
arch/s390/mm/extmem.c