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| author |   Chuhong Yuan <hslester96@gmail.com> | 2019-08-08 15:18:26 +0800 |
|---|---|---|
| committer |   Vasily Gorbik <gor@linux.ibm.com> | 2019-08-21 12:41:43 +0200 |
| commit | 40e90656c13587c0826e8afeef3cebe585db2d2c (patch) | |
| tree | 0d733b4321ccc910b63fcb1990dd30f52725a242 /arch/s390/mm/gmap.c | |
| parent | s390/extmem: use refcount_t for refcount (diff) | |
| download | linux-dev-40e90656c13587c0826e8afeef3cebe585db2d2c.tar.xz linux-dev-40e90656c13587c0826e8afeef3cebe585db2d2c.zip | |
s390/mm: 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/20190808071826.6649-1-hslester96@gmail.com
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/mm/gmap.c')
| -rw-r--r-- | arch/s390/mm/gmap.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 1e668b95e0c6..3770f12d9252 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -67,7 +67,7 @@ static struct gmap *gmap_alloc(unsigned long limit) INIT_RADIX_TREE(&gmap->host_to_rmap, GFP_ATOMIC); spin_lock_init(&gmap->guest_table_lock); spin_lock_init(&gmap->shadow_lock); - atomic_set(&gmap->ref_count, 1); + refcount_set(&gmap->ref_count, 1); page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER); if (!page) goto out_free; @@ -214,7 +214,7 @@ static void gmap_free(struct gmap *gmap) */ struct gmap *gmap_get(struct gmap *gmap) { - atomic_inc(&gmap->ref_count); + refcount_inc(&gmap->ref_count); return gmap; } EXPORT_SYMBOL_GPL(gmap_get); @@ -227,7 +227,7 @@ EXPORT_SYMBOL_GPL(gmap_get); */ void gmap_put(struct gmap *gmap) { - if (atomic_dec_return(&gmap->ref_count) == 0) + if (refcount_dec_and_test(&gmap->ref_count)) gmap_free(gmap); } EXPORT_SYMBOL_GPL(gmap_put); @@ -1594,7 +1594,7 @@ static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce, continue; if (!sg->initialized) return ERR_PTR(-EAGAIN); - atomic_inc(&sg->ref_count); + refcount_inc(&sg->ref_count); return sg; } return NULL; @@ -1682,7 +1682,7 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce, } } } - atomic_set(&new->ref_count, 2); + refcount_set(&new->ref_count, 2); list_add(&new->list, &parent->children); if (asce & _ASCE_REAL_SPACE) { /* nothing to protect, return right away */ |