mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 02:39:48 +00:00
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>
This commit is contained in:
parent
3434caec5b
commit
40e90656c1
2 changed files with 8 additions and 6 deletions
|
@ -9,6 +9,8 @@
|
|||
#ifndef _ASM_S390_GMAP_H
|
||||
#define _ASM_S390_GMAP_H
|
||||
|
||||
#include <linux/refcount.h>
|
||||
|
||||
/* Generic bits for GMAP notification on DAT table entry changes. */
|
||||
#define GMAP_NOTIFY_SHADOW 0x2
|
||||
#define GMAP_NOTIFY_MPROT 0x1
|
||||
|
@ -46,7 +48,7 @@ struct gmap {
|
|||
struct radix_tree_root guest_to_host;
|
||||
struct radix_tree_root host_to_guest;
|
||||
spinlock_t guest_table_lock;
|
||||
atomic_t ref_count;
|
||||
refcount_t ref_count;
|
||||
unsigned long *table;
|
||||
unsigned long asce;
|
||||
unsigned long asce_end;
|
||||
|
|
|
@ -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 */
|
||||
|
|
Loading…
Reference in a new issue