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Diffstat (limited to 'security/selinux/ss/sidtab.h')
-rw-r--r--security/selinux/ss/sidtab.h19
1 files changed, 14 insertions, 5 deletions
diff --git a/security/selinux/ss/sidtab.h b/security/selinux/ss/sidtab.h
index bbd5c0d1f3bd..1f4763141aa1 100644
--- a/security/selinux/ss/sidtab.h
+++ b/security/selinux/ss/sidtab.h
@@ -40,8 +40,8 @@ union sidtab_entry_inner {
#define SIDTAB_LEAF_ENTRIES \
(SIDTAB_NODE_ALLOC_SIZE / sizeof(struct sidtab_entry_leaf))
-#define SIDTAB_MAX_BITS 31 /* limited to INT_MAX due to atomic_t range */
-#define SIDTAB_MAX (((u32)1 << SIDTAB_MAX_BITS) - 1)
+#define SIDTAB_MAX_BITS 32
+#define SIDTAB_MAX U32_MAX
/* ensure enough tree levels for SIDTAB_MAX entries */
#define SIDTAB_MAX_LEVEL \
DIV_ROUND_UP(SIDTAB_MAX_BITS - size_to_shift(SIDTAB_LEAF_ENTRIES), \
@@ -69,13 +69,22 @@ struct sidtab_convert_params {
#define SIDTAB_RCACHE_SIZE 3
struct sidtab {
+ /*
+ * lock-free read access only for as many items as a prior read of
+ * 'count'
+ */
union sidtab_entry_inner roots[SIDTAB_MAX_LEVEL + 1];
- atomic_t count;
+ /*
+ * access atomically via {READ|WRITE}_ONCE(); only increment under
+ * spinlock
+ */
+ u32 count;
+ /* access only under spinlock */
struct sidtab_convert_params *convert;
spinlock_t lock;
- /* reverse lookup cache */
- atomic_t rcache[SIDTAB_RCACHE_SIZE];
+ /* reverse lookup cache - access atomically via {READ|WRITE}_ONCE() */
+ u32 rcache[SIDTAB_RCACHE_SIZE];
/* index == SID - 1 (no entry for SECSID_NULL) */
struct sidtab_isid_entry isids[SECINITSID_NUM];