diff options
Diffstat (limited to 'security/selinux/ss/sidtab.h')
| -rw-r--r-- | security/selinux/ss/sidtab.h | 19 |
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]; |