diff options
| -rw-r--r-- | include/linux/user_namespace.h | 11 | ||||
| -rw-r--r-- | kernel/ucount.c | 16 |
2 files changed, 14 insertions, 13 deletions
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index ad4dbef92597..a0bb6d012137 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -8,6 +8,7 @@ #include <linux/rculist_nulls.h> #include <linux/sched.h> #include <linux/workqueue.h> +#include <linux/rcuref.h> #include <linux/rwsem.h> #include <linux/sysctl.h> #include <linux/err.h> @@ -120,7 +121,7 @@ struct ucounts { struct user_namespace *ns; kuid_t uid; struct rcu_head rcu; - atomic_t count; + rcuref_t count; atomic_long_t ucount[UCOUNT_COUNTS]; atomic_long_t rlimit[UCOUNT_RLIMIT_COUNTS]; }; @@ -133,9 +134,15 @@ void retire_userns_sysctls(struct user_namespace *ns); struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); void dec_ucount(struct ucounts *ucounts, enum ucount_type type); struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid); -struct ucounts * __must_check get_ucounts(struct ucounts *ucounts); void put_ucounts(struct ucounts *ucounts); +static inline struct ucounts * __must_check get_ucounts(struct ucounts *ucounts) +{ + if (rcuref_get(&ucounts->count)) + return ucounts; + return NULL; +} + static inline long get_rlimit_value(struct ucounts *ucounts, enum rlimit_type type) { return atomic_long_read(&ucounts->rlimit[type]); diff --git a/kernel/ucount.c b/kernel/ucount.c index b6abaf68cdcc..8686e329b8f2 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -11,7 +11,7 @@ struct ucounts init_ucounts = { .ns = &init_user_ns, .uid = GLOBAL_ROOT_UID, - .count = ATOMIC_INIT(1), + .count = RCUREF_INIT(1), }; #define UCOUNTS_HASHTABLE_BITS 10 @@ -138,7 +138,7 @@ static struct ucounts *find_ucounts(struct user_namespace *ns, kuid_t uid, guard(rcu)(); hlist_nulls_for_each_entry_rcu(ucounts, pos, hashent, node) { if (uid_eq(ucounts->uid, uid) && (ucounts->ns == ns)) { - if (atomic_inc_not_zero(&ucounts->count)) + if (rcuref_get(&ucounts->count)) return ucounts; } } @@ -154,13 +154,6 @@ static void hlist_add_ucounts(struct ucounts *ucounts) spin_unlock_irq(&ucounts_lock); } -struct ucounts *get_ucounts(struct ucounts *ucounts) -{ - if (atomic_inc_not_zero(&ucounts->count)) - return ucounts; - return NULL; -} - struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid) { struct hlist_nulls_head *hashent = ucounts_hashentry(ns, uid); @@ -176,7 +169,7 @@ struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid) new->ns = ns; new->uid = uid; - atomic_set(&new->count, 1); + rcuref_init(&new->count, 1); spin_lock_irq(&ucounts_lock); ucounts = find_ucounts(ns, uid, hashent); @@ -196,7 +189,8 @@ void put_ucounts(struct ucounts *ucounts) { unsigned long flags; - if (atomic_dec_and_lock_irqsave(&ucounts->count, &ucounts_lock, flags)) { + if (rcuref_put(&ucounts->count)) { + spin_lock_irqsave(&ucounts_lock, flags); hlist_nulls_del_rcu(&ucounts->node); spin_unlock_irqrestore(&ucounts_lock, flags); |