diff options
Diffstat (limited to 'ipc/sem.c')
-rw-r--r-- | ipc/sem.c | 58 |
1 files changed, 30 insertions, 28 deletions
diff --git a/ipc/sem.c b/ipc/sem.c index 41088899783d..19c8b980d1fe 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -243,6 +243,15 @@ static void merge_queues(struct sem_array *sma) } } +static void sem_rcu_free(struct rcu_head *head) +{ + struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu); + struct sem_array *sma = ipc_rcu_to_struct(p); + + security_sem_free(sma); + ipc_rcu_free(head); +} + /* * If the request contains only one semaphore operation, and there are * no complex transactions pending, lock only the semaphore involved. @@ -322,7 +331,7 @@ static inline void sem_unlock(struct sem_array *sma, int locknum) } /* - * sem_lock_(check_) routines are called in the paths where the rw_mutex + * sem_lock_(check_) routines are called in the paths where the rwsem * is not held. * * The caller holds the RCU read lock. @@ -374,12 +383,7 @@ static inline struct sem_array *sem_obtain_object_check(struct ipc_namespace *ns static inline void sem_lock_and_putref(struct sem_array *sma) { sem_lock(sma, NULL, -1); - ipc_rcu_putref(sma); -} - -static inline void sem_putref(struct sem_array *sma) -{ - ipc_rcu_putref(sma); + ipc_rcu_putref(sma, ipc_rcu_free); } static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s) @@ -426,7 +430,7 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s) * @ns: namespace * @params: ptr to the structure that contains key, semflg and nsems * - * Called with sem_ids.rw_mutex held (as a writer) + * Called with sem_ids.rwsem held (as a writer) */ static int newary(struct ipc_namespace *ns, struct ipc_params *params) @@ -458,14 +462,13 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params) sma->sem_perm.security = NULL; retval = security_sem_alloc(sma); if (retval) { - ipc_rcu_putref(sma); + ipc_rcu_putref(sma, ipc_rcu_free); return retval; } id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni); if (id < 0) { - security_sem_free(sma); - ipc_rcu_putref(sma); + ipc_rcu_putref(sma, sem_rcu_free); return id; } ns->used_sems += nsems; @@ -492,7 +495,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params) /* - * Called with sem_ids.rw_mutex and ipcp locked. + * Called with sem_ids.rwsem and ipcp locked. */ static inline int sem_security(struct kern_ipc_perm *ipcp, int semflg) { @@ -503,7 +506,7 @@ static inline int sem_security(struct kern_ipc_perm *ipcp, int semflg) } /* - * Called with sem_ids.rw_mutex and ipcp locked. + * Called with sem_ids.rwsem and ipcp locked. */ static inline int sem_more_checks(struct kern_ipc_perm *ipcp, struct ipc_params *params) @@ -994,8 +997,8 @@ static int count_semzcnt (struct sem_array * sma, ushort semnum) return semzcnt; } -/* Free a semaphore set. freeary() is called with sem_ids.rw_mutex locked - * as a writer and the spinlock for this semaphore set hold. sem_ids.rw_mutex +/* Free a semaphore set. freeary() is called with sem_ids.rwsem locked + * as a writer and the spinlock for this semaphore set hold. sem_ids.rwsem * remains locked on exit. */ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) @@ -1047,8 +1050,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) wake_up_sem_queue_do(&tasks); ns->used_sems -= sma->sem_nsems; - security_sem_free(sma); - ipc_rcu_putref(sma); + ipc_rcu_putref(sma, sem_rcu_free); } static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version) @@ -1116,7 +1118,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, seminfo.semmnu = SEMMNU; seminfo.semmap = SEMMAP; seminfo.semume = SEMUME; - down_read(&sem_ids(ns).rw_mutex); + down_read(&sem_ids(ns).rwsem); if (cmd == SEM_INFO) { seminfo.semusz = sem_ids(ns).in_use; seminfo.semaem = ns->used_sems; @@ -1125,7 +1127,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, seminfo.semaem = SEMAEM; } max_id = ipc_get_maxid(&sem_ids(ns)); - up_read(&sem_ids(ns).rw_mutex); + up_read(&sem_ids(ns).rwsem); if (copy_to_user(p, &seminfo, sizeof(struct seminfo))) return -EFAULT; return (max_id < 0) ? 0: max_id; @@ -1292,7 +1294,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum, rcu_read_unlock(); sem_io = ipc_alloc(sizeof(ushort)*nsems); if(sem_io == NULL) { - sem_putref(sma); + ipc_rcu_putref(sma, ipc_rcu_free); return -ENOMEM; } @@ -1328,20 +1330,20 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum, if(nsems > SEMMSL_FAST) { sem_io = ipc_alloc(sizeof(ushort)*nsems); if(sem_io == NULL) { - sem_putref(sma); + ipc_rcu_putref(sma, ipc_rcu_free); return -ENOMEM; } } if (copy_from_user (sem_io, p, nsems*sizeof(ushort))) { - sem_putref(sma); + ipc_rcu_putref(sma, ipc_rcu_free); err = -EFAULT; goto out_free; } for (i = 0; i < nsems; i++) { if (sem_io[i] > SEMVMX) { - sem_putref(sma); + ipc_rcu_putref(sma, ipc_rcu_free); err = -ERANGE; goto out_free; } @@ -1431,9 +1433,9 @@ copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version) } /* - * This function handles some semctl commands which require the rw_mutex + * This function handles some semctl commands which require the rwsem * to be held in write mode. - * NOTE: no locks must be held, the rw_mutex is taken inside this function. + * NOTE: no locks must be held, the rwsem is taken inside this function. */ static int semctl_down(struct ipc_namespace *ns, int semid, int cmd, int version, void __user *p) @@ -1448,7 +1450,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid, return -EFAULT; } - down_write(&sem_ids(ns).rw_mutex); + down_write(&sem_ids(ns).rwsem); rcu_read_lock(); ipcp = ipcctl_pre_down_nolock(ns, &sem_ids(ns), semid, cmd, @@ -1487,7 +1489,7 @@ out_unlock0: out_unlock1: rcu_read_unlock(); out_up: - up_write(&sem_ids(ns).rw_mutex); + up_write(&sem_ids(ns).rwsem); return err; } @@ -1629,7 +1631,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid) /* step 2: allocate new undo structure */ new = kzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL); if (!new) { - sem_putref(sma); + ipc_rcu_putref(sma, ipc_rcu_free); return ERR_PTR(-ENOMEM); } |