diff options
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/msg.c | 19 | ||||
| -rw-r--r-- | ipc/sem.c | 34 | ||||
| -rw-r--r-- | ipc/shm.c | 18 | ||||
| -rw-r--r-- | ipc/util.c | 35 | ||||
| -rw-r--r-- | ipc/util.h | 18 |
5 files changed, 63 insertions, 61 deletions
diff --git a/ipc/msg.c b/ipc/msg.c index 104926dc72be..0ed7dae7d4e8 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -97,8 +97,8 @@ static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) static void msg_rcu_free(struct rcu_head *head) { - struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu); - struct msg_queue *msq = ipc_rcu_to_struct(p); + struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu); + struct msg_queue *msq = container_of(p, struct msg_queue, q_perm); security_msg_queue_free(msq); ipc_rcu_free(head); @@ -118,7 +118,10 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params) key_t key = params->key; int msgflg = params->flg; - msq = ipc_rcu_alloc(sizeof(*msq)); + BUILD_BUG_ON(offsetof(struct msg_queue, q_perm) != 0); + + msq = container_of(ipc_rcu_alloc(sizeof(*msq)), struct msg_queue, + q_perm); if (!msq) return -ENOMEM; @@ -128,7 +131,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params) msq->q_perm.security = NULL; retval = security_msg_queue_alloc(msq); if (retval) { - ipc_rcu_putref(msq, ipc_rcu_free); + ipc_rcu_putref(&msq->q_perm, ipc_rcu_free); return retval; } @@ -144,7 +147,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params) /* ipc_addid() locks msq upon success. */ id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); if (id < 0) { - ipc_rcu_putref(msq, msg_rcu_free); + ipc_rcu_putref(&msq->q_perm, msg_rcu_free); return id; } @@ -249,7 +252,7 @@ static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) free_msg(msg); } atomic_sub(msq->q_cbytes, &ns->msg_bytes); - ipc_rcu_putref(msq, msg_rcu_free); + ipc_rcu_putref(&msq->q_perm, msg_rcu_free); } /* @@ -688,7 +691,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext, /* enqueue the sender and prepare to block */ ss_add(msq, &s, msgsz); - if (!ipc_rcu_getref(msq)) { + if (!ipc_rcu_getref(&msq->q_perm)) { err = -EIDRM; goto out_unlock0; } @@ -700,7 +703,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext, rcu_read_lock(); ipc_lock_object(&msq->q_perm); - ipc_rcu_putref(msq, msg_rcu_free); + ipc_rcu_putref(&msq->q_perm, msg_rcu_free); /* raced with RMID? */ if (!ipc_valid_object(&msq->q_perm)) { err = -EIDRM; diff --git a/ipc/sem.c b/ipc/sem.c index fff8337ebab3..bdff6d93d2c7 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -260,8 +260,8 @@ 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); + struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu); + struct sem_array *sma = container_of(p, struct sem_array, sem_perm); security_sem_free(sma); ipc_rcu_free(head); @@ -438,7 +438,7 @@ 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, sem_rcu_free); + ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); } static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s) @@ -469,20 +469,20 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params) if (ns->used_sems + nsems > ns->sc_semmns) return -ENOSPC; + BUILD_BUG_ON(offsetof(struct sem_array, sem_perm) != 0); + size = sizeof(*sma) + nsems * sizeof(sma->sems[0]); - sma = ipc_rcu_alloc(size); + sma = container_of(ipc_rcu_alloc(size), struct sem_array, sem_perm); if (!sma) return -ENOMEM; - memset(sma, 0, size); - sma->sem_perm.mode = (semflg & S_IRWXUGO); sma->sem_perm.key = key; sma->sem_perm.security = NULL; retval = security_sem_alloc(sma); if (retval) { - ipc_rcu_putref(sma, ipc_rcu_free); + ipc_rcu_putref(&sma->sem_perm, ipc_rcu_free); return retval; } @@ -502,7 +502,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params) id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni); if (id < 0) { - ipc_rcu_putref(sma, sem_rcu_free); + ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); return id; } ns->used_sems += nsems; @@ -1122,7 +1122,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) wake_up_q(&wake_q); ns->used_sems -= sma->sem_nsems; - ipc_rcu_putref(sma, sem_rcu_free); + ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); } static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version) @@ -1362,7 +1362,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum, goto out_unlock; } if (nsems > SEMMSL_FAST) { - if (!ipc_rcu_getref(sma)) { + if (!ipc_rcu_getref(&sma->sem_perm)) { err = -EIDRM; goto out_unlock; } @@ -1370,7 +1370,7 @@ 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) { - ipc_rcu_putref(sma, sem_rcu_free); + ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); return -ENOMEM; } @@ -1395,7 +1395,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum, int i; struct sem_undo *un; - if (!ipc_rcu_getref(sma)) { + if (!ipc_rcu_getref(&sma->sem_perm)) { err = -EIDRM; goto out_rcu_wakeup; } @@ -1404,20 +1404,20 @@ 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) { - ipc_rcu_putref(sma, sem_rcu_free); + ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); return -ENOMEM; } } if (copy_from_user(sem_io, p, nsems*sizeof(ushort))) { - ipc_rcu_putref(sma, sem_rcu_free); + ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); err = -EFAULT; goto out_free; } for (i = 0; i < nsems; i++) { if (sem_io[i] > SEMVMX) { - ipc_rcu_putref(sma, sem_rcu_free); + ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); err = -ERANGE; goto out_free; } @@ -1699,7 +1699,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid) } nsems = sma->sem_nsems; - if (!ipc_rcu_getref(sma)) { + if (!ipc_rcu_getref(&sma->sem_perm)) { rcu_read_unlock(); un = ERR_PTR(-EIDRM); goto out; @@ -1709,7 +1709,7 @@ 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) { - ipc_rcu_putref(sma, sem_rcu_free); + ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); return ERR_PTR(-ENOMEM); } diff --git a/ipc/shm.c b/ipc/shm.c index f45c7959b264..5ef6d31a52c5 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -174,9 +174,10 @@ static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp) static void shm_rcu_free(struct rcu_head *head) { - struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu); - struct shmid_kernel *shp = ipc_rcu_to_struct(p); - + struct kern_ipc_perm *ptr = container_of(head, struct kern_ipc_perm, + rcu); + struct shmid_kernel *shp = container_of(ptr, struct shmid_kernel, + shm_perm); security_shm_free(shp); ipc_rcu_free(head); } @@ -241,7 +242,7 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) user_shm_unlock(i_size_read(file_inode(shm_file)), shp->mlock_user); fput(shm_file); - ipc_rcu_putref(shp, shm_rcu_free); + ipc_rcu_putref(&shp->shm_perm, shm_rcu_free); } /* @@ -542,7 +543,10 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) ns->shm_tot + numpages > ns->shm_ctlall) return -ENOSPC; - shp = ipc_rcu_alloc(sizeof(*shp)); + BUILD_BUG_ON(offsetof(struct shmid_kernel, shm_perm) != 0); + + shp = container_of(ipc_rcu_alloc(sizeof(*shp)), struct shmid_kernel, + shm_perm); if (!shp) return -ENOMEM; @@ -553,7 +557,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) shp->shm_perm.security = NULL; error = security_shm_alloc(shp); if (error) { - ipc_rcu_putref(shp, ipc_rcu_free); + ipc_rcu_putref(&shp->shm_perm, ipc_rcu_free); return error; } @@ -624,7 +628,7 @@ no_id: user_shm_unlock(size, shp->mlock_user); fput(file); no_file: - ipc_rcu_putref(shp, shm_rcu_free); + ipc_rcu_putref(&shp->shm_perm, shm_rcu_free); return error; } diff --git a/ipc/util.c b/ipc/util.c index caec7b1bfaa3..5d1ff1035efe 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -418,46 +418,45 @@ void ipc_free(void *ptr) } /** - * ipc_rcu_alloc - allocate ipc and rcu space + * ipc_rcu_alloc - allocate ipc space * @size: size desired * - * Allocate memory for the rcu header structure + the object. - * Returns the pointer to the object or NULL upon failure. + * Allocate memory for an ipc object. + * The first member must be struct kern_ipc_perm. */ -void *ipc_rcu_alloc(int size) +struct kern_ipc_perm *ipc_rcu_alloc(int size) { /* * We prepend the allocation with the rcu struct */ - struct ipc_rcu *out = ipc_alloc(sizeof(struct ipc_rcu) + size); + struct kern_ipc_perm *out = ipc_alloc(size); if (unlikely(!out)) return NULL; + + memset(out, 0, size); atomic_set(&out->refcount, 1); - return out + 1; + return out; } -int ipc_rcu_getref(void *ptr) +int ipc_rcu_getref(struct kern_ipc_perm *ptr) { - struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1; - - return atomic_inc_not_zero(&p->refcount); + return atomic_inc_not_zero(&ptr->refcount); } -void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head)) +void ipc_rcu_putref(struct kern_ipc_perm *ptr, + void (*func)(struct rcu_head *head)) { - struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1; - - if (!atomic_dec_and_test(&p->refcount)) + if (!atomic_dec_and_test(&ptr->refcount)) return; - call_rcu(&p->rcu, func); + call_rcu(&ptr->rcu, func); } -void ipc_rcu_free(struct rcu_head *head) +void ipc_rcu_free(struct rcu_head *h) { - struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu); + struct kern_ipc_perm *ptr = container_of(h, struct kern_ipc_perm, rcu); - kvfree(p); + kvfree(ptr); } /** diff --git a/ipc/util.h b/ipc/util.h index 60ddccca464d..09d0f918c3e2 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -47,13 +47,6 @@ static inline void msg_exit_ns(struct ipc_namespace *ns) { } static inline void shm_exit_ns(struct ipc_namespace *ns) { } #endif -struct ipc_rcu { - struct rcu_head rcu; - atomic_t refcount; -} ____cacheline_aligned_in_smp; - -#define ipc_rcu_to_struct(p) ((void *)(p+1)) - /* * Structure that holds the parameters needed by the ipc operations * (see after) @@ -125,11 +118,14 @@ void ipc_free(void *ptr); * Objects are reference counted, they start with reference count 1. * getref increases the refcount, the putref call that reduces the recount * to 0 schedules the rcu destruction. Caller must guarantee locking. + * + * struct kern_ipc_perm must be the first member in the allocated structure. */ -void *ipc_rcu_alloc(int size); -int ipc_rcu_getref(void *ptr); -void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head)); -void ipc_rcu_free(struct rcu_head *head); +struct kern_ipc_perm *ipc_rcu_alloc(int size); +int ipc_rcu_getref(struct kern_ipc_perm *ptr); +void ipc_rcu_putref(struct kern_ipc_perm *ptr, + void (*func)(struct rcu_head *head)); +void ipc_rcu_free(struct rcu_head *h); struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int); struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id); |