ipc: unify the syscalls code
This patch introduces a change into the sys_msgget(), sys_semget() and sys_shmget() routines: they now share a common code, which is better for maintainability. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nadia Derbey
Linus Torvalds
Родитель
7ca7e564e0
Коммит
7748dbfaa0
61
ipc/msg.c
61
ipc/msg.c
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@ -81,7 +81,7 @@ static struct ipc_ids init_msg_ids;
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ipc_buildid(&msg_ids(ns), id, seq)
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static void freeque(struct ipc_namespace *, struct msg_queue *);
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static int newque (struct ipc_namespace *ns, key_t key, int msgflg);
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static int newque(struct ipc_namespace *, struct ipc_params *);
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#ifdef CONFIG_PROC_FS
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static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
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#endif
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@ -144,10 +144,12 @@ static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
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ipc_rmid(&msg_ids(ns), &s->q_perm);
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}
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static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
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static int newque(struct ipc_namespace *ns, struct ipc_params *params)
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{
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struct msg_queue *msq;
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int id, retval;
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key_t key = params->key;
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int msgflg = params->flg;
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msq = ipc_rcu_alloc(sizeof(*msq));
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if (!msq)
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@ -264,56 +266,27 @@ static void freeque(struct ipc_namespace *ns, struct msg_queue *msq)
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ipc_rcu_putref(msq);
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}
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static inline int msg_security(void *msq, int msgflg)
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{
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return security_msg_queue_associate((struct msg_queue *) msq, msgflg);
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}
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asmlinkage long sys_msgget(key_t key, int msgflg)
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{
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struct msg_queue *msq;
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int ret;
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struct ipc_namespace *ns;
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struct ipc_ops msg_ops;
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struct ipc_params msg_params;
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ns = current->nsproxy->ipc_ns;
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ret = idr_pre_get(&msg_ids(ns).ipcs_idr, GFP_KERNEL);
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msg_ops.getnew = newque;
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msg_ops.associate = msg_security;
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msg_ops.more_checks = NULL;
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if (key == IPC_PRIVATE) {
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if (!ret)
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ret = -ENOMEM;
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else {
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mutex_lock(&msg_ids(ns).mutex);
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ret = newque(ns, key, msgflg);
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mutex_unlock(&msg_ids(ns).mutex);
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}
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} else {
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mutex_lock(&msg_ids(ns).mutex);
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msq = (struct msg_queue *) ipc_findkey(&msg_ids(ns), key);
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if (msq == NULL) {
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/* key not used */
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if (!(msgflg & IPC_CREAT))
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ret = -ENOENT;
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else if (!ret)
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ret = -ENOMEM;
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else
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ret = newque(ns, key, msgflg);
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} else {
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/* msq has been locked by ipc_findkey() */
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msg_params.key = key;
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msg_params.flg = msgflg;
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if (msgflg & IPC_CREAT && msgflg & IPC_EXCL)
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ret = -EEXIST;
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else {
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if (ipcperms(&msq->q_perm, msgflg))
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ret = -EACCES;
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else {
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ret = security_msg_queue_associate(
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msq, msgflg);
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if (!ret)
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ret = msq->q_perm.id;
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}
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}
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msg_unlock(msq);
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}
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mutex_unlock(&msg_ids(ns).mutex);
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}
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return ret;
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return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
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}
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static inline unsigned long
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76
ipc/sem.c
76
ipc/sem.c
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@ -97,7 +97,7 @@
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static struct ipc_ids init_sem_ids;
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static int newary(struct ipc_namespace *, key_t, int, int);
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static int newary(struct ipc_namespace *, struct ipc_params *);
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static void freeary(struct ipc_namespace *, struct sem_array *);
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#ifdef CONFIG_PROC_FS
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static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
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@ -214,12 +214,15 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
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*/
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#define IN_WAKEUP 1
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static int newary (struct ipc_namespace *ns, key_t key, int nsems, int semflg)
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static int newary(struct ipc_namespace *ns, struct ipc_params *params)
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{
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int id;
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int retval;
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struct sem_array *sma;
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int size;
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key_t key = params->key;
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int nsems = params->u.nsems;
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int semflg = params->flg;
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if (!nsems)
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return -EINVAL;
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@ -263,61 +266,40 @@ static int newary (struct ipc_namespace *ns, key_t key, int nsems, int semflg)
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return sma->sem_perm.id;
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}
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asmlinkage long sys_semget (key_t key, int nsems, int semflg)
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static inline int sem_security(void *sma, int semflg)
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{
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return security_sem_associate((struct sem_array *) sma, semflg);
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}
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static inline int sem_more_checks(void *sma, struct ipc_params *params)
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{
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if (params->u.nsems > ((struct sem_array *)sma)->sem_nsems)
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return -EINVAL;
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return 0;
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}
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asmlinkage long sys_semget(key_t key, int nsems, int semflg)
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{
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int err;
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struct sem_array *sma;
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struct ipc_namespace *ns;
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struct ipc_ops sem_ops;
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struct ipc_params sem_params;
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ns = current->nsproxy->ipc_ns;
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if (nsems < 0 || nsems > ns->sc_semmsl)
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return -EINVAL;
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err = idr_pre_get(&sem_ids(ns).ipcs_idr, GFP_KERNEL);
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sem_ops.getnew = newary;
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sem_ops.associate = sem_security;
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sem_ops.more_checks = sem_more_checks;
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if (key == IPC_PRIVATE) {
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if (!err)
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err = -ENOMEM;
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else {
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mutex_lock(&sem_ids(ns).mutex);
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err = newary(ns, key, nsems, semflg);
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mutex_unlock(&sem_ids(ns).mutex);
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}
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} else {
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mutex_lock(&sem_ids(ns).mutex);
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sma = (struct sem_array *) ipc_findkey(&sem_ids(ns), key);
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if (sma == NULL) {
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/* key not used */
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if (!(semflg & IPC_CREAT))
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err = -ENOENT;
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else if (!err)
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err = -ENOMEM;
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else
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err = newary(ns, key, nsems, semflg);
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} else {
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/* sma has been locked by ipc_findkey() */
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sem_params.key = key;
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sem_params.flg = semflg;
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sem_params.u.nsems = nsems;
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if (semflg & IPC_CREAT && semflg & IPC_EXCL)
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err = -EEXIST;
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else {
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if (nsems > sma->sem_nsems)
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err = -EINVAL;
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else if (ipcperms(&sma->sem_perm, semflg))
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err = -EACCES;
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else {
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err = security_sem_associate(sma,
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semflg);
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if (!err)
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err = sma->sem_perm.id;
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}
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}
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sem_unlock(sma);
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}
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mutex_unlock(&sem_ids(ns).mutex);
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}
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return err;
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return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params);
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}
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/* Manage the doubly linked list sma->sem_pending as a FIFO:
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73
ipc/shm.c
73
ipc/shm.c
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@ -68,8 +68,7 @@ static struct ipc_ids init_shm_ids;
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#define shm_buildid(ns, id, seq) \
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ipc_buildid(&shm_ids(ns), id, seq)
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static int newseg (struct ipc_namespace *ns, key_t key,
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int shmflg, size_t size);
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static int newseg(struct ipc_namespace *, struct ipc_params *);
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static void shm_open(struct vm_area_struct *vma);
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static void shm_close(struct vm_area_struct *vma);
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static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
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@ -341,8 +340,11 @@ static struct vm_operations_struct shm_vm_ops = {
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#endif
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};
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static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
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static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
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{
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key_t key = params->key;
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int shmflg = params->flg;
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size_t size = params->u.size;
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int error;
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struct shmid_kernel *shp;
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int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
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@ -423,57 +425,36 @@ no_file:
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return error;
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}
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static inline int shm_security(void *shp, int shmflg)
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{
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return security_shm_associate((struct shmid_kernel *) shp, shmflg);
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}
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static inline int shm_more_checks(void *shp, struct ipc_params *params)
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{
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if (((struct shmid_kernel *)shp)->shm_segsz < params->u.size)
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return -EINVAL;
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return 0;
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}
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asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
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{
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struct shmid_kernel *shp;
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int err;
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struct ipc_namespace *ns;
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struct ipc_ops shm_ops;
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struct ipc_params shm_params;
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ns = current->nsproxy->ipc_ns;
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err = idr_pre_get(&shm_ids(ns).ipcs_idr, GFP_KERNEL);
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shm_ops.getnew = newseg;
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shm_ops.associate = shm_security;
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shm_ops.more_checks = shm_more_checks;
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if (key == IPC_PRIVATE) {
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if (!err)
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err = -ENOMEM;
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else {
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mutex_lock(&shm_ids(ns).mutex);
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err = newseg(ns, key, shmflg, size);
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mutex_unlock(&shm_ids(ns).mutex);
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}
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} else {
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mutex_lock(&shm_ids(ns).mutex);
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shp = (struct shmid_kernel *) ipc_findkey(&shm_ids(ns), key);
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if (shp == NULL) {
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if (!(shmflg & IPC_CREAT))
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err = -ENOENT;
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else if (!err)
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err = -ENOMEM;
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else
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err = newseg(ns, key, shmflg, size);
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} else {
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/* shp has been locked by ipc_findkey() */
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shm_params.key = key;
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shm_params.flg = shmflg;
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shm_params.u.size = size;
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if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL))
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err = -EEXIST;
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else {
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if (shp->shm_segsz < size)
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err = -EINVAL;
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else if (ipcperms(&shp->shm_perm, shmflg))
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err = -EACCES;
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else {
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err = security_shm_associate(shp,
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shmflg);
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if (!err)
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err = shp->shm_perm.id;
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}
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}
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shm_unlock(shp);
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}
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mutex_unlock(&shm_ids(ns).mutex);
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}
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return err;
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return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
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}
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static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
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101
ipc/util.c
101
ipc/util.c
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@ -197,7 +197,7 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
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* If key is found ipc contains its ipc structure
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*/
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struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
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static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
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{
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struct kern_ipc_perm *ipc;
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int next_id;
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@ -300,6 +300,105 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
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return id;
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}
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/**
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* ipcget_new - create a new ipc object
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* @ns: namespace
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* @ids: identifer set
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* @ops: the actual creation routine to call
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* @params: its parameters
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*
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* This routine is called sys_msgget, sys_semget() and sys_shmget() when
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* the key is IPC_PRIVATE
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*/
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int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
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struct ipc_ops *ops, struct ipc_params *params)
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{
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int err;
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err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
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if (!err)
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return -ENOMEM;
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mutex_lock(&ids->mutex);
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err = ops->getnew(ns, params);
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mutex_unlock(&ids->mutex);
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return err;
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}
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/**
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* ipc_check_perms - check security and permissions for an IPC
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* @ipcp: ipc permission set
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* @ids: identifer set
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* @ops: the actual security routine to call
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* @params: its parameters
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*/
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static int ipc_check_perms(struct kern_ipc_perm *ipcp, struct ipc_ops *ops,
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struct ipc_params *params)
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{
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int err;
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if (ipcperms(ipcp, params->flg))
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err = -EACCES;
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else {
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err = ops->associate(ipcp, params->flg);
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if (!err)
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err = ipcp->id;
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}
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return err;
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}
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/**
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* ipcget_public - get an ipc object or create a new one
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* @ns: namespace
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* @ids: identifer set
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* @ops: the actual creation routine to call
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* @params: its parameters
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*
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* This routine is called sys_msgget, sys_semget() and sys_shmget() when
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* the key is not IPC_PRIVATE
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*/
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int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
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struct ipc_ops *ops, struct ipc_params *params)
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{
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struct kern_ipc_perm *ipcp;
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int flg = params->flg;
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int err;
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err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
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mutex_lock(&ids->mutex);
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ipcp = ipc_findkey(ids, params->key);
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if (ipcp == NULL) {
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/* key not used */
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if (!(flg & IPC_CREAT))
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err = -ENOENT;
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else if (!err)
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err = -ENOMEM;
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else
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err = ops->getnew(ns, params);
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} else {
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/* ipc object has been locked by ipc_findkey() */
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if (flg & IPC_CREAT && flg & IPC_EXCL)
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err = -EEXIST;
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else {
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err = 0;
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if (ops->more_checks)
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err = ops->more_checks(ipcp, params);
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if (!err)
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err = ipc_check_perms(ipcp, ops, params);
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}
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ipc_unlock(ipcp);
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}
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mutex_unlock(&ids->mutex);
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return err;
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}
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/**
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* ipc_rmid - remove an IPC identifier
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* @ids: identifier set
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|
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43
ipc/util.h
43
ipc/util.h
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@ -35,6 +35,35 @@ struct ipc_ids {
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struct idr ipcs_idr;
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};
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/*
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* Structure that holds the parameters needed by the ipc operations
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* (see after)
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*/
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struct ipc_params {
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key_t key;
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int flg;
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union {
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size_t size; /* for shared memories */
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int nsems; /* for semaphores */
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} u; /* holds the getnew() specific param */
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};
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/*
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* Structure that holds some ipc operations. This structure is used to unify
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* the calls to sys_msgget(), sys_semget(), sys_shmget()
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* . routine to call to create a new ipc object. Can be one of newque,
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* newary, newseg
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* . routine to call to call to check permissions for a new ipc object.
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* Can be one of security_msg_associate, security_sem_associate,
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* security_shm_associate
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* . routine to call for an extra check if needed
|
||||
*/
|
||||
struct ipc_ops {
|
||||
int (*getnew) (struct ipc_namespace *, struct ipc_params *);
|
||||
int (*associate) (void *, int);
|
||||
int (*more_checks) (void *, struct ipc_params *);
|
||||
};
|
||||
|
||||
struct seq_file;
|
||||
|
||||
void ipc_init_ids(struct ipc_ids *);
|
||||
|
|
@ -50,7 +79,6 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
|
|||
#define IPC_SHM_IDS 2
|
||||
|
||||
/* must be called with ids->mutex acquired.*/
|
||||
struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key);
|
||||
int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
|
||||
int ipc_get_maxid(struct ipc_ids *);
|
||||
|
||||
|
|
@ -95,5 +123,18 @@ int ipc_parse_version (int *cmd);
|
|||
extern void free_msg(struct msg_msg *msg);
|
||||
extern struct msg_msg *load_msg(const void __user *src, int len);
|
||||
extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
|
||||
extern int ipcget_new(struct ipc_namespace *, struct ipc_ids *,
|
||||
struct ipc_ops *, struct ipc_params *);
|
||||
extern int ipcget_public(struct ipc_namespace *, struct ipc_ids *,
|
||||
struct ipc_ops *, struct ipc_params *);
|
||||
|
||||
static inline int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
|
||||
struct ipc_ops *ops, struct ipc_params *params)
|
||||
{
|
||||
if (params->key == IPC_PRIVATE)
|
||||
return ipcget_new(ns, ids, ops, params);
|
||||
else
|
||||
return ipcget_public(ns, ids, ops, params);
|
||||
}
|
||||
|
||||
#endif
|
||||
|
|
|
|||
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