X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=ipc%2Fmsg.c;h=46585a05473eceb84f23c456e0f7dc96ab0bfbf6;hb=46f382d2b69d2221086b823f0dbc8f32c027cac2;hp=c2ee26f01055c0314a4386629946bb5ce3511055;hpb=7748dbfaa010b12d5fb9ddf80199534c565c6bce;p=safe%2Fjmp%2Flinux-2.6 diff --git a/ipc/msg.c b/ipc/msg.c index c2ee26f..46585a0 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -34,8 +34,9 @@ #include #include #include -#include +#include #include +#include #include #include @@ -66,77 +67,80 @@ struct msg_sender { #define SEARCH_NOTEQUAL 3 #define SEARCH_LESSEQUAL 4 -static atomic_t msg_bytes = ATOMIC_INIT(0); -static atomic_t msg_hdrs = ATOMIC_INIT(0); +#define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS]) -static struct ipc_ids init_msg_ids; - -#define msg_ids(ns) (*((ns)->ids[IPC_MSG_IDS])) - -#define msg_lock(ns, id) ((struct msg_queue*)ipc_lock(&msg_ids(ns), id)) #define msg_unlock(msq) ipc_unlock(&(msq)->q_perm) -#define msg_checkid(ns, msq, msgid) \ - ipc_checkid(&msg_ids(ns), &msq->q_perm, msgid) -#define msg_buildid(ns, id, seq) \ - ipc_buildid(&msg_ids(ns), id, seq) +#define msg_buildid(id, seq) ipc_buildid(id, seq) -static void freeque(struct ipc_namespace *, struct msg_queue *); +static void freeque(struct ipc_namespace *, struct kern_ipc_perm *); static int newque(struct ipc_namespace *, struct ipc_params *); #ifdef CONFIG_PROC_FS static int sysvipc_msg_proc_show(struct seq_file *s, void *it); #endif -static void __msg_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) +void msg_init_ns(struct ipc_namespace *ns) { - ns->ids[IPC_MSG_IDS] = ids; ns->msg_ctlmax = MSGMAX; ns->msg_ctlmnb = MSGMNB; ns->msg_ctlmni = MSGMNI; - ipc_init_ids(ids); + atomic_set(&ns->msg_bytes, 0); + atomic_set(&ns->msg_hdrs, 0); + ipc_init_ids(&ns->ids[IPC_MSG_IDS]); } -int msg_init_ns(struct ipc_namespace *ns) +#ifdef CONFIG_IPC_NS +void msg_exit_ns(struct ipc_namespace *ns) { - struct ipc_ids *ids; - - ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL); - if (ids == NULL) - return -ENOMEM; + free_ipcs(ns, &msg_ids(ns), freeque); +} +#endif - __msg_init_ns(ns, ids); - return 0; +void __init msg_init(void) +{ + msg_init_ns(&init_ipc_ns); + ipc_init_proc_interface("sysvipc/msg", + " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n", + IPC_MSG_IDS, sysvipc_msg_proc_show); } -void msg_exit_ns(struct ipc_namespace *ns) +/* + * This routine is called in the paths where the rw_mutex is held to protect + * access to the idr tree. + */ +static inline struct msg_queue *msg_lock_check_down(struct ipc_namespace *ns, + int id) { - struct msg_queue *msq; - int next_id; - int total, in_use; + struct kern_ipc_perm *ipcp = ipc_lock_check_down(&msg_ids(ns), id); + + if (IS_ERR(ipcp)) + return (struct msg_queue *)ipcp; - mutex_lock(&msg_ids(ns).mutex); + return container_of(ipcp, struct msg_queue, q_perm); +} - in_use = msg_ids(ns).in_use; +/* + * msg_lock_(check_) routines are called in the paths where the rw_mutex + * is not held. + */ +static inline struct msg_queue *msg_lock(struct ipc_namespace *ns, int id) +{ + struct kern_ipc_perm *ipcp = ipc_lock(&msg_ids(ns), id); - for (total = 0, next_id = 0; total < in_use; next_id++) { - msq = idr_find(&msg_ids(ns).ipcs_idr, next_id); - if (msq == NULL) - continue; - ipc_lock_by_ptr(&msq->q_perm); - freeque(ns, msq); - total++; - } - mutex_unlock(&msg_ids(ns).mutex); + if (IS_ERR(ipcp)) + return (struct msg_queue *)ipcp; - kfree(ns->ids[IPC_MSG_IDS]); - ns->ids[IPC_MSG_IDS] = NULL; + return container_of(ipcp, struct msg_queue, q_perm); } -void __init msg_init(void) +static inline struct msg_queue *msg_lock_check(struct ipc_namespace *ns, + int id) { - __msg_init_ns(&init_ipc_ns, &init_msg_ids); - ipc_init_proc_interface("sysvipc/msg", - " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n", - IPC_MSG_IDS, sysvipc_msg_proc_show); + struct kern_ipc_perm *ipcp = ipc_lock_check(&msg_ids(ns), id); + + if (IS_ERR(ipcp)) + return (struct msg_queue *)ipcp; + + return container_of(ipcp, struct msg_queue, q_perm); } static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) @@ -144,6 +148,13 @@ static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) ipc_rmid(&msg_ids(ns), &s->q_perm); } +/** + * newque - Create a new msg queue + * @ns: namespace + * @params: ptr to the structure that contains the key and msgflg + * + * Called with msg_ids.rw_mutex held (writer) + */ static int newque(struct ipc_namespace *ns, struct ipc_params *params) { struct msg_queue *msq; @@ -169,13 +180,13 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params) * ipc_addid() locks msq */ id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); - if (id == -1) { + if (id < 0) { security_msg_queue_free(msq); ipc_rcu_putref(msq); - return -ENOSPC; + return id; } - msq->q_perm.id = msg_buildid(ns, id, msq->q_perm.seq); + msq->q_perm.id = msg_buildid(id, msq->q_perm.seq); msq->q_stime = msq->q_rtime = 0; msq->q_ctime = get_seconds(); msq->q_cbytes = msq->q_qnum = 0; @@ -238,15 +249,16 @@ static void expunge_all(struct msg_queue *msq, int res) /* * freeque() wakes up waiters on the sender and receiver waiting queue, - * removes the message queue from message queue ID - * IDR, and cleans up all the messages associated with this queue. + * removes the message queue from message queue ID IDR, and cleans up all the + * messages associated with this queue. * - * msg_ids.mutex and the spinlock for this message queue are held - * before freeque() is called. msg_ids.mutex remains locked on exit. + * msg_ids.rw_mutex (writer) and the spinlock for this message queue are held + * before freeque() is called. msg_ids.rw_mutex remains locked on exit. */ -static void freeque(struct ipc_namespace *ns, struct msg_queue *msq) +static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) { struct list_head *tmp; + struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); expunge_all(msq, -EIDRM); ss_wakeup(&msq->q_senders, 1); @@ -258,17 +270,22 @@ static void freeque(struct ipc_namespace *ns, struct msg_queue *msq) struct msg_msg *msg = list_entry(tmp, struct msg_msg, m_list); tmp = tmp->next; - atomic_dec(&msg_hdrs); + atomic_dec(&ns->msg_hdrs); free_msg(msg); } - atomic_sub(msq->q_cbytes, &msg_bytes); + atomic_sub(msq->q_cbytes, &ns->msg_bytes); security_msg_queue_free(msq); ipc_rcu_putref(msq); } -static inline int msg_security(void *msq, int msgflg) +/* + * Called with msg_ids.rw_mutex and ipcp locked. + */ +static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg) { - return security_msg_queue_associate((struct msg_queue *) msq, msgflg); + struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); + + return security_msg_queue_associate(msq, msgflg); } asmlinkage long sys_msgget(key_t key, int msgflg) @@ -420,18 +437,18 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) msginfo.msgmnb = ns->msg_ctlmnb; msginfo.msgssz = MSGSSZ; msginfo.msgseg = MSGSEG; - mutex_lock(&msg_ids(ns).mutex); + down_read(&msg_ids(ns).rw_mutex); if (cmd == MSG_INFO) { msginfo.msgpool = msg_ids(ns).in_use; - msginfo.msgmap = atomic_read(&msg_hdrs); - msginfo.msgtql = atomic_read(&msg_bytes); + msginfo.msgmap = atomic_read(&ns->msg_hdrs); + msginfo.msgtql = atomic_read(&ns->msg_bytes); } else { msginfo.msgmap = MSGMAP; msginfo.msgpool = MSGPOOL; msginfo.msgtql = MSGTQL; } max_id = ipc_get_maxid(&msg_ids(ns)); - mutex_unlock(&msg_ids(ns).mutex); + up_read(&msg_ids(ns).rw_mutex); if (copy_to_user(buf, &msginfo, sizeof(struct msginfo))) return -EFAULT; return (max_id < 0) ? 0 : max_id; @@ -445,18 +462,15 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) if (!buf) return -EFAULT; - memset(&tbuf, 0, sizeof(tbuf)); - - msq = msg_lock(ns, msqid); - if (msq == NULL) - return -EINVAL; - if (cmd == MSG_STAT) { + msq = msg_lock(ns, msqid); + if (IS_ERR(msq)) + return PTR_ERR(msq); success_return = msq->q_perm.id; } else { - err = -EIDRM; - if (msg_checkid(ns, msq, msqid)) - goto out_unlock; + msq = msg_lock_check(ns, msqid); + if (IS_ERR(msq)) + return PTR_ERR(msq); success_return = 0; } err = -EACCES; @@ -467,6 +481,8 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) if (err) goto out_unlock; + memset(&tbuf, 0, sizeof(tbuf)); + kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm); tbuf.msg_stime = msq->q_stime; tbuf.msg_rtime = msq->q_rtime; @@ -493,15 +509,13 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) return -EINVAL; } - mutex_lock(&msg_ids(ns).mutex); - msq = msg_lock(ns, msqid); - err = -EINVAL; - if (msq == NULL) + down_write(&msg_ids(ns).rw_mutex); + msq = msg_lock_check_down(ns, msqid); + if (IS_ERR(msq)) { + err = PTR_ERR(msq); goto out_up; + } - err = -EIDRM; - if (msg_checkid(ns, msq, msqid)) - goto out_unlock_up; ipcp = &msq->q_perm; err = audit_ipc_obj(ipcp); @@ -550,12 +564,12 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) break; } case IPC_RMID: - freeque(ns, msq); + freeque(ns, &msq->q_perm); break; } err = 0; out_up: - mutex_unlock(&msg_ids(ns).mutex); + up_write(&msg_ids(ns).rw_mutex); return err; out_unlock_up: msg_unlock(msq); @@ -644,14 +658,11 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext, msg->m_type = mtype; msg->m_ts = msgsz; - msq = msg_lock(ns, msqid); - err = -EINVAL; - if (msq == NULL) + msq = msg_lock_check(ns, msqid); + if (IS_ERR(msq)) { + err = PTR_ERR(msq); goto out_free; - - err= -EIDRM; - if (msg_checkid(ns, msq, msqid)) - goto out_unlock_free; + } for (;;) { struct msg_sender s; @@ -701,8 +712,8 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext, list_add_tail(&msg->m_list, &msq->q_messages); msq->q_cbytes += msgsz; msq->q_qnum++; - atomic_add(msgsz, &msg_bytes); - atomic_inc(&msg_hdrs); + atomic_add(msgsz, &ns->msg_bytes); + atomic_inc(&ns->msg_hdrs); } err = 0; @@ -758,13 +769,9 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext, mode = convert_mode(&msgtyp, msgflg); ns = current->nsproxy->ipc_ns; - msq = msg_lock(ns, msqid); - if (msq == NULL) - return -EINVAL; - - msg = ERR_PTR(-EIDRM); - if (msg_checkid(ns, msq, msqid)) - goto out_unlock; + msq = msg_lock_check(ns, msqid); + if (IS_ERR(msq)) + return PTR_ERR(msq); for (;;) { struct msg_receiver msr_d; @@ -810,8 +817,8 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext, msq->q_rtime = get_seconds(); msq->q_lrpid = task_tgid_vnr(current); msq->q_cbytes -= msg->m_ts; - atomic_sub(msg->m_ts, &msg_bytes); - atomic_dec(&msg_hdrs); + atomic_sub(msg->m_ts, &ns->msg_bytes); + atomic_dec(&ns->msg_hdrs); ss_wakeup(&msq->q_senders, 0); msg_unlock(msq); break;