/* * linux/ipc/msg.c * Copyright (C) 1992 Krishna Balasubramanian * * Removed all the remaining kerneld mess * Catch the -EFAULT stuff properly * Use GFP_KERNEL for messages as in 1.2 * Fixed up the unchecked user space derefs * Copyright (C) 1998 Alan Cox & Andi Kleen * * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com> * * mostly rewritten, threaded and wake-one semantics added * MSGMAX limit removed, sysctl's added * (c) 1999 Manfred Spraul <manfred@colorfullife.com> * * support for audit of ipc object properties and permission changes * Dustin Kirkland <dustin.kirkland@us.ibm.com> * * namespaces support * OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> */ #include <linux/capability.h>#include <linux/msg.h>#include <linux/spinlock.h>#include <linux/init.h>#include <linux/mm.h>#include <linux/proc_fs.h>#include <linux/list.h>#include <linux/security.h>#include <linux/sched.h>#include <linux/syscalls.h>#include <linux/audit.h>#include <linux/seq_file.h>#include <linux/rwsem.h>#include <linux/nsproxy.h>#include <linux/ipc_namespace.h> #include <asm/current.h>#include <asm/uaccess.h>#include "util.h" /* * one msg_receiver structure for each sleeping receiver: */struct msg_receiver { struct list_head r_list; struct task_struct *r_tsk; int r_mode; long r_msgtype; long r_maxsize; struct msg_msg *volatile r_msg;}; /* one msg_sender for each sleeping sender */struct msg_sender { struct list_head list; struct task_struct *tsk;}; #define SEARCH_ANY 1#define SEARCH_EQUAL 2#define SEARCH_NOTEQUAL 3#define SEARCH_LESSEQUAL 4#define SEARCH_NUMBER 5 #define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS]) static void freeque(struct ipc_namespace *, struct kern_ipc_perm *);static int newque(struct ipc_namespace *, struct ipc_params *);#ifdef CONFIG_PROC_FSstatic int sysvipc_msg_proc_show(struct seq_file *s, void *it);#endif /* * Scale msgmni with the available lowmem size: the memory dedicated to msg * queues should occupy at most 1/MSG_MEM_SCALE of lowmem. * Also take into account the number of nsproxies created so far. * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range. */void recompute_msgmni(struct ipc_namespace *ns){ struct sysinfo i; unsigned long allowed; int nb_ns; si_meminfo(&i); allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit) / MSGMNB; nb_ns = atomic_read(&nr_ipc_ns); allowed /= nb_ns; if (allowed < MSGMNI) { ns->msg_ctlmni = MSGMNI; return; } if (allowed > IPCMNI / nb_ns) { ns->msg_ctlmni = IPCMNI / nb_ns; return; } ns->msg_ctlmni = allowed;} void msg_init_ns(struct ipc_namespace *ns){ ns->msg_ctlmax = MSGMAX; ns->msg_ctlmnb = MSGMNB; recompute_msgmni(ns); atomic_set(&ns->msg_bytes, 0); atomic_set(&ns->msg_hdrs, 0); ipc_init_ids(&ns->ids[IPC_MSG_IDS]);} #ifdef CONFIG_IPC_NSvoid msg_exit_ns(struct ipc_namespace *ns){ free_ipcs(ns, &msg_ids(ns), freeque); idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);}#endif void __init msg_init(void){ msg_init_ns(&init_ipc_ns); printk(KERN_INFO "msgmni has been set to %d\n", init_ipc_ns.msg_ctlmni); 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);} static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id){ struct kern_ipc_perm *ipcp = ipc_obtain_object(&msg_ids(ns), id); if (IS_ERR(ipcp)) return ERR_CAST(ipcp); return container_of(ipcp, struct msg_queue, q_perm);} static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns, int id){ struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id); if (IS_ERR(ipcp)) return ERR_CAST(ipcp); return container_of(ipcp, struct msg_queue, q_perm);} 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.rwsem held (writer) */static int newque(struct ipc_namespace *ns, struct ipc_params *params){ struct msg_queue *msq; int id, retval; key_t key = params->key; int msgflg = params->flg; msq = ipc_rcu_alloc(sizeof(*msq)); if (!msq) return -ENOMEM; msq->q_perm.mode = msgflg & S_IRWXUGO; msq->q_perm.key = key; msq->q_perm.security = NULL; retval = security_msg_queue_alloc(msq); if (retval) { ipc_rcu_putref(msq); return retval; } /* ipc_addid() locks msq upon success. */ id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); if (id < 0) { security_msg_queue_free(msq); ipc_rcu_putref(msq); return id; } msq->q_stime = msq->q_rtime = 0; msq->q_ctime = get_seconds(); msq->q_cbytes = msq->q_qnum = 0; msq->q_qbytes = ns->msg_ctlmnb; msq->q_lspid = msq->q_lrpid = 0; INIT_LIST_HEAD(&msq->q_messages); INIT_LIST_HEAD(&msq->q_receivers); INIT_LIST_HEAD(&msq->q_senders); ipc_unlock_object(&msq->q_perm); rcu_read_unlock(); return msq->q_perm.id;} static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss){ mss->tsk = current; current->state = TASK_INTERRUPTIBLE; list_add_tail(&mss->list, &msq->q_senders);} static inline void ss_del(struct msg_sender *mss){ if (mss->list.next != NULL) list_del(&mss->list);} static void ss_wakeup(struct list_head *h, int kill){ struct msg_sender *mss, *t; list_for_each_entry_safe(mss, t, h, list) { if (kill) mss->list.next = NULL; wake_up_process(mss->tsk); }} static void expunge_all(struct msg_queue *msq, int res){ struct msg_receiver *msr, *t; list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) { msr->r_msg = NULL; wake_up_process(msr->r_tsk); smp_mb(); msr->r_msg = ERR_PTR(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. * * msg_ids.rwsem (writer) and the spinlock for this message queue are held * before freeque() is called. msg_ids.rwsem remains locked on exit. */static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp){ struct msg_msg *msg, *t; struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); expunge_all(msq, -EIDRM); ss_wakeup(&msq->q_senders, 1); msg_rmid(ns, msq); ipc_unlock_object(&msq->q_perm); rcu_read_unlock(); list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) { atomic_dec(&ns->msg_hdrs); free_msg(msg); } atomic_sub(msq->q_cbytes, &ns->msg_bytes); security_msg_queue_free(msq); ipc_rcu_putref(msq);} /* * Called with msg_ids.rwsem and ipcp locked. */static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg){ struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); return security_msg_queue_associate(msq, msgflg);} SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg){ struct ipc_namespace *ns; struct ipc_ops msg_ops; struct ipc_params msg_params; ns = current->nsproxy->ipc_ns; msg_ops.getnew = newque; msg_ops.associate = msg_security; msg_ops.more_checks = NULL; msg_params.key = key; msg_params.flg = msgflg; return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);} static inline unsigned longcopy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version){ switch(version) { case IPC_64: return copy_to_user(buf, in, sizeof(*in)); case IPC_OLD: { struct msqid_ds out; memset(&out, 0, sizeof(out)); ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); out.msg_stime = in->msg_stime; out.msg_rtime = in->msg_rtime; out.msg_ctime = in->msg_ctime; if (in->msg_cbytes > USHRT_MAX) out.msg_cbytes = USHRT_MAX; else out.msg_cbytes = in->msg_cbytes; out.msg_lcbytes = in->msg_cbytes; if (in->msg_qnum > USHRT_MAX) out.msg_qnum = USHRT_MAX; else out.msg_qnum = in->msg_qnum; if (in->msg_qbytes > USHRT_MAX) out.msg_qbytes = USHRT_MAX; else out.msg_qbytes = in->msg_qbytes; out.msg_lqbytes = in->msg_qbytes; out.msg_lspid = in->msg_lspid; out.msg_lrpid = in->msg_lrpid; return copy_to_user(buf, &out, sizeof(out)); } default: return -EINVAL; }} static inline unsigned longcopy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version){ switch(version) { case IPC_64: if (copy_from_user(out, buf, sizeof(*out))) return -EFAULT; return 0; case IPC_OLD: { struct msqid_ds tbuf_old; if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) return -EFAULT; out->msg_perm.uid = tbuf_old.msg_perm.uid; out->msg_perm.gid = tbuf_old.msg_perm.gid; out->msg_perm.mode = tbuf_old.msg_perm.mode; if (tbuf_old.msg_qbytes == 0) out->msg_qbytes = tbuf_old.msg_lqbytes; else out->msg_qbytes = tbuf_old.msg_qbytes; return 0; } default: return -EINVAL; }} /* * This function handles some msgctl commands which require the rwsem * to be held in write mode. * NOTE: no locks must be held, the rwsem is taken inside this function. */static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd, struct msqid_ds __user *buf, int version){ struct kern_ipc_perm *ipcp; struct msqid64_ds uninitialized_var(msqid64); struct msg_queue *msq; int err; if (cmd == IPC_SET) { if (copy_msqid_from_user(&msqid64, buf, version)) return -EFAULT; } down_write(&msg_ids(ns).rwsem); rcu_read_lock(); ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd, &msqid64.msg_perm, msqid64.msg_qbytes); if (IS_ERR(ipcp)) { err = PTR_ERR(ipcp); goto out_unlock1; } msq = container_of(ipcp, struct msg_queue, q_perm); err = security_msg_queue_msgctl(msq, cmd); if (err) goto out_unlock1; switch (cmd) { case IPC_RMID: ipc_lock_object(&msq->q_perm); /* freeque unlocks the ipc object and rcu */ freeque(ns, ipcp); goto out_up; case IPC_SET: if (msqid64.msg_qbytes > ns->msg_ctlmnb && !capable(CAP_SYS_RESOURCE)) { err = -EPERM; goto out_unlock1; } ipc_lock_object(&msq->q_perm); err = ipc_update_perm(&msqid64.msg_perm, ipcp); if (err) goto out_unlock0; msq->q_qbytes = msqid64.msg_qbytes; msq->q_ctime = get_seconds(); /* sleeping receivers might be excluded by * stricter permissions. */ expunge_all(msq, -EAGAIN); /* sleeping senders might be able to send * due to a larger queue size. */ ss_wakeup(&msq->q_senders, 0); break; default: err = -EINVAL; goto out_unlock1; } out_unlock0: ipc_unlock_object(&msq->q_perm);out_unlock1: rcu_read_unlock();out_up: up_write(&msg_ids(ns).rwsem); return err;} static int msgctl_nolock(struct ipc_namespace *ns, int msqid, int cmd, int version, void __user *buf){ int err; struct msg_queue *msq; switch (cmd) { case IPC_INFO: case MSG_INFO: { struct msginfo msginfo; int max_id; if (!buf) return -EFAULT; /* * We must not return kernel stack data. * due to padding, it's not enough * to set all member fields. */ err = security_msg_queue_msgctl(NULL, cmd); if (err) return err; memset(&msginfo, 0, sizeof(msginfo)); msginfo.msgmni = ns->msg_ctlmni; msginfo.msgmax = ns->msg_ctlmax; msginfo.msgmnb = ns->msg_ctlmnb; msginfo.msgssz = MSGSSZ; msginfo.msgseg = MSGSEG; down_read(&msg_ids(ns).rwsem); if (cmd == MSG_INFO) { msginfo.msgpool = msg_ids(ns).in_use; msginfo.msgmap = atomic_read(&ns->msg_hdrs); msginfo.msgtql = atomic_read(&ns->msg_bytes);Lines 1–500 of 1044. 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/* * linux/ipc/msg.c * Copyright (C) 1992 Krishna Balasubramanian * * Removed all the remaining kerneld mess * Catch the -EFAULT stuff properly * Use GFP_KERNEL for messages as in 1.2 * Fixed up the unchecked user space derefs * Copyright (C) 1998 Alan Cox & Andi Kleen * * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com> * * mostly rewritten, threaded and wake-one semantics added * MSGMAX limit removed, sysctl's added * (c) 1999 Manfred Spraul <manfred@colorfullife.com> * * support for audit of ipc object properties and permission changes * Dustin Kirkland <dustin.kirkland@us.ibm.com> * * namespaces support * OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> */ #include <linux/capability.h> #include <linux/msg.h> #include <linux/spinlock.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/proc_fs.h> #include <linux/list.h> #include <linux/security.h> #include <linux/sched.h> #include <linux/syscalls.h> #include <linux/audit.h> #include <linux/seq_file.h> #include <linux/rwsem.h> #include <linux/nsproxy.h> #include <linux/ipc_namespace.h> #include <asm/current.h> #include <asm/uaccess.h> #include "util.h" /* * one msg_receiver structure for each sleeping receiver: */ struct msg_receiver { struct list_head r_list; struct task_struct *r_tsk; int r_mode; long r_msgtype; long r_maxsize; struct msg_msg *volatile r_msg; }; /* one msg_sender for each sleeping sender */ struct msg_sender { struct list_head list; struct task_struct *tsk; }; #define SEARCH_ANY 1 #define SEARCH_EQUAL 2 #define SEARCH_NOTEQUAL 3 #define SEARCH_LESSEQUAL 4 #define SEARCH_NUMBER 5 #define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS]) 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 /* * Scale msgmni with the available lowmem size: the memory dedicated to msg * queues should occupy at most 1/MSG_MEM_SCALE of lowmem. * Also take into account the number of nsproxies created so far. * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range. */ void recompute_msgmni(struct ipc_namespace *ns) { struct sysinfo i; unsigned long allowed; int nb_ns; si_meminfo(&i); allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit) / MSGMNB; nb_ns = atomic_read(&nr_ipc_ns); allowed /= nb_ns; if (allowed < MSGMNI) { ns->msg_ctlmni = MSGMNI; return; } if (allowed > IPCMNI / nb_ns) { ns->msg_ctlmni = IPCMNI / nb_ns; return; } ns->msg_ctlmni = allowed; } void msg_init_ns(struct ipc_namespace *ns) { ns->msg_ctlmax = MSGMAX; ns->msg_ctlmnb = MSGMNB; recompute_msgmni(ns); atomic_set(&ns->msg_bytes, 0); atomic_set(&ns->msg_hdrs, 0); ipc_init_ids(&ns->ids[IPC_MSG_IDS]); } #ifdef CONFIG_IPC_NS void msg_exit_ns(struct ipc_namespace *ns) { free_ipcs(ns, &msg_ids(ns), freeque); idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr); } #endif void __init msg_init(void) { msg_init_ns(&init_ipc_ns); printk(KERN_INFO "msgmni has been set to %d\n", init_ipc_ns.msg_ctlmni); 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); } static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id) { struct kern_ipc_perm *ipcp = ipc_obtain_object(&msg_ids(ns), id); if (IS_ERR(ipcp)) return ERR_CAST(ipcp); return container_of(ipcp, struct msg_queue, q_perm); } static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns, int id) { struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id); if (IS_ERR(ipcp)) return ERR_CAST(ipcp); return container_of(ipcp, struct msg_queue, q_perm); } 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.rwsem held (writer) */ static int newque(struct ipc_namespace *ns, struct ipc_params *params) { struct msg_queue *msq; int id, retval; key_t key = params->key; int msgflg = params->flg; msq = ipc_rcu_alloc(sizeof(*msq)); if (!msq) return -ENOMEM; msq->q_perm.mode = msgflg & S_IRWXUGO; msq->q_perm.key = key; msq->q_perm.security = NULL; retval = security_msg_queue_alloc(msq); if (retval) { ipc_rcu_putref(msq); return retval; } /* ipc_addid() locks msq upon success. */ id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); if (id < 0) { security_msg_queue_free(msq); ipc_rcu_putref(msq); return id; } msq->q_stime = msq->q_rtime = 0; msq->q_ctime = get_seconds(); msq->q_cbytes = msq->q_qnum = 0; msq->q_qbytes = ns->msg_ctlmnb; msq->q_lspid = msq->q_lrpid = 0; INIT_LIST_HEAD(&msq->q_messages); INIT_LIST_HEAD(&msq->q_receivers); INIT_LIST_HEAD(&msq->q_senders); ipc_unlock_object(&msq->q_perm); rcu_read_unlock(); return msq->q_perm.id; } static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss) { mss->tsk = current; current->state = TASK_INTERRUPTIBLE; list_add_tail(&mss->list, &msq->q_senders); } static inline void ss_del(struct msg_sender *mss) { if (mss->list.next != NULL) list_del(&mss->list); } static void ss_wakeup(struct list_head *h, int kill) { struct msg_sender *mss, *t; list_for_each_entry_safe(mss, t, h, list) { if (kill) mss->list.next = NULL; wake_up_process(mss->tsk); } } static void expunge_all(struct msg_queue *msq, int res) { struct msg_receiver *msr, *t; list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) { msr->r_msg = NULL; wake_up_process(msr->r_tsk); smp_mb(); msr->r_msg = ERR_PTR(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. * * msg_ids.rwsem (writer) and the spinlock for this message queue are held * before freeque() is called. msg_ids.rwsem remains locked on exit. */ static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) { struct msg_msg *msg, *t; struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); expunge_all(msq, -EIDRM); ss_wakeup(&msq->q_senders, 1); msg_rmid(ns, msq); ipc_unlock_object(&msq->q_perm); rcu_read_unlock(); list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) { atomic_dec(&ns->msg_hdrs); free_msg(msg); } atomic_sub(msq->q_cbytes, &ns->msg_bytes); security_msg_queue_free(msq); ipc_rcu_putref(msq); } /* * Called with msg_ids.rwsem and ipcp locked. */ static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg) { struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); return security_msg_queue_associate(msq, msgflg); } SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg) { struct ipc_namespace *ns; struct ipc_ops msg_ops; struct ipc_params msg_params; ns = current->nsproxy->ipc_ns; msg_ops.getnew = newque; msg_ops.associate = msg_security; msg_ops.more_checks = NULL; msg_params.key = key; msg_params.flg = msgflg; return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params); } static inline unsigned long copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version) { switch(version) { case IPC_64: return copy_to_user(buf, in, sizeof(*in)); case IPC_OLD: { struct msqid_ds out; memset(&out, 0, sizeof(out)); ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); out.msg_stime = in->msg_stime; out.msg_rtime = in->msg_rtime; out.msg_ctime = in->msg_ctime; if (in->msg_cbytes > USHRT_MAX) out.msg_cbytes = USHRT_MAX; else out.msg_cbytes = in->msg_cbytes; out.msg_lcbytes = in->msg_cbytes; if (in->msg_qnum > USHRT_MAX) out.msg_qnum = USHRT_MAX; else out.msg_qnum = in->msg_qnum; if (in->msg_qbytes > USHRT_MAX) out.msg_qbytes = USHRT_MAX; else out.msg_qbytes = in->msg_qbytes; out.msg_lqbytes = in->msg_qbytes; out.msg_lspid = in->msg_lspid; out.msg_lrpid = in->msg_lrpid; return copy_to_user(buf, &out, sizeof(out)); } default: return -EINVAL; } } static inline unsigned long copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version) { switch(version) { case IPC_64: if (copy_from_user(out, buf, sizeof(*out))) return -EFAULT; return 0; case IPC_OLD: { struct msqid_ds tbuf_old; if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) return -EFAULT; out->msg_perm.uid = tbuf_old.msg_perm.uid; out->msg_perm.gid = tbuf_old.msg_perm.gid; out->msg_perm.mode = tbuf_old.msg_perm.mode; if (tbuf_old.msg_qbytes == 0) out->msg_qbytes = tbuf_old.msg_lqbytes; else out->msg_qbytes = tbuf_old.msg_qbytes; return 0; } default: return -EINVAL; } } /* * This function handles some msgctl commands which require the rwsem * to be held in write mode. * NOTE: no locks must be held, the rwsem is taken inside this function. */ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd, struct msqid_ds __user *buf, int version) { struct kern_ipc_perm *ipcp; struct msqid64_ds uninitialized_var(msqid64); struct msg_queue *msq; int err; if (cmd == IPC_SET) { if (copy_msqid_from_user(&msqid64, buf, version)) return -EFAULT; } down_write(&msg_ids(ns).rwsem); rcu_read_lock(); ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd, &msqid64.msg_perm, msqid64.msg_qbytes); if (IS_ERR(ipcp)) { err = PTR_ERR(ipcp); goto out_unlock1; } msq = container_of(ipcp, struct msg_queue, q_perm); err = security_msg_queue_msgctl(msq, cmd); if (err) goto out_unlock1; switch (cmd) { case IPC_RMID: ipc_lock_object(&msq->q_perm); /* freeque unlocks the ipc object and rcu */ freeque(ns, ipcp); goto out_up; case IPC_SET: if (msqid64.msg_qbytes > ns->msg_ctlmnb && !capable(CAP_SYS_RESOURCE)) { err = -EPERM; goto out_unlock1; } ipc_lock_object(&msq->q_perm); err = ipc_update_perm(&msqid64.msg_perm, ipcp); if (err) goto out_unlock0; msq->q_qbytes = msqid64.msg_qbytes; msq->q_ctime = get_seconds(); /* sleeping receivers might be excluded by * stricter permissions. */ expunge_all(msq, -EAGAIN); /* sleeping senders might be able to send * due to a larger queue size. */ ss_wakeup(&msq->q_senders, 0); break; default: err = -EINVAL; goto out_unlock1; } out_unlock0: ipc_unlock_object(&msq->q_perm); out_unlock1: rcu_read_unlock(); out_up: up_write(&msg_ids(ns).rwsem); return err; } static int msgctl_nolock(struct ipc_namespace *ns, int msqid, int cmd, int version, void __user *buf) { int err; struct msg_queue *msq; switch (cmd) { case IPC_INFO: case MSG_INFO: { struct msginfo msginfo; int max_id; if (!buf) return -EFAULT; /* * We must not return kernel stack data. * due to padding, it's not enough * to set all member fields. */ err = security_msg_queue_msgctl(NULL, cmd); if (err) return err; memset(&msginfo, 0, sizeof(msginfo)); msginfo.msgmni = ns->msg_ctlmni; msginfo.msgmax = ns->msg_ctlmax; msginfo.msgmnb = ns->msg_ctlmnb; msginfo.msgssz = MSGSSZ; msginfo.msgseg = MSGSEG; down_read(&msg_ids(ns).rwsem); if (cmd == MSG_INFO) { msginfo.msgpool = msg_ids(ns).in_use; msginfo.msgmap = atomic_read(&ns->msg_hdrs); msginfo.msgtql = atomic_read(&ns->msg_bytes);