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ipc/util.c
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/* * linux/ipc/util.c * Copyright (C) 1992 Krishna Balasubramanian * * Sep 1997 - Call suser() last after "normal" permission checks so we * get BSD style process accounting right. * Occurs in several places in the IPC code. * Chris Evans, <chris@ferret.lmh.ox.ac.uk> * Nov 1999 - ipc helper functions, unified SMP locking |
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* Manfred Spraul <manfred@colorfullife.com> |
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* Oct 2002 - One lock per IPC id. RCU ipc_free for lock-free grow_ary(). * Mingming Cao <cmm@us.ibm.com> |
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* Mar 2006 - support for audit of ipc object properties * Dustin Kirkland <dustin.kirkland@us.ibm.com> |
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* Jun 2006 - namespaces ssupport * OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> |
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* * General sysv ipc locking scheme: |
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* rcu_read_lock() * obtain the ipc object (kern_ipc_perm) by looking up the id in an idr * tree. * - perform initial checks (capabilities, auditing and permission, * etc). * - perform read-only operations, such as STAT, INFO commands. * acquire the ipc lock (kern_ipc_perm.lock) through * ipc_lock_object() * - perform data updates, such as SET, RMID commands and * mechanism-specific operations (semop/semtimedop, * msgsnd/msgrcv, shmat/shmdt). * drop the ipc lock, through ipc_unlock_object(). * rcu_read_unlock() * * The ids->rwsem must be taken when: * - creating, removing and iterating the existing entries in ipc * identifier sets. * - iterating through files under /proc/sysvipc/ * * Note that sems have a special fast path that avoids kern_ipc_perm.lock - * see sem_lock(). |
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*/ |
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#include <linux/mm.h> #include <linux/shm.h> #include <linux/init.h> #include <linux/msg.h> |
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#include <linux/vmalloc.h> #include <linux/slab.h> |
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#include <linux/notifier.h> |
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#include <linux/capability.h> |
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#include <linux/highuid.h> #include <linux/security.h> #include <linux/rcupdate.h> #include <linux/workqueue.h> |
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#include <linux/seq_file.h> #include <linux/proc_fs.h> |
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#include <linux/audit.h> |
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#include <linux/nsproxy.h> |
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#include <linux/rwsem.h> |
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#include <linux/memory.h> |
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#include <linux/ipc_namespace.h> |
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#include <asm/unistd.h> #include "util.h" |
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struct ipc_proc_iface { const char *path; const char *header; |
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int ids; |
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int (*show)(struct seq_file *, void *); }; |
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static void ipc_memory_notifier(struct work_struct *work) { ipcns_notify(IPCNS_MEMCHANGED); } |
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static int ipc_memory_callback(struct notifier_block *self, unsigned long action, void *arg) { |
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static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier); |
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switch (action) { case MEM_ONLINE: /* memory successfully brought online */ case MEM_OFFLINE: /* or offline: it's time to recompute msgmni */ /* * This is done by invoking the ipcns notifier chain with the * IPC_MEMCHANGED event. |
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* In order not to keep the lock on the hotplug memory chain * for too long, queue a work item that will, when waken up, * activate the ipcns notification chain. |
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*/ |
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schedule_work(&ipc_memory_wq); |
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break; case MEM_GOING_ONLINE: case MEM_GOING_OFFLINE: case MEM_CANCEL_ONLINE: case MEM_CANCEL_OFFLINE: default: break; } return NOTIFY_OK; } |
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static struct notifier_block ipc_memory_nb = { .notifier_call = ipc_memory_callback, .priority = IPC_CALLBACK_PRI, }; |
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|
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/** |
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* ipc_init - initialise ipc subsystem |
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* |
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* The various sysv ipc resources (semaphores, messages and shared * memory) are initialised. * * A callback routine is registered into the memory hotplug notifier * chain: since msgmni scales to lowmem this callback routine will be * called upon successful memory add / remove to recompute msmgni. |
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*/ |
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static int __init ipc_init(void) { sem_init(); msg_init(); shm_init(); |
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register_hotmemory_notifier(&ipc_memory_nb); |
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register_ipcns_notifier(&init_ipc_ns); |
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return 0; } |
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device_initcall(ipc_init); |
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/** |
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* ipc_init_ids - initialise ipc identifiers * @ids: ipc identifier set |
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* |
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* Set up the sequence range to use for the ipc identifier range (limited * below IPCMNI) then initialise the ids idr. |
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*/ |
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void ipc_init_ids(struct ipc_ids *ids) |
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{ |
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ids->in_use = 0; |
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ids->seq = 0; |
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ids->next_id = -1; |
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init_rwsem(&ids->rwsem); |
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idr_init(&ids->ipcs_idr); |
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} |
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#ifdef CONFIG_PROC_FS |
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static const struct file_operations sysvipc_proc_fops; |
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/** |
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* ipc_init_proc_interface - create a proc interface for sysipc types using a seq_file interface. * @path: Path in procfs * @header: Banner to be printed at the beginning of the file. * @ids: ipc id table to iterate. * @show: show routine. |
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*/ void __init ipc_init_proc_interface(const char *path, const char *header, |
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int ids, int (*show)(struct seq_file *, void *)) |
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{ struct proc_dir_entry *pde; struct ipc_proc_iface *iface; iface = kmalloc(sizeof(*iface), GFP_KERNEL); if (!iface) return; iface->path = path; iface->header = header; iface->ids = ids; iface->show = show; |
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pde = proc_create_data(path, S_IRUGO, /* world readable */ NULL, /* parent dir */ &sysvipc_proc_fops, iface); |
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if (!pde) |
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kfree(iface); |
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} #endif |
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/** |
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* ipc_findkey - find a key in an ipc identifier set * @ids: ipc identifier set * @key: key to find |
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* |
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* Returns the locked pointer to the ipc structure if found or NULL * otherwise. If key is found ipc points to the owning ipc structure * * Called with ipc_ids.rwsem held. |
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*/ |
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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; int next_id; int total; |
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for (total = 0, next_id = 0; total < ids->in_use; next_id++) { ipc = idr_find(&ids->ipcs_idr, next_id); if (ipc == NULL) |
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continue; |
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if (ipc->key != key) { total++; continue; } |
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rcu_read_lock(); ipc_lock_object(ipc); |
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return ipc; |
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} |
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return NULL; |
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} |
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/** |
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* ipc_get_maxid - get the last assigned id * @ids: ipc identifier set |
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* |
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* Called with ipc_ids.rwsem held. |
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*/ |
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int ipc_get_maxid(struct ipc_ids *ids) { struct kern_ipc_perm *ipc; int max_id = -1; int total, id; if (ids->in_use == 0) return -1; |
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if (ids->in_use == IPCMNI) return IPCMNI - 1; /* Look for the last assigned id */ total = 0; for (id = 0; id < IPCMNI && total < ids->in_use; id++) { ipc = idr_find(&ids->ipcs_idr, id); if (ipc != NULL) { max_id = id; total++; } } return max_id; |
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} /** |
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* ipc_addid - add an ipc identifier * @ids: ipc identifier set * @new: new ipc permission set * @size: limit for the number of used ids |
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* |
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* Add an entry 'new' to the ipc ids idr. The permissions object is * initialised and the first free entry is set up and the id assigned * is returned. The 'new' entry is returned in a locked state on success. * On failure the entry is not locked and a negative err-code is returned. |
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* |
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* Called with writer ipc_ids.rwsem held. |
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*/ |
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int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size) |
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{ |
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kuid_t euid; kgid_t egid; |
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int id; |
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int next_id = ids->next_id; |
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if (size > IPCMNI) size = IPCMNI; if (ids->in_use >= size) |
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return -ENOSPC; |
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|
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idr_preload(GFP_KERNEL); |
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spin_lock_init(&new->lock); |
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new->deleted = false; |
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rcu_read_lock(); spin_lock(&new->lock); |
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id = idr_alloc(&ids->ipcs_idr, new, (next_id < 0) ? 0 : ipcid_to_idx(next_id), 0, GFP_NOWAIT); idr_preload_end(); if (id < 0) { |
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spin_unlock(&new->lock); rcu_read_unlock(); |
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return id; |
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} |
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ids->in_use++; |
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current_euid_egid(&euid, &egid); new->cuid = new->uid = euid; new->gid = new->cgid = egid; |
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|
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if (next_id < 0) { new->seq = ids->seq++; |
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if (ids->seq > IPCID_SEQ_MAX) |
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ids->seq = 0; } else { new->seq = ipcid_to_seqx(next_id); ids->next_id = -1; } |
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new->id = ipc_buildid(id, new->seq); |
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return id; } /** |
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* ipcget_new - create a new ipc object * @ns: ipc namespace |
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* @ids: ipc identifier set |
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* @ops: the actual creation routine to call * @params: its parameters * * This routine is called by sys_msgget, sys_semget() and sys_shmget() * when the key is IPC_PRIVATE. |
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*/ |
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static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids, |
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const struct ipc_ops *ops, struct ipc_params *params) |
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{ int err; |
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down_write(&ids->rwsem); |
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err = ops->getnew(ns, params); |
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up_write(&ids->rwsem); |
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return err; } /** |
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* ipc_check_perms - check security and permissions for an ipc object * @ns: ipc namespace * @ipcp: ipc permission set * @ops: the actual security routine to call * @params: its parameters |
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* |
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* This routine is called by sys_msgget(), sys_semget() and sys_shmget() * when the key is not IPC_PRIVATE and that key already exists in the * ds IDR. |
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* |
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* On success, the ipc id is returned. |
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* |
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* It is called with ipc_ids.rwsem and ipcp->lock held. |
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*/ |
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static int ipc_check_perms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, |
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const struct ipc_ops *ops, |
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struct ipc_params *params) |
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{ int err; |
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if (ipcperms(ns, ipcp, params->flg)) |
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err = -EACCES; else { err = ops->associate(ipcp, params->flg); if (!err) err = ipcp->id; } return err; } /** |
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* ipcget_public - get an ipc object or create a new one * @ns: ipc namespace |
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* @ids: ipc identifier set |
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* @ops: the actual creation routine to call * @params: its parameters * * This routine is called by sys_msgget, sys_semget() and sys_shmget() * when the key is not IPC_PRIVATE. * It adds a new entry if the key is not found and does some permission * / security checkings if the key is found. * * On success, the ipc id is returned. |
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*/ |
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static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids, |
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const struct ipc_ops *ops, struct ipc_params *params) |
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{ struct kern_ipc_perm *ipcp; int flg = params->flg; int err; |
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/* * Take the lock as a writer since we are potentially going to add * a new entry + read locks are not "upgradable" */ |
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down_write(&ids->rwsem); |
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ipcp = ipc_findkey(ids, params->key); if (ipcp == NULL) { /* key not used */ if (!(flg & IPC_CREAT)) err = -ENOENT; |
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else err = ops->getnew(ns, params); } else { /* ipc object has been locked by ipc_findkey() */ if (flg & IPC_CREAT && flg & IPC_EXCL) err = -EEXIST; else { err = 0; if (ops->more_checks) err = ops->more_checks(ipcp, params); if (!err) |
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/* * ipc_check_perms returns the IPC id on * success */ |
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err = ipc_check_perms(ns, ipcp, ops, params); |
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} ipc_unlock(ipcp); } |
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up_write(&ids->rwsem); |
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return err; } /** |
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* ipc_rmid - remove an ipc identifier * @ids: ipc identifier set * @ipcp: ipc perm structure containing the identifier to remove |
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* |
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* ipc_ids.rwsem (as a writer) and the spinlock for this ID are held * before this function is called, and remain locked on the exit. |
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*/ |
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void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp) |
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{ |
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int lid = ipcid_to_idx(ipcp->id); |
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idr_remove(&ids->ipcs_idr, lid); |
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ids->in_use--; |
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ipcp->deleted = true; |
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} /** |
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* ipc_alloc - allocate ipc space * @size: size desired |
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* |
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* Allocate memory from the appropriate pools and return a pointer to it. * NULL is returned if the allocation fails |
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*/ |
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void *ipc_alloc(int size) |
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{ |
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void *out; |
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if (size > PAGE_SIZE) |
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out = vmalloc(size); else out = kmalloc(size, GFP_KERNEL); return out; } /** |
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* ipc_free - free ipc space * @ptr: pointer returned by ipc_alloc * @size: size of block |
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* |
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* Free a block created with ipc_alloc(). The caller must know the size * used in the allocation call. |
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*/ |
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void ipc_free(void *ptr, int size) |
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{ |
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if (size > PAGE_SIZE) |
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vfree(ptr); else kfree(ptr); } |
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/** |
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* ipc_rcu_alloc - allocate ipc and rcu space * @size: size desired |
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* |
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* Allocate memory for the rcu header structure + the object. * Returns the pointer to the object or NULL upon failure. |
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*/ |
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void *ipc_rcu_alloc(int size) |
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{ |
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/* |
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* We prepend the allocation with the rcu struct |
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*/ |
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struct ipc_rcu *out = ipc_alloc(sizeof(struct ipc_rcu) + size); if (unlikely(!out)) return NULL; atomic_set(&out->refcount, 1); |
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return out + 1; |
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} |
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int ipc_rcu_getref(void *ptr) |
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{ |
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struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1; return atomic_inc_not_zero(&p->refcount); |
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} |
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void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head)) |
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{ |
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struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1; |
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if (!atomic_dec_and_test(&p->refcount)) |
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return; |
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call_rcu(&p->rcu, func); } void ipc_rcu_free(struct rcu_head *head) { struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu); if (is_vmalloc_addr(p)) vfree(p); else kfree(p); |
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} /** |
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* ipcperms - check ipc permissions * @ns: ipc namespace * @ipcp: ipc permission set * @flag: desired permission set |
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* |
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* Check user, group, other permissions for access * to ipc resources. return 0 if allowed |
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* |
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507 |
* @flag will most probably be 0 or S_...UGO from <linux/stat.h> |
1da177e4c
|
508 |
*/ |
b0e77598f
|
509 510 |
int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag) { |
1efdb69b0
|
511 |
kuid_t euid = current_euid(); |
a33e67510
|
512 |
int requested_mode, granted_mode; |
1da177e4c
|
513 |
|
a33e67510
|
514 |
audit_ipc_obj(ipcp); |
1da177e4c
|
515 516 |
requested_mode = (flag >> 6) | (flag >> 3) | flag; granted_mode = ipcp->mode; |
1efdb69b0
|
517 518 |
if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid)) |
1da177e4c
|
519 520 521 522 |
granted_mode >>= 6; else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid)) granted_mode >>= 3; /* is there some bit set in requested_mode but not in granted_mode? */ |
46c0a8ca3
|
523 |
if ((requested_mode & ~granted_mode & 0007) && |
b0e77598f
|
524 |
!ns_capable(ns->user_ns, CAP_IPC_OWNER)) |
1da177e4c
|
525 526 527 528 529 530 531 532 533 534 535 |
return -1; return security_ipc_permission(ipcp, flag); } /* * Functions to convert between the kern_ipc_perm structure and the * old/new ipc_perm structures */ /** |
8001c8581
|
536 537 538 |
* kernel_to_ipc64_perm - convert kernel ipc permissions to user * @in: kernel permissions * @out: new style ipc permissions |
1da177e4c
|
539 |
* |
8001c8581
|
540 541 |
* Turn the kernel object @in into a set of permissions descriptions * for returning to userspace (@out). |
1da177e4c
|
542 |
*/ |
239521f31
|
543 |
void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out) |
1da177e4c
|
544 545 |
{ out->key = in->key; |
1efdb69b0
|
546 547 548 549 |
out->uid = from_kuid_munged(current_user_ns(), in->uid); out->gid = from_kgid_munged(current_user_ns(), in->gid); out->cuid = from_kuid_munged(current_user_ns(), in->cuid); out->cgid = from_kgid_munged(current_user_ns(), in->cgid); |
1da177e4c
|
550 551 552 553 554 |
out->mode = in->mode; out->seq = in->seq; } /** |
8001c8581
|
555 556 557 |
* ipc64_perm_to_ipc_perm - convert new ipc permissions to old * @in: new style ipc permissions * @out: old style ipc permissions |
1da177e4c
|
558 |
* |
8001c8581
|
559 560 |
* Turn the new style permissions object @in into a compatibility * object and store it into the @out pointer. |
1da177e4c
|
561 |
*/ |
239521f31
|
562 |
void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out) |
1da177e4c
|
563 564 565 566 567 568 569 570 571 |
{ out->key = in->key; SET_UID(out->uid, in->uid); SET_GID(out->gid, in->gid); SET_UID(out->cuid, in->cuid); SET_GID(out->cgid, in->cgid); out->mode = in->mode; out->seq = in->seq; } |
f4566f048
|
572 |
/** |
4d2bff5eb
|
573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 |
* ipc_obtain_object * @ids: ipc identifier set * @id: ipc id to look for * * Look for an id in the ipc ids idr and return associated ipc object. * * Call inside the RCU critical section. * The ipc object is *not* locked on exit. */ struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id) { struct kern_ipc_perm *out; int lid = ipcid_to_idx(id); out = idr_find(&ids->ipcs_idr, lid); if (!out) return ERR_PTR(-EINVAL); return out; } /** |
8001c8581
|
595 596 |
* ipc_lock - lock an ipc structure without rwsem held * @ids: ipc identifier set |
f4566f048
|
597 598 599 600 |
* @id: ipc id to look for * * Look for an id in the ipc ids idr and lock the associated ipc object. * |
4d2bff5eb
|
601 |
* The ipc object is locked on successful exit. |
f4566f048
|
602 |
*/ |
7ca7e564e
|
603 |
struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id) |
1da177e4c
|
604 |
{ |
7ca7e564e
|
605 |
struct kern_ipc_perm *out; |
1da177e4c
|
606 607 |
rcu_read_lock(); |
4d2bff5eb
|
608 609 610 |
out = ipc_obtain_object(ids, id); if (IS_ERR(out)) goto err1; |
7ca7e564e
|
611 |
|
1da177e4c
|
612 |
spin_lock(&out->lock); |
4d2bff5eb
|
613 |
|
1da177e4c
|
614 615 616 |
/* ipc_rmid() may have already freed the ID while ipc_lock * was spinning: here verify that the structure is still valid */ |
72a8ff2f9
|
617 |
if (ipc_valid_object(out)) |
4d2bff5eb
|
618 619 620 621 622 623 624 625 |
return out; spin_unlock(&out->lock); out = ERR_PTR(-EINVAL); err1: rcu_read_unlock(); return out; } |
7ca7e564e
|
626 |
|
4d2bff5eb
|
627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 |
/** * ipc_obtain_object_check * @ids: ipc identifier set * @id: ipc id to look for * * Similar to ipc_obtain_object() but also checks * the ipc object reference counter. * * Call inside the RCU critical section. * The ipc object is *not* locked on exit. */ struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id) { struct kern_ipc_perm *out = ipc_obtain_object(ids, id); if (IS_ERR(out)) goto out; if (ipc_checkid(out, id)) return ERR_PTR(-EIDRM); out: |
1da177e4c
|
648 649 |
return out; } |
b2d75cddc
|
650 651 |
/** * ipcget - Common sys_*get() code |
da3dae54e
|
652 |
* @ns: namespace |
8001c8581
|
653 654 655 656 |
* @ids: ipc identifier set * @ops: operations to be called on ipc object creation, permission checks * and further checks * @params: the parameters needed by the previous operations. |
b2d75cddc
|
657 658 659 660 |
* * Common routine called by sys_msgget(), sys_semget() and sys_shmget(). */ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, |
eb66ec44f
|
661 |
const struct ipc_ops *ops, struct ipc_params *params) |
b2d75cddc
|
662 663 664 665 666 667 |
{ if (params->key == IPC_PRIVATE) return ipcget_new(ns, ids, ops, params); else return ipcget_public(ns, ids, ops, params); } |
8f4a3809c
|
668 |
/** |
8001c8581
|
669 |
* ipc_update_perm - update the permissions of an ipc object |
8f4a3809c
|
670 671 672 |
* @in: the permission given as input. * @out: the permission of the ipc to set. */ |
1efdb69b0
|
673 |
int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out) |
8f4a3809c
|
674 |
{ |
1efdb69b0
|
675 676 677 678 679 680 681 |
kuid_t uid = make_kuid(current_user_ns(), in->uid); kgid_t gid = make_kgid(current_user_ns(), in->gid); if (!uid_valid(uid) || !gid_valid(gid)) return -EINVAL; out->uid = uid; out->gid = gid; |
8f4a3809c
|
682 683 |
out->mode = (out->mode & ~S_IRWXUGO) | (in->mode & S_IRWXUGO); |
1efdb69b0
|
684 685 |
return 0; |
8f4a3809c
|
686 |
} |
a5f75e7f2
|
687 |
/** |
3b1c4ad37
|
688 |
* ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd |
8001c8581
|
689 |
* @ns: ipc namespace |
a5f75e7f2
|
690 691 692 693 694 695 696 697 698 699 700 |
* @ids: the table of ids where to look for the ipc * @id: the id of the ipc to retrieve * @cmd: the cmd to check * @perm: the permission to set * @extra_perm: one extra permission parameter used by msq * * This function does some common audit and permissions check for some IPC_XXX * cmd and is called from semctl_down, shmctl_down and msgctl_down. * It must be called without any lock held and * - retrieves the ipc with the given id in the given table. * - performs some audit and permission check, depending on the given cmd |
3b1c4ad37
|
701 |
* - returns a pointer to the ipc object or otherwise, the corresponding error. |
7b4cc5d84
|
702 |
* |
d9a605e40
|
703 |
* Call holding the both the rwsem and the rcu read lock. |
a5f75e7f2
|
704 |
*/ |
444d0f621
|
705 |
struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns, |
3b1c4ad37
|
706 707 |
struct ipc_ids *ids, int id, int cmd, struct ipc64_perm *perm, int extra_perm) |
444d0f621
|
708 |
{ |
1efdb69b0
|
709 |
kuid_t euid; |
444d0f621
|
710 711 |
int err = -EPERM; struct kern_ipc_perm *ipcp; |
a5f75e7f2
|
712 |
|
444d0f621
|
713 |
ipcp = ipc_obtain_object_check(ids, id); |
a5f75e7f2
|
714 715 |
if (IS_ERR(ipcp)) { err = PTR_ERR(ipcp); |
7b4cc5d84
|
716 |
goto err; |
a5f75e7f2
|
717 |
} |
a33e67510
|
718 |
audit_ipc_obj(ipcp); |
e816f370c
|
719 720 |
if (cmd == IPC_SET) audit_ipc_set_perm(extra_perm, perm->uid, |
444d0f621
|
721 |
perm->gid, perm->mode); |
414c0708d
|
722 723 |
euid = current_euid(); |
1efdb69b0
|
724 |
if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) || |
b0e77598f
|
725 |
ns_capable(ns->user_ns, CAP_SYS_ADMIN)) |
7b4cc5d84
|
726 727 |
return ipcp; /* successful lookup */ err: |
a5f75e7f2
|
728 729 |
return ERR_PTR(err); } |
c1d7e01d7
|
730 |
#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION |
1da177e4c
|
731 732 733 |
/** |
8001c8581
|
734 735 |
* ipc_parse_version - ipc call version * @cmd: pointer to command |
1da177e4c
|
736 |
* |
8001c8581
|
737 738 739 |
* Return IPC_64 for new style IPC and IPC_OLD for old style IPC. * The @cmd value is turned from an encoding command and version into * just the command code. |
1da177e4c
|
740 |
*/ |
239521f31
|
741 |
int ipc_parse_version(int *cmd) |
1da177e4c
|
742 743 744 745 746 747 748 749 |
{ if (*cmd & IPC_64) { *cmd ^= IPC_64; return IPC_64; } else { return IPC_OLD; } } |
c1d7e01d7
|
750 |
#endif /* CONFIG_ARCH_WANT_IPC_PARSE_VERSION */ |
ae7817745
|
751 752 |
#ifdef CONFIG_PROC_FS |
bc1fc6d88
|
753 754 755 756 |
struct ipc_proc_iter { struct ipc_namespace *ns; struct ipc_proc_iface *iface; }; |
7ca7e564e
|
757 758 759 |
/* * This routine locks the ipc structure found at least at position pos. */ |
b524b9adb
|
760 761 |
static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos, loff_t *new_pos) |
ae7817745
|
762 |
{ |
7ca7e564e
|
763 764 |
struct kern_ipc_perm *ipc; int total, id; |
73ea41302
|
765 |
|
7ca7e564e
|
766 767 768 769 770 771 |
total = 0; for (id = 0; id < pos && total < ids->in_use; id++) { ipc = idr_find(&ids->ipcs_idr, id); if (ipc != NULL) total++; } |
ae7817745
|
772 |
|
7ca7e564e
|
773 774 |
if (total >= ids->in_use) return NULL; |
ae7817745
|
775 |
|
239521f31
|
776 |
for (; pos < IPCMNI; pos++) { |
7ca7e564e
|
777 778 779 |
ipc = idr_find(&ids->ipcs_idr, pos); if (ipc != NULL) { *new_pos = pos + 1; |
32a275001
|
780 781 |
rcu_read_lock(); ipc_lock_object(ipc); |
ae7817745
|
782 783 784 785 786 787 788 |
return ipc; } } /* Out of range - return NULL to terminate iteration */ return NULL; } |
7ca7e564e
|
789 790 791 792 793 794 795 796 797 |
static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos) { struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; struct kern_ipc_perm *ipc = it; /* If we had an ipc id locked before, unlock it */ if (ipc && ipc != SEQ_START_TOKEN) ipc_unlock(ipc); |
ed2ddbf88
|
798 |
return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos); |
7ca7e564e
|
799 |
} |
ae7817745
|
800 |
/* |
f4566f048
|
801 802 |
* File positions: pos 0 -> header, pos n -> ipc id = n - 1. * SeqFile iterator: iterator value locked ipc pointer or SEQ_TOKEN_START. |
ae7817745
|
803 804 805 |
*/ static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos) { |
bc1fc6d88
|
806 807 |
struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; |
73ea41302
|
808 |
struct ipc_ids *ids; |
ed2ddbf88
|
809 |
ids = &iter->ns->ids[iface->ids]; |
ae7817745
|
810 811 812 813 814 |
/* * Take the lock - this will be released by the corresponding * call to stop(). */ |
d9a605e40
|
815 |
down_read(&ids->rwsem); |
ae7817745
|
816 817 818 819 820 821 822 823 824 825 |
/* pos < 0 is invalid */ if (*pos < 0) return NULL; /* pos == 0 means header */ if (*pos == 0) return SEQ_START_TOKEN; /* Find the (pos-1)th ipc */ |
7ca7e564e
|
826 |
return sysvipc_find_ipc(ids, *pos - 1, pos); |
ae7817745
|
827 828 829 830 831 |
} static void sysvipc_proc_stop(struct seq_file *s, void *it) { struct kern_ipc_perm *ipc = it; |
bc1fc6d88
|
832 833 |
struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; |
73ea41302
|
834 |
struct ipc_ids *ids; |
ae7817745
|
835 |
|
f4566f048
|
836 |
/* If we had a locked structure, release it */ |
ae7817745
|
837 838 |
if (ipc && ipc != SEQ_START_TOKEN) ipc_unlock(ipc); |
ed2ddbf88
|
839 |
ids = &iter->ns->ids[iface->ids]; |
ae7817745
|
840 |
/* Release the lock we took in start() */ |
d9a605e40
|
841 |
up_read(&ids->rwsem); |
ae7817745
|
842 843 844 845 |
} static int sysvipc_proc_show(struct seq_file *s, void *it) { |
bc1fc6d88
|
846 847 |
struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; |
ae7817745
|
848 849 850 851 852 853 |
if (it == SEQ_START_TOKEN) return seq_puts(s, iface->header); return iface->show(s, it); } |
88e9d34c7
|
854 |
static const struct seq_operations sysvipc_proc_seqops = { |
ae7817745
|
855 856 857 858 859 |
.start = sysvipc_proc_start, .stop = sysvipc_proc_stop, .next = sysvipc_proc_next, .show = sysvipc_proc_show, }; |
bc1fc6d88
|
860 861 |
static int sysvipc_proc_open(struct inode *inode, struct file *file) { |
bc1fc6d88
|
862 |
struct ipc_proc_iter *iter; |
d66a0520c
|
863 |
iter = __seq_open_private(file, &sysvipc_proc_seqops, sizeof(*iter)); |
bc1fc6d88
|
864 |
if (!iter) |
d66a0520c
|
865 |
return -ENOMEM; |
bc1fc6d88
|
866 |
|
d9dda78ba
|
867 |
iter->iface = PDE_DATA(inode); |
bc1fc6d88
|
868 |
iter->ns = get_ipc_ns(current->nsproxy->ipc_ns); |
d66a0520c
|
869 870 |
return 0; |
bc1fc6d88
|
871 872 873 874 875 876 877 878 |
} static int sysvipc_proc_release(struct inode *inode, struct file *file) { struct seq_file *seq = file->private_data; struct ipc_proc_iter *iter = seq->private; put_ipc_ns(iter->ns); return seq_release_private(inode, file); |
ae7817745
|
879 |
} |
9a32144e9
|
880 |
static const struct file_operations sysvipc_proc_fops = { |
ae7817745
|
881 882 883 |
.open = sysvipc_proc_open, .read = seq_read, .llseek = seq_lseek, |
bc1fc6d88
|
884 |
.release = sysvipc_proc_release, |
ae7817745
|
885 886 |
}; #endif /* CONFIG_PROC_FS */ |