// SPDX-License-Identifier: GPL-2.0 /* * 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 * Manfred Spraul <manfred@colorfullife.com> * Oct 2002 - One lock per IPC id. RCU ipc_free for lock-free grow_ary(). * Mingming Cao <cmm@us.ibm.com> * Mar 2006 - support for audit of ipc object properties * Dustin Kirkland <dustin.kirkland@us.ibm.com> * Jun 2006 - namespaces ssupport * OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> * * General sysv ipc locking scheme: * 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 INFO command, that * do not demand atomicity * acquire the ipc lock (kern_ipc_perm.lock) through * ipc_lock_object() * - perform read-only operations that demand atomicity, * such as STAT command. * - 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(). */ #include <linux/mm.h> #include <linux/shm.h> #include <linux/init.h> #include <linux/msg.h> #include <linux/vmalloc.h> #include <linux/slab.h> #include <linux/notifier.h> #include <linux/capability.h> #include <linux/highuid.h> #include <linux/security.h> #include <linux/rcupdate.h> #include <linux/workqueue.h> #include <linux/seq_file.h> #include <linux/proc_fs.h> #include <linux/audit.h> #include <linux/nsproxy.h> #include <linux/rwsem.h> #include <linux/memory.h> #include <linux/ipc_namespace.h> #include <linux/rhashtable.h> #include <linux/log2.h> #include <asm/unistd.h> #include "util.h" struct ipc_proc_iface { const char *path; const char *header; int ids; int (*show)(struct seq_file *, void *); }; /** * ipc_init - initialise ipc subsystem * * 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. */ static int __init ipc_init(void) { proc_mkdir("sysvipc", NULL); sem_init(); msg_init(); shm_init(); return 0; } device_initcall(ipc_init); static const struct rhashtable_params ipc_kht_params = { .head_offset = offsetof(struct kern_ipc_perm, khtnode), .key_offset = offsetof(struct kern_ipc_perm, key), .key_len = sizeof_field(struct kern_ipc_perm, key), .automatic_shrinking = true, }; /** * ipc_init_ids - initialise ipc identifiers * @ids: ipc identifier set * * Set up the sequence range to use for the ipc identifier range (limited * below ipc_mni) then initialise the keys hashtable and ids idr. */ void ipc_init_ids(struct ipc_ids *ids) { ids->in_use = 0; ids->seq = 0; init_rwsem(&ids->rwsem); rhashtable_init(&ids->key_ht, &ipc_kht_params); idr_init(&ids->ipcs_idr); ids->max_idx = -1; ids->last_idx = -1; #ifdef CONFIG_CHECKPOINT_RESTORE ids->next_id = -1; #endif } #ifdef CONFIG_PROC_FS static const struct proc_ops sysvipc_proc_ops; /** * 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. */ void __init ipc_init_proc_interface(const char *path, const char *header, int ids, int (*show)(struct seq_file *, void *)) { struct proc_dir_entry *pde; struct ipc_proc_iface *iface; iface = kmalloc_obj(*iface); if (!iface) return; iface->path = path; iface->header = header; iface->ids = ids; iface->show = show; pde = proc_create_data(path, S_IRUGO, /* world readable */ NULL, /* parent dir */ &sysvipc_proc_ops, iface); if (!pde) kfree(iface); } #endif /** * ipc_findkey - find a key in an ipc identifier set * @ids: ipc identifier set * @key: key to find * * 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 writer ipc_ids.rwsem held. */ static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key) { struct kern_ipc_perm *ipcp; ipcp = rhashtable_lookup_fast(&ids->key_ht, &key, ipc_kht_params); if (!ipcp) return NULL; rcu_read_lock(); ipc_lock_object(ipcp); return ipcp; } /* * Insert new IPC object into idr tree, and set sequence number and id * in the correct order. * Especially: * - the sequence number must be set before inserting the object into the idr, * because the sequence number is accessed without a lock. * - the id can/must be set after inserting the object into the idr. * All accesses must be done after getting kern_ipc_perm.lock. * * The caller must own kern_ipc_perm.lock.of the new object. * On error, the function returns a (negative) error code. * * To conserve sequence number space, especially with extended ipc_mni, * the sequence number is incremented only when the returned ID is less than * the last one. */ static inline int ipc_idr_alloc(struct ipc_ids *ids, struct kern_ipc_perm *new) { int idx, next_id = -1; #ifdef CONFIG_CHECKPOINT_RESTORE next_id = ids->next_id; ids->next_id = -1; #endif /* * As soon as a new object is inserted into the idr, * ipc_obtain_object_idr() or ipc_obtain_object_check() can find it, * and the lockless preparations for ipc operations can start. * This means especially: permission checks, audit calls, allocation * of undo structures, ... * * Thus the object must be fully initialized, and if something fails, * then the full tear-down sequence must be followed. * (i.e.: set new->deleted, reduce refcount, call_rcu()) */ if (next_id < 0) { /* !CHECKPOINT_RESTORE or next_id is unset */ int max_idx; max_idx = max(ids->in_use*3/2, ipc_min_cycle); max_idx = min(max_idx, ipc_mni); /* allocate the idx, with a NULL struct kern_ipc_perm */ idx = idr_alloc_cyclic(&ids->ipcs_idr, NULL, 0, max_idx, GFP_NOWAIT); if (idx >= 0) { /* * idx got allocated successfully. * Now calculate the sequence number and set the * pointer for real. */ if (idx <= ids->last_idx) { ids->seq++; if (ids->seq >= ipcid_seq_max()) ids->seq = 0; } ids->last_idx = idx; new->seq = ids->seq; /* no need for smp_wmb(), this is done * inside idr_replace, as part of * rcu_assign_pointer */ idr_replace(&ids->ipcs_idr, new, idx); } } else { new->seq = ipcid_to_seqx(next_id); idx = idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id), 0, GFP_NOWAIT); } if (idx >= 0) new->id = (new->seq << ipcmni_seq_shift()) + idx; return idx; } /** * ipc_addid - add an ipc identifier * @ids: ipc identifier set * @new: new ipc permission set * @limit: limit for the number of used ids * * Add an entry 'new' to the ipc ids idr. The permissions object is * initialised and the first free entry is set up and the index 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. * The caller must use ipc_rcu_putref() to free the identifier. * * Called with writer ipc_ids.rwsem held. */ int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int limit) { kuid_t euid; kgid_t egid; int idx, err; /* 1) Initialize the refcount so that ipc_rcu_putref works */ refcount_set(&new->refcount, 1); if (limit > ipc_mni) limit = ipc_mni; if (ids->in_use >= limit) return -ENOSPC; idr_preload(GFP_KERNEL); spin_lock_init(&new->lock); rcu_read_lock(); spin_lock(&new->lock); current_euid_egid(&euid, &egid); new->cuid = new->uid = euid; new->gid = new->cgid = egid; new->deleted = false; idx = ipc_idr_alloc(ids, new); idr_preload_end(); if (idx >= 0 && new->key != IPC_PRIVATE) { err = rhashtable_insert_fast(&ids->key_ht, &new->khtnode, ipc_kht_params); if (err < 0) { idr_remove(&ids->ipcs_idr, idx); idx = err; } } if (idx < 0) { new->deleted = true; spin_unlock(&new->lock); rcu_read_unlock(); return idx; } ids->in_use++; if (idx > ids->max_idx) ids->max_idx = idx; return idx; } /** * ipcget_new - create a new ipc object * @ns: ipc namespace * @ids: ipc identifier set * @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. */ static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids, const struct ipc_ops *ops, struct ipc_params *params) { int err; down_write(&ids->rwsem); err = ops->getnew(ns, params); up_write(&ids->rwsem); return err; } /** * 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 * * 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. * * On success, the ipc id is returned. * * It is called with ipc_ids.rwsem and ipcp->lock held. */ static int ipc_check_perms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, const struct ipc_ops *ops, struct ipc_params *params) { int err; if (ipcperms(ns, ipcp, params->flg)) err = -EACCES; else { err = ops->associate(ipcp, params->flg); if (!err) err = ipcp->id; } return err; } /** * ipcget_public - get an ipc object or create a new one * @ns: ipc namespace * @ids: ipc identifier set * @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. */ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids, const struct ipc_ops *ops, struct ipc_params *params) { struct kern_ipc_perm *ipcp; int flg = params->flg; int err; /* * Take the lock as a writer since we are potentially going to add * a new entry + read locks are not "upgradable" */ down_write(&ids->rwsem); ipcp = ipc_findkey(ids, params->key); if (ipcp == NULL) { /* key not used */ if (!(flg & IPC_CREAT)) err = -ENOENT; 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) /* * ipc_check_perms returns the IPC id on * success */ err = ipc_check_perms(ns, ipcp, ops, params); } ipc_unlock(ipcp); } up_write(&ids->rwsem); return err; } /** * ipc_kht_remove - remove an ipc from the key hashtable * @ids: ipc identifier set * @ipcp: ipc perm structure containing the key to remove * * 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. */ static void ipc_kht_remove(struct ipc_ids *ids, struct kern_ipc_perm *ipcp) { if (ipcp->key != IPC_PRIVATE) WARN_ON_ONCE(rhashtable_remove_fast(&ids->key_ht, &ipcp->khtnode, ipc_kht_params)); } /** * ipc_search_maxidx - search for the highest assigned index * @ids: ipc identifier set * @limit: known upper limit for highest assigned index * * The function determines the highest assigned index in @ids. It is intended * to be called when ids->max_idx needs to be updated. * Updating ids->max_idx is necessary when the current highest index ipc * object is deleted. * If no ipc object is allocated, then -1 is returned. * * ipc_ids.rwsem needs to be held by the caller. */ static int ipc_search_maxidx(struct ipc_ids *ids, int limit) { int tmpidx; int i; int retval; i = ilog2(limit+1); retval = 0; for (; i >= 0; i--) { tmpidx = retval | (1<<i); /* * "0" is a possible index value, thus search using * e.g. 15,7,3,1,0 instead of 16,8,4,2,1. */ tmpidx = tmpidx-1; if (idr_get_next(&ids->ipcs_idr, &tmpidx)) retval |= (1<<i); } return retval - 1; } /** * ipc_rmid - remove an ipc identifier * @ids: ipc identifier set * @ipcp: ipc perm structure containing the identifier to remove * * 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. */ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp) { int idx = ipcid_to_idx(ipcp->id); WARN_ON_ONCE(idr_remove(&ids->ipcs_idr, idx) != ipcp); ipc_kht_remove(ids, ipcp); ids->in_use--; ipcp->deleted = true; if (unlikely(idx == ids->max_idx)) { idx = ids->max_idx-1; if (idx >= 0) idx = ipc_search_maxidx(ids, idx); ids->max_idx = idx; } } /** * ipc_set_key_private - switch the key of an existing ipc to IPC_PRIVATE * @ids: ipc identifier set * @ipcp: ipc perm structure containing the key to modify * * 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. */ void ipc_set_key_private(struct ipc_ids *ids, struct kern_ipc_perm *ipcp) { ipc_kht_remove(ids, ipcp); ipcp->key = IPC_PRIVATE; } bool ipc_rcu_getref(struct kern_ipc_perm *ptr) { return refcount_inc_not_zero(&ptr->refcount); } void ipc_rcu_putref(struct kern_ipc_perm *ptr, void (*func)(struct rcu_head *head)) { if (!refcount_dec_and_test(&ptr->refcount)) return; call_rcu(&ptr->rcu, func); } /** * ipcperms - check ipc permissions * @ns: ipc namespace * @ipcp: ipc permission set * @flag: desired permission set * * Check user, group, other permissions for access * to ipc resources. return 0 if allowed * * @flag will most probably be 0 or ``S_...UGO`` from <linux/stat.h> */ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag) { kuid_t euid = current_euid(); int requested_mode, granted_mode; audit_ipc_obj(ipcp); requested_mode = (flag >> 6) | (flag >> 3) | flag; granted_mode = ipcp->mode; if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid)) 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? */ if ((requested_mode & ~granted_mode & 0007) && !ns_capable(ns->user_ns, CAP_IPC_OWNER)) return -1; return security_ipc_permission(ipcp, flag); } /* * Functions to convert between the kern_ipc_perm structure and the * old/new ipc_perm structures */ /** * kernel_to_ipc64_perm - convert kernel ipc permissions to user * @in: kernel permissions * @out: new style ipc permissions * * Turn the kernel object @in into a set of permissions descriptions * for returning to userspace (@out). */ void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out) { out->key = in->key; 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); out->mode = in->mode; out->seq = in->seq; } /** * ipc64_perm_to_ipc_perm - convert new ipc permissions to old * @in: new style ipc permissions * @out: old style ipc permissions * * Turn the new style permissions object @in into a compatibility * object and store it into the @out pointer. */ void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out) { 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; } /** * ipc_obtain_object_idr - Look for an id in the ipc ids idr and * return associated ipc object. * @ids: ipc identifier set * @id: ipc id to look for * * Call inside the RCU critical section. * The ipc object is *not* locked on exit. */ struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id) { struct kern_ipc_perm *out; int idx = ipcid_to_idx(id); out = idr_find(&ids->ipcs_idr, idx); if (!out) return ERR_PTR(-EINVAL); return out; } /** * ipc_obtain_object_check - Similar to ipc_obtain_object_idr() but * also checks the ipc object sequence number. * @ids: ipc identifier set * @id: ipc id to look for * * 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_idr(ids, id); if (IS_ERR(out)) goto out; if (ipc_checkid(out, id)) return ERR_PTR(-EINVAL); out: return out; } /** * ipcget - Common sys_*get() code * @ns: namespace * @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. * * Common routine called by sys_msgget(), sys_semget() and sys_shmget(). */ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, const 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); } /** * ipc_update_perm - update the permissions of an ipc object * @in: the permission given as input. * @out: the permission of the ipc to set. */ int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out) { 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; out->mode = (out->mode & ~S_IRWXUGO) | (in->mode & S_IRWXUGO); return 0; } /** * ipcctl_obtain_check - retrieve an ipc object and check permissions * @ns: ipc namespace * @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: * - retrieves the ipc object with the given id in the given table. * - performs some audit and permission check, depending on the given cmd * - returns a pointer to the ipc object or otherwise, the corresponding * error. * * Call holding the both the rwsem and the rcu read lock. */ struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns, struct ipc_ids *ids, int id, int cmd, struct ipc64_perm *perm, int extra_perm) { kuid_t euid; int err = -EPERM; struct kern_ipc_perm *ipcp; ipcp = ipc_obtain_object_check(ids, id); if (IS_ERR(ipcp)) { err = PTR_ERR(ipcp); goto err; } audit_ipc_obj(ipcp); if (cmd == IPC_SET) audit_ipc_set_perm(extra_perm, perm->uid, perm->gid, perm->mode); euid = current_euid(); if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) || ns_capable(ns->user_ns, CAP_SYS_ADMIN)) return ipcp; /* successful lookup */ err: return ERR_PTR(err); } #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION /** * ipc_parse_version - ipc call version * @cmd: pointer to command * * 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. */ int ipc_parse_version(int *cmd) { if (*cmd & IPC_64) { *cmd ^= IPC_64; return IPC_64; } else { return IPC_OLD; } } #endif /* CONFIG_ARCH_WANT_IPC_PARSE_VERSION */ #ifdef CONFIG_PROC_FS struct ipc_proc_iter { struct ipc_namespace *ns; struct pid_namespace *pid_ns; struct ipc_proc_iface *iface; }; struct pid_namespace *ipc_seq_pid_ns(struct seq_file *s) { struct ipc_proc_iter *iter = s->private; return iter->pid_ns; } /** * sysvipc_find_ipc - Find and lock the ipc structure based on seq pos * @ids: ipc identifier set * @pos: expected position * * The function finds an ipc structure, based on the sequence file * position @pos. If there is no ipc structure at position @pos, then * the successor is selected. * If a structure is found, then it is locked (both rcu_read_lock() and * ipc_lock_object()) and @pos is set to the position needed to locate * the found ipc structure. * If nothing is found (i.e. EOF), @pos is not modified. * * The function returns the found ipc structure, or NULL at EOF. */ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t *pos) { int tmpidx; struct kern_ipc_perm *ipc; /* convert from position to idr index -> "-1" */ tmpidx = *pos - 1; ipc = idr_get_next(&ids->ipcs_idr, &tmpidx); if (ipc != NULL) { rcu_read_lock(); ipc_lock_object(ipc); /* convert from idr index to position -> "+1" */ *pos = tmpidx + 1; } return ipc; } 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); /* Next -> search for *pos+1 */ (*pos)++; return sysvipc_find_ipc(&iter->ns->ids[iface->ids], pos); } /* * File positions: pos 0 -> header, pos n -> ipc idx = n - 1. * SeqFile iterator: iterator value locked ipc pointer or SEQ_TOKEN_START. */ static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos) { struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; struct ipc_ids *ids; ids = &iter->ns->ids[iface->ids]; /* * Take the lock - this will be released by the corresponding * call to stop(). */ down_read(&ids->rwsem); /* pos < 0 is invalid */ if (*pos < 0) return NULL; /* pos == 0 means header */ if (*pos == 0) return SEQ_START_TOKEN; /* Otherwise return the correct ipc structure */ return sysvipc_find_ipc(ids, pos); } static void sysvipc_proc_stop(struct seq_file *s, void *it) { struct kern_ipc_perm *ipc = it; struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; struct ipc_ids *ids; /* If we had a locked structure, release it */ if (ipc && ipc != SEQ_START_TOKEN) ipc_unlock(ipc); ids = &iter->ns->ids[iface->ids]; /* Release the lock we took in start() */ up_read(&ids->rwsem); } static int sysvipc_proc_show(struct seq_file *s, void *it) { struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; if (it == SEQ_START_TOKEN) { seq_puts(s, iface->header); return 0; } return iface->show(s, it); } static const struct seq_operations sysvipc_proc_seqops = { .start = sysvipc_proc_start, .stop = sysvipc_proc_stop, .next = sysvipc_proc_next, .show = sysvipc_proc_show, }; static int sysvipc_proc_open(struct inode *inode, struct file *file) { struct ipc_proc_iter *iter; iter = __seq_open_private(file, &sysvipc_proc_seqops, sizeof(*iter)); if (!iter) return -ENOMEM; iter->iface = pde_data(inode); iter->ns = get_ipc_ns(current->nsproxy->ipc_ns); iter->pid_ns = get_pid_ns(task_active_pid_ns(current)); return 0; } 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); put_pid_ns(iter->pid_ns); return seq_release_private(inode, file); } static const struct proc_ops sysvipc_proc_ops = { .proc_flags = PROC_ENTRY_PERMANENT, .proc_open = sysvipc_proc_open, .proc_read = seq_read, .proc_lseek = seq_lseek, .proc_release = sysvipc_proc_release, }; #endif /* CONFIG_PROC_FS */
