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ipc/util.c
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// SPDX-License-Identifier: GPL-2.0 |
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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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/** |
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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) { |
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int err_sem, err_msg; err_sem = sem_init(); WARN(err_sem, "ipc: sysv sem_init failed: %d ", err_sem); err_msg = msg_init(); WARN(err_msg, "ipc: sysv msg_init failed: %d ", err_msg); |
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shm_init(); |
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return err_msg ? err_msg : err_sem; |
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} |
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device_initcall(ipc_init); |
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|
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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 = FIELD_SIZEOF(struct kern_ipc_perm, key), .locks_mul = 1, .automatic_shrinking = true, }; |
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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 |
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* below IPCMNI) then initialise the keys hashtable and ids idr. |
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*/ |
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int ipc_init_ids(struct ipc_ids *ids) |
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{ |
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int err; |
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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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err = rhashtable_init(&ids->key_ht, &ipc_kht_params); if (err) return err; |
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idr_init(&ids->ipcs_idr); |
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ids->tables_initialized = true; return 0; |
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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 * |
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* Called with writer 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 *ipcp = NULL; |
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|
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if (likely(ids->tables_initialized)) ipcp = rhashtable_lookup_fast(&ids->key_ht, &key, ipc_kht_params); |
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|
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if (ipcp) { |
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rcu_read_lock(); |
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ipc_lock_object(ipcp); return ipcp; |
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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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|
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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, err; |
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int next_id = ids->next_id; |
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|
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if (size > IPCMNI) size = IPCMNI; |
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if (!ids->tables_initialized || 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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refcount_set(&new->refcount, 1); |
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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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current_euid_egid(&euid, &egid); new->cuid = new->uid = euid; new->gid = new->cgid = egid; |
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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(); |
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if (id >= 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, id); id = err; } } |
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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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|
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ids->in_use++; |
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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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|
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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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|
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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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|
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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_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) rhashtable_remove_fast(&ids->key_ht, &ipcp->khtnode, ipc_kht_params); } |
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/** |
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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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ipc_kht_remove(ids, ipcp); |
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ids->in_use--; |
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ipcp->deleted = true; |
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} |
0cfb6aee7 ipc: optimize sem... |
421 422 423 424 425 426 427 428 429 430 431 432 433 |
/** * 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; } |
dba4cdd39 ipc: merge ipc_rc... |
434 |
int ipc_rcu_getref(struct kern_ipc_perm *ptr) |
1da177e4c Linux-2.6.12-rc2 |
435 |
{ |
9405c03ee ipc: convert kern... |
436 |
return refcount_inc_not_zero(&ptr->refcount); |
65f27f384 WorkStruct: Pass ... |
437 |
} |
dba4cdd39 ipc: merge ipc_rc... |
438 439 |
void ipc_rcu_putref(struct kern_ipc_perm *ptr, void (*func)(struct rcu_head *head)) |
1da177e4c Linux-2.6.12-rc2 |
440 |
{ |
9405c03ee ipc: convert kern... |
441 |
if (!refcount_dec_and_test(&ptr->refcount)) |
1da177e4c Linux-2.6.12-rc2 |
442 |
return; |
dba4cdd39 ipc: merge ipc_rc... |
443 |
call_rcu(&ptr->rcu, func); |
53dad6d3a ipc: fix race wit... |
444 |
} |
1da177e4c Linux-2.6.12-rc2 |
445 |
/** |
8001c8581 ipc: standardize ... |
446 447 448 449 |
* ipcperms - check ipc permissions * @ns: ipc namespace * @ipcp: ipc permission set * @flag: desired permission set |
1da177e4c Linux-2.6.12-rc2 |
450 |
* |
8001c8581 ipc: standardize ... |
451 452 |
* Check user, group, other permissions for access * to ipc resources. return 0 if allowed |
b0e77598f userns: user name... |
453 |
* |
0e056eb55 kernel-api.rst: f... |
454 |
* @flag will most probably be 0 or ``S_...UGO`` from <linux/stat.h> |
1da177e4c Linux-2.6.12-rc2 |
455 |
*/ |
b0e77598f userns: user name... |
456 457 |
int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag) { |
1efdb69b0 userns: Convert i... |
458 |
kuid_t euid = current_euid(); |
a33e67510 sanitize audit_ip... |
459 |
int requested_mode, granted_mode; |
1da177e4c Linux-2.6.12-rc2 |
460 |
|
a33e67510 sanitize audit_ip... |
461 |
audit_ipc_obj(ipcp); |
1da177e4c Linux-2.6.12-rc2 |
462 463 |
requested_mode = (flag >> 6) | (flag >> 3) | flag; granted_mode = ipcp->mode; |
1efdb69b0 userns: Convert i... |
464 465 |
if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid)) |
1da177e4c Linux-2.6.12-rc2 |
466 467 468 469 |
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 ipc, kernel: clea... |
470 |
if ((requested_mode & ~granted_mode & 0007) && |
b0e77598f userns: user name... |
471 |
!ns_capable(ns->user_ns, CAP_IPC_OWNER)) |
1da177e4c Linux-2.6.12-rc2 |
472 473 474 475 476 477 478 479 480 481 482 |
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 ipc: standardize ... |
483 484 485 |
* kernel_to_ipc64_perm - convert kernel ipc permissions to user * @in: kernel permissions * @out: new style ipc permissions |
1da177e4c Linux-2.6.12-rc2 |
486 |
* |
8001c8581 ipc: standardize ... |
487 488 |
* Turn the kernel object @in into a set of permissions descriptions * for returning to userspace (@out). |
1da177e4c Linux-2.6.12-rc2 |
489 |
*/ |
239521f31 ipc: whitespace c... |
490 |
void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out) |
1da177e4c Linux-2.6.12-rc2 |
491 492 |
{ out->key = in->key; |
1efdb69b0 userns: Convert i... |
493 494 495 496 |
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 Linux-2.6.12-rc2 |
497 498 499 500 501 |
out->mode = in->mode; out->seq = in->seq; } /** |
8001c8581 ipc: standardize ... |
502 503 504 |
* ipc64_perm_to_ipc_perm - convert new ipc permissions to old * @in: new style ipc permissions * @out: old style ipc permissions |
1da177e4c Linux-2.6.12-rc2 |
505 |
* |
8001c8581 ipc: standardize ... |
506 507 |
* Turn the new style permissions object @in into a compatibility * object and store it into the @out pointer. |
1da177e4c Linux-2.6.12-rc2 |
508 |
*/ |
239521f31 ipc: whitespace c... |
509 |
void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out) |
1da177e4c Linux-2.6.12-rc2 |
510 511 512 513 514 515 516 517 518 |
{ 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 ipc: fix wrong co... |
519 |
/** |
0cfb6aee7 ipc: optimize sem... |
520 |
* ipc_obtain_object_idr |
4d2bff5eb ipc: introduce ob... |
521 522 523 524 525 526 527 528 |
* @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. */ |
55b7ae501 ipc: rename ipc_o... |
529 |
struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id) |
4d2bff5eb ipc: introduce ob... |
530 531 532 |
{ struct kern_ipc_perm *out; int lid = ipcid_to_idx(id); |
0cfb6aee7 ipc: optimize sem... |
533 534 |
if (unlikely(!ids->tables_initialized)) return ERR_PTR(-EINVAL); |
4d2bff5eb ipc: introduce ob... |
535 536 537 538 539 540 541 542 |
out = idr_find(&ids->ipcs_idr, lid); if (!out) return ERR_PTR(-EINVAL); return out; } /** |
8001c8581 ipc: standardize ... |
543 544 |
* ipc_lock - lock an ipc structure without rwsem held * @ids: ipc identifier set |
f4566f048 ipc: fix wrong co... |
545 546 547 548 |
* @id: ipc id to look for * * Look for an id in the ipc ids idr and lock the associated ipc object. * |
4d2bff5eb ipc: introduce ob... |
549 |
* The ipc object is locked on successful exit. |
f4566f048 ipc: fix wrong co... |
550 |
*/ |
7ca7e564e ipc: store ipcs i... |
551 |
struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id) |
1da177e4c Linux-2.6.12-rc2 |
552 |
{ |
7ca7e564e ipc: store ipcs i... |
553 |
struct kern_ipc_perm *out; |
1da177e4c Linux-2.6.12-rc2 |
554 555 |
rcu_read_lock(); |
55b7ae501 ipc: rename ipc_o... |
556 |
out = ipc_obtain_object_idr(ids, id); |
4d2bff5eb ipc: introduce ob... |
557 |
if (IS_ERR(out)) |
f8b591849 ipc,sysv: make re... |
558 |
goto err; |
7ca7e564e ipc: store ipcs i... |
559 |
|
1da177e4c Linux-2.6.12-rc2 |
560 |
spin_lock(&out->lock); |
4d2bff5eb ipc: introduce ob... |
561 |
|
f8b591849 ipc,sysv: make re... |
562 563 564 565 566 |
/* * ipc_rmid() may have already freed the ID while ipc_lock() * was spinning: here verify that the structure is still valid. * Upon races with RMID, return -EIDRM, thus indicating that * the ID points to a removed identifier. |
1da177e4c Linux-2.6.12-rc2 |
567 |
*/ |
72a8ff2f9 ipc: change kern_... |
568 |
if (ipc_valid_object(out)) |
4d2bff5eb ipc: introduce ob... |
569 570 571 |
return out; spin_unlock(&out->lock); |
f8b591849 ipc,sysv: make re... |
572 573 |
out = ERR_PTR(-EIDRM); err: |
4d2bff5eb ipc: introduce ob... |
574 575 576 |
rcu_read_unlock(); return out; } |
7ca7e564e ipc: store ipcs i... |
577 |
|
4d2bff5eb ipc: introduce ob... |
578 579 580 581 582 |
/** * ipc_obtain_object_check * @ids: ipc identifier set * @id: ipc id to look for * |
55b7ae501 ipc: rename ipc_o... |
583 |
* Similar to ipc_obtain_object_idr() but also checks |
4d2bff5eb ipc: introduce ob... |
584 585 586 587 588 589 590 |
* 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) { |
55b7ae501 ipc: rename ipc_o... |
591 |
struct kern_ipc_perm *out = ipc_obtain_object_idr(ids, id); |
4d2bff5eb ipc: introduce ob... |
592 593 594 595 596 |
if (IS_ERR(out)) goto out; if (ipc_checkid(out, id)) |
6157dbbfb ipc,sysv: return ... |
597 |
return ERR_PTR(-EINVAL); |
4d2bff5eb ipc: introduce ob... |
598 |
out: |
1da177e4c Linux-2.6.12-rc2 |
599 600 |
return out; } |
b2d75cddc ipc: uninline som... |
601 602 |
/** * ipcget - Common sys_*get() code |
da3dae54e Documentation: Do... |
603 |
* @ns: namespace |
8001c8581 ipc: standardize ... |
604 605 606 607 |
* @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 ipc: uninline som... |
608 609 610 611 |
* * Common routine called by sys_msgget(), sys_semget() and sys_shmget(). */ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, |
eb66ec44f ipc: constify ipc... |
612 |
const struct ipc_ops *ops, struct ipc_params *params) |
b2d75cddc ipc: uninline som... |
613 614 615 616 617 618 |
{ if (params->key == IPC_PRIVATE) return ipcget_new(ns, ids, ops, params); else return ipcget_public(ns, ids, ops, params); } |
8f4a3809c IPC: introduce ip... |
619 |
/** |
8001c8581 ipc: standardize ... |
620 |
* ipc_update_perm - update the permissions of an ipc object |
8f4a3809c IPC: introduce ip... |
621 622 623 |
* @in: the permission given as input. * @out: the permission of the ipc to set. */ |
1efdb69b0 userns: Convert i... |
624 |
int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out) |
8f4a3809c IPC: introduce ip... |
625 |
{ |
1efdb69b0 userns: Convert i... |
626 627 628 629 630 631 632 |
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 IPC: introduce ip... |
633 634 |
out->mode = (out->mode & ~S_IRWXUGO) | (in->mode & S_IRWXUGO); |
1efdb69b0 userns: Convert i... |
635 636 |
return 0; |
8f4a3809c IPC: introduce ip... |
637 |
} |
a5f75e7f2 IPC: consolidate ... |
638 |
/** |
3b1c4ad37 ipc: drop ipcctl_... |
639 |
* ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd |
8001c8581 ipc: standardize ... |
640 |
* @ns: ipc namespace |
a5f75e7f2 IPC: consolidate ... |
641 642 643 644 645 646 647 648 |
* @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. |
0e056eb55 kernel-api.rst: f... |
649 650 651 652 653 654 |
* 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 * - returns a pointer to the ipc object or otherwise, the corresponding * error. |
7b4cc5d84 ipc: move locking... |
655 |
* |
d9a605e40 ipc: rename ids->... |
656 |
* Call holding the both the rwsem and the rcu read lock. |
a5f75e7f2 IPC: consolidate ... |
657 |
*/ |
444d0f621 ipc: introduce lo... |
658 |
struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns, |
3b1c4ad37 ipc: drop ipcctl_... |
659 660 |
struct ipc_ids *ids, int id, int cmd, struct ipc64_perm *perm, int extra_perm) |
444d0f621 ipc: introduce lo... |
661 |
{ |
1efdb69b0 userns: Convert i... |
662 |
kuid_t euid; |
444d0f621 ipc: introduce lo... |
663 664 |
int err = -EPERM; struct kern_ipc_perm *ipcp; |
a5f75e7f2 IPC: consolidate ... |
665 |
|
444d0f621 ipc: introduce lo... |
666 |
ipcp = ipc_obtain_object_check(ids, id); |
a5f75e7f2 IPC: consolidate ... |
667 668 |
if (IS_ERR(ipcp)) { err = PTR_ERR(ipcp); |
7b4cc5d84 ipc: move locking... |
669 |
goto err; |
a5f75e7f2 IPC: consolidate ... |
670 |
} |
a33e67510 sanitize audit_ip... |
671 |
audit_ipc_obj(ipcp); |
e816f370c sanitize audit_ip... |
672 673 |
if (cmd == IPC_SET) audit_ipc_set_perm(extra_perm, perm->uid, |
444d0f621 ipc: introduce lo... |
674 |
perm->gid, perm->mode); |
414c0708d CRED: Wrap task c... |
675 676 |
euid = current_euid(); |
1efdb69b0 userns: Convert i... |
677 |
if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) || |
b0e77598f userns: user name... |
678 |
ns_capable(ns->user_ns, CAP_SYS_ADMIN)) |
7b4cc5d84 ipc: move locking... |
679 680 |
return ipcp; /* successful lookup */ err: |
a5f75e7f2 IPC: consolidate ... |
681 682 |
return ERR_PTR(err); } |
c1d7e01d7 ipc: use Kconfig ... |
683 |
#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION |
1da177e4c Linux-2.6.12-rc2 |
684 685 686 |
/** |
8001c8581 ipc: standardize ... |
687 688 |
* ipc_parse_version - ipc call version * @cmd: pointer to command |
1da177e4c Linux-2.6.12-rc2 |
689 |
* |
8001c8581 ipc: standardize ... |
690 691 692 |
* 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 Linux-2.6.12-rc2 |
693 |
*/ |
239521f31 ipc: whitespace c... |
694 |
int ipc_parse_version(int *cmd) |
1da177e4c Linux-2.6.12-rc2 |
695 696 697 698 699 700 701 702 |
{ if (*cmd & IPC_64) { *cmd ^= IPC_64; return IPC_64; } else { return IPC_OLD; } } |
c1d7e01d7 ipc: use Kconfig ... |
703 |
#endif /* CONFIG_ARCH_WANT_IPC_PARSE_VERSION */ |
ae7817745 [PATCH] ipc: add ... |
704 705 |
#ifdef CONFIG_PROC_FS |
bc1fc6d88 [PATCH] ipc: save... |
706 707 708 709 |
struct ipc_proc_iter { struct ipc_namespace *ns; struct ipc_proc_iface *iface; }; |
7ca7e564e ipc: store ipcs i... |
710 711 712 |
/* * This routine locks the ipc structure found at least at position pos. */ |
b524b9adb make ipc/util.c:s... |
713 714 |
static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos, loff_t *new_pos) |
ae7817745 [PATCH] ipc: add ... |
715 |
{ |
7ca7e564e ipc: store ipcs i... |
716 717 |
struct kern_ipc_perm *ipc; int total, id; |
73ea41302 [PATCH] IPC names... |
718 |
|
7ca7e564e ipc: store ipcs i... |
719 720 721 722 723 724 |
total = 0; for (id = 0; id < pos && total < ids->in_use; id++) { ipc = idr_find(&ids->ipcs_idr, id); if (ipc != NULL) total++; } |
ae7817745 [PATCH] ipc: add ... |
725 |
|
7ca7e564e ipc: store ipcs i... |
726 727 |
if (total >= ids->in_use) return NULL; |
ae7817745 [PATCH] ipc: add ... |
728 |
|
239521f31 ipc: whitespace c... |
729 |
for (; pos < IPCMNI; pos++) { |
7ca7e564e ipc: store ipcs i... |
730 731 732 |
ipc = idr_find(&ids->ipcs_idr, pos); if (ipc != NULL) { *new_pos = pos + 1; |
32a275001 ipc: drop ipc_loc... |
733 734 |
rcu_read_lock(); ipc_lock_object(ipc); |
ae7817745 [PATCH] ipc: add ... |
735 736 737 738 739 740 741 |
return ipc; } } /* Out of range - return NULL to terminate iteration */ return NULL; } |
7ca7e564e ipc: store ipcs i... |
742 743 744 745 746 747 748 749 750 |
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 IPC: make struct ... |
751 |
return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos); |
7ca7e564e ipc: store ipcs i... |
752 |
} |
ae7817745 [PATCH] ipc: add ... |
753 |
/* |
f4566f048 ipc: fix wrong co... |
754 755 |
* File positions: pos 0 -> header, pos n -> ipc id = n - 1. * SeqFile iterator: iterator value locked ipc pointer or SEQ_TOKEN_START. |
ae7817745 [PATCH] ipc: add ... |
756 757 758 |
*/ static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos) { |
bc1fc6d88 [PATCH] ipc: save... |
759 760 |
struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; |
73ea41302 [PATCH] IPC names... |
761 |
struct ipc_ids *ids; |
ed2ddbf88 IPC: make struct ... |
762 |
ids = &iter->ns->ids[iface->ids]; |
ae7817745 [PATCH] ipc: add ... |
763 764 765 766 767 |
/* * Take the lock - this will be released by the corresponding * call to stop(). */ |
d9a605e40 ipc: rename ids->... |
768 |
down_read(&ids->rwsem); |
ae7817745 [PATCH] ipc: add ... |
769 770 771 772 773 774 775 776 777 778 |
/* 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 ipc: store ipcs i... |
779 |
return sysvipc_find_ipc(ids, *pos - 1, pos); |
ae7817745 [PATCH] ipc: add ... |
780 781 782 783 784 |
} static void sysvipc_proc_stop(struct seq_file *s, void *it) { struct kern_ipc_perm *ipc = it; |
bc1fc6d88 [PATCH] ipc: save... |
785 786 |
struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; |
73ea41302 [PATCH] IPC names... |
787 |
struct ipc_ids *ids; |
ae7817745 [PATCH] ipc: add ... |
788 |
|
f4566f048 ipc: fix wrong co... |
789 |
/* If we had a locked structure, release it */ |
ae7817745 [PATCH] ipc: add ... |
790 791 |
if (ipc && ipc != SEQ_START_TOKEN) ipc_unlock(ipc); |
ed2ddbf88 IPC: make struct ... |
792 |
ids = &iter->ns->ids[iface->ids]; |
ae7817745 [PATCH] ipc: add ... |
793 |
/* Release the lock we took in start() */ |
d9a605e40 ipc: rename ids->... |
794 |
up_read(&ids->rwsem); |
ae7817745 [PATCH] ipc: add ... |
795 796 797 798 |
} static int sysvipc_proc_show(struct seq_file *s, void *it) { |
bc1fc6d88 [PATCH] ipc: save... |
799 800 |
struct ipc_proc_iter *iter = s->private; struct ipc_proc_iface *iface = iter->iface; |
ae7817745 [PATCH] ipc: add ... |
801 |
|
7f032d6ef ipc: remove use o... |
802 803 804 805 |
if (it == SEQ_START_TOKEN) { seq_puts(s, iface->header); return 0; } |
ae7817745 [PATCH] ipc: add ... |
806 807 808 |
return iface->show(s, it); } |
88e9d34c7 seq_file: constif... |
809 |
static const struct seq_operations sysvipc_proc_seqops = { |
ae7817745 [PATCH] ipc: add ... |
810 811 812 813 814 |
.start = sysvipc_proc_start, .stop = sysvipc_proc_stop, .next = sysvipc_proc_next, .show = sysvipc_proc_show, }; |
bc1fc6d88 [PATCH] ipc: save... |
815 816 |
static int sysvipc_proc_open(struct inode *inode, struct file *file) { |
bc1fc6d88 [PATCH] ipc: save... |
817 |
struct ipc_proc_iter *iter; |
d66a0520c ipc/util.c: use _... |
818 |
iter = __seq_open_private(file, &sysvipc_proc_seqops, sizeof(*iter)); |
bc1fc6d88 [PATCH] ipc: save... |
819 |
if (!iter) |
d66a0520c ipc/util.c: use _... |
820 |
return -ENOMEM; |
bc1fc6d88 [PATCH] ipc: save... |
821 |
|
d9dda78ba procfs: new helpe... |
822 |
iter->iface = PDE_DATA(inode); |
bc1fc6d88 [PATCH] ipc: save... |
823 |
iter->ns = get_ipc_ns(current->nsproxy->ipc_ns); |
d66a0520c ipc/util.c: use _... |
824 825 |
return 0; |
bc1fc6d88 [PATCH] ipc: save... |
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} 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); |
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} |
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static const struct file_operations sysvipc_proc_fops = { |
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.open = sysvipc_proc_open, .read = seq_read, .llseek = seq_lseek, |
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.release = sysvipc_proc_release, |
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}; #endif /* CONFIG_PROC_FS */ |