diff options
Diffstat (limited to 'ANDROID_3.4.5/ipc/util.c')
| -rw-r--r-- | ANDROID_3.4.5/ipc/util.c | 987 |
1 files changed, 0 insertions, 987 deletions
diff --git a/ANDROID_3.4.5/ipc/util.c b/ANDROID_3.4.5/ipc/util.c deleted file mode 100644 index 75261a31..00000000 --- a/ANDROID_3.4.5/ipc/util.c +++ /dev/null @@ -1,987 +0,0 @@ -/* - * 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> - */ - -#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/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 <asm/unistd.h> - -#include "util.h" - -struct ipc_proc_iface { - const char *path; - const char *header; - int ids; - int (*show)(struct seq_file *, void *); -}; - -#ifdef CONFIG_MEMORY_HOTPLUG - -static void ipc_memory_notifier(struct work_struct *work) -{ - ipcns_notify(IPCNS_MEMCHANGED); -} - -static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier); - - -static int ipc_memory_callback(struct notifier_block *self, - unsigned long action, void *arg) -{ - 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. - * 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. - * No need to keep several ipc work items on the queue. - */ - if (!work_pending(&ipc_memory_wq)) - schedule_work(&ipc_memory_wq); - break; - case MEM_GOING_ONLINE: - case MEM_GOING_OFFLINE: - case MEM_CANCEL_ONLINE: - case MEM_CANCEL_OFFLINE: - default: - break; - } - - return NOTIFY_OK; -} - -#endif /* CONFIG_MEMORY_HOTPLUG */ - -/** - * ipc_init - initialise IPC subsystem - * - * The various system5 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) -{ - sem_init(); - msg_init(); - shm_init(); - hotplug_memory_notifier(ipc_memory_callback, IPC_CALLBACK_PRI); - register_ipcns_notifier(&init_ipc_ns); - return 0; -} -__initcall(ipc_init); - -/** - * ipc_init_ids - initialise IPC identifiers - * @ids: Identifier set - * - * Set up the sequence range to use for the ipc identifier range (limited - * below IPCMNI) then initialise the ids idr. - */ - -void ipc_init_ids(struct ipc_ids *ids) -{ - init_rwsem(&ids->rw_mutex); - - ids->in_use = 0; - ids->seq = 0; - { - int seq_limit = INT_MAX/SEQ_MULTIPLIER; - if (seq_limit > USHRT_MAX) - ids->seq_max = USHRT_MAX; - else - ids->seq_max = seq_limit; - } - - idr_init(&ids->ipcs_idr); -} - -#ifdef CONFIG_PROC_FS -static const struct file_operations sysvipc_proc_fops; -/** - * 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(sizeof(*iface), GFP_KERNEL); - 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_fops, - iface); - if (!pde) { - kfree(iface); - } -} -#endif - -/** - * ipc_findkey - find a key in an ipc identifier set - * @ids: Identifier set - * @key: The key to find - * - * Requires ipc_ids.rw_mutex locked. - * Returns the LOCKED pointer to the ipc structure if found or NULL - * if not. - * If key is found ipc points to the owning ipc structure - */ - -static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key) -{ - struct kern_ipc_perm *ipc; - int next_id; - int total; - - for (total = 0, next_id = 0; total < ids->in_use; next_id++) { - ipc = idr_find(&ids->ipcs_idr, next_id); - - if (ipc == NULL) - continue; - - if (ipc->key != key) { - total++; - continue; - } - - ipc_lock_by_ptr(ipc); - return ipc; - } - - return NULL; -} - -/** - * ipc_get_maxid - get the last assigned id - * @ids: IPC identifier set - * - * Called with ipc_ids.rw_mutex held. - */ - -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; - - 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; -} - -/** - * ipc_addid - add an IPC identifier - * @ids: IPC identifier set - * @new: new IPC permission set - * @size: 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 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. - * - * Called with ipc_ids.rw_mutex held as a writer. - */ - -int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) -{ - uid_t euid; - gid_t egid; - int id, err; - - if (size > IPCMNI) - size = IPCMNI; - - if (ids->in_use >= size) - return -ENOSPC; - - spin_lock_init(&new->lock); - new->deleted = 0; - rcu_read_lock(); - spin_lock(&new->lock); - - err = idr_get_new(&ids->ipcs_idr, new, &id); - if (err) { - spin_unlock(&new->lock); - rcu_read_unlock(); - return err; - } - - ids->in_use++; - - current_euid_egid(&euid, &egid); - new->cuid = new->uid = euid; - new->gid = new->cgid = egid; - - new->seq = ids->seq++; - if(ids->seq > ids->seq_max) - ids->seq = 0; - - new->id = ipc_buildid(id, new->seq); - return id; -} - -/** - * ipcget_new - create a new ipc object - * @ns: namespace - * @ids: IPC identifer 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, - struct ipc_ops *ops, struct ipc_params *params) -{ - int err; -retry: - err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL); - - if (!err) - return -ENOMEM; - - down_write(&ids->rw_mutex); - err = ops->getnew(ns, params); - up_write(&ids->rw_mutex); - - if (err == -EAGAIN) - goto retry; - - return err; -} - -/** - * ipc_check_perms - check security and permissions for an IPC - * @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 - * ids IDR. - * - * On success, the IPC id is returned. - * - * It is called with ipc_ids.rw_mutex and ipcp->lock held. - */ -static int ipc_check_perms(struct ipc_namespace *ns, - struct kern_ipc_perm *ipcp, - 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: namespace - * @ids: IPC identifer 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, - struct ipc_ops *ops, struct ipc_params *params) -{ - struct kern_ipc_perm *ipcp; - int flg = params->flg; - int err; -retry: - err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL); - - /* - * Take the lock as a writer since we are potentially going to add - * a new entry + read locks are not "upgradable" - */ - down_write(&ids->rw_mutex); - ipcp = ipc_findkey(ids, params->key); - if (ipcp == NULL) { - /* key not used */ - if (!(flg & IPC_CREAT)) - err = -ENOENT; - else if (!err) - err = -ENOMEM; - 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->rw_mutex); - - if (err == -EAGAIN) - goto retry; - - return err; -} - - -/** - * ipc_rmid - remove an IPC identifier - * @ids: IPC identifier set - * @ipcp: ipc perm structure containing the identifier to remove - * - * ipc_ids.rw_mutex (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 lid = ipcid_to_idx(ipcp->id); - - idr_remove(&ids->ipcs_idr, lid); - - ids->in_use--; - - ipcp->deleted = 1; - - return; -} - -/** - * ipc_alloc - allocate ipc space - * @size: size desired - * - * Allocate memory from the appropriate pools and return a pointer to it. - * NULL is returned if the allocation fails - */ - -void* ipc_alloc(int size) -{ - void* out; - if(size > PAGE_SIZE) - out = vmalloc(size); - else - out = kmalloc(size, GFP_KERNEL); - return out; -} - -/** - * ipc_free - free ipc space - * @ptr: pointer returned by ipc_alloc - * @size: size of block - * - * Free a block created with ipc_alloc(). The caller must know the size - * used in the allocation call. - */ - -void ipc_free(void* ptr, int size) -{ - if(size > PAGE_SIZE) - vfree(ptr); - else - kfree(ptr); -} - -/* - * rcu allocations: - * There are three headers that are prepended to the actual allocation: - * - during use: ipc_rcu_hdr. - * - during the rcu grace period: ipc_rcu_grace. - * - [only if vmalloc]: ipc_rcu_sched. - * Their lifetime doesn't overlap, thus the headers share the same memory. - * Unlike a normal union, they are right-aligned, thus some container_of - * forward/backward casting is necessary: - */ -struct ipc_rcu_hdr -{ - int refcount; - int is_vmalloc; - void *data[0]; -}; - - -struct ipc_rcu_grace -{ - struct rcu_head rcu; - /* "void *" makes sure alignment of following data is sane. */ - void *data[0]; -}; - -struct ipc_rcu_sched -{ - struct work_struct work; - /* "void *" makes sure alignment of following data is sane. */ - void *data[0]; -}; - -#define HDRLEN_KMALLOC (sizeof(struct ipc_rcu_grace) > sizeof(struct ipc_rcu_hdr) ? \ - sizeof(struct ipc_rcu_grace) : sizeof(struct ipc_rcu_hdr)) -#define HDRLEN_VMALLOC (sizeof(struct ipc_rcu_sched) > HDRLEN_KMALLOC ? \ - sizeof(struct ipc_rcu_sched) : HDRLEN_KMALLOC) - -static inline int rcu_use_vmalloc(int size) -{ - /* Too big for a single page? */ - if (HDRLEN_KMALLOC + size > PAGE_SIZE) - return 1; - return 0; -} - -/** - * ipc_rcu_alloc - allocate ipc and rcu space - * @size: size desired - * - * Allocate memory for the rcu header structure + the object. - * Returns the pointer to the object. - * NULL is returned if the allocation fails. - */ - -void* ipc_rcu_alloc(int size) -{ - void* out; - /* - * We prepend the allocation with the rcu struct, and - * workqueue if necessary (for vmalloc). - */ - if (rcu_use_vmalloc(size)) { - out = vmalloc(HDRLEN_VMALLOC + size); - if (out) { - out += HDRLEN_VMALLOC; - container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 1; - container_of(out, struct ipc_rcu_hdr, data)->refcount = 1; - } - } else { - out = kmalloc(HDRLEN_KMALLOC + size, GFP_KERNEL); - if (out) { - out += HDRLEN_KMALLOC; - container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 0; - container_of(out, struct ipc_rcu_hdr, data)->refcount = 1; - } - } - - return out; -} - -void ipc_rcu_getref(void *ptr) -{ - container_of(ptr, struct ipc_rcu_hdr, data)->refcount++; -} - -static void ipc_do_vfree(struct work_struct *work) -{ - vfree(container_of(work, struct ipc_rcu_sched, work)); -} - -/** - * ipc_schedule_free - free ipc + rcu space - * @head: RCU callback structure for queued work - * - * Since RCU callback function is called in bh, - * we need to defer the vfree to schedule_work(). - */ -static void ipc_schedule_free(struct rcu_head *head) -{ - struct ipc_rcu_grace *grace; - struct ipc_rcu_sched *sched; - - grace = container_of(head, struct ipc_rcu_grace, rcu); - sched = container_of(&(grace->data[0]), struct ipc_rcu_sched, - data[0]); - - INIT_WORK(&sched->work, ipc_do_vfree); - schedule_work(&sched->work); -} - -void ipc_rcu_putref(void *ptr) -{ - if (--container_of(ptr, struct ipc_rcu_hdr, data)->refcount > 0) - return; - - if (container_of(ptr, struct ipc_rcu_hdr, data)->is_vmalloc) { - call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu, - ipc_schedule_free); - } else { - kfree_rcu(container_of(ptr, struct ipc_rcu_grace, data), rcu); - } -} - -/** - * 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) -{ - uid_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 (euid == ipcp->cuid || - 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 = in->uid; - out->gid = in->gid; - out->cuid = in->cuid; - out->cgid = 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_lock - Lock an ipc structure without rw_mutex held - * @ids: IPC identifier set - * @id: ipc id to look for - * - * Look for an id in the ipc ids idr and lock the associated ipc object. - * - * The ipc object is locked on exit. - */ - -struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id) -{ - struct kern_ipc_perm *out; - int lid = ipcid_to_idx(id); - - rcu_read_lock(); - out = idr_find(&ids->ipcs_idr, lid); - if (out == NULL) { - rcu_read_unlock(); - return ERR_PTR(-EINVAL); - } - - spin_lock(&out->lock); - - /* ipc_rmid() may have already freed the ID while ipc_lock - * was spinning: here verify that the structure is still valid - */ - if (out->deleted) { - spin_unlock(&out->lock); - rcu_read_unlock(); - return ERR_PTR(-EINVAL); - } - - return out; -} - -struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id) -{ - struct kern_ipc_perm *out; - - out = ipc_lock(ids, id); - if (IS_ERR(out)) - return out; - - if (ipc_checkid(out, id)) { - ipc_unlock(out); - return ERR_PTR(-EIDRM); - } - - return out; -} - -/** - * ipcget - Common sys_*get() code - * @ns : namsepace - * @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, - 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. - * @in: the permission given as input. - * @out: the permission of the ipc to set. - */ -void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out) -{ - out->uid = in->uid; - out->gid = in->gid; - out->mode = (out->mode & ~S_IRWXUGO) - | (in->mode & S_IRWXUGO); -} - -/** - * ipcctl_pre_down - retrieve an ipc and check permissions for some IPC_XXX cmd - * @ns: the 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 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 the ipc with both ipc and rw_mutex locks held in case of success - * or an err-code without any lock held otherwise. - */ -struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns, - struct ipc_ids *ids, int id, int cmd, - struct ipc64_perm *perm, int extra_perm) -{ - struct kern_ipc_perm *ipcp; - uid_t euid; - int err; - - down_write(&ids->rw_mutex); - ipcp = ipc_lock_check(ids, id); - if (IS_ERR(ipcp)) { - err = PTR_ERR(ipcp); - goto out_up; - } - - audit_ipc_obj(ipcp); - if (cmd == IPC_SET) - audit_ipc_set_perm(extra_perm, perm->uid, - perm->gid, perm->mode); - - euid = current_euid(); - if (euid == ipcp->cuid || euid == ipcp->uid || - ns_capable(ns->user_ns, CAP_SYS_ADMIN)) - return ipcp; - - err = -EPERM; - ipc_unlock(ipcp); -out_up: - up_write(&ids->rw_mutex); - return ERR_PTR(err); -} - -#ifdef __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 /* __ARCH_WANT_IPC_PARSE_VERSION */ - -#ifdef CONFIG_PROC_FS -struct ipc_proc_iter { - struct ipc_namespace *ns; - struct ipc_proc_iface *iface; -}; - -/* - * This routine locks the ipc structure found at least at position pos. - */ -static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos, - loff_t *new_pos) -{ - struct kern_ipc_perm *ipc; - int total, id; - - total = 0; - for (id = 0; id < pos && total < ids->in_use; id++) { - ipc = idr_find(&ids->ipcs_idr, id); - if (ipc != NULL) - total++; - } - - if (total >= ids->in_use) - return NULL; - - for ( ; pos < IPCMNI; pos++) { - ipc = idr_find(&ids->ipcs_idr, pos); - if (ipc != NULL) { - *new_pos = pos + 1; - ipc_lock_by_ptr(ipc); - return ipc; - } - } - - /* Out of range - return NULL to terminate iteration */ - return NULL; -} - -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); - - return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos); -} - -/* - * File positions: pos 0 -> header, pos n -> ipc id = 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->rw_mutex); - - /* 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 */ - return sysvipc_find_ipc(ids, *pos - 1, 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->rw_mutex); -} - -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) - return seq_puts(s, iface->header); - - 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) -{ - int ret; - struct seq_file *seq; - struct ipc_proc_iter *iter; - - ret = -ENOMEM; - iter = kmalloc(sizeof(*iter), GFP_KERNEL); - if (!iter) - goto out; - - ret = seq_open(file, &sysvipc_proc_seqops); - if (ret) - goto out_kfree; - - seq = file->private_data; - seq->private = iter; - - iter->iface = PDE(inode)->data; - iter->ns = get_ipc_ns(current->nsproxy->ipc_ns); -out: - return ret; -out_kfree: - kfree(iter); - goto out; -} - -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); -} - -static const struct file_operations sysvipc_proc_fops = { - .open = sysvipc_proc_open, - .read = seq_read, - .llseek = seq_lseek, - .release = sysvipc_proc_release, -}; -#endif /* CONFIG_PROC_FS */ |