* 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 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().
*/
#include <linux/mm.h>
int (*show)(struct seq_file *, void *);
};
-static void ipc_memory_notifier(struct work_struct *work)
-{
- ipcns_notify(IPCNS_MEMCHANGED);
-}
-
-static int ipc_memory_callback(struct notifier_block *self,
- unsigned long action, void *arg)
-{
- static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
-
- 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;
-}
-
-static struct notifier_block ipc_memory_nb = {
- .notifier_call = ipc_memory_callback,
- .priority = IPC_CALLBACK_PRI,
-};
-
/**
- * ipc_init - initialise IPC subsystem
+ * 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.
+ * 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)
{
sem_init();
msg_init();
shm_init();
- register_hotmemory_notifier(&ipc_memory_nb);
- register_ipcns_notifier(&init_ipc_ns);
return 0;
}
-__initcall(ipc_init);
+device_initcall(ipc_init);
/**
- * ipc_init_ids - initialise IPC identifiers
- * @ids: Identifier set
+ * ipc_init_ids - initialise ipc identifiers
+ * @ids: ipc identifier set
*
- * Set up the sequence range to use for the ipc identifier range (limited
- * below IPCMNI) then initialise the ids idr.
+ * 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;
ids->next_id = -1;
- {
- int seq_limit = INT_MAX/SEQ_MULTIPLIER;
- if (seq_limit > USHRT_MAX)
- ids->seq_max = USHRT_MAX;
- else
- ids->seq_max = seq_limit;
- }
-
+ init_rwsem(&ids->rwsem);
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.
+ * 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 *))
NULL, /* parent dir */
&sysvipc_proc_fops,
iface);
- if (!pde) {
+ 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
+ * 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 ipc_ids.rwsem held.
*/
-
static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
{
struct kern_ipc_perm *ipc;
continue;
}
- ipc_lock_by_ptr(ipc);
+ rcu_read_lock();
+ ipc_lock_object(ipc);
return ipc;
}
}
/**
- * ipc_get_maxid - get the last assigned id
- * @ids: IPC identifier set
+ * ipc_get_maxid - get the last assigned id
+ * @ids: ipc identifier set
*
- * Called with ipc_ids.rw_mutex held.
+ * Called with ipc_ids.rwsem held.
*/
-
int ipc_get_maxid(struct ipc_ids *ids)
{
struct kern_ipc_perm *ipc;
}
/**
- * ipc_addid - add an IPC identifier
- * @ids: IPC identifier set
- * @new: new IPC permission set
- * @size: limit for the number of used ids
+ * 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.
+ * 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.
+ * Called with writer ipc_ids.rwsem held.
*/
-
-int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
+int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size)
{
kuid_t euid;
kgid_t egid;
idr_preload(GFP_KERNEL);
spin_lock_init(&new->lock);
- new->deleted = 0;
+ new->deleted = false;
rcu_read_lock();
spin_lock(&new->lock);
+ current_euid_egid(&euid, &egid);
+ new->cuid = new->uid = euid;
+ new->gid = new->cgid = egid;
+
id = idr_alloc(&ids->ipcs_idr, new,
(next_id < 0) ? 0 : ipcid_to_idx(next_id), 0,
GFP_NOWAIT);
ids->in_use++;
- current_euid_egid(&euid, &egid);
- new->cuid = new->uid = euid;
- new->gid = new->cgid = egid;
-
if (next_id < 0) {
new->seq = ids->seq++;
- if (ids->seq > ids->seq_max)
+ if (ids->seq > IPCID_SEQ_MAX)
ids->seq = 0;
} else {
new->seq = ipcid_to_seqx(next_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.
+ * 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,
- struct ipc_ops *ops, struct ipc_params *params)
+ const struct ipc_ops *ops, struct ipc_params *params)
{
int err;
- down_write(&ids->rw_mutex);
+ down_write(&ids->rwsem);
err = ops->getnew(ns, params);
- up_write(&ids->rw_mutex);
+ up_write(&ids->rwsem);
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
+ * 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
- * ids IDR.
+ * 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.
+ * On success, the ipc id is returned.
*
- * It is called with ipc_ids.rw_mutex and ipcp->lock held.
+ * 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,
- struct ipc_ops *ops,
+ const struct ipc_ops *ops,
struct ipc_params *params)
{
int 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.
+ * 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,
- struct ipc_ops *ops, struct ipc_params *params)
+ const struct ipc_ops *ops, struct ipc_params *params)
{
struct kern_ipc_perm *ipcp;
int flg = params->flg;
* 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);
+ down_write(&ids->rwsem);
ipcp = ipc_findkey(ids, params->key);
if (ipcp == NULL) {
/* key not used */
}
ipc_unlock(ipcp);
}
- up_write(&ids->rw_mutex);
+ up_write(&ids->rwsem);
return err;
}
/**
- * ipc_rmid - remove an IPC identifier
- * @ids: IPC identifier set
- * @ipcp: ipc perm structure containing the identifier to remove
+ * 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.
+ * 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 lid = ipcid_to_idx(ipcp->id);
idr_remove(&ids->ipcs_idr, lid);
-
ids->in_use--;
-
- ipcp->deleted = 1;
-
- return;
+ ipcp->deleted = true;
}
/**
- * ipc_alloc - allocate ipc space
- * @size: size desired
+ * 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
+ * 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)
+ if (size > PAGE_SIZE)
out = vmalloc(size);
else
out = kmalloc(size, GFP_KERNEL);
}
/**
- * ipc_free - free ipc space
- * @ptr: pointer returned by ipc_alloc
- * @size: size of block
+ * 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.
+ * 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)
+void ipc_free(void *ptr, int size)
{
- if(size > PAGE_SIZE)
+ if (size > PAGE_SIZE)
vfree(ptr);
else
kfree(ptr);
}
-struct ipc_rcu {
- struct rcu_head rcu;
- atomic_t refcount;
- /* "void *" makes sure alignment of following data is sane. */
- void *data[0];
-};
-
/**
- * ipc_rcu_alloc - allocate ipc and rcu space
- * @size: size desired
+ * 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 or NULL upon failure.
+ * Allocate memory for the rcu header structure + the object.
+ * Returns the pointer to the object or NULL upon failure.
*/
void *ipc_rcu_alloc(int size)
{
if (unlikely(!out))
return NULL;
atomic_set(&out->refcount, 1);
- return out->data;
+ return out + 1;
}
int ipc_rcu_getref(void *ptr)
{
- return atomic_inc_not_zero(&container_of(ptr, struct ipc_rcu, data)->refcount);
-}
+ struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
-/**
- * ipc_schedule_free - free ipc + rcu space
- * @head: RCU callback structure for queued work
- */
-static void ipc_schedule_free(struct rcu_head *head)
-{
- vfree(container_of(head, struct ipc_rcu, rcu));
+ return atomic_inc_not_zero(&p->refcount);
}
-void ipc_rcu_putref(void *ptr)
+void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head))
{
- struct ipc_rcu *p = container_of(ptr, struct ipc_rcu, data);
+ struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
if (!atomic_dec_and_test(&p->refcount))
return;
- if (is_vmalloc_addr(ptr)) {
- call_rcu(&p->rcu, ipc_schedule_free);
- } else {
- kfree_rcu(p, rcu);
- }
+ call_rcu(&p->rcu, func);
+}
+
+void ipc_rcu_free(struct rcu_head *head)
+{
+ struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
+
+ kvfree(p);
}
/**
- * ipcperms - check IPC permissions
- * @ns: IPC namespace
- * @ipcp: IPC permission set
- * @flag: desired permission set.
+ * 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
+ * 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>
+ * @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();
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) &&
+ if ((requested_mode & ~granted_mode & 0007) &&
!ns_capable(ns->user_ns, CAP_IPC_OWNER))
return -1;
*/
/**
- * kernel_to_ipc64_perm - convert kernel ipc permissions to user
- * @in: kernel permissions
- * @out: new style IPC permissions
+ * 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).
+ * 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)
+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);
}
/**
- * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
- * @in: new style IPC permissions
- * @out: old style IPC permissions
+ * 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.
+ * 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)
+void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
{
out->key = in->key;
SET_UID(out->uid, in->uid);
* 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 *ipc_obtain_object_idr(struct ipc_ids *ids, int id)
{
struct kern_ipc_perm *out;
int lid = ipcid_to_idx(id);
}
/**
- * ipc_lock - Lock an ipc structure without rw_mutex held
- * @ids: IPC identifier set
+ * ipc_lock - lock an ipc structure without rwsem 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.
struct kern_ipc_perm *out;
rcu_read_lock();
- out = ipc_obtain_object(ids, id);
+ out = ipc_obtain_object_idr(ids, id);
if (IS_ERR(out))
- goto err1;
+ goto err;
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
+ /*
+ * 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.
*/
- if (!out->deleted)
+ if (ipc_valid_object(out))
return out;
spin_unlock(&out->lock);
- out = ERR_PTR(-EINVAL);
-err1:
+ out = ERR_PTR(-EIDRM);
+err:
rcu_read_unlock();
return out;
}
* @ids: ipc identifier set
* @id: ipc id to look for
*
- * Similar to ipc_obtain_object() but also checks
+ * Similar to ipc_obtain_object_idr() but also checks
* the ipc object reference counter.
*
* Call inside the RCU critical section.
*/
struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
{
- struct kern_ipc_perm *out = ipc_obtain_object(ids, 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(-EIDRM);
+ return ERR_PTR(-EINVAL);
out:
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.
+ * @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,
- struct ipc_ops *ops, struct ipc_params *params)
+ const struct ipc_ops *ops, struct ipc_params *params)
{
if (params->key == IPC_PRIVATE)
return ipcget_new(ns, ids, ops, params);
}
/**
- * ipc_update_perm - update the permissions of an IPC.
+ * ipc_update_perm - update the permissions of an ipc object
* @in: the permission given as input.
* @out: the permission of the ipc to set.
*/
}
/**
- * ipcctl_pre_down - retrieve an ipc and check permissions for some IPC_XXX cmd
- * @ns: the ipc namespace
+ * ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd
+ * @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
* 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.
+ * - 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_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;
-
- ipcp = ipcctl_pre_down_nolock(ns, ids, id, cmd, perm, extra_perm);
- if (IS_ERR(ipcp))
- goto out;
-
- spin_lock(&ipcp->lock);
-out:
- return ipcp;
-}
-
struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
- struct ipc_ids *ids, int id, int cmd,
- struct ipc64_perm *perm, int extra_perm)
+ 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;
- down_write(&ids->rw_mutex);
- rcu_read_lock();
-
ipcp = ipc_obtain_object_check(ids, id);
if (IS_ERR(ipcp)) {
err = PTR_ERR(ipcp);
- goto out_up;
+ goto err;
}
audit_ipc_obj(ipcp);
euid = current_euid();
if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
ns_capable(ns->user_ns, CAP_SYS_ADMIN))
- return ipcp;
-
-out_up:
- /*
- * Unsuccessful lookup, unlock and return
- * the corresponding error.
- */
- rcu_read_unlock();
- up_write(&ids->rw_mutex);
-
+ return ipcp; /* successful lookup */
+err:
return ERR_PTR(err);
}
/**
- * ipc_parse_version - IPC call version
- * @cmd: pointer to command
+ * 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.
+ * 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)
+int ipc_parse_version(int *cmd)
{
if (*cmd & IPC_64) {
*cmd ^= IPC_64;
if (total >= ids->in_use)
return NULL;
- for ( ; pos < IPCMNI; pos++) {
+ for (; pos < IPCMNI; pos++) {
ipc = idr_find(&ids->ipcs_idr, pos);
if (ipc != NULL) {
*new_pos = pos + 1;
- ipc_lock_by_ptr(ipc);
+ rcu_read_lock();
+ ipc_lock_object(ipc);
return ipc;
}
}
* Take the lock - this will be released by the corresponding
* call to stop().
*/
- down_read(&ids->rw_mutex);
+ down_read(&ids->rwsem);
/* pos < 0 is invalid */
if (*pos < 0)
ids = &iter->ns->ids[iface->ids];
/* Release the lock we took in start() */
- up_read(&ids->rw_mutex);
+ 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)
- return seq_puts(s, iface->header);
+ if (it == SEQ_START_TOKEN) {
+ seq_puts(s, iface->header);
+ return 0;
+ }
return iface->show(s, it);
}
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);
+ iter = __seq_open_private(file, &sysvipc_proc_seqops, sizeof(*iter));
if (!iter)
- goto out;
-
- ret = seq_open(file, &sysvipc_proc_seqops);
- if (ret)
- goto out_kfree;
-
- seq = file->private_data;
- seq->private = iter;
+ return -ENOMEM;
iter->iface = PDE_DATA(inode);
iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
-out:
- return ret;
-out_kfree:
- kfree(iter);
- goto out;
+
+ return 0;
}
static int sysvipc_proc_release(struct inode *inode, struct file *file)
projects / firefly-linux-kernel-4.4.55.git / blobdiff