int in_use;
unsigned short seq;
unsigned short seq_max;
- struct mutex mutex;
+ struct rw_semaphore rw_mutex;
struct idr ipcs_idr;
};
* the calls to sys_msgget(), sys_semget(), sys_shmget()
* . routine to call to create a new ipc object. Can be one of newque,
* newary, newseg
- * . routine to call to call to check permissions for a new ipc object.
+ * . routine to call to check permissions for a new ipc object.
* Can be one of security_msg_associate, security_sem_associate,
* security_shm_associate
* . routine to call for an extra check if needed
*/
struct ipc_ops {
int (*getnew) (struct ipc_namespace *, struct ipc_params *);
- int (*associate) (void *, int);
- int (*more_checks) (void *, struct ipc_params *);
+ int (*associate) (struct kern_ipc_perm *, int);
+ int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *);
};
struct seq_file;
#define IPC_MSG_IDS 1
#define IPC_SHM_IDS 2
-/* must be called with ids->mutex acquired.*/
+#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
+
+/* must be called with ids->rw_mutex acquired for writing */
int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
+
+/* must be called with ids->rw_mutex acquired for reading */
int ipc_get_maxid(struct ipc_ids *);
/* must be called with both locks acquired. */
void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
-int ipcperms (struct kern_ipc_perm *ipcp, short flg);
+/* must be called with ipcp locked */
+int ipcperms(struct kern_ipc_perm *ipcp, short flg);
/* for rare, potentially huge allocations.
* both function can sleep
void ipc_rcu_getref(void *ptr);
void ipc_rcu_putref(void *ptr);
+/*
+ * ipc_lock_down: called with rw_mutex held
+ * ipc_lock: called without that lock held
+ */
+struct kern_ipc_perm *ipc_lock_down(struct ipc_ids *, int);
struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
-int ipc_buildid(struct ipc_ids* ids, int id, int seq);
void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
extern int ipcget_public(struct ipc_namespace *, struct ipc_ids *,
struct ipc_ops *, struct ipc_params *);
-static inline int ipc_checkid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp,
- int uid)
+static inline int ipc_buildid(int id, int seq)
+{
+ return SEQ_MULTIPLIER * seq + id;
+}
+
+/*
+ * Must be called with ipcp locked
+ */
+static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid)
{
if (uid / SEQ_MULTIPLIER != ipcp->seq)
return 1;
rcu_read_unlock();
}
+static inline struct kern_ipc_perm *ipc_lock_check_down(struct ipc_ids *ids,
+ int id)
+{
+ struct kern_ipc_perm *out;
+
+ out = ipc_lock_down(ids, id);
+ if (IS_ERR(out))
+ return out;
+
+ if (ipc_checkid(out, id)) {
+ ipc_unlock(out);
+ return ERR_PTR(-EIDRM);
+ }
+
+ return out;
+}
+
static inline struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids,
int id)
{
if (IS_ERR(out))
return out;
- if (ipc_checkid(ids, out, id)) {
+ 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().
+ */
static inline int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
struct ipc_ops *ops, struct ipc_params *params)
{