#define SEQ_MULTIPLIER (IPCMNI)
-void sem_init (void);
-void msg_init (void);
-void shm_init (void);
+void sem_init(void);
+void msg_init(void);
+void shm_init(void);
struct ipc_namespace;
* . routine to call for an extra check if needed
*/
struct ipc_ops {
- int (*getnew) (struct ipc_namespace *, struct ipc_params *);
- int (*associate) (struct kern_ipc_perm *, int);
- int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *);
+ int (*getnew)(struct ipc_namespace *, struct ipc_params *);
+ int (*associate)(struct kern_ipc_perm *, int);
+ int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *);
};
struct seq_file;
#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
#define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
+#define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX)
/* must be called with ids->rwsem acquired for writing */
int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
/* for rare, potentially huge allocations.
* both function can sleep
*/
-void* ipc_alloc(int size);
-void ipc_free(void* ptr, int size);
+void *ipc_alloc(int size);
+void ipc_free(void *ptr, int size);
/*
* For allocation that need to be freed by RCU.
* getref increases the refcount, the putref call that reduces the recount
* to 0 schedules the rcu destruction. Caller must guarantee locking.
*/
-void* ipc_rcu_alloc(int size);
+void *ipc_rcu_alloc(int size);
int ipc_rcu_getref(void *ptr);
void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head));
void ipc_rcu_free(struct rcu_head *head);
struct ipc64_perm *perm, int extra_perm);
#ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
- /* On IA-64, we always use the "64-bit version" of the IPC structures. */
+/* On IA-64, we always use the "64-bit version" of the IPC structures. */
# define ipc_parse_version(cmd) IPC_64
#else
-int ipc_parse_version (int *cmd);
+int ipc_parse_version(int *cmd);
#endif
extern void free_msg(struct msg_msg *msg);
rcu_read_unlock();
}
+/*
+ * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths
+ * where the respective ipc_ids.rwsem is not being held down.
+ * Checks whether the ipc object is still around or if it's gone already, as
+ * ipc_rmid() may have already freed the ID while the ipc lock was spinning.
+ * Needs to be called with kern_ipc_perm.lock held -- exception made for one
+ * checkpoint case at sys_semtimedop() as noted in code commentary.
+ */
+static inline bool ipc_valid_object(struct kern_ipc_perm *perm)
+{
+ return !perm->deleted;
+}
+
struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
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);
void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
void (*free)(struct ipc_namespace *, struct kern_ipc_perm *));
#endif