--- /dev/null
+/*
+ * linux/ipc/util.h
+ * Copyright (C) 1999 Christoph Rohland
+ *
+ * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com>
+ * namespaces support. 2006 OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
+ */
+
+#ifndef _IPC_UTIL_H
+#define _IPC_UTIL_H
+
+#include <linux/unistd.h>
+#include <linux/err.h>
+
+#define SEQ_MULTIPLIER (IPCMNI)
+
+void sem_init(void);
+void msg_init(void);
+void shm_init(void);
+
+struct ipc_namespace;
+
+#ifdef CONFIG_POSIX_MQUEUE
+extern void mq_clear_sbinfo(struct ipc_namespace *ns);
+extern void mq_put_mnt(struct ipc_namespace *ns);
+#else
+static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { }
+static inline void mq_put_mnt(struct ipc_namespace *ns) { }
+#endif
+
+#ifdef CONFIG_SYSVIPC
+void sem_init_ns(struct ipc_namespace *ns);
+void msg_init_ns(struct ipc_namespace *ns);
+void shm_init_ns(struct ipc_namespace *ns);
+
+void sem_exit_ns(struct ipc_namespace *ns);
+void msg_exit_ns(struct ipc_namespace *ns);
+void shm_exit_ns(struct ipc_namespace *ns);
+#else
+static inline void sem_init_ns(struct ipc_namespace *ns) { }
+static inline void msg_init_ns(struct ipc_namespace *ns) { }
+static inline void shm_init_ns(struct ipc_namespace *ns) { }
+
+static inline void sem_exit_ns(struct ipc_namespace *ns) { }
+static inline void msg_exit_ns(struct ipc_namespace *ns) { }
+static inline void shm_exit_ns(struct ipc_namespace *ns) { }
+#endif
+
+struct ipc_rcu {
+ struct rcu_head rcu;
+ atomic_t refcount;
+} ____cacheline_aligned_in_smp;
+
+#define ipc_rcu_to_struct(p) ((void *)(p+1))
+
+/*
+ * Structure that holds the parameters needed by the ipc operations
+ * (see after)
+ */
+struct ipc_params {
+ key_t key;
+ int flg;
+ union {
+ size_t size; /* for shared memories */
+ int nsems; /* for semaphores */
+ } u; /* holds the getnew() specific param */
+};
+
+/*
+ * Structure that holds some ipc operations. This structure is used to unify
+ * 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 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)(struct kern_ipc_perm *, int);
+ int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *);
+};
+
+struct seq_file;
+struct ipc_ids;
+
+void ipc_init_ids(struct ipc_ids *);
+#ifdef CONFIG_PROC_FS
+void __init ipc_init_proc_interface(const char *path, const char *header,
+ int ids, int (*show)(struct seq_file *, void *));
+#else
+#define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
+#endif
+
+#define IPC_SEM_IDS 0
+#define IPC_MSG_IDS 1
+#define IPC_SHM_IDS 2
+
+#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);
+
+/* must be called with ids->rwsem 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 *);
+
+/* must be called with ipcp locked */
+int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
+
+/* for rare, potentially huge allocations.
+ * both function can sleep
+ */
+void *ipc_alloc(int size);
+void ipc_free(void *ptr, int size);
+
+/*
+ * For allocation that need to be freed by RCU.
+ * Objects are reference counted, they start with reference count 1.
+ * 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);
+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 kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
+struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id);
+
+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);
+int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
+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);
+
+#ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+/* 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);
+#endif
+
+extern void free_msg(struct msg_msg *msg);
+extern struct msg_msg *load_msg(const void __user *src, size_t len);
+extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst);
+extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len);
+
+extern void recompute_msgmni(struct ipc_namespace *);
+
+static inline int ipc_buildid(int id, int seq)
+{
+ return SEQ_MULTIPLIER * seq + id;
+}
+
+static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid)
+{
+ return uid / SEQ_MULTIPLIER != ipcp->seq;
+}
+
+static inline void ipc_lock_object(struct kern_ipc_perm *perm)
+{
+ spin_lock(&perm->lock);
+}
+
+static inline void ipc_unlock_object(struct kern_ipc_perm *perm)
+{
+ spin_unlock(&perm->lock);
+}
+
+static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm)
+{
+ assert_spin_locked(&perm->lock);
+}
+
+static inline void ipc_unlock(struct kern_ipc_perm *perm)
+{
+ ipc_unlock_object(perm);
+ 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,
+ 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
Code Review / kvmfornfv.git / blobdiff