Fixed MTP to work with TWRP

include/linux/ipc_namespace.h

@@ -0,0 +1,179 @@
+#ifndef __IPC_NAMESPACE_H__
+#define __IPC_NAMESPACE_H__
+
+#include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/rwsem.h>
+#include <linux/notifier.h>
+#include <linux/nsproxy.h>
+
+/*
+ * ipc namespace events
+ */
+#define IPCNS_MEMCHANGED   0x00000001   /* Notify lowmem size changed */
+#define IPCNS_CREATED  0x00000002   /* Notify new ipc namespace created */
+#define IPCNS_REMOVED  0x00000003   /* Notify ipc namespace removed */
+
+#define IPCNS_CALLBACK_PRI 0
+
+struct user_namespace;
+
+struct ipc_ids {
+	int in_use;
+	unsigned short seq;
+	struct rw_semaphore rwsem;
+	struct idr ipcs_idr;
+	int next_id;
+};
+
+struct ipc_namespace {
+	atomic_t	count;
+	struct ipc_ids	ids[3];
+
+	int		sem_ctls[4];
+	int		used_sems;
+
+	unsigned int	msg_ctlmax;
+	unsigned int	msg_ctlmnb;
+	unsigned int	msg_ctlmni;
+	atomic_t	msg_bytes;
+	atomic_t	msg_hdrs;
+	int		auto_msgmni;
+
+	size_t		shm_ctlmax;
+	size_t		shm_ctlall;
+	unsigned long	shm_tot;
+	int		shm_ctlmni;
+	/*
+	 * Defines whether IPC_RMID is forced for _all_ shm segments regardless
+	 * of shmctl()
+	 */
+	int		shm_rmid_forced;
+
+	struct notifier_block ipcns_nb;
+
+	/* The kern_mount of the mqueuefs sb.  We take a ref on it */
+	struct vfsmount	*mq_mnt;
+
+	/* # queues in this ns, protected by mq_lock */
+	unsigned int    mq_queues_count;
+
+	/* next fields are set through sysctl */
+	unsigned int    mq_queues_max;   /* initialized to DFLT_QUEUESMAX */
+	unsigned int    mq_msg_max;      /* initialized to DFLT_MSGMAX */
+	unsigned int    mq_msgsize_max;  /* initialized to DFLT_MSGSIZEMAX */
+	unsigned int    mq_msg_default;
+	unsigned int    mq_msgsize_default;
+
+	/* user_ns which owns the ipc ns */
+	struct user_namespace *user_ns;
+
+	unsigned int	proc_inum;
+};
+
+extern struct ipc_namespace init_ipc_ns;
+extern atomic_t nr_ipc_ns;
+
+extern spinlock_t mq_lock;
+
+#ifdef CONFIG_SYSVIPC
+extern int register_ipcns_notifier(struct ipc_namespace *);
+extern int cond_register_ipcns_notifier(struct ipc_namespace *);
+extern void unregister_ipcns_notifier(struct ipc_namespace *);
+extern int ipcns_notify(unsigned long);
+extern void shm_destroy_orphaned(struct ipc_namespace *ns);
+#else /* CONFIG_SYSVIPC */
+static inline int register_ipcns_notifier(struct ipc_namespace *ns)
+{ return 0; }
+static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
+{ return 0; }
+static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
+static inline int ipcns_notify(unsigned long l) { return 0; }
+static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
+#endif /* CONFIG_SYSVIPC */
+
+#ifdef CONFIG_POSIX_MQUEUE
+extern int mq_init_ns(struct ipc_namespace *ns);
+/*
+ * POSIX Message Queue default values:
+ *
+ * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
+ * DFLT_*MAX: Default values for the maximum unprivileged limits
+ * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
+ *   an attribute to the open call and the queue must be created
+ * HARD_*: Highest value the maximums can be set to.  These are enforced
+ *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
+ *   suitably high)
+ *
+ * POSIX Requirements:
+ *   Per app minimum openable message queues - 8.  This does not map well
+ *     to the fact that we limit the number of queues on a per namespace
+ *     basis instead of a per app basis.  So, make the default high enough
+ *     that no given app should have a hard time opening 8 queues.
+ *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
+ *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
+ *     we have run into a situation where running applications in the wild
+ *     require this to be at least 5MB, and preferably 10MB, so I set the
+ *     value to 16MB in hopes that this user is the worst of the bunch and
+ *     the new maximum will handle anyone else.  I may have to revisit this
+ *     in the future.
+ */
+#define DFLT_QUEUESMAX		      256
+#define MIN_MSGMAX			1
+#define DFLT_MSG		       10U
+#define DFLT_MSGMAX		       10
+#define HARD_MSGMAX		    65536
+#define MIN_MSGSIZEMAX		      128
+#define DFLT_MSGSIZE		     8192U
+#define DFLT_MSGSIZEMAX		     8192
+#define HARD_MSGSIZEMAX	    (16*1024*1024)
+#else
+static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
+#endif
+
+#if defined(CONFIG_IPC_NS)
+extern struct ipc_namespace *copy_ipcs(unsigned long flags,
+	struct user_namespace *user_ns, struct ipc_namespace *ns);
+
+static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
+{
+	if (ns)
+		atomic_inc(&ns->count);
+	return ns;
+}
+
+extern void put_ipc_ns(struct ipc_namespace *ns);
+#else
+static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
+	struct user_namespace *user_ns, struct ipc_namespace *ns)
+{
+	if (flags & CLONE_NEWIPC)
+		return ERR_PTR(-EINVAL);
+
+	return ns;
+}
+
+static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
+{
+	return ns;
+}
+
+static inline void put_ipc_ns(struct ipc_namespace *ns)
+{
+}
+#endif
+
+#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
+
+struct ctl_table_header;
+extern struct ctl_table_header *mq_register_sysctl_table(void);
+
+#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
+
+static inline struct ctl_table_header *mq_register_sysctl_table(void)
+{
+	return NULL;
+}
+
+#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
+#endif