Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

10 files changed, 6045 insertions, 0 deletions

diff --git a/ipc/Makefile b/ipc/Makefile
new file mode 100644
index 0000000..0a6d626
--- /dev/null
+++ b/ipc/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile for the linux ipc.
+#
+
+obj-$(CONFIG_SYSVIPC_COMPAT) += compat.o
+obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o
+obj_mq-$(CONFIG_COMPAT) += compat_mq.o
+obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o $(obj_mq-y)
+
diff --git a/ipc/compat.c b/ipc/compat.c
new file mode 100644
index 0000000..70e4e4e
--- /dev/null
+++ b/ipc/compat.c
@@ -0,0 +1,687 @@
+/*
+ * 32 bit compatibility code for System V IPC
+ *
+ * Copyright (C) 1997,1998	Jakub Jelinek (jj@sunsite.mff.cuni.cz)
+ * Copyright (C) 1997		David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 1999		Arun Sharma <arun.sharma@intel.com>
+ * Copyright (C) 2000		VA Linux Co
+ * Copyright (C) 2000		Don Dugger <n0ano@valinux.com>
+ * Copyright (C) 2000           Hewlett-Packard Co.
+ * Copyright (C) 2000           David Mosberger-Tang <davidm@hpl.hp.com>
+ * Copyright (C) 2000           Gerhard Tonn (ton@de.ibm.com)
+ * Copyright (C) 2000-2002      Andi Kleen, SuSE Labs (x86-64 port)
+ * Copyright (C) 2000		Silicon Graphics, Inc.
+ * Copyright (C) 2001		IBM
+ * Copyright (C) 2004		IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Copyright (C) 2004		Arnd Bergmann (arnd@arndb.de)
+ *
+ * This code is collected from the versions for sparc64, mips64, s390x, ia64,
+ * ppc64 and x86_64, all of which are based on the original sparc64 version
+ * by Jakub Jelinek.
+ *
+ */
+#include <linux/compat.h>
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/highuid.h>
+#include <linux/init.h>
+#include <linux/msg.h>
+#include <linux/shm.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+
+#include <asm/semaphore.h>
+#include <asm/uaccess.h>
+
+#include "util.h"
+
+struct compat_msgbuf {
+	compat_long_t mtype;
+	char mtext[1];
+};
+
+struct compat_ipc_perm {
+	key_t key;
+	compat_uid_t uid;
+	compat_gid_t gid;
+	compat_uid_t cuid;
+	compat_gid_t cgid;
+	compat_mode_t mode;
+	unsigned short seq;
+};
+
+struct compat_semid_ds {
+	struct compat_ipc_perm sem_perm;
+	compat_time_t sem_otime;
+	compat_time_t sem_ctime;
+	compat_uptr_t sem_base;
+	compat_uptr_t sem_pending;
+	compat_uptr_t sem_pending_last;
+	compat_uptr_t undo;
+	unsigned short sem_nsems;
+};
+
+struct compat_msqid_ds {
+	struct compat_ipc_perm msg_perm;
+	compat_uptr_t msg_first;
+	compat_uptr_t msg_last;
+	compat_time_t msg_stime;
+	compat_time_t msg_rtime;
+	compat_time_t msg_ctime;
+	compat_ulong_t msg_lcbytes;
+	compat_ulong_t msg_lqbytes;
+	unsigned short msg_cbytes;
+	unsigned short msg_qnum;
+	unsigned short msg_qbytes;
+	compat_ipc_pid_t msg_lspid;
+	compat_ipc_pid_t msg_lrpid;
+};
+
+struct compat_shmid_ds {
+	struct compat_ipc_perm shm_perm;
+	int shm_segsz;
+	compat_time_t shm_atime;
+	compat_time_t shm_dtime;
+	compat_time_t shm_ctime;
+	compat_ipc_pid_t shm_cpid;
+	compat_ipc_pid_t shm_lpid;
+	unsigned short shm_nattch;
+	unsigned short shm_unused;
+	compat_uptr_t shm_unused2;
+	compat_uptr_t shm_unused3;
+};
+
+struct compat_ipc_kludge {
+	compat_uptr_t msgp;
+	compat_long_t msgtyp;
+};
+
+struct compat_shminfo64 {
+	compat_ulong_t shmmax;
+	compat_ulong_t shmmin;
+	compat_ulong_t shmmni;
+	compat_ulong_t shmseg;
+	compat_ulong_t shmall;
+	compat_ulong_t __unused1;
+	compat_ulong_t __unused2;
+	compat_ulong_t __unused3;
+	compat_ulong_t __unused4;
+};
+
+struct compat_shm_info {
+	compat_int_t used_ids;
+	compat_ulong_t shm_tot, shm_rss, shm_swp;
+	compat_ulong_t swap_attempts, swap_successes;
+};
+
+extern int sem_ctls[];
+#define sc_semopm	(sem_ctls[2])
+#define MAXBUF (64*1024)
+
+static inline int compat_ipc_parse_version(int *cmd)
+{
+	int version = *cmd & IPC_64;
+
+	/* this is tricky: architectures that have support for the old
+	 * ipc structures in 64 bit binaries need to have IPC_64 set
+	 * in cmd, the others need to have it cleared */
+#ifndef ipc_parse_version
+	*cmd |= IPC_64;
+#else
+	*cmd &= ~IPC_64;
+#endif
+	return version;
+}
+
+static inline int __get_compat_ipc64_perm(struct ipc64_perm *p64,
+					  struct compat_ipc64_perm __user *up64)
+{
+	int err;
+
+	err  = __get_user(p64->uid, &up64->uid);
+	err |= __get_user(p64->gid, &up64->gid);
+	err |= __get_user(p64->mode, &up64->mode);
+	return err;
+}
+
+static inline int __get_compat_ipc_perm(struct ipc64_perm *p,
+					struct compat_ipc_perm __user *up)
+{
+	int err;
+
+	err  = __get_user(p->uid, &up->uid);
+	err |= __get_user(p->gid, &up->gid);
+	err |= __get_user(p->mode, &up->mode);
+	return err;
+}
+
+static inline int __put_compat_ipc64_perm(struct ipc64_perm *p64,
+					  struct compat_ipc64_perm __user *up64)
+{
+	int err;
+
+	err  = __put_user(p64->key, &up64->key);
+	err |= __put_user(p64->uid, &up64->uid);
+	err |= __put_user(p64->gid, &up64->gid);
+	err |= __put_user(p64->cuid, &up64->cuid);
+	err |= __put_user(p64->cgid, &up64->cgid);
+	err |= __put_user(p64->mode, &up64->mode);
+	err |= __put_user(p64->seq, &up64->seq);
+	return err;
+}
+
+static inline int __put_compat_ipc_perm(struct ipc64_perm *p,
+					struct compat_ipc_perm __user *up)
+{
+	int err;
+	compat_uid_t u;
+	compat_gid_t g;
+
+	err  = __put_user(p->key, &up->key);
+	SET_UID(u, p->uid);
+	err |= __put_user(u, &up->uid);
+	SET_GID(g, p->gid);
+	err |= __put_user(g, &up->gid);
+	SET_UID(u, p->cuid);
+	err |= __put_user(u, &up->cuid);
+	SET_GID(g, p->cgid);
+	err |= __put_user(g, &up->cgid);
+	err |= __put_user(p->mode, &up->mode);
+	err |= __put_user(p->seq, &up->seq);
+	return err;
+}
+
+static inline int get_compat_semid64_ds(struct semid64_ds *s64,
+					struct compat_semid64_ds __user *up64)
+{
+	if (!access_ok (VERIFY_READ, up64, sizeof(*up64)))
+		return -EFAULT;
+	return __get_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
+}
+
+static inline int get_compat_semid_ds(struct semid64_ds *s,
+				      struct compat_semid_ds __user *up)
+{
+	if (!access_ok (VERIFY_READ, up, sizeof(*up)))
+		return -EFAULT;
+	return __get_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
+}
+
+static inline int put_compat_semid64_ds(struct semid64_ds *s64,
+					struct compat_semid64_ds __user *up64)
+{
+	int err;
+
+	if (!access_ok (VERIFY_WRITE, up64, sizeof(*up64)))
+		return -EFAULT;
+	err  = __put_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
+	err |= __put_user(s64->sem_otime, &up64->sem_otime);
+	err |= __put_user(s64->sem_ctime, &up64->sem_ctime);
+	err |= __put_user(s64->sem_nsems, &up64->sem_nsems);
+	return err;
+}
+
+static inline int put_compat_semid_ds(struct semid64_ds *s,
+				      struct compat_semid_ds __user *up)
+{
+	int err;
+
+	if (!access_ok (VERIFY_WRITE, up, sizeof(*up)))
+		err = -EFAULT;
+	err  = __put_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
+	err |= __put_user(s->sem_otime, &up->sem_otime);
+	err |= __put_user(s->sem_ctime, &up->sem_ctime);
+	err |= __put_user(s->sem_nsems, &up->sem_nsems);
+	return err;
+}
+
+long compat_sys_semctl(int first, int second, int third, void __user *uptr)
+{
+	union semun fourth;
+	u32 pad;
+	int err, err2;
+	struct semid64_ds s64;
+	struct semid64_ds __user *up64;
+	int version = compat_ipc_parse_version(&third);
+
+	if (!uptr)
+		return -EINVAL;
+	if (get_user(pad, (u32 __user *) uptr))
+		return -EFAULT;
+	if ((third & (~IPC_64)) == SETVAL)
+		fourth.val = (int) pad;
+	else
+		fourth.__pad = compat_ptr(pad);
+	switch (third & (~IPC_64)) {
+	case IPC_INFO:
+	case IPC_RMID:
+	case SEM_INFO:
+	case GETVAL:
+	case GETPID:
+	case GETNCNT:
+	case GETZCNT:
+	case GETALL:
+	case SETVAL:
+	case SETALL:
+		err = sys_semctl(first, second, third, fourth);
+		break;
+
+	case IPC_STAT:
+	case SEM_STAT:
+		up64 = compat_alloc_user_space(sizeof(s64));
+		fourth.__pad = up64;
+		err = sys_semctl(first, second, third, fourth);
+		if (err < 0)
+			break;
+		if (copy_from_user(&s64, up64, sizeof(s64)))
+			err2 = -EFAULT;
+		else if (version == IPC_64)
+			err2 = put_compat_semid64_ds(&s64, compat_ptr(pad));
+		else
+			err2 = put_compat_semid_ds(&s64, compat_ptr(pad));
+		if (err2)
+			err = -EFAULT;
+		break;
+
+	case IPC_SET:
+		if (version == IPC_64) {
+			err = get_compat_semid64_ds(&s64, compat_ptr(pad));
+		} else {
+			err = get_compat_semid_ds(&s64, compat_ptr(pad));
+		}
+		up64 = compat_alloc_user_space(sizeof(s64));
+		if (copy_to_user(up64, &s64, sizeof(s64)))
+			err = -EFAULT;
+		if (err)
+			break;
+
+		fourth.__pad = up64;
+		err = sys_semctl(first, second, third, fourth);
+		break;
+
+	default:
+		err = -EINVAL;
+		break;
+	}
+	return err;
+}
+
+long compat_sys_msgsnd(int first, int second, int third, void __user *uptr)
+{
+	struct msgbuf __user *p;
+	struct compat_msgbuf __user *up = uptr;
+	long type;
+
+	if (first < 0)
+		return -EINVAL;
+	if (second < 0 || (second >= MAXBUF - sizeof(struct msgbuf)))
+		return -EINVAL;
+
+	p = compat_alloc_user_space(second + sizeof(struct msgbuf));
+	if (get_user(type, &up->mtype) ||
+	    put_user(type, &p->mtype) ||
+	    copy_in_user(p->mtext, up->mtext, second))
+		return -EFAULT;
+
+	return sys_msgsnd(first, p, second, third);
+}
+
+long compat_sys_msgrcv(int first, int second, int msgtyp, int third,
+			   int version, void __user *uptr)
+{
+	struct msgbuf __user *p;
+	struct compat_msgbuf __user *up;
+	long type;
+	int err;
+
+	if (first < 0)
+		return -EINVAL;
+	if (second < 0 || (second >= MAXBUF - sizeof(struct msgbuf)))
+		return -EINVAL;
+
+	if (!version) {
+		struct compat_ipc_kludge ipck;
+		err = -EINVAL;
+		if (!uptr)
+			goto out;
+		err = -EFAULT;
+		if (copy_from_user (&ipck, uptr, sizeof(ipck)))
+			goto out;
+		uptr = compat_ptr(ipck.msgp);
+		msgtyp = ipck.msgtyp;
+	}
+	p = compat_alloc_user_space(second + sizeof(struct msgbuf));
+	err = sys_msgrcv(first, p, second, msgtyp, third);
+	if (err < 0)
+		goto out;
+	up = uptr;
+	if (get_user(type, &p->mtype) ||
+	    put_user(type, &up->mtype) ||
+	    copy_in_user(up->mtext, p->mtext, err))
+		err = -EFAULT;
+out:
+	return err;
+}
+
+static inline int get_compat_msqid64(struct msqid64_ds *m64,
+				     struct compat_msqid64_ds __user *up64)
+{
+	int err;
+
+	if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
+		return -EFAULT;
+	err  = __get_compat_ipc64_perm(&m64->msg_perm, &up64->msg_perm);
+	err |= __get_user(m64->msg_qbytes, &up64->msg_qbytes);
+	return err;
+}
+
+static inline int get_compat_msqid(struct msqid64_ds *m,
+				   struct compat_msqid_ds __user *up)
+{
+	int err;
+
+	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
+		return -EFAULT;
+	err  = __get_compat_ipc_perm(&m->msg_perm, &up->msg_perm);
+	err |= __get_user(m->msg_qbytes, &up->msg_qbytes);
+	return err;
+}
+
+static inline int put_compat_msqid64_ds(struct msqid64_ds *m64,
+				 struct compat_msqid64_ds __user *up64)
+{
+	int err;
+
+	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
+		return -EFAULT;
+	err  = __put_compat_ipc64_perm(&m64->msg_perm, &up64->msg_perm);
+	err |= __put_user(m64->msg_stime, &up64->msg_stime);
+	err |= __put_user(m64->msg_rtime, &up64->msg_rtime);
+	err |= __put_user(m64->msg_ctime, &up64->msg_ctime);
+	err |= __put_user(m64->msg_cbytes, &up64->msg_cbytes);
+	err |= __put_user(m64->msg_qnum, &up64->msg_qnum);
+	err |= __put_user(m64->msg_qbytes, &up64->msg_qbytes);
+	err |= __put_user(m64->msg_lspid, &up64->msg_lspid);
+	err |= __put_user(m64->msg_lrpid, &up64->msg_lrpid);
+	return err;
+}
+
+static inline int put_compat_msqid_ds(struct msqid64_ds *m,
+				      struct compat_msqid_ds __user *up)
+{
+	int err;
+
+	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
+		return -EFAULT;
+	err  = __put_compat_ipc_perm(&m->msg_perm, &up->msg_perm);
+	err |= __put_user(m->msg_stime, &up->msg_stime);
+	err |= __put_user(m->msg_rtime, &up->msg_rtime);
+	err |= __put_user(m->msg_ctime, &up->msg_ctime);
+	err |= __put_user(m->msg_cbytes, &up->msg_cbytes);
+	err |= __put_user(m->msg_qnum, &up->msg_qnum);
+	err |= __put_user(m->msg_qbytes, &up->msg_qbytes);
+	err |= __put_user(m->msg_lspid, &up->msg_lspid);
+	err |= __put_user(m->msg_lrpid, &up->msg_lrpid);
+	return err;
+}
+
+long compat_sys_msgctl(int first, int second, void __user *uptr)
+{
+	int err, err2;
+	struct msqid64_ds m64;
+	int version = compat_ipc_parse_version(&second);
+	void __user *p;
+
+	switch (second & (~IPC_64)) {
+	case IPC_INFO:
+	case IPC_RMID:
+	case MSG_INFO:
+		err = sys_msgctl(first, second, uptr);
+		break;
+
+	case IPC_SET:
+		if (version == IPC_64) {
+			err = get_compat_msqid64(&m64, uptr);
+		} else {
+			err = get_compat_msqid(&m64, uptr);
+		}
+		if (err)
+			break;
+		p = compat_alloc_user_space(sizeof(m64));
+		if (copy_to_user(p, &m64, sizeof(m64)))
+			err = -EFAULT;
+		else
+			err = sys_msgctl(first, second, p);
+		break;
+
+	case IPC_STAT:
+	case MSG_STAT:
+		p = compat_alloc_user_space(sizeof(m64));
+		err = sys_msgctl(first, second, p);
+		if (err < 0)
+			break;
+		if (copy_from_user(&m64, p, sizeof(m64)))
+			err2 = -EFAULT;
+		else if (version == IPC_64)
+			err2 = put_compat_msqid64_ds(&m64, uptr);
+		else
+			err2 = put_compat_msqid_ds(&m64, uptr);
+		if (err2)
+			err = -EFAULT;
+		break;
+
+	default:
+		err = -EINVAL;
+		break;
+	}
+	return err;
+}
+
+long compat_sys_shmat(int first, int second, compat_uptr_t third, int version,
+			void __user *uptr)
+{
+	int err;
+	unsigned long raddr;
+	compat_ulong_t __user *uaddr;
+
+	if (version == 1)
+		return -EINVAL;
+	err = do_shmat(first, uptr, second, &raddr);
+	if (err < 0)
+		return err;
+	uaddr = compat_ptr(third);
+	return put_user(raddr, uaddr);
+}
+
+static inline int get_compat_shmid64_ds(struct shmid64_ds *s64,
+					struct compat_shmid64_ds __user *up64)
+{
+	if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
+		return -EFAULT;
+	return __get_compat_ipc64_perm(&s64->shm_perm, &up64->shm_perm);
+}
+
+static inline int get_compat_shmid_ds(struct shmid64_ds *s,
+				      struct compat_shmid_ds __user *up)
+{
+	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
+		return -EFAULT;
+	return __get_compat_ipc_perm(&s->shm_perm, &up->shm_perm);
+}
+
+static inline int put_compat_shmid64_ds(struct shmid64_ds *s64,
+					struct compat_shmid64_ds __user *up64)
+{
+	int err;
+
+	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
+		return -EFAULT;
+	err  = __put_compat_ipc64_perm(&s64->shm_perm, &up64->shm_perm);
+	err |= __put_user(s64->shm_atime, &up64->shm_atime);
+	err |= __put_user(s64->shm_dtime, &up64->shm_dtime);
+	err |= __put_user(s64->shm_ctime, &up64->shm_ctime);
+	err |= __put_user(s64->shm_segsz, &up64->shm_segsz);
+	err |= __put_user(s64->shm_nattch, &up64->shm_nattch);
+	err |= __put_user(s64->shm_cpid, &up64->shm_cpid);
+	err |= __put_user(s64->shm_lpid, &up64->shm_lpid);
+	return err;
+}
+
+static inline int put_compat_shmid_ds(struct shmid64_ds *s,
+				      struct compat_shmid_ds __user *up)
+{
+	int err;
+
+	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
+		return -EFAULT;
+	err  = __put_compat_ipc_perm(&s->shm_perm, &up->shm_perm);
+	err |= __put_user(s->shm_atime, &up->shm_atime);
+	err |= __put_user(s->shm_dtime, &up->shm_dtime);
+	err |= __put_user(s->shm_ctime, &up->shm_ctime);
+	err |= __put_user(s->shm_segsz, &up->shm_segsz);
+	err |= __put_user(s->shm_nattch, &up->shm_nattch);
+	err |= __put_user(s->shm_cpid, &up->shm_cpid);
+	err |= __put_user(s->shm_lpid, &up->shm_lpid);
+	return err;
+}
+
+static inline int put_compat_shminfo64(struct shminfo64 *smi,
+				       struct compat_shminfo64 __user *up64)
+{
+	int err;
+
+	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
+		return -EFAULT;
+	err  = __put_user(smi->shmmax, &up64->shmmax);
+	err |= __put_user(smi->shmmin, &up64->shmmin);
+	err |= __put_user(smi->shmmni, &up64->shmmni);
+	err |= __put_user(smi->shmseg, &up64->shmseg);
+	err |= __put_user(smi->shmall, &up64->shmall);
+	return err;
+}
+
+static inline int put_compat_shminfo(struct shminfo64 *smi,
+				     struct shminfo __user *up)
+{
+	int err;
+
+	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
+		return -EFAULT;
+	err  = __put_user(smi->shmmax, &up->shmmax);
+	err |= __put_user(smi->shmmin, &up->shmmin);
+	err |= __put_user(smi->shmmni, &up->shmmni);
+	err |= __put_user(smi->shmseg, &up->shmseg);
+	err |= __put_user(smi->shmall, &up->shmall);
+}
+
+static inline int put_compat_shm_info(struct shm_info __user *ip,
+				      struct compat_shm_info __user *uip)
+{
+	int err;
+	struct shm_info si;
+
+	if (!access_ok(VERIFY_WRITE, uip, sizeof(*uip)) ||
+	    copy_from_user(&si, ip, sizeof(si)))
+		return -EFAULT;
+	err  = __put_user(si.used_ids, &uip->used_ids);
+	err |= __put_user(si.shm_tot, &uip->shm_tot);
+	err |= __put_user(si.shm_rss, &uip->shm_rss);
+	err |= __put_user(si.shm_swp, &uip->shm_swp);
+	err |= __put_user(si.swap_attempts, &uip->swap_attempts);
+	err |= __put_user(si.swap_successes, &uip->swap_successes);
+	return err;
+}
+
+long compat_sys_shmctl(int first, int second, void __user *uptr)
+{
+	void __user *p;
+	struct shmid64_ds s64;
+	struct shminfo64 smi;
+	int err, err2;
+	int version = compat_ipc_parse_version(&second);
+
+	switch (second & (~IPC_64)) {
+	case IPC_RMID:
+	case SHM_LOCK:
+	case SHM_UNLOCK:
+		err = sys_shmctl(first, second, uptr);
+		break;
+
+	case IPC_INFO:
+		p = compat_alloc_user_space(sizeof(smi));
+		err = sys_shmctl(first, second, p);
+		if (err < 0)
+			break;
+		if (copy_from_user(&smi, p, sizeof(smi)))
+			err2 = -EFAULT;
+		else if (version == IPC_64)
+			err2 = put_compat_shminfo64(&smi, uptr);
+		else
+			err2 = put_compat_shminfo(&smi, uptr);
+		if (err2)
+			err = -EFAULT;
+		break;
+
+
+	case IPC_SET:
+		if (version == IPC_64) {
+			err = get_compat_shmid64_ds(&s64, uptr);
+		} else {
+			err = get_compat_shmid_ds(&s64, uptr);
+		}
+		if (err)
+			break;
+		p = compat_alloc_user_space(sizeof(s64));
+		if (copy_to_user(p, &s64, sizeof(s64)))
+			err = -EFAULT;
+		else
+			err = sys_shmctl(first, second, p);
+		break;
+
+	case IPC_STAT:
+	case SHM_STAT:
+		p = compat_alloc_user_space(sizeof(s64));
+		err = sys_shmctl(first, second, p);
+		if (err < 0)
+			break;
+		if (copy_from_user(&s64, p, sizeof(s64)))
+			err2 = -EFAULT;
+		else if (version == IPC_64)
+			err2 = put_compat_shmid64_ds(&s64, uptr);
+		else
+			err2 = put_compat_shmid_ds(&s64, uptr);
+		if (err2)
+			err = -EFAULT;
+		break;
+
+	case SHM_INFO:
+		p = compat_alloc_user_space(sizeof(struct shm_info));
+		err = sys_shmctl(first, second, p);
+		if (err < 0)
+			break;
+		err2 = put_compat_shm_info(p, uptr);
+		if (err2)
+			err = -EFAULT;
+		break;
+
+	default:
+		err = -EINVAL;
+		break;
+	}
+	return err;
+}
+
+long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,
+		unsigned nsops, const struct compat_timespec __user *timeout)
+{
+	struct timespec __user *ts64 = NULL;
+	if (timeout) {
+		struct timespec ts;
+		ts64 = compat_alloc_user_space(sizeof(*ts64));
+		if (get_compat_timespec(&ts, timeout))
+			return -EFAULT;
+		if (copy_to_user(ts64, &ts, sizeof(ts)))
+			return -EFAULT;
+	}
+	return sys_semtimedop(semid, tsems, nsops, ts64);
+}
diff --git a/ipc/compat_mq.c b/ipc/compat_mq.c
new file mode 100644
index 0000000..d8d1e9f
--- /dev/null
+++ b/ipc/compat_mq.c
@@ -0,0 +1,146 @@
+/*
+ *  ipc/compat_mq.c
+ *    32 bit emulation for POSIX message queue system calls
+ *
+ *    Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author: Arnd Bergmann <arnd@arndb.de>
+ */
+
+#include <linux/compat.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/mqueue.h>
+#include <linux/syscalls.h>
+
+#include <asm/uaccess.h>
+
+struct compat_mq_attr {
+	compat_long_t mq_flags;      /* message queue flags		     */
+	compat_long_t mq_maxmsg;     /* maximum number of messages	     */
+	compat_long_t mq_msgsize;    /* maximum message size		     */
+	compat_long_t mq_curmsgs;    /* number of messages currently queued  */
+	compat_long_t __reserved[4]; /* ignored for input, zeroed for output */
+};
+
+static inline int get_compat_mq_attr(struct mq_attr *attr,
+			const struct compat_mq_attr __user *uattr)
+{
+	if (!access_ok(VERIFY_READ, uattr, sizeof *uattr))
+		return -EFAULT;
+
+	return __get_user(attr->mq_flags, &uattr->mq_flags)
+		| __get_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
+		| __get_user(attr->mq_msgsize, &uattr->mq_msgsize)
+		| __get_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
+}
+
+static inline int put_compat_mq_attr(const struct mq_attr *attr,
+			struct compat_mq_attr __user *uattr)
+{
+	if (clear_user(uattr, sizeof *uattr))
+		return -EFAULT;
+
+	return __put_user(attr->mq_flags, &uattr->mq_flags)
+		| __put_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
+		| __put_user(attr->mq_msgsize, &uattr->mq_msgsize)
+		| __put_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
+}
+
+asmlinkage long compat_sys_mq_open(const char __user *u_name,
+			int oflag, compat_mode_t mode,
+			struct compat_mq_attr __user *u_attr)
+{
+	void __user *p = NULL;
+	if (u_attr && oflag & O_CREAT) {
+		struct mq_attr attr;
+		p = compat_alloc_user_space(sizeof(attr));
+		if (get_compat_mq_attr(&attr, u_attr) ||
+		    copy_to_user(p, &attr, sizeof(attr)))
+			return -EFAULT;
+	}
+	return sys_mq_open(u_name, oflag, mode, p);
+}
+
+static int compat_prepare_timeout(struct timespec __user * *p,
+				  const struct compat_timespec __user *u)
+{
+	struct timespec ts;
+	if (!u) {
+		*p = NULL;
+		return 0;
+	}
+	*p = compat_alloc_user_space(sizeof(ts));
+	if (get_compat_timespec(&ts, u) || copy_to_user(*p, &ts, sizeof(ts)))
+		return -EFAULT;
+	return 0;
+}
+
+asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes,
+			const char __user *u_msg_ptr,
+			size_t msg_len, unsigned int msg_prio,
+			const struct compat_timespec __user *u_abs_timeout)
+{
+	struct timespec __user *u_ts;
+
+	if (compat_prepare_timeout(&u_ts, u_abs_timeout))
+		return -EFAULT;
+
+	return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len,
+			msg_prio, u_ts);
+}
+
+asmlinkage ssize_t compat_sys_mq_timedreceive(mqd_t mqdes,
+			char __user *u_msg_ptr,
+			size_t msg_len, unsigned int __user *u_msg_prio,
+			const struct compat_timespec __user *u_abs_timeout)
+{
+	struct timespec __user *u_ts;
+	if (compat_prepare_timeout(&u_ts, u_abs_timeout))
+		return -EFAULT;
+
+	return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len,
+			u_msg_prio, u_ts);
+}
+
+asmlinkage long compat_sys_mq_notify(mqd_t mqdes,
+			const struct compat_sigevent __user *u_notification)
+{
+	struct sigevent __user *p = NULL;
+	if (u_notification) {
+		struct sigevent n;
+		p = compat_alloc_user_space(sizeof(*p));
+		if (get_compat_sigevent(&n, u_notification))
+			return -EFAULT;
+		if (n.sigev_notify == SIGEV_THREAD)
+			n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
+		if (copy_to_user(p, &n, sizeof(*p)))
+			return -EFAULT;
+	}
+	return sys_mq_notify(mqdes, p);
+}
+
+asmlinkage long compat_sys_mq_getsetattr(mqd_t mqdes,
+			const struct compat_mq_attr __user *u_mqstat,
+			struct compat_mq_attr __user *u_omqstat)
+{
+	struct mq_attr mqstat;
+	struct mq_attr __user *p = compat_alloc_user_space(2 * sizeof(*p));
+	long ret;
+
+	if (u_mqstat) {
+		if (get_compat_mq_attr(&mqstat, u_mqstat) ||
+		    copy_to_user(p, &mqstat, sizeof(mqstat)))
+			return -EFAULT;
+	}
+	ret = sys_mq_getsetattr(mqdes,
+				u_mqstat ? p : NULL,
+				u_omqstat ? p + 1 : NULL);
+	if (ret)
+		return ret;
+	if (u_omqstat) {
+		if (copy_from_user(&mqstat, p + 1, sizeof(mqstat)) ||
+		    put_compat_mq_attr(&mqstat, u_omqstat))
+			return -EFAULT;
+	}
+	return 0;
+}
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
new file mode 100644
index 0000000..cb0cd3c
--- /dev/null
+++ b/ipc/mqueue.c
@@ -0,0 +1,1252 @@
+/*
+ * POSIX message queues filesystem for Linux.
+ *
+ * Copyright (C) 2003,2004  Krzysztof Benedyczak    (golbi@mat.uni.torun.pl)
+ *                          Michal Wronski          (wrona@mat.uni.torun.pl)
+ *
+ * Spinlocks:               Mohamed Abbas           (abbas.mohamed@intel.com)
+ * Lockless receive & send, fd based notify:
+ * 			    Manfred Spraul	    (manfred@colorfullife.com)
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/sysctl.h>
+#include <linux/poll.h>
+#include <linux/mqueue.h>
+#include <linux/msg.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/syscalls.h>
+#include <net/sock.h>
+#include "util.h"
+
+#define MQUEUE_MAGIC	0x19800202
+#define DIRENT_SIZE	20
+#define FILENT_SIZE	80
+
+#define SEND		0
+#define RECV		1
+
+#define STATE_NONE	0
+#define STATE_PENDING	1
+#define STATE_READY	2
+
+/* used by sysctl */
+#define FS_MQUEUE 	1
+#define CTL_QUEUESMAX 	2
+#define CTL_MSGMAX 	3
+#define CTL_MSGSIZEMAX 	4
+
+/* default values */
+#define DFLT_QUEUESMAX	256	/* max number of message queues */
+#define DFLT_MSGMAX 	10	/* max number of messages in each queue */
+#define HARD_MSGMAX 	(131072/sizeof(void*))
+#define DFLT_MSGSIZEMAX 8192	/* max message size */
+
+#define NOTIFY_COOKIE_LEN	32
+
+struct ext_wait_queue {		/* queue of sleeping tasks */
+	struct task_struct *task;
+	struct list_head list;
+	struct msg_msg *msg;	/* ptr of loaded message */
+	int state;		/* one of STATE_* values */
+};
+
+struct mqueue_inode_info {
+	spinlock_t lock;
+	struct inode vfs_inode;
+	wait_queue_head_t wait_q;
+
+	struct msg_msg **messages;
+	struct mq_attr attr;
+
+	struct sigevent notify;
+	pid_t notify_owner;
+ 	struct user_struct *user;	/* user who created, for accouting */
+	struct sock *notify_sock;
+	struct sk_buff *notify_cookie;
+
+	/* for tasks waiting for free space and messages, respectively */
+	struct ext_wait_queue e_wait_q[2];
+
+	unsigned long qsize; /* size of queue in memory (sum of all msgs) */
+};
+
+static struct inode_operations mqueue_dir_inode_operations;
+static struct file_operations mqueue_file_operations;
+static struct super_operations mqueue_super_ops;
+static void remove_notification(struct mqueue_inode_info *info);
+
+static spinlock_t mq_lock;
+static kmem_cache_t *mqueue_inode_cachep;
+static struct vfsmount *mqueue_mnt;
+
+static unsigned int queues_count;
+static unsigned int queues_max 	= DFLT_QUEUESMAX;
+static unsigned int msg_max 	= DFLT_MSGMAX;
+static unsigned int msgsize_max = DFLT_MSGSIZEMAX;
+
+static struct ctl_table_header * mq_sysctl_table;
+
+static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
+{
+	return container_of(inode, struct mqueue_inode_info, vfs_inode);
+}
+
+static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
+							struct mq_attr *attr)
+{
+	struct inode *inode;
+
+	inode = new_inode(sb);
+	if (inode) {
+		inode->i_mode = mode;
+		inode->i_uid = current->fsuid;
+		inode->i_gid = current->fsgid;
+		inode->i_blksize = PAGE_CACHE_SIZE;
+		inode->i_blocks = 0;
+		inode->i_mtime = inode->i_ctime = inode->i_atime =
+				CURRENT_TIME;
+
+		if (S_ISREG(mode)) {
+			struct mqueue_inode_info *info;
+			struct task_struct *p = current;
+			struct user_struct *u = p->user;
+			unsigned long mq_bytes, mq_msg_tblsz;
+
+			inode->i_fop = &mqueue_file_operations;
+			inode->i_size = FILENT_SIZE;
+			/* mqueue specific info */
+			info = MQUEUE_I(inode);
+			spin_lock_init(&info->lock);
+			init_waitqueue_head(&info->wait_q);
+			INIT_LIST_HEAD(&info->e_wait_q[0].list);
+			INIT_LIST_HEAD(&info->e_wait_q[1].list);
+			info->messages = NULL;
+			info->notify_owner = 0;
+			info->qsize = 0;
+			info->user = NULL;	/* set when all is ok */
+			memset(&info->attr, 0, sizeof(info->attr));
+			info->attr.mq_maxmsg = DFLT_MSGMAX;
+			info->attr.mq_msgsize = DFLT_MSGSIZEMAX;
+			if (attr) {
+				info->attr.mq_maxmsg = attr->mq_maxmsg;
+				info->attr.mq_msgsize = attr->mq_msgsize;
+			}
+			mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
+			mq_bytes = (mq_msg_tblsz +
+				(info->attr.mq_maxmsg * info->attr.mq_msgsize));
+
+			spin_lock(&mq_lock);
+			if (u->mq_bytes + mq_bytes < u->mq_bytes ||
+		 	    u->mq_bytes + mq_bytes >
+			    p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) {
+				spin_unlock(&mq_lock);
+				goto out_inode;
+			}
+			u->mq_bytes += mq_bytes;
+			spin_unlock(&mq_lock);
+
+			info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
+			if (!info->messages) {
+				spin_lock(&mq_lock);
+				u->mq_bytes -= mq_bytes;
+				spin_unlock(&mq_lock);
+				goto out_inode;
+			}
+			/* all is ok */
+			info->user = get_uid(u);
+		} else if (S_ISDIR(mode)) {
+			inode->i_nlink++;
+			/* Some things misbehave if size == 0 on a directory */
+			inode->i_size = 2 * DIRENT_SIZE;
+			inode->i_op = &mqueue_dir_inode_operations;
+			inode->i_fop = &simple_dir_operations;
+		}
+	}
+	return inode;
+out_inode:
+	make_bad_inode(inode);
+	iput(inode);
+	return NULL;
+}
+
+static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct inode *inode;
+
+	sb->s_blocksize = PAGE_CACHE_SIZE;
+	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	sb->s_magic = MQUEUE_MAGIC;
+	sb->s_op = &mqueue_super_ops;
+
+	inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL);
+	if (!inode)
+		return -ENOMEM;
+
+	sb->s_root = d_alloc_root(inode);
+	if (!sb->s_root) {
+		iput(inode);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static struct super_block *mqueue_get_sb(struct file_system_type *fs_type,
+					 int flags, const char *dev_name,
+					 void *data)
+{
+	return get_sb_single(fs_type, flags, data, mqueue_fill_super);
+}
+
+static void init_once(void *foo, kmem_cache_t * cachep, unsigned long flags)
+{
+	struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
+
+	if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
+		SLAB_CTOR_CONSTRUCTOR)
+		inode_init_once(&p->vfs_inode);
+}
+
+static struct inode *mqueue_alloc_inode(struct super_block *sb)
+{
+	struct mqueue_inode_info *ei;
+
+	ei = kmem_cache_alloc(mqueue_inode_cachep, SLAB_KERNEL);
+	if (!ei)
+		return NULL;
+	return &ei->vfs_inode;
+}
+
+static void mqueue_destroy_inode(struct inode *inode)
+{
+	kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
+}
+
+static void mqueue_delete_inode(struct inode *inode)
+{
+	struct mqueue_inode_info *info;
+	struct user_struct *user;
+	unsigned long mq_bytes;
+	int i;
+
+	if (S_ISDIR(inode->i_mode)) {
+		clear_inode(inode);
+		return;
+	}
+	info = MQUEUE_I(inode);
+	spin_lock(&info->lock);
+	for (i = 0; i < info->attr.mq_curmsgs; i++)
+		free_msg(info->messages[i]);
+	kfree(info->messages);
+	spin_unlock(&info->lock);
+
+	clear_inode(inode);
+
+	mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) +
+		   (info->attr.mq_maxmsg * info->attr.mq_msgsize));
+	user = info->user;
+	if (user) {
+		spin_lock(&mq_lock);
+		user->mq_bytes -= mq_bytes;
+		queues_count--;
+		spin_unlock(&mq_lock);
+		free_uid(user);
+	}
+}
+
+static int mqueue_create(struct inode *dir, struct dentry *dentry,
+				int mode, struct nameidata *nd)
+{
+	struct inode *inode;
+	struct mq_attr *attr = dentry->d_fsdata;
+	int error;
+
+	spin_lock(&mq_lock);
+	if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) {
+		error = -ENOSPC;
+		goto out_lock;
+	}
+	queues_count++;
+	spin_unlock(&mq_lock);
+
+	inode = mqueue_get_inode(dir->i_sb, mode, attr);
+	if (!inode) {
+		error = -ENOMEM;
+		spin_lock(&mq_lock);
+		queues_count--;
+		goto out_lock;
+	}
+
+	dir->i_size += DIRENT_SIZE;
+	dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
+
+	d_instantiate(dentry, inode);
+	dget(dentry);
+	return 0;
+out_lock:
+	spin_unlock(&mq_lock);
+	return error;
+}
+
+static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
+{
+  	struct inode *inode = dentry->d_inode;
+
+	dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
+	dir->i_size -= DIRENT_SIZE;
+  	inode->i_nlink--;
+  	dput(dentry);
+  	return 0;
+}
+
+/*
+*	This is routine for system read from queue file.
+*	To avoid mess with doing here some sort of mq_receive we allow
+*	to read only queue size & notification info (the only values
+*	that are interesting from user point of view and aren't accessible
+*	through std routines)
+*/
+static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
+				size_t count, loff_t * off)
+{
+	struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode);
+	char buffer[FILENT_SIZE];
+	size_t slen;
+	loff_t o;
+
+	if (!count)
+		return 0;
+
+	spin_lock(&info->lock);
+	snprintf(buffer, sizeof(buffer),
+			"QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
+			info->qsize,
+			info->notify_owner ? info->notify.sigev_notify : 0,
+			(info->notify_owner &&
+			 info->notify.sigev_notify == SIGEV_SIGNAL) ?
+				info->notify.sigev_signo : 0,
+			info->notify_owner);
+	spin_unlock(&info->lock);
+	buffer[sizeof(buffer)-1] = '\0';
+	slen = strlen(buffer)+1;
+
+	o = *off;
+	if (o > slen)
+		return 0;
+
+	if (o + count > slen)
+		count = slen - o;
+
+	if (copy_to_user(u_data, buffer + o, count))
+		return -EFAULT;
+
+	*off = o + count;
+	filp->f_dentry->d_inode->i_atime = filp->f_dentry->d_inode->i_ctime = CURRENT_TIME;
+	return count;
+}
+
+static int mqueue_flush_file(struct file *filp)
+{
+	struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode);
+
+	spin_lock(&info->lock);
+	if (current->tgid == info->notify_owner)
+		remove_notification(info);
+
+	spin_unlock(&info->lock);
+	return 0;
+}
+
+static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
+{
+	struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode);
+	int retval = 0;
+
+	poll_wait(filp, &info->wait_q, poll_tab);
+
+	spin_lock(&info->lock);
+	if (info->attr.mq_curmsgs)
+		retval = POLLIN | POLLRDNORM;
+
+	if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
+		retval |= POLLOUT | POLLWRNORM;
+	spin_unlock(&info->lock);
+
+	return retval;
+}
+
+/* Adds current to info->e_wait_q[sr] before element with smaller prio */
+static void wq_add(struct mqueue_inode_info *info, int sr,
+			struct ext_wait_queue *ewp)
+{
+	struct ext_wait_queue *walk;
+
+	ewp->task = current;
+
+	list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
+		if (walk->task->static_prio <= current->static_prio) {
+			list_add_tail(&ewp->list, &walk->list);
+			return;
+		}
+	}
+	list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
+}
+
+/*
+ * Puts current task to sleep. Caller must hold queue lock. After return
+ * lock isn't held.
+ * sr: SEND or RECV
+ */
+static int wq_sleep(struct mqueue_inode_info *info, int sr,
+			long timeout, struct ext_wait_queue *ewp)
+{
+	int retval;
+	signed long time;
+
+	wq_add(info, sr, ewp);
+
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		spin_unlock(&info->lock);
+		time = schedule_timeout(timeout);
+
+		while (ewp->state == STATE_PENDING)
+			cpu_relax();
+
+		if (ewp->state == STATE_READY) {
+			retval = 0;
+			goto out;
+		}
+		spin_lock(&info->lock);
+		if (ewp->state == STATE_READY) {
+			retval = 0;
+			goto out_unlock;
+		}
+		if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+		if (time == 0) {
+			retval = -ETIMEDOUT;
+			break;
+		}
+	}
+	list_del(&ewp->list);
+out_unlock:
+	spin_unlock(&info->lock);
+out:
+	return retval;
+}
+
+/*
+ * Returns waiting task that should be serviced first or NULL if none exists
+ */
+static struct ext_wait_queue *wq_get_first_waiter(
+		struct mqueue_inode_info *info, int sr)
+{
+	struct list_head *ptr;
+
+	ptr = info->e_wait_q[sr].list.prev;
+	if (ptr == &info->e_wait_q[sr].list)
+		return NULL;
+	return list_entry(ptr, struct ext_wait_queue, list);
+}
+
+/* Auxiliary functions to manipulate messages' list */
+static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
+{
+	int k;
+
+	k = info->attr.mq_curmsgs - 1;
+	while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
+		info->messages[k + 1] = info->messages[k];
+		k--;
+	}
+	info->attr.mq_curmsgs++;
+	info->qsize += ptr->m_ts;
+	info->messages[k + 1] = ptr;
+}
+
+static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
+{
+	info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
+	return info->messages[info->attr.mq_curmsgs];
+}
+
+static inline void set_cookie(struct sk_buff *skb, char code)
+{
+	((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
+}
+
+/*
+ * The next function is only to split too long sys_mq_timedsend
+ */
+static void __do_notify(struct mqueue_inode_info *info)
+{
+	/* notification
+	 * invoked when there is registered process and there isn't process
+	 * waiting synchronously for message AND state of queue changed from
+	 * empty to not empty. Here we are sure that no one is waiting
+	 * synchronously. */
+	if (info->notify_owner &&
+	    info->attr.mq_curmsgs == 1) {
+		struct siginfo sig_i;
+		switch (info->notify.sigev_notify) {
+		case SIGEV_NONE:
+			break;
+		case SIGEV_SIGNAL:
+			/* sends signal */
+
+			sig_i.si_signo = info->notify.sigev_signo;
+			sig_i.si_errno = 0;
+			sig_i.si_code = SI_MESGQ;
+			sig_i.si_value = info->notify.sigev_value;
+			sig_i.si_pid = current->tgid;
+			sig_i.si_uid = current->uid;
+
+			kill_proc_info(info->notify.sigev_signo,
+				       &sig_i, info->notify_owner);
+			break;
+		case SIGEV_THREAD:
+			set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
+			netlink_sendskb(info->notify_sock,
+					info->notify_cookie, 0);
+			break;
+		}
+		/* after notification unregisters process */
+		info->notify_owner = 0;
+	}
+	wake_up(&info->wait_q);
+}
+
+static long prepare_timeout(const struct timespec __user *u_arg)
+{
+	struct timespec ts, nowts;
+	long timeout;
+
+	if (u_arg) {
+		if (unlikely(copy_from_user(&ts, u_arg,
+					sizeof(struct timespec))))
+			return -EFAULT;
+
+		if (unlikely(ts.tv_nsec < 0 || ts.tv_sec < 0
+			|| ts.tv_nsec >= NSEC_PER_SEC))
+			return -EINVAL;
+		nowts = CURRENT_TIME;
+		/* first subtract as jiffies can't be too big */
+		ts.tv_sec -= nowts.tv_sec;
+		if (ts.tv_nsec < nowts.tv_nsec) {
+			ts.tv_nsec += NSEC_PER_SEC;
+			ts.tv_sec--;
+		}
+		ts.tv_nsec -= nowts.tv_nsec;
+		if (ts.tv_sec < 0)
+			return 0;
+
+		timeout = timespec_to_jiffies(&ts) + 1;
+	} else
+		return MAX_SCHEDULE_TIMEOUT;
+
+	return timeout;
+}
+
+static void remove_notification(struct mqueue_inode_info *info)
+{
+	if (info->notify_owner != 0 &&
+	    info->notify.sigev_notify == SIGEV_THREAD) {
+		set_cookie(info->notify_cookie, NOTIFY_REMOVED);
+		netlink_sendskb(info->notify_sock, info->notify_cookie, 0);
+	}
+	info->notify_owner = 0;
+}
+
+static int mq_attr_ok(struct mq_attr *attr)
+{
+	if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
+		return 0;
+	if (capable(CAP_SYS_RESOURCE)) {
+		if (attr->mq_maxmsg > HARD_MSGMAX)
+			return 0;
+	} else {
+		if (attr->mq_maxmsg > msg_max ||
+				attr->mq_msgsize > msgsize_max)
+			return 0;
+	}
+	/* check for overflow */
+	if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
+		return 0;
+	if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) +
+	    (attr->mq_maxmsg * sizeof (struct msg_msg *)) <
+	    (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
+		return 0;
+	return 1;
+}
+
+/*
+ * Invoked when creating a new queue via sys_mq_open
+ */
+static struct file *do_create(struct dentry *dir, struct dentry *dentry,
+			int oflag, mode_t mode, struct mq_attr __user *u_attr)
+{
+	struct file *filp;
+	struct mq_attr attr;
+	int ret;
+
+	if (u_attr != NULL) {
+		if (copy_from_user(&attr, u_attr, sizeof(attr)))
+			return ERR_PTR(-EFAULT);
+		if (!mq_attr_ok(&attr))
+			return ERR_PTR(-EINVAL);
+		/* store for use during create */
+		dentry->d_fsdata = &attr;
+	}
+
+	ret = vfs_create(dir->d_inode, dentry, mode, NULL);
+	dentry->d_fsdata = NULL;
+	if (ret)
+		return ERR_PTR(ret);
+
+	filp = dentry_open(dentry, mqueue_mnt, oflag);
+	if (!IS_ERR(filp))
+		dget(dentry);
+
+	return filp;
+}
+
+/* Opens existing queue */
+static struct file *do_open(struct dentry *dentry, int oflag)
+{
+static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
+					MAY_READ | MAY_WRITE };
+	struct file *filp;
+
+	if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
+		return ERR_PTR(-EINVAL);
+
+	if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL))
+		return ERR_PTR(-EACCES);
+
+	filp = dentry_open(dentry, mqueue_mnt, oflag);
+
+	if (!IS_ERR(filp))
+		dget(dentry);
+
+	return filp;
+}
+
+asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
+				struct mq_attr __user *u_attr)
+{
+	struct dentry *dentry;
+	struct file *filp;
+	char *name;
+	int fd, error;
+
+	if (IS_ERR(name = getname(u_name)))
+		return PTR_ERR(name);
+
+	fd = get_unused_fd();
+	if (fd < 0)
+		goto out_putname;
+
+	down(&mqueue_mnt->mnt_root->d_inode->i_sem);
+	dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+	if (IS_ERR(dentry)) {
+		error = PTR_ERR(dentry);
+		goto out_err;
+	}
+	mntget(mqueue_mnt);
+
+	if (oflag & O_CREAT) {
+		if (dentry->d_inode) {	/* entry already exists */
+			filp = (oflag & O_EXCL) ? ERR_PTR(-EEXIST) :
+					do_open(dentry, oflag);
+		} else {
+			filp = do_create(mqueue_mnt->mnt_root, dentry,
+						oflag, mode, u_attr);
+		}
+	} else
+		filp = (dentry->d_inode) ? do_open(dentry, oflag) :
+					ERR_PTR(-ENOENT);
+
+	dput(dentry);
+
+	if (IS_ERR(filp)) {
+		error = PTR_ERR(filp);
+		goto out_putfd;
+	}
+
+	set_close_on_exec(fd, 1);
+	fd_install(fd, filp);
+	goto out_upsem;
+
+out_putfd:
+	mntput(mqueue_mnt);
+	put_unused_fd(fd);
+out_err:
+	fd = error;
+out_upsem:
+	up(&mqueue_mnt->mnt_root->d_inode->i_sem);
+out_putname:
+	putname(name);
+	return fd;
+}
+
+asmlinkage long sys_mq_unlink(const char __user *u_name)
+{
+	int err;
+	char *name;
+	struct dentry *dentry;
+	struct inode *inode = NULL;
+
+	name = getname(u_name);
+	if (IS_ERR(name))
+		return PTR_ERR(name);
+
+	down(&mqueue_mnt->mnt_root->d_inode->i_sem);
+	dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+	if (IS_ERR(dentry)) {
+		err = PTR_ERR(dentry);
+		goto out_unlock;
+	}
+
+	if (!dentry->d_inode) {
+		err = -ENOENT;
+		goto out_err;
+	}
+
+	inode = dentry->d_inode;
+	if (inode)
+		atomic_inc(&inode->i_count);
+
+	err = vfs_unlink(dentry->d_parent->d_inode, dentry);
+out_err:
+	dput(dentry);
+
+out_unlock:
+	up(&mqueue_mnt->mnt_root->d_inode->i_sem);
+	putname(name);
+	if (inode)
+		iput(inode);
+
+	return err;
+}
+
+/* Pipelined send and receive functions.
+ *
+ * If a receiver finds no waiting message, then it registers itself in the
+ * list of waiting receivers. A sender checks that list before adding the new
+ * message into the message array. If there is a waiting receiver, then it
+ * bypasses the message array and directly hands the message over to the
+ * receiver.
+ * The receiver accepts the message and returns without grabbing the queue
+ * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
+ * are necessary. The same algorithm is used for sysv semaphores, see
+ * ipc/sem.c fore more details.
+ *
+ * The same algorithm is used for senders.
+ */
+
+/* pipelined_send() - send a message directly to the task waiting in
+ * sys_mq_timedreceive() (without inserting message into a queue).
+ */
+static inline void pipelined_send(struct mqueue_inode_info *info,
+				  struct msg_msg *message,
+				  struct ext_wait_queue *receiver)
+{
+	receiver->msg = message;
+	list_del(&receiver->list);
+	receiver->state = STATE_PENDING;
+	wake_up_process(receiver->task);
+	wmb();
+	receiver->state = STATE_READY;
+}
+
+/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
+ * gets its message and put to the queue (we have one free place for sure). */
+static inline void pipelined_receive(struct mqueue_inode_info *info)
+{
+	struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
+
+	if (!sender) {
+		/* for poll */
+		wake_up_interruptible(&info->wait_q);
+		return;
+	}
+	msg_insert(sender->msg, info);
+	list_del(&sender->list);
+	sender->state = STATE_PENDING;
+	wake_up_process(sender->task);
+	wmb();
+	sender->state = STATE_READY;
+}
+
+asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
+	size_t msg_len, unsigned int msg_prio,
+	const struct timespec __user *u_abs_timeout)
+{
+	struct file *filp;
+	struct inode *inode;
+	struct ext_wait_queue wait;
+	struct ext_wait_queue *receiver;
+	struct msg_msg *msg_ptr;
+	struct mqueue_inode_info *info;
+	long timeout;
+	int ret;
+
+	if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
+		return -EINVAL;
+
+	timeout = prepare_timeout(u_abs_timeout);
+
+	ret = -EBADF;
+	filp = fget(mqdes);
+	if (unlikely(!filp))
+		goto out;
+
+	inode = filp->f_dentry->d_inode;
+	if (unlikely(filp->f_op != &mqueue_file_operations))
+		goto out_fput;
+	info = MQUEUE_I(inode);
+
+	if (unlikely(!(filp->f_mode & FMODE_WRITE)))
+		goto out_fput;
+
+	if (unlikely(msg_len > info->attr.mq_msgsize)) {
+		ret = -EMSGSIZE;
+		goto out_fput;
+	}
+
+	/* First try to allocate memory, before doing anything with
+	 * existing queues. */
+	msg_ptr = load_msg(u_msg_ptr, msg_len);
+	if (IS_ERR(msg_ptr)) {
+		ret = PTR_ERR(msg_ptr);
+		goto out_fput;
+	}
+	msg_ptr->m_ts = msg_len;
+	msg_ptr->m_type = msg_prio;
+
+	spin_lock(&info->lock);
+
+	if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
+		if (filp->f_flags & O_NONBLOCK) {
+			spin_unlock(&info->lock);
+			ret = -EAGAIN;
+		} else if (unlikely(timeout < 0)) {
+			spin_unlock(&info->lock);
+			ret = timeout;
+		} else {
+			wait.task = current;
+			wait.msg = (void *) msg_ptr;
+			wait.state = STATE_NONE;
+			ret = wq_sleep(info, SEND, timeout, &wait);
+		}
+		if (ret < 0)
+			free_msg(msg_ptr);
+	} else {
+		receiver = wq_get_first_waiter(info, RECV);
+		if (receiver) {
+			pipelined_send(info, msg_ptr, receiver);
+		} else {
+			/* adds message to the queue */
+			msg_insert(msg_ptr, info);
+			__do_notify(info);
+		}
+		inode->i_atime = inode->i_mtime = inode->i_ctime =
+				CURRENT_TIME;
+		spin_unlock(&info->lock);
+		ret = 0;
+	}
+out_fput:
+	fput(filp);
+out:
+	return ret;
+}
+
+asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
+	size_t msg_len, unsigned int __user *u_msg_prio,
+	const struct timespec __user *u_abs_timeout)
+{
+	long timeout;
+	ssize_t ret;
+	struct msg_msg *msg_ptr;
+	struct file *filp;
+	struct inode *inode;
+	struct mqueue_inode_info *info;
+	struct ext_wait_queue wait;
+
+	timeout = prepare_timeout(u_abs_timeout);
+
+	ret = -EBADF;
+	filp = fget(mqdes);
+	if (unlikely(!filp))
+		goto out;
+
+	inode = filp->f_dentry->d_inode;
+	if (unlikely(filp->f_op != &mqueue_file_operations))
+		goto out_fput;
+	info = MQUEUE_I(inode);
+
+	if (unlikely(!(filp->f_mode & FMODE_READ)))
+		goto out_fput;
+
+	/* checks if buffer is big enough */
+	if (unlikely(msg_len < info->attr.mq_msgsize)) {
+		ret = -EMSGSIZE;
+		goto out_fput;
+	}
+
+	spin_lock(&info->lock);
+	if (info->attr.mq_curmsgs == 0) {
+		if (filp->f_flags & O_NONBLOCK) {
+			spin_unlock(&info->lock);
+			ret = -EAGAIN;
+			msg_ptr = NULL;
+		} else if (unlikely(timeout < 0)) {
+			spin_unlock(&info->lock);
+			ret = timeout;
+			msg_ptr = NULL;
+		} else {
+			wait.task = current;
+			wait.state = STATE_NONE;
+			ret = wq_sleep(info, RECV, timeout, &wait);
+			msg_ptr = wait.msg;
+		}
+	} else {
+		msg_ptr = msg_get(info);
+
+		inode->i_atime = inode->i_mtime = inode->i_ctime =
+				CURRENT_TIME;
+
+		/* There is now free space in queue. */
+		pipelined_receive(info);
+		spin_unlock(&info->lock);
+		ret = 0;
+	}
+	if (ret == 0) {
+		ret = msg_ptr->m_ts;
+
+		if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
+			store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
+			ret = -EFAULT;
+		}
+		free_msg(msg_ptr);
+	}
+out_fput:
+	fput(filp);
+out:
+	return ret;
+}
+
+/*
+ * Notes: the case when user wants us to deregister (with NULL as pointer)
+ * and he isn't currently owner of notification, will be silently discarded.
+ * It isn't explicitly defined in the POSIX.
+ */
+asmlinkage long sys_mq_notify(mqd_t mqdes,
+				const struct sigevent __user *u_notification)
+{
+	int ret;
+	struct file *filp;
+	struct sock *sock;
+	struct inode *inode;
+	struct sigevent notification;
+	struct mqueue_inode_info *info;
+	struct sk_buff *nc;
+
+	nc = NULL;
+	sock = NULL;
+	if (u_notification != NULL) {
+		if (copy_from_user(&notification, u_notification,
+					sizeof(struct sigevent)))
+			return -EFAULT;
+
+		if (unlikely(notification.sigev_notify != SIGEV_NONE &&
+			     notification.sigev_notify != SIGEV_SIGNAL &&
+			     notification.sigev_notify != SIGEV_THREAD))
+			return -EINVAL;
+		if (notification.sigev_notify == SIGEV_SIGNAL &&
+			(notification.sigev_signo < 0 ||
+			 notification.sigev_signo > _NSIG)) {
+			return -EINVAL;
+		}
+		if (notification.sigev_notify == SIGEV_THREAD) {
+			/* create the notify skb */
+			nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
+			ret = -ENOMEM;
+			if (!nc)
+				goto out;
+			ret = -EFAULT;
+			if (copy_from_user(nc->data,
+					notification.sigev_value.sival_ptr,
+					NOTIFY_COOKIE_LEN)) {
+				goto out;
+			}
+
+			/* TODO: add a header? */
+			skb_put(nc, NOTIFY_COOKIE_LEN);
+			/* and attach it to the socket */
+retry:
+			filp = fget(notification.sigev_signo);
+			ret = -EBADF;
+			if (!filp)
+				goto out;
+			sock = netlink_getsockbyfilp(filp);
+			fput(filp);
+			if (IS_ERR(sock)) {
+				ret = PTR_ERR(sock);
+				sock = NULL;
+				goto out;
+			}
+
+			ret = netlink_attachskb(sock, nc, 0, MAX_SCHEDULE_TIMEOUT);
+			if (ret == 1)
+		       		goto retry;
+			if (ret) {
+				sock = NULL;
+				nc = NULL;
+				goto out;
+			}
+		}
+	}
+
+	ret = -EBADF;
+	filp = fget(mqdes);
+	if (!filp)
+		goto out;
+
+	inode = filp->f_dentry->d_inode;
+	if (unlikely(filp->f_op != &mqueue_file_operations))
+		goto out_fput;
+	info = MQUEUE_I(inode);
+
+	ret = 0;
+	spin_lock(&info->lock);
+	if (u_notification == NULL) {
+		if (info->notify_owner == current->tgid) {
+			remove_notification(info);
+			inode->i_atime = inode->i_ctime = CURRENT_TIME;
+		}
+	} else if (info->notify_owner != 0) {
+		ret = -EBUSY;
+	} else {
+		switch (notification.sigev_notify) {
+		case SIGEV_NONE:
+			info->notify.sigev_notify = SIGEV_NONE;
+			break;
+		case SIGEV_THREAD:
+			info->notify_sock = sock;
+			info->notify_cookie = nc;
+			sock = NULL;
+			nc = NULL;
+			info->notify.sigev_notify = SIGEV_THREAD;
+			break;
+		case SIGEV_SIGNAL:
+			info->notify.sigev_signo = notification.sigev_signo;
+			info->notify.sigev_value = notification.sigev_value;
+			info->notify.sigev_notify = SIGEV_SIGNAL;
+			break;
+		}
+		info->notify_owner = current->tgid;
+		inode->i_atime = inode->i_ctime = CURRENT_TIME;
+	}
+	spin_unlock(&info->lock);
+out_fput:
+	fput(filp);
+out:
+	if (sock) {
+		netlink_detachskb(sock, nc);
+	} else if (nc) {
+		dev_kfree_skb(nc);
+	}
+	return ret;
+}
+
+asmlinkage long sys_mq_getsetattr(mqd_t mqdes,
+			const struct mq_attr __user *u_mqstat,
+			struct mq_attr __user *u_omqstat)
+{
+	int ret;
+	struct mq_attr mqstat, omqstat;
+	struct file *filp;
+	struct inode *inode;
+	struct mqueue_inode_info *info;
+
+	if (u_mqstat != NULL) {
+		if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr)))
+			return -EFAULT;
+		if (mqstat.mq_flags & (~O_NONBLOCK))
+			return -EINVAL;
+	}
+
+	ret = -EBADF;
+	filp = fget(mqdes);
+	if (!filp)
+		goto out;
+
+	inode = filp->f_dentry->d_inode;
+	if (unlikely(filp->f_op != &mqueue_file_operations))
+		goto out_fput;
+	info = MQUEUE_I(inode);
+
+	spin_lock(&info->lock);
+
+	omqstat = info->attr;
+	omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
+	if (u_mqstat) {
+		if (mqstat.mq_flags & O_NONBLOCK)
+			filp->f_flags |= O_NONBLOCK;
+		else
+			filp->f_flags &= ~O_NONBLOCK;
+
+		inode->i_atime = inode->i_ctime = CURRENT_TIME;
+	}
+
+	spin_unlock(&info->lock);
+
+	ret = 0;
+	if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat,
+						sizeof(struct mq_attr)))
+		ret = -EFAULT;
+
+out_fput:
+	fput(filp);
+out:
+	return ret;
+}
+
+static struct inode_operations mqueue_dir_inode_operations = {
+	.lookup = simple_lookup,
+	.create = mqueue_create,
+	.unlink = mqueue_unlink,
+};
+
+static struct file_operations mqueue_file_operations = {
+	.flush = mqueue_flush_file,
+	.poll = mqueue_poll_file,
+	.read = mqueue_read_file,
+};
+
+static struct super_operations mqueue_super_ops = {
+	.alloc_inode = mqueue_alloc_inode,
+	.destroy_inode = mqueue_destroy_inode,
+	.statfs = simple_statfs,
+	.delete_inode = mqueue_delete_inode,
+	.drop_inode = generic_delete_inode,
+};
+
+static struct file_system_type mqueue_fs_type = {
+	.name = "mqueue",
+	.get_sb = mqueue_get_sb,
+	.kill_sb = kill_litter_super,
+};
+
+static int msg_max_limit_min = DFLT_MSGMAX;
+static int msg_max_limit_max = HARD_MSGMAX;
+
+static int msg_maxsize_limit_min = DFLT_MSGSIZEMAX;
+static int msg_maxsize_limit_max = INT_MAX;
+
+static ctl_table mq_sysctls[] = {
+	{
+		.ctl_name	= CTL_QUEUESMAX,
+		.procname	= "queues_max",
+		.data		= &queues_max,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= CTL_MSGMAX,
+		.procname	= "msg_max",
+		.data		= &msg_max,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.extra1		= &msg_max_limit_min,
+		.extra2		= &msg_max_limit_max,
+	},
+	{
+		.ctl_name	= CTL_MSGSIZEMAX,
+		.procname	= "msgsize_max",
+		.data		= &msgsize_max,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.extra1		= &msg_maxsize_limit_min,
+		.extra2		= &msg_maxsize_limit_max,
+	},
+	{ .ctl_name = 0 }
+};
+
+static ctl_table mq_sysctl_dir[] = {
+	{
+		.ctl_name	= FS_MQUEUE,
+		.procname	= "mqueue",
+		.mode		= 0555,
+		.child		= mq_sysctls,
+	},
+	{ .ctl_name = 0 }
+};
+
+static ctl_table mq_sysctl_root[] = {
+	{
+		.ctl_name	= CTL_FS,
+		.procname	= "fs",
+		.mode		= 0555,
+		.child		= mq_sysctl_dir,
+	},
+	{ .ctl_name = 0 }
+};
+
+static int __init init_mqueue_fs(void)
+{
+	int error;
+
+	mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
+				sizeof(struct mqueue_inode_info), 0,
+				SLAB_HWCACHE_ALIGN, init_once, NULL);
+	if (mqueue_inode_cachep == NULL)
+		return -ENOMEM;
+
+	/* ignore failues - they are not fatal */
+	mq_sysctl_table = register_sysctl_table(mq_sysctl_root, 0);
+
+	error = register_filesystem(&mqueue_fs_type);
+	if (error)
+		goto out_sysctl;
+
+	if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) {
+		error = PTR_ERR(mqueue_mnt);
+		goto out_filesystem;
+	}
+
+	/* internal initialization - not common for vfs */
+	queues_count = 0;
+	spin_lock_init(&mq_lock);
+
+	return 0;
+
+out_filesystem:
+	unregister_filesystem(&mqueue_fs_type);
+out_sysctl:
+	if (mq_sysctl_table)
+		unregister_sysctl_table(mq_sysctl_table);
+	if (kmem_cache_destroy(mqueue_inode_cachep)) {
+		printk(KERN_INFO
+			"mqueue_inode_cache: not all structures were freed\n");
+	}
+	return error;
+}
+
+__initcall(init_mqueue_fs);
diff --git a/ipc/msg.c b/ipc/msg.c
new file mode 100644
index 0000000..27e516f
--- /dev/null
+++ b/ipc/msg.c
@@ -0,0 +1,862 @@
+/*
+ * linux/ipc/msg.c
+ * Copyright (C) 1992 Krishna Balasubramanian 
+ *
+ * Removed all the remaining kerneld mess
+ * Catch the -EFAULT stuff properly
+ * Use GFP_KERNEL for messages as in 1.2
+ * Fixed up the unchecked user space derefs
+ * Copyright (C) 1998 Alan Cox & Andi Kleen
+ *
+ * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
+ *
+ * mostly rewritten, threaded and wake-one semantics added
+ * MSGMAX limit removed, sysctl's added
+ * (c) 1999 Manfred Spraul <manfreds@colorfullife.com>
+ */
+
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/msg.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/list.h>
+#include <linux/security.h>
+#include <linux/sched.h>
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+#include <asm/current.h>
+#include <asm/uaccess.h>
+#include "util.h"
+
+/* sysctl: */
+int msg_ctlmax = MSGMAX;
+int msg_ctlmnb = MSGMNB;
+int msg_ctlmni = MSGMNI;
+
+/* one msg_receiver structure for each sleeping receiver */
+struct msg_receiver {
+	struct list_head r_list;
+	struct task_struct* r_tsk;
+
+	int r_mode;
+	long r_msgtype;
+	long r_maxsize;
+
+	struct msg_msg* volatile r_msg;
+};
+
+/* one msg_sender for each sleeping sender */
+struct msg_sender {
+	struct list_head list;
+	struct task_struct* tsk;
+};
+
+#define SEARCH_ANY		1
+#define SEARCH_EQUAL		2
+#define SEARCH_NOTEQUAL		3
+#define SEARCH_LESSEQUAL	4
+
+static atomic_t msg_bytes = ATOMIC_INIT(0);
+static atomic_t msg_hdrs = ATOMIC_INIT(0);
+
+static struct ipc_ids msg_ids;
+
+#define msg_lock(id)	((struct msg_queue*)ipc_lock(&msg_ids,id))
+#define msg_unlock(msq)	ipc_unlock(&(msq)->q_perm)
+#define msg_rmid(id)	((struct msg_queue*)ipc_rmid(&msg_ids,id))
+#define msg_checkid(msq, msgid)	\
+	ipc_checkid(&msg_ids,&msq->q_perm,msgid)
+#define msg_buildid(id, seq) \
+	ipc_buildid(&msg_ids, id, seq)
+
+static void freeque (struct msg_queue *msq, int id);
+static int newque (key_t key, int msgflg);
+#ifdef CONFIG_PROC_FS
+static int sysvipc_msg_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data);
+#endif
+
+void __init msg_init (void)
+{
+	ipc_init_ids(&msg_ids,msg_ctlmni);
+
+#ifdef CONFIG_PROC_FS
+	create_proc_read_entry("sysvipc/msg", 0, NULL, sysvipc_msg_read_proc, NULL);
+#endif
+}
+
+static int newque (key_t key, int msgflg)
+{
+	int id;
+	int retval;
+	struct msg_queue *msq;
+
+	msq  = ipc_rcu_alloc(sizeof(*msq));
+	if (!msq) 
+		return -ENOMEM;
+
+	msq->q_perm.mode = (msgflg & S_IRWXUGO);
+	msq->q_perm.key = key;
+
+	msq->q_perm.security = NULL;
+	retval = security_msg_queue_alloc(msq);
+	if (retval) {
+		ipc_rcu_putref(msq);
+		return retval;
+	}
+
+	id = ipc_addid(&msg_ids, &msq->q_perm, msg_ctlmni);
+	if(id == -1) {
+		security_msg_queue_free(msq);
+		ipc_rcu_putref(msq);
+		return -ENOSPC;
+	}
+
+	msq->q_stime = msq->q_rtime = 0;
+	msq->q_ctime = get_seconds();
+	msq->q_cbytes = msq->q_qnum = 0;
+	msq->q_qbytes = msg_ctlmnb;
+	msq->q_lspid = msq->q_lrpid = 0;
+	INIT_LIST_HEAD(&msq->q_messages);
+	INIT_LIST_HEAD(&msq->q_receivers);
+	INIT_LIST_HEAD(&msq->q_senders);
+	msg_unlock(msq);
+
+	return msg_buildid(id,msq->q_perm.seq);
+}
+
+static inline void ss_add(struct msg_queue* msq, struct msg_sender* mss)
+{
+	mss->tsk=current;
+	current->state=TASK_INTERRUPTIBLE;
+	list_add_tail(&mss->list,&msq->q_senders);
+}
+
+static inline void ss_del(struct msg_sender* mss)
+{
+	if(mss->list.next != NULL)
+		list_del(&mss->list);
+}
+
+static void ss_wakeup(struct list_head* h, int kill)
+{
+	struct list_head *tmp;
+
+	tmp = h->next;
+	while (tmp != h) {
+		struct msg_sender* mss;
+		
+		mss = list_entry(tmp,struct msg_sender,list);
+		tmp = tmp->next;
+		if(kill)
+			mss->list.next=NULL;
+		wake_up_process(mss->tsk);
+	}
+}
+
+static void expunge_all(struct msg_queue* msq, int res)
+{
+	struct list_head *tmp;
+
+	tmp = msq->q_receivers.next;
+	while (tmp != &msq->q_receivers) {
+		struct msg_receiver* msr;
+		
+		msr = list_entry(tmp,struct msg_receiver,r_list);
+		tmp = tmp->next;
+		msr->r_msg = NULL;
+		wake_up_process(msr->r_tsk);
+		smp_mb();
+		msr->r_msg = ERR_PTR(res);
+	}
+}
+/* 
+ * freeque() wakes up waiters on the sender and receiver waiting queue, 
+ * removes the message queue from message queue ID 
+ * array, and cleans up all the messages associated with this queue.
+ *
+ * msg_ids.sem and the spinlock for this message queue is hold
+ * before freeque() is called. msg_ids.sem remains locked on exit.
+ */
+static void freeque (struct msg_queue *msq, int id)
+{
+	struct list_head *tmp;
+
+	expunge_all(msq,-EIDRM);
+	ss_wakeup(&msq->q_senders,1);
+	msq = msg_rmid(id);
+	msg_unlock(msq);
+		
+	tmp = msq->q_messages.next;
+	while(tmp != &msq->q_messages) {
+		struct msg_msg* msg = list_entry(tmp,struct msg_msg,m_list);
+		tmp = tmp->next;
+		atomic_dec(&msg_hdrs);
+		free_msg(msg);
+	}
+	atomic_sub(msq->q_cbytes, &msg_bytes);
+	security_msg_queue_free(msq);
+	ipc_rcu_putref(msq);
+}
+
+asmlinkage long sys_msgget (key_t key, int msgflg)
+{
+	int id, ret = -EPERM;
+	struct msg_queue *msq;
+	
+	down(&msg_ids.sem);
+	if (key == IPC_PRIVATE) 
+		ret = newque(key, msgflg);
+	else if ((id = ipc_findkey(&msg_ids, key)) == -1) { /* key not used */
+		if (!(msgflg & IPC_CREAT))
+			ret = -ENOENT;
+		else
+			ret = newque(key, msgflg);
+	} else if (msgflg & IPC_CREAT && msgflg & IPC_EXCL) {
+		ret = -EEXIST;
+	} else {
+		msq = msg_lock(id);
+		if(msq==NULL)
+			BUG();
+		if (ipcperms(&msq->q_perm, msgflg))
+			ret = -EACCES;
+		else {
+			int qid = msg_buildid(id, msq->q_perm.seq);
+		    	ret = security_msg_queue_associate(msq, msgflg);
+			if (!ret)
+				ret = qid;
+		}
+		msg_unlock(msq);
+	}
+	up(&msg_ids.sem);
+	return ret;
+}
+
+static inline unsigned long copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
+{
+	switch(version) {
+	case IPC_64:
+		return copy_to_user (buf, in, sizeof(*in));
+	case IPC_OLD:
+	    {
+		struct msqid_ds out;
+
+		memset(&out,0,sizeof(out));
+
+		ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
+
+		out.msg_stime		= in->msg_stime;
+		out.msg_rtime		= in->msg_rtime;
+		out.msg_ctime		= in->msg_ctime;
+
+		if(in->msg_cbytes > USHRT_MAX)
+			out.msg_cbytes	= USHRT_MAX;
+		else
+			out.msg_cbytes	= in->msg_cbytes;
+		out.msg_lcbytes		= in->msg_cbytes;
+
+		if(in->msg_qnum > USHRT_MAX)
+			out.msg_qnum	= USHRT_MAX;
+		else
+			out.msg_qnum	= in->msg_qnum;
+
+		if(in->msg_qbytes > USHRT_MAX)
+			out.msg_qbytes	= USHRT_MAX;
+		else
+			out.msg_qbytes	= in->msg_qbytes;
+		out.msg_lqbytes		= in->msg_qbytes;
+
+		out.msg_lspid		= in->msg_lspid;
+		out.msg_lrpid		= in->msg_lrpid;
+
+		return copy_to_user (buf, &out, sizeof(out));
+	    }
+	default:
+		return -EINVAL;
+	}
+}
+
+struct msq_setbuf {
+	unsigned long	qbytes;
+	uid_t		uid;
+	gid_t		gid;
+	mode_t		mode;
+};
+
+static inline unsigned long copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version)
+{
+	switch(version) {
+	case IPC_64:
+	    {
+		struct msqid64_ds tbuf;
+
+		if (copy_from_user (&tbuf, buf, sizeof (tbuf)))
+			return -EFAULT;
+
+		out->qbytes		= tbuf.msg_qbytes;
+		out->uid		= tbuf.msg_perm.uid;
+		out->gid		= tbuf.msg_perm.gid;
+		out->mode		= tbuf.msg_perm.mode;
+
+		return 0;
+	    }
+	case IPC_OLD:
+	    {
+		struct msqid_ds tbuf_old;
+
+		if (copy_from_user (&tbuf_old, buf, sizeof (tbuf_old)))
+			return -EFAULT;
+
+		out->uid		= tbuf_old.msg_perm.uid;
+		out->gid		= tbuf_old.msg_perm.gid;
+		out->mode		= tbuf_old.msg_perm.mode;
+
+		if(tbuf_old.msg_qbytes == 0)
+			out->qbytes	= tbuf_old.msg_lqbytes;
+		else
+			out->qbytes	= tbuf_old.msg_qbytes;
+
+		return 0;
+	    }
+	default:
+		return -EINVAL;
+	}
+}
+
+asmlinkage long sys_msgctl (int msqid, int cmd, struct msqid_ds __user *buf)
+{
+	int err, version;
+	struct msg_queue *msq;
+	struct msq_setbuf setbuf;
+	struct kern_ipc_perm *ipcp;
+	
+	if (msqid < 0 || cmd < 0)
+		return -EINVAL;
+
+	version = ipc_parse_version(&cmd);
+
+	switch (cmd) {
+	case IPC_INFO: 
+	case MSG_INFO: 
+	{ 
+		struct msginfo msginfo;
+		int max_id;
+		if (!buf)
+			return -EFAULT;
+		/* We must not return kernel stack data.
+		 * due to padding, it's not enough
+		 * to set all member fields.
+		 */
+
+		err = security_msg_queue_msgctl(NULL, cmd);
+		if (err)
+			return err;
+
+		memset(&msginfo,0,sizeof(msginfo));	
+		msginfo.msgmni = msg_ctlmni;
+		msginfo.msgmax = msg_ctlmax;
+		msginfo.msgmnb = msg_ctlmnb;
+		msginfo.msgssz = MSGSSZ;
+		msginfo.msgseg = MSGSEG;
+		down(&msg_ids.sem);
+		if (cmd == MSG_INFO) {
+			msginfo.msgpool = msg_ids.in_use;
+			msginfo.msgmap = atomic_read(&msg_hdrs);
+			msginfo.msgtql = atomic_read(&msg_bytes);
+		} else {
+			msginfo.msgmap = MSGMAP;
+			msginfo.msgpool = MSGPOOL;
+			msginfo.msgtql = MSGTQL;
+		}
+		max_id = msg_ids.max_id;
+		up(&msg_ids.sem);
+		if (copy_to_user (buf, &msginfo, sizeof(struct msginfo)))
+			return -EFAULT;
+		return (max_id < 0) ? 0: max_id;
+	}
+	case MSG_STAT:
+	case IPC_STAT:
+	{
+		struct msqid64_ds tbuf;
+		int success_return;
+		if (!buf)
+			return -EFAULT;
+		if(cmd == MSG_STAT && msqid >= msg_ids.entries->size)
+			return -EINVAL;
+
+		memset(&tbuf,0,sizeof(tbuf));
+
+		msq = msg_lock(msqid);
+		if (msq == NULL)
+			return -EINVAL;
+
+		if(cmd == MSG_STAT) {
+			success_return = msg_buildid(msqid, msq->q_perm.seq);
+		} else {
+			err = -EIDRM;
+			if (msg_checkid(msq,msqid))
+				goto out_unlock;
+			success_return = 0;
+		}
+		err = -EACCES;
+		if (ipcperms (&msq->q_perm, S_IRUGO))
+			goto out_unlock;
+
+		err = security_msg_queue_msgctl(msq, cmd);
+		if (err)
+			goto out_unlock;
+
+		kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
+		tbuf.msg_stime  = msq->q_stime;
+		tbuf.msg_rtime  = msq->q_rtime;
+		tbuf.msg_ctime  = msq->q_ctime;
+		tbuf.msg_cbytes = msq->q_cbytes;
+		tbuf.msg_qnum   = msq->q_qnum;
+		tbuf.msg_qbytes = msq->q_qbytes;
+		tbuf.msg_lspid  = msq->q_lspid;
+		tbuf.msg_lrpid  = msq->q_lrpid;
+		msg_unlock(msq);
+		if (copy_msqid_to_user(buf, &tbuf, version))
+			return -EFAULT;
+		return success_return;
+	}
+	case IPC_SET:
+		if (!buf)
+			return -EFAULT;
+		if (copy_msqid_from_user (&setbuf, buf, version))
+			return -EFAULT;
+		if ((err = audit_ipc_perms(setbuf.qbytes, setbuf.uid, setbuf.gid, setbuf.mode)))
+			return err;
+		break;
+	case IPC_RMID:
+		break;
+	default:
+		return  -EINVAL;
+	}
+
+	down(&msg_ids.sem);
+	msq = msg_lock(msqid);
+	err=-EINVAL;
+	if (msq == NULL)
+		goto out_up;
+
+	err = -EIDRM;
+	if (msg_checkid(msq,msqid))
+		goto out_unlock_up;
+	ipcp = &msq->q_perm;
+	err = -EPERM;
+	if (current->euid != ipcp->cuid && 
+	    current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN))
+	    /* We _could_ check for CAP_CHOWN above, but we don't */
+		goto out_unlock_up;
+
+	err = security_msg_queue_msgctl(msq, cmd);
+	if (err)
+		goto out_unlock_up;
+
+	switch (cmd) {
+	case IPC_SET:
+	{
+		err = -EPERM;
+		if (setbuf.qbytes > msg_ctlmnb && !capable(CAP_SYS_RESOURCE))
+			goto out_unlock_up;
+
+		msq->q_qbytes = setbuf.qbytes;
+
+		ipcp->uid = setbuf.uid;
+		ipcp->gid = setbuf.gid;
+		ipcp->mode = (ipcp->mode & ~S_IRWXUGO) | 
+			(S_IRWXUGO & setbuf.mode);
+		msq->q_ctime = get_seconds();
+		/* sleeping receivers might be excluded by
+		 * stricter permissions.
+		 */
+		expunge_all(msq,-EAGAIN);
+		/* sleeping senders might be able to send
+		 * due to a larger queue size.
+		 */
+		ss_wakeup(&msq->q_senders,0);
+		msg_unlock(msq);
+		break;
+	}
+	case IPC_RMID:
+		freeque (msq, msqid); 
+		break;
+	}
+	err = 0;
+out_up:
+	up(&msg_ids.sem);
+	return err;
+out_unlock_up:
+	msg_unlock(msq);
+	goto out_up;
+out_unlock:
+	msg_unlock(msq);
+	return err;
+}
+
+static int testmsg(struct msg_msg* msg,long type,int mode)
+{
+	switch(mode)
+	{
+		case SEARCH_ANY:
+			return 1;
+		case SEARCH_LESSEQUAL:
+			if(msg->m_type <=type)
+				return 1;
+			break;
+		case SEARCH_EQUAL:
+			if(msg->m_type == type)
+				return 1;
+			break;
+		case SEARCH_NOTEQUAL:
+			if(msg->m_type != type)
+				return 1;
+			break;
+	}
+	return 0;
+}
+
+static inline int pipelined_send(struct msg_queue* msq, struct msg_msg* msg)
+{
+	struct list_head* tmp;
+
+	tmp = msq->q_receivers.next;
+	while (tmp != &msq->q_receivers) {
+		struct msg_receiver* msr;
+		msr = list_entry(tmp,struct msg_receiver,r_list);
+		tmp = tmp->next;
+		if(testmsg(msg,msr->r_msgtype,msr->r_mode) &&
+		   !security_msg_queue_msgrcv(msq, msg, msr->r_tsk, msr->r_msgtype, msr->r_mode)) {
+			list_del(&msr->r_list);
+			if(msr->r_maxsize < msg->m_ts) {
+				msr->r_msg = NULL;
+				wake_up_process(msr->r_tsk);
+				smp_mb();
+				msr->r_msg = ERR_PTR(-E2BIG);
+			} else {
+				msr->r_msg = NULL;
+				msq->q_lrpid = msr->r_tsk->pid;
+				msq->q_rtime = get_seconds();
+				wake_up_process(msr->r_tsk);
+				smp_mb();
+				msr->r_msg = msg;
+				return 1;
+			}
+		}
+	}
+	return 0;
+}
+
+asmlinkage long sys_msgsnd (int msqid, struct msgbuf __user *msgp, size_t msgsz, int msgflg)
+{
+	struct msg_queue *msq;
+	struct msg_msg *msg;
+	long mtype;
+	int err;
+	
+	if (msgsz > msg_ctlmax || (long) msgsz < 0 || msqid < 0)
+		return -EINVAL;
+	if (get_user(mtype, &msgp->mtype))
+		return -EFAULT; 
+	if (mtype < 1)
+		return -EINVAL;
+
+	msg = load_msg(msgp->mtext, msgsz);
+	if(IS_ERR(msg))
+		return PTR_ERR(msg);
+
+	msg->m_type = mtype;
+	msg->m_ts = msgsz;
+
+	msq = msg_lock(msqid);
+	err=-EINVAL;
+	if(msq==NULL)
+		goto out_free;
+
+	err= -EIDRM;
+	if (msg_checkid(msq,msqid))
+		goto out_unlock_free;
+
+	for (;;) {
+		struct msg_sender s;
+
+		err=-EACCES;
+		if (ipcperms(&msq->q_perm, S_IWUGO))
+			goto out_unlock_free;
+
+		err = security_msg_queue_msgsnd(msq, msg, msgflg);
+		if (err)
+			goto out_unlock_free;
+
+		if(msgsz + msq->q_cbytes <= msq->q_qbytes &&
+				1 + msq->q_qnum <= msq->q_qbytes) {
+			break;
+		}
+
+		/* queue full, wait: */
+		if(msgflg&IPC_NOWAIT) {
+			err=-EAGAIN;
+			goto out_unlock_free;
+		}
+		ss_add(msq, &s);
+		ipc_rcu_getref(msq);
+		msg_unlock(msq);
+		schedule();
+
+		ipc_lock_by_ptr(&msq->q_perm);
+		ipc_rcu_putref(msq);
+		if (msq->q_perm.deleted) {
+			err = -EIDRM;
+			goto out_unlock_free;
+		}
+		ss_del(&s);
+		
+		if (signal_pending(current)) {
+			err=-ERESTARTNOHAND;
+			goto out_unlock_free;
+		}
+	}
+
+	msq->q_lspid = current->tgid;
+	msq->q_stime = get_seconds();
+
+	if(!pipelined_send(msq,msg)) {
+		/* noone is waiting for this message, enqueue it */
+		list_add_tail(&msg->m_list,&msq->q_messages);
+		msq->q_cbytes += msgsz;
+		msq->q_qnum++;
+		atomic_add(msgsz,&msg_bytes);
+		atomic_inc(&msg_hdrs);
+	}
+	
+	err = 0;
+	msg = NULL;
+
+out_unlock_free:
+	msg_unlock(msq);
+out_free:
+	if(msg!=NULL)
+		free_msg(msg);
+	return err;
+}
+
+static inline int convert_mode(long* msgtyp, int msgflg)
+{
+	/* 
+	 *  find message of correct type.
+	 *  msgtyp = 0 => get first.
+	 *  msgtyp > 0 => get first message of matching type.
+	 *  msgtyp < 0 => get message with least type must be < abs(msgtype).  
+	 */
+	if(*msgtyp==0)
+		return SEARCH_ANY;
+	if(*msgtyp<0) {
+		*msgtyp=-(*msgtyp);
+		return SEARCH_LESSEQUAL;
+	}
+	if(msgflg & MSG_EXCEPT)
+		return SEARCH_NOTEQUAL;
+	return SEARCH_EQUAL;
+}
+
+asmlinkage long sys_msgrcv (int msqid, struct msgbuf __user *msgp, size_t msgsz,
+			    long msgtyp, int msgflg)
+{
+	struct msg_queue *msq;
+	struct msg_msg *msg;
+	int mode;
+
+	if (msqid < 0 || (long) msgsz < 0)
+		return -EINVAL;
+	mode = convert_mode(&msgtyp,msgflg);
+
+	msq = msg_lock(msqid);
+	if(msq==NULL)
+		return -EINVAL;
+
+	msg = ERR_PTR(-EIDRM);
+	if (msg_checkid(msq,msqid))
+		goto out_unlock;
+
+	for (;;) {
+		struct msg_receiver msr_d;
+		struct list_head* tmp;
+
+		msg = ERR_PTR(-EACCES);
+		if (ipcperms (&msq->q_perm, S_IRUGO))
+			goto out_unlock;
+
+		msg = ERR_PTR(-EAGAIN);
+		tmp = msq->q_messages.next;
+		while (tmp != &msq->q_messages) {
+			struct msg_msg *walk_msg;
+			walk_msg = list_entry(tmp,struct msg_msg,m_list);
+			if(testmsg(walk_msg,msgtyp,mode) &&
+			   !security_msg_queue_msgrcv(msq, walk_msg, current, msgtyp, mode)) {
+				msg = walk_msg;
+				if(mode == SEARCH_LESSEQUAL && walk_msg->m_type != 1) {
+					msg=walk_msg;
+					msgtyp=walk_msg->m_type-1;
+				} else {
+					msg=walk_msg;
+					break;
+				}
+			}
+			tmp = tmp->next;
+		}
+		if(!IS_ERR(msg)) {
+			/* Found a suitable message. Unlink it from the queue. */
+			if ((msgsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
+				msg = ERR_PTR(-E2BIG);
+				goto out_unlock;
+			}
+			list_del(&msg->m_list);
+			msq->q_qnum--;
+			msq->q_rtime = get_seconds();
+			msq->q_lrpid = current->tgid;
+			msq->q_cbytes -= msg->m_ts;
+			atomic_sub(msg->m_ts,&msg_bytes);
+			atomic_dec(&msg_hdrs);
+			ss_wakeup(&msq->q_senders,0);
+			msg_unlock(msq);
+			break;
+		}
+		/* No message waiting. Wait for a message */
+		if (msgflg & IPC_NOWAIT) {
+			msg = ERR_PTR(-ENOMSG);
+			goto out_unlock;
+		}
+		list_add_tail(&msr_d.r_list,&msq->q_receivers);
+		msr_d.r_tsk = current;
+		msr_d.r_msgtype = msgtyp;
+		msr_d.r_mode = mode;
+		if(msgflg & MSG_NOERROR)
+			msr_d.r_maxsize = INT_MAX;
+		 else
+			msr_d.r_maxsize = msgsz;
+		msr_d.r_msg = ERR_PTR(-EAGAIN);
+		current->state = TASK_INTERRUPTIBLE;
+		msg_unlock(msq);
+
+		schedule();
+
+		/* Lockless receive, part 1:
+		 * Disable preemption.  We don't hold a reference to the queue
+		 * and getting a reference would defeat the idea of a lockless
+		 * operation, thus the code relies on rcu to guarantee the
+		 * existance of msq:
+		 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
+		 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
+		 * rcu_read_lock() prevents preemption between reading r_msg
+		 * and the spin_lock() inside ipc_lock_by_ptr().
+		 */
+		rcu_read_lock();
+
+		/* Lockless receive, part 2:
+		 * Wait until pipelined_send or expunge_all are outside of
+		 * wake_up_process(). There is a race with exit(), see
+		 * ipc/mqueue.c for the details.
+		 */
+		msg = (struct msg_msg*) msr_d.r_msg;
+		while (msg == NULL) {
+			cpu_relax();
+			msg = (struct msg_msg*) msr_d.r_msg;
+		}
+
+		/* Lockless receive, part 3:
+		 * If there is a message or an error then accept it without
+		 * locking.
+		 */
+		if(msg != ERR_PTR(-EAGAIN)) {
+			rcu_read_unlock();
+			break;
+		}
+
+		/* Lockless receive, part 3:
+		 * Acquire the queue spinlock.
+		 */
+		ipc_lock_by_ptr(&msq->q_perm);
+		rcu_read_unlock();
+
+		/* Lockless receive, part 4:
+		 * Repeat test after acquiring the spinlock.
+		 */
+		msg = (struct msg_msg*)msr_d.r_msg;
+		if(msg != ERR_PTR(-EAGAIN))
+			goto out_unlock;
+
+		list_del(&msr_d.r_list);
+		if (signal_pending(current)) {
+			msg = ERR_PTR(-ERESTARTNOHAND);
+out_unlock:
+			msg_unlock(msq);
+			break;
+		}
+	}
+	if (IS_ERR(msg))
+       		return PTR_ERR(msg);
+
+	msgsz = (msgsz > msg->m_ts) ? msg->m_ts : msgsz;
+	if (put_user (msg->m_type, &msgp->mtype) ||
+	    store_msg(msgp->mtext, msg, msgsz)) {
+		    msgsz = -EFAULT;
+	}
+	free_msg(msg);
+	return msgsz;
+}
+
+#ifdef CONFIG_PROC_FS
+static int sysvipc_msg_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
+{
+	off_t pos = 0;
+	off_t begin = 0;
+	int i, len = 0;
+
+	down(&msg_ids.sem);
+	len += sprintf(buffer, "       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n");
+
+	for(i = 0; i <= msg_ids.max_id; i++) {
+		struct msg_queue * msq;
+		msq = msg_lock(i);
+		if(msq != NULL) {
+			len += sprintf(buffer + len, "%10d %10d  %4o  %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
+				msq->q_perm.key,
+				msg_buildid(i,msq->q_perm.seq),
+				msq->q_perm.mode,
+				msq->q_cbytes,
+				msq->q_qnum,
+				msq->q_lspid,
+				msq->q_lrpid,
+				msq->q_perm.uid,
+				msq->q_perm.gid,
+				msq->q_perm.cuid,
+				msq->q_perm.cgid,
+				msq->q_stime,
+				msq->q_rtime,
+				msq->q_ctime);
+			msg_unlock(msq);
+
+			pos += len;
+			if(pos < offset) {
+				len = 0;
+				begin = pos;
+			}
+			if(pos > offset + length)
+				goto done;
+		}
+
+	}
+	*eof = 1;
+done:
+	up(&msg_ids.sem);
+	*start = buffer + (offset - begin);
+	len -= (offset - begin);
+	if(len > length)
+		len = length;
+	if(len < 0)
+		len = 0;
+	return len;
+}
+#endif
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
new file mode 100644
index 0000000..66cfb87
--- /dev/null
+++ b/ipc/msgutil.c
@@ -0,0 +1,127 @@
+/*
+ * linux/ipc/util.c
+ * Copyright (C) 1999, 2004 Manfred Spraul
+ *
+ * This file is released under GNU General Public Licence version 2 or
+ * (at your option) any later version.
+ *
+ * See the file COPYING for more details.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/security.h>
+#include <linux/slab.h>
+#include <linux/ipc.h>
+#include <asm/uaccess.h>
+
+#include "util.h"
+
+struct msg_msgseg {
+	struct msg_msgseg* next;
+	/* the next part of the message follows immediately */
+};
+
+#define DATALEN_MSG	(PAGE_SIZE-sizeof(struct msg_msg))
+#define DATALEN_SEG	(PAGE_SIZE-sizeof(struct msg_msgseg))
+
+struct msg_msg *load_msg(const void __user *src, int len)
+{
+	struct msg_msg *msg;
+	struct msg_msgseg **pseg;
+	int err;
+	int alen;
+
+	alen = len;
+	if (alen > DATALEN_MSG)
+		alen = DATALEN_MSG;
+
+	msg = (struct msg_msg *)kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
+	if (msg == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	msg->next = NULL;
+	msg->security = NULL;
+
+	if (copy_from_user(msg + 1, src, alen)) {
+		err = -EFAULT;
+		goto out_err;
+	}
+
+	len -= alen;
+	src = ((char __user *)src) + alen;
+	pseg = &msg->next;
+	while (len > 0) {
+		struct msg_msgseg *seg;
+		alen = len;
+		if (alen > DATALEN_SEG)
+			alen = DATALEN_SEG;
+		seg = (struct msg_msgseg *)kmalloc(sizeof(*seg) + alen,
+						 GFP_KERNEL);
+		if (seg == NULL) {
+			err = -ENOMEM;
+			goto out_err;
+		}
+		*pseg = seg;
+		seg->next = NULL;
+		if (copy_from_user(seg + 1, src, alen)) {
+			err = -EFAULT;
+			goto out_err;
+		}
+		pseg = &seg->next;
+		len -= alen;
+		src = ((char __user *)src) + alen;
+	}
+
+	err = security_msg_msg_alloc(msg);
+	if (err)
+		goto out_err;
+
+	return msg;
+
+out_err:
+	free_msg(msg);
+	return ERR_PTR(err);
+}
+
+int store_msg(void __user *dest, struct msg_msg *msg, int len)
+{
+	int alen;
+	struct msg_msgseg *seg;
+
+	alen = len;
+	if (alen > DATALEN_MSG)
+		alen = DATALEN_MSG;
+	if (copy_to_user(dest, msg + 1, alen))
+		return -1;
+
+	len -= alen;
+	dest = ((char __user *)dest) + alen;
+	seg = msg->next;
+	while (len > 0) {
+		alen = len;
+		if (alen > DATALEN_SEG)
+			alen = DATALEN_SEG;
+		if (copy_to_user(dest, seg + 1, alen))
+			return -1;
+		len -= alen;
+		dest = ((char __user *)dest) + alen;
+		seg = seg->next;
+	}
+	return 0;
+}
+
+void free_msg(struct msg_msg *msg)
+{
+	struct msg_msgseg *seg;
+
+	security_msg_msg_free(msg);
+
+	seg = msg->next;
+	kfree(msg);
+	while (seg != NULL) {
+		struct msg_msgseg *tmp = seg->next;
+		kfree(seg);
+		seg = tmp;
+	}
+}
diff --git a/ipc/sem.c b/ipc/sem.c
new file mode 100644
index 0000000..5ad7ac0
--- /dev/null
+++ b/ipc/sem.c
@@ -0,0 +1,1384 @@
+/*
+ * linux/ipc/sem.c
+ * Copyright (C) 1992 Krishna Balasubramanian
+ * Copyright (C) 1995 Eric Schenk, Bruno Haible
+ *
+ * IMPLEMENTATION NOTES ON CODE REWRITE (Eric Schenk, January 1995):
+ * This code underwent a massive rewrite in order to solve some problems
+ * with the original code. In particular the original code failed to
+ * wake up processes that were waiting for semval to go to 0 if the
+ * value went to 0 and was then incremented rapidly enough. In solving
+ * this problem I have also modified the implementation so that it
+ * processes pending operations in a FIFO manner, thus give a guarantee
+ * that processes waiting for a lock on the semaphore won't starve
+ * unless another locking process fails to unlock.
+ * In addition the following two changes in behavior have been introduced:
+ * - The original implementation of semop returned the value
+ *   last semaphore element examined on success. This does not
+ *   match the manual page specifications, and effectively
+ *   allows the user to read the semaphore even if they do not
+ *   have read permissions. The implementation now returns 0
+ *   on success as stated in the manual page.
+ * - There is some confusion over whether the set of undo adjustments
+ *   to be performed at exit should be done in an atomic manner.
+ *   That is, if we are attempting to decrement the semval should we queue
+ *   up and wait until we can do so legally?
+ *   The original implementation attempted to do this.
+ *   The current implementation does not do so. This is because I don't
+ *   think it is the right thing (TM) to do, and because I couldn't
+ *   see a clean way to get the old behavior with the new design.
+ *   The POSIX standard and SVID should be consulted to determine
+ *   what behavior is mandated.
+ *
+ * Further notes on refinement (Christoph Rohland, December 1998):
+ * - The POSIX standard says, that the undo adjustments simply should
+ *   redo. So the current implementation is o.K.
+ * - The previous code had two flaws:
+ *   1) It actively gave the semaphore to the next waiting process
+ *      sleeping on the semaphore. Since this process did not have the
+ *      cpu this led to many unnecessary context switches and bad
+ *      performance. Now we only check which process should be able to
+ *      get the semaphore and if this process wants to reduce some
+ *      semaphore value we simply wake it up without doing the
+ *      operation. So it has to try to get it later. Thus e.g. the
+ *      running process may reacquire the semaphore during the current
+ *      time slice. If it only waits for zero or increases the semaphore,
+ *      we do the operation in advance and wake it up.
+ *   2) It did not wake up all zero waiting processes. We try to do
+ *      better but only get the semops right which only wait for zero or
+ *      increase. If there are decrement operations in the operations
+ *      array we do the same as before.
+ *
+ * With the incarnation of O(1) scheduler, it becomes unnecessary to perform
+ * check/retry algorithm for waking up blocked processes as the new scheduler
+ * is better at handling thread switch than the old one.
+ *
+ * /proc/sysvipc/sem support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
+ *
+ * SMP-threaded, sysctl's added
+ * (c) 1999 Manfred Spraul <manfreds@colorfullife.com>
+ * Enforced range limit on SEM_UNDO
+ * (c) 2001 Red Hat Inc <alan@redhat.com>
+ * Lockless wakeup
+ * (c) 2003 Manfred Spraul <manfred@colorfullife.com>
+ */
+
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/time.h>
+#include <linux/smp_lock.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+#include <asm/uaccess.h>
+#include "util.h"
+
+
+#define sem_lock(id)	((struct sem_array*)ipc_lock(&sem_ids,id))
+#define sem_unlock(sma)	ipc_unlock(&(sma)->sem_perm)
+#define sem_rmid(id)	((struct sem_array*)ipc_rmid(&sem_ids,id))
+#define sem_checkid(sma, semid)	\
+	ipc_checkid(&sem_ids,&sma->sem_perm,semid)
+#define sem_buildid(id, seq) \
+	ipc_buildid(&sem_ids, id, seq)
+static struct ipc_ids sem_ids;
+
+static int newary (key_t, int, int);
+static void freeary (struct sem_array *sma, int id);
+#ifdef CONFIG_PROC_FS
+static int sysvipc_sem_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data);
+#endif
+
+#define SEMMSL_FAST	256 /* 512 bytes on stack */
+#define SEMOPM_FAST	64  /* ~ 372 bytes on stack */
+
+/*
+ * linked list protection:
+ *	sem_undo.id_next,
+ *	sem_array.sem_pending{,last},
+ *	sem_array.sem_undo: sem_lock() for read/write
+ *	sem_undo.proc_next: only "current" is allowed to read/write that field.
+ *	
+ */
+
+int sem_ctls[4] = {SEMMSL, SEMMNS, SEMOPM, SEMMNI};
+#define sc_semmsl	(sem_ctls[0])
+#define sc_semmns	(sem_ctls[1])
+#define sc_semopm	(sem_ctls[2])
+#define sc_semmni	(sem_ctls[3])
+
+static int used_sems;
+
+void __init sem_init (void)
+{
+	used_sems = 0;
+	ipc_init_ids(&sem_ids,sc_semmni);
+
+#ifdef CONFIG_PROC_FS
+	create_proc_read_entry("sysvipc/sem", 0, NULL, sysvipc_sem_read_proc, NULL);
+#endif
+}
+
+/*
+ * Lockless wakeup algorithm:
+ * Without the check/retry algorithm a lockless wakeup is possible:
+ * - queue.status is initialized to -EINTR before blocking.
+ * - wakeup is performed by
+ *	* unlinking the queue entry from sma->sem_pending
+ *	* setting queue.status to IN_WAKEUP
+ *	  This is the notification for the blocked thread that a
+ *	  result value is imminent.
+ *	* call wake_up_process
+ *	* set queue.status to the final value.
+ * - the previously blocked thread checks queue.status:
+ *   	* if it's IN_WAKEUP, then it must wait until the value changes
+ *   	* if it's not -EINTR, then the operation was completed by
+ *   	  update_queue. semtimedop can return queue.status without
+ *   	  performing any operation on the semaphore array.
+ *   	* otherwise it must acquire the spinlock and check what's up.
+ *
+ * The two-stage algorithm is necessary to protect against the following
+ * races:
+ * - if queue.status is set after wake_up_process, then the woken up idle
+ *   thread could race forward and try (and fail) to acquire sma->lock
+ *   before update_queue had a chance to set queue.status
+ * - if queue.status is written before wake_up_process and if the
+ *   blocked process is woken up by a signal between writing
+ *   queue.status and the wake_up_process, then the woken up
+ *   process could return from semtimedop and die by calling
+ *   sys_exit before wake_up_process is called. Then wake_up_process
+ *   will oops, because the task structure is already invalid.
+ *   (yes, this happened on s390 with sysv msg).
+ *
+ */
+#define IN_WAKEUP	1
+
+static int newary (key_t key, int nsems, int semflg)
+{
+	int id;
+	int retval;
+	struct sem_array *sma;
+	int size;
+
+	if (!nsems)
+		return -EINVAL;
+	if (used_sems + nsems > sc_semmns)
+		return -ENOSPC;
+
+	size = sizeof (*sma) + nsems * sizeof (struct sem);
+	sma = ipc_rcu_alloc(size);
+	if (!sma) {
+		return -ENOMEM;
+	}
+	memset (sma, 0, size);
+
+	sma->sem_perm.mode = (semflg & S_IRWXUGO);
+	sma->sem_perm.key = key;
+
+	sma->sem_perm.security = NULL;
+	retval = security_sem_alloc(sma);
+	if (retval) {
+		ipc_rcu_putref(sma);
+		return retval;
+	}
+
+	id = ipc_addid(&sem_ids, &sma->sem_perm, sc_semmni);
+	if(id == -1) {
+		security_sem_free(sma);
+		ipc_rcu_putref(sma);
+		return -ENOSPC;
+	}
+	used_sems += nsems;
+
+	sma->sem_base = (struct sem *) &sma[1];
+	/* sma->sem_pending = NULL; */
+	sma->sem_pending_last = &sma->sem_pending;
+	/* sma->undo = NULL; */
+	sma->sem_nsems = nsems;
+	sma->sem_ctime = get_seconds();
+	sem_unlock(sma);
+
+	return sem_buildid(id, sma->sem_perm.seq);
+}
+
+asmlinkage long sys_semget (key_t key, int nsems, int semflg)
+{
+	int id, err = -EINVAL;
+	struct sem_array *sma;
+
+	if (nsems < 0 || nsems > sc_semmsl)
+		return -EINVAL;
+	down(&sem_ids.sem);
+	
+	if (key == IPC_PRIVATE) {
+		err = newary(key, nsems, semflg);
+	} else if ((id = ipc_findkey(&sem_ids, key)) == -1) {  /* key not used */
+		if (!(semflg & IPC_CREAT))
+			err = -ENOENT;
+		else
+			err = newary(key, nsems, semflg);
+	} else if (semflg & IPC_CREAT && semflg & IPC_EXCL) {
+		err = -EEXIST;
+	} else {
+		sma = sem_lock(id);
+		if(sma==NULL)
+			BUG();
+		if (nsems > sma->sem_nsems)
+			err = -EINVAL;
+		else if (ipcperms(&sma->sem_perm, semflg))
+			err = -EACCES;
+		else {
+			int semid = sem_buildid(id, sma->sem_perm.seq);
+			err = security_sem_associate(sma, semflg);
+			if (!err)
+				err = semid;
+		}
+		sem_unlock(sma);
+	}
+
+	up(&sem_ids.sem);
+	return err;
+}
+
+/* Manage the doubly linked list sma->sem_pending as a FIFO:
+ * insert new queue elements at the tail sma->sem_pending_last.
+ */
+static inline void append_to_queue (struct sem_array * sma,
+				    struct sem_queue * q)
+{
+	*(q->prev = sma->sem_pending_last) = q;
+	*(sma->sem_pending_last = &q->next) = NULL;
+}
+
+static inline void prepend_to_queue (struct sem_array * sma,
+				     struct sem_queue * q)
+{
+	q->next = sma->sem_pending;
+	*(q->prev = &sma->sem_pending) = q;
+	if (q->next)
+		q->next->prev = &q->next;
+	else /* sma->sem_pending_last == &sma->sem_pending */
+		sma->sem_pending_last = &q->next;
+}
+
+static inline void remove_from_queue (struct sem_array * sma,
+				      struct sem_queue * q)
+{
+	*(q->prev) = q->next;
+	if (q->next)
+		q->next->prev = q->prev;
+	else /* sma->sem_pending_last == &q->next */
+		sma->sem_pending_last = q->prev;
+	q->prev = NULL; /* mark as removed */
+}
+
+/*
+ * Determine whether a sequence of semaphore operations would succeed
+ * all at once. Return 0 if yes, 1 if need to sleep, else return error code.
+ */
+
+static int try_atomic_semop (struct sem_array * sma, struct sembuf * sops,
+			     int nsops, struct sem_undo *un, int pid)
+{
+	int result, sem_op;
+	struct sembuf *sop;
+	struct sem * curr;
+
+	for (sop = sops; sop < sops + nsops; sop++) {
+		curr = sma->sem_base + sop->sem_num;
+		sem_op = sop->sem_op;
+		result = curr->semval;
+  
+		if (!sem_op && result)
+			goto would_block;
+
+		result += sem_op;
+		if (result < 0)
+			goto would_block;
+		if (result > SEMVMX)
+			goto out_of_range;
+		if (sop->sem_flg & SEM_UNDO) {
+			int undo = un->semadj[sop->sem_num] - sem_op;
+			/*
+	 		 *	Exceeding the undo range is an error.
+			 */
+			if (undo < (-SEMAEM - 1) || undo > SEMAEM)
+				goto out_of_range;
+		}
+		curr->semval = result;
+	}
+
+	sop--;
+	while (sop >= sops) {
+		sma->sem_base[sop->sem_num].sempid = pid;
+		if (sop->sem_flg & SEM_UNDO)
+			un->semadj[sop->sem_num] -= sop->sem_op;
+		sop--;
+	}
+	
+	sma->sem_otime = get_seconds();
+	return 0;
+
+out_of_range:
+	result = -ERANGE;
+	goto undo;
+
+would_block:
+	if (sop->sem_flg & IPC_NOWAIT)
+		result = -EAGAIN;
+	else
+		result = 1;
+
+undo:
+	sop--;
+	while (sop >= sops) {
+		sma->sem_base[sop->sem_num].semval -= sop->sem_op;
+		sop--;
+	}
+
+	return result;
+}
+
+/* Go through the pending queue for the indicated semaphore
+ * looking for tasks that can be completed.
+ */
+static void update_queue (struct sem_array * sma)
+{
+	int error;
+	struct sem_queue * q;
+
+	q = sma->sem_pending;
+	while(q) {
+		error = try_atomic_semop(sma, q->sops, q->nsops,
+					 q->undo, q->pid);
+
+		/* Does q->sleeper still need to sleep? */
+		if (error <= 0) {
+			struct sem_queue *n;
+			remove_from_queue(sma,q);
+			q->status = IN_WAKEUP;
+			/*
+			 * Continue scanning. The next operation
+			 * that must be checked depends on the type of the
+			 * completed operation:
+			 * - if the operation modified the array, then
+			 *   restart from the head of the queue and
+			 *   check for threads that might be waiting
+			 *   for semaphore values to become 0.
+			 * - if the operation didn't modify the array,
+			 *   then just continue.
+			 */
+			if (q->alter)
+				n = sma->sem_pending;
+			else
+				n = q->next;
+			wake_up_process(q->sleeper);
+			/* hands-off: q will disappear immediately after
+			 * writing q->status.
+			 */
+			q->status = error;
+			q = n;
+		} else {
+			q = q->next;
+		}
+	}
+}
+
+/* The following counts are associated to each semaphore:
+ *   semncnt        number of tasks waiting on semval being nonzero
+ *   semzcnt        number of tasks waiting on semval being zero
+ * This model assumes that a task waits on exactly one semaphore.
+ * Since semaphore operations are to be performed atomically, tasks actually
+ * wait on a whole sequence of semaphores simultaneously.
+ * The counts we return here are a rough approximation, but still
+ * warrant that semncnt+semzcnt>0 if the task is on the pending queue.
+ */
+static int count_semncnt (struct sem_array * sma, ushort semnum)
+{
+	int semncnt;
+	struct sem_queue * q;
+
+	semncnt = 0;
+	for (q = sma->sem_pending; q; q = q->next) {
+		struct sembuf * sops = q->sops;
+		int nsops = q->nsops;
+		int i;
+		for (i = 0; i < nsops; i++)
+			if (sops[i].sem_num == semnum
+			    && (sops[i].sem_op < 0)
+			    && !(sops[i].sem_flg & IPC_NOWAIT))
+				semncnt++;
+	}
+	return semncnt;
+}
+static int count_semzcnt (struct sem_array * sma, ushort semnum)
+{
+	int semzcnt;
+	struct sem_queue * q;
+
+	semzcnt = 0;
+	for (q = sma->sem_pending; q; q = q->next) {
+		struct sembuf * sops = q->sops;
+		int nsops = q->nsops;
+		int i;
+		for (i = 0; i < nsops; i++)
+			if (sops[i].sem_num == semnum
+			    && (sops[i].sem_op == 0)
+			    && !(sops[i].sem_flg & IPC_NOWAIT))
+				semzcnt++;
+	}
+	return semzcnt;
+}
+
+/* Free a semaphore set. freeary() is called with sem_ids.sem down and
+ * the spinlock for this semaphore set hold. sem_ids.sem remains locked
+ * on exit.
+ */
+static void freeary (struct sem_array *sma, int id)
+{
+	struct sem_undo *un;
+	struct sem_queue *q;
+	int size;
+
+	/* Invalidate the existing undo structures for this semaphore set.
+	 * (They will be freed without any further action in exit_sem()
+	 * or during the next semop.)
+	 */
+	for (un = sma->undo; un; un = un->id_next)
+		un->semid = -1;
+
+	/* Wake up all pending processes and let them fail with EIDRM. */
+	q = sma->sem_pending;
+	while(q) {
+		struct sem_queue *n;
+		/* lazy remove_from_queue: we are killing the whole queue */
+		q->prev = NULL;
+		n = q->next;
+		q->status = IN_WAKEUP;
+		wake_up_process(q->sleeper); /* doesn't sleep */
+		q->status = -EIDRM;	/* hands-off q */
+		q = n;
+	}
+
+	/* Remove the semaphore set from the ID array*/
+	sma = sem_rmid(id);
+	sem_unlock(sma);
+
+	used_sems -= sma->sem_nsems;
+	size = sizeof (*sma) + sma->sem_nsems * sizeof (struct sem);
+	security_sem_free(sma);
+	ipc_rcu_putref(sma);
+}
+
+static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version)
+{
+	switch(version) {
+	case IPC_64:
+		return copy_to_user(buf, in, sizeof(*in));
+	case IPC_OLD:
+	    {
+		struct semid_ds out;
+
+		ipc64_perm_to_ipc_perm(&in->sem_perm, &out.sem_perm);
+
+		out.sem_otime	= in->sem_otime;
+		out.sem_ctime	= in->sem_ctime;
+		out.sem_nsems	= in->sem_nsems;
+
+		return copy_to_user(buf, &out, sizeof(out));
+	    }
+	default:
+		return -EINVAL;
+	}
+}
+
+static int semctl_nolock(int semid, int semnum, int cmd, int version, union semun arg)
+{
+	int err = -EINVAL;
+	struct sem_array *sma;
+
+	switch(cmd) {
+	case IPC_INFO:
+	case SEM_INFO:
+	{
+		struct seminfo seminfo;
+		int max_id;
+
+		err = security_sem_semctl(NULL, cmd);
+		if (err)
+			return err;
+		
+		memset(&seminfo,0,sizeof(seminfo));
+		seminfo.semmni = sc_semmni;
+		seminfo.semmns = sc_semmns;
+		seminfo.semmsl = sc_semmsl;
+		seminfo.semopm = sc_semopm;
+		seminfo.semvmx = SEMVMX;
+		seminfo.semmnu = SEMMNU;
+		seminfo.semmap = SEMMAP;
+		seminfo.semume = SEMUME;
+		down(&sem_ids.sem);
+		if (cmd == SEM_INFO) {
+			seminfo.semusz = sem_ids.in_use;
+			seminfo.semaem = used_sems;
+		} else {
+			seminfo.semusz = SEMUSZ;
+			seminfo.semaem = SEMAEM;
+		}
+		max_id = sem_ids.max_id;
+		up(&sem_ids.sem);
+		if (copy_to_user (arg.__buf, &seminfo, sizeof(struct seminfo))) 
+			return -EFAULT;
+		return (max_id < 0) ? 0: max_id;
+	}
+	case SEM_STAT:
+	{
+		struct semid64_ds tbuf;
+		int id;
+
+		if(semid >= sem_ids.entries->size)
+			return -EINVAL;
+
+		memset(&tbuf,0,sizeof(tbuf));
+
+		sma = sem_lock(semid);
+		if(sma == NULL)
+			return -EINVAL;
+
+		err = -EACCES;
+		if (ipcperms (&sma->sem_perm, S_IRUGO))
+			goto out_unlock;
+
+		err = security_sem_semctl(sma, cmd);
+		if (err)
+			goto out_unlock;
+
+		id = sem_buildid(semid, sma->sem_perm.seq);
+
+		kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
+		tbuf.sem_otime  = sma->sem_otime;
+		tbuf.sem_ctime  = sma->sem_ctime;
+		tbuf.sem_nsems  = sma->sem_nsems;
+		sem_unlock(sma);
+		if (copy_semid_to_user (arg.buf, &tbuf, version))
+			return -EFAULT;
+		return id;
+	}
+	default:
+		return -EINVAL;
+	}
+	return err;
+out_unlock:
+	sem_unlock(sma);
+	return err;
+}
+
+static int semctl_main(int semid, int semnum, int cmd, int version, union semun arg)
+{
+	struct sem_array *sma;
+	struct sem* curr;
+	int err;
+	ushort fast_sem_io[SEMMSL_FAST];
+	ushort* sem_io = fast_sem_io;
+	int nsems;
+
+	sma = sem_lock(semid);
+	if(sma==NULL)
+		return -EINVAL;
+
+	nsems = sma->sem_nsems;
+
+	err=-EIDRM;
+	if (sem_checkid(sma,semid))
+		goto out_unlock;
+
+	err = -EACCES;
+	if (ipcperms (&sma->sem_perm, (cmd==SETVAL||cmd==SETALL)?S_IWUGO:S_IRUGO))
+		goto out_unlock;
+
+	err = security_sem_semctl(sma, cmd);
+	if (err)
+		goto out_unlock;
+
+	err = -EACCES;
+	switch (cmd) {
+	case GETALL:
+	{
+		ushort __user *array = arg.array;
+		int i;
+
+		if(nsems > SEMMSL_FAST) {
+			ipc_rcu_getref(sma);
+			sem_unlock(sma);			
+
+			sem_io = ipc_alloc(sizeof(ushort)*nsems);
+			if(sem_io == NULL) {
+				ipc_lock_by_ptr(&sma->sem_perm);
+				ipc_rcu_putref(sma);
+				sem_unlock(sma);
+				return -ENOMEM;
+			}
+
+			ipc_lock_by_ptr(&sma->sem_perm);
+			ipc_rcu_putref(sma);
+			if (sma->sem_perm.deleted) {
+				sem_unlock(sma);
+				err = -EIDRM;
+				goto out_free;
+			}
+		}
+
+		for (i = 0; i < sma->sem_nsems; i++)
+			sem_io[i] = sma->sem_base[i].semval;
+		sem_unlock(sma);
+		err = 0;
+		if(copy_to_user(array, sem_io, nsems*sizeof(ushort)))
+			err = -EFAULT;
+		goto out_free;
+	}
+	case SETALL:
+	{
+		int i;
+		struct sem_undo *un;
+
+		ipc_rcu_getref(sma);
+		sem_unlock(sma);
+
+		if(nsems > SEMMSL_FAST) {
+			sem_io = ipc_alloc(sizeof(ushort)*nsems);
+			if(sem_io == NULL) {
+				ipc_lock_by_ptr(&sma->sem_perm);
+				ipc_rcu_putref(sma);
+				sem_unlock(sma);
+				return -ENOMEM;
+			}
+		}
+
+		if (copy_from_user (sem_io, arg.array, nsems*sizeof(ushort))) {
+			ipc_lock_by_ptr(&sma->sem_perm);
+			ipc_rcu_putref(sma);
+			sem_unlock(sma);
+			err = -EFAULT;
+			goto out_free;
+		}
+
+		for (i = 0; i < nsems; i++) {
+			if (sem_io[i] > SEMVMX) {
+				ipc_lock_by_ptr(&sma->sem_perm);
+				ipc_rcu_putref(sma);
+				sem_unlock(sma);
+				err = -ERANGE;
+				goto out_free;
+			}
+		}
+		ipc_lock_by_ptr(&sma->sem_perm);
+		ipc_rcu_putref(sma);
+		if (sma->sem_perm.deleted) {
+			sem_unlock(sma);
+			err = -EIDRM;
+			goto out_free;
+		}
+
+		for (i = 0; i < nsems; i++)
+			sma->sem_base[i].semval = sem_io[i];
+		for (un = sma->undo; un; un = un->id_next)
+			for (i = 0; i < nsems; i++)
+				un->semadj[i] = 0;
+		sma->sem_ctime = get_seconds();
+		/* maybe some queued-up processes were waiting for this */
+		update_queue(sma);
+		err = 0;
+		goto out_unlock;
+	}
+	case IPC_STAT:
+	{
+		struct semid64_ds tbuf;
+		memset(&tbuf,0,sizeof(tbuf));
+		kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
+		tbuf.sem_otime  = sma->sem_otime;
+		tbuf.sem_ctime  = sma->sem_ctime;
+		tbuf.sem_nsems  = sma->sem_nsems;
+		sem_unlock(sma);
+		if (copy_semid_to_user (arg.buf, &tbuf, version))
+			return -EFAULT;
+		return 0;
+	}
+	/* GETVAL, GETPID, GETNCTN, GETZCNT, SETVAL: fall-through */
+	}
+	err = -EINVAL;
+	if(semnum < 0 || semnum >= nsems)
+		goto out_unlock;
+
+	curr = &sma->sem_base[semnum];
+
+	switch (cmd) {
+	case GETVAL:
+		err = curr->semval;
+		goto out_unlock;
+	case GETPID:
+		err = curr->sempid;
+		goto out_unlock;
+	case GETNCNT:
+		err = count_semncnt(sma,semnum);
+		goto out_unlock;
+	case GETZCNT:
+		err = count_semzcnt(sma,semnum);
+		goto out_unlock;
+	case SETVAL:
+	{
+		int val = arg.val;
+		struct sem_undo *un;
+		err = -ERANGE;
+		if (val > SEMVMX || val < 0)
+			goto out_unlock;
+
+		for (un = sma->undo; un; un = un->id_next)
+			un->semadj[semnum] = 0;
+		curr->semval = val;
+		curr->sempid = current->tgid;
+		sma->sem_ctime = get_seconds();
+		/* maybe some queued-up processes were waiting for this */
+		update_queue(sma);
+		err = 0;
+		goto out_unlock;
+	}
+	}
+out_unlock:
+	sem_unlock(sma);
+out_free:
+	if(sem_io != fast_sem_io)
+		ipc_free(sem_io, sizeof(ushort)*nsems);
+	return err;
+}
+
+struct sem_setbuf {
+	uid_t	uid;
+	gid_t	gid;
+	mode_t	mode;
+};
+
+static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __user *buf, int version)
+{
+	switch(version) {
+	case IPC_64:
+	    {
+		struct semid64_ds tbuf;
+
+		if(copy_from_user(&tbuf, buf, sizeof(tbuf)))
+			return -EFAULT;
+
+		out->uid	= tbuf.sem_perm.uid;
+		out->gid	= tbuf.sem_perm.gid;
+		out->mode	= tbuf.sem_perm.mode;
+
+		return 0;
+	    }
+	case IPC_OLD:
+	    {
+		struct semid_ds tbuf_old;
+
+		if(copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
+			return -EFAULT;
+
+		out->uid	= tbuf_old.sem_perm.uid;
+		out->gid	= tbuf_old.sem_perm.gid;
+		out->mode	= tbuf_old.sem_perm.mode;
+
+		return 0;
+	    }
+	default:
+		return -EINVAL;
+	}
+}
+
+static int semctl_down(int semid, int semnum, int cmd, int version, union semun arg)
+{
+	struct sem_array *sma;
+	int err;
+	struct sem_setbuf setbuf;
+	struct kern_ipc_perm *ipcp;
+
+	if(cmd == IPC_SET) {
+		if(copy_semid_from_user (&setbuf, arg.buf, version))
+			return -EFAULT;
+		if ((err = audit_ipc_perms(0, setbuf.uid, setbuf.gid, setbuf.mode)))
+			return err;
+	}
+	sma = sem_lock(semid);
+	if(sma==NULL)
+		return -EINVAL;
+
+	if (sem_checkid(sma,semid)) {
+		err=-EIDRM;
+		goto out_unlock;
+	}	
+	ipcp = &sma->sem_perm;
+	
+	if (current->euid != ipcp->cuid && 
+	    current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) {
+	    	err=-EPERM;
+		goto out_unlock;
+	}
+
+	err = security_sem_semctl(sma, cmd);
+	if (err)
+		goto out_unlock;
+
+	switch(cmd){
+	case IPC_RMID:
+		freeary(sma, semid);
+		err = 0;
+		break;
+	case IPC_SET:
+		ipcp->uid = setbuf.uid;
+		ipcp->gid = setbuf.gid;
+		ipcp->mode = (ipcp->mode & ~S_IRWXUGO)
+				| (setbuf.mode & S_IRWXUGO);
+		sma->sem_ctime = get_seconds();
+		sem_unlock(sma);
+		err = 0;
+		break;
+	default:
+		sem_unlock(sma);
+		err = -EINVAL;
+		break;
+	}
+	return err;
+
+out_unlock:
+	sem_unlock(sma);
+	return err;
+}
+
+asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg)
+{
+	int err = -EINVAL;
+	int version;
+
+	if (semid < 0)
+		return -EINVAL;
+
+	version = ipc_parse_version(&cmd);
+
+	switch(cmd) {
+	case IPC_INFO:
+	case SEM_INFO:
+	case SEM_STAT:
+		err = semctl_nolock(semid,semnum,cmd,version,arg);
+		return err;
+	case GETALL:
+	case GETVAL:
+	case GETPID:
+	case GETNCNT:
+	case GETZCNT:
+	case IPC_STAT:
+	case SETVAL:
+	case SETALL:
+		err = semctl_main(semid,semnum,cmd,version,arg);
+		return err;
+	case IPC_RMID:
+	case IPC_SET:
+		down(&sem_ids.sem);
+		err = semctl_down(semid,semnum,cmd,version,arg);
+		up(&sem_ids.sem);
+		return err;
+	default:
+		return -EINVAL;
+	}
+}
+
+static inline void lock_semundo(void)
+{
+	struct sem_undo_list *undo_list;
+
+	undo_list = current->sysvsem.undo_list;
+	if ((undo_list != NULL) && (atomic_read(&undo_list->refcnt) != 1))
+		spin_lock(&undo_list->lock);
+}
+
+/* This code has an interaction with copy_semundo().
+ * Consider; two tasks are sharing the undo_list. task1
+ * acquires the undo_list lock in lock_semundo().  If task2 now
+ * exits before task1 releases the lock (by calling
+ * unlock_semundo()), then task1 will never call spin_unlock().
+ * This leave the sem_undo_list in a locked state.  If task1 now creats task3
+ * and once again shares the sem_undo_list, the sem_undo_list will still be
+ * locked, and future SEM_UNDO operations will deadlock.  This case is
+ * dealt with in copy_semundo() by having it reinitialize the spin lock when 
+ * the refcnt goes from 1 to 2.
+ */
+static inline void unlock_semundo(void)
+{
+	struct sem_undo_list *undo_list;
+
+	undo_list = current->sysvsem.undo_list;
+	if ((undo_list != NULL) && (atomic_read(&undo_list->refcnt) != 1))
+		spin_unlock(&undo_list->lock);
+}
+
+
+/* If the task doesn't already have a undo_list, then allocate one
+ * here.  We guarantee there is only one thread using this undo list,
+ * and current is THE ONE
+ *
+ * If this allocation and assignment succeeds, but later
+ * portions of this code fail, there is no need to free the sem_undo_list.
+ * Just let it stay associated with the task, and it'll be freed later
+ * at exit time.
+ *
+ * This can block, so callers must hold no locks.
+ */
+static inline int get_undo_list(struct sem_undo_list **undo_listp)
+{
+	struct sem_undo_list *undo_list;
+	int size;
+
+	undo_list = current->sysvsem.undo_list;
+	if (!undo_list) {
+		size = sizeof(struct sem_undo_list);
+		undo_list = (struct sem_undo_list *) kmalloc(size, GFP_KERNEL);
+		if (undo_list == NULL)
+			return -ENOMEM;
+		memset(undo_list, 0, size);
+		/* don't initialize unodhd->lock here.  It's done
+		 * in copy_semundo() instead.
+		 */
+		atomic_set(&undo_list->refcnt, 1);
+		current->sysvsem.undo_list = undo_list;
+	}
+	*undo_listp = undo_list;
+	return 0;
+}
+
+static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
+{
+	struct sem_undo **last, *un;
+
+	last = &ulp->proc_list;
+	un = *last;
+	while(un != NULL) {
+		if(un->semid==semid)
+			break;
+		if(un->semid==-1) {
+			*last=un->proc_next;
+			kfree(un);
+		} else {
+			last=&un->proc_next;
+		}
+		un=*last;
+	}
+	return un;
+}
+
+static struct sem_undo *find_undo(int semid)
+{
+	struct sem_array *sma;
+	struct sem_undo_list *ulp;
+	struct sem_undo *un, *new;
+	int nsems;
+	int error;
+
+	error = get_undo_list(&ulp);
+	if (error)
+		return ERR_PTR(error);
+
+	lock_semundo();
+	un = lookup_undo(ulp, semid);
+	unlock_semundo();
+	if (likely(un!=NULL))
+		goto out;
+
+	/* no undo structure around - allocate one. */
+	sma = sem_lock(semid);
+	un = ERR_PTR(-EINVAL);
+	if(sma==NULL)
+		goto out;
+	un = ERR_PTR(-EIDRM);
+	if (sem_checkid(sma,semid)) {
+		sem_unlock(sma);
+		goto out;
+	}
+	nsems = sma->sem_nsems;
+	ipc_rcu_getref(sma);
+	sem_unlock(sma);
+
+	new = (struct sem_undo *) kmalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL);
+	if (!new) {
+		ipc_lock_by_ptr(&sma->sem_perm);
+		ipc_rcu_putref(sma);
+		sem_unlock(sma);
+		return ERR_PTR(-ENOMEM);
+	}
+	memset(new, 0, sizeof(struct sem_undo) + sizeof(short)*nsems);
+	new->semadj = (short *) &new[1];
+	new->semid = semid;
+
+	lock_semundo();
+	un = lookup_undo(ulp, semid);
+	if (un) {
+		unlock_semundo();
+		kfree(new);
+		ipc_lock_by_ptr(&sma->sem_perm);
+		ipc_rcu_putref(sma);
+		sem_unlock(sma);
+		goto out;
+	}
+	ipc_lock_by_ptr(&sma->sem_perm);
+	ipc_rcu_putref(sma);
+	if (sma->sem_perm.deleted) {
+		sem_unlock(sma);
+		unlock_semundo();
+		kfree(new);
+		un = ERR_PTR(-EIDRM);
+		goto out;
+	}
+	new->proc_next = ulp->proc_list;
+	ulp->proc_list = new;
+	new->id_next = sma->undo;
+	sma->undo = new;
+	sem_unlock(sma);
+	un = new;
+	unlock_semundo();
+out:
+	return un;
+}
+
+asmlinkage long sys_semtimedop(int semid, struct sembuf __user *tsops,
+			unsigned nsops, const struct timespec __user *timeout)
+{
+	int error = -EINVAL;
+	struct sem_array *sma;
+	struct sembuf fast_sops[SEMOPM_FAST];
+	struct sembuf* sops = fast_sops, *sop;
+	struct sem_undo *un;
+	int undos = 0, decrease = 0, alter = 0, max;
+	struct sem_queue queue;
+	unsigned long jiffies_left = 0;
+
+	if (nsops < 1 || semid < 0)
+		return -EINVAL;
+	if (nsops > sc_semopm)
+		return -E2BIG;
+	if(nsops > SEMOPM_FAST) {
+		sops = kmalloc(sizeof(*sops)*nsops,GFP_KERNEL);
+		if(sops==NULL)
+			return -ENOMEM;
+	}
+	if (copy_from_user (sops, tsops, nsops * sizeof(*tsops))) {
+		error=-EFAULT;
+		goto out_free;
+	}
+	if (timeout) {
+		struct timespec _timeout;
+		if (copy_from_user(&_timeout, timeout, sizeof(*timeout))) {
+			error = -EFAULT;
+			goto out_free;
+		}
+		if (_timeout.tv_sec < 0 || _timeout.tv_nsec < 0 ||
+			_timeout.tv_nsec >= 1000000000L) {
+			error = -EINVAL;
+			goto out_free;
+		}
+		jiffies_left = timespec_to_jiffies(&_timeout);
+	}
+	max = 0;
+	for (sop = sops; sop < sops + nsops; sop++) {
+		if (sop->sem_num >= max)
+			max = sop->sem_num;
+		if (sop->sem_flg & SEM_UNDO)
+			undos++;
+		if (sop->sem_op < 0)
+			decrease = 1;
+		if (sop->sem_op > 0)
+			alter = 1;
+	}
+	alter |= decrease;
+
+retry_undos:
+	if (undos) {
+		un = find_undo(semid);
+		if (IS_ERR(un)) {
+			error = PTR_ERR(un);
+			goto out_free;
+		}
+	} else
+		un = NULL;
+
+	sma = sem_lock(semid);
+	error=-EINVAL;
+	if(sma==NULL)
+		goto out_free;
+	error = -EIDRM;
+	if (sem_checkid(sma,semid))
+		goto out_unlock_free;
+	/*
+	 * semid identifies are not unique - find_undo may have
+	 * allocated an undo structure, it was invalidated by an RMID
+	 * and now a new array with received the same id. Check and retry.
+	 */
+	if (un && un->semid == -1) {
+		sem_unlock(sma);
+		goto retry_undos;
+	}
+	error = -EFBIG;
+	if (max >= sma->sem_nsems)
+		goto out_unlock_free;
+
+	error = -EACCES;
+	if (ipcperms(&sma->sem_perm, alter ? S_IWUGO : S_IRUGO))
+		goto out_unlock_free;
+
+	error = security_sem_semop(sma, sops, nsops, alter);
+	if (error)
+		goto out_unlock_free;
+
+	error = try_atomic_semop (sma, sops, nsops, un, current->tgid);
+	if (error <= 0) {
+		if (alter && error == 0)
+			update_queue (sma);
+		goto out_unlock_free;
+	}
+
+	/* We need to sleep on this operation, so we put the current
+	 * task into the pending queue and go to sleep.
+	 */
+		
+	queue.sma = sma;
+	queue.sops = sops;
+	queue.nsops = nsops;
+	queue.undo = un;
+	queue.pid = current->tgid;
+	queue.id = semid;
+	queue.alter = alter;
+	if (alter)
+		append_to_queue(sma ,&queue);
+	else
+		prepend_to_queue(sma ,&queue);
+
+	queue.status = -EINTR;
+	queue.sleeper = current;
+	current->state = TASK_INTERRUPTIBLE;
+	sem_unlock(sma);
+
+	if (timeout)
+		jiffies_left = schedule_timeout(jiffies_left);
+	else
+		schedule();
+
+	error = queue.status;
+	while(unlikely(error == IN_WAKEUP)) {
+		cpu_relax();
+		error = queue.status;
+	}
+
+	if (error != -EINTR) {
+		/* fast path: update_queue already obtained all requested
+		 * resources */
+		goto out_free;
+	}
+
+	sma = sem_lock(semid);
+	if(sma==NULL) {
+		if(queue.prev != NULL)
+			BUG();
+		error = -EIDRM;
+		goto out_free;
+	}
+
+	/*
+	 * If queue.status != -EINTR we are woken up by another process
+	 */
+	error = queue.status;
+	if (error != -EINTR) {
+		goto out_unlock_free;
+	}
+
+	/*
+	 * If an interrupt occurred we have to clean up the queue
+	 */
+	if (timeout && jiffies_left == 0)
+		error = -EAGAIN;
+	remove_from_queue(sma,&queue);
+	goto out_unlock_free;
+
+out_unlock_free:
+	sem_unlock(sma);
+out_free:
+	if(sops != fast_sops)
+		kfree(sops);
+	return error;
+}
+
+asmlinkage long sys_semop (int semid, struct sembuf __user *tsops, unsigned nsops)
+{
+	return sys_semtimedop(semid, tsops, nsops, NULL);
+}
+
+/* If CLONE_SYSVSEM is set, establish sharing of SEM_UNDO state between
+ * parent and child tasks.
+ *
+ * See the notes above unlock_semundo() regarding the spin_lock_init()
+ * in this code.  Initialize the undo_list->lock here instead of get_undo_list()
+ * because of the reasoning in the comment above unlock_semundo.
+ */
+
+int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
+{
+	struct sem_undo_list *undo_list;
+	int error;
+
+	if (clone_flags & CLONE_SYSVSEM) {
+		error = get_undo_list(&undo_list);
+		if (error)
+			return error;
+		if (atomic_read(&undo_list->refcnt) == 1)
+			spin_lock_init(&undo_list->lock);
+		atomic_inc(&undo_list->refcnt);
+		tsk->sysvsem.undo_list = undo_list;
+	} else 
+		tsk->sysvsem.undo_list = NULL;
+
+	return 0;
+}
+
+/*
+ * add semadj values to semaphores, free undo structures.
+ * undo structures are not freed when semaphore arrays are destroyed
+ * so some of them may be out of date.
+ * IMPLEMENTATION NOTE: There is some confusion over whether the
+ * set of adjustments that needs to be done should be done in an atomic
+ * manner or not. That is, if we are attempting to decrement the semval
+ * should we queue up and wait until we can do so legally?
+ * The original implementation attempted to do this (queue and wait).
+ * The current implementation does not do so. The POSIX standard
+ * and SVID should be consulted to determine what behavior is mandated.
+ */
+void exit_sem(struct task_struct *tsk)
+{
+	struct sem_undo_list *undo_list;
+	struct sem_undo *u, **up;
+
+	undo_list = tsk->sysvsem.undo_list;
+	if (!undo_list)
+		return;
+
+	if (!atomic_dec_and_test(&undo_list->refcnt))
+		return;
+
+	/* There's no need to hold the semundo list lock, as current
+         * is the last task exiting for this undo list.
+	 */
+	for (up = &undo_list->proc_list; (u = *up); *up = u->proc_next, kfree(u)) {
+		struct sem_array *sma;
+		int nsems, i;
+		struct sem_undo *un, **unp;
+		int semid;
+	       
+		semid = u->semid;
+
+		if(semid == -1)
+			continue;
+		sma = sem_lock(semid);
+		if (sma == NULL)
+			continue;
+
+		if (u->semid == -1)
+			goto next_entry;
+
+		BUG_ON(sem_checkid(sma,u->semid));
+
+		/* remove u from the sma->undo list */
+		for (unp = &sma->undo; (un = *unp); unp = &un->id_next) {
+			if (u == un)
+				goto found;
+		}
+		printk ("exit_sem undo list error id=%d\n", u->semid);
+		goto next_entry;
+found:
+		*unp = un->id_next;
+		/* perform adjustments registered in u */
+		nsems = sma->sem_nsems;
+		for (i = 0; i < nsems; i++) {
+			struct sem * sem = &sma->sem_base[i];
+			if (u->semadj[i]) {
+				sem->semval += u->semadj[i];
+				/*
+				 * Range checks of the new semaphore value,
+				 * not defined by sus:
+				 * - Some unices ignore the undo entirely
+				 *   (e.g. HP UX 11i 11.22, Tru64 V5.1)
+				 * - some cap the value (e.g. FreeBSD caps
+				 *   at 0, but doesn't enforce SEMVMX)
+				 *
+				 * Linux caps the semaphore value, both at 0
+				 * and at SEMVMX.
+				 *
+				 * 	Manfred <manfred@colorfullife.com>
+				 */
+				if (sem->semval < 0)
+					sem->semval = 0;
+				if (sem->semval > SEMVMX)
+					sem->semval = SEMVMX;
+				sem->sempid = current->tgid;
+			}
+		}
+		sma->sem_otime = get_seconds();
+		/* maybe some queued-up processes were waiting for this */
+		update_queue(sma);
+next_entry:
+		sem_unlock(sma);
+	}
+	kfree(undo_list);
+}
+
+#ifdef CONFIG_PROC_FS
+static int sysvipc_sem_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
+{
+	off_t pos = 0;
+	off_t begin = 0;
+	int i, len = 0;
+
+	len += sprintf(buffer, "       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n");
+	down(&sem_ids.sem);
+
+	for(i = 0; i <= sem_ids.max_id; i++) {
+		struct sem_array *sma;
+		sma = sem_lock(i);
+		if(sma) {
+			len += sprintf(buffer + len, "%10d %10d  %4o %10lu %5u %5u %5u %5u %10lu %10lu\n",
+				sma->sem_perm.key,
+				sem_buildid(i,sma->sem_perm.seq),
+				sma->sem_perm.mode,
+				sma->sem_nsems,
+				sma->sem_perm.uid,
+				sma->sem_perm.gid,
+				sma->sem_perm.cuid,
+				sma->sem_perm.cgid,
+				sma->sem_otime,
+				sma->sem_ctime);
+			sem_unlock(sma);
+
+			pos += len;
+			if(pos < offset) {
+				len = 0;
+	    			begin = pos;
+			}
+			if(pos > offset + length)
+				goto done;
+		}
+	}
+	*eof = 1;
+done:
+	up(&sem_ids.sem);
+	*start = buffer + (offset - begin);
+	len -= (offset - begin);
+	if(len > length)
+		len = length;
+	if(len < 0)
+		len = 0;
+	return len;
+}
+#endif
diff --git a/ipc/shm.c b/ipc/shm.c
new file mode 100644
index 0000000..06cd5c91
--- /dev/null
+++ b/ipc/shm.c
@@ -0,0 +1,917 @@
+/*
+ * linux/ipc/shm.c
+ * Copyright (C) 1992, 1993 Krishna Balasubramanian
+ *	 Many improvements/fixes by Bruno Haible.
+ * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994.
+ * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli.
+ *
+ * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
+ * BIGMEM support, Andrea Arcangeli <andrea@suse.de>
+ * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr>
+ * HIGHMEM support, Ingo Molnar <mingo@redhat.com>
+ * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com>
+ * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com>
+ * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com>
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/shm.h>
+#include <linux/init.h>
+#include <linux/file.h>
+#include <linux/mman.h>
+#include <linux/proc_fs.h>
+#include <linux/shmem_fs.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+#include <asm/uaccess.h>
+
+#include "util.h"
+
+#define shm_flags	shm_perm.mode
+
+static struct file_operations shm_file_operations;
+static struct vm_operations_struct shm_vm_ops;
+
+static struct ipc_ids shm_ids;
+
+#define shm_lock(id)	((struct shmid_kernel*)ipc_lock(&shm_ids,id))
+#define shm_unlock(shp)	ipc_unlock(&(shp)->shm_perm)
+#define shm_get(id)	((struct shmid_kernel*)ipc_get(&shm_ids,id))
+#define shm_buildid(id, seq) \
+	ipc_buildid(&shm_ids, id, seq)
+
+static int newseg (key_t key, int shmflg, size_t size);
+static void shm_open (struct vm_area_struct *shmd);
+static void shm_close (struct vm_area_struct *shmd);
+#ifdef CONFIG_PROC_FS
+static int sysvipc_shm_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data);
+#endif
+
+size_t	shm_ctlmax = SHMMAX;
+size_t 	shm_ctlall = SHMALL;
+int 	shm_ctlmni = SHMMNI;
+
+static int shm_tot; /* total number of shared memory pages */
+
+void __init shm_init (void)
+{
+	ipc_init_ids(&shm_ids, 1);
+#ifdef CONFIG_PROC_FS
+	create_proc_read_entry("sysvipc/shm", 0, NULL, sysvipc_shm_read_proc, NULL);
+#endif
+}
+
+static inline int shm_checkid(struct shmid_kernel *s, int id)
+{
+	if (ipc_checkid(&shm_ids,&s->shm_perm,id))
+		return -EIDRM;
+	return 0;
+}
+
+static inline struct shmid_kernel *shm_rmid(int id)
+{
+	return (struct shmid_kernel *)ipc_rmid(&shm_ids,id);
+}
+
+static inline int shm_addid(struct shmid_kernel *shp)
+{
+	return ipc_addid(&shm_ids, &shp->shm_perm, shm_ctlmni);
+}
+
+
+
+static inline void shm_inc (int id) {
+	struct shmid_kernel *shp;
+
+	if(!(shp = shm_lock(id)))
+		BUG();
+	shp->shm_atim = get_seconds();
+	shp->shm_lprid = current->tgid;
+	shp->shm_nattch++;
+	shm_unlock(shp);
+}
+
+/* This is called by fork, once for every shm attach. */
+static void shm_open (struct vm_area_struct *shmd)
+{
+	shm_inc (shmd->vm_file->f_dentry->d_inode->i_ino);
+}
+
+/*
+ * shm_destroy - free the struct shmid_kernel
+ *
+ * @shp: struct to free
+ *
+ * It has to be called with shp and shm_ids.sem locked,
+ * but returns with shp unlocked and freed.
+ */
+static void shm_destroy (struct shmid_kernel *shp)
+{
+	shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	shm_rmid (shp->id);
+	shm_unlock(shp);
+	if (!is_file_hugepages(shp->shm_file))
+		shmem_lock(shp->shm_file, 0, shp->mlock_user);
+	else
+		user_shm_unlock(shp->shm_file->f_dentry->d_inode->i_size,
+						shp->mlock_user);
+	fput (shp->shm_file);
+	security_shm_free(shp);
+	ipc_rcu_putref(shp);
+}
+
+/*
+ * remove the attach descriptor shmd.
+ * free memory for segment if it is marked destroyed.
+ * The descriptor has already been removed from the current->mm->mmap list
+ * and will later be kfree()d.
+ */
+static void shm_close (struct vm_area_struct *shmd)
+{
+	struct file * file = shmd->vm_file;
+	int id = file->f_dentry->d_inode->i_ino;
+	struct shmid_kernel *shp;
+
+	down (&shm_ids.sem);
+	/* remove from the list of attaches of the shm segment */
+	if(!(shp = shm_lock(id)))
+		BUG();
+	shp->shm_lprid = current->tgid;
+	shp->shm_dtim = get_seconds();
+	shp->shm_nattch--;
+	if(shp->shm_nattch == 0 &&
+	   shp->shm_flags & SHM_DEST)
+		shm_destroy (shp);
+	else
+		shm_unlock(shp);
+	up (&shm_ids.sem);
+}
+
+static int shm_mmap(struct file * file, struct vm_area_struct * vma)
+{
+	file_accessed(file);
+	vma->vm_ops = &shm_vm_ops;
+	shm_inc(file->f_dentry->d_inode->i_ino);
+	return 0;
+}
+
+static struct file_operations shm_file_operations = {
+	.mmap	= shm_mmap
+};
+
+static struct vm_operations_struct shm_vm_ops = {
+	.open	= shm_open,	/* callback for a new vm-area open */
+	.close	= shm_close,	/* callback for when the vm-area is released */
+	.nopage	= shmem_nopage,
+#ifdef CONFIG_NUMA
+	.set_policy = shmem_set_policy,
+	.get_policy = shmem_get_policy,
+#endif
+};
+
+static int newseg (key_t key, int shmflg, size_t size)
+{
+	int error;
+	struct shmid_kernel *shp;
+	int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
+	struct file * file;
+	char name[13];
+	int id;
+
+	if (size < SHMMIN || size > shm_ctlmax)
+		return -EINVAL;
+
+	if (shm_tot + numpages >= shm_ctlall)
+		return -ENOSPC;
+
+	shp = ipc_rcu_alloc(sizeof(*shp));
+	if (!shp)
+		return -ENOMEM;
+
+	shp->shm_perm.key = key;
+	shp->shm_flags = (shmflg & S_IRWXUGO);
+	shp->mlock_user = NULL;
+
+	shp->shm_perm.security = NULL;
+	error = security_shm_alloc(shp);
+	if (error) {
+		ipc_rcu_putref(shp);
+		return error;
+	}
+
+	if (shmflg & SHM_HUGETLB) {
+		/* hugetlb_zero_setup takes care of mlock user accounting */
+		file = hugetlb_zero_setup(size);
+		shp->mlock_user = current->user;
+	} else {
+		sprintf (name, "SYSV%08x", key);
+		file = shmem_file_setup(name, size, VM_ACCOUNT);
+	}
+	error = PTR_ERR(file);
+	if (IS_ERR(file))
+		goto no_file;
+
+	error = -ENOSPC;
+	id = shm_addid(shp);
+	if(id == -1) 
+		goto no_id;
+
+	shp->shm_cprid = current->tgid;
+	shp->shm_lprid = 0;
+	shp->shm_atim = shp->shm_dtim = 0;
+	shp->shm_ctim = get_seconds();
+	shp->shm_segsz = size;
+	shp->shm_nattch = 0;
+	shp->id = shm_buildid(id,shp->shm_perm.seq);
+	shp->shm_file = file;
+	file->f_dentry->d_inode->i_ino = shp->id;
+	if (shmflg & SHM_HUGETLB)
+		set_file_hugepages(file);
+	else
+		file->f_op = &shm_file_operations;
+	shm_tot += numpages;
+	shm_unlock(shp);
+	return shp->id;
+
+no_id:
+	fput(file);
+no_file:
+	security_shm_free(shp);
+	ipc_rcu_putref(shp);
+	return error;
+}
+
+asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
+{
+	struct shmid_kernel *shp;
+	int err, id = 0;
+
+	down(&shm_ids.sem);
+	if (key == IPC_PRIVATE) {
+		err = newseg(key, shmflg, size);
+	} else if ((id = ipc_findkey(&shm_ids, key)) == -1) {
+		if (!(shmflg & IPC_CREAT))
+			err = -ENOENT;
+		else
+			err = newseg(key, shmflg, size);
+	} else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
+		err = -EEXIST;
+	} else {
+		shp = shm_lock(id);
+		if(shp==NULL)
+			BUG();
+		if (shp->shm_segsz < size)
+			err = -EINVAL;
+		else if (ipcperms(&shp->shm_perm, shmflg))
+			err = -EACCES;
+		else {
+			int shmid = shm_buildid(id, shp->shm_perm.seq);
+			err = security_shm_associate(shp, shmflg);
+			if (!err)
+				err = shmid;
+		}
+		shm_unlock(shp);
+	}
+	up(&shm_ids.sem);
+
+	return err;
+}
+
+static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
+{
+	switch(version) {
+	case IPC_64:
+		return copy_to_user(buf, in, sizeof(*in));
+	case IPC_OLD:
+	    {
+		struct shmid_ds out;
+
+		ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
+		out.shm_segsz	= in->shm_segsz;
+		out.shm_atime	= in->shm_atime;
+		out.shm_dtime	= in->shm_dtime;
+		out.shm_ctime	= in->shm_ctime;
+		out.shm_cpid	= in->shm_cpid;
+		out.shm_lpid	= in->shm_lpid;
+		out.shm_nattch	= in->shm_nattch;
+
+		return copy_to_user(buf, &out, sizeof(out));
+	    }
+	default:
+		return -EINVAL;
+	}
+}
+
+struct shm_setbuf {
+	uid_t	uid;
+	gid_t	gid;
+	mode_t	mode;
+};	
+
+static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version)
+{
+	switch(version) {
+	case IPC_64:
+	    {
+		struct shmid64_ds tbuf;
+
+		if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
+			return -EFAULT;
+
+		out->uid	= tbuf.shm_perm.uid;
+		out->gid	= tbuf.shm_perm.gid;
+		out->mode	= tbuf.shm_flags;
+
+		return 0;
+	    }
+	case IPC_OLD:
+	    {
+		struct shmid_ds tbuf_old;
+
+		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
+			return -EFAULT;
+
+		out->uid	= tbuf_old.shm_perm.uid;
+		out->gid	= tbuf_old.shm_perm.gid;
+		out->mode	= tbuf_old.shm_flags;
+
+		return 0;
+	    }
+	default:
+		return -EINVAL;
+	}
+}
+
+static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
+{
+	switch(version) {
+	case IPC_64:
+		return copy_to_user(buf, in, sizeof(*in));
+	case IPC_OLD:
+	    {
+		struct shminfo out;
+
+		if(in->shmmax > INT_MAX)
+			out.shmmax = INT_MAX;
+		else
+			out.shmmax = (int)in->shmmax;
+
+		out.shmmin	= in->shmmin;
+		out.shmmni	= in->shmmni;
+		out.shmseg	= in->shmseg;
+		out.shmall	= in->shmall; 
+
+		return copy_to_user(buf, &out, sizeof(out));
+	    }
+	default:
+		return -EINVAL;
+	}
+}
+
+static void shm_get_stat(unsigned long *rss, unsigned long *swp) 
+{
+	int i;
+
+	*rss = 0;
+	*swp = 0;
+
+	for (i = 0; i <= shm_ids.max_id; i++) {
+		struct shmid_kernel *shp;
+		struct inode *inode;
+
+		shp = shm_get(i);
+		if(!shp)
+			continue;
+
+		inode = shp->shm_file->f_dentry->d_inode;
+
+		if (is_file_hugepages(shp->shm_file)) {
+			struct address_space *mapping = inode->i_mapping;
+			*rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages;
+		} else {
+			struct shmem_inode_info *info = SHMEM_I(inode);
+			spin_lock(&info->lock);
+			*rss += inode->i_mapping->nrpages;
+			*swp += info->swapped;
+			spin_unlock(&info->lock);
+		}
+	}
+}
+
+asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
+{
+	struct shm_setbuf setbuf;
+	struct shmid_kernel *shp;
+	int err, version;
+
+	if (cmd < 0 || shmid < 0) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	version = ipc_parse_version(&cmd);
+
+	switch (cmd) { /* replace with proc interface ? */
+	case IPC_INFO:
+	{
+		struct shminfo64 shminfo;
+
+		err = security_shm_shmctl(NULL, cmd);
+		if (err)
+			return err;
+
+		memset(&shminfo,0,sizeof(shminfo));
+		shminfo.shmmni = shminfo.shmseg = shm_ctlmni;
+		shminfo.shmmax = shm_ctlmax;
+		shminfo.shmall = shm_ctlall;
+
+		shminfo.shmmin = SHMMIN;
+		if(copy_shminfo_to_user (buf, &shminfo, version))
+			return -EFAULT;
+		/* reading a integer is always atomic */
+		err= shm_ids.max_id;
+		if(err<0)
+			err = 0;
+		goto out;
+	}
+	case SHM_INFO:
+	{
+		struct shm_info shm_info;
+
+		err = security_shm_shmctl(NULL, cmd);
+		if (err)
+			return err;
+
+		memset(&shm_info,0,sizeof(shm_info));
+		down(&shm_ids.sem);
+		shm_info.used_ids = shm_ids.in_use;
+		shm_get_stat (&shm_info.shm_rss, &shm_info.shm_swp);
+		shm_info.shm_tot = shm_tot;
+		shm_info.swap_attempts = 0;
+		shm_info.swap_successes = 0;
+		err = shm_ids.max_id;
+		up(&shm_ids.sem);
+		if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
+			err = -EFAULT;
+			goto out;
+		}
+
+		err = err < 0 ? 0 : err;
+		goto out;
+	}
+	case SHM_STAT:
+	case IPC_STAT:
+	{
+		struct shmid64_ds tbuf;
+		int result;
+		memset(&tbuf, 0, sizeof(tbuf));
+		shp = shm_lock(shmid);
+		if(shp==NULL) {
+			err = -EINVAL;
+			goto out;
+		} else if(cmd==SHM_STAT) {
+			err = -EINVAL;
+			if (shmid > shm_ids.max_id)
+				goto out_unlock;
+			result = shm_buildid(shmid, shp->shm_perm.seq);
+		} else {
+			err = shm_checkid(shp,shmid);
+			if(err)
+				goto out_unlock;
+			result = 0;
+		}
+		err=-EACCES;
+		if (ipcperms (&shp->shm_perm, S_IRUGO))
+			goto out_unlock;
+		err = security_shm_shmctl(shp, cmd);
+		if (err)
+			goto out_unlock;
+		kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
+		tbuf.shm_segsz	= shp->shm_segsz;
+		tbuf.shm_atime	= shp->shm_atim;
+		tbuf.shm_dtime	= shp->shm_dtim;
+		tbuf.shm_ctime	= shp->shm_ctim;
+		tbuf.shm_cpid	= shp->shm_cprid;
+		tbuf.shm_lpid	= shp->shm_lprid;
+		if (!is_file_hugepages(shp->shm_file))
+			tbuf.shm_nattch	= shp->shm_nattch;
+		else
+			tbuf.shm_nattch = file_count(shp->shm_file) - 1;
+		shm_unlock(shp);
+		if(copy_shmid_to_user (buf, &tbuf, version))
+			err = -EFAULT;
+		else
+			err = result;
+		goto out;
+	}
+	case SHM_LOCK:
+	case SHM_UNLOCK:
+	{
+		shp = shm_lock(shmid);
+		if(shp==NULL) {
+			err = -EINVAL;
+			goto out;
+		}
+		err = shm_checkid(shp,shmid);
+		if(err)
+			goto out_unlock;
+
+		if (!capable(CAP_IPC_LOCK)) {
+			err = -EPERM;
+			if (current->euid != shp->shm_perm.uid &&
+			    current->euid != shp->shm_perm.cuid)
+				goto out_unlock;
+			if (cmd == SHM_LOCK &&
+			    !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
+				goto out_unlock;
+		}
+
+		err = security_shm_shmctl(shp, cmd);
+		if (err)
+			goto out_unlock;
+		
+		if(cmd==SHM_LOCK) {
+			struct user_struct * user = current->user;
+			if (!is_file_hugepages(shp->shm_file)) {
+				err = shmem_lock(shp->shm_file, 1, user);
+				if (!err) {
+					shp->shm_flags |= SHM_LOCKED;
+					shp->mlock_user = user;
+				}
+			}
+		} else if (!is_file_hugepages(shp->shm_file)) {
+			shmem_lock(shp->shm_file, 0, shp->mlock_user);
+			shp->shm_flags &= ~SHM_LOCKED;
+			shp->mlock_user = NULL;
+		}
+		shm_unlock(shp);
+		goto out;
+	}
+	case IPC_RMID:
+	{
+		/*
+		 *	We cannot simply remove the file. The SVID states
+		 *	that the block remains until the last person
+		 *	detaches from it, then is deleted. A shmat() on
+		 *	an RMID segment is legal in older Linux and if 
+		 *	we change it apps break...
+		 *
+		 *	Instead we set a destroyed flag, and then blow
+		 *	the name away when the usage hits zero.
+		 */
+		down(&shm_ids.sem);
+		shp = shm_lock(shmid);
+		err = -EINVAL;
+		if (shp == NULL) 
+			goto out_up;
+		err = shm_checkid(shp, shmid);
+		if(err)
+			goto out_unlock_up;
+
+		if (current->euid != shp->shm_perm.uid &&
+		    current->euid != shp->shm_perm.cuid && 
+		    !capable(CAP_SYS_ADMIN)) {
+			err=-EPERM;
+			goto out_unlock_up;
+		}
+
+		err = security_shm_shmctl(shp, cmd);
+		if (err)
+			goto out_unlock_up;
+
+		if (shp->shm_nattch){
+			shp->shm_flags |= SHM_DEST;
+			/* Do not find it any more */
+			shp->shm_perm.key = IPC_PRIVATE;
+			shm_unlock(shp);
+		} else
+			shm_destroy (shp);
+		up(&shm_ids.sem);
+		goto out;
+	}
+
+	case IPC_SET:
+	{
+		if (copy_shmid_from_user (&setbuf, buf, version)) {
+			err = -EFAULT;
+			goto out;
+		}
+		if ((err = audit_ipc_perms(0, setbuf.uid, setbuf.gid, setbuf.mode)))
+			return err;
+		down(&shm_ids.sem);
+		shp = shm_lock(shmid);
+		err=-EINVAL;
+		if(shp==NULL)
+			goto out_up;
+		err = shm_checkid(shp,shmid);
+		if(err)
+			goto out_unlock_up;
+		err=-EPERM;
+		if (current->euid != shp->shm_perm.uid &&
+		    current->euid != shp->shm_perm.cuid && 
+		    !capable(CAP_SYS_ADMIN)) {
+			goto out_unlock_up;
+		}
+
+		err = security_shm_shmctl(shp, cmd);
+		if (err)
+			goto out_unlock_up;
+		
+		shp->shm_perm.uid = setbuf.uid;
+		shp->shm_perm.gid = setbuf.gid;
+		shp->shm_flags = (shp->shm_flags & ~S_IRWXUGO)
+			| (setbuf.mode & S_IRWXUGO);
+		shp->shm_ctim = get_seconds();
+		break;
+	}
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+
+	err = 0;
+out_unlock_up:
+	shm_unlock(shp);
+out_up:
+	up(&shm_ids.sem);
+	goto out;
+out_unlock:
+	shm_unlock(shp);
+out:
+	return err;
+}
+
+/*
+ * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
+ *
+ * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
+ * "raddr" thing points to kernel space, and there has to be a wrapper around
+ * this.
+ */
+long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
+{
+	struct shmid_kernel *shp;
+	unsigned long addr;
+	unsigned long size;
+	struct file * file;
+	int    err;
+	unsigned long flags;
+	unsigned long prot;
+	unsigned long o_flags;
+	int acc_mode;
+	void *user_addr;
+
+	if (shmid < 0) {
+		err = -EINVAL;
+		goto out;
+	} else if ((addr = (ulong)shmaddr)) {
+		if (addr & (SHMLBA-1)) {
+			if (shmflg & SHM_RND)
+				addr &= ~(SHMLBA-1);	   /* round down */
+			else
+#ifndef __ARCH_FORCE_SHMLBA
+				if (addr & ~PAGE_MASK)
+#endif
+					return -EINVAL;
+		}
+		flags = MAP_SHARED | MAP_FIXED;
+	} else {
+		if ((shmflg & SHM_REMAP))
+			return -EINVAL;
+
+		flags = MAP_SHARED;
+	}
+
+	if (shmflg & SHM_RDONLY) {
+		prot = PROT_READ;
+		o_flags = O_RDONLY;
+		acc_mode = S_IRUGO;
+	} else {
+		prot = PROT_READ | PROT_WRITE;
+		o_flags = O_RDWR;
+		acc_mode = S_IRUGO | S_IWUGO;
+	}
+	if (shmflg & SHM_EXEC) {
+		prot |= PROT_EXEC;
+		acc_mode |= S_IXUGO;
+	}
+
+	/*
+	 * We cannot rely on the fs check since SYSV IPC does have an
+	 * additional creator id...
+	 */
+	shp = shm_lock(shmid);
+	if(shp == NULL) {
+		err = -EINVAL;
+		goto out;
+	}
+	err = shm_checkid(shp,shmid);
+	if (err) {
+		shm_unlock(shp);
+		goto out;
+	}
+	if (ipcperms(&shp->shm_perm, acc_mode)) {
+		shm_unlock(shp);
+		err = -EACCES;
+		goto out;
+	}
+
+	err = security_shm_shmat(shp, shmaddr, shmflg);
+	if (err) {
+		shm_unlock(shp);
+		return err;
+	}
+		
+	file = shp->shm_file;
+	size = i_size_read(file->f_dentry->d_inode);
+	shp->shm_nattch++;
+	shm_unlock(shp);
+
+	down_write(&current->mm->mmap_sem);
+	if (addr && !(shmflg & SHM_REMAP)) {
+		user_addr = ERR_PTR(-EINVAL);
+		if (find_vma_intersection(current->mm, addr, addr + size))
+			goto invalid;
+		/*
+		 * If shm segment goes below stack, make sure there is some
+		 * space left for the stack to grow (at least 4 pages).
+		 */
+		if (addr < current->mm->start_stack &&
+		    addr > current->mm->start_stack - size - PAGE_SIZE * 5)
+			goto invalid;
+	}
+		
+	user_addr = (void*) do_mmap (file, addr, size, prot, flags, 0);
+
+invalid:
+	up_write(&current->mm->mmap_sem);
+
+	down (&shm_ids.sem);
+	if(!(shp = shm_lock(shmid)))
+		BUG();
+	shp->shm_nattch--;
+	if(shp->shm_nattch == 0 &&
+	   shp->shm_flags & SHM_DEST)
+		shm_destroy (shp);
+	else
+		shm_unlock(shp);
+	up (&shm_ids.sem);
+
+	*raddr = (unsigned long) user_addr;
+	err = 0;
+	if (IS_ERR(user_addr))
+		err = PTR_ERR(user_addr);
+out:
+	return err;
+}
+
+/*
+ * detach and kill segment if marked destroyed.
+ * The work is done in shm_close.
+ */
+asmlinkage long sys_shmdt(char __user *shmaddr)
+{
+	struct mm_struct *mm = current->mm;
+	struct vm_area_struct *vma, *next;
+	unsigned long addr = (unsigned long)shmaddr;
+	loff_t size = 0;
+	int retval = -EINVAL;
+
+	down_write(&mm->mmap_sem);
+
+	/*
+	 * This function tries to be smart and unmap shm segments that
+	 * were modified by partial mlock or munmap calls:
+	 * - It first determines the size of the shm segment that should be
+	 *   unmapped: It searches for a vma that is backed by shm and that
+	 *   started at address shmaddr. It records it's size and then unmaps
+	 *   it.
+	 * - Then it unmaps all shm vmas that started at shmaddr and that
+	 *   are within the initially determined size.
+	 * Errors from do_munmap are ignored: the function only fails if
+	 * it's called with invalid parameters or if it's called to unmap
+	 * a part of a vma. Both calls in this function are for full vmas,
+	 * the parameters are directly copied from the vma itself and always
+	 * valid - therefore do_munmap cannot fail. (famous last words?)
+	 */
+	/*
+	 * If it had been mremap()'d, the starting address would not
+	 * match the usual checks anyway. So assume all vma's are
+	 * above the starting address given.
+	 */
+	vma = find_vma(mm, addr);
+
+	while (vma) {
+		next = vma->vm_next;
+
+		/*
+		 * Check if the starting address would match, i.e. it's
+		 * a fragment created by mprotect() and/or munmap(), or it
+		 * otherwise it starts at this address with no hassles.
+		 */
+		if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) &&
+			(vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
+
+
+			size = vma->vm_file->f_dentry->d_inode->i_size;
+			do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+			/*
+			 * We discovered the size of the shm segment, so
+			 * break out of here and fall through to the next
+			 * loop that uses the size information to stop
+			 * searching for matching vma's.
+			 */
+			retval = 0;
+			vma = next;
+			break;
+		}
+		vma = next;
+	}
+
+	/*
+	 * We need look no further than the maximum address a fragment
+	 * could possibly have landed at. Also cast things to loff_t to
+	 * prevent overflows and make comparisions vs. equal-width types.
+	 */
+	while (vma && (loff_t)(vma->vm_end - addr) <= size) {
+		next = vma->vm_next;
+
+		/* finding a matching vma now does not alter retval */
+		if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) &&
+			(vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
+
+			do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+		vma = next;
+	}
+
+	up_write(&mm->mmap_sem);
+	return retval;
+}
+
+#ifdef CONFIG_PROC_FS
+static int sysvipc_shm_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
+{
+	off_t pos = 0;
+	off_t begin = 0;
+	int i, len = 0;
+
+	down(&shm_ids.sem);
+	len += sprintf(buffer, "       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime\n");
+
+	for(i = 0; i <= shm_ids.max_id; i++) {
+		struct shmid_kernel* shp;
+
+		shp = shm_lock(i);
+		if(shp!=NULL) {
+#define SMALL_STRING "%10d %10d  %4o %10u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
+#define BIG_STRING   "%10d %10d  %4o %21u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
+			char *format;
+
+			if (sizeof(size_t) <= sizeof(int))
+				format = SMALL_STRING;
+			else
+				format = BIG_STRING;
+			len += sprintf(buffer + len, format,
+				shp->shm_perm.key,
+				shm_buildid(i, shp->shm_perm.seq),
+				shp->shm_flags,
+				shp->shm_segsz,
+				shp->shm_cprid,
+				shp->shm_lprid,
+				is_file_hugepages(shp->shm_file) ? (file_count(shp->shm_file) - 1) : shp->shm_nattch,
+				shp->shm_perm.uid,
+				shp->shm_perm.gid,
+				shp->shm_perm.cuid,
+				shp->shm_perm.cgid,
+				shp->shm_atim,
+				shp->shm_dtim,
+				shp->shm_ctim);
+			shm_unlock(shp);
+
+			pos += len;
+			if(pos < offset) {
+				len = 0;
+				begin = pos;
+			}
+			if(pos > offset + length)
+				goto done;
+		}
+	}
+	*eof = 1;
+done:
+	up(&shm_ids.sem);
+	*start = buffer + (offset - begin);
+	len -= (offset - begin);
+	if(len > length)
+		len = length;
+	if(len < 0)
+		len = 0;
+	return len;
+}
+#endif
diff --git a/ipc/util.c b/ipc/util.c
new file mode 100644
index 0000000..e00c35f
--- /dev/null
+++ b/ipc/util.c
@@ -0,0 +1,580 @@
+/*
+ * linux/ipc/util.c
+ * Copyright (C) 1992 Krishna Balasubramanian
+ *
+ * Sep 1997 - Call suser() last after "normal" permission checks so we
+ *            get BSD style process accounting right.
+ *            Occurs in several places in the IPC code.
+ *            Chris Evans, <chris@ferret.lmh.ox.ac.uk>
+ * Nov 1999 - ipc helper functions, unified SMP locking
+ *	      Manfred Spraul <manfreds@colorfullife.com>
+ * Oct 2002 - One lock per IPC id. RCU ipc_free for lock-free grow_ary().
+ *            Mingming Cao <cmm@us.ibm.com>
+ */
+
+#include <linux/config.h>
+#include <linux/mm.h>
+#include <linux/shm.h>
+#include <linux/init.h>
+#include <linux/msg.h>
+#include <linux/smp_lock.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/highuid.h>
+#include <linux/security.h>
+#include <linux/rcupdate.h>
+#include <linux/workqueue.h>
+
+#include <asm/unistd.h>
+
+#include "util.h"
+
+/**
+ *	ipc_init	-	initialise IPC subsystem
+ *
+ *	The various system5 IPC resources (semaphores, messages and shared
+ *	memory are initialised
+ */
+ 
+static int __init ipc_init(void)
+{
+	sem_init();
+	msg_init();
+	shm_init();
+	return 0;
+}
+__initcall(ipc_init);
+
+/**
+ *	ipc_init_ids		-	initialise IPC identifiers
+ *	@ids: Identifier set
+ *	@size: Number of identifiers
+ *
+ *	Given a size for the ipc identifier range (limited below IPCMNI)
+ *	set up the sequence range to use then allocate and initialise the
+ *	array itself. 
+ */
+ 
+void __init ipc_init_ids(struct ipc_ids* ids, int size)
+{
+	int i;
+	sema_init(&ids->sem,1);
+
+	if(size > IPCMNI)
+		size = IPCMNI;
+	ids->in_use = 0;
+	ids->max_id = -1;
+	ids->seq = 0;
+	{
+		int seq_limit = INT_MAX/SEQ_MULTIPLIER;
+		if(seq_limit > USHRT_MAX)
+			ids->seq_max = USHRT_MAX;
+		 else
+		 	ids->seq_max = seq_limit;
+	}
+
+	ids->entries = ipc_rcu_alloc(sizeof(struct kern_ipc_perm *)*size +
+				     sizeof(struct ipc_id_ary));
+
+	if(ids->entries == NULL) {
+		printk(KERN_ERR "ipc_init_ids() failed, ipc service disabled.\n");
+		size = 0;
+		ids->entries = &ids->nullentry;
+	}
+	ids->entries->size = size;
+	for(i=0;i<size;i++)
+		ids->entries->p[i] = NULL;
+}
+
+/**
+ *	ipc_findkey	-	find a key in an ipc identifier set	
+ *	@ids: Identifier set
+ *	@key: The key to find
+ *	
+ *	Requires ipc_ids.sem locked.
+ *	Returns the identifier if found or -1 if not.
+ */
+ 
+int ipc_findkey(struct ipc_ids* ids, key_t key)
+{
+	int id;
+	struct kern_ipc_perm* p;
+	int max_id = ids->max_id;
+
+	/*
+	 * rcu_dereference() is not needed here
+	 * since ipc_ids.sem is held
+	 */
+	for (id = 0; id <= max_id; id++) {
+		p = ids->entries->p[id];
+		if(p==NULL)
+			continue;
+		if (key == p->key)
+			return id;
+	}
+	return -1;
+}
+
+/*
+ * Requires ipc_ids.sem locked
+ */
+static int grow_ary(struct ipc_ids* ids, int newsize)
+{
+	struct ipc_id_ary* new;
+	struct ipc_id_ary* old;
+	int i;
+	int size = ids->entries->size;
+
+	if(newsize > IPCMNI)
+		newsize = IPCMNI;
+	if(newsize <= size)
+		return newsize;
+
+	new = ipc_rcu_alloc(sizeof(struct kern_ipc_perm *)*newsize +
+			    sizeof(struct ipc_id_ary));
+	if(new == NULL)
+		return size;
+	new->size = newsize;
+	memcpy(new->p, ids->entries->p, sizeof(struct kern_ipc_perm *)*size +
+					sizeof(struct ipc_id_ary));
+	for(i=size;i<newsize;i++) {
+		new->p[i] = NULL;
+	}
+	old = ids->entries;
+
+	/*
+	 * Use rcu_assign_pointer() to make sure the memcpyed contents
+	 * of the new array are visible before the new array becomes visible.
+	 */
+	rcu_assign_pointer(ids->entries, new);
+
+	ipc_rcu_putref(old);
+	return newsize;
+}
+
+/**
+ *	ipc_addid 	-	add an IPC identifier
+ *	@ids: IPC identifier set
+ *	@new: new IPC permission set
+ *	@size: new size limit for the id array
+ *
+ *	Add an entry 'new' to the IPC arrays. The permissions object is
+ *	initialised and the first free entry is set up and the id assigned
+ *	is returned. The list is returned in a locked state on success.
+ *	On failure the list is not locked and -1 is returned.
+ *
+ *	Called with ipc_ids.sem held.
+ */
+ 
+int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
+{
+	int id;
+
+	size = grow_ary(ids,size);
+
+	/*
+	 * rcu_dereference()() is not needed here since
+	 * ipc_ids.sem is held
+	 */
+	for (id = 0; id < size; id++) {
+		if(ids->entries->p[id] == NULL)
+			goto found;
+	}
+	return -1;
+found:
+	ids->in_use++;
+	if (id > ids->max_id)
+		ids->max_id = id;
+
+	new->cuid = new->uid = current->euid;
+	new->gid = new->cgid = current->egid;
+
+	new->seq = ids->seq++;
+	if(ids->seq > ids->seq_max)
+		ids->seq = 0;
+
+	spin_lock_init(&new->lock);
+	new->deleted = 0;
+	rcu_read_lock();
+	spin_lock(&new->lock);
+	ids->entries->p[id] = new;
+	return id;
+}
+
+/**
+ *	ipc_rmid	-	remove an IPC identifier
+ *	@ids: identifier set
+ *	@id: Identifier to remove
+ *
+ *	The identifier must be valid, and in use. The kernel will panic if
+ *	fed an invalid identifier. The entry is removed and internal
+ *	variables recomputed. The object associated with the identifier
+ *	is returned.
+ *	ipc_ids.sem and the spinlock for this ID is hold before this function
+ *	is called, and remain locked on the exit.
+ */
+ 
+struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id)
+{
+	struct kern_ipc_perm* p;
+	int lid = id % SEQ_MULTIPLIER;
+	if(lid >= ids->entries->size)
+		BUG();
+
+	/* 
+	 * do not need a rcu_dereference()() here to force ordering
+	 * on Alpha, since the ipc_ids.sem is held.
+	 */	
+	p = ids->entries->p[lid];
+	ids->entries->p[lid] = NULL;
+	if(p==NULL)
+		BUG();
+	ids->in_use--;
+
+	if (lid == ids->max_id) {
+		do {
+			lid--;
+			if(lid == -1)
+				break;
+		} while (ids->entries->p[lid] == NULL);
+		ids->max_id = lid;
+	}
+	p->deleted = 1;
+	return p;
+}
+
+/**
+ *	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
+ */
+ 
+void* ipc_alloc(int size)
+{
+	void* out;
+	if(size > PAGE_SIZE)
+		out = vmalloc(size);
+	else
+		out = kmalloc(size, GFP_KERNEL);
+	return out;
+}
+
+/**
+ *	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.
+ */
+
+void ipc_free(void* ptr, int size)
+{
+	if(size > PAGE_SIZE)
+		vfree(ptr);
+	else
+		kfree(ptr);
+}
+
+/*
+ * rcu allocations:
+ * There are three headers that are prepended to the actual allocation:
+ * - during use: ipc_rcu_hdr.
+ * - during the rcu grace period: ipc_rcu_grace.
+ * - [only if vmalloc]: ipc_rcu_sched.
+ * Their lifetime doesn't overlap, thus the headers share the same memory.
+ * Unlike a normal union, they are right-aligned, thus some container_of
+ * forward/backward casting is necessary:
+ */
+struct ipc_rcu_hdr
+{
+	int refcount;
+	int is_vmalloc;
+	void *data[0];
+};
+
+
+struct ipc_rcu_grace
+{
+	struct rcu_head rcu;
+	/* "void *" makes sure alignment of following data is sane. */
+	void *data[0];
+};
+
+struct ipc_rcu_sched
+{
+	struct work_struct work;
+	/* "void *" makes sure alignment of following data is sane. */
+	void *data[0];
+};
+
+#define HDRLEN_KMALLOC		(sizeof(struct ipc_rcu_grace) > sizeof(struct ipc_rcu_hdr) ? \
+					sizeof(struct ipc_rcu_grace) : sizeof(struct ipc_rcu_hdr))
+#define HDRLEN_VMALLOC		(sizeof(struct ipc_rcu_sched) > HDRLEN_KMALLOC ? \
+					sizeof(struct ipc_rcu_sched) : HDRLEN_KMALLOC)
+
+static inline int rcu_use_vmalloc(int size)
+{
+	/* Too big for a single page? */
+	if (HDRLEN_KMALLOC + size > PAGE_SIZE)
+		return 1;
+	return 0;
+}
+
+/**
+ *	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.
+ *	NULL is returned if the allocation fails. 
+ */
+ 
+void* ipc_rcu_alloc(int size)
+{
+	void* out;
+	/* 
+	 * We prepend the allocation with the rcu struct, and
+	 * workqueue if necessary (for vmalloc). 
+	 */
+	if (rcu_use_vmalloc(size)) {
+		out = vmalloc(HDRLEN_VMALLOC + size);
+		if (out) {
+			out += HDRLEN_VMALLOC;
+			container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 1;
+			container_of(out, struct ipc_rcu_hdr, data)->refcount = 1;
+		}
+	} else {
+		out = kmalloc(HDRLEN_KMALLOC + size, GFP_KERNEL);
+		if (out) {
+			out += HDRLEN_KMALLOC;
+			container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 0;
+			container_of(out, struct ipc_rcu_hdr, data)->refcount = 1;
+		}
+	}
+
+	return out;
+}
+
+void ipc_rcu_getref(void *ptr)
+{
+	container_of(ptr, struct ipc_rcu_hdr, data)->refcount++;
+}
+
+/**
+ *	ipc_schedule_free	- free ipc + rcu space
+ * 
+ * Since RCU callback function is called in bh,
+ * we need to defer the vfree to schedule_work
+ */
+static void ipc_schedule_free(struct rcu_head *head)
+{
+	struct ipc_rcu_grace *grace =
+		container_of(head, struct ipc_rcu_grace, rcu);
+	struct ipc_rcu_sched *sched =
+			container_of(&(grace->data[0]), struct ipc_rcu_sched, data[0]);
+
+	INIT_WORK(&sched->work, vfree, sched);
+	schedule_work(&sched->work);
+}
+
+/**
+ *	ipc_immediate_free	- free ipc + rcu space
+ *
+ *	Free from the RCU callback context
+ *
+ */
+static void ipc_immediate_free(struct rcu_head *head)
+{
+	struct ipc_rcu_grace *free =
+		container_of(head, struct ipc_rcu_grace, rcu);
+	kfree(free);
+}
+
+void ipc_rcu_putref(void *ptr)
+{
+	if (--container_of(ptr, struct ipc_rcu_hdr, data)->refcount > 0)
+		return;
+
+	if (container_of(ptr, struct ipc_rcu_hdr, data)->is_vmalloc) {
+		call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
+				ipc_schedule_free);
+	} else {
+		call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
+				ipc_immediate_free);
+	}
+}
+
+/**
+ *	ipcperms	-	check IPC permissions
+ *	@ipcp: IPC permission set
+ *	@flag: desired permission set.
+ *
+ *	Check user, group, other permissions for access
+ *	to ipc resources. return 0 if allowed
+ */
+ 
+int ipcperms (struct kern_ipc_perm *ipcp, short flag)
+{	/* flag will most probably be 0 or S_...UGO from <linux/stat.h> */
+	int requested_mode, granted_mode;
+
+	requested_mode = (flag >> 6) | (flag >> 3) | flag;
+	granted_mode = ipcp->mode;
+	if (current->euid == ipcp->cuid || current->euid == ipcp->uid)
+		granted_mode >>= 6;
+	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) && 
+	    !capable(CAP_IPC_OWNER))
+		return -1;
+
+	return security_ipc_permission(ipcp, flag);
+}
+
+/*
+ * Functions to convert between the kern_ipc_perm structure and the
+ * old/new ipc_perm structures
+ */
+
+/**
+ *	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).
+ */
+ 
+
+void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
+{
+	out->key	= in->key;
+	out->uid	= in->uid;
+	out->gid	= in->gid;
+	out->cuid	= in->cuid;
+	out->cgid	= in->cgid;
+	out->mode	= in->mode;
+	out->seq	= in->seq;
+}
+
+/**
+ *	ipc64_perm_to_ipc_perm	-	convert old ipc permissions to new
+ *	@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.
+ */
+ 
+void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
+{
+	out->key	= in->key;
+	SET_UID(out->uid, in->uid);
+	SET_GID(out->gid, in->gid);
+	SET_UID(out->cuid, in->cuid);
+	SET_GID(out->cgid, in->cgid);
+	out->mode	= in->mode;
+	out->seq	= in->seq;
+}
+
+/*
+ * So far only shm_get_stat() calls ipc_get() via shm_get(), so ipc_get()
+ * is called with shm_ids.sem locked.  Since grow_ary() is also called with
+ * shm_ids.sem down(for Shared Memory), there is no need to add read 
+ * barriers here to gurantee the writes in grow_ary() are seen in order 
+ * here (for Alpha).
+ *
+ * However ipc_get() itself does not necessary require ipc_ids.sem down. So
+ * if in the future ipc_get() is used by other places without ipc_ids.sem
+ * down, then ipc_get() needs read memery barriers as ipc_lock() does.
+ */
+struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id)
+{
+	struct kern_ipc_perm* out;
+	int lid = id % SEQ_MULTIPLIER;
+	if(lid >= ids->entries->size)
+		return NULL;
+	out = ids->entries->p[lid];
+	return out;
+}
+
+struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id)
+{
+	struct kern_ipc_perm* out;
+	int lid = id % SEQ_MULTIPLIER;
+	struct ipc_id_ary* entries;
+
+	rcu_read_lock();
+	entries = rcu_dereference(ids->entries);
+	if(lid >= entries->size) {
+		rcu_read_unlock();
+		return NULL;
+	}
+	out = entries->p[lid];
+	if(out == NULL) {
+		rcu_read_unlock();
+		return NULL;
+	}
+	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
+	 */
+	if (out->deleted) {
+		spin_unlock(&out->lock);
+		rcu_read_unlock();
+		return NULL;
+	}
+	return out;
+}
+
+void ipc_lock_by_ptr(struct kern_ipc_perm *perm)
+{
+	rcu_read_lock();
+	spin_lock(&perm->lock);
+}
+
+void ipc_unlock(struct kern_ipc_perm* perm)
+{
+	spin_unlock(&perm->lock);
+	rcu_read_unlock();
+}
+
+int ipc_buildid(struct ipc_ids* ids, int id, int seq)
+{
+	return SEQ_MULTIPLIER*seq + id;
+}
+
+int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid)
+{
+	if(uid/SEQ_MULTIPLIER != ipcp->seq)
+		return 1;
+	return 0;
+}
+
+#ifdef __ARCH_WANT_IPC_PARSE_VERSION
+
+
+/**
+ *	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.
+ */
+ 
+int ipc_parse_version (int *cmd)
+{
+	if (*cmd & IPC_64) {
+		*cmd ^= IPC_64;
+		return IPC_64;
+	} else {
+		return IPC_OLD;
+	}
+}
+
+#endif /* __ARCH_WANT_IPC_PARSE_VERSION */
diff --git a/ipc/util.h b/ipc/util.h
new file mode 100644
index 0000000..07d6894
--- /dev/null
+++ b/ipc/util.h
@@ -0,0 +1,81 @@
+/*
+ * linux/ipc/util.h
+ * Copyright (C) 1999 Christoph Rohland
+ *
+ * ipc helper functions (c) 1999 Manfred Spraul <manfreds@colorfullife.com>
+ */
+
+#ifndef _IPC_UTIL_H
+#define _IPC_UTIL_H
+
+#define USHRT_MAX 0xffff
+#define SEQ_MULTIPLIER	(IPCMNI)
+
+void sem_init (void);
+void msg_init (void);
+void shm_init (void);
+
+struct ipc_id_ary {
+	int size;
+	struct kern_ipc_perm *p[0];
+};
+
+struct ipc_ids {
+	int in_use;
+	int max_id;
+	unsigned short seq;
+	unsigned short seq_max;
+	struct semaphore sem;	
+	struct ipc_id_ary nullentry;
+	struct ipc_id_ary* entries;
+};
+
+void __init ipc_init_ids(struct ipc_ids* ids, int size);
+
+/* must be called with ids->sem acquired.*/
+int ipc_findkey(struct ipc_ids* ids, key_t key);
+int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size);
+
+/* must be called with both locks acquired. */
+struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
+
+int ipcperms (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);
+void ipc_rcu_getref(void *ptr);
+void ipc_rcu_putref(void *ptr);
+
+struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);
+struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);
+void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp);
+void ipc_unlock(struct kern_ipc_perm* perm);
+int ipc_buildid(struct ipc_ids* ids, int id, int seq);
+int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid);
+
+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);
+
+#if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__)
+  /* 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, int len);
+extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
+
+#endif