initial_commit

1 files changed, 1123 insertions, 0 deletions

diff --git a/ipc/shm.c b/ipc/shm.c
new file mode 100644
index 00000000..ab3385a2
--- /dev/null
+++ b/ipc/shm.c
@@ -0,0 +1,1123 @@
+/*
+ * 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>
+ *
+ * support for audit of ipc object properties and permission changes
+ * Dustin Kirkland <dustin.kirkland@us.ibm.com>
+ *
+ * namespaces support
+ * OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
+ */
+
+#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/shmem_fs.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+#include <linux/capability.h>
+#include <linux/ptrace.h>
+#include <linux/seq_file.h>
+#include <linux/rwsem.h>
+#include <linux/nsproxy.h>
+#include <linux/mount.h>
+#include <linux/ipc_namespace.h>
+
+#include <asm/uaccess.h>
+
+#include "util.h"
+
+struct shm_file_data {
+	int id;
+	struct ipc_namespace *ns;
+	struct file *file;
+	const struct vm_operations_struct *vm_ops;
+};
+
+#define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data))
+
+static const struct file_operations shm_file_operations;
+static const struct vm_operations_struct shm_vm_ops;
+
+#define shm_ids(ns)	((ns)->ids[IPC_SHM_IDS])
+
+#define shm_unlock(shp)			\
+	ipc_unlock(&(shp)->shm_perm)
+
+static int newseg(struct ipc_namespace *, struct ipc_params *);
+static void shm_open(struct vm_area_struct *vma);
+static void shm_close(struct vm_area_struct *vma);
+static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
+#ifdef CONFIG_PROC_FS
+static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
+#endif
+
+void shm_init_ns(struct ipc_namespace *ns)
+{
+	ns->shm_ctlmax = SHMMAX;
+	ns->shm_ctlall = SHMALL;
+	ns->shm_ctlmni = SHMMNI;
+	ns->shm_tot = 0;
+	ipc_init_ids(&shm_ids(ns));
+}
+
+/*
+ * Called with shm_ids.rw_mutex (writer) and the shp structure locked.
+ * Only shm_ids.rw_mutex remains locked on exit.
+ */
+static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
+{
+	struct shmid_kernel *shp;
+	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+	if (shp->shm_nattch){
+		shp->shm_perm.mode |= SHM_DEST;
+		/* Do not find it any more */
+		shp->shm_perm.key = IPC_PRIVATE;
+		shm_unlock(shp);
+	} else
+		shm_destroy(ns, shp);
+}
+
+#ifdef CONFIG_IPC_NS
+void shm_exit_ns(struct ipc_namespace *ns)
+{
+	free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
+	idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
+}
+#endif
+
+void __init shm_init (void)
+{
+	shm_init_ns(&init_ipc_ns);
+	ipc_init_proc_interface("sysvipc/shm",
+#if BITS_PER_LONG <= 32
+				"       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime        rss       swap\n",
+#else
+				"       key      shmid perms                  size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime                   rss                  swap\n",
+#endif
+				IPC_SHM_IDS, sysvipc_shm_proc_show);
+}
+
+/*
+ * shm_lock_(check_) routines are called in the paths where the rw_mutex
+ * is not necessarily held.
+ */
+static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
+{
+	struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
+
+	if (IS_ERR(ipcp))
+		return (struct shmid_kernel *)ipcp;
+
+	return container_of(ipcp, struct shmid_kernel, shm_perm);
+}
+
+static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns,
+						int id)
+{
+	struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id);
+
+	if (IS_ERR(ipcp))
+		return (struct shmid_kernel *)ipcp;
+
+	return container_of(ipcp, struct shmid_kernel, shm_perm);
+}
+
+static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
+{
+	ipc_rmid(&shm_ids(ns), &s->shm_perm);
+}
+
+
+/* This is called by fork, once for every shm attach. */
+static void shm_open(struct vm_area_struct *vma)
+{
+	struct file *file = vma->vm_file;
+	struct shm_file_data *sfd = shm_file_data(file);
+	struct shmid_kernel *shp;
+
+	shp = shm_lock(sfd->ns, sfd->id);
+	BUG_ON(IS_ERR(shp));
+	shp->shm_atim = get_seconds();
+	shp->shm_lprid = task_tgid_vnr(current);
+	shp->shm_nattch++;
+	shm_unlock(shp);
+}
+
+/*
+ * shm_destroy - free the struct shmid_kernel
+ *
+ * @ns: namespace
+ * @shp: struct to free
+ *
+ * It has to be called with shp and shm_ids.rw_mutex (writer) locked,
+ * but returns with shp unlocked and freed.
+ */
+static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
+{
+	ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	shm_rmid(ns, shp);
+	shm_unlock(shp);
+	if (!is_file_hugepages(shp->shm_file))
+		shmem_lock(shp->shm_file, 0, shp->mlock_user);
+	else if (shp->mlock_user)
+		user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size,
+						shp->mlock_user);
+	fput (shp->shm_file);
+	security_shm_free(shp);
+	ipc_rcu_putref(shp);
+}
+
+/*
+ * remove the attach descriptor vma.
+ * 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 *vma)
+{
+	struct file * file = vma->vm_file;
+	struct shm_file_data *sfd = shm_file_data(file);
+	struct shmid_kernel *shp;
+	struct ipc_namespace *ns = sfd->ns;
+
+	down_write(&shm_ids(ns).rw_mutex);
+	/* remove from the list of attaches of the shm segment */
+	shp = shm_lock(ns, sfd->id);
+	BUG_ON(IS_ERR(shp));
+	shp->shm_lprid = task_tgid_vnr(current);
+	shp->shm_dtim = get_seconds();
+	shp->shm_nattch--;
+	if(shp->shm_nattch == 0 &&
+	   shp->shm_perm.mode & SHM_DEST)
+		shm_destroy(ns, shp);
+	else
+		shm_unlock(shp);
+	up_write(&shm_ids(ns).rw_mutex);
+}
+
+static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct file *file = vma->vm_file;
+	struct shm_file_data *sfd = shm_file_data(file);
+
+	return sfd->vm_ops->fault(vma, vmf);
+}
+
+#ifdef CONFIG_NUMA
+static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
+{
+	struct file *file = vma->vm_file;
+	struct shm_file_data *sfd = shm_file_data(file);
+	int err = 0;
+	if (sfd->vm_ops->set_policy)
+		err = sfd->vm_ops->set_policy(vma, new);
+	return err;
+}
+
+static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
+					unsigned long addr)
+{
+	struct file *file = vma->vm_file;
+	struct shm_file_data *sfd = shm_file_data(file);
+	struct mempolicy *pol = NULL;
+
+	if (sfd->vm_ops->get_policy)
+		pol = sfd->vm_ops->get_policy(vma, addr);
+	else if (vma->vm_policy)
+		pol = vma->vm_policy;
+
+	return pol;
+}
+#endif
+
+static int shm_mmap(struct file * file, struct vm_area_struct * vma)
+{
+	struct shm_file_data *sfd = shm_file_data(file);
+	int ret;
+
+	ret = sfd->file->f_op->mmap(sfd->file, vma);
+	if (ret != 0)
+		return ret;
+	sfd->vm_ops = vma->vm_ops;
+#ifdef CONFIG_MMU
+	BUG_ON(!sfd->vm_ops->fault);
+#endif
+	vma->vm_ops = &shm_vm_ops;
+	shm_open(vma);
+
+	return ret;
+}
+
+static int shm_release(struct inode *ino, struct file *file)
+{
+	struct shm_file_data *sfd = shm_file_data(file);
+
+	put_ipc_ns(sfd->ns);
+	shm_file_data(file) = NULL;
+	kfree(sfd);
+	return 0;
+}
+
+static int shm_fsync(struct file *file, int datasync)
+{
+	struct shm_file_data *sfd = shm_file_data(file);
+
+	if (!sfd->file->f_op->fsync)
+		return -EINVAL;
+	return sfd->file->f_op->fsync(sfd->file, datasync);
+}
+
+static unsigned long shm_get_unmapped_area(struct file *file,
+	unsigned long addr, unsigned long len, unsigned long pgoff,
+	unsigned long flags)
+{
+	struct shm_file_data *sfd = shm_file_data(file);
+	return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
+						pgoff, flags);
+}
+
+static const struct file_operations shm_file_operations = {
+	.mmap		= shm_mmap,
+	.fsync		= shm_fsync,
+	.release	= shm_release,
+#ifndef CONFIG_MMU
+	.get_unmapped_area	= shm_get_unmapped_area,
+#endif
+	.llseek		= noop_llseek,
+};
+
+static const struct file_operations shm_file_operations_huge = {
+	.mmap		= shm_mmap,
+	.fsync		= shm_fsync,
+	.release	= shm_release,
+	.get_unmapped_area	= shm_get_unmapped_area,
+	.llseek		= noop_llseek,
+};
+
+int is_file_shm_hugepages(struct file *file)
+{
+	return file->f_op == &shm_file_operations_huge;
+}
+
+static const 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 */
+	.fault	= shm_fault,
+#if defined(CONFIG_NUMA)
+	.set_policy = shm_set_policy,
+	.get_policy = shm_get_policy,
+#endif
+};
+
+/**
+ * newseg - Create a new shared memory segment
+ * @ns: namespace
+ * @params: ptr to the structure that contains key, size and shmflg
+ *
+ * Called with shm_ids.rw_mutex held as a writer.
+ */
+
+static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
+{
+	key_t key = params->key;
+	int shmflg = params->flg;
+	size_t size = params->u.size;
+	int error;
+	struct shmid_kernel *shp;
+	int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
+	struct file * file;
+	char name[13];
+	int id;
+	vm_flags_t acctflag = 0;
+
+	if (size < SHMMIN || size > ns->shm_ctlmax)
+		return -EINVAL;
+
+	if (ns->shm_tot + numpages > ns->shm_ctlall)
+		return -ENOSPC;
+
+	shp = ipc_rcu_alloc(sizeof(*shp));
+	if (!shp)
+		return -ENOMEM;
+
+	shp->shm_perm.key = key;
+	shp->shm_perm.mode = (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;
+	}
+
+	sprintf (name, "SYSV%08x", key);
+	if (shmflg & SHM_HUGETLB) {
+		/* hugetlb_file_setup applies strict accounting */
+		if (shmflg & SHM_NORESERVE)
+			acctflag = VM_NORESERVE;
+		file = hugetlb_file_setup(name, size, acctflag,
+					&shp->mlock_user, HUGETLB_SHMFS_INODE);
+	} else {
+		/*
+		 * Do not allow no accounting for OVERCOMMIT_NEVER, even
+	 	 * if it's asked for.
+		 */
+		if  ((shmflg & SHM_NORESERVE) &&
+				sysctl_overcommit_memory != OVERCOMMIT_NEVER)
+			acctflag = VM_NORESERVE;
+		file = shmem_file_setup(name, size, acctflag);
+	}
+	error = PTR_ERR(file);
+	if (IS_ERR(file))
+		goto no_file;
+
+	id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
+	if (id < 0) {
+		error = id;
+		goto no_id;
+	}
+
+	shp->shm_cprid = task_tgid_vnr(current);
+	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->shm_file = file;
+	/*
+	 * shmid gets reported as "inode#" in /proc/pid/maps.
+	 * proc-ps tools use this. Changing this will break them.
+	 */
+	file->f_dentry->d_inode->i_ino = shp->shm_perm.id;
+
+	ns->shm_tot += numpages;
+	error = shp->shm_perm.id;
+	shm_unlock(shp);
+	return error;
+
+no_id:
+	if (is_file_hugepages(file) && shp->mlock_user)
+		user_shm_unlock(size, shp->mlock_user);
+	fput(file);
+no_file:
+	security_shm_free(shp);
+	ipc_rcu_putref(shp);
+	return error;
+}
+
+/*
+ * Called with shm_ids.rw_mutex and ipcp locked.
+ */
+static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
+{
+	struct shmid_kernel *shp;
+
+	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+	return security_shm_associate(shp, shmflg);
+}
+
+/*
+ * Called with shm_ids.rw_mutex and ipcp locked.
+ */
+static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
+				struct ipc_params *params)
+{
+	struct shmid_kernel *shp;
+
+	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+	if (shp->shm_segsz < params->u.size)
+		return -EINVAL;
+
+	return 0;
+}
+
+SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
+{
+	struct ipc_namespace *ns;
+	struct ipc_ops shm_ops;
+	struct ipc_params shm_params;
+
+	ns = current->nsproxy->ipc_ns;
+
+	shm_ops.getnew = newseg;
+	shm_ops.associate = shm_security;
+	shm_ops.more_checks = shm_more_checks;
+
+	shm_params.key = key;
+	shm_params.flg = shmflg;
+	shm_params.u.size = size;
+
+	return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
+}
+
+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;
+
+		memset(&out, 0, sizeof(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;
+	}
+}
+
+static inline unsigned long
+copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
+{
+	switch(version) {
+	case IPC_64:
+		if (copy_from_user(out, buf, sizeof(*out)))
+			return -EFAULT;
+		return 0;
+	case IPC_OLD:
+	    {
+		struct shmid_ds tbuf_old;
+
+		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
+			return -EFAULT;
+
+		out->shm_perm.uid	= tbuf_old.shm_perm.uid;
+		out->shm_perm.gid	= tbuf_old.shm_perm.gid;
+		out->shm_perm.mode	= tbuf_old.shm_perm.mode;
+
+		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;
+	}
+}
+
+/*
+ * Calculate and add used RSS and swap pages of a shm.
+ * Called with shm_ids.rw_mutex held as a reader
+ */
+static void shm_add_rss_swap(struct shmid_kernel *shp,
+	unsigned long *rss_add, unsigned long *swp_add)
+{
+	struct inode *inode;
+
+	inode = shp->shm_file->f_path.dentry->d_inode;
+
+	if (is_file_hugepages(shp->shm_file)) {
+		struct address_space *mapping = inode->i_mapping;
+		struct hstate *h = hstate_file(shp->shm_file);
+		*rss_add += pages_per_huge_page(h) * mapping->nrpages;
+	} else {
+#ifdef CONFIG_SHMEM
+		struct shmem_inode_info *info = SHMEM_I(inode);
+		spin_lock(&info->lock);
+		*rss_add += inode->i_mapping->nrpages;
+		*swp_add += info->swapped;
+		spin_unlock(&info->lock);
+#else
+		*rss_add += inode->i_mapping->nrpages;
+#endif
+	}
+}
+
+/*
+ * Called with shm_ids.rw_mutex held as a reader
+ */
+static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
+		unsigned long *swp)
+{
+	int next_id;
+	int total, in_use;
+
+	*rss = 0;
+	*swp = 0;
+
+	in_use = shm_ids(ns).in_use;
+
+	for (total = 0, next_id = 0; total < in_use; next_id++) {
+		struct kern_ipc_perm *ipc;
+		struct shmid_kernel *shp;
+
+		ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
+		if (ipc == NULL)
+			continue;
+		shp = container_of(ipc, struct shmid_kernel, shm_perm);
+
+		shm_add_rss_swap(shp, rss, swp);
+
+		total++;
+	}
+}
+
+/*
+ * This function handles some shmctl commands which require the rw_mutex
+ * to be held in write mode.
+ * NOTE: no locks must be held, the rw_mutex is taken inside this function.
+ */
+static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
+		       struct shmid_ds __user *buf, int version)
+{
+	struct kern_ipc_perm *ipcp;
+	struct shmid64_ds shmid64;
+	struct shmid_kernel *shp;
+	int err;
+
+	if (cmd == IPC_SET) {
+		if (copy_shmid_from_user(&shmid64, buf, version))
+			return -EFAULT;
+	}
+
+	ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, cmd,
+			       &shmid64.shm_perm, 0);
+	if (IS_ERR(ipcp))
+		return PTR_ERR(ipcp);
+
+	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+	err = security_shm_shmctl(shp, cmd);
+	if (err)
+		goto out_unlock;
+	switch (cmd) {
+	case IPC_RMID:
+		do_shm_rmid(ns, ipcp);
+		goto out_up;
+	case IPC_SET:
+		ipc_update_perm(&shmid64.shm_perm, ipcp);
+		shp->shm_ctim = get_seconds();
+		break;
+	default:
+		err = -EINVAL;
+	}
+out_unlock:
+	shm_unlock(shp);
+out_up:
+	up_write(&shm_ids(ns).rw_mutex);
+	return err;
+}
+
+SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
+{
+	struct shmid_kernel *shp;
+	int err, version;
+	struct ipc_namespace *ns;
+
+	if (cmd < 0 || shmid < 0) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	version = ipc_parse_version(&cmd);
+	ns = current->nsproxy->ipc_ns;
+
+	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 = ns->shm_ctlmni;
+		shminfo.shmmax = ns->shm_ctlmax;
+		shminfo.shmall = ns->shm_ctlall;
+
+		shminfo.shmmin = SHMMIN;
+		if(copy_shminfo_to_user (buf, &shminfo, version))
+			return -EFAULT;
+
+		down_read(&shm_ids(ns).rw_mutex);
+		err = ipc_get_maxid(&shm_ids(ns));
+		up_read(&shm_ids(ns).rw_mutex);
+
+		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_read(&shm_ids(ns).rw_mutex);
+		shm_info.used_ids = shm_ids(ns).in_use;
+		shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
+		shm_info.shm_tot = ns->shm_tot;
+		shm_info.swap_attempts = 0;
+		shm_info.swap_successes = 0;
+		err = ipc_get_maxid(&shm_ids(ns));
+		up_read(&shm_ids(ns).rw_mutex);
+		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;
+
+		if (cmd == SHM_STAT) {
+			shp = shm_lock(ns, shmid);
+			if (IS_ERR(shp)) {
+				err = PTR_ERR(shp);
+				goto out;
+			}
+			result = shp->shm_perm.id;
+		} else {
+			shp = shm_lock_check(ns, shmid);
+			if (IS_ERR(shp)) {
+				err = PTR_ERR(shp);
+				goto out;
+			}
+			result = 0;
+		}
+		err = -EACCES;
+		if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
+			goto out_unlock;
+		err = security_shm_shmctl(shp, cmd);
+		if (err)
+			goto out_unlock;
+		memset(&tbuf, 0, sizeof(tbuf));
+		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;
+		tbuf.shm_nattch	= shp->shm_nattch;
+		shm_unlock(shp);
+		if(copy_shmid_to_user (buf, &tbuf, version))
+			err = -EFAULT;
+		else
+			err = result;
+		goto out;
+	}
+	case SHM_LOCK:
+	case SHM_UNLOCK:
+	{
+		struct file *uninitialized_var(shm_file);
+
+		lru_add_drain_all();  /* drain pagevecs to lru lists */
+
+		shp = shm_lock_check(ns, shmid);
+		if (IS_ERR(shp)) {
+			err = PTR_ERR(shp);
+			goto out;
+		}
+
+		audit_ipc_obj(&(shp->shm_perm));
+
+		if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
+			uid_t euid = current_euid();
+			err = -EPERM;
+			if (euid != shp->shm_perm.uid &&
+			    euid != shp->shm_perm.cuid)
+				goto out_unlock;
+			if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK))
+				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_perm.mode & SHM_LOCKED)){
+					shp->shm_perm.mode |= 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_perm.mode &= ~SHM_LOCKED;
+			shp->mlock_user = NULL;
+		}
+		shm_unlock(shp);
+		goto out;
+	}
+	case IPC_RMID:
+	case IPC_SET:
+		err = shmctl_down(ns, shmid, cmd, buf, version);
+		return err;
+	default:
+		return -EINVAL;
+	}
+
+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;
+	int acc_mode;
+	unsigned long user_addr;
+	struct ipc_namespace *ns;
+	struct shm_file_data *sfd;
+	struct path path;
+	fmode_t f_mode;
+
+	err = -EINVAL;
+	if (shmid < 0)
+		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
+					goto out;
+		}
+		flags = MAP_SHARED | MAP_FIXED;
+	} else {
+		if ((shmflg & SHM_REMAP))
+			goto out;
+
+		flags = MAP_SHARED;
+	}
+
+	if (shmflg & SHM_RDONLY) {
+		prot = PROT_READ;
+		acc_mode = S_IRUGO;
+		f_mode = FMODE_READ;
+	} else {
+		prot = PROT_READ | PROT_WRITE;
+		acc_mode = S_IRUGO | S_IWUGO;
+		f_mode = FMODE_READ | FMODE_WRITE;
+	}
+	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...
+	 */
+	ns = current->nsproxy->ipc_ns;
+	shp = shm_lock_check(ns, shmid);
+	if (IS_ERR(shp)) {
+		err = PTR_ERR(shp);
+		goto out;
+	}
+
+	err = -EACCES;
+	if (ipcperms(ns, &shp->shm_perm, acc_mode))
+		goto out_unlock;
+
+	err = security_shm_shmat(shp, shmaddr, shmflg);
+	if (err)
+		goto out_unlock;
+
+	path = shp->shm_file->f_path;
+	path_get(&path);
+	shp->shm_nattch++;
+	size = i_size_read(path.dentry->d_inode);
+	shm_unlock(shp);
+
+	err = -ENOMEM;
+	sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
+	if (!sfd)
+		goto out_put_dentry;
+
+	file = alloc_file(&path, f_mode,
+			  is_file_hugepages(shp->shm_file) ?
+				&shm_file_operations_huge :
+				&shm_file_operations);
+	if (!file)
+		goto out_free;
+
+	file->private_data = sfd;
+	file->f_mapping = shp->shm_file->f_mapping;
+	sfd->id = shp->shm_perm.id;
+	sfd->ns = get_ipc_ns(ns);
+	sfd->file = shp->shm_file;
+	sfd->vm_ops = NULL;
+
+	down_write(&current->mm->mmap_sem);
+	if (addr && !(shmflg & SHM_REMAP)) {
+		err = -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 = do_mmap (file, addr, size, prot, flags, 0);
+	*raddr = user_addr;
+	err = 0;
+	if (IS_ERR_VALUE(user_addr))
+		err = (long)user_addr;
+invalid:
+	up_write(&current->mm->mmap_sem);
+
+	fput(file);
+
+out_nattch:
+	down_write(&shm_ids(ns).rw_mutex);
+	shp = shm_lock(ns, shmid);
+	BUG_ON(IS_ERR(shp));
+	shp->shm_nattch--;
+	if(shp->shm_nattch == 0 &&
+	   shp->shm_perm.mode & SHM_DEST)
+		shm_destroy(ns, shp);
+	else
+		shm_unlock(shp);
+	up_write(&shm_ids(ns).rw_mutex);
+
+out:
+	return err;
+
+out_unlock:
+	shm_unlock(shp);
+	goto out;
+
+out_free:
+	kfree(sfd);
+out_put_dentry:
+	path_put(&path);
+	goto out_nattch;
+}
+
+SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
+{
+	unsigned long ret;
+	long err;
+
+	err = do_shmat(shmid, shmaddr, shmflg, &ret);
+	if (err)
+		return err;
+	force_successful_syscall_return();
+	return (long)ret;
+}
+
+/*
+ * detach and kill segment if marked destroyed.
+ * The work is done in shm_close.
+ */
+SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
+{
+	struct mm_struct *mm = current->mm;
+	struct vm_area_struct *vma;
+	unsigned long addr = (unsigned long)shmaddr;
+	int retval = -EINVAL;
+#ifdef CONFIG_MMU
+	loff_t size = 0;
+	struct vm_area_struct *next;
+#endif
+
+	if (addr & ~PAGE_MASK)
+		return retval;
+
+	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);
+
+#ifdef CONFIG_MMU
+	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) &&
+			(vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
+
+
+			size = vma->vm_file->f_path.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 comparisons vs. equal-width types.
+	 */
+	size = PAGE_ALIGN(size);
+	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) &&
+			(vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
+
+			do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+		vma = next;
+	}
+
+#else /* CONFIG_MMU */
+	/* under NOMMU conditions, the exact address to be destroyed must be
+	 * given */
+	retval = -EINVAL;
+	if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
+		do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+		retval = 0;
+	}
+
+#endif
+
+	up_write(&mm->mmap_sem);
+	return retval;
+}
+
+#ifdef CONFIG_PROC_FS
+static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
+{
+	struct shmid_kernel *shp = it;
+	unsigned long rss = 0, swp = 0;
+
+	shm_add_rss_swap(shp, &rss, &swp);
+
+#if BITS_PER_LONG <= 32
+#define SIZE_SPEC "%10lu"
+#else
+#define SIZE_SPEC "%21lu"
+#endif
+
+	return seq_printf(s,
+			  "%10d %10d  %4o " SIZE_SPEC " %5u %5u  "
+			  "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
+			  SIZE_SPEC " " SIZE_SPEC "\n",
+			  shp->shm_perm.key,
+			  shp->shm_perm.id,
+			  shp->shm_perm.mode,
+			  shp->shm_segsz,
+			  shp->shm_cprid,
+			  shp->shm_lprid,
+			  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,
+			  rss * PAGE_SIZE,
+			  swp * PAGE_SIZE);
+}
+#endif