Linux-2.6.12-rc2v2.6.12-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!

1 files changed, 917 insertions, 0 deletions

diff --git a/ipc/shm.c b/ipc/shm.c
new file mode 100644
index 000000000000..06cd5c91056f
--- /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