ipc: use simple_read_from_buffer()
[linux-2.6.git] / ipc / shm.c
index 02faa54..e77ec69 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
 #include <linux/capability.h>
 #include <linux/ptrace.h>
 #include <linux/seq_file.h>
-#include <linux/mutex.h>
+#include <linux/rwsem.h>
 #include <linux/nsproxy.h>
 #include <linux/mount.h>
+#include <linux/ipc_namespace.h>
 
 #include <asm/uaccess.h>
 
@@ -55,21 +56,12 @@ struct shm_file_data {
 static const struct file_operations shm_file_operations;
 static struct vm_operations_struct shm_vm_ops;
 
-static struct ipc_ids init_shm_ids;
+#define shm_ids(ns)    ((ns)->ids[IPC_SHM_IDS])
 
-#define shm_ids(ns)    (*((ns)->ids[IPC_SHM_IDS]))
-
-#define shm_lock(ns, id)               \
-       ((struct shmid_kernel*)ipc_lock(&shm_ids(ns),id))
 #define shm_unlock(shp)                        \
        ipc_unlock(&(shp)->shm_perm)
-#define shm_get(ns, id)                        \
-       ((struct shmid_kernel*)ipc_get(&shm_ids(ns),id))
-#define shm_buildid(ns, id, seq)       \
-       ipc_buildid(&shm_ids(ns), id, seq)
 
-static int newseg (struct ipc_namespace *ns, key_t key,
-               int shmflg, size_t size);
+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);
@@ -77,18 +69,24 @@ static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
 static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
 #endif
 
-static void __ipc_init __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
+void shm_init_ns(struct ipc_namespace *ns)
 {
-       ns->ids[IPC_SHM_IDS] = ids;
        ns->shm_ctlmax = SHMMAX;
        ns->shm_ctlall = SHMALL;
        ns->shm_ctlmni = SHMMNI;
        ns->shm_tot = 0;
-       ipc_init_ids(ids, 1);
+       ipc_init_ids(&ns->ids[IPC_SHM_IDS]);
 }
 
-static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
+/*
+ * 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 */
@@ -99,67 +97,51 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
 }
 
 #ifdef CONFIG_IPC_NS
-int shm_init_ns(struct ipc_namespace *ns)
-{
-       struct ipc_ids *ids;
-
-       ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
-       if (ids == NULL)
-               return -ENOMEM;
-
-       __shm_init_ns(ns, ids);
-       return 0;
-}
-
 void shm_exit_ns(struct ipc_namespace *ns)
 {
-       int i;
-       struct shmid_kernel *shp;
-
-       mutex_lock(&shm_ids(ns).mutex);
-       for (i = 0; i <= shm_ids(ns).max_id; i++) {
-               shp = shm_lock(ns, i);
-               if (shp == NULL)
-                       continue;
-
-               do_shm_rmid(ns, shp);
-       }
-       mutex_unlock(&shm_ids(ns).mutex);
-
-       ipc_fini_ids(ns->ids[IPC_SHM_IDS]);
-       kfree(ns->ids[IPC_SHM_IDS]);
-       ns->ids[IPC_SHM_IDS] = NULL;
+       free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
 }
 #endif
 
 void __init shm_init (void)
 {
-       __shm_init_ns(&init_ipc_ns, &init_shm_ids);
+       shm_init_ns(&init_ipc_ns);
        ipc_init_proc_interface("sysvipc/shm",
                                "       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime\n",
                                IPC_SHM_IDS, sysvipc_shm_proc_show);
 }
 
-static inline int shm_checkid(struct ipc_namespace *ns,
-               struct shmid_kernel *s, int id)
+/*
+ * 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)
 {
-       if (ipc_checkid(&shm_ids(ns), &s->shm_perm, id))
-               return -EIDRM;
-       return 0;
+       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_rmid(struct ipc_namespace *ns, int id)
+static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns,
+                                               int id)
 {
-       return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), 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 int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
+static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
 {
-       return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
+       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)
 {
@@ -168,9 +150,9 @@ static void shm_open(struct vm_area_struct *vma)
        struct shmid_kernel *shp;
 
        shp = shm_lock(sfd->ns, sfd->id);
-       BUG_ON(!shp);
+       BUG_ON(IS_ERR(shp));
        shp->shm_atim = get_seconds();
-       shp->shm_lprid = current->tgid;
+       shp->shm_lprid = task_tgid_vnr(current);
        shp->shm_nattch++;
        shm_unlock(shp);
 }
@@ -178,15 +160,16 @@ static void shm_open(struct vm_area_struct *vma)
 /*
  * shm_destroy - free the struct shmid_kernel
  *
+ * @ns: namespace
  * @shp: struct to free
  *
- * It has to be called with shp and shm_ids.mutex locked,
+ * 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->id);
+       shm_rmid(ns, shp);
        shm_unlock(shp);
        if (!is_file_hugepages(shp->shm_file))
                shmem_lock(shp->shm_file, 0, shp->mlock_user);
@@ -211,11 +194,11 @@ static void shm_close(struct vm_area_struct *vma)
        struct shmid_kernel *shp;
        struct ipc_namespace *ns = sfd->ns;
 
-       mutex_lock(&shm_ids(ns).mutex);
+       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(!shp);
-       shp->shm_lprid = current->tgid;
+       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 &&
@@ -223,20 +206,19 @@ static void shm_close(struct vm_area_struct *vma)
                shm_destroy(ns, shp);
        else
                shm_unlock(shp);
-       mutex_unlock(&shm_ids(ns).mutex);
+       up_write(&shm_ids(ns).rw_mutex);
 }
 
-static struct page *shm_nopage(struct vm_area_struct *vma,
-                              unsigned long address, int *type)
+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->nopage(vma, address, type);
+       return sfd->vm_ops->fault(vma, vmf);
 }
 
 #ifdef CONFIG_NUMA
-int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
+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);
@@ -246,7 +228,8 @@ int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
        return err;
 }
 
-struct mempolicy *shm_get_policy(struct vm_area_struct *vma, unsigned long addr)
+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);
@@ -254,8 +237,9 @@ struct mempolicy *shm_get_policy(struct vm_area_struct *vma, unsigned long addr)
 
        if (sfd->vm_ops->get_policy)
                pol = sfd->vm_ops->get_policy(vma, addr);
-       else
+       else if (vma->vm_policy)
                pol = vma->vm_policy;
+
        return pol;
 }
 #endif
@@ -269,6 +253,9 @@ static int shm_mmap(struct file * file, struct vm_area_struct * 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);
 
@@ -327,15 +314,26 @@ static const struct file_operations shm_file_operations = {
 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 = shm_nopage,
+       .fault  = shm_fault,
 #if defined(CONFIG_NUMA)
        .set_policy = shm_set_policy,
        .get_policy = shm_get_policy,
 #endif
 };
 
-static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
+/**
+ * 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;
@@ -364,9 +362,10 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
                return error;
        }
 
+       sprintf (name, "SYSV%08x", key);
        if (shmflg & SHM_HUGETLB) {
-               /* hugetlb_zero_setup takes care of mlock user accounting */
-               file = hugetlb_zero_setup(size);
+               /* hugetlb_file_setup takes care of mlock user accounting */
+               file = hugetlb_file_setup(name, size);
                shp->mlock_user = current->user;
        } else {
                int acctflag = VM_ACCOUNT;
@@ -377,35 +376,35 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
                if  ((shmflg & SHM_NORESERVE) &&
                                sysctl_overcommit_memory != OVERCOMMIT_NEVER)
                        acctflag = 0;
-               sprintf (name, "SYSV%08x", key);
                file = shmem_file_setup(name, size, acctflag);
        }
        error = PTR_ERR(file);
        if (IS_ERR(file))
                goto no_file;
 
-       error = -ENOSPC;
-       id = shm_addid(ns, shp);
-       if(id == -1) 
+       id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
+       if (id < 0) {
+               error = id;
                goto no_id;
+       }
 
-       shp->shm_cprid = current->tgid;
+       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->id = shm_buildid(ns, id, shp->shm_perm.seq);
        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->id;
+       file->f_dentry->d_inode->i_ino = shp->shm_perm.id;
 
        ns->shm_tot += numpages;
+       error = shp->shm_perm.id;
        shm_unlock(shp);
-       return shp->id;
+       return error;
 
 no_id:
        fput(file);
@@ -415,42 +414,49 @@ no_file:
        return error;
 }
 
-asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
+/*
+ * 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;
-       int err, id = 0;
+
+       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;
+}
+
+asmlinkage long sys_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;
 
-       mutex_lock(&shm_ids(ns).mutex);
-       if (key == IPC_PRIVATE) {
-               err = newseg(ns, key, shmflg, size);
-       } else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) {
-               if (!(shmflg & IPC_CREAT))
-                       err = -ENOENT;
-               else
-                       err = newseg(ns, key, shmflg, size);
-       } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
-               err = -EEXIST;
-       } else {
-               shp = shm_lock(ns, id);
-               BUG_ON(shp==NULL);
-               if (shp->shm_segsz < size)
-                       err = -EINVAL;
-               else if (ipcperms(&shp->shm_perm, shmflg))
-                       err = -EACCES;
-               else {
-                       int shmid = shm_buildid(ns, id, shp->shm_perm.seq);
-                       err = security_shm_associate(shp, shmflg);
-                       if (!err)
-                               err = shmid;
-               }
-               shm_unlock(shp);
-       }
-       mutex_unlock(&shm_ids(ns).mutex);
+       shm_ops.getnew = newseg;
+       shm_ops.associate = shm_security;
+       shm_ops.more_checks = shm_more_checks;
 
-       return err;
+       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)
@@ -478,28 +484,14 @@ static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_
        }
 }
 
-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)
+static inline unsigned long
+copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
 {
        switch(version) {
        case IPC_64:
-           {
-               struct shmid64_ds tbuf;
-
-               if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
+               if (copy_from_user(out, buf, sizeof(*out)))
                        return -EFAULT;
-
-               out->uid        = tbuf.shm_perm.uid;
-               out->gid        = tbuf.shm_perm.gid;
-               out->mode       = tbuf.shm_perm.mode;
-
                return 0;
-           }
        case IPC_OLD:
            {
                struct shmid_ds tbuf_old;
@@ -507,9 +499,9 @@ static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __
                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_perm.mode;
+               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;
            }
@@ -544,27 +536,34 @@ static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminf
        }
 }
 
+/*
+ * 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 i;
+       int next_id;
+       int total, in_use;
 
        *rss = 0;
        *swp = 0;
 
-       for (i = 0; i <= shm_ids(ns).max_id; i++) {
+       in_use = shm_ids(ns).in_use;
+
+       for (total = 0, next_id = 0; total < in_use; next_id++) {
                struct shmid_kernel *shp;
                struct inode *inode;
 
-               shp = shm_get(ns, i);
-               if(!shp)
+               shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
+               if (shp == NULL)
                        continue;
 
                inode = shp->shm_file->f_path.dentry->d_inode;
 
                if (is_file_hugepages(shp->shm_file)) {
                        struct address_space *mapping = inode->i_mapping;
-                       *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages;
+                       struct hstate *h = hstate_file(shp->shm_file);
+                       *rss += pages_per_huge_page(h) * mapping->nrpages;
                } else {
                        struct shmem_inode_info *info = SHMEM_I(inode);
                        spin_lock(&info->lock);
@@ -572,12 +571,58 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
                        *swp += info->swapped;
                        spin_unlock(&info->lock);
                }
+
+               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(&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;
 }
 
-asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
+asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
 {
-       struct shm_setbuf setbuf;
        struct shmid_kernel *shp;
        int err, version;
        struct ipc_namespace *ns;
@@ -607,8 +652,11 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                shminfo.shmmin = SHMMIN;
                if(copy_shminfo_to_user (buf, &shminfo, version))
                        return -EFAULT;
-               /* reading a integer is always atomic */
-               err= shm_ids(ns).max_id;
+
+               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;
@@ -622,14 +670,14 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                        return err;
 
                memset(&shm_info,0,sizeof(shm_info));
-               mutex_lock(&shm_ids(ns).mutex);
+               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 = shm_ids(ns).max_id;
-               mutex_unlock(&shm_ids(ns).mutex);
+               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;
@@ -643,20 +691,25 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
        {
                struct shmid64_ds tbuf;
                int result;
-               memset(&tbuf, 0, sizeof(tbuf));
-               shp = shm_lock(ns, shmid);
-               if(shp==NULL) {
-                       err = -EINVAL;
+
+               if (!buf) {
+                       err = -EFAULT;
                        goto out;
-               } else if(cmd==SHM_STAT) {
-                       err = -EINVAL;
-                       if (shmid > shm_ids(ns).max_id)
-                               goto out_unlock;
-                       result = shm_buildid(ns, shmid, shp->shm_perm.seq);
+               }
+
+               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 {
-                       err = shm_checkid(ns, shp,shmid);
-                       if(err)
-                               goto out_unlock;
+                       shp = shm_lock_check(ns, shmid);
+                       if (IS_ERR(shp)) {
+                               err = PTR_ERR(shp);
+                               goto out;
+                       }
                        result = 0;
                }
                err=-EACCES;
@@ -665,6 +718,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                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;
@@ -683,14 +737,11 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
        case SHM_LOCK:
        case SHM_UNLOCK:
        {
-               shp = shm_lock(ns, shmid);
-               if(shp==NULL) {
-                       err = -EINVAL;
+               shp = shm_lock_check(ns, shmid);
+               if (IS_ERR(shp)) {
+                       err = PTR_ERR(shp);
                        goto out;
                }
-               err = shm_checkid(ns, shp,shmid);
-               if(err)
-                       goto out_unlock;
 
                err = audit_ipc_obj(&(shp->shm_perm));
                if (err)
@@ -714,7 +765,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                        struct user_struct * user = current->user;
                        if (!is_file_hugepages(shp->shm_file)) {
                                err = shmem_lock(shp->shm_file, 1, user);
-                               if (!err) {
+                               if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){
                                        shp->shm_perm.mode |= SHM_LOCKED;
                                        shp->mlock_user = user;
                                }
@@ -728,96 +779,13 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                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.
-                */
-               mutex_lock(&shm_ids(ns).mutex);
-               shp = shm_lock(ns, shmid);
-               err = -EINVAL;
-               if (shp == NULL) 
-                       goto out_up;
-               err = shm_checkid(ns, shp, shmid);
-               if(err)
-                       goto out_unlock_up;
-
-               err = audit_ipc_obj(&(shp->shm_perm));
-               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;
-
-               do_shm_rmid(ns, shp);
-               mutex_unlock(&shm_ids(ns).mutex);
-               goto out;
-       }
-
        case IPC_SET:
-       {
-               if (copy_shmid_from_user (&setbuf, buf, version)) {
-                       err = -EFAULT;
-                       goto out;
-               }
-               mutex_lock(&shm_ids(ns).mutex);
-               shp = shm_lock(ns, shmid);
-               err=-EINVAL;
-               if(shp==NULL)
-                       goto out_up;
-               err = shm_checkid(ns, shp,shmid);
-               if(err)
-                       goto out_unlock_up;
-               err = audit_ipc_obj(&(shp->shm_perm));
-               if (err)
-                       goto out_unlock_up;
-               err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
-               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_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO)
-                       | (setbuf.mode & S_IRWXUGO);
-               shp->shm_ctim = get_seconds();
-               break;
-       }
-
+               err = shmctl_down(ns, shmid, cmd, buf, version);
+               return err;
        default:
-               err = -EINVAL;
-               goto out;
+               return -EINVAL;
        }
 
-       err = 0;
-out_unlock_up:
-       shm_unlock(shp);
-out_up:
-       mutex_unlock(&shm_ids(ns).mutex);
-       goto out;
 out_unlock:
        shm_unlock(shp);
 out:
@@ -887,13 +855,11 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
         * additional creator id...
         */
        ns = current->nsproxy->ipc_ns;
-       shp = shm_lock(ns, shmid);
-       if(shp == NULL)
+       shp = shm_lock_check(ns, shmid);
+       if (IS_ERR(shp)) {
+               err = PTR_ERR(shp);
                goto out;
-
-       err = shm_checkid(ns, shp,shmid);
-       if (err)
-               goto out_unlock;
+       }
 
        err = -EACCES;
        if (ipcperms(&shp->shm_perm, acc_mode))
@@ -904,7 +870,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
                goto out_unlock;
 
        path.dentry = dget(shp->shm_file->f_path.dentry);
-       path.mnt    = mntget(shp->shm_file->f_path.mnt);
+       path.mnt    = shp->shm_file->f_path.mnt;
        shp->shm_nattch++;
        size = i_size_read(path.dentry->d_inode);
        shm_unlock(shp);
@@ -912,19 +878,15 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
        err = -ENOMEM;
        sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
        if (!sfd)
-               goto out_put_path;
+               goto out_put_dentry;
 
-       err = -ENOMEM;
-       file = get_empty_filp();
+       file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations);
        if (!file)
                goto out_free;
 
-       file->f_op = &shm_file_operations;
        file->private_data = sfd;
-       file->f_path = path;
        file->f_mapping = shp->shm_file->f_mapping;
-       file->f_mode = f_mode;
-       sfd->id = shp->id;
+       sfd->id = shp->shm_perm.id;
        sfd->ns = get_ipc_ns(ns);
        sfd->file = shp->shm_file;
        sfd->vm_ops = NULL;
@@ -954,16 +916,16 @@ invalid:
        fput(file);
 
 out_nattch:
-       mutex_lock(&shm_ids(ns).mutex);
+       down_write(&shm_ids(ns).rw_mutex);
        shp = shm_lock(ns, shmid);
-       BUG_ON(!shp);
+       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);
-       mutex_unlock(&shm_ids(ns).mutex);
+       up_write(&shm_ids(ns).rw_mutex);
 
 out:
        return err;
@@ -974,9 +936,8 @@ out_unlock:
 
 out_free:
        kfree(sfd);
-out_put_path:
+out_put_dentry:
        dput(path.dentry);
-       mntput(path.mnt);
        goto out_nattch;
 }
 
@@ -1083,18 +1044,18 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
 static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
 {
        struct shmid_kernel *shp = it;
-       char *format;
 
-#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"
+#if BITS_PER_LONG <= 32
+#define SIZE_SPEC "%10lu"
+#else
+#define SIZE_SPEC "%21lu"
+#endif
 
-       if (sizeof(size_t) <= sizeof(int))
-               format = SMALL_STRING;
-       else
-               format = BIG_STRING;
-       return seq_printf(s, format,
+       return seq_printf(s,
+                         "%10d %10d  %4o " SIZE_SPEC " %5u %5u  "
+                         "%5lu %5u %5u %5u %5u %10lu %10lu %10lu\n",
                          shp->shm_perm.key,
-                         shp->id,
+                         shp->shm_perm.id,
                          shp->shm_perm.mode,
                          shp->shm_segsz,
                          shp->shm_cprid,