ipc: use simple_read_from_buffer()
[linux-2.6.git] / ipc / shm.c
index 07f4b7a..e77ec69 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -56,13 +56,10 @@ 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_unlock(shp)                        \
        ipc_unlock(&(shp)->shm_perm)
-#define shm_buildid(id, seq)   ipc_buildid(id, seq)
 
 static int newseg(struct ipc_namespace *, struct ipc_params *);
 static void shm_open(struct vm_area_struct *vma);
@@ -72,22 +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 __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);
+       ipc_init_ids(&ns->ids[IPC_SHM_IDS]);
 }
 
 /*
  * 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 shmid_kernel *shp)
+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 */
@@ -98,83 +97,23 @@ 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)
 {
-       struct shmid_kernel *shp;
-       struct kern_ipc_perm *perm;
-       int next_id;
-       int total, in_use;
-
-       down_write(&shm_ids(ns).rw_mutex);
-
-       in_use = shm_ids(ns).in_use;
-
-       for (total = 0, next_id = 0; total < in_use; next_id++) {
-               perm = idr_find(&shm_ids(ns).ipcs_idr, next_id);
-               if (perm == NULL)
-                       continue;
-               ipc_lock_by_ptr(perm);
-               shp = container_of(perm, struct shmid_kernel, shm_perm);
-               do_shm_rmid(ns, shp);
-               total++;
-       }
-       up_write(&shm_ids(ns).rw_mutex);
-
-       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);
 }
 
 /*
- * shm_lock_(check_)down routines are called in the paths where the rw_mutex
- * is held to protect access to the idr tree.
- */
-static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns,
-                                               int id)
-{
-       struct kern_ipc_perm *ipcp = ipc_lock_down(&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_down(
-                                               struct ipc_namespace *ns,
-                                               int id)
-{
-       struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id);
-
-       if (IS_ERR(ipcp))
-               return (struct shmid_kernel *)ipcp;
-
-       return container_of(ipcp, struct shmid_kernel, shm_perm);
-}
-
-/*
  * shm_lock_(check_) routines are called in the paths where the rw_mutex
- * is not held.
+ * is not necessarily held.
  */
 static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
 {
@@ -202,12 +141,6 @@ static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
        ipc_rmid(&shm_ids(ns), &s->shm_perm);
 }
 
-static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
-{
-       return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
-}
-
-
 
 /* This is called by fork, once for every shm attach. */
 static void shm_open(struct vm_area_struct *vma)
@@ -263,7 +196,7 @@ static void shm_close(struct vm_area_struct *vma)
 
        down_write(&shm_ids(ns).rw_mutex);
        /* remove from the list of attaches of the shm segment */
-       shp = shm_lock_down(ns, sfd->id);
+       shp = shm_lock(ns, sfd->id);
        BUG_ON(IS_ERR(shp));
        shp->shm_lprid = task_tgid_vnr(current);
        shp->shm_dtim = get_seconds();
@@ -306,8 +239,7 @@ static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
                pol = sfd->vm_ops->get_policy(vma, addr);
        else if (vma->vm_policy)
                pol = vma->vm_policy;
-       else
-               pol = current->mempolicy;
+
        return pol;
 }
 #endif
@@ -450,7 +382,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
        if (IS_ERR(file))
                goto no_file;
 
-       id = shm_addid(ns, shp);
+       id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
        if (id < 0) {
                error = id;
                goto no_id;
@@ -462,7 +394,6 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
        shp->shm_ctim = get_seconds();
        shp->shm_segsz = size;
        shp->shm_nattch = 0;
-       shp->shm_perm.id = shm_buildid(id, shp->shm_perm.seq);
        shp->shm_file = file;
        /*
         * shmid gets reported as "inode#" in /proc/pid/maps.
@@ -553,28 +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;
@@ -582,9 +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;
            }
@@ -645,7 +562,8 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
 
                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);
@@ -658,9 +576,53 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
        }
 }
 
-asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
+/*
+ * 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)
 {
-       struct shm_setbuf setbuf;
        struct shmid_kernel *shp;
        int err, version;
        struct ipc_namespace *ns;
@@ -817,97 +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.
-                */
-               down_write(&shm_ids(ns).rw_mutex);
-               shp = shm_lock_check_down(ns, shmid);
-               if (IS_ERR(shp)) {
-                       err = PTR_ERR(shp);
-                       goto out_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);
-               up_write(&shm_ids(ns).rw_mutex);
-               goto out;
-       }
-
        case IPC_SET:
-       {
-               if (!buf) {
-                       err = -EFAULT;
-                       goto out;
-               }
-
-               if (copy_shmid_from_user (&setbuf, buf, version)) {
-                       err = -EFAULT;
-                       goto out;
-               }
-               down_write(&shm_ids(ns).rw_mutex);
-               shp = shm_lock_check_down(ns, shmid);
-               if (IS_ERR(shp)) {
-                       err = PTR_ERR(shp);
-                       goto out_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:
-       up_write(&shm_ids(ns).rw_mutex);
-       goto out;
 out_unlock:
        shm_unlock(shp);
 out:
@@ -1002,8 +880,6 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
        if (!sfd)
                goto out_put_dentry;
 
-       err = -ENOMEM;
-
        file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations);
        if (!file)
                goto out_free;
@@ -1041,7 +917,7 @@ invalid:
 
 out_nattch:
        down_write(&shm_ids(ns).rw_mutex);
-       shp = shm_lock_down(ns, shmid);
+       shp = shm_lock(ns, shmid);
        BUG_ON(IS_ERR(shp));
        shp->shm_nattch--;
        if(shp->shm_nattch == 0 &&
@@ -1168,16 +1044,16 @@ 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->shm_perm.id,
                          shp->shm_perm.mode,