Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[sfrench/cifs-2.6.git] / kernel / fork.c
index 89fe414645e9b76aa777a0de7b5e9d6777814a0f..2bb675af4de30908b2dd1a22e745541e2bcbc3f5 100644 (file)
@@ -279,7 +279,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
                if (!tmp)
                        goto fail_nomem;
                *tmp = *mpnt;
-               pol = mpol_copy(vma_policy(mpnt));
+               pol = mpol_dup(vma_policy(mpnt));
                retval = PTR_ERR(pol);
                if (IS_ERR(pol))
                        goto fail_nomem_policy;
@@ -381,14 +381,13 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
        mm->ioctx_list = NULL;
        mm->free_area_cache = TASK_UNMAPPED_BASE;
        mm->cached_hole_size = ~0UL;
-       mm_init_cgroup(mm, p);
+       mm_init_owner(mm, p);
 
        if (likely(!mm_alloc_pgd(mm))) {
                mm->def_flags = 0;
                return mm;
        }
 
-       mm_free_cgroup(mm);
        free_mm(mm);
        return NULL;
 }
@@ -432,13 +431,13 @@ void mmput(struct mm_struct *mm)
        if (atomic_dec_and_test(&mm->mm_users)) {
                exit_aio(mm);
                exit_mmap(mm);
+               set_mm_exe_file(mm, NULL);
                if (!list_empty(&mm->mmlist)) {
                        spin_lock(&mmlist_lock);
                        list_del(&mm->mmlist);
                        spin_unlock(&mmlist_lock);
                }
                put_swap_token(mm);
-               mm_free_cgroup(mm);
                mmdrop(mm);
        }
 }
@@ -521,7 +520,7 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
  * Allocate a new mm structure and copy contents from the
  * mm structure of the passed in task structure.
  */
-static struct mm_struct *dup_mm(struct task_struct *tsk)
+struct mm_struct *dup_mm(struct task_struct *tsk)
 {
        struct mm_struct *mm, *oldmm = current->mm;
        int err;
@@ -545,6 +544,8 @@ static struct mm_struct *dup_mm(struct task_struct *tsk)
        if (init_new_context(tsk, mm))
                goto fail_nocontext;
 
+       dup_mm_exe_file(oldmm, mm);
+
        err = dup_mmap(mm, oldmm);
        if (err)
                goto free_pt;
@@ -805,12 +806,6 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
                goto out;
        }
 
-       /*
-        * Note: we may be using current for both targets (See exec.c)
-        * This works because we cache current->files (old) as oldf. Don't
-        * break this.
-        */
-       tsk->files = NULL;
        newf = dup_fd(oldf, &error);
        if (!newf)
                goto out;
@@ -846,34 +841,6 @@ static int copy_io(unsigned long clone_flags, struct task_struct *tsk)
        return 0;
 }
 
-/*
- *     Helper to unshare the files of the current task.
- *     We don't want to expose copy_files internals to
- *     the exec layer of the kernel.
- */
-
-int unshare_files(void)
-{
-       struct files_struct *files  = current->files;
-       int rc;
-
-       BUG_ON(!files);
-
-       /* This can race but the race causes us to copy when we don't
-          need to and drop the copy */
-       if(atomic_read(&files->count) == 1)
-       {
-               atomic_inc(&files->count);
-               return 0;
-       }
-       rc = copy_files(0, current);
-       if(rc)
-               current->files = files;
-       return rc;
-}
-
-EXPORT_SYMBOL(unshare_files);
-
 static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)
 {
        struct sighand_struct *sig;
@@ -925,7 +892,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
        sig->group_exit_code = 0;
        sig->group_exit_task = NULL;
        sig->group_stop_count = 0;
-       sig->curr_target = NULL;
+       sig->curr_target = tsk;
        init_sigpending(&sig->shared_pending);
        INIT_LIST_HEAD(&sig->posix_timers);
 
@@ -1016,6 +983,13 @@ static void rt_mutex_init_task(struct task_struct *p)
 #endif
 }
 
+#ifdef CONFIG_MM_OWNER
+void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
+{
+       mm->owner = p;
+}
+#endif /* CONFIG_MM_OWNER */
+
 /*
  * This creates a new process as a copy of the old one,
  * but does not actually start it yet.
@@ -1150,7 +1124,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        p->audit_context = NULL;
        cgroup_fork(p);
 #ifdef CONFIG_NUMA
-       p->mempolicy = mpol_copy(p->mempolicy);
+       p->mempolicy = mpol_dup(p->mempolicy);
        if (IS_ERR(p->mempolicy)) {
                retval = PTR_ERR(p->mempolicy);
                p->mempolicy = NULL;
@@ -1408,7 +1382,7 @@ bad_fork_cleanup_security:
        security_task_free(p);
 bad_fork_cleanup_policy:
 #ifdef CONFIG_NUMA
-       mpol_free(p->mempolicy);
+       mpol_put(p->mempolicy);
 bad_fork_cleanup_cgroup:
 #endif
        cgroup_exit(p, cgroup_callbacks_done);
@@ -1697,18 +1671,6 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp
        return 0;
 }
 
-/*
- * Unsharing of semundo for tasks created with CLONE_SYSVSEM is not
- * supported yet
- */
-static int unshare_semundo(unsigned long unshare_flags, struct sem_undo_list **new_ulistp)
-{
-       if (unshare_flags & CLONE_SYSVSEM)
-               return -EINVAL;
-
-       return 0;
-}
-
 /*
  * unshare allows a process to 'unshare' part of the process
  * context which was originally shared using clone.  copy_*
@@ -1724,8 +1686,8 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
        struct sighand_struct *new_sigh = NULL;
        struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
        struct files_struct *fd, *new_fd = NULL;
-       struct sem_undo_list *new_ulist = NULL;
        struct nsproxy *new_nsproxy = NULL;
+       int do_sysvsem = 0;
 
        check_unshare_flags(&unshare_flags);
 
@@ -1737,6 +1699,13 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
                                CLONE_NEWNET))
                goto bad_unshare_out;
 
+       /*
+        * CLONE_NEWIPC must also detach from the undolist: after switching
+        * to a new ipc namespace, the semaphore arrays from the old
+        * namespace are unreachable.
+        */
+       if (unshare_flags & (CLONE_NEWIPC|CLONE_SYSVSEM))
+               do_sysvsem = 1;
        if ((err = unshare_thread(unshare_flags)))
                goto bad_unshare_out;
        if ((err = unshare_fs(unshare_flags, &new_fs)))
@@ -1747,13 +1716,17 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
                goto bad_unshare_cleanup_sigh;
        if ((err = unshare_fd(unshare_flags, &new_fd)))
                goto bad_unshare_cleanup_vm;
-       if ((err = unshare_semundo(unshare_flags, &new_ulist)))
-               goto bad_unshare_cleanup_fd;
        if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy,
                        new_fs)))
-               goto bad_unshare_cleanup_semundo;
+               goto bad_unshare_cleanup_fd;
 
-       if (new_fs ||  new_mm || new_fd || new_ulist || new_nsproxy) {
+       if (new_fs ||  new_mm || new_fd || do_sysvsem || new_nsproxy) {
+               if (do_sysvsem) {
+                       /*
+                        * CLONE_SYSVSEM is equivalent to sys_exit().
+                        */
+                       exit_sem(current);
+               }
 
                if (new_nsproxy) {
                        switch_task_namespaces(current, new_nsproxy);
@@ -1789,7 +1762,6 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
        if (new_nsproxy)
                put_nsproxy(new_nsproxy);
 
-bad_unshare_cleanup_semundo:
 bad_unshare_cleanup_fd:
        if (new_fd)
                put_files_struct(new_fd);
@@ -1811,3 +1783,27 @@ bad_unshare_cleanup_thread:
 bad_unshare_out:
        return err;
 }
+
+/*
+ *     Helper to unshare the files of the current task.
+ *     We don't want to expose copy_files internals to
+ *     the exec layer of the kernel.
+ */
+
+int unshare_files(struct files_struct **displaced)
+{
+       struct task_struct *task = current;
+       struct files_struct *copy = NULL;
+       int error;
+
+       error = unshare_fd(CLONE_FILES, &copy);
+       if (error || !copy) {
+               *displaced = NULL;
+               return error;
+       }
+       *displaced = task->files;
+       task_lock(task);
+       task->files = copy;
+       task_unlock(task);
+       return 0;
+}