1 files changed, 42 insertions, 112 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 05b92c457010..e7548dee636b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -40,6 +40,7 @@
 #include <linux/tracehook.h>
 #include <linux/futex.h>
 #include <linux/compat.h>
+#include <linux/kthread.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/rcupdate.h>
 #include <linux/ptrace.h>
@@ -109,20 +110,25 @@ int nr_processes(void)
 }
 
 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
-# define alloc_task_struct()    kmem_cache_alloc(task_struct_cachep, GFP_KERNEL)
-# define free_task_struct(tsk)  kmem_cache_free(task_struct_cachep, (tsk))
+# define alloc_task_struct_node(node)           \
+                kmem_cache_alloc_node(task_struct_cachep, GFP_KERNEL, node)
+# define free_task_struct(tsk)                  \
+                kmem_cache_free(task_struct_cachep, (tsk))
 static struct kmem_cache *task_struct_cachep;
 #endif
 
 #ifndef __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-static inline struct thread_info *alloc_thread_info(struct task_struct *tsk)
+static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
+                                                  int node)
 {
 #ifdef CONFIG_DEBUG_STACK_USAGE
         gfp_t mask = GFP_KERNEL | __GFP_ZERO;
 #else
         gfp_t mask = GFP_KERNEL;
 #endif
-        return (struct thread_info *)__get_free_pages(mask, THREAD_SIZE_ORDER);
+        struct page *page = alloc_pages_node(node, mask, THREAD_SIZE_ORDER);
+
+        return page ? page_address(page) : NULL;
 }
 
 static inline void free_thread_info(struct thread_info *ti)
@@ -249,16 +255,16 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
         struct task_struct *tsk;
         struct thread_info *ti;
         unsigned long *stackend;
-
+        int node = tsk_fork_get_node(orig);
         int err;
 
         prepare_to_copy(orig);
 
-        tsk = alloc_task_struct();
+        tsk = alloc_task_struct_node(node);
         if (!tsk)
                 return NULL;
 
-        ti = alloc_thread_info(tsk);
+        ti = alloc_thread_info_node(tsk, node);
         if (!ti) {
                 free_task_struct(tsk);
                 return NULL;
@@ -1181,12 +1187,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                 pid = alloc_pid(p->nsproxy->pid_ns);
                 if (!pid)
                         goto bad_fork_cleanup_io;
-
-                if (clone_flags & CLONE_NEWPID) {
-                        retval = pid_ns_prepare_proc(p->nsproxy->pid_ns);
-                        if (retval < 0)
-                                goto bad_fork_free_pid;
-                }
         }
 
         p->pid = pid_nr(pid);
@@ -1205,6 +1205,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
          * Clear TID on mm_release()?
          */
         p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
+#ifdef CONFIG_BLOCK
+        p->plug = NULL;
+#endif
 #ifdef CONFIG_FUTEX
         p->robust_list = NULL;
 #ifdef CONFIG_COMPAT
@@ -1290,7 +1293,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                 tracehook_finish_clone(p, clone_flags, trace);
 
                 if (thread_group_leader(p)) {
-                        if (clone_flags & CLONE_NEWPID)
+                        if (is_child_reaper(pid))
                                 p->nsproxy->pid_ns->child_reaper = p;
 
                         p->signal->leader_pid = pid;
@@ -1513,38 +1516,24 @@ void __init proc_caches_init(void)
 }
 
 /*
- * Check constraints on flags passed to the unshare system call and
- * force unsharing of additional process context as appropriate.
+ * Check constraints on flags passed to the unshare system call.
  */
-static void check_unshare_flags(unsigned long *flags_ptr)
+static int check_unshare_flags(unsigned long unshare_flags)
 {
+        if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
+                                CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
+                                CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET))
+                return -EINVAL;
         /*
-         * If unsharing a thread from a thread group, must also
-         * unshare vm.
-         */
-        if (*flags_ptr & CLONE_THREAD)
-                *flags_ptr |= CLONE_VM;
-
-        /*
-         * If unsharing vm, must also unshare signal handlers.
-         */
-        if (*flags_ptr & CLONE_VM)
-                *flags_ptr |= CLONE_SIGHAND;
-
-        /*
-         * If unsharing namespace, must also unshare filesystem information.
+         * Not implemented, but pretend it works if there is nothing to
+         * unshare. Note that unsharing CLONE_THREAD or CLONE_SIGHAND
+         * needs to unshare vm.
          */
-        if (*flags_ptr & CLONE_NEWNS)
-                *flags_ptr |= CLONE_FS;
-}
-
-/*
- * Unsharing of tasks created with CLONE_THREAD is not supported yet
- */
-static int unshare_thread(unsigned long unshare_flags)
-{
-        if (unshare_flags & CLONE_THREAD)
-                return -EINVAL;
+        if (unshare_flags & (CLONE_THREAD | CLONE_SIGHAND | CLONE_VM)) {
+                /* FIXME: get_task_mm() increments ->mm_users */
+                if (atomic_read(&current->mm->mm_users) > 1)
+                        return -EINVAL;
+        }
 
         return 0;
 }
@@ -1571,34 +1560,6 @@ static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
 }
 
 /*
- * Unsharing of sighand is not supported yet
- */
-static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp)
-{
-        struct sighand_struct *sigh = current->sighand;
-
-        if ((unshare_flags & CLONE_SIGHAND) && atomic_read(&sigh->count) > 1)
-                return -EINVAL;
-        else
-                return 0;
-}
-
-/*
- * Unshare vm if it is being shared
- */
-static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp)
-{
-        struct mm_struct *mm = current->mm;
-
-        if ((unshare_flags & CLONE_VM) &&
-            (mm && atomic_read(&mm->mm_users) > 1)) {
-                return -EINVAL;
-        }
-
-        return 0;
-}
-
-/*
  * Unshare file descriptor table if it is being shared
  */
 static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp)
@@ -1626,45 +1587,37 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp
  */
 SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
 {
-        int err = 0;
         struct fs_struct *fs, *new_fs = NULL;
-        struct sighand_struct *new_sigh = NULL;
-        struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
         struct files_struct *fd, *new_fd = NULL;
         struct nsproxy *new_nsproxy = NULL;
         int do_sysvsem = 0;
+        int err;
 
-        check_unshare_flags(&unshare_flags);
-
-        /* Return -EINVAL for all unsupported flags */
-        err = -EINVAL;
-        if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
-                                CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
-                                CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET))
+        err = check_unshare_flags(unshare_flags);
+        if (err)
                 goto bad_unshare_out;
 
         /*
+         * If unsharing namespace, must also unshare filesystem information.
+         */
+        if (unshare_flags & CLONE_NEWNS)
+                unshare_flags |= CLONE_FS;
+        /*
          * 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)))
-                goto bad_unshare_cleanup_thread;
-        if ((err = unshare_sighand(unshare_flags, &new_sigh)))
-                goto bad_unshare_cleanup_fs;
-        if ((err = unshare_vm(unshare_flags, &new_mm)))
-                goto bad_unshare_cleanup_sigh;
+                goto bad_unshare_out;
         if ((err = unshare_fd(unshare_flags, &new_fd)))
-                goto bad_unshare_cleanup_vm;
+                goto bad_unshare_cleanup_fs;
         if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy,
                         new_fs)))
                 goto bad_unshare_cleanup_fd;
 
-        if (new_fs ||  new_mm || new_fd || do_sysvsem || new_nsproxy) {
+        if (new_fs || new_fd || do_sysvsem || new_nsproxy) {
                 if (do_sysvsem) {
                         /*
                          * CLONE_SYSVSEM is equivalent to sys_exit().
@@ -1690,19 +1643,6 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
                         spin_unlock(&fs->lock);
                 }
 
-                if (new_mm) {
-                        mm = current->mm;
-                        active_mm = current->active_mm;
-                        current->mm = new_mm;
-                        current->active_mm = new_mm;
-                        if (current->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
-                                atomic_dec(&mm->oom_disable_count);
-                                atomic_inc(&new_mm->oom_disable_count);
-                        }
-                        activate_mm(active_mm, new_mm);
-                        new_mm = mm;
-                }
-
                 if (new_fd) {
                         fd = current->files;
                         current->files = new_fd;
@@ -1719,20 +1659,10 @@ bad_unshare_cleanup_fd:
         if (new_fd)
                 put_files_struct(new_fd);
 
-bad_unshare_cleanup_vm:
-        if (new_mm)
-                mmput(new_mm);
-
-bad_unshare_cleanup_sigh:
-        if (new_sigh)
-                if (atomic_dec_and_test(&new_sigh->count))
-                        kmem_cache_free(sighand_cachep, new_sigh);
-
 bad_unshare_cleanup_fs:
         if (new_fs)
                 free_fs_struct(new_fs);
 
-bad_unshare_cleanup_thread:
 bad_unshare_out:
         return err;
 }