1 files changed, 57 insertions, 44 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 9c042f901570..6067e429f281 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -132,6 +132,14 @@ void __put_task_struct(struct task_struct *tsk)
                 free_task(tsk);
 }
 
+/*
+ * macro override instead of weak attribute alias, to workaround
+ * gcc 4.1.0 and 4.1.1 bugs with weak attribute and empty functions.
+ */
+#ifndef arch_task_cache_init
+#define arch_task_cache_init()
+#endif
+
 void __init fork_init(unsigned long mempages)
 {
 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
@@ -144,6 +152,9 @@ void __init fork_init(unsigned long mempages)
                         ARCH_MIN_TASKALIGN, SLAB_PANIC, NULL);
 #endif
 
+        /* do the arch specific task caches init */
+        arch_task_cache_init();
+
         /*
          * The default maximum number of threads is set to a safe
          * value: the thread structures can take up at most half
@@ -163,6 +174,13 @@ void __init fork_init(unsigned long mempages)
                 init_task.signal->rlim[RLIMIT_NPROC];
 }
 
+int __attribute__((weak)) arch_dup_task_struct(struct task_struct *dst,
+                                               struct task_struct *src)
+{
+        *dst = *src;
+        return 0;
+}
+
 static struct task_struct *dup_task_struct(struct task_struct *orig)
 {
         struct task_struct *tsk;
@@ -181,15 +199,15 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
                 return NULL;
         }
 
-        *tsk = *orig;
+        err = arch_dup_task_struct(tsk, orig);
+        if (err)
+                goto out;
+
         tsk->stack = ti;
 
         err = prop_local_init_single(&tsk->dirties);
-        if (err) {
-                free_thread_info(ti);
-                free_task_struct(tsk);
-                return NULL;
-        }
+        if (err)
+                goto out;
 
         setup_thread_stack(tsk, orig);
 
@@ -205,6 +223,11 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
 #endif
         tsk->splice_pipe = NULL;
         return tsk;
+
+out:
+        free_thread_info(ti);
+        free_task_struct(tsk);
+        return NULL;
 }
 
 #ifdef CONFIG_MMU
@@ -256,7 +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;
@@ -498,7 +521,7 @@ 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;
@@ -782,12 +805,6 @@ 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;
@@ -823,34 +840,6 @@ 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;
@@ -1127,7 +1116,7 @@ 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;
@@ -1385,7 +1374,7 @@ 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);
@@ -1788,3 +1777,27 @@ 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;
+}