1 files changed, 40 insertions, 39 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index fbd3497b221..1380d8ace33 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -374,12 +374,11 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 	 */
 	down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
 
-	mm->locked_vm = 0;
-	mm->mmap = NULL;
-	mm->vmacache_seqnum = 0;
-	mm->map_count = 0;
-	cpumask_clear(mm_cpumask(mm));
-	mm->mm_rb = RB_ROOT;
+	mm->total_vm = oldmm->total_vm;
+	mm->shared_vm = oldmm->shared_vm;
+	mm->exec_vm = oldmm->exec_vm;
+	mm->stack_vm = oldmm->stack_vm;
+
 	rb_link = &mm->mm_rb.rb_node;
 	rb_parent = NULL;
 	pprev = &mm->mmap;
@@ -430,7 +429,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 				atomic_dec(&inode->i_writecount);
 			mutex_lock(&mapping->i_mmap_mutex);
 			if (tmp->vm_flags & VM_SHARED)
-				mapping->i_mmap_writable++;
+				atomic_inc(&mapping->i_mmap_writable);
 			flush_dcache_mmap_lock(mapping);
 			/* insert tmp into the share list, just after mpnt */
 			if (unlikely(tmp->vm_flags & VM_NONLINEAR))
@@ -536,19 +535,37 @@ static void mm_init_aio(struct mm_struct *mm)
 #endif
 }
 
+static void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
+{
+#ifdef CONFIG_MEMCG
+	mm->owner = p;
+#endif
+}
+
 static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
 {
+	mm->mmap = NULL;
+	mm->mm_rb = RB_ROOT;
+	mm->vmacache_seqnum = 0;
 	atomic_set(&mm->mm_users, 1);
 	atomic_set(&mm->mm_count, 1);
 	init_rwsem(&mm->mmap_sem);
 	INIT_LIST_HEAD(&mm->mmlist);
 	mm->core_state = NULL;
 	atomic_long_set(&mm->nr_ptes, 0);
+	mm->map_count = 0;
+	mm->locked_vm = 0;
+	mm->pinned_vm = 0;
 	memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
 	spin_lock_init(&mm->page_table_lock);
+	mm_init_cpumask(mm);
 	mm_init_aio(mm);
 	mm_init_owner(mm, p);
+	mmu_notifier_mm_init(mm);
 	clear_tlb_flush_pending(mm);
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
+	mm->pmd_huge_pte = NULL;
+#endif
 
 	if (current->mm) {
 		mm->flags = current->mm->flags & MMF_INIT_MASK;
@@ -558,11 +575,17 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
 		mm->def_flags = 0;
 	}
 
-	if (likely(!mm_alloc_pgd(mm))) {
-		mmu_notifier_mm_init(mm);
-		return mm;
-	}
+	if (mm_alloc_pgd(mm))
+		goto fail_nopgd;
+
+	if (init_new_context(p, mm))
+		goto fail_nocontext;
+
+	return mm;
 
+fail_nocontext:
+	mm_free_pgd(mm);
+fail_nopgd:
 	free_mm(mm);
 	return NULL;
 }
@@ -596,7 +619,6 @@ struct mm_struct *mm_alloc(void)
 		return NULL;
 
 	memset(mm, 0, sizeof(*mm));
-	mm_init_cpumask(mm);
 	return mm_init(mm, current);
 }
 
@@ -828,17 +850,10 @@ static struct mm_struct *dup_mm(struct task_struct *tsk)
 		goto fail_nomem;
 
 	memcpy(mm, oldmm, sizeof(*mm));
-	mm_init_cpumask(mm);
 
-#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
-	mm->pmd_huge_pte = NULL;
-#endif
 	if (!mm_init(mm, tsk))
 		goto fail_nomem;
 
-	if (init_new_context(tsk, mm))
-		goto fail_nocontext;
-
 	dup_mm_exe_file(oldmm, mm);
 
 	err = dup_mmap(mm, oldmm);
@@ -860,15 +875,6 @@ free_pt:
 
 fail_nomem:
 	return NULL;
-
-fail_nocontext:
-	/*
-	 * If init_new_context() failed, we cannot use mmput() to free the mm
-	 * because it calls destroy_context()
-	 */
-	mm_free_pgd(mm);
-	free_mm(mm);
-	return NULL;
 }
 
 static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
@@ -1140,13 +1146,6 @@ static void rt_mutex_init_task(struct task_struct *p)
 #endif
 }
 
-#ifdef CONFIG_MEMCG
-void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
-{
-	mm->owner = p;
-}
-#endif /* CONFIG_MEMCG */
-
 /*
  * Initialize POSIX timer handling for a single task.
  */
@@ -1346,10 +1345,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #ifdef CONFIG_DEBUG_MUTEXES
 	p->blocked_on = NULL; /* not blocked yet */
 #endif
-#ifdef CONFIG_MEMCG
-	p->memcg_batch.do_batch = 0;
-	p->memcg_batch.memcg = NULL;
-#endif
 #ifdef CONFIG_BCACHE
 	p->sequential_io	= 0;
 	p->sequential_io_avg	= 0;
@@ -1367,6 +1362,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	if (retval)
 		goto bad_fork_cleanup_policy;
 	/* copy all the process information */
+	shm_init_task(p);
 	retval = copy_semundo(clone_flags, p);
 	if (retval)
 		goto bad_fork_cleanup_audit;
@@ -1918,6 +1914,11 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
 			 */
 			exit_sem(current);
 		}
+		if (unshare_flags & CLONE_NEWIPC) {
+			/* Orphan segments in old ns (see sem above). */
+			exit_shm(current);
+			shm_init_task(current);
+		}
 
 		if (new_nsproxy)
 			switch_task_namespaces(current, new_nsproxy);