Merge branch 'next' into for-linus

Prepare first round of input updates for 3.20.

1 files changed, 17 insertions, 8 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index a91e47d86de2..4dc2ddade9f1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -294,11 +294,18 @@ int __weak arch_dup_task_struct(struct task_struct *dst,
         return 0;
 }
 
+void set_task_stack_end_magic(struct task_struct *tsk)
+{
+        unsigned long *stackend;
+
+        stackend = end_of_stack(tsk);
+        *stackend = STACK_END_MAGIC;    /* for overflow detection */
+}
+
 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;
 
@@ -328,8 +335,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
         setup_thread_stack(tsk, orig);
         clear_user_return_notifier(tsk);
         clear_tsk_need_resched(tsk);
-        stackend = end_of_stack(tsk);
-        *stackend = STACK_END_MAGIC;    /* for overflow detection */
+        set_task_stack_end_magic(tsk);
 
 #ifdef CONFIG_CC_STACKPROTECTOR
         tsk->stack_canary = get_random_int();
@@ -427,7 +433,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
                         get_file(file);
                         if (tmp->vm_flags & VM_DENYWRITE)
                                 atomic_dec(&inode->i_writecount);
-                        mutex_lock(&mapping->i_mmap_mutex);
+                        i_mmap_lock_write(mapping);
                         if (tmp->vm_flags & VM_SHARED)
                                 atomic_inc(&mapping->i_mmap_writable);
                         flush_dcache_mmap_lock(mapping);
@@ -439,7 +445,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
                                 vma_interval_tree_insert_after(tmp, mpnt,
                                                         &mapping->i_mmap);
                         flush_dcache_mmap_unlock(mapping);
-                        mutex_unlock(&mapping->i_mmap_mutex);
+                        i_mmap_unlock_write(mapping);
                 }
 
                 /*
@@ -601,9 +607,8 @@ static void check_mm(struct mm_struct *mm)
                         printk(KERN_ALERT "BUG: Bad rss-counter state "
                                           "mm:%p idx:%d val:%ld\n", mm, i, x);
         }
-
 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
-        VM_BUG_ON(mm->pmd_huge_pte);
+        VM_BUG_ON_MM(mm->pmd_huge_pte, mm);
 #endif
 }
 
@@ -1017,11 +1022,14 @@ void __cleanup_sighand(struct sighand_struct *sighand)
 {
         if (atomic_dec_and_test(&sighand->count)) {
                 signalfd_cleanup(sighand);
+                /*
+                 * sighand_cachep is SLAB_DESTROY_BY_RCU so we can free it
+                 * without an RCU grace period, see __lock_task_sighand().
+                 */
                 kmem_cache_free(sighand_cachep, sighand);
         }
 }
 
-
 /*
  * Initialize POSIX timer handling for a thread group.
  */
@@ -1068,6 +1076,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
         sig->curr_target = tsk;
         init_sigpending(&sig->shared_pending);
         INIT_LIST_HEAD(&sig->posix_timers);
+        seqlock_init(&sig->stats_lock);
 
         hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
         sig->real_timer.function = it_real_fn;