1 files changed, 25 insertions, 9 deletions

diff --git a/ipc/shm.c b/ipc/shm.c
index 7d86f058fb86..bd2fcc4d454e 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -275,10 +275,8 @@ static inline void shm_rmid(struct shmid_kernel *s)
 }
 
 
-static int __shm_open(struct vm_area_struct *vma)
+static int __shm_open(struct shm_file_data *sfd)
 {
-	struct file *file = vma->vm_file;
-	struct shm_file_data *sfd = shm_file_data(file);
 	struct shmid_kernel *shp;
 
 	shp = shm_lock(sfd->ns, sfd->id);
@@ -302,7 +300,15 @@ static int __shm_open(struct vm_area_struct *vma)
 /* This is called by fork, once for every shm attach. */
 static void shm_open(struct vm_area_struct *vma)
 {
-	int err = __shm_open(vma);
+	struct file *file = vma->vm_file;
+	struct shm_file_data *sfd = shm_file_data(file);
+	int err;
+
+	/* Always call underlying open if present */
+	if (sfd->vm_ops->open)
+		sfd->vm_ops->open(vma);
+
+	err = __shm_open(sfd);
 	/*
 	 * We raced in the idr lookup or with shm_destroy().
 	 * Either way, the ID is busted.
@@ -359,10 +365,8 @@ static bool shm_may_destroy(struct shmid_kernel *shp)
  * The descriptor has already been removed from the current->mm->mmap list
  * and will later be kfree()d.
  */
-static void shm_close(struct vm_area_struct *vma)
+static void __shm_close(struct shm_file_data *sfd)
 {
-	struct file *file = vma->vm_file;
-	struct shm_file_data *sfd = shm_file_data(file);
 	struct shmid_kernel *shp;
 	struct ipc_namespace *ns = sfd->ns;
 
@@ -388,6 +392,18 @@ done:
 	up_write(&shm_ids(ns).rwsem);
 }
 
+static void shm_close(struct vm_area_struct *vma)
+{
+	struct file *file = vma->vm_file;
+	struct shm_file_data *sfd = shm_file_data(file);
+
+	/* Always call underlying close if present */
+	if (sfd->vm_ops->close)
+		sfd->vm_ops->close(vma);
+
+	__shm_close(sfd);
+}
+
 /* Called with ns->shm_ids(ns).rwsem locked */
 static int shm_try_destroy_orphaned(int id, void *p, void *data)
 {
@@ -583,13 +599,13 @@ static int shm_mmap(struct file *file, struct vm_area_struct *vma)
 	 * IPC ID that was removed, and possibly even reused by another shm
 	 * segment already.  Propagate this case as an error to caller.
 	 */
-	ret = __shm_open(vma);
+	ret = __shm_open(sfd);
 	if (ret)
 		return ret;
 
 	ret = call_mmap(sfd->file, vma);
 	if (ret) {
-		shm_close(vma);
+		__shm_close(sfd);
 		return ret;
 	}
 	sfd->vm_ops = vma->vm_ops;