mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/entry/vdso/vma.c

@@ -144,7 +144,7 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
 	struct mm_struct *mm = task->mm;
 	struct vm_area_struct *vma;
 
-	if (down_write_killable(&mm->mmap_sem))
+	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
@@ -154,7 +154,7 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
 			zap_page_range(vma, vma->vm_start, size);
 	}
 
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	return 0;
 }
 #else
@@ -268,7 +268,7 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr)
 	unsigned long text_start;
 	int ret = 0;
 
-	if (down_write_killable(&mm->mmap_sem))
+	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
 	addr = get_unmapped_area(NULL, addr,
@@ -311,7 +311,7 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr)
 	}
 
 up_fail:
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	return ret;
 }
 
@@ -373,7 +373,7 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 
-	down_write(&mm->mmap_sem);
+	mmap_write_lock(mm);
 	/*
 	 * Check if we have already mapped vdso blob - fail to prevent
 	 * abusing from userspace install_speciall_mapping, which may
@@ -384,11 +384,11 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
 		if (vma_is_special_mapping(vma, &vdso_mapping) ||
 				vma_is_special_mapping(vma, &vvar_mapping)) {
-			up_write(&mm->mmap_sem);
+			mmap_write_unlock(mm);
 			return -EEXIST;
 		}
 	}
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 
 	return map_vdso(image, addr);
 }