mm: abstract vma_expand() to use vma_merge_struct

The purpose of the vmg is to thread merge state through functions and
avoid egregious parameter lists.  We expand this to vma_expand(), which is
used for a number of merge cases.

Accordingly, adjust its callers, mmap_region() and relocate_vma_down(), to
use a vmg.

An added purpose of this change is the ability in a future commit to
perform all new VMA range merging using vma_expand().

Link: https://lkml.kernel.org/r/4bc8c9dbc9ca52452ef8e587b28fe555854ceb38.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 1 insertions, 4 deletions

diff --git a/mm/vma.h b/mm/vma.h
index e761713f855f..218d884ff5ff 100644
--- a/mm/vma.h
+++ b/mm/vma.h
@@ -128,10 +128,7 @@ void init_vma_prep(struct vma_prepare *vp,
 void vma_complete(struct vma_prepare *vp,
 		  struct vma_iterator *vmi, struct mm_struct *mm);
 
-int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
-	       unsigned long start, unsigned long end, pgoff_t pgoff,
-	       struct vm_area_struct *next);
-
+int vma_expand(struct vma_merge_struct *vmg);
 int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
 	       unsigned long start, unsigned long end, pgoff_t pgoff);