mm/vma: correct incorrect vma.h inclusion

The only files which should be including vma.h are the implementation files
for the core VMA logic - vma.c, vma_init.c, and vma_exec.c.

This is in order to allow for userland testing of core VMA logic. In this
cases, vma_internal.h and vma.h are included, providing both the
dependencies upon which the core VMA logic requires and its declarations.

Userland testable VMA logic is achieved by having separate vma_internal.h
implementations for userland and kernel.

Callers other than the core VMA implementation should include internal.h
instead. This header does not need to include vma_internal.h as it only
contains the vma.h declarations, for which the includes already present
suffice.

Update code to reflect this, update comments to reflect the fact there are
3 VMA implementation files and document things more clearly.

While we're here, slightly improve the language of the comment describing
vma_exec.c.

No functional change intended.

Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-30-2a5aa403d977@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Ackerley Tng <ackerleytng@google.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Kai Huang <kai.huang@intel.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: SJ Park <sj@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/mm/vma_exec.c b/mm/vma_exec.c
index 13a05e041195..ef1fa2b161f3 100644
--- a/mm/vma_exec.c
+++ b/mm/vma_exec.c
@@ -1,10 +1,14 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
 /*
- * Functions explicitly implemented for exec functionality which however are
- * explicitly VMA-only logic.
+ * Functions provided for exec functionality which however are
+ * specifically VMA-only logic.
  */
 
+/*
+ * To allow for userland testing we place internal dependencies in
+ * vma_internal.h and external VMA API declarations in vma.h.
+ */
 #include "vma_internal.h"
 #include "vma.h"