mm: move internal core VMA manipulation functions to own file

This patch introduces vma.c and moves internal core VMA manipulation
functions to this file from mmap.c.

This allows us to isolate VMA functionality in a single place such that we
can create userspace testing code that invokes this functionality in an
environment where we can implement simple unit tests of core
functionality.

This patch ensures that core VMA functionality is explicitly marked as
such by its presence in mm/vma.h.

It also places the header includes required by vma.c in vma_internal.h,
which is simply imported by vma.c.  This makes the VMA functionality
testable, as userland testing code can simply stub out functionality as
required.

Link: https://lkml.kernel.org/r/c77a6aafb4c42aaadb8e7271a853658cbdca2e22.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Gow <davidgow@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Kees Cook <kees@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rae Moar <rmoar@google.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 0 insertions, 35 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1c0d88446eb8..bd219ac9c026 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1005,21 +1005,6 @@ static inline struct vm_area_struct *vma_prev(struct vma_iterator *vmi)
 	return mas_prev(&vmi->mas, 0);
 }
 
-static inline unsigned long vma_iter_addr(struct vma_iterator *vmi)
-{
-	return vmi->mas.index;
-}
-
-static inline unsigned long vma_iter_end(struct vma_iterator *vmi)
-{
-	return vmi->mas.last + 1;
-}
-static inline int vma_iter_bulk_alloc(struct vma_iterator *vmi,
-				      unsigned long count)
-{
-	return mas_expected_entries(&vmi->mas, count);
-}
-
 static inline int vma_iter_clear_gfp(struct vma_iterator *vmi,
 			unsigned long start, unsigned long end, gfp_t gfp)
 {
@@ -2534,21 +2519,6 @@ int get_cmdline(struct task_struct *task, char *buffer, int buflen);
 #define  MM_CP_UFFD_WP_ALL                 (MM_CP_UFFD_WP | \
 					    MM_CP_UFFD_WP_RESOLVE)
 
-bool vma_needs_dirty_tracking(struct vm_area_struct *vma);
-bool vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot);
-static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struct *vma)
-{
-	/*
-	 * We want to check manually if we can change individual PTEs writable
-	 * if we can't do that automatically for all PTEs in a mapping. For
-	 * private mappings, that's always the case when we have write
-	 * permissions as we properly have to handle COW.
-	 */
-	if (vma->vm_flags & VM_SHARED)
-		return vma_wants_writenotify(vma, vma->vm_page_prot);
-	return !!(vma->vm_flags & VM_WRITE);
-
-}
 bool can_change_pte_writable(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t pte);
 extern long change_protection(struct mmu_gather *tlb,
@@ -3256,12 +3226,7 @@ void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
 
 /* mmap.c */
 extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
-extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
-extern void unlink_file_vma(struct vm_area_struct *);
-extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
-	unsigned long addr, unsigned long len, pgoff_t pgoff,
-	bool *need_rmap_locks);
 extern void exit_mmap(struct mm_struct *);
 int relocate_vma_down(struct vm_area_struct *vma, unsigned long shift);