Commit 7e7b2370 authored by Liam R. Howlett's avatar Liam R. Howlett Committed by Andrew Morton
Browse files

mm/vma: introduce abort_munmap_vmas() 

Extract clean up of failed munmap() operations from do_vmi_align_munmap().
This simplifies later patches in the series.

It is worth noting that the mas_for_each() loop now has a different upper
limit.  This should not change the number of vmas visited for reattaching
to the main vma tree (mm_mt), as all vmas are reattached in both
scenarios.

Link: https://lkml.kernel.org/r/20240830040101.822209-3-Liam.Howlett@oracle.com


Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: default avatarSuren Baghdasaryan <surenb@google.com>
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: Mark Brown <broonie@kernel.org>
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: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent b7012d51

mm/vma.c

+17 −5
Original line number Diff line number Diff line
@@ -668,6 +668,22 @@ void vma_complete(struct vma_prepare *vp, 
	validate_mm(mm);

}



/*

 * abort_munmap_vmas - Undo any munmap work and free resources

 *

 * Reattach any detached vmas and free up the maple tree used to track the vmas.

 */

static inline void abort_munmap_vmas(struct ma_state *mas_detach)

{

	struct vm_area_struct *vma;



	mas_set(mas_detach, 0);

	mas_for_each(mas_detach, vma, ULONG_MAX)

		vma_mark_detached(vma, false);



	__mt_destroy(mas_detach->tree);

}



/*

 * do_vmi_align_munmap() - munmap the aligned region from @start to @end.

 * @vmi: The vma iterator
@@ -834,11 +850,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, 
userfaultfd_error:

munmap_gather_failed:

end_split_failed:

	mas_set(&mas_detach, 0);

	mas_for_each(&mas_detach, next, end)

		vma_mark_detached(next, false);



	__mt_destroy(&mt_detach);

	abort_munmap_vmas(&mas_detach);

start_split_failed:

map_count_exceeded:

	validate_mm(mm);