[PATCH v5 08/16] tools/testing/vma: add tests for copy_vma() self-merge
From: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Date: 2026-08-13 17:35:47
Also in:
amd-gfx, dri-devel, intel-xe, kvm, linux-fsdevel, linux-kselftest, linux-mm, linux-perf-users, linux-s390, lkml
Subsystem:
memory mapping, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
Assert that a VMA can be moved backwards, forwards and between a preceding VMA and its old self. In the cases in which the VMA merges only with itself expect that to be achieved by expanding its old self, so assert that these function correctly. However in the case of a merge between a preceding VMA and itself the original VMA is removed, so assert that the preceding VMA replaces the one passed in as vmap and the merge is as expected. Acked-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> --- tools/testing/vma/tests/vma.c | 46 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/tools/testing/vma/tests/vma.c b/tools/testing/vma/tests/vma.c
index 754a2da06321..0d40d7ba2181 100644
--- a/tools/testing/vma/tests/vma.c
+++ b/tools/testing/vma/tests/vma.c@@ -33,7 +33,51 @@ static bool test_copy_vma(void) struct mm_struct mm = {}; bool need_locks = false; VMA_ITERATOR(vmi, &mm, 0); - struct vm_area_struct *vma, *vma_new, *vma_next; + struct vm_area_struct *vma, *vma_prev, *vma_new, *vma_next, *vma_orig; + + /* Move forwards, adjacent to old self - self-merge. */ + + vma = alloc_and_link_vma(&mm, 0x1000, 0x2000, 1, vma_flags); + vma_set_anonymous(vma); + vma_orig = vma; + vma_new = copy_vma(&vma, 0x2000, 0x1000, 1, &need_locks); + ASSERT_EQ(vma_new, vma_orig); + ASSERT_EQ(vma, vma_orig); + ASSERT_EQ(vma_new->vm_start, 0x1000); + ASSERT_EQ(vma_new->vm_end, 0x3000); + + cleanup_mm(&mm, &vmi); + + /* Move backwards, adjacent to old self - self-merge. */ + + vma = alloc_and_link_vma(&mm, 0x2000, 0x3000, 2, vma_flags); + vma_set_anonymous(vma); + vma_orig = vma; + vma_new = copy_vma(&vma, 0x1000, 0x1000, 2, &need_locks); + ASSERT_EQ(vma_new, vma_orig); + ASSERT_EQ(vma, vma_orig); + ASSERT_EQ(vma_new->vm_start, 0x1000); + ASSERT_EQ(vma_new->vm_end, 0x3000); + + cleanup_mm(&mm, &vmi); + + /* + * Move backwards between prior VMA and old self - self-merge and vma + * updated to a new VMA. + */ + + vma_prev = alloc_and_link_vma(&mm, 0x1000, 0x2000, 1, vma_flags); + vma_set_anonymous(vma_prev); + vma = alloc_and_link_vma(&mm, 0x3000, 0x4000, 3, vma_flags); + vma_set_anonymous(vma); + vma_orig = vma; + vma_new = copy_vma(&vma, 0x2000, 0x1000, 3, &need_locks); + ASSERT_NE(vma_new, vma_orig); + ASSERT_EQ(vma_new, vma); + ASSERT_EQ(vma_new->vm_start, 0x1000); + ASSERT_EQ(vma_new->vm_end, 0x4000); + + cleanup_mm(&mm, &vmi); /* Move backwards and do not merge. */
--
2.55.0