Commit e8133a77 authored by Lorenzo Stoakes's avatar Lorenzo Stoakes Committed by Andrew Morton
Browse files

tools: testing: add expand-only mode VMA test 

Add a test to assert that VMG_FLAG_JUST_EXPAND functions as expected - that
is, when the VMA iterator is positioned at the previous VMA and no VMAs
proceed it, we observe an expansion with all state as expected.

Explicitly place a prior VMA that would otherwise fail this test if the
mode were not enabled (as it would traverse to the previous-previous VMA).

Link: https://lkml.kernel.org/r/d2f88330254a6448092412bf7dfe077a579ab0dc.1729174352.git.lorenzo.stoakes@oracle.com


Signed-off-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: kernel test robot <oliver.sang@intel.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent c4d91e22

tools/testing/vma/vma.c

+40 −0
Original line number Diff line number Diff line
@@ -1522,6 +1522,45 @@ static bool test_copy_vma(void) 
	return true;

}



static bool test_expand_only_mode(void)

{

	unsigned long flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;

	struct mm_struct mm = {};

	VMA_ITERATOR(vmi, &mm, 0);

	struct vm_area_struct *vma_prev, *vma;

	VMG_STATE(vmg, &mm, &vmi, 0x5000, 0x9000, flags, 5);



	/*

	 * Place a VMA prior to the one we're expanding so we assert that we do

	 * not erroneously try to traverse to the previous VMA even though we

	 * have, through the use of VMG_FLAG_JUST_EXPAND, indicated we do not

	 * need to do so.

	 */

	alloc_and_link_vma(&mm, 0, 0x2000, 0, flags);



	/*

	 * We will be positioned at the prev VMA, but looking to expand to

	 * 0x9000.

	 */

	vma_iter_set(&vmi, 0x3000);

	vma_prev = alloc_and_link_vma(&mm, 0x3000, 0x5000, 3, flags);

	vmg.prev = vma_prev;

	vmg.merge_flags = VMG_FLAG_JUST_EXPAND;



	vma = vma_merge_new_range(&vmg);

	ASSERT_NE(vma, NULL);

	ASSERT_EQ(vma, vma_prev);

	ASSERT_EQ(vmg.state, VMA_MERGE_SUCCESS);

	ASSERT_EQ(vma->vm_start, 0x3000);

	ASSERT_EQ(vma->vm_end, 0x9000);

	ASSERT_EQ(vma->vm_pgoff, 3);

	ASSERT_TRUE(vma_write_started(vma));

	ASSERT_EQ(vma_iter_addr(&vmi), 0x3000);



	cleanup_mm(&mm, &vmi);

	return true;

}



int main(void)

{

	int num_tests = 0, num_fail = 0;
@@ -1553,6 +1592,7 @@ int main(void) 
	TEST(vmi_prealloc_fail);

	TEST(merge_extend);

	TEST(copy_vma);

	TEST(expand_only_mode);



#undef TEST