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: Lorenzo 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: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Lorenzo Stoakes 2024-10-17 15:31:46 +01:00 committed by Andrew Morton
parent c4d91e225f
commit e8133a7799

View file

@ -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