Add a new selftest which validates that a new_addr as a hint behaves
in the same way as mmap.
Signed-off-by: Brian Geffon <bgeffon@xxxxxxxxxx>
---
tools/testing/selftests/mm/mremap_dontunmap.c | 41 ++++++++++++++++++-
1 file changed, 40 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/mremap_dontunmap.c b/tools/testing/selftests/mm/mremap_dontunmap.c
index 1d75084b9ca5..ccce97c68019 100644
--- a/tools/testing/selftests/mm/mremap_dontunmap.c
+++ b/tools/testing/selftests/mm/mremap_dontunmap.c
@@ -224,6 +224,44 @@ static void mremap_dontunmap_simple_fixed()
ksft_test_result_pass("%s\n", __func__);
}
+// This test validates MREMAP_DONTUNMAP using a newaddr hint without
+// MREMAP_FIXED.
+static void mremap_dontunmap_simple_newaddr_hint()
+{
+ unsigned long num_pages = 5;
+
+ // This dest hint is intentionally not aligned.
+ void *new_addr_hint = (void*)0x999900010;
+
+ void *source_mapping =
+ mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ BUG_ON(source_mapping == MAP_FAILED, "mmap");
+ memset(source_mapping, 'a', num_pages * page_size);
+
+ void *remapped_mapping =
+ mremap(source_mapping, num_pages * page_size, num_pages * page_size,
+ MREMAP_DONTUNMAP | MREMAP_MAYMOVE,
+ new_addr_hint);
+ BUG_ON(remapped_mapping == MAP_FAILED, "mremap");
+
+ // And the source mapping will have had its ptes dropped.
+ BUG_ON(check_region_contains_byte
+ (source_mapping, num_pages * page_size, 0) != 0,
+ "source should have no ptes");
+
+ // And the remapped area will be filled with 'a's.
+ BUG_ON(check_region_contains_byte
+ (remapped_mapping, num_pages * page_size, 'a') != 0,
+ "dest should have remapped content");
+
+ BUG_ON(munmap(source_mapping, num_pages * page_size) == -1,
+ "unable to unmap source mapping");
+ BUG_ON(munmap(remapped_mapping, num_pages * page_size) == -1,
+ "unable to unmap source mapping");
+ ksft_test_result_pass("%s\n", __func__);
+}
+
// This test validates that we can MREMAP_DONTUNMAP for a portion of an
// existing mapping.
static void mremap_dontunmap_partial_mapping()
@@ -348,7 +386,7 @@ int main(void)
ksft_finished();
}
- ksft_set_plan(5);
+ ksft_set_plan(6);
// Keep a page sized buffer around for when we need it.
page_buffer =
@@ -359,6 +397,7 @@ int main(void)
mremap_dontunmap_simple();
mremap_dontunmap_simple_shmem();
mremap_dontunmap_simple_fixed();
+ mremap_dontunmap_simple_newaddr_hint();
mremap_dontunmap_partial_mapping();
mremap_dontunmap_partial_mapping_overwrite();
--
2.47.0.338.g60cca15819-goog
