test_maple_tree: test modifications while iterating

BugLink: https://bugs.launchpad.net/bugs/2037005
[ Upstream commit 5159d64b335401fa83f18c27e2267f1eafc41bd3 ]

Add a testcase to ensure the iterator detects bad states on modifications
and does what the user expects

Link: https://lkml.kernel.org/r/20230120162650.984577-5-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 7a93c71a6714 ("maple_tree: fix 32 bit mas_next testing")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>

diff --git a/lib/test_maple_tree.c b/lib/test_maple_tree.c
index f7364b9fee939efdfc541b6d82cfb1c87f17255a..f1db333270e9fa4f2743a1e4c72420358eea5831 100644 (file)
--- a/lib/test_maple_tree.c
+++ b/lib/test_maple_tree.c
@@ -1709,6 +1709,74 @@ static noinline void check_forking(struct maple_tree *mt)
        mtree_destroy(&newmt);
 }
 
+static noinline void check_iteration(struct maple_tree *mt)
+{
+       int i, nr_entries = 125;
+       void *val;
+       MA_STATE(mas, mt, 0, 0);
+
+       for (i = 0; i <= nr_entries; i++)
+               mtree_store_range(mt, i * 10, i * 10 + 9,
+                                 xa_mk_value(i), GFP_KERNEL);
+
+       mt_set_non_kernel(99999);
+
+       i = 0;
+       mas_lock(&mas);
+       mas_for_each(&mas, val, 925) {
+               MT_BUG_ON(mt, mas.index != i * 10);
+               MT_BUG_ON(mt, mas.last != i * 10 + 9);
+               /* Overwrite end of entry 92 */
+               if (i == 92) {
+                       mas.index = 925;
+                       mas.last = 929;
+                       mas_store(&mas, val);
+               }
+               i++;
+       }
+       /* Ensure mas_find() gets the next value */
+       val = mas_find(&mas, ULONG_MAX);
+       MT_BUG_ON(mt, val != xa_mk_value(i));
+
+       mas_set(&mas, 0);
+       i = 0;
+       mas_for_each(&mas, val, 785) {
+               MT_BUG_ON(mt, mas.index != i * 10);
+               MT_BUG_ON(mt, mas.last != i * 10 + 9);
+               /* Overwrite start of entry 78 */
+               if (i == 78) {
+                       mas.index = 780;
+                       mas.last = 785;
+                       mas_store(&mas, val);
+               } else {
+                       i++;
+               }
+       }
+       val = mas_find(&mas, ULONG_MAX);
+       MT_BUG_ON(mt, val != xa_mk_value(i));
+
+       mas_set(&mas, 0);
+       i = 0;
+       mas_for_each(&mas, val, 765) {
+               MT_BUG_ON(mt, mas.index != i * 10);
+               MT_BUG_ON(mt, mas.last != i * 10 + 9);
+               /* Overwrite end of entry 76 and advance to the end */
+               if (i == 76) {
+                       mas.index = 760;
+                       mas.last = 765;
+                       mas_store(&mas, val);
+                       mas_next(&mas, ULONG_MAX);
+               }
+               i++;
+       }
+       /* Make sure the next find returns the one after 765, 766-769 */
+       val = mas_find(&mas, ULONG_MAX);
+       MT_BUG_ON(mt, val != xa_mk_value(76));
+       mas_unlock(&mas);
+       mas_destroy(&mas);
+       mt_set_non_kernel(0);
+}
+
 static noinline void check_mas_store_gfp(struct maple_tree *mt)
 {
 
@@ -2702,6 +2770,10 @@ static int maple_tree_seed(void)
        goto skip;
 #endif
 
+       mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE);
+       check_iteration(&tree);
+       mtree_destroy(&tree);
+
        mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE);
        check_forking(&tree);
        mtree_destroy(&tree);