IDR test suite: Check handling negative end correctly

One of the charming quirks of the idr_alloc() interface is that you
can pass a negative end and it will be interpreted as "maximum".  Ensure
we don't break that.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/testing/radix-tree/idr-test.c b/tools/testing/radix-tree/idr-test.c
index 193450b29bf0..892ef8855b02 100644
--- a/tools/testing/radix-tree/idr-test.c
+++ b/tools/testing/radix-tree/idr-test.c
@@ -207,6 +207,7 @@ void idr_checks(void)
                 assert(idr_alloc(&idr, item, i, i + 10, GFP_KERNEL) == i);
         }
         assert(idr_alloc(&idr, DUMMY_PTR, i - 2, i, GFP_KERNEL) == -ENOSPC);
+        assert(idr_alloc(&idr, DUMMY_PTR, i - 2, i + 10, GFP_KERNEL) == -ENOSPC);
 
         idr_for_each(&idr, item_idr_free, &idr);
         idr_destroy(&idr);