From: Liam R. Howlett Date: Tue, 24 Jun 2025 15:48:23 +0000 (-0400) Subject: maple_tree: add testing for restoring maple state to active X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1f0bce2fa8c6bfd65cf78ad6ef6e0948fc55c7bb;p=thirdparty%2Fkernel%2Flinux.git maple_tree: add testing for restoring maple state to active Restoring maple status to ma_active on overflow/underflow when mas->node was NULL could have happened in the past, but was masked by a bug in mas_walk(). Add test cases that triggered the bug when the node was mas->node prior to fixing the maple state setup. Add a few extra tests around restoring the active maple status. Link: https://lore.kernel.org/all/202506191556.6bfc7b93-lkp@intel.com/ Link: https://lkml.kernel.org/r/20250624154823.52221-2-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Reviewed-by: Wei Yang Signed-off-by: Andrew Morton --- diff --git a/lib/test_maple_tree.c b/lib/test_maple_tree.c index 13e2a10d7554d..cb3936595b0d5 100644 --- a/lib/test_maple_tree.c +++ b/lib/test_maple_tree.c @@ -3177,6 +3177,7 @@ static noinline void __init check_state_handling(struct maple_tree *mt) void *entry, *ptr = (void *) 0x1234500; void *ptr2 = &ptr; void *ptr3 = &ptr2; + unsigned long index; /* Check MAS_ROOT First */ mtree_store_range(mt, 0, 0, ptr, GFP_KERNEL); @@ -3706,6 +3707,37 @@ static noinline void __init check_state_handling(struct maple_tree *mt) MT_BUG_ON(mt, mas.last != 0x1fff); MT_BUG_ON(mt, !mas_is_active(&mas)); + mas_unlock(&mas); + mtree_destroy(mt); + + mt_init_flags(mt, MT_FLAGS_ALLOC_RANGE); + mas_lock(&mas); + for (int count = 0; count < 30; count++) { + mas_set(&mas, count); + mas_store_gfp(&mas, xa_mk_value(count), GFP_KERNEL); + } + + /* Ensure mas_find works with MA_UNDERFLOW */ + mas_set(&mas, 0); + entry = mas_walk(&mas); + mas_set(&mas, 0); + mas_prev(&mas, 0); + MT_BUG_ON(mt, mas.status != ma_underflow); + MT_BUG_ON(mt, mas_find(&mas, ULONG_MAX) != entry); + + /* Restore active on mas_next */ + entry = mas_next(&mas, ULONG_MAX); + index = mas.index; + mas_prev(&mas, index); + MT_BUG_ON(mt, mas.status != ma_underflow); + MT_BUG_ON(mt, mas_next(&mas, ULONG_MAX) != entry); + + /* Ensure overflow -> active works */ + mas_prev(&mas, 0); + mas_next(&mas, index - 1); + MT_BUG_ON(mt, mas.status != ma_overflow); + MT_BUG_ON(mt, mas_next(&mas, ULONG_MAX) != entry); + mas_unlock(&mas); }