From 778be1d8b57f3e0385324bb9d21ef048d88eb88f Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Fri, 11 Sep 2026 18:14:43 -0400 Subject: [PATCH] maple_tree: assert static storage for DEFINE_MTREE() DEFINE_MTREE() uses MTREE_INIT(), which initializes the tree's embedded lock with a static spinlock initializer. If the tree is an automatic local object, lockdep rejects its address as a non-static class key and disables locking validation on the first lock acquisition. Apply ASSERT_STATIC_STORAGE() to DEFINE_MTREE() to catch automatic local definitions at compile time. For example: void example(void) { DEFINE_MTREE(mt); mtree_destroy(&mt); } GCC reports: error: initializer element is not constant name##_storage_check = &(name) ^ note: in expansion of macro 'ASSERT_STATIC_STORAGE' ASSERT_STATIC_STORAGE(name) note: in expansion of macro 'DEFINE_MTREE' DEFINE_MTREE(mt); File-scope definitions and static local trees remain valid. Automatic local trees must instead use mt_init() or mt_init_flags(). Direct uses of MTREE_INIT() and MTREE_INIT_EXT() are unchanged. Replace the local DEFINE_MTREE() in the interval-tree span test with a plain declaration; the test already initializes the tree with mt_init_flags() before use. Convert the three local Maple Trees in the userspace radix-tree tests to mt_init(). Validated file-scope and static local definitions with a kernel object build, and confirmed that an automatic local definition fails to compile. The Maple Tree test and region allocation benchmark objects also build with lockdep enabled. Link: https://lore.kernel.org/20260911221444.1523311-4-ynorov@nvidia.com Signed-off-by: Yury Norov Signed-off-by: Andrew Morton Cc: Alice Ryhl Cc: Andrew Ballance Cc: Christopher Li Cc: Liam R. Howlett Cc: Matthew Wilcox (Oracle) --- include/linux/maple_tree.h | 4 +++- lib/interval_tree_test.c | 2 +- tools/testing/radix-tree/maple.c | 12 +++++++++--- 3 files changed, 13 insertions(+), 5 deletions(-) diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h index e595ae5cd0ee..e30e57f5f3df 100644 --- a/include/linux/maple_tree.h +++ b/include/linux/maple_tree.h @@ -9,6 +9,7 @@ */ #include +#include #include #include @@ -297,7 +298,8 @@ struct maple_tree { #endif #define DEFINE_MTREE(name) \ - struct maple_tree name = MTREE_INIT(name, 0) + struct maple_tree name = MTREE_INIT(name, 0); \ + ASSERT_STATIC_STORAGE(name) #define mtree_lock(mt) spin_lock((&(mt)->ma_lock)) #define mtree_lock_nested(mas, subclass) \ diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c index b0b07270ce7c..06f77fb3179f 100644 --- a/lib/interval_tree_test.c +++ b/lib/interval_tree_test.c @@ -244,7 +244,7 @@ static int span_iteration_check(void) unsigned long start, last; struct interval_tree_span_iter span, mas_span; - DEFINE_MTREE(tree); + struct maple_tree tree; MA_STATE(mas, &tree, 0, 0); diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c index d967e76a3c06..bfe4b8626c42 100644 --- a/tools/testing/radix-tree/maple.c +++ b/tools/testing/radix-tree/maple.c @@ -36022,10 +36022,12 @@ static noinline void __init check_erase_rebalance(struct maple_tree *mt) static noinline void __init check_mtree_dup(struct maple_tree *mt) { - DEFINE_MTREE(new); + struct maple_tree new; int i, j, ret, count = 0; unsigned int rand_seed = 17, rand; + mt_init(&new); + /* store a value at [0, 0] */ mt_init_flags(mt, 0); mtree_store_range(mt, 0, 0, xa_mk_value(0), GFP_KERNEL); @@ -36319,7 +36321,9 @@ static inline int check_vma_modification(struct maple_tree *mt) void farmer_tests(void) { struct maple_node *node; - DEFINE_MTREE(tree); + struct maple_tree tree; + + mt_init(&tree); mt_dump(&tree, mt_dump_dec); @@ -36432,9 +36436,11 @@ static unsigned long get_last_index(struct ma_state *mas) static void test_spanning_store_regression(void) { unsigned long from = 0, to = 0; - DEFINE_MTREE(tree); + struct maple_tree tree; MA_STATE(mas, &tree, 0, 0); + mt_init(&tree); + /* * Build a 3-level tree. We require a parent node below the root node * and 2 leaf nodes under it, so we can span the entirety of the right