From 2233228b65291f8e9b04ee8be52bd2f694e12889 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Fri, 11 Sep 2026 18:14:42 -0400 Subject: idr: assert static storage for DEFINE_IDA() DEFINE_IDA() uses IDA_INIT(), which initializes the embedded XArray lock with a static spinlock initializer. For an automatic local IDA, lockdep cannot use the lock address as a persistent class key and reports "INFO: trying to register non-static key" before disabling itself. Apply ASSERT_STATIC_STORAGE() to DEFINE_IDA() so that this misuse is rejected at compile time. For example: void example(void) { DEFINE_IDA(ida); ida_destroy(&ida); } 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_IDA' DEFINE_IDA(ida); File-scope definitions and static DEFINE_IDA() within a function remain valid. Automatic local IDAs must instead be initialized with ida_init(). Direct uses of IDA_INIT() are not covered by this declaration check. Convert the five automatic local IDAs in the userspace radix-tree tests to ida_init() so they satisfy the new requirement. Validated file-scope and static local definitions with a kernel object build, and confirmed that an automatic local definition fails to compile. Link: https://lore.kernel.org/20260911221444.1523311-3-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/idr.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/idr.h b/include/linux/idr.h index 789e23e67444..e2a4b6298511 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -16,6 +16,7 @@ #include #include #include +#include struct idr { struct radix_tree_root idr_rt; @@ -269,7 +270,9 @@ struct ida { #define IDA_INIT(name) { \ .xa = XARRAY_INIT(name, IDA_INIT_FLAGS) \ } -#define DEFINE_IDA(name) struct ida name = IDA_INIT(name) +#define DEFINE_IDA(name) \ + struct ida name = IDA_INIT(name); \ + ASSERT_STATIC_STORAGE(name) int ida_alloc_range(struct ida *, unsigned int min, unsigned int max, gfp_t); void ida_free(struct ida *, unsigned int id); -- cgit v1.2.3