From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 251AB41A776 for ; Fri, 9 Oct 2026 05:59:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791525567; cv=none; b=c0vEyccirp3sH+NHFJEDG9uNvqb0C0bMM7IZ+uhfhXSPj1vOIUJq+roFV8nm7x66ORmJfN8splS3EIJh6ejIhPyjglt10w3P2yeaIMYSAIYDHZm3/f9Rko9tIdUoZyP0sZ8spR9x3XVEarJMF+wbkASkrOHB59FR2YtD/v8O13k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791525567; c=relaxed/simple; bh=Vm+wDbaTx49QZAMM2H74ZuRZpnjQ8IefGi4HF9tA5lo=; h=Date:To:From:Subject:Message-Id; b=N7cldvMrO08PdnvsX31WdQgGFb3nAV8zV8mBmdrAbzwqdUBKJYvzWpqnuvPsCHa613DQdpfLrBoIxT4aQWkgg+d7BUkecYjJDJD9jK3vqRkzOVZQy/nB29zLYN7ZN20dvKoYbrHAtJkz0BzR/qD8WsC4114bJ/qxnZxJWzZeNuw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=eVieSwFv; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="eVieSwFv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE01F1F000FF; Fri, 9 Oct 2026 05:59:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1791525566; bh=SqxIntLP/i0W4h2Chpl1LDsroCa28U5LIGlbADwbSlA=; h=Date:To:From:Subject; b=eVieSwFvApoRm7zybeqOc7zIU3laHhG95ahL3229LgdRRfK9BwhGdcJcWPyvviNFC Q86L1K4ZWE60cuopmZCa64bQCY5TB75wp9Ulr42w7VVxz2tPLvZ8a4rxQNwzUamqEj CW9uQnDOsVoQPdfSgAd5bxZjZDqF/he93PGt6a0U= Date: Thu, 08 Oct 2026 22:59:25 -0700 To: mm-commits@vger.kernel.org,willy@infradead.org,sparse@chrisli.org,liam@infradead.org,andrewjballance@gmail.com,aliceryhl@google.com,ynorov@nvidia.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] compilerh-add-assert_static_storage.patch removed from -mm tree Message-Id: <20261009055925.EE01F1F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: compiler.h: add ASSERT_STATIC_STORAGE() has been removed from the -mm tree. Its filename was compilerh-add-assert_static_storage.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Yury Norov Subject: compiler.h: add ASSERT_STATIC_STORAGE() Date: Fri, 11 Sep 2026 18:14:41 -0400 Patch series "Catch automatic storage in IDA and Maple Tree definitions". A 0day report [1] from the region allocation benchmark exposed a lockdep initialization bug: a stack-local Maple Tree used MTREE_INIT(), whose embedded lock has a static initializer. On the first allocation, lockdep rejected the lock address as a non-static class key and disabled locking validation. The IDA benchmark had the same issue, masked because it ran after Maple Tree had already disabled lockdep. The fix [2] switches the test to using mt_init_flags() and ida_init(). This series adds a compile-time check to the related DEFINE_IDA() and DEFINE_MTREE() declaration macros to catch the same class of mistake earlier. Patch 1 introduces ASSERT_STATIC_STORAGE(). It declares an unused static pointer initialized with the object's address, requiring that address to be a valid static initializer. Patches 2 and 3 apply the helper to IDA and Maple Tree definitions, respectively. The helper is mirrored in the tools compiler header. The existing automatic local IDAs and Maple Trees in the userspace radix-tree tests are converted to runtime initialization. The interval-tree span test keeps its existing mt_init_flags() call and uses a plain Maple Tree declaration. For example, an automatic local definition: void example(void) { DEFINE_IDA(ida); ida_destroy(&ida); } now produces: error: initializer element is not constant note: in expansion of macro 'ASSERT_STATIC_STORAGE' note: in expansion of macro 'DEFINE_IDA' File-scope definitions and static local definitions remain valid. Automatic local objects should use ida_init(), mt_init(), or mt_init_flags(). The check is limited to declaration macros. Direct uses of IDA_INIT(), MTREE_INIT(), and MTREE_INIT_EXT() remain unchanged. The helper cannot be inserted directly into those initializer expressions because it expands to a declaration. Validated by GCC and Clang checks accepting static storage and rejecting automatic storage The userspace IDR/IDA and Maple Tree test are passed as well. This patch (of 3): Static lock initializers rely on a persistent object address when lockdep assigns a lock-class key. Using such an initializer for an automatic local object can compile successfully but disable lockdep on the first lock acquisition. Add ASSERT_STATIC_STORAGE() for declaration macros that require static storage duration. It declares an unused static pointer initialized with the object's address. An automatic local object's address is not a valid static initializer, so the compiler rejects it. Mirror the helper in tools/include/linux/compiler.h because the userspace radix-tree tests include the kernel IDA and Maple Tree headers with the tools compiler definitions. For example: void example(void) { int object; ASSERT_STATIC_STORAGE(object); } GCC reports: error: initializer element is not constant name##_storage_check = &(name) ^ note: in expansion of macro 'ASSERT_STATIC_STORAGE' ASSERT_STATIC_STORAGE(object); File-scope objects and static local objects remain valid. The helper takes an object identifier and must be used as a declaration after that object has been declared. Link: https://lore.kernel.org/all/20260911155244.1406122-1-ynorov@nvidia.com/ Link: https://lore.kernel.org/20260911221444.1523311-2-ynorov@nvidia.com Link: https://download.01.org/0day-ci/archive/20260910/202609101106.771b567e-lkp@intel.com/ [1] Link: https://lore.kernel.org/all/20260911155244.1406122-1-ynorov@nvidia.com/ [2] 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/compiler.h | 5 +++++ tools/include/linux/compiler.h | 5 +++++ 2 files changed, 10 insertions(+) --- a/include/linux/compiler.h~compilerh-add-assert_static_storage +++ a/include/linux/compiler.h @@ -275,6 +275,11 @@ static inline void *offset_to_ptr(const #define __ADDRESSABLE(sym) \ ___ADDRESSABLE(sym, __section(".discard.addressable")) +/* Enforce static storage duration. */ +#define ASSERT_STATIC_STORAGE(name) \ + static typeof(name) * const __always_unused \ + name##_storage_check = &(name) + /* * This returns a constant expression while determining if an argument is * a constant expression, most importantly without evaluating the argument. --- a/tools/include/linux/compiler.h~compilerh-add-assert_static_storage +++ a/tools/include/linux/compiler.h @@ -73,6 +73,11 @@ # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) #endif +/* Enforce static storage duration. */ +#define ASSERT_STATIC_STORAGE(name) \ + static typeof(name) * const __always_unused \ + name##_storage_check = &(name) + /* * This returns a constant expression while determining if an argument is * a constant expression, most importantly without evaluating the argument. _ Patches currently in -mm which might be from ynorov@nvidia.com are