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 908B537D10E; Tue, 25 Aug 2026 01:55:50 +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=1787622952; cv=none; b=HuK4WdQG5XLXq8nADrEcTI261BCihEzOnJSSBvR5XNoX4r/hFRNFLygDtCxWVwai/ptJu1MscmIkN/OCO4edg/48dds/VwHxt6kF1fXMHf4MOakqEtCLBN1W0hlOkshPmDPRg7cXhGsKPw0cIzKrk1tXv75POoI1Uu9DqKNWZd0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787622952; c=relaxed/simple; bh=cF7VmJBZwpvj471jcrw3ANTbEEfzFwLM1TdebdU0P8w=; h=Date:To:From:Subject:Message-Id; b=RvLdWFV8lJANKBbeGI+haPPQiS1S2fxcbr69cualv3/1p1aR6d/U0g8F1YBMCaqdIX8ICHK4qgxi2yEgRB3faJiRFNrouD+leXk9GSx1VIfhKAjqWY6e3imX1BwUS988gwJLwOvSp8g0vuzByHQbsKQH49VmaqN951GPEUujDgA= 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=u1L+iJiR; 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="u1L+iJiR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CFB01F000E9; Tue, 25 Aug 2026 01:55:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1787622950; bh=N4YM/pY7RVShPODW0spjrrFFcHLqORgyCUARmHqKurs=; h=Date:To:From:Subject; b=u1L+iJiRAA7kADE5Wv+CmK+R9pM0XJn5fzAA02khjZ4ClVDV8DuhI6Z1ERDDakue5 5eLwlFHsr+nJAbZHx7K1Yzjinhn+cTvunudogtW+wO2soqnwQwkYJo4ZwNCeqR2vlh A4SX+eBzOUFuu7JQoL8AoaBaJn7pimz9U6Sd9XbM= Date: Mon, 24 Aug 2026 18:55:49 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,rppt@kernel.org,ndesaulniers@google.com,morbo@google.com,kees@kernel.org,justinstitt@google.com,nathan@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] arch_numa-avoid-false-positive-fortify-warning-in-setup_node_to_cpumask_map.patch removed from -mm tree Message-Id: <20260825015550.5CFB01F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: arch_numa: avoid false positive fortify warning in setup_node_to_cpumask_map() has been removed from the -mm tree. Its filename was arch_numa-avoid-false-positive-fortify-warning-in-setup_node_to_cpumask_map.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: Nathan Chancellor Subject: arch_numa: avoid false positive fortify warning in setup_node_to_cpumask_map() Date: Thu, 13 Aug 2026 20:12:55 -0700 When building ARCH=riscv using clang with CONFIG_FORTIFY_SOURCE and CONFIG_UBSAN_BOUNDS enabled, CONFIG_NR_CPUS > 64, and the default value of 2 for CONFIG_NODES_SHIFT, there is a compiletime warning from the fortify routines. In file included from mm/arch_numa.c:11: In file included from include/linux/acpi.h:14: In file included from include/linux/resource_ext.h:11: In file included from include/linux/slab.h:17: In file included from include/linux/gfp.h:7: In file included from include/linux/mmzone.h:8: In file included from include/linux/spinlock.h:60: In file included from include/linux/interrupt_rc.h:17: In file included from include/linux/smp.h:13: In file included from include/linux/cpumask.h:11: In file included from include/linux/bitmap.h:13: In file included from include/linux/string.h:383: include/linux/fortify-string.h:430:4: warning: call to '__write_overflow_field' declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribue-warning] 430 | __write_overflow_field(p_size_field, size); | ^ include/linux/fortify-string.h:430:4: note: called by function 'fortify_memset_chk(unsigned long, unsigned long, unsigned long)' include/linux/bitmap.h:248:3: note: inlined by function 'setup_node_to_cpumask_map' 248 | memset(dst, 0, len); | ^ include/linux/fortify-string.h:462:25: note: expanded from macro 'memset' 462 | #define memset(p, c, s) __fortify_memset_chk(p, c, s, \ | ^ include/linux/fortify-string.h:453:2: note: expanded from macro '__fortify_memset_chk' 453 | fortify_memset_chk(__fortify_size, p_size, p_size_field), \ | ^ include/linux/fortify-string.h:430:4: note: use '-gline-directives-only' (implied by '-g1') or higher for more accurate inlining chain locations 430 | __write_overflow_field(p_size_field, size); | ^ 1 warning generated. In this configuration, MAX_NUMNODES is 4. clang unrolls the for loop in setup_node_to_cpumask_map() past this, which triggers the fortify check when accessing node_to_cpumask_map on the theoretical fifth loop iteration because it would be an out of bounds write. Make it clear to clang that nr_node_ids is bounded by MAX_NUMNODES due to the logic in setup_nr_node_ids() by early returning in setup_node_to_cpumask_map() should that condition be violated. Link: https://lore.kernel.org/20260813-arch_numa-avoid-fortify-warning-v2-1-093ad97a78df@kernel.org Signed-off-by: Nathan Chancellor Closes: https://github.com/ClangBuiltLinux/linux/issues/2174 Reviewed-by: Mike Rapoport (Microsoft) Cc: Kees Cook Cc: Bill Wendling Cc: Justin Stitt Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Signed-off-by: Andrew Morton --- mm/arch_numa.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/mm/arch_numa.c~arch_numa-avoid-false-positive-fortify-warning-in-setup_node_to_cpumask_map +++ a/mm/arch_numa.c @@ -105,6 +105,18 @@ static void __init setup_node_to_cpumask if (nr_node_ids == MAX_NUMNODES) setup_nr_node_ids(); + /* + * This check should never be true but it makes it clear to compilers + * that node_to_cpumask_map is bound by nr_node_ids, avoiding false + * positive fortify warnings when accessing node_to_cpumask_map in the + * for loop below. + */ + if (unlikely(nr_node_ids > MAX_NUMNODES)) { + pr_err("nr_node_ids (%u) is larger than MAX_NUMNODES (%u)\n", + nr_node_ids, MAX_NUMNODES); + return; + } + /* allocate and clear the mapping */ for (node = 0; node < nr_node_ids; node++) { alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]); _ Patches currently in -mm which might be from nathan@kernel.org are