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From: Nathan Chancellor <nathan@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>, Kees Cook <kees@kernel.org>,
	 Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
	 Bill Wendling <morbo@google.com>,
	Justin Stitt <justinstitt@google.com>,
	 llvm@lists.linux.dev, patches@lists.linux.dev,
	 Marco Elver <elver@google.com>,
	Nathan Chancellor <nathan@kernel.org>,
	 kasan-dev@googlegroups.com
Subject: [PATCH v2 12/12] KMSAN: Remove tautological checks
Date: Thu, 21 Aug 2025 14:15:49 -0700	[thread overview]
Message-ID: <20250821-bump-min-llvm-ver-15-v2-12-635f3294e5f0@kernel.org> (raw)
In-Reply-To: <20250821-bump-min-llvm-ver-15-v2-0-635f3294e5f0@kernel.org>

Now that the minimum supported version of LLVM for building the kernel
has been bumped to 15.0.0, two KMSAN checks can be cleaned up.

CONFIG_HAVE_KMSAN_COMPILER will always be true when using clang so
remove the cc-option test and use a simple check for CONFIG_CC_IS_CLANG.

CONFIG_HAVE_KMSAN_PARAM_RETVAL will always be true so it can be removed
outright.

Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
Cc: kasan-dev@googlegroups.com
---
 lib/Kconfig.kmsan | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/lib/Kconfig.kmsan b/lib/Kconfig.kmsan
index 0541d7b079cc..7251b6b59e69 100644
--- a/lib/Kconfig.kmsan
+++ b/lib/Kconfig.kmsan
@@ -3,10 +3,7 @@ config HAVE_ARCH_KMSAN
 	bool
 
 config HAVE_KMSAN_COMPILER
-	# Clang versions <14.0.0 also support -fsanitize=kernel-memory, but not
-	# all the features necessary to build the kernel with KMSAN.
-	depends on CC_IS_CLANG && CLANG_VERSION >= 140000
-	def_bool $(cc-option,-fsanitize=kernel-memory -mllvm -msan-disable-checks=1)
+	def_bool CC_IS_CLANG
 
 config KMSAN
 	bool "KMSAN: detector of uninitialized values use"
@@ -28,15 +25,9 @@ config KMSAN
 
 if KMSAN
 
-config HAVE_KMSAN_PARAM_RETVAL
-	# -fsanitize-memory-param-retval is supported only by Clang >= 14.
-	depends on HAVE_KMSAN_COMPILER
-	def_bool $(cc-option,-fsanitize=kernel-memory -fsanitize-memory-param-retval)
-
 config KMSAN_CHECK_PARAM_RETVAL
 	bool "Check for uninitialized values passed to and returned from functions"
 	default y
-	depends on HAVE_KMSAN_PARAM_RETVAL
 	help
 	  If the compiler supports -fsanitize-memory-param-retval, KMSAN will
 	  eagerly check every function parameter passed by value and every

-- 
2.50.1


  parent reply	other threads:[~2025-08-21 21:16 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-21 21:15 [PATCH v2 00/12] Bump minimum supported version of LLVM for building the kernel to 15.0.0 Nathan Chancellor
2025-08-21 21:15 ` [PATCH v2 01/12] kbuild: Bump minimum " Nathan Chancellor
2025-08-21 21:15 ` [PATCH v2 02/12] arch/Kconfig: Drop always true condition from RANDOMIZE_KSTACK_OFFSET Nathan Chancellor
2025-08-21 21:15 ` [PATCH v2 03/12] ARM: Clean up definition of ARM_HAS_GROUP_RELOCS Nathan Chancellor
2025-08-22  7:05   ` Arnd Bergmann
2025-08-22 20:03     ` Arnd Bergmann
2025-08-26 13:18       ` Ard Biesheuvel
2025-08-21 21:15 ` [PATCH v2 04/12] arm64: Remove tautological LLVM Kconfig conditions Nathan Chancellor
2025-08-21 21:15 ` [PATCH v2 05/12] mips: Unconditionally select ARCH_HAS_CURRENT_STACK_POINTER Nathan Chancellor
2025-08-21 21:15 ` [PATCH v2 06/12] powerpc: Drop unnecessary initializations in __copy_inst_from_kernel_nofault() Nathan Chancellor
2025-08-22 10:01   ` Christophe Leroy
2025-08-21 21:15 ` [PATCH v2 07/12] riscv: Remove version check for LTO_CLANG selects Nathan Chancellor
2025-08-22 12:31   ` Alexandre Ghiti
2025-08-27 17:31   ` Conor Dooley
2025-08-21 21:15 ` [PATCH v2 08/12] riscv: Unconditionally use linker relaxation Nathan Chancellor
2025-08-22 12:35   ` Alexandre Ghiti
2025-08-21 21:15 ` [PATCH v2 09/12] riscv: Remove ld.lld version checks from many TOOLCHAIN_HAS configs Nathan Chancellor
2025-08-22 12:38   ` Alexandre Ghiti
2025-08-27 17:30   ` Conor Dooley
2025-08-21 21:15 ` [PATCH v2 10/12] lib/Kconfig.debug: Drop CLANG_VERSION check from DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT Nathan Chancellor
2025-08-21 21:15 ` [PATCH v2 11/12] objtool: Drop noinstr hack for KCSAN_WEAK_MEMORY Nathan Chancellor
2025-08-21 21:15 ` Nathan Chancellor [this message]
2025-08-29 22:33 ` [PATCH v2 00/12] Bump minimum supported version of LLVM for building the kernel to 15.0.0 Nathan Chancellor

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