Merge patch series "Bump minimum supported version of LLVM for building the kernel to 15.0.0"

s390 and x86 have required LLVM 15 since

  30d17fac6aae ("scripts/min-tool-version.sh: raise minimum clang version to 15.0.0 for s390")
  7861640aac52 ("x86/build: Raise the minimum LLVM version to 15.0.0")

respectively. This series bumps the rest of the kernel to 15.0.0 to
match, which allows for a decent number of clean ups.

On the distros front, we will only leave behind Debian Bookworm and
Ubuntu Jammy. In both of those cases, builders / developers can either
use the kernel.org toolchains or https://apt.llvm.org to get newer
versions that will run on those distributions, if they cannot upgrade.

  archlinux:latest              clang version 20.1.8
  debian:oldoldstable-slim      Debian clang version 11.0.1-2
  debian:oldstable-slim         Debian clang version 14.0.6
  debian:stable-slim            Debian clang version 19.1.7 (3+b1)
  debian:testing-slim           Debian clang version 19.1.7 (3+b1)
  debian:unstable-slim          Debian clang version 19.1.7 (3+b2)
  fedora:41                     clang version 19.1.7 (Fedora 19.1.7-4.fc41)
  fedora:latest                 clang version 20.1.8 (Fedora 20.1.8-3.fc42)
  fedora:rawhide                clang version 20.1.8 (Fedora 20.1.8-3.fc43)
  opensuse/leap:latest          clang version 17.0.6
  opensuse/tumbleweed:latest    clang version 20.1.8
  ubuntu:focal                  clang version 10.0.0-4ubuntu1
  ubuntu:jammy                  Ubuntu clang version 14.0.0-1ubuntu1.1
  ubuntu:noble                  Ubuntu clang version 18.1.3 (1ubuntu1)
  ubuntu:latest                 Ubuntu clang version 18.1.3 (1ubuntu1)
  ubuntu:rolling                Ubuntu clang version 20.1.2 (0ubuntu1)
  ubuntu:devel                  Ubuntu clang version 20.1.8 (0ubuntu1)

Link: https://lore.kernel.org/r/20250821-bump-min-llvm-ver-15-v2-0-635f3294e5f0@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

13 files changed, 19 insertions, 71 deletions

diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
index bccfa19b45df..b38622b0d525 100644
--- a/Documentation/process/changes.rst
+++ b/Documentation/process/changes.rst
@@ -30,7 +30,7 @@ you probably needn't concern yourself with pcmciautils.
         Program        Minimal version       Command to check the version
 ====================== ===============  ========================================
 GNU C                  8.1              gcc --version
-Clang/LLVM (optional)  13.0.1           clang --version
+Clang/LLVM (optional)  15.0.0           clang --version
 Rust (optional)        1.78.0           rustc --version
 bindgen (optional)     0.65.1           bindgen --version
 GNU make               4.0              make --version
diff --git a/arch/Kconfig b/arch/Kconfig
index d1b4ffd6e085..4935c4c26f09 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1475,7 +1475,6 @@ config RANDOMIZE_KSTACK_OFFSET
 	bool "Support for randomizing kernel stack offset on syscall entry" if EXPERT
 	default y
 	depends on HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
-	depends on INIT_STACK_NONE || !CC_IS_CLANG || CLANG_VERSION >= 140000
 	help
 	  The kernel stack offset can be randomized (after pt_regs) by
 	  roughly 5 bits of entropy, frustrating memory corruption
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b1f3df39ed40..faf83015b961 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -166,15 +166,12 @@ config ARM
 	  <http://www.arm.linux.org.uk/>.
 
 config ARM_HAS_GROUP_RELOCS
-	def_bool y
-	depends on !LD_IS_LLD || LLD_VERSION >= 140000
-	depends on !COMPILE_TEST
+	def_bool !COMPILE_TEST
 	help
 	  Whether or not to use R_ARM_ALU_PC_Gn or R_ARM_LDR_PC_Gn group
-	  relocations, which have been around for a long time, but were not
-	  supported in LLD until version 14. The combined range is -/+ 256 MiB,
-	  which is usually sufficient, but not for allyesconfig, so we disable
-	  this feature when doing compile testing.
+	  relocations. The combined range is -/+ 256 MiB, which is usually
+	  sufficient, but not for allyesconfig, so we disable this feature
+	  when doing compile testing.
 
 config ARM_DMA_USE_IOMMU
 	bool
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e9bbfacc35a6..41c05562e9af 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1492,8 +1492,6 @@ choice
 
 config CPU_BIG_ENDIAN
 	bool "Build big-endian kernel"
-	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
-	depends on AS_IS_GNU || AS_VERSION >= 150000
 	help
 	  Say Y if you plan on running a kernel with a big-endian userspace.
 
@@ -2363,8 +2361,7 @@ config STACKPROTECTOR_PER_TASK
 
 config UNWIND_PATCH_PAC_INTO_SCS
 	bool "Enable shadow call stack dynamically using code patching"
-	# needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated
-	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
+	depends on CC_IS_CLANG
 	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
 	depends on SHADOW_CALL_STACK
 	select UNWIND_TABLES
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index caf508f6e9ec..bc7473505f4a 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -6,7 +6,7 @@ config MIPS
 	select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
 	select ARCH_HAS_CPU_CACHE_ALIASING
 	select ARCH_HAS_CPU_FINALIZE_INIT
-	select ARCH_HAS_CURRENT_STACK_POINTER if !CC_IS_CLANG || CLANG_VERSION >= 140000
+	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DEBUG_VIRTUAL if !64BIT
 	select ARCH_HAS_DMA_OPS if MACH_JAZZ
 	select ARCH_HAS_FORTIFY_SOURCE
diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index 684d3f453282..ffa82167c860 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -143,10 +143,6 @@ static inline int __copy_inst_from_kernel_nofault(ppc_inst_t *inst, u32 *src)
 {
 	unsigned int val, suffix;
 
-/* See https://github.com/ClangBuiltLinux/linux/issues/1521 */
-#if defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 140000
-	val = suffix = 0;
-#endif
 	__get_kernel_nofault(&val, src, u32, Efault);
 	if (IS_ENABLED(CONFIG_PPC64) && get_op(val) == OP_PREFIX) {
 		__get_kernel_nofault(&suffix, src + 1, u32, Efault);
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a4b233a0659e..850ba4b4b534 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -64,9 +64,8 @@ config RISCV
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
 	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
 	select ARCH_SUPPORTS_HUGETLBFS if MMU
-	# LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
-	select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
-	select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
+	select ARCH_SUPPORTS_LTO_CLANG
+	select ARCH_SUPPORTS_LTO_CLANG_THIN
 	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU
 	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
 	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
@@ -247,15 +246,9 @@ config HAVE_SHADOW_CALL_STACK
 	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
 	depends on $(ld-option,--no-relax-gp)
 
-config RISCV_USE_LINKER_RELAXATION
-	def_bool y
-	# https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
-	depends on !LD_IS_LLD || LLD_VERSION >= 150000
-
 # https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
 config ARCH_HAS_BROKEN_DWARF5
 	def_bool y
-	depends on RISCV_USE_LINKER_RELAXATION
 	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
 	depends on AS_IS_LLVM && AS_VERSION < 180000
 	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
@@ -627,7 +620,7 @@ config TOOLCHAIN_HAS_V
 	default y
 	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
 	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
-	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
+	depends on LD_IS_LLD || LD_VERSION >= 23800
 	depends on AS_HAS_OPTION_ARCH
 
 config RISCV_ISA_V
@@ -728,7 +721,7 @@ config TOOLCHAIN_HAS_ZBB
 	default y
 	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
 	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
-	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
+	depends on LD_IS_LLD || LD_VERSION >= 23900
 	depends on AS_HAS_OPTION_ARCH
 
 # This symbol indicates that the toolchain supports all v1.0 vector crypto
@@ -743,7 +736,7 @@ config TOOLCHAIN_HAS_ZBA
 	default y
 	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba)
 	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba)
-	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
+	depends on LD_IS_LLD || LD_VERSION >= 23900
 	depends on AS_HAS_OPTION_ARCH
 
 config RISCV_ISA_ZBA
@@ -778,7 +771,7 @@ config TOOLCHAIN_HAS_ZBC
 	default y
 	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
 	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
-	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
+	depends on LD_IS_LLD || LD_VERSION >= 23900
 	depends on AS_HAS_OPTION_ARCH
 
 config RISCV_ISA_ZBC
@@ -801,7 +794,7 @@ config TOOLCHAIN_HAS_ZBKB
 	default y
 	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb)
 	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb)
-	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
+	depends on LD_IS_LLD || LD_VERSION >= 23900
 	depends on AS_HAS_OPTION_ARCH
 
 config RISCV_ISA_ZBKB
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index df57654a615e..ecf2fcce2d92 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -46,17 +46,10 @@ else
 	KBUILD_LDFLAGS += -melf32lriscv
 endif
 
-ifndef CONFIG_RISCV_USE_LINKER_RELAXATION
-	KBUILD_CFLAGS += -mno-relax
-	KBUILD_AFLAGS += -mno-relax
-ifndef CONFIG_AS_IS_LLVM
-	KBUILD_CFLAGS += -Wa,-mno-relax
-	KBUILD_AFLAGS += -Wa,-mno-relax
-endif
 # LLVM has an issue with target-features and LTO: https://github.com/llvm/llvm-project/issues/59350
 # Ensure it is aware of linker relaxation with LTO, otherwise relocations may
 # be incorrect: https://github.com/llvm/llvm-project/issues/65090
-else ifeq ($(CONFIG_LTO_CLANG),y)
+ifeq ($(CONFIG_LTO_CLANG),y)
 	KBUILD_LDFLAGS += -mllvm -mattr=+c -mllvm -mattr=+relax
 endif
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index dc0e0c6ed075..6c12852e77c8 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -259,7 +259,7 @@ config DEBUG_INFO_NONE
 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
 	bool "Rely on the toolchain's implicit default DWARF version"
 	select DEBUG_INFO
-	depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
+	depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
 	help
 	  The implicit default version of DWARF debug info produced by a
 	  toolchain changes over time.
diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan
index 609ddfc73de5..4ce4b0c0109c 100644
--- a/lib/Kconfig.kcsan
+++ b/lib/Kconfig.kcsan
@@ -185,12 +185,6 @@ config KCSAN_WEAK_MEMORY
 	bool "Enable weak memory modeling to detect missing memory barriers"
 	default y
 	depends on KCSAN_STRICT
-	# We can either let objtool nop __tsan_func_{entry,exit}() and builtin
-	# atomics instrumentation in .noinstr.text, or use a compiler that can
-	# implement __no_kcsan to really remove all instrumentation.
-	depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
-		   CC_IS_GCC || CLANG_VERSION >= 140000
-	select OBJTOOL if HAVE_NOINSTR_HACK
 	help
 	  Enable support for modeling a subset of weak memory, which allows
 	  detecting a subset of data races due to missing memory barriers.
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 $(cc-option,-fsanitize=kernel-memory -fsanitize-memory-param-retval)
-
 config KMSAN_CHECK_PARAM_RETVAL
 	bool "Check for uninitialized values passed to and returned from functions"
 	default y
-	depends on HAVE_KMSAN_PARAM_RETVAL
 	help
 	  If the compiler supports -fsanitize-memory-param-retval, KMSAN will
 	  eagerly check every function parameter passed by value and every
diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
index 0d223b4a9445..99b5575c1ef7 100755
--- a/scripts/min-tool-version.sh
+++ b/scripts/min-tool-version.sh
@@ -24,12 +24,10 @@ gcc)
 	fi
 	;;
 llvm)
-	if [ "$SRCARCH" = s390 -o "$SRCARCH" = x86 ]; then
-		echo 15.0.0
-	elif [ "$SRCARCH" = loongarch ]; then
+	if [ "$SRCARCH" = loongarch ]; then
 		echo 18.0.0
 	else
-		echo 13.0.1
+		echo 15.0.0
 	fi
 	;;
 rustc)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index d14f20ef1db1..efa4c060ff4e 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2453,16 +2453,6 @@ static bool is_profiling_func(const char *name)
 	if (!strncmp(name, "__sanitizer_cov_", 16))
 		return true;
 
-	/*
-	 * Some compilers currently do not remove __tsan_func_entry/exit nor
-	 * __tsan_atomic_signal_fence (used for barrier instrumentation) with
-	 * the __no_sanitize_thread attribute, remove them. Once the kernel's
-	 * minimum Clang version is 14.0, this can be removed.
-	 */
-	if (!strncmp(name, "__tsan_func_", 12) ||
-	    !strcmp(name, "__tsan_atomic_signal_fence"))
-		return true;
-
 	return false;
 }