@@ -948,15 +948,6 @@ CC_FLAGS_LTO += -fvisibility=hidden
# Limit inlining across translation units to reduce binary size
KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
-# Check for frame size exceeding threshold during prolog/epilog insertion
-# when using lld < 13.0.0.
-ifneq ($(CONFIG_FRAME_WARN),0)
-ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
-KBUILD_LDFLAGS += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
-endif
-endif
-endif
-
ifdef CONFIG_LTO
KBUILD_CFLAGS += -fno-lto $(CC_FLAGS_LTO)
KBUILD_AFLAGS += -fno-lto
@@ -18,18 +18,12 @@ static __always_inline __attribute_const__ struct task_struct *get_current(void)
{
struct task_struct *cur;
-#if __has_builtin(__builtin_thread_pointer) && \
- defined(CONFIG_CURRENT_POINTER_IN_TPIDRURO) && \
- !(defined(CONFIG_THUMB2_KERNEL) && \
- defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 130001)
+#if __has_builtin(__builtin_thread_pointer) && defined(CONFIG_CURRENT_POINTER_IN_TPIDRURO)
/*
* Use the __builtin helper when available - this results in better
* code, especially when using GCC in combination with the per-task
* stack protector, as the compiler will recognize that it needs to
* load the TLS register only once in every function.
- *
- * Clang < 13.0.1 gets this wrong for Thumb2 builds:
- * https://github.com/ClangBuiltLinux/linux/issues/1485
*/
cur = __builtin_thread_pointer();
#elif defined(CONFIG_CURRENT_POINTER_IN_TPIDRURO) || defined(CONFIG_SMP)
@@ -382,7 +382,7 @@ config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
bool
# Clang's __builtin_return_adddress() strips the PAC since 12.0.0
# https://reviews.llvm.org/D75044
- default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
+ default y if CC_IS_CLANG
# GCC's __builtin_return_address() strips the PAC since 11.1.0,
# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
@@ -1368,7 +1368,6 @@ choice
config CPU_BIG_ENDIAN
bool "Build big-endian kernel"
- depends on !LD_IS_LLD || LLD_VERSION >= 130000
# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
depends on AS_IS_GNU || AS_VERSION >= 150000
help
@@ -1999,8 +1998,6 @@ config ARM64_BTI_KERNEL
depends on !CC_IS_GCC || GCC_VERSION >= 100100
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
depends on !CC_IS_GCC
- # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
- depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
help
Build the kernel with Branch Target Identification annotations
@@ -333,7 +333,6 @@ config PANIC_TIMEOUT
config COMPAT
bool "Enable support for 32bit binaries"
depends on PPC64
- depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
default y if !CPU_LITTLE_ENDIAN
select ARCH_WANT_OLD_COMPAT_IPC
select COMPAT_OLD_SIGACTION
@@ -167,8 +167,6 @@ config RISCV
config CLANG_SUPPORTS_DYNAMIC_FTRACE
def_bool CC_IS_CLANG
- # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e
- depends on CLANG_VERSION >= 130000
# https://github.com/ClangBuiltLinux/linux/issues/1817
depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
@@ -13,19 +13,9 @@
#endif
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
-/*
- * Clang prior to 13 had "mcount" instead of "_mcount":
- * https://reviews.llvm.org/D98881
- */
-#if defined(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 130000
-#define MCOUNT_NAME _mcount
-#else
-#define MCOUNT_NAME mcount
-#endif
-
#define ARCH_SUPPORTS_FTRACE_OPS 1
#ifndef __ASSEMBLY__
-void MCOUNT_NAME(void);
+void _mcount(void);
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
return addr;
@@ -75,7 +65,7 @@ struct dyn_arch_ftrace {
* both auipc and jalr at the same time.
*/
-#define MCOUNT_ADDR ((unsigned long)MCOUNT_NAME)
+#define MCOUNT_ADDR ((unsigned long)_mcount)
#define JALR_SIGN_MASK (0x00000800)
#define JALR_OFFSET_MASK (0x00000fff)
#define AUIPC_OFFSET_MASK (0xfffff000)
@@ -50,8 +50,8 @@
SYM_TYPED_FUNC_START(ftrace_stub)
#ifdef CONFIG_DYNAMIC_FTRACE
- .global MCOUNT_NAME
- .set MCOUNT_NAME, ftrace_stub
+ .global _mcount
+ .set _mcount, ftrace_stub
#endif
ret
SYM_FUNC_END(ftrace_stub)
@@ -80,7 +80,7 @@ SYM_FUNC_END(return_to_handler)
#endif
#ifndef CONFIG_DYNAMIC_FTRACE
-SYM_FUNC_START(MCOUNT_NAME)
+SYM_FUNC_START(_mcount)
la t4, ftrace_stub
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
la t0, ftrace_graph_return
@@ -126,6 +126,6 @@ SYM_FUNC_START(MCOUNT_NAME)
jalr t5
RESTORE_ABI_STATE
ret
-SYM_FUNC_END(MCOUNT_NAME)
+SYM_FUNC_END(_mcount)
#endif
-EXPORT_SYMBOL(MCOUNT_NAME)
+EXPORT_SYMBOL(_mcount)
@@ -217,12 +217,6 @@ endif
KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE)
-ifdef CONFIG_LTO_CLANG
-ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
-KBUILD_LDFLAGS += -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8)
-endif
-endif
-
ifdef CONFIG_X86_NEED_RELOCS
LDFLAGS_vmlinux := --emit-relocs --discard-none
else
@@ -114,11 +114,7 @@
#define __diag_str(s) __diag_str1(s)
#define __diag(s) _Pragma(__diag_str(clang diagnostic s))
-#if CONFIG_CLANG_VERSION >= 110000
-#define __diag_clang_11(s) __diag(s)
-#else
-#define __diag_clang_11(s)
-#endif
+#define __diag_clang_13(s) __diag(s)
#define __diag_ignore_all(option, comment) \
- __diag_clang(11, ignore, option)
+ __diag_clang(13, ignore, option)
@@ -2081,7 +2081,7 @@ config KCOV
depends on ARCH_HAS_KCOV
depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
- GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
+ GCC_VERSION >= 120000 || CC_IS_CLANG
select DEBUG_FS
select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
select OBJTOOL if HAVE_NOINSTR_HACK
@@ -27,7 +27,7 @@ llvm)
if [ "$SRCARCH" = s390 ]; then
echo 15.0.0
else
- echo 11.0.0
+ echo 13.0.1
fi
;;
rustc)
@@ -359,7 +359,7 @@ if ($arch eq "x86_64") {
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
} elsif ($arch eq "riscv") {
$function_regex = "^([0-9a-fA-F]+)\\s+<([^.0-9][0-9a-zA-Z_\\.]+)>:";
- $mcount_regex = "^\\s*([0-9a-fA-F]+):\\sR_RISCV_CALL(_PLT)?\\s_?mcount\$";
+ $mcount_regex = "^\\s*([0-9a-fA-F]+):\\sR_RISCV_CALL(_PLT)?\\s_mcount\$";
$type = ".quad";
$alignment = 2;
} elsif ($arch eq "csky") {
@@ -142,8 +142,6 @@ config HARDENED_USERCOPY
config FORTIFY_SOURCE
bool "Harden common str/mem functions against buffer overflows"
depends on ARCH_HAS_FORTIFY_SOURCE
- # https://bugs.llvm.org/show_bug.cgi?id=41459
- depends on !CC_IS_CLANG || CLANG_VERSION >= 120001
# https://github.com/llvm/llvm-project/issues/53645
depends on !CC_IS_CLANG || !X86_32
help
Hi all, It has been some time since we have bumped the minimum supported version of LLVM for building the kernel, the last time being commit df05c0e9496c ("Documentation: Raise the minimum supported version of LLVM to 11.0.0") in November of 2021. While I think we have done a pretty good job around supporting the current range of LLVM versions, it may be worth considering bumping the minimum supported version to 13.0.1 for a few reasons: 1. It would immediately resolve the massive build breakage with LLVM 11 in -next: https://github.com/ClangBuiltLinux/linux/issues/1958#issuecomment-1836559075 2. It would immediately save us almost 1300 builds per week with our current CI matrix, as we would be able to drop mainline and -next, which are our most frequently built trees. 3. It allows us to drop a good number of Kconfig and source workarounds. I have included a sample diff below. The downside of upgrading the minimum version is leaving distributions that have an older clang version behind. However, based on examining Docker images for the currently supported versions of the big distributions, I do not believe this upgrade should impact distribution support too much. archlinux:latest clang version 16.0.6 debian:oldoldstable-slim clang version 7.0.1-8+deb10u2 (tags/RELEASE_701/final) debian:oldstable-slim Debian clang version 11.0.1-2 debian:stable-slim Debian clang version 14.0.6 debian:testing-slim Debian clang version 16.0.6 (19) debian:unstable-slim Debian clang version 16.0.6 (19) fedora:38 clang version 16.0.6 (Fedora 16.0.6-3.fc38) fedora:latest clang version 17.0.6 (Fedora 17.0.6-1.fc39) fedora:rawhide clang version 17.0.6 (Fedora 17.0.6-1.fc40) opensuse/leap:latest clang version 15.0.7 opensuse/tumbleweed:latest clang version 17.0.6 ubuntu:focal clang version 10.0.0-4ubuntu1 ubuntu:latest Ubuntu clang version 14.0.0-1ubuntu1.1 ubuntu:rolling Ubuntu clang version 16.0.6 (15) ubuntu:devel Ubuntu clang version 17.0.6 (3) As we can see, the only distribution in that list that would be impacted by this change would be Debian Bullseye (oldstable), as its clang version in the default repositories is 11.0.1. Other distributions that have a clang older than 11.0.1 already cannot build the upstream kernel. In Debian's case, access to newer versions of LLVM is relatively simple because of https://apt.llvm.org. There is also the kernel.org LLVM toolchains I publish: https://mirrors.edge.kernel.org/pub/tools/llvm/ Thoughts or concerns? I have posted this on GitHub as well in case people want to chime in there instead of here for some reason: https://github.com/ClangBuiltLinux/linux/issues/1975 Cheers, Nathan