[RFC] Bumping the minimum supported version of LLVM to 13.0.1

diff --git a/Makefile b/Makefile
index f1b2fd977275..32f42f4470ec 100644
--- a/Makefile
+++ b/Makefile
@@ -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
diff --git a/arch/arm/include/asm/current.h b/arch/arm/include/asm/current.h
index 1e1178bf176d..5225cb1c803b 100644
--- a/arch/arm/include/asm/current.h
+++ b/arch/arm/include/asm/current.h
@@ -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)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 8f6cf1221b6a..576c203fc2b7 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -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
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 414b978b8010..58ab1e546c98 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -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
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index cd4c9a204d08..6dc601dc6f06 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -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))
 
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
index 2b2f5df7ef2c..7113b010cf1f 100644
--- a/arch/riscv/include/asm/ftrace.h
+++ b/arch/riscv/include/asm/ftrace.h
@@ -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)
diff --git a/arch/riscv/kernel/mcount.S b/arch/riscv/kernel/mcount.S
index b4dd9ed6849e..da00fa3536c8 100644
--- a/arch/riscv/kernel/mcount.S
+++ b/arch/riscv/kernel/mcount.S
@@ -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)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 1a068de12a56..de30a8b35c41 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -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
diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
index ddab1ef22bee..e7633723dad6 100644
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -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)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 97ce28f4d154..6919f0e5fb46 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -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
diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
index fd5ffdb81bab..d48bd9c87c7b 100755
--- a/scripts/min-tool-version.sh
+++ b/scripts/min-tool-version.sh
@@ -27,7 +27,7 @@  llvm)
 	if [ "$SRCARCH" = s390 ]; then
 		echo 15.0.0
 	else
-		echo 11.0.0
+		echo 13.0.1
 	fi
 	;;
 rustc)
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 6a4645a57976..5794b3a43137 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -359,7 +359,7 @@  if ($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") {
diff --git a/security/Kconfig b/security/Kconfig
index 52c9af08ad35..412e76f1575d 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -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