[PATCH 04/11] ARM: Remove Thumb2 __builtin_thread_pointer workaround for Clang

[Nathan Chancellor]

Now that the minimum supported version of LLVM for building the kernel
has been bumped to 13.0.1, the conditional expression added to
get_current() by commit c1e42efacb9b ("ARM: 9151/1: Thumb2: avoid
__builtin_thread_pointer() on Clang") is always true, as the build will
fail during the configuration stage for older LLVM versions. Remove it,
effectively reverting the aforementioned change.

Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---
Cc: linux@xxxxxxxxxxxxxxx
Cc: ardb@xxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
---
 arch/arm/include/asm/current.h | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

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)

-- 
2.43.0