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From: Nathan Chancellor <nathan@kernel.org>
To: akpm@linux-foundation.org, masahiroy@kernel.org
Cc: nicolas@fjasle.eu, linux-kbuild@vger.kernel.org,
	llvm@lists.linux.dev,  patches@lists.linux.dev,
	linux-kernel@vger.kernel.org,
	 Nathan Chancellor <nathan@kernel.org>,
	linux@armlinux.org.uk,  ardb@kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 04/11] ARM: Remove Thumb2 __builtin_thread_pointer workaround for Clang
Date: Thu, 25 Jan 2024 15:55:10 -0700	[thread overview]
Message-ID: <20240125-bump-min-llvm-ver-to-13-0-1-v1-4-f5ff9bda41c5@kernel.org> (raw)
In-Reply-To: <20240125-bump-min-llvm-ver-to-13-0-1-v1-0-f5ff9bda41c5@kernel.org>

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@kernel.org>
---
Cc: linux@armlinux.org.uk
Cc: ardb@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
---
 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


  parent reply	other threads:[~2024-01-25 22:56 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-25 22:55 [PATCH 00/11] Bump the minimum supported version of LLVM to 13.0.1 Nathan Chancellor
2024-01-25 22:55 ` [PATCH 01/11] kbuild: Raise " Nathan Chancellor
2024-01-25 22:55 ` [PATCH 02/11] Makefile: Drop warn-stack-size plugin opt Nathan Chancellor
2024-01-25 22:55 ` [PATCH 03/11] x86: Drop stack-alignment " Nathan Chancellor
2024-01-25 22:55 ` Nathan Chancellor [this message]
2024-01-26  8:44   ` [PATCH 04/11] ARM: Remove Thumb2 __builtin_thread_pointer workaround for Clang Ard Biesheuvel
2024-01-25 22:55 ` [PATCH 05/11] arm64: Kconfig: Clean up tautological LLVM version checks Nathan Chancellor
2024-01-26 12:59   ` Mark Rutland
2024-01-26 16:10     ` Nathan Chancellor
2024-01-26 17:00       ` Mark Rutland
2024-01-25 22:55 ` [PATCH 06/11] powerpc: Kconfig: Remove tautology in CONFIG_COMPAT Nathan Chancellor
2024-01-25 22:55 ` [PATCH 07/11] riscv: Remove MCOUNT_NAME workaround Nathan Chancellor
2024-01-25 22:55 ` [PATCH 08/11] riscv: Kconfig: Remove version dependency from CONFIG_CLANG_SUPPORTS_DYNAMIC_FTRACE Nathan Chancellor
2024-01-25 22:55 ` [PATCH 09/11] fortify: Drop Clang version check for 12.0.1 or newer Nathan Chancellor
2024-01-25 23:09   ` Kees Cook
2024-01-25 22:55 ` [PATCH 10/11] lib/Kconfig.debug: Update Clang version check in CONFIG_KCOV Nathan Chancellor
2024-01-25 22:55 ` [PATCH 11/11] compiler-clang.h: Update __diag_clang() macros for minimum version bump Nathan Chancellor
2024-01-25 23:10 ` [PATCH 00/11] Bump the minimum supported version of LLVM to 13.0.1 Kees Cook
2024-03-25  4:42 ` patchwork-bot+linux-riscv

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