From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E8C9C3FCC for ; Tue, 28 Sep 2021 15:42:28 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 11AB061354; Tue, 28 Sep 2021 15:42:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632843748; bh=Kjod7Dg1Idecfo4RpcY/AygTGl3Rik7I7C/y/vFeIAI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TnEhddhDpbfT/qGh4mtxDa35mWR0KNstAx/Tk7QCXEL3tXbJ5M6tj3cCGu7g4qU2b t218VqoaMedlmVE49FLfg0Wd/f59Jyc7RF2zYT2kw0er+0btGRV8r5LsQqLHGKgd4X iUDIAo3muUgv2mnHi/hG8bGek5du5hZF0UjuIgvSQQnFB6bC9/TDGcDBVIW4B+7XgH 8EMSrKFsC9GpSqLsSCv6/I2Cc1zk3EDC0KCZYXxWT+fKulgSioc5jtgLyiKUsfikjg eVf6Bt5LcduS1IGmb0bcdkpPN3DSXhiI234za3TutW2EfApV99fvH/U03+G0LqWSwC DTI5FVY5du/8g== From: Arnd Bergmann To: Russell King Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Arnd Bergmann , Ard Biesheuvel , Linus Walleij , Nathan Chancellor , Nick Desaulniers , llvm@lists.linux.dev Subject: [PATCH 14/14] [RFC] ARM: forbid ftrace with clang and thumb2_kernel Date: Tue, 28 Sep 2021 17:41:43 +0200 Message-Id: <20210928154143.2106903-15-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210928154143.2106903-1-arnd@kernel.org> References: <20210928154143.2106903-1-arnd@kernel.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnd Bergmann clang fails to build kernels with THUMB2 and FUNCTION_TRACER enabled when there is any inline asm statement containing the frame pointer register r7: arch/arm/mach-versatile/dcscb.c:95:2: error: inline asm clobber list contains reserved registers: R7 [-Werror,-Winline-asm] arch/arm/mach-exynos/mcpm-exynos.c:154:2: error: inline asm clobber list contains reserved registers: R7 [-Werror,-Winline-asm] arch/arm/probes/kprobes/actions-thumb.c:449:3: error: inline asm clobber list contains reserved registers: R7 [-Werror,-Winline-asm] Apparently gcc should also have warned about this, and the configuration is actually invalid, though there is some disagreement on the bug trackers about this. Link: https://bugs.llvm.org/show_bug.cgi?id=45826 Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94986 Signed-off-by: Arnd Bergmann --- arch/arm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 0d4f3e2d50ad..7ea95bb40004 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -91,7 +91,7 @@ config ARM select HAVE_FAST_GUP if ARM_LPAE select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG - select HAVE_FUNCTION_TRACER if !XIP_KERNEL + select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !(THUMB2_KERNEL && CC_IS_CLANG) select HAVE_GCC_PLUGINS select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) select HAVE_IRQ_TIME_ACCOUNTING -- 2.29.2