From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751221AbeBTWAT (ORCPT ); Tue, 20 Feb 2018 17:00:19 -0500 Received: from mout.kundenserver.de ([217.72.192.74]:50007 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750735AbeBTWAS (ORCPT ); Tue, 20 Feb 2018 17:00:18 -0500 From: Arnd Bergmann To: Nicolas Pitre Cc: Andi Kleen , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Arnd Bergmann Subject: [PATCH 2/7] ARM: LTO: avoid THUMB2_KERNEL+LTO Date: Tue, 20 Feb 2018 22:59:49 +0100 Message-Id: <20180220215954.4092811-3-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20180220215954.4092811-1-arnd@arndb.de> References: <20180220215954.4092811-1-arnd@arndb.de> X-Provags-ID: V03:K0:u3KJWzqET9ns5Lg+m/MiDFxCNf+0k3MQUUUfTn6++ORQZePXN1j mi6mz90RJHWy+PVhAkmNYeriJ35b4438nHM6SFXwhRhgsyXBB96WYGpwm3QP2TEatBilBtx IAk8ErVh57EmlAbnHvtWBTTKfMwUJ6jXq0i/gjvgIhsnhQy1UZ2TMUr7fytlRBnhbH60/zW p8KUauJSv6ARo5IvkBcuw== X-UI-Out-Filterresults: notjunk:1;V01:K0:lq2vHQPEv3M=:5SSk4VkGusr2hEy+y4tCo3 eTpGu9WiFscv9HdHREs8x0QHu5x0jy/xu3meN1t+p4LeX000RpuTf23cyvUIp9ibKnqYK8B2q jSdGvNhJpmFjIzraWeeev6C8Y6YfWP4Jv+gA7DM6FxfV/RRjG9E1Ohs3WCqwPTuAyOUZxjg+t HzudzChvronAoGTK9P8cBSygtoZNqZUb4MTPQiCPOk9hXH1m4n8tNYX8Bx+Ts7hOeF0whtDPw 4btdT87XipB+CIL/zLclhSTzN0vImmD8wnzQCtNRr7ijuitfbnykLWd5HroZQC3H0Bg8htsQL H+vsfKpZYAc/FCj2+ICIHNk9LKfjM/gdxylM3ex4QR28AKVQiXqXnvz4w7a8yXdtBJl/Q/U1q XeIUeYM3ygLyS8pzt3ELvplVHCLdRxtap9s89yHJdoGNwddES+RlcVFZFtSirOINeSq67+L3n TJdbvy+iJ26nVcF6IpcRXrDWeE6FwwO1JmOUVBBvtEIS2EA5h2eqyVzv1a90DSTpeKb9r5X26 C39dbtdxmoIxX24WTuZpWVyhXruDUeOZ8FUtn2HiHOnHUFGiQ+kAHdR8XQUoUXR5zcEHXc7rf llH0nCtFeOvORdyHS5+TKSwR6J4kkwrJ5vgRd4znffaF12JtHl6Jt1zhC8g9kIWWIVT8cuvZL scppz2aNVch0hVvKBqzPn9T3wtVM9SAVy1o/+Y4OhWwRnd9Ik+tyPmt25ZEYZBMu9PRxVT7zd wS0eSnUaP6KWOdsq8K+dGUUy4s9VIN1mxoFWpQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Trying to build an LTO-Enabled kernel with Thumb2 instructions failed horribly for me, with an endless output of things like ccVnNycO.s:2665: Error: thumb conditional instruction should be in IT block -- `bxne lr' ccVnNycO.s:7128: Error: thumb conditional instruction should be in IT block -- `strexeq r5,r2,[r3]' ccVnNycO.s:7258: Error: thumb conditional instruction should be in IT block -- `strexeq lr,r0,[r3]' ccVnNycO.s:17380: Error: thumb conditional instruction should be in IT block -- `strexeq r1,r2,[r6]' ccVnNycO.s:19163: Error: thumb conditional instruction should be in IT block -- `strexeq r8,r6,[r3]' ccVnNycO.s:22722: Error: thumb conditional instruction should be in IT block -- `strexeq r7,r1,[r0]' ccVnNycO.s:24105: conditional infixes are deprecated in unified syntax ccVnNycO.s:24105: Error: thumb conditional instruction should be in IT block -- `sbcccs r1,r1,r3' ccVnNycO.s:24105: Error: thumb conditional instruction should be in IT block -- `movcc r3,#0' ccVnNycO.s:24210: conditional infixes are deprecated in unified syntax ccVnNycO.s:24210: Error: thumb conditional instruction should be in IT block -- `sbcccs r2,r2,r3' ccVnNycO.s:24210: Error: thumb conditional instruction should be in IT block -- `movcc r3,#0' I did not investigate this too much, disabling Thumb2 support when LTO is set lets me build randconfig kernels. Since ARM_SINGLE_ARMV7M is Thumb2-only, I have to disallow LTO for V7-M targets. Signed-off-by: Arnd Bergmann --- arch/arm/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 8ed0f664f86f..fbf2c3ab9a97 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -18,7 +18,7 @@ config ARM select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7 select ARCH_SUPPORTS_ATOMIC_RMW - select ARCH_SUPPORTS_LTO + select ARCH_SUPPORTS_LTO if !ARM_SINGLE_ARMV7M select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF select ARCH_WANT_IPC_PARSE_VERSION @@ -1533,6 +1533,7 @@ config SCHED_HRTICK config THUMB2_KERNEL bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K + depends on !LTO default y if CPU_THUMBONLY select ARM_UNWIND help -- 2.9.0