Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3E50C54E94 for ; Mon, 23 Jan 2023 13:46:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231905AbjAWNqa (ORCPT ); Mon, 23 Jan 2023 08:46:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231821AbjAWNqW (ORCPT ); Mon, 23 Jan 2023 08:46:22 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4013EEFB9; Mon, 23 Jan 2023 05:46:20 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AF6FC150C; Mon, 23 Jan 2023 05:47:01 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 250473F64C; Mon, 23 Jan 2023 05:46:18 -0800 (PST) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, mhiramat@kernel.org, ndesaulniers@google.com, ojeda@kernel.org, peterz@infradead.org, rafael.j.wysocki@intel.com, revest@chromium.org, robert.moore@intel.com, rostedt@goodmis.org, will@kernel.org Subject: [PATCH v3 3/8] ACPI: Don't build ACPICA with '-Os' Date: Mon, 23 Jan 2023 13:45:58 +0000 Message-Id: <20230123134603.1064407-4-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230123134603.1064407-1-mark.rutland@arm.com> References: <20230123134603.1064407-1-mark.rutland@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The ACPICA code has been built with '-Os' since the beginning of git history, though there's no explanatory comment as to why. This is unfortunate as GCC drops the alignment specificed by '-falign-functions=N' when '-Os' is used, as reported in GCC bug 88345: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345 This prevents CONFIG_FUNCTION_ALIGNMENT and CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B from having their expected effect on the ACPICA code. This is doubly unfortunate as in subsequent patches arm64 will depend upon CONFIG_FUNCTION_ALIGNMENT for its ftrace implementation. Drop the '-Os' flag when building the ACPICA code. With this removed, the code builds cleanly and works correctly in testing so far. I've tested this by selecting CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B=y, building and booting a kernel using ACPI, and looking for misaligned text symbols: * arm64: Before, v6.2-rc3: # uname -rm 6.2.0-rc3 aarch64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 5009 Before, v6.2-rc3 + fixed __cold: # uname -rm 6.2.0-rc3-00001-g2a2bedf8bfa9 aarch64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 919 After: # uname -rm 6.2.0-rc3-00002-g267bddc38572 aarch64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 323 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | grep acpi | wc -l 0 * x86_64: Before, v6.2-rc3: # uname -rm 6.2.0-rc3 x86_64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 11537 Before, v6.2-rc3 + fixed __cold: # uname -rm 6.2.0-rc3-00001-g2a2bedf8bfa9 x86_64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 2805 After: # uname -rm 6.2.0-rc3-00002-g267bddc38572 x86_64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 1357 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | grep acpi | wc -l 0 With the patch applied, the remaining unaligned text labels are a combination of static call trampolines and labels in assembly, which can be dealt with in subsequent patches. Signed-off-by: Mark Rutland Acked-by: Rafael J. Wysocki Cc: Catalin Marinas Cc: Florent Revest Cc: Len Brown Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Robert Moore Cc: Steven Rostedt Cc: Will Deacon Cc: linux-acpi@vger.kernel.org --- drivers/acpi/acpica/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/acpica/Makefile b/drivers/acpi/acpica/Makefile index 9e0d95d76fff..30f3fc13c29d 100644 --- a/drivers/acpi/acpica/Makefile +++ b/drivers/acpi/acpica/Makefile @@ -3,7 +3,7 @@ # Makefile for ACPICA Core interpreter # -ccflags-y := -Os -D_LINUX -DBUILDING_ACPICA +ccflags-y := -D_LINUX -DBUILDING_ACPICA ccflags-$(CONFIG_ACPI_DEBUG) += -DACPI_DEBUG_OUTPUT # use acpi.o to put all files here into acpi.o modparam namespace -- 2.30.2