From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34122C433E6 for ; Mon, 8 Feb 2021 19:51:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECCA264E70 for ; Mon, 8 Feb 2021 19:51:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236377AbhBHTvP (ORCPT ); Mon, 8 Feb 2021 14:51:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:49422 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235429AbhBHSGU (ORCPT ); Mon, 8 Feb 2021 13:06:20 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 783B764EA4; Mon, 8 Feb 2021 18:00:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612807206; bh=yEz59mW/D8ynLyqG43it/6sgqSDIlQJ4NR3HDrCHwjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B4/prwKtdGEFnWKWILV6H32TIu7bJM6DSJVMujilTEeCCuKS9QLbWmpmN0VxV8oA7 87VeOn05+l9cb+oLu40c3R4wHZghdstwQUuEmwotmlaqrpFcTQxS7hw/qiQYFo9MX5 COCRlZOIa1SujwfV/dfftwaA+MxD4E/DwOY4lJcZuvES+w27FdUpvUnAyY2v6FoSid vhJ1epZ9CdhcGM/ny8Sp1BSvtGgRvY6m4d+INklVlkNCR6x96KIRxPXIBQf+lyjV7H gXSK3V7NaDWZNyu+WD6PhA1Kjgzi2RtepZnLyCCK/XMuDWdQKFVAK7qdZ7PsPoZ2Wq ipvEigiYf+uhw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Johannes Berg , Peter Oberparleiter , Arnd Bergmann , Jessica Yu , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 4.9 4/4] init/gcov: allow CONFIG_CONSTRUCTORS on UML to fix module gcov Date: Mon, 8 Feb 2021 13:00:00 -0500 Message-Id: <20210208180000.2092497-4-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210208180000.2092497-1-sashal@kernel.org> References: <20210208180000.2092497-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johannes Berg [ Upstream commit 55b6f763d8bcb5546997933105d66d3e6b080e6a ] On ARCH=um, loading a module doesn't result in its constructors getting called, which breaks module gcov since the debugfs files are never registered. On the other hand, in-kernel constructors have already been called by the dynamic linker, so we can't call them again. Get out of this conundrum by allowing CONFIG_CONSTRUCTORS to be selected, but avoiding the in-kernel constructor calls. Also remove the "if !UML" from GCOV selecting CONSTRUCTORS now, since we really do want CONSTRUCTORS, just not kernel binary ones. Link: https://lkml.kernel.org/r/20210120172041.c246a2cac2fb.I1358f584b76f1898373adfed77f4462c8705b736@changeid Signed-off-by: Johannes Berg Reviewed-by: Peter Oberparleiter Cc: Arnd Bergmann Cc: Jessica Yu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- init/Kconfig | 1 - init/main.c | 8 +++++++- kernel/gcov/Kconfig | 2 +- 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index 0a615bdc203a4..34fb7b8798aa7 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -18,7 +18,6 @@ config DEFCONFIG_LIST config CONSTRUCTORS bool - depends on !UML config IRQ_WORK bool diff --git a/init/main.c b/init/main.c index 7ad08957dd180..649220593244e 100644 --- a/init/main.c +++ b/init/main.c @@ -669,7 +669,13 @@ asmlinkage __visible void __init start_kernel(void) /* Call all constructor functions linked into the kernel. */ static void __init do_ctors(void) { -#ifdef CONFIG_CONSTRUCTORS +/* + * For UML, the constructors have already been called by the + * normal setup code as it's just a normal ELF binary, so we + * cannot do it again - but we do need CONFIG_CONSTRUCTORS + * even on UML for modules. + */ +#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; for (; fn < (ctor_fn_t *) __ctors_end; fn++) diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig index 1276aabaab550..2aef7d9e3e5c2 100644 --- a/kernel/gcov/Kconfig +++ b/kernel/gcov/Kconfig @@ -3,7 +3,7 @@ menu "GCOV-based kernel profiling" config GCOV_KERNEL bool "Enable gcov-based kernel profiling" depends on DEBUG_FS - select CONSTRUCTORS if !UML + select CONSTRUCTORS default n ---help--- This option enables gcov-based code profiling (e.g. for code coverage -- 2.27.0