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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 346ABC00144 for ; Mon, 1 Aug 2022 19:02:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233535AbiHATCo (ORCPT ); Mon, 1 Aug 2022 15:02:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232741AbiHATCh (ORCPT ); Mon, 1 Aug 2022 15:02:37 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9865D2BB3E; Mon, 1 Aug 2022 12:02:35 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 04B7BB81616; Mon, 1 Aug 2022 19:02:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 624A3C433D6; Mon, 1 Aug 2022 19:02:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659380552; bh=8TuZYBANaANy8tBI2NDEhOSwYzvW/85ai8F71UZsmK0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ee7sS+WjoKsphXm66prEadyQX1DQgMBZO1yMuoKsg6JsJdFBn7zgDeBDDoMeny9S3 Vc+qqsVb2sX+q/6wcgD3dA1vhXPagwHjH0/7fHeu+T4HznDsUqJGu/UvZa+eBQo/Sz uLmHke+6xZjCfAwZZ0+7eTn+GeE9aAFJIbBdGTj22J7HivLtZbheHphFLgVU5DXgGo WVZi107lIHUjT0Mn3c70laXxR8Wltjys+ddE7HqIJyhm7yJf93jaOCJSf6ftwYfDfu O+f3tq7iogbHnLFCKnEfXpB5alNEuN8luqlXTsxCxWaaRBOVibmAXN0t3KbqTFh4Y6 10FM5iORe/t+g== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Michael Ellerman , Sudip Mukherjee , Sasha Levin , christophe.leroy@csgroup.eu, ast@kernel.org, peterz@infradead.org, paulus@ozlabs.org, npiggin@gmail.com, dja@axtens.net, masahiroy@kernel.org, aneesh.kumar@linux.ibm.com, linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.18 04/10] powerpc/64s: Disable stack variable initialisation for prom_init Date: Mon, 1 Aug 2022 15:02:16 -0400 Message-Id: <20220801190222.3818378-4-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220801190222.3818378-1-sashal@kernel.org> References: <20220801190222.3818378-1-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: Michael Ellerman [ Upstream commit be640317a1d0b9cf42fedb2debc2887a7cfa38de ] With GCC 12 allmodconfig prom_init fails to build: Error: External symbol 'memset' referenced from prom_init.c make[2]: *** [arch/powerpc/kernel/Makefile:204: arch/powerpc/kernel/prom_init_check] Error 1 The allmodconfig build enables KASAN, so all calls to memset in prom_init should be converted to __memset by the #ifdefs in asm/string.h, because prom_init must use the non-KASAN instrumented versions. The build failure happens because there's a call to memset that hasn't been caught by the pre-processor and converted to __memset. Typically that's because it's a memset generated by the compiler itself, and that is the case here. With GCC 12, allmodconfig enables CONFIG_INIT_STACK_ALL_PATTERN, which causes the compiler to emit memset calls to initialise on-stack variables with a pattern. Because prom_init is non-user-facing boot-time only code, as a workaround just disable stack variable initialisation to unbreak the build. Reported-by: Sudip Mukherjee Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220718134418.354114-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin --- arch/powerpc/kernel/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 4ddd161aef32..63c384c3e6d4 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -20,6 +20,7 @@ CFLAGS_prom.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) CFLAGS_prom_init.o += -fno-stack-protector CFLAGS_prom_init.o += -DDISABLE_BRANCH_PROFILING CFLAGS_prom_init.o += -ffreestanding +CFLAGS_prom_init.o += $(call cc-option, -ftrivial-auto-var-init=uninitialized) ifdef CONFIG_FUNCTION_TRACER # Do not trace early boot code -- 2.35.1