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 500C1C00144 for ; Mon, 1 Aug 2022 19:04:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233655AbiHATE5 (ORCPT ); Mon, 1 Aug 2022 15:04:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233346AbiHATEW (ORCPT ); Mon, 1 Aug 2022 15:04:22 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8F83402DD; Mon, 1 Aug 2022 12:03:11 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 6379961223; Mon, 1 Aug 2022 19:03:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BF74C433D7; Mon, 1 Aug 2022 19:03:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659380587; bh=uJHMEQ/p9vxDrf88lSYBSMdt4WRsz6QhQJuyXjLLLfo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BUlJw9kxgj0ZowVNvEM7XpB08i66IlUZUW92AzhW1RYR7YV9lnfRdhqv63RCe8l4f 6pJTl7gEfBZBet2Ekmv+Kgx7vdYvfnWi7qZk4PuxXUufQETqSalT2PxJOaGVJjei3C sJYdpH37G9FLGItTqEwXIuF5f9UN3pzGppd8R4+vRxglRrbxMc0phDTEbPD+RHO8Ae 8Wy0B2ibcsKK0XoTTRzwoiI83QvJphCutd4gUyiu+1rFuFymi15PGXzDQZkuBP5rT5 xbBnH95Jb9wX0Kt0pPN7zA+R6C9Nsx2KBtQ4nM6HIqGnrYFm16Mjyd9jLVYLjyY0bS 8D7LWOFQYjsGg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Michael Ellerman , Sudip Mukherjee , Sasha Levin , christophe.leroy@csgroup.eu, paulus@ozlabs.org, peterz@infradead.org, ast@kernel.org, npiggin@gmail.com, dja@axtens.net, masahiroy@kernel.org, aneesh.kumar@linux.ibm.com, linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.10 2/7] powerpc/64s: Disable stack variable initialisation for prom_init Date: Mon, 1 Aug 2022 15:02:56 -0400 Message-Id: <20220801190301.3819065-2-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220801190301.3819065-1-sashal@kernel.org> References: <20220801190301.3819065-1-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 376104c166fc..db2bdc4cec64 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