From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 185911FB9 for ; Fri, 3 Feb 2023 10:22:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F7E7C4339B; Fri, 3 Feb 2023 10:22:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675419727; bh=xL6mj3in65YLENSDB9HU2mlwGRdqZQ1tv1ig7iJgYqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FBCGmRNNzm6lPVa1bxJr6zm8NCOaegzw9gW3JTN59d8eEasIwNkHjCLNRi56S5T71 gBlKw97l7xfJZ+3jRXXPnBRGpyTeNHRhDLh88tqwxilVkDp4/O2lNlw725z9QwptMr yV217EEMBtlPZI1LzkuxiMb7TAoUhSqomV0ByW4o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Geert Uytterhoeven , Heiko Carstens , Sasha Levin Subject: [PATCH 6.1 17/28] s390: workaround invalid gcc-11 out of bounds read warning Date: Fri, 3 Feb 2023 11:13:05 +0100 Message-Id: <20230203101010.708423717@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230203101009.946745030@linuxfoundation.org> References: <20230203101009.946745030@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Heiko Carstens [ Upstream commit 41e1992665a2701fa025a8b76970c43b4148446f ] GCC 11.1.0 and 11.2.0 generate a wrong warning when compiling the kernel e.g. with allmodconfig: arch/s390/kernel/setup.c: In function ‘setup_lowcore_dat_on’: ./include/linux/fortify-string.h:57:33: error: ‘__builtin_memcpy’ reading 128 bytes from a region of size 0 [-Werror=stringop-overread] ... arch/s390/kernel/setup.c:526:9: note: in expansion of macro ‘memcpy’ 526 | memcpy(abs_lc->cregs_save_area, S390_lowcore.cregs_save_area, | ^~~~~~ This could be addressed by using absolute_pointer() with the S390_lowcore macro, but this is not a good idea since this generates worse code for performance critical paths. Therefore simply use a for loop to copy the array in question and get rid of the warning. Reported-by: Geert Uytterhoeven Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- arch/s390/kernel/setup.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index ab19ddb09d65..2ec5f1e0312f 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -507,6 +507,7 @@ static void __init setup_lowcore_dat_on(void) { struct lowcore *abs_lc; unsigned long flags; + int i; __ctl_clear_bit(0, 28); S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT; @@ -521,8 +522,8 @@ static void __init setup_lowcore_dat_on(void) abs_lc = get_abs_lowcore(&flags); abs_lc->restart_flags = RESTART_FLAG_CTLREGS; abs_lc->program_new_psw = S390_lowcore.program_new_psw; - memcpy(abs_lc->cregs_save_area, S390_lowcore.cregs_save_area, - sizeof(abs_lc->cregs_save_area)); + for (i = 0; i < 16; i++) + abs_lc->cregs_save_area[i] = S390_lowcore.cregs_save_area[i]; put_abs_lowcore(abs_lc, flags); } -- 2.39.0