From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46256 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757403AbeD0FhD (ORCPT ); Fri, 27 Apr 2018 01:37:03 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w3R5YeQI098336 for ; Fri, 27 Apr 2018 01:37:03 -0400 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 2hkwdngycr-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 27 Apr 2018 01:37:02 -0400 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 27 Apr 2018 06:37:00 +0100 From: Martin Schwidefsky To: Greg Kroah-Hartman , stable@vger.kernel.org Cc: Martin Schwidefsky Subject: [PATCH 18/19] s390: correct nospec auto detection init order Date: Fri, 27 Apr 2018 07:36:56 +0200 In-Reply-To: <20180427053657.56944-1-schwidefsky@de.ibm.com> References: <20180427053657.56944-1-schwidefsky@de.ibm.com> Message-Id: <20180427053657.56944-19-schwidefsky@de.ibm.com> Sender: stable-owner@vger.kernel.org List-ID: [ Upstream commit 6a3d1e81a434fc311f224b8be77258bafc18ccc6 ] With CONFIG_EXPOLINE_AUTO=y the call of spectre_v2_auto_early() via early_initcall is done *after* the early_param functions. This overwrites any settings done with the nobp/no_spectre_v2/spectre_v2 parameters. The code patching for the kernel is done after the evaluation of the early parameters but before the early_initcall is done. The end result is a kernel image that is patched correctly but the kernel modules are not. Make sure that the nospec auto detection function is called before the early parameters are evaluated and before the code patching is done. Fixes: 6e179d64126b ("s390: add automatic detection of the spectre defense") Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/nospec-branch.h | 1 + arch/s390/kernel/nospec-branch.c | 8 ++------ arch/s390/kernel/setup.c | 3 +++ 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/s390/include/asm/nospec-branch.h b/arch/s390/include/asm/nospec-branch.h index 35bf28fe4c64..b4bd8c41e9d3 100644 --- a/arch/s390/include/asm/nospec-branch.h +++ b/arch/s390/include/asm/nospec-branch.h @@ -9,6 +9,7 @@ extern int nospec_disable; void nospec_init_branches(void); +void nospec_auto_detect(void); void nospec_revert(s32 *start, s32 *end); #endif /* __ASSEMBLY__ */ diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c index 73c06d42792d..9f3b5b382743 100644 --- a/arch/s390/kernel/nospec-branch.c +++ b/arch/s390/kernel/nospec-branch.c @@ -73,7 +73,7 @@ static int __init nospectre_v2_setup_early(char *str) } early_param("nospectre_v2", nospectre_v2_setup_early); -static int __init spectre_v2_auto_early(void) +void __init nospec_auto_detect(void) { if (IS_ENABLED(CC_USING_EXPOLINE)) { /* @@ -88,11 +88,7 @@ static int __init spectre_v2_auto_early(void) * nobp setting decides what is done, this depends on the * CONFIG_KERNEL_NP option and the nobp/nospec parameters. */ - return 0; } -#ifdef CONFIG_EXPOLINE_AUTO -early_initcall(spectre_v2_auto_early); -#endif static int __init spectre_v2_setup_early(char *str) { @@ -103,7 +99,7 @@ static int __init spectre_v2_setup_early(char *str) if (str && !strncmp(str, "off", 3)) nospec_disable = 1; if (str && !strncmp(str, "auto", 4)) - spectre_v2_auto_early(); + nospec_auto_detect(); return 0; } early_param("spectre_v2", spectre_v2_setup_early); diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index bc25366f0244..feb9d97a9d14 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -876,6 +876,9 @@ void __init setup_arch(char **cmdline_p) init_mm.end_data = (unsigned long) &_edata; init_mm.brk = (unsigned long) &_end; + if (IS_ENABLED(CONFIG_EXPOLINE_AUTO)) + nospec_auto_detect(); + parse_early_param(); #ifdef CONFIG_CRASH_DUMP /* Deactivate elfcorehdr= kernel parameter */ -- 2.13.5