From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: Re: [PATCH] ACPICA: use designated initializers Date: Fri, 31 Mar 2017 17:26:27 -0700 Message-ID: References: <20161217010425.GA140581@beast> <1AE640813FDE7649BE1B193DEA596E886CDFF348@SHSMSX101.ccr.corp.intel.com> <1AE640813FDE7649BE1B193DEA596E886CE6BD95@SHSMSX101.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-it0-f50.google.com ([209.85.214.50]:35947 "EHLO mail-it0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754944AbdDAA02 (ORCPT ); Fri, 31 Mar 2017 20:26:28 -0400 Received: by mail-it0-f50.google.com with SMTP id e75so21942542itd.1 for ; Fri, 31 Mar 2017 17:26:28 -0700 (PDT) In-Reply-To: <1AE640813FDE7649BE1B193DEA596E886CE6BD95@SHSMSX101.ccr.corp.intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Zheng, Lv" Cc: "linux-kernel@vger.kernel.org" , "Moore, Robert" , "Wysocki, Rafael J" , Len Brown , "linux-acpi@vger.kernel.org" , "devel@acpica.org" On Wed, Mar 29, 2017 at 7:12 PM, Zheng, Lv wrote: > Hi, > >> From: keescook@google.com [mailto:keescook@google.com] On Behalf Of Kees Cook >> Subject: Re: [PATCH] ACPICA: use designated initializers >> >> On Sun, Dec 18, 2016 at 10:06 PM, Zheng, Lv wrote: >> > Hi, >> > >> >> From: Kees Cook [mailto:keescook@chromium.org] >> >> Subject: [PATCH] ACPICA: use designated initializers >> >> >> >> Prepare to mark sensitive kernel structures for randomization by making >> >> sure they're using designated initializers. These were identified during >> >> allyesconfig builds of x86, arm, and arm64, with most initializer fixes >> >> extracted from grsecurity. >> > >> > This commit is not suitable for ACPICA upstream. >> > It's not portable. Please drop. >> >> What compilers are building this that do not support designated >> initializers? Also, couldn't this be made into a macro so it could be >> supported in either case? > > It's MSVC. > In ACPICA upstream, it supports Intel compiler, GCC and MSVC. > >> >> #ifdef __GNUC__ >> # define ACPI_SLEEP_FUNCTIONS(legacy, extended) { \ >> .legacy_function = legacy, \ >> .extended_function = extended, \ >> } >> #else >> # define ACPI_SLEEP_FUNCTIONS(legacy, extended) { legacy, extended } >> #endif >> >> ... >> >> static struct acpi_sleep_functions acpi_sleep_dispatch[] = { >> ACPI_SLEEP_FUNCTIONS( >> ACPI_HW_OPTIONAL_FUNCTION(acpi_hw_legacy_sleep), >> acpi_hw_extended_sleep), >> ... > > There are many such cases in ACPICA, and I couldn't see the benefit to introduce such mechanism to such a software whose purposes contain portability. > Unless you can invent a mechanism that can be utilized by all such cases. > Then you should put it into acgcc.h and implement a replaceable in acmsvc.h. > After that, you surely need to do a cleanup in the entire ACPICA code base using this new mechanism. This is only needed in a few cases, so I think general solution would be overkill. That said, it looks like MSVC supports designated initializers. Are people building this with especially old compilers? -Kees > > Thanks > Lv > >> >> >> -Kees >> >> > >> > Thanks >> > Lv >> > >> >> >> >> Signed-off-by: Kees Cook >> >> --- >> >> drivers/acpi/acpica/hwxfsleep.c | 11 ++++++----- >> >> 1 file changed, 6 insertions(+), 5 deletions(-) >> >> >> >> diff --git a/drivers/acpi/acpica/hwxfsleep.c b/drivers/acpi/acpica/hwxfsleep.c >> >> index f76e0eab32b8..25cd5c66e102 100644 >> >> --- a/drivers/acpi/acpica/hwxfsleep.c >> >> +++ b/drivers/acpi/acpica/hwxfsleep.c >> >> @@ -70,11 +70,12 @@ static acpi_status acpi_hw_sleep_dispatch(u8 sleep_state, u32 function_id); >> >> /* Legacy functions are optional, based upon ACPI_REDUCED_HARDWARE */ >> >> >> >> static struct acpi_sleep_functions acpi_sleep_dispatch[] = { >> >> - {ACPI_HW_OPTIONAL_FUNCTION(acpi_hw_legacy_sleep), >> >> - acpi_hw_extended_sleep}, >> >> - {ACPI_HW_OPTIONAL_FUNCTION(acpi_hw_legacy_wake_prep), >> >> - acpi_hw_extended_wake_prep}, >> >> - {ACPI_HW_OPTIONAL_FUNCTION(acpi_hw_legacy_wake), acpi_hw_extended_wake} >> >> + { .legacy_function = ACPI_HW_OPTIONAL_FUNCTION(acpi_hw_legacy_sleep), >> >> + .extended_function = acpi_hw_extended_sleep }, >> >> + { .legacy_function = ACPI_HW_OPTIONAL_FUNCTION(acpi_hw_legacy_wake_prep), >> >> + .extended_function = acpi_hw_extended_wake_prep }, >> >> + { .legacy_function = ACPI_HW_OPTIONAL_FUNCTION(acpi_hw_legacy_wake), >> >> + .extended_function = acpi_hw_extended_wake } >> >> }; >> >> >> >> /* >> >> -- >> >> 2.7.4 >> >> >> >> >> >> -- >> >> Kees Cook >> >> Nexus Security >> >> >> >> -- >> Kees Cook >> Pixel Security -- Kees Cook Pixel Security