RE: [PATCH] ACPICA: use designated initializers

[Zheng, Lv]

Hi,

> From: keescook@xxxxxxxxxx [mailto:keescook@xxxxxxxxxx] On Behalf Of Kees Cook
> Subject: Re: [PATCH] ACPICA: use designated initializers
> 
> On Sun, Dec 18, 2016 at 10:06 PM, Zheng, Lv <lv.zheng@xxxxxxxxx> wrote:
> > Hi,
> >
> >> From: Kees Cook [mailto:keescook@xxxxxxxxxxxx]
> >> 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.

Thanks
Lv

> 
> 
> -Kees
> 
> >
> > Thanks
> > Lv
> >
> >>
> >> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> >> ---
> >>  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