linux-kernel - Re: [PATCH 2/2] amdgpu/dc/dml: Support clang option for stack alignment

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CABXOdTeOvFkRp=Z6P47o3ky0HNWkeQ5b_Ff2DVKb8g5tdo3G_Q@mail.gmail.com>
Date:   Wed, 7 Feb 2018 17:34:44 -0800
From:   Guenter Roeck <groeck@...gle.com>
To:     Matthias Kaehlcke <mka@...omium.org>
Cc:     Alex Deucher <alexander.deucher@....com>,
        Christian König <christian.koenig@....com>,
        David Zhou <David1.Zhou@....com>,
        David Airlie <airlied@...ux.ie>,
        Harry Wentland <harry.wentland@....com>,
        Felix Kuehling <Felix.Kuehling@....com>,
        Dmytro Laktyushkin <Dmytro.Laktyushkin@....com>,
        amd-gfx list <amd-gfx@...ts.freedesktop.org>,
        Maling list - DRI developers 
        <dri-devel@...ts.freedesktop.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Guenter Roeck <groeck@...omium.org>,
        Justin TerAvest <teravest@...omium.org>,
        Craig Bergstrom <craigb@...omium.org>
Subject: Re: [PATCH 2/2] amdgpu/dc/dml: Support clang option for stack alignment

On Wed, Feb 7, 2018 at 5:21 PM, Matthias Kaehlcke <mka@...omium.org> wrote:
> DML uses the compiler option -mpreferred-stack-boundary=4 to configure
> a stack alignment of 16 bytes. Clang uses the option -mstack-alignment
> instead, which expects as parameter the alignment in bytes, and not a
> power of two like -mpreferred-stack-boundary.
>
> Probe for both compiler options and use the correct one, similar to
> what is done in arch/x86/Makefile.
>
> Reported-by: Guenter Roeck <groeck@...omium.org>
> Signed-off-by: Matthias Kaehlcke <mka@...omium.org>
> ---
>  drivers/gpu/drm/amd/display/dc/dml/Makefile | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> index b8cadf833e71..740975931d21 100644
> --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
> +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> @@ -24,7 +24,13 @@
>  # It provides the general basic services required by other DAL
>  # subcomponents.
>
> -subdir-ccflags-y += -mhard-float -msse -mpreferred-stack-boundary=4
> +ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
> +       cc_stack_align=-mpreferred-stack-boundary=4
> +else ifneq ($(call cc-option, -mstack-alignment=16),)
> +       cc_stack_align := -mstack-alignment=16
> +endif
> +
Any reason for using both = and := ?

> +subdir-ccflags-y += -mhard-float -msse $(cc_stack_align)
>
>  DML = display_mode_lib.o display_rq_dlg_calc.o \
>           display_rq_dlg_helpers.o dml1_display_rq_dlg_calc.o \
> --
> 2.16.0.rc1.238.g530d649a79-goog
>