Re: [platforms: PATCH 05/10] Marvell/Library: MppLib: Disable the stack protector

[Leif Lindholm <leif.lindholm@linaro.org>]

On Thu, Oct 26, 2017 at 02:29:02PM +0100, Ard Biesheuvel wrote:
> On 26 October 2017 at 14:26, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> > On Thu, Oct 26, 2017 at 03:19:32AM +0200, Marcin Wojtas wrote:
> >> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >>
> >> MppLib may be used very early (in SEC), at which point stack protection
> >> measures are more likely to cause harm than help, given that not even
> >> the UART has been configured to the point where we can complain usefully.
> >> So just disable it.
> >
> > It may. But it is also used by PlatInitDxe.
> > Can we use different build options for SEC and later phases?
> 
> No, libraries are only built a single time during the build, and
> linked into every module that depends on them. This is the same issue
> we had with -mstrict-align.

Sure, but we could have duplicated the .inf and have a SEC version and
use that mapping for SEC...

Clearly that's tedious. I guess it comes down to how useful we think
the stack checking is in general. If the answer is "not very, to be
honest":
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

/
    Leif

> >> Contributed-under: TianoCore Contribution Agreement 1.1
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >> Signed-off-by: Marcin Wojtas <mw@semihalf.com>
> >> ---
> >>  Platform/Marvell/Library/MppLib/MppLib.inf | 3 +++
> >>  1 file changed, 3 insertions(+)
> >>
> >> diff --git a/Platform/Marvell/Library/MppLib/MppLib.inf b/Platform/Marvell/Library/MppLib/MppLib.inf
> >> index 2de9cd0..1268542 100644
> >> --- a/Platform/Marvell/Library/MppLib/MppLib.inf
> >> +++ b/Platform/Marvell/Library/MppLib/MppLib.inf
> >> @@ -106,3 +106,6 @@
> >>    gMarvellTokenSpaceGuid.PcdChip3MppSel7
> >>
> >>    gMarvellTokenSpaceGuid.PcdPciESdhci
> >> +
> >> +[BuildOptions]
> >> +  *_*_*_CC_FLAGS = -fno-stack-protector
> >> --
> >> 2.7.4
> >>