[Buildroot] [PATCH next] tpm2-abrmd: fix build without stack smashing protection (SSP)

[Carlos Santos <casantos@datacom.com.br>]

> From: "DATACOM" <casantos@datacom.com.br>
> To: "Thomas Petazzoni" <thomas.petazzoni@bootlin.com>
> Cc: "buildroot" <buildroot@buildroot.org>
> Sent: Sexta-feira, 23 de novembro de 2018 12:01:24
> Subject: Re: [Buildroot] [PATCH next] tpm2-abrmd: fix build without stack smashing protection (SSP)

>> From: "DATACOM" <casantos@datacom.com.br>
>> To: "Thomas Petazzoni" <thomas.petazzoni@bootlin.com>
>> Cc: "buildroot" <buildroot@buildroot.org>
>> Sent: Quarta-feira, 21 de novembro de 2018 23:46:58
>> Subject: Re: [Buildroot] [PATCH next] tpm2-abrmd: fix build without stack
>> smashing protection (SSP)
> 
>>> From: "Thomas Petazzoni" <thomas.petazzoni@bootlin.com>
>>> To: "DATACOM" <casantos@datacom.com.br>
>>> Cc: "buildroot" <buildroot@buildroot.org>
>>> Sent: Quarta-feira, 21 de novembro de 2018 18:06:52
>>> Subject: Re: [Buildroot] [PATCH next] tpm2-abrmd: fix build without stack
>>> smashing protection (SSP)
>> 
>>> Hello,
>>> 
>>> On Wed, 21 Nov 2018 15:43:37 -0200, Carlos Santos wrote:
>>>> The configuration environment setup that disables SSP if the toolchain
>>>> does not support it must be updated after the bump to version 2.0.3.
>>>> 
>>>> Fixes:
>>>>   http://autobuild.buildroot.net/results/bd9005eeb24678aa530179a80bbc99b2176f8559
>>>>   http://autobuild.buildroot.net/results/feff61dcb481a94f5f030117830984c5e09727ea
>>>> 
>>>> Signed-off-by: Carlos Santos <casantos@datacom.com.br>
>>>> ---
>>>>  package/tpm2-abrmd/tpm2-abrmd.mk | 2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>> 
>>>> diff --git a/package/tpm2-abrmd/tpm2-abrmd.mk b/package/tpm2-abrmd/tpm2-abrmd.mk
>>>> index a4d9cfb384..74cc66ba20 100644
>>>> --- a/package/tpm2-abrmd/tpm2-abrmd.mk
>>>> +++ b/package/tpm2-abrmd/tpm2-abrmd.mk
>>>> @@ -13,7 +13,7 @@ TPM2_ABRMD_DEPENDENCIES = dbus libglib2 tpm2-tss host-pkgconf
>>>>  
>>>>  # configure.ac doesn't contain a link test, so it doesn't detect when
>>>>  # libssp is missing.
>>>> -TPM2_ABRMD_CONF_ENV = ax_cv_check_cflags___fstack_protector_all=$(if
>>>> $(BR2_TOOLCHAIN_HAS_SSP),yes,no)
>>>> +TPM2_ABRMD_CONF_ENV =
>>>> ax_cv_check_cflags___________Werror_______fstack_protector_all=$(if
>>>> $(BR2_TOOLCHAIN_HAS_SSP),yes,no)
>>> 
>>> It's a bit annoying to fix this once in a while, what about the
>>> following change instead:
>>> 
>>> diff --git a/m4/flags.m4 b/m4/flags.m4
>>> index 1b01198..59b6d5b 100644
>>> --- a/m4/flags.m4
>>> +++ b/m4/flags.m4
>>> @@ -5,7 +5,7 @@ dnl   mandatory (configure will fail).
>>> dnl $1: C compiler flag to add to EXTRA_CFLAGS.
>>> dnl $2: Set to "required" to cause configure failure if flag not supported..
>>> AC_DEFUN([AX_ADD_COMPILER_FLAG],[
>>> -    AX_CHECK_COMPILE_FLAG([$1],[
>>> +    AX_CHECK_LINK_FLAG([$1],[
>>>         EXTRA_CFLAGS="$EXTRA_CFLAGS $1"
>>>         AC_SUBST([EXTRA_CFLAGS])],[
>>>         AS_IF([test x$2 != xrequired],[
>>> 
>>> (entirely untested). It could be submitted upstream.
>> 
>> I can forward your suggestion upstream but for the moment I'd keep
>> the CONF_ENV approach.
>> 
>> Patching flags.m4 would require AUTORECONF, which in its turn would
>> require adding host-autoconf-archive as a build dependency. So more
>> dependencies, a larger build to time and exactly the same result.
> 
> Pull request created:
> 
>    https://github.com/tpm2-software/tpm2-abrmd/pull/556

Thomas, could you please accept this patch while we wait for a verdict
from upstream on my PR? It is currently blocked by a build error whose
solution depends on a subsequent PR:

  https://github.com/tpm2-software/tpm2-abrmd/pull/557

-- 
Carlos Santos (Casantos) - DATACOM, P&D