Re: [PATCH 5/5] security_flags: ensure changes to SHARED_OBJECTS cause recompile

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Fri, 2016-08-19 at 16:34 +0100, Joshua Lock wrote:
> Add the SHARED_OBJECTS variable to SECURITY_LDFLAGS vardeps so that
> changing SHARED_OBJECTS causes do_compile to re-run.
> 
> Signed-off-by: Joshua Lock <joshua.g.lock@intel.com>
> ---
>  meta/conf/distro/include/security_flags.inc | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/meta/conf/distro/include/security_flags.inc
> b/meta/conf/distro/include/security_flags.inc
> index 295c733..901c841 100644
> --- a/meta/conf/distro/include/security_flags.inc
> +++ b/meta/conf/distro/include/security_flags.inc
> @@ -24,6 +24,7 @@ SECURITY_CFLAGS ?= "-fstack-protector-strong -
> -param ssp-buffer-size=4 -pie -fpi
>  SECURITY_NO_PIE_CFLAGS ?= "-fstack-protector-strong --param ssp
> -buffer-size=4 ${lcl_maybe_fortify} ${SECURITY_STRINGFORMAT}"
>  
>  SECURITY_LDFLAGS ?= "-Wl,-z,relro,-z,now${pie_ld}"
> +SECURITY_LDFLAGS[vardeps] += "SHARED_OBJECTS"

Surely you want:

pid_ld[vardeps] += "SHARED_OBJECTS"

?

Also, you mention SHARED_OBJECTS defaults to "0", where is that? I am a
little worried the variable name is also a bit generic? Setting this in
the following way:

SECURITY_SHARED_OBJECTS = "-fpie"
SECURITY_SHARED_OBJECTS_pn-XXX = ""

may be more in keeping with the way the rest of the file is written and
avoids games with base_conditional and vardeps?

I am also worried about trying to maintain a large list like this, the
idea was to reduce the number of exceptions, not build lists which will
ever increase :(. I can't see this scaling.

Cheers,

Richard