Re: [V2 PATCH 1/3] Makefile: fix _FORTIFY_SOURCE redefined build error

From: William Roberts <bill.c.roberts@gmail.com>
To: Jason Zaman <jason@perfinion.com>
Cc: selinux@vger.kernel.org, Stephen Smalley <sds@tycho.nsa.gov>,
	William Roberts <william.c.roberts@intel.com>
Subject: Re: [V2 PATCH 1/3] Makefile: fix _FORTIFY_SOURCE redefined build error
Date: Mon, 31 Dec 2018 08:08:35 -0800	[thread overview]
Message-ID: <CAFftDdqDCVxdHrajJSrxNike0Tr-04WM=FV6Dc8ctUSBSwLjVw@mail.gmail.com> (raw)
In-Reply-To: <20181227142911.GA14910@baraddur.perfinion.com>

On Thu, Dec 27, 2018 at 6:29 AM Jason Zaman <jason@perfinion.com> wrote:
>
> On Wed, Dec 26, 2018 at 06:54:26AM -0800, bill.c.roberts@gmail.com wrote:
> > From: William Roberts <william.c.roberts@intel.com>
> >
> > Certain builds of gcc enable _FORTIFY_SOURCE which results in the error:
> > <command-line>:0:0: warning: "_FORTIFY_SOURCE" redefined
> > <command-line>:0:0: note: this is the location of the previous definition
> >
> > Correct this by undefining it first and redefining it. Also, the previous
> > command line option was using -Wp which is passing the value *AS IS* to the
> > pre-processor rather than to the compiler driver. The C pre-processor has
> > an undocumented interface subject to change per man 1 gcc. Just use the
> > -D option to specify this value.
> >
> > Signed-off-by: William Roberts <william.c.roberts@intel.com>
>
> Acked-by: Jason Zaman <jason@perfinion.com>

merged: https://github.com/SELinuxProject/selinux/pull/120

>
> The whole series looks good to me, go ahead and apply it. I dont think
> the other parts have had _FORTIFY_SOURCE so after next release (probably
> too soon to apply it now?) we might want to add these same warnings to
> everything else not only libselinux.
>
> -- Jason
>
> > ---
> >  libselinux/src/Makefile   | 2 +-
> >  libselinux/utils/Makefile | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/libselinux/src/Makefile b/libselinux/src/Makefile
> > index 977b5c8cfcca..6263d11393e6 100644
> > --- a/libselinux/src/Makefile
> > +++ b/libselinux/src/Makefile
> > @@ -64,7 +64,7 @@ ifeq ($(COMPILER), gcc)
> >  EXTRA_CFLAGS = -fipa-pure-const -Wlogical-op -Wpacked-bitfield-compat -Wsync-nand \
> >       -Wcoverage-mismatch -Wcpp -Wformat-contains-nul -Wnormalized=nfc -Wsuggest-attribute=const \
> >       -Wsuggest-attribute=noreturn -Wsuggest-attribute=pure -Wtrampolines -Wjump-misses-init \
> > -     -Wno-suggest-attribute=pure -Wno-suggest-attribute=const -Wp,-D_FORTIFY_SOURCE
> > +     -Wno-suggest-attribute=pure -Wno-suggest-attribute=const -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE
> >  else
> >  EXTRA_CFLAGS = -Wunused-command-line-argument
> >  endif
> > diff --git a/libselinux/utils/Makefile b/libselinux/utils/Makefile
> > index d06ffd66893b..890ff36f3bbc 100644
> > --- a/libselinux/utils/Makefile
> > +++ b/libselinux/utils/Makefile
> > @@ -30,7 +30,7 @@ CFLAGS ?= -O -Wall -W -Wundef -Wformat-y2k -Wformat-security -Winit-self -Wmissi
> >            -Wformat-extra-args -Wformat-zero-length -Wformat=2 -Wmultichar \
> >            -Woverflow -Wpointer-to-int-cast -Wpragmas \
> >            -Wno-missing-field-initializers -Wno-sign-compare \
> > -          -Wno-format-nonliteral -Wframe-larger-than=$(MAX_STACK_SIZE) -Wp,-D_FORTIFY_SOURCE \
> > +          -Wno-format-nonliteral -Wframe-larger-than=$(MAX_STACK_SIZE) -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE \
> >            -fstack-protector-all --param=ssp-buffer-size=4 -fexceptions \
> >            -fasynchronous-unwind-tables -fdiagnostics-show-option -funit-at-a-time \
> >            -Werror -Wno-aggregate-return -Wno-redundant-decls \
> > --
> > 2.7.4
> >