This patch implements the --enable-host-pie configure option which
makes the compiler executables PIE. This can be used to enhance
protection against ROP attacks, and can be viewed as part of a wider
trend to harden binaries.
It is similar to the option --enable-host-shared, except that --e-h-s
won't add -shared to the linker flags whereas --e-h-p will add -pie.
It is different from --enable-default-pie because that option just
adds an implicit -fPIE/-pie when the compiler is invoked, but the
compiler itself isn't PIE.
Since r12-5768-gfe7c3ecf, PCH works well with PIE, so there are no PCH
regressions.
When building the compiler, the build process may use various in-tree
libraries; these need to be built with -fPIE so that it's possible to
use them when building a PIE. For instance, when --with-included-gettext
is in effect, intl object files must be compiled with -fPIE. Similarly,
when building in-tree gmp, isl, mpfr and mpc, they must be compiled with
-fPIE.
I plan to add an option to link with -Wl,-z,now.
ChangeLog:
* Makefile.def: Pass $(PICFLAG) to AM_CFLAGS for gmp, mpfr, mpc, and
isl.
* Makefile.in: Regenerate.
* Makefile.tpl: Set PICFLAG.
* configure.ac (--enable-host-pie): New check. Set PICFLAG after this
check.
* configure: Regenerate.
c++tools/ChangeLog:
* Makefile.in: Rename PIEFLAG to PICFLAG. Set LD_PICFLAG. Use it.
Use pic/libiberty.a if PICFLAG is set.
* configure.ac (--enable-default-pie): Set PICFLAG instead of PIEFLAG.
(--enable-host-pie): New check.
* configure: Regenerate.
fixincludes/ChangeLog:
* Makefile.in: Set and use PICFLAG and LD_PICFLAG. Use the "pic"
build of libiberty if PICFLAG is set.
* configure.ac:
* configure: Regenerate.
gcc/ChangeLog:
* Makefile.in: Set LD_PICFLAG. Use it. Set enable_host_pie.
Remove NO_PIE_CFLAGS and NO_PIE_FLAG. Pass LD_PICFLAG to
ALL_LINKERFLAGS. Use the "pic" build of libiberty if --enable-host-pie.
* configure.ac (--enable-host-shared): Don't set PICFLAG here.
(--enable-host-pie): New check. Set PICFLAG and LD_PICFLAG after this
check.
* configure: Regenerate.
* doc/install.texi: Document --enable-host-pie.
gcc/d/ChangeLog:
* Make-lang.in: Remove NO_PIE_CFLAGS.
intl/ChangeLog:
* Makefile.in: Use @PICFLAG@ in COMPILE as well.
* configure.ac (--enable-host-shared): Don't set PICFLAG here.
(--enable-host-pie): New check. Set PICFLAG after this check.
* configure: Regenerate.
libcody/ChangeLog:
* Makefile.in: Pass LD_PICFLAG to LDFLAGS.
* configure.ac (--enable-host-shared): Don't set PICFLAG here.
(--enable-host-pie): New check. Set PICFLAG and LD_PICFLAG after this
check.
* configure: Regenerate.
libcpp/ChangeLog:
* configure.ac (--enable-host-shared): Don't set PICFLAG here.
(--enable-host-pie): New check. Set PICFLAG after this check.
* configure: Regenerate.
libdecnumber/ChangeLog:
* configure.ac (--enable-host-shared): Don't set PICFLAG here.
(--enable-host-pie): New check. Set PICFLAG after this check.
* configure: Regenerate.
libiberty/ChangeLog:
* configure.ac: Also set shared when enable_host_pie.
* configure: Regenerate.
zlib/ChangeLog:
* configure.ac (--enable-host-shared): Don't set PICFLAG here.
(--enable-host-pie): New check. Set PICFLAG after this check.
* configure: Regenerate.
While this doesn't fix 98324, it was an omission. Cribbed code from
libcpp to build libcody as PIC.
libcody/
* configure.ac: Add --enable-host-shared.
* Makefile.in: Add FLAGPIC.
* configure: Regenerated.
> The -enable-checking configure code in libcody didn't play well with
> us. This just uses libcpp's configurey for that piece.
This doesn't set is_release anywhere, which means when --enable-checking*
or --disable-checking isn't specified, it always treats it as
--enable-checking=yes, while the normal gcc behavior is treat only trunk
as --enable-checking=yes and treat release branches as
--enable-checking=release by default.
On the other side, nothing uses those ac_assert_checking and
ac_valgrind_checking variables, so it is a waste to compute those.
2020-12-16 Jakub Jelinek <jakub@redhat.com>
* configure.ac: Compute is_release.
(NMS_ENABLE_CHECKING): Simplify but not computing ac_assert_checking
and ac_valgrind_checking the code doesn't use.
* configure: Regenerated.
The -enable-checking configure code in libcody didn't play well with
us. This just uses libcpp's configurey for that piece.
libcody/
* configure.ac: Use libcpp's enable-checking code.
* configure: Rebuilt.
