1. 50+% of NO_PIE use is fixed by adding -fPIC to INTERNALLIB and other
build-only utility libraries.
2. Another 40% is fixed by generating _pic.a variants of various libraries.
3. Some of the NO_PIE use is a bit absurd as it is disabling PIE (and ASLR)
where it never would work anyhow, such as csu or loader. This suggests
there may be better ways of adding support to the tree. Many of these
cases can be fixed such that -fPIE will work but there is really no
reason to have it in those cases.
4. Some of the uses are working around hacks done to some Makefiles that are
really building libraries but have been using bsd.prog.mk because the code
is cleaner. Had they been using bsd.lib.mk then NO_PIE would not have
been needed.
We likely do want to enable PIE by default (opt-out) for non-tree consumers
(such as ports). For in-tree though we probably want to only enable PIE
(opt-in) for common attack targets such as remote service daemons and setuid
utilities. This is also a great performance compromise since ASLR is expected
to reduce performance. As such it does not make sense to enable it in all
utilities such as ls(1) that have little benefit to having it enabled.
Reported by: kib
This is currently an opt-in build flag. Once ASLR support is ready and stable
it should changed to opt-out and be enabled by default along with ASLR.
Each application Makefile uses opt-out to ensure that ASLR will be enabled by
default in new directories when the system is compiled with PIE/ASLR. [2]
Mark known build failures as NO_PIE for now.
The only known runtime failure was rtld.
[1] http://www.bsdcan.org/2014/schedule/events/452.en.html
Submitted by: Shawn Webb <lattera@gmail.com>
Discussed between: des@ and Shawn Webb [2]
- Dropped support for standalone builds, this was only partially
supported anyway, and required so much magic in makefiles that
made life dangerous (e.g., by using the custom yacc rules).
- Got rid of .OBJDIR in makefiles -- makes building of individual
files possible again.
- Made the .x.c transformations -j safe.
- Reprogrammed LDADD to fix static build of some utilities that
was broken.
- Fixed LDFLAGS and DPADD in the WITH_OPENLDAP case -- positively
affects the contents of .depend files.
- Removed redundant .h's from SRCS, only kept those that are
generated.
- libkrb5/ INCS were bogusly installed again with libgssapi/.
- Made build-tools real tools with their own makefiles in
separate directories. This allows us to properly track
their dependencies, etc.
- Faster build, 21% less of makefile code!
Approved by: nectar
Reviewed by: markm
Silence on: arch
