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]
license, although the former is pretty safe, it wasn't intended to be
used in the version of MIPS boot2/loader upstreamed to FreeBSD.
MFC after: 3 weeks
Sponsored by: DARPA, AFRL
particular interest in (and support for) SRI International and the
University of Cambridge's BERI FPGA soft-core processor. This includes
micro device drivers for the Altera JTAG UART console, memory-mapped
flash, and the Altera SD Card IP core in both boot2 and loader. boot2
can be written to the on-board Intel StrataFlash on the DE4 board, and
loader can be placed in StrataFlash or the SD Card.
Plenty of XXX comments, but works quite well locally in practice and I
am using it daily. Although I had originally ported the ARM version
of boot2, the current version is x86-derived as that proved more
feature-complete. As we don't currently use partitions on our flash
disks, support for that has been commented out relative to x86, but
would be easy to add back. FDT support has not yet been hooked up,
although some skeleton parts have been put in place for that.
This may well be a useful starting point for ports to other 32-bit and
64-bit MIPS-ISA systems.
This merge is synchronised to CheriBSD github commit
e41d74fd71, but with some additions of
$FreeBSD.
MFC after: 3 weeks
Sponsored by: DARPA, AFRAL
