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
particular, allow loaders to define the name of the RC script the
interpreter needs to use. Use this new-found control to have the
PXE loader (when compiled with TFTP support and not NFS support)
read from ${bootfile}.4th, where ${bootfile} is the name of the
file fetched by the PXE firmware.
The normal startup process involves reading the following files:
1. /boot/boot.4th
2. /boot/loader.rc or alternatively /boot/boot.conf
When these come from a FreeBSD-defined file system, this is all
good. But when we boot over the network, subdirectories and fixed
file names are often painful to administrators and there's really
no way for them to change the behaviour of the loader.
Obtained from: Juniper Networks, Inc.
percentage of machines has a 16550. Disable it for pc98 since only a
tiny fraction of them have one. These changes save 293 bytes when
building with clang, but preserves the ability to build with serial if
you really want. We now have 92 bytes free (412 with the in-tree gcc).
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]
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.
directly to the linker (LD_FLAGS) from flags passed indirectly, via the
compiler driver (LDFLAGS).
This is because several Makefiles under sys/boot/i386 and sys/boot/pc98
use ${LD} directly to link, and the normal LDFLAGS value should not be
used in these cases.
MFC after: 3 days
being defined in <sys/diskmbr.h>. Instead give the symbols here a
"PC98_" prefix. This way, both <sys/diskmbr.h> and <sys/diskpc98.h>
can be included in the same C source file.
The renaming is trivial. The only gotcha is that DOSBBSECTOR is
also redefined from 0 to 1. This because DOSBBSECTOR was always
used in conjunction with an addition of 1. The PC98_BBSECTOR symbol
is defined as 1 and the expression is simplified.
Note: it is not believed that ports are seriously impacted; or at
all for that matter.
Approved by: nyan@
GDT from the correct segment, otherwise a triple fault would be caused.
In some virtual environments (VMware, VirtualBox, etc) this could lead
to a unhandled error or hang in the guest emulation software.
Thanks to avg and jhb for a few hints in the right direction.
Noticed by: Jeremy Chadwick <jdc@koitsu.org> (and many others)
MFC after: 1 week
i386 comconsole: don't loop forever if hardware doesn't respond
- clear capability flags when hw timeouts
- retire comc_started status variable and directly use c_flags to see
if comconsole is selected for use
default compiler. This has two parts:
- Make sys/boot/pc98/boot2 always build with gcc for now, until we can
figure out a way to shrink it enough when building with clang.
- Since sys/boot/p98/cdboot uses .code16 directives, which are not yet
supported by clang's integrated assembler, use -no-integrated-as,
similar to sys/boot/i386/cdboot.
Reviewed by: nyan
MFC after: 1 week
get rid of testing explicitly for clang (using ${CC:T:Mclang}) in
individual Makefiles.
Instead, use the following extra macros, for use with clang:
- NO_WERROR.clang (disables -Werror)
- NO_WCAST_ALIGN.clang (disables -Wcast-align)
- NO_WFORMAT.clang (disables -Wformat and friends)
- CLANG_NO_IAS (disables integrated assembler)
- CLANG_OPT_SMALL (adds flags for extra small size optimizations)
As a side effect, this enables setting CC/CXX/CPP in src.conf instead of
make.conf! For clang, use the following:
CC=clang
CXX=clang++
CPP=clang-cpp
MFC after: 2 weeks
