Commit Graph

7 Commits

Author SHA1 Message Date
Hauke Mehrtens
19cbac7d26 buildsystem: Make PIE ASLR option tristate
This tristate choose allows to select to build only some applications
with PIE enabled. On MIPS binaries are getting about 30% bigger when PIE
is activated for the, which is a huge increase.

Network exposed applications like dnsmasq should then be build with PIE
enabled, but some applications which are normally not parsing data from
the network do not have it activated. The regular option should give a
good trade off between extra flash and RAM memory usage and security.

This changes the default from building no applications with PIE to build
some specifically marked applications with PIE enabled. This option is
only activated for targets with bigger flash and RAM to not consume
extra memory on the very small targets. On SDK builds the Regular option
should always be selected, because some tiny targets share the
applications with big targets and only the images for the tiny targets
should contain the none PIE applications, but the images for the normal
targets should use PIE. The shared packages should always use PIE when
it should be normally activated.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Petr Štetiar <ynezz@true.cz>
2020-01-13 15:34:36 +01:00
Julien Dusser
4dfa6b7a30 build: fix ASLR for LTO packages
Fix building packages with LTO when CONFIG_PKG_ASLR_PIE is enabled.

Despite comment of PR lto/80838, it seems that GCC needs -fPIC on linker
command line, even if all objects are -fPIC. This may change as PR
lto/80838 is merged into 8.1

compile-tested: ar71xx, ath79

Fix commits:
6dac92a42e
8c11133c9d
07940acc34
e7397eef69
ef16a394d2
ef96d1e34a
47b42137ce
73fc67b614
154c0c4006
804c51e1e6

Signed-off-by: Julien Dusser <julien.dusser@free.fr>
2018-07-30 14:26:16 +02:00
Kevin Darbyshire-Bryant
89b59994eb build: ASLR hardening use $(FPIC)
Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
2018-07-03 14:19:10 +01:00
Julien Dusser
df0bd42fde build: add hardened builds with PIE (ASLR) support
Introduce a configuration option to build a "hardened" OpenWrt with
ASLR PIE support.

Add new option PKG_ASLR_PIE to enable Address Space Layout Randomization (ASLR)
by building Position Independent Executables (PIE). This new option protects
against "return-to-text" attacks.

Busybox need a special care, link is done with ld, not gcc, leading to
unknown flags. Set BUSYBOX_DEFAULT_PIE instead and disable PKG_ASLR_PIE.

If other failing packages were found, PKG_ASLR_PIE:=0 should be added to
their Makefiles.

Original Work by: Yongkui Han <yonhan@cisco.com>
Signed-off-by: Julien Dusser <julien.dusser@free.fr>
2018-01-27 16:46:45 +01:00
Steven Barth
6010a1cdb7 hardening: make override variables more intuitive
Signed-off-by: Steven Barth <steven@midlink.org>

SVN-Revision: 46119
2015-06-24 10:57:14 +00:00
Steven Barth
1877bc9d8f gcc/musl: rework SSP-support
Make musl provide libssp_nonshared.a and make GCC link it unconditionally
if musl is used. This should be a no-op if SSP is disabled and seems to be
the only reliable way of dealing with SSP over all packages due to the mess
that is linkerflags handling in packages.

Signed-off-by: Steven Barth <steven@midlink.org>

SVN-Revision: 46108
2015-06-22 10:31:07 +00:00
Steven Barth
fc5f02410f buildroot: move hardening options into separate file
Signed-off-by: Steven Barth <steven@midlink.org>

SVN-Revision: 46070
2015-06-20 17:37:18 +00:00