[Buildroot] [PATCHv2 10/14] toolchain: refactor Stack Smashing Protection support
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Mon Sep 2 16:06:36 UTC 2013
This commit refactors how Stack Smashing Protection support is handled
in Buildroot:
*) It turns the BR2_TOOLCHAIN_BUILDROOT_USE_SSP option into an option
that only enables the SSP support in uClibc, when using the internal
toolchain backend.
*) It adds an hidden BR2_TOOLCHAIN_HAS_SSP option that gets enabled
when the toolchain has SSP support. Here we have the usual dance:
glibc/eglibc in internal/external backend always select this
option, in the case of uClibc/internal, it gets selected when
BR2_TOOLCHAIN_BUILDROOT_USE_SSP is enabled, in the case of
uClibc/external, there is a new configuration option that the user
must select (or not) depending on whether the toolchain has SSP
support.
*) It adds a new options BR2_ENABLE_SSP in the "Build options" menu,
to enable the usage of SSP support, by adding
-fstack-protector-all to the CFLAGS.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
Config.in | 17 +++++++++++++++++
package/Makefile.in | 2 +-
package/psmisc/psmisc.mk | 4 ++--
package/uclibc/Config.in | 10 ++++++++++
toolchain/Config.in | 1 +
toolchain/helpers.mk | 3 ++-
toolchain/toolchain-buildroot/Config.in.2 | 9 ---------
toolchain/toolchain-common.in | 3 +++
toolchain/toolchain-external/Config.in | 9 +++++++++
9 files changed, 45 insertions(+), 13 deletions(-)
diff --git a/Config.in b/Config.in
index cb246a4..8046d6e 100644
--- a/Config.in
+++ b/Config.in
@@ -398,6 +398,23 @@ config BR2_OPTIMIZE_S
endchoice
+config BR2_ENABLE_SSP
+ bool "build code with Stack Smashing Protection"
+ depends on BR2_TOOLCHAIN_HAS_SSP
+ help
+ Enable stack smashing protection support using GCCs
+ -fstack-protector-all option.
+
+ See http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
+ for details.
+
+ Note that this requires the toolchain to have SSP
+ support. This is always the case for glibc and eglibc
+ toolchain, but is optional in uClibc toolchains.
+
+comment "enabling Stack Smashing Protection requires support in the toolchain"
+ depends on !BR2_TOOLCHAIN_HAS_SSP
+
config BR2_PREFER_STATIC_LIB
bool "prefer static libraries"
help
diff --git a/package/Makefile.in b/package/Makefile.in
index 0b1c33a..3eaa2b2 100644
--- a/package/Makefile.in
+++ b/package/Makefile.in
@@ -129,7 +129,7 @@ TARGET_CFLAGS += -msep-data
TARGET_CXXFLAGS += -msep-data
endif
-ifeq ($(BR2_TOOLCHAIN_BUILDROOT_USE_SSP),y)
+ifeq ($(BR2_ENABLE_SSP),y)
TARGET_CFLAGS += -fstack-protector-all
TARGET_CXXFLAGS += -fstack-protector-all
endif
diff --git a/package/psmisc/psmisc.mk b/package/psmisc/psmisc.mk
index 1340ee6..c18ba94 100644
--- a/package/psmisc/psmisc.mk
+++ b/package/psmisc/psmisc.mk
@@ -10,8 +10,8 @@ PSMISC_LICENSE = GPLv2
PSMISC_LICENSE_FILES = COPYING
PSMISC_DEPENDENCIES = ncurses $(if $(BR2_NEEDS_GETTEXT_IF_LOCALE),gettext)
-ifneq ($(BR2_TOOLCHAIN_BUILDROOT_USE_SSP),y)
-# Don't force -fstack-protector
+ifeq ($(BR2_TOOLCHAIN_HAS_SSP),)
+# Don't force -fstack-protector when SSP is not available in toolchain
PSMISC_CONF_OPT = --disable-harden-flags
endif
diff --git a/package/uclibc/Config.in b/package/uclibc/Config.in
index 037ca01..eeb3b83 100644
--- a/package/uclibc/Config.in
+++ b/package/uclibc/Config.in
@@ -130,6 +130,16 @@ config BR2_PTHREAD_DEBUG
help
Build the thread library with debugging enabled.
+config BR2_TOOLCHAIN_BUILDROOT_USE_SSP
+ bool "Enable stack protection support"
+ select BR2_TOOLCHAIN_HAS_SSP
+ help
+ Enable stack smashing protection support using GCCs
+ -fstack-protector-all option in uClibc.
+
+ See http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
+ for details.
+
config BR2_UCLIBC_INSTALL_UTILS
bool "Compile and install uClibc utilities"
depends on !BR2_bfin
diff --git a/toolchain/Config.in b/toolchain/Config.in
index 64cdf81..da9cd68 100644
--- a/toolchain/Config.in
+++ b/toolchain/Config.in
@@ -18,6 +18,7 @@ config BR2_TOOLCHAIN_USES_GLIBC
select BR2_TOOLCHAIN_HAS_THREADS
select BR2_TOOLCHAIN_HAS_THREADS_DEBUG
select BR2_TOOLCHAIN_HAS_SHADOW_PASSWORDS
+ select BR2_TOOLCHAIN_HAS_SSP
select BR2_TOOLCHAIN_LIBC_NEEDS_THREE_STAGE_BUILD
config BR2_TOOLCHAIN_USES_UCLIBC
diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
index 44b6018..0e270ee 100644
--- a/toolchain/helpers.mk
+++ b/toolchain/helpers.mk
@@ -258,7 +258,8 @@ check_uclibc = \
$(call check_uclibc_feature,__UCLIBC_HAS_LOCALE__,BR2_ENABLE_LOCALE,$${UCLIBC_CONFIG_FILE},Locale support) ;\
$(call check_uclibc_feature,__UCLIBC_HAS_WCHAR__,BR2_USE_WCHAR,$${UCLIBC_CONFIG_FILE},Wide char support) ;\
$(call check_uclibc_feature,__UCLIBC_HAS_THREADS__,BR2_TOOLCHAIN_HAS_THREADS,$${UCLIBC_CONFIG_FILE},Thread support) ;\
- $(call check_uclibc_feature,__PTHREADS_DEBUG_SUPPORT__,BR2_TOOLCHAIN_HAS_THREADS_DEBUG,$${UCLIBC_CONFIG_FILE},Thread debugging support)
+ $(call check_uclibc_feature,__PTHREADS_DEBUG_SUPPORT__,BR2_TOOLCHAIN_HAS_THREADS_DEBUG,$${UCLIBC_CONFIG_FILE},Thread debugging support) ;\
+ $(call check_uclibc_feature,__UCLIBC_HAS_SSP__,BR2_TOOLCHAIN_HAS_SSP,$${UCLIBC_CONFIG_FILE},Stack Smashing Protection support)
#
# Check that the Buildroot configuration of the ABI matches the
diff --git a/toolchain/toolchain-buildroot/Config.in.2 b/toolchain/toolchain-buildroot/Config.in.2
index 1371c31..df26079 100644
--- a/toolchain/toolchain-buildroot/Config.in.2
+++ b/toolchain/toolchain-buildroot/Config.in.2
@@ -4,15 +4,6 @@ if BR2_TOOLCHAIN_BUILDROOT
comment "Toolchain Options"
-config BR2_TOOLCHAIN_BUILDROOT_USE_SSP
- bool "Enable stack protection support"
- help
- Enable stack smashing protection support using GCCs
- -fstack-protector-all option.
-
- See http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
- for details.
-
source "package/elf2flt/Config.in.host"
endif
diff --git a/toolchain/toolchain-common.in b/toolchain/toolchain-common.in
index dc3bd2a..1085fb3 100644
--- a/toolchain/toolchain-common.in
+++ b/toolchain/toolchain-common.in
@@ -32,6 +32,9 @@ config BR2_TOOLCHAIN_HAS_THREADS_DEBUG
config BR2_TOOLCHAIN_HAS_SHADOW_PASSWORDS
bool
+config BR2_TOOLCHAIN_HAS_SSP
+ bool
+
config BR2_ENABLE_LOCALE_PURGE
bool "Purge unwanted locales"
help
diff --git a/toolchain/toolchain-external/Config.in b/toolchain/toolchain-external/Config.in
index ad1f203..11edc98 100644
--- a/toolchain/toolchain-external/Config.in
+++ b/toolchain/toolchain-external/Config.in
@@ -921,6 +921,15 @@ config BR2_TOOLCHAIN_EXTERNAL_HAS_THREADS_DEBUG
debugging support. If you don't know, leave the default
value, Buildroot will tell you if it's correct or not.
+config BR2_TOOLCHAIN_EXTERNAL_HAS_SSP
+ bool "Toolchain has SSP support?"
+ select BR2_TOOLCHAIN_HAS_SSP
+ help
+ Selection this option if your external toolchain has Stack
+ Smashing Protection support enabled. If you don't know,
+ leave the default value, Buildroot will tell you if it's
+ correct or not.
+
endif # BR2_TOOLCHAIN_EXTERNAL_CUSTOM_UCLIBC
config BR2_TOOLCHAIN_EXTERNAL_INET_RPC
--
1.8.1.2
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