+comment "Security Hardening Options"
+
+choice
+ bool "Stack Smashing Protection"
+ default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
+ depends on BR2_TOOLCHAIN_HAS_SSP
+ help
+ Enable stack smashing protection support using GCC's
+ -fstack-protector option family.
+
+ 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.
+
+config BR2_SSP_NONE
+ bool "None"
+ help
+ Disable stack-smashing protection.
+
+config BR2_SSP_REGULAR
+ bool "-fstack-protector"
+ help
+ Emit extra code to check for buffer overflows, such as stack
+ smashing attacks. This is done by adding a guard variable to
+ functions with vulnerable objects. This includes functions
+ that call alloca, and functions with buffers larger than 8
+ bytes. The guards are initialized when a function is entered
+ and then checked when the function exits. If a guard check
+ fails, an error message is printed and the program exits.
+
+config BR2_SSP_STRONG
+ bool "-fstack-protector-strong"
+ depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+ help
+ Like -fstack-protector but includes additional functions to be
+ protected - those that have local array definitions, or have
+ references to local frame addresses.
+
+comment "Stack Smashing Protection strong needs a toolchain w/ gcc >= 4.9"
+ depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+
+config BR2_SSP_ALL
+ bool "-fstack-protector-all"
+ help
+ Like -fstack-protector except that all functions are
+ protected. This option might have a significant performance
+ impact on the compiled binaries.
+
+endchoice
+
+comment "Stack Smashing Protection needs a toolchain w/ SSP"
+ depends on !BR2_TOOLCHAIN_HAS_SSP
+
+choice
+ bool "RELRO Protection"
+ depends on BR2_SHARED_LIBS
+ help
+ Enable a link-time protection know as RELRO (RELocation Read
+ Only) which helps to protect from certain type of exploitation
+ techniques altering the content of some ELF sections.
+
+config BR2_RELRO_NONE
+ bool "None"
+ help
+ Disables Relocation link-time protections.
+
+config BR2_RELRO_PARTIAL
+ bool "Partial"
+ help
+ This option makes the dynamic section not writeable after
+ initialization (with almost no performance penalty).
+
+config BR2_RELRO_FULL
+ bool "Full"
+ help
+ This option includes the partial configuration, but also marks
+ the GOT as read-only at the cost of initialization time during
+ program loading, i.e every time an executable is started.
+
+endchoice
+
+comment "RELocation Read Only (RELRO) needs shared libraries"
+ depends on !BR2_SHARED_LIBS
+
+choice
+ bool "Buffer-overflow Detection (FORTIFY_SOURCE)"
+ depends on BR2_TOOLCHAIN_USES_GLIBC
+ depends on !BR2_OPTIMIZE_0
+ help
+ Enable the _FORTIFY_SOURCE macro which introduces additional
+ checks to detect buffer-overflows in the following standard
+ library functions: memcpy, mempcpy, memmove, memset, strcpy,
+ stpcpy, strncpy, strcat, strncat, sprintf, vsprintf, snprintf,
+ vsnprintf, gets.
+
+ NOTE: This feature requires an optimization level of s/1/2/3/g
+
+ Support for this feature has been present since GCC 4.x.
+
+config BR2_FORTIFY_SOURCE_NONE
+ bool "None"
+ help
+ Disables additional checks to detect buffer-overflows.
+
+config BR2_FORTIFY_SOURCE_1
+ bool "Conservative"
+ help
+ This option sets _FORTIFY_SOURCE to 1 and only introduces
+ checks that shouldn't change the behavior of conforming
+ programs. Adds checks at compile-time only.
+
+config BR2_FORTIFY_SOURCE_2
+ bool "Aggressive"
+ help
+ This option sets _FORTIFY_SOURCES to 2 and some more
+ checking is added, but some conforming programs might fail.
+ Also adds checks at run-time (detected buffer overflow
+ terminates the program)
+
+endchoice
+
+comment "Fortify Source needs a glibc toolchain and optimization"
+ depends on (!BR2_TOOLCHAIN_USES_GLIBC || BR2_OPTIMIZE_0)
+endmenu
+