Hello Michael, on my local workstation (featuring an Intel i5-6500), the kernel takes ~ 48 minutes to compile with randstruct enabled, which is around the same time I have experienced before. Thanks, and best regards, Peter Müller > Do we finally know how much the impact is at compile time? > > -Michael > >> On 1 Aug 2022, at 18:18, Peter Müller wrote: >> >> To quote from the kernel documentation: >> >>> If you say Y here, the layouts of structures that are entirely >>> function pointers (and have not been manually annotated with >>> __no_randomize_layout), or structures that have been explicitly >>> marked with __randomize_layout, will be randomized at compile-time. >>> This can introduce the requirement of an additional information >>> exposure vulnerability for exploits targeting these structure >>> types. >>> >>> Enabling this feature will introduce some performance impact, >>> slightly increase memory usage, and prevent the use of forensic >>> tools like Volatility against the system (unless the kernel >>> source tree isn't cleaned after kernel installation). >>> >>> The seed used for compilation is located at >>> scripts/gcc-plgins/randomize_layout_seed.h. It remains after >>> a make clean to allow for external modules to be compiled with >>> the existing seed and will be removed by a make mrproper or >>> make distclean. >>> >>> Note that the implementation requires gcc 4.7 or newer. >> >> Signed-off-by: Peter Müller >> --- >> config/kernel/kernel.config.x86_64-ipfire | 3 ++- >> config/rootfiles/common/aarch64/linux | 5 +++++ >> config/rootfiles/common/armv6l/linux | 5 +++++ >> config/rootfiles/common/x86_64/linux | 5 +++++ >> 4 files changed, 17 insertions(+), 1 deletion(-) >> >> diff --git a/config/kernel/kernel.config.x86_64-ipfire b/config/kernel/kernel.config.x86_64-ipfire >> index 40975b5fc..c8e7ada01 100644 >> --- a/config/kernel/kernel.config.x86_64-ipfire >> +++ b/config/kernel/kernel.config.x86_64-ipfire >> @@ -793,7 +793,8 @@ CONFIG_HAVE_GCC_PLUGINS=y >> CONFIG_GCC_PLUGINS=y >> # CONFIG_GCC_PLUGIN_CYC_COMPLEXITY is not set >> CONFIG_GCC_PLUGIN_LATENT_ENTROPY=y >> -# CONFIG_GCC_PLUGIN_RANDSTRUCT is not set >> +CONFIG_GCC_PLUGIN_RANDSTRUCT=y >> +CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE=y >> # end of General architecture-dependent options >> >> CONFIG_RT_MUTEXES=y >> diff --git a/config/rootfiles/common/aarch64/linux b/config/rootfiles/common/aarch64/linux >> index dbd6e8f2f..b3a642e56 100644 >> --- a/config/rootfiles/common/aarch64/linux >> +++ b/config/rootfiles/common/aarch64/linux >> @@ -7646,6 +7646,8 @@ etc/modprobe.d/ipv6.conf >> #lib/modules/KVER-ipfire/build/include/config/GARP >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGINS >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_LATENT_ENTROPY >> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT >> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT_PERFORMANCE >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK_BYREF_ALL >> #lib/modules/KVER-ipfire/build/include/config/GCC_VERSION >> @@ -11684,6 +11686,7 @@ etc/modprobe.d/ipv6.conf >> #lib/modules/KVER-ipfire/build/include/generated/autoconf.h >> #lib/modules/KVER-ipfire/build/include/generated/bounds.h >> #lib/modules/KVER-ipfire/build/include/generated/compile.h >> +#lib/modules/KVER-ipfire/build/include/generated/randomize_layout_hash.h >> #lib/modules/KVER-ipfire/build/include/generated/timeconst.h >> #lib/modules/KVER-ipfire/build/include/generated/uapi >> #lib/modules/KVER-ipfire/build/include/generated/uapi/linux >> @@ -17129,6 +17132,8 @@ etc/modprobe.d/ipv6.conf >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.c >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.so >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.c >> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.so >> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_seed.h >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/sancov_plugin.c >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/stackleak_plugin.c >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/structleak_plugin.c >> diff --git a/config/rootfiles/common/armv6l/linux b/config/rootfiles/common/armv6l/linux >> index 79e4facfe..c3411fe8d 100644 >> --- a/config/rootfiles/common/armv6l/linux >> +++ b/config/rootfiles/common/armv6l/linux >> @@ -8071,6 +8071,8 @@ etc/modprobe.d/ipv6.conf >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGINS >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_ARM_SSP_PER_TASK >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_LATENT_ENTROPY >> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT >> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT_PERFORMANCE >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK_BYREF_ALL >> #lib/modules/KVER-ipfire/build/include/config/GCC_VERSION >> @@ -12134,6 +12136,7 @@ etc/modprobe.d/ipv6.conf >> #lib/modules/KVER-ipfire/build/include/generated/autoconf.h >> #lib/modules/KVER-ipfire/build/include/generated/bounds.h >> #lib/modules/KVER-ipfire/build/include/generated/compile.h >> +#lib/modules/KVER-ipfire/build/include/generated/randomize_layout_hash.h >> #lib/modules/KVER-ipfire/build/include/generated/timeconst.h >> #lib/modules/KVER-ipfire/build/include/generated/uapi >> #lib/modules/KVER-ipfire/build/include/generated/uapi/linux >> @@ -17579,6 +17582,8 @@ etc/modprobe.d/ipv6.conf >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.c >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.so >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.c >> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.so >> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_seed.h >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/sancov_plugin.c >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/stackleak_plugin.c >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/structleak_plugin.c >> diff --git a/config/rootfiles/common/x86_64/linux b/config/rootfiles/common/x86_64/linux >> index b25f85a3a..1b78fe8c5 100644 >> --- a/config/rootfiles/common/x86_64/linux >> +++ b/config/rootfiles/common/x86_64/linux >> @@ -7624,6 +7624,8 @@ etc/modprobe.d/ipv6.conf >> #lib/modules/KVER-ipfire/build/include/config/GARP >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGINS >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_LATENT_ENTROPY >> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT >> +#lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_RANDSTRUCT_PERFORMANCE >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK >> #lib/modules/KVER-ipfire/build/include/config/GCC_PLUGIN_STRUCTLEAK_BYREF_ALL >> #lib/modules/KVER-ipfire/build/include/config/GCC_VERSION >> @@ -12128,6 +12130,7 @@ etc/modprobe.d/ipv6.conf >> #lib/modules/KVER-ipfire/build/include/generated/autoconf.h >> #lib/modules/KVER-ipfire/build/include/generated/bounds.h >> #lib/modules/KVER-ipfire/build/include/generated/compile.h >> +#lib/modules/KVER-ipfire/build/include/generated/randomize_layout_hash.h >> #lib/modules/KVER-ipfire/build/include/generated/timeconst.h >> #lib/modules/KVER-ipfire/build/include/generated/uapi >> #lib/modules/KVER-ipfire/build/include/generated/uapi/linux >> @@ -17567,6 +17570,8 @@ etc/modprobe.d/ipv6.conf >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.c >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/latent_entropy_plugin.so >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.c >> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_plugin.so >> +#lib/modules/KVER-ipfire/build/scripts/gcc-plugins/randomize_layout_seed.h >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/sancov_plugin.c >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/stackleak_plugin.c >> #lib/modules/KVER-ipfire/build/scripts/gcc-plugins/structleak_plugin.c >> -- >> 2.35.3 >