An ELF file's .note.gnu.property indicates features the file supports. The property is parsed at loading time and passed to arch_setup_elf_ property(). Update it for Indirect Branch Tracking.
Signed-off-by: Yu-cheng Yu <[email protected]> Cc: Kees Cook <[email protected]> --- v24: - Update for splitting shadow stack and ibt. arch/x86/Kconfig | 2 ++ arch/x86/kernel/process_64.c | 8 ++++++++ 2 files changed, 10 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 6bb69fba0dad..7436e3a608e8 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1970,6 +1970,8 @@ config X86_IBT def_bool n depends on X86_SHADOW_STACK depends on $(cc-option,-fcf-protection) + select ARCH_USE_GNU_PROPERTY + select ARCH_BINFMT_ELF_STATE help Indirect Branch Tracking (IBT) provides protection against CALL-/JMP-oriented programming attacks. It is active when diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index d71045b29475..bf8ef10e5b78 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -864,6 +864,14 @@ int arch_setup_elf_property(struct arch_elf_state *state) r = shstk_setup(); } + if (r < 0) + return r; + + if (cpu_feature_enabled(X86_FEATURE_IBT)) { + if (state->gnu_property & GNU_PROPERTY_X86_FEATURE_1_IBT) + r = ibt_setup(); + } + return r; } #endif -- 2.21.0
