[PATCH v14 4/7] x86/cet/ibt: ELF header parsing for Indirect Branch Tracking

Yu-cheng Yu
2020-10-12T15:45:58Z

Update arch_setup_elf_property() for Indirect Branch Tracking.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
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 15c7f2606c9d..cc9876f85e91 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1972,6 +1972,8 @@ config X86_BRANCH_TRACKING_USER
depends on CPU_SUP_INTEL && X86_64
depends on $(cc-option,-fcf-protection)
select X86_CET
+ 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 8725e67bcd44..1147a1052a07 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -866,6 +866,14 @@ int arch_setup_elf_property(struct arch_elf_state *state)
r = cet_setup_shstk();
}

+ if (r < 0)
+ return r;
+
+ if (static_cpu_has(X86_FEATURE_IBT)) {
+ if (state->gnu_property & GNU_PROPERTY_X86_FEATURE_1_IBT)
+ r = cet_setup_ibt();
+ }
+
return r;
}
#endif
--
2.21.0