[RFC PATCH v9 4/7] x86/cet/ibt: ELF header parsing for Indirect Branch Tracking

[Yu-cheng Yu]

Update arch_setup_elf_property() for Indirect Branch Tracking.

v9:
- Change cpu_feature_enabled() to static_cpu_has().

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
---
 arch/x86/Kconfig             | 2 ++
 arch/x86/kernel/process_64.c | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 563f3c81f323..5c260c047e3c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2003,6 +2003,8 @@ config X86_INTEL_BRANCH_TRACKING_USER
 	def_bool n
 	depends on CPU_SUP_INTEL && X86_64
 	select X86_INTEL_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 99548cde0cc6..9f81b413d975 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -760,6 +760,11 @@ int arch_setup_elf_property(struct arch_elf_state *state)
 			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