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From:   Yu-cheng Yu <yu-cheng.yu@intel.com>
To:     x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
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Cc:     Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v11 4/9] x86/cet/ibt: ELF header parsing for Indirect Branch Tracking
Date:   Mon, 24 Aug 2020 17:26:39 -0700
Message-Id: <20200825002645.3658-5-yu-cheng.yu@intel.com>
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Update arch_setup_elf_property() for Indirect Branch Tracking.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
v9:
- Change cpu_feature_enabled() to static_cpu_has().

 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 b047e0a8d1c2..5bd6d6a10047 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1969,6 +1969,8 @@ config X86_INTEL_BRANCH_TRACKING_USER
 	depends on CPU_SUP_INTEL && X86_64
 	depends on $(cc-option,-fcf-protection)
 	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 fd4644865a3b..c084e1a37d11 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