[RFC PATCH v9 5/7] x86/cet/ibt: Add arch_prctl functions for Indirect Branch Tracking

[Yu-cheng Yu]

From: "H.J. Lu" <hjl.tools@xxxxxxxxx>

Update ARCH_X86_CET_STATUS and ARCH_X86_CET_DISABLE for Indirect Branch
Tracking.

Signed-off-by: H.J. Lu <hjl.tools@xxxxxxxxx>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
---
 arch/x86/kernel/cet_prctl.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/kernel/cet_prctl.c b/arch/x86/kernel/cet_prctl.c
index 6cf8f87e3d98..2a3170786a3b 100644
--- a/arch/x86/kernel/cet_prctl.c
+++ b/arch/x86/kernel/cet_prctl.c
@@ -20,6 +20,8 @@ static int handle_get_status(unsigned long arg2)
 
 	if (cet->shstk_enabled)
 		features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
+	if (cet->ibt_enabled)
+		features |= GNU_PROPERTY_X86_FEATURE_1_IBT;
 
 	buf[0] = (unsigned long)features;
 	buf[1] = cet->shstk_base;
@@ -68,6 +70,8 @@ int prctl_cet(int option, unsigned long arg2)
 			return -EPERM;
 		if (arg2 & GNU_PROPERTY_X86_FEATURE_1_SHSTK)
 			cet_disable_free_shstk(current);
+		if (arg2 & GNU_PROPERTY_X86_FEATURE_1_IBT)
+			cet_disable_ibt();
 
 		return 0;
 
-- 
2.21.0