# \[PATCH v24 5/9\] x86/cet/ibt: Update arch\_prctl functions for Indirect Branch Tracking

- From: Yu-cheng Yu \<hidden\>
- Date: 2021-04-01 22:15:00 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2021/04/6324711
- Thread: https://ratatoskr.run/linux-doc/2021/04/6324705/t.md

```text
From: "H.J. Lu" <redacted>

Update ARCH_X86_CET_STATUS and ARCH_X86_CET_DISABLE for Indirect Branch
Tracking.

Signed-off-by: H.J. Lu <redacted>
Signed-off-by: Yu-cheng Yu <redacted>
Reviewed-by: Kees Cook <redacted>
---
v24:
- Update for function name changes introduced from splitting shadow stack and ibt.

 arch/x86/kernel/cet_prctl.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/kernel/cet_prctl.c b/arch/x86/kernel/cet_prctl.c
index 5f0054177d2a..ae31741d829a 100644
--- a/arch/x86/kernel/cet_prctl.c
+++ b/arch/x86/kernel/cet_prctl.c
@@ -22,6 +22,9 @@ static int cet_copy_status_to_user(struct cet_status *cet, u64 __user *ubuf)
 		buf[2] = cet->shstk_size;
 	}
 
+	if (cet->ibt_enabled)
+		buf[0] |= GNU_PROPERTY_X86_FEATURE_1_IBT;
+
 	return copy_to_user(ubuf, buf, sizeof(buf));
 }
 
@@ -46,6 +49,8 @@ int prctl_cet(int option, u64 arg2)
 			return -EINVAL;
 		if (arg2 & GNU_PROPERTY_X86_FEATURE_1_SHSTK)
 			shstk_disable();
+		if (arg2 & GNU_PROPERTY_X86_FEATURE_1_IBT)
+			ibt_disable();
 		return 0;
 
 	case ARCH_X86_CET_LOCK:
-- 
2.21.0

```