diff mbox series

[v19,5/7] x86/cet/ibt: Update arch_prctl functions for Indirect Branch Tracking

Message ID 20210203225902.479-6-yu-cheng.yu@intel.com (mailing list archive)
State New, archived
Headers show
Series Control-flow Enforcement: Indirect Branch Tracking | expand

Commit Message

Yu-cheng Yu Feb. 3, 2021, 10:59 p.m. UTC 
From: "H.J. Lu" <hjl.tools@gmail.com>

Update ARCH_X86_CET_STATUS and ARCH_X86_CET_DISABLE for Indirect Branch
Tracking.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
 arch/x86/kernel/cet_prctl.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Kees Cook Feb. 4, 2021, 7:50 p.m. UTC | #1 
On Wed, Feb 03, 2021 at 02:59:00PM -0800, Yu-cheng Yu wrote:
> From: "H.J. Lu" <hjl.tools@gmail.com>
> 
> Update ARCH_X86_CET_STATUS and ARCH_X86_CET_DISABLE for Indirect Branch
> Tracking.
> 
> Signed-off-by: H.J. Lu <hjl.tools@gmail.com>

Reviewed-by: Kees Cook <keescook@chromium.org>
diff mbox series

Patch

diff --git a/arch/x86/kernel/cet_prctl.c b/arch/x86/kernel/cet_prctl.c
index 0030c63a08c0..4df1eac41965 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)
 			cet_disable_shstk();
+		if (arg2 & GNU_PROPERTY_X86_FEATURE_1_IBT)
+			cet_disable_ibt();
 		return 0;
 
 	case ARCH_X86_CET_LOCK: