diff mbox series

[v12,5/8] x86/cet/ibt: Update arch_prctl functions for Indirect Branch Tracking

Message ID 20200918192312.25978-6-yu-cheng.yu@intel.com
State New
Headers show
Series Control-flow Enforcement: Indirect Branch Tracking | expand

Commit Message

Yu, Yu-cheng Sept. 18, 2020, 7:23 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 | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/x86/kernel/cet_prctl.c b/arch/x86/kernel/cet_prctl.c
index 3e1d049e65c3..78631c5d944e 100644
--- a/arch/x86/kernel/cet_prctl.c
+++ b/arch/x86/kernel/cet_prctl.c
@@ -22,6 +22,9 @@  static int copy_status_to_user(struct cet_status *cet, u64 arg2)
 		buf[2] = (u64)cet->shstk_size;
 	}
 
+	if (cet->ibt_enabled)
+		buf[0] |= GNU_PROPERTY_X86_FEATURE_1_IBT;
+
 	return copy_to_user((u64 __user *)arg2, buf, sizeof(buf));
 }
 
@@ -42,7 +45,8 @@  int prctl_cet(int option, u64 arg2)
 	if (option == ARCH_X86_CET_STATUS)
 		return copy_status_to_user(cet, arg2);
 
-	if (!static_cpu_has(X86_FEATURE_SHSTK))
+	if (!static_cpu_has(X86_FEATURE_SHSTK) &&
+	    !static_cpu_has(X86_FEATURE_IBT))
 		return -EOPNOTSUPP;
 
 	switch (option) {
@@ -56,6 +60,8 @@  int prctl_cet(int option, u64 arg2)
 			return -EINVAL;
 		if (features & GNU_PROPERTY_X86_FEATURE_1_SHSTK)
 			cet_disable_shstk();
+		if (features & GNU_PROPERTY_X86_FEATURE_1_IBT)
+			cet_disable_ibt();
 		return 0;
 
 	case ARCH_X86_CET_LOCK: