1 files changed, 62 insertions, 0 deletions
diff --git a/arch/arm64/kernel/pointer_auth.c b/arch/arm64/kernel/pointer_auth.c
index adb955fd9bdd..f03e5bfe4490 100644
--- a/arch/arm64/kernel/pointer_auth.c
+++ b/arch/arm64/kernel/pointer_auth.c
@@ -46,3 +46,65 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
 
 	return 0;
 }
+
+static u64 arg_to_enxx_mask(unsigned long arg)
+{
+	u64 sctlr_enxx_mask = 0;
+
+	WARN_ON(arg & ~PR_PAC_ENABLED_KEYS_MASK);
+	if (arg & PR_PAC_APIAKEY)
+		sctlr_enxx_mask |= SCTLR_ELx_ENIA;
+	if (arg & PR_PAC_APIBKEY)
+		sctlr_enxx_mask |= SCTLR_ELx_ENIB;
+	if (arg & PR_PAC_APDAKEY)
+		sctlr_enxx_mask |= SCTLR_ELx_ENDA;
+	if (arg & PR_PAC_APDBKEY)
+		sctlr_enxx_mask |= SCTLR_ELx_ENDB;
+	return sctlr_enxx_mask;
+}
+
+int ptrauth_set_enabled_keys(struct task_struct *tsk, unsigned long keys,
+			     unsigned long enabled)
+{
+	u64 sctlr = tsk->thread.sctlr_user;
+
+	if (!system_supports_address_auth())
+		return -EINVAL;
+
+	if (is_compat_thread(task_thread_info(tsk)))
+		return -EINVAL;
+
+	if ((keys & ~PR_PAC_ENABLED_KEYS_MASK) || (enabled & ~keys))
+		return -EINVAL;
+
+	sctlr &= ~arg_to_enxx_mask(keys);
+	sctlr |= arg_to_enxx_mask(enabled);
+	if (tsk == current)
+		set_task_sctlr_el1(sctlr);
+	else
+		tsk->thread.sctlr_user = sctlr;
+
+	return 0;
+}
+
+int ptrauth_get_enabled_keys(struct task_struct *tsk)
+{
+	int retval = 0;
+
+	if (!system_supports_address_auth())
+		return -EINVAL;
+
+	if (is_compat_thread(task_thread_info(tsk)))
+		return -EINVAL;
+
+	if (tsk->thread.sctlr_user & SCTLR_ELx_ENIA)
+		retval |= PR_PAC_APIAKEY;
+	if (tsk->thread.sctlr_user & SCTLR_ELx_ENIB)
+		retval |= PR_PAC_APIBKEY;
+	if (tsk->thread.sctlr_user & SCTLR_ELx_ENDA)
+		retval |= PR_PAC_APDAKEY;
+	if (tsk->thread.sctlr_user & SCTLR_ELx_ENDB)
+		retval |= PR_PAC_APDBKEY;
+
+	return retval;
+}