1 files changed, 70 insertions, 4 deletions

diff --git a/arch/arm64/kernel/pointer_auth.c b/arch/arm64/kernel/pointer_auth.c
index c507b584259d..2708b620b4ae 100644
--- a/arch/arm64/kernel/pointer_auth.c
+++ b/arch/arm64/kernel/pointer_auth.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 
+#include <linux/compat.h>
 #include <linux/errno.h>
 #include <linux/prctl.h>
 #include <linux/random.h>
@@ -9,7 +10,7 @@
 
 int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
 {
-	struct ptrauth_keys *keys = &tsk->thread.keys_user;
+	struct ptrauth_keys_user *keys = &tsk->thread.keys_user;
 	unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY |
 				      PR_PAC_APDAKEY | PR_PAC_APDBKEY;
 	unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY;
@@ -17,9 +18,11 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
 	if (!system_supports_address_auth() && !system_supports_generic_auth())
 		return -EINVAL;
 
+	if (is_compat_thread(task_thread_info(tsk)))
+		return -EINVAL;
+
 	if (!arg) {
-		ptrauth_keys_init(keys);
-		ptrauth_keys_switch(keys);
+		ptrauth_keys_init_user(keys);
 		return 0;
 	}
 
@@ -40,8 +43,71 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
 		get_random_bytes(&keys->apdb, sizeof(keys->apdb));
 	if (arg & PR_PAC_APGAKEY)
 		get_random_bytes(&keys->apga, sizeof(keys->apga));
+	ptrauth_keys_install_user(keys);
+
+	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;
 
-	ptrauth_keys_switch(keys);
+	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;
+
+	preempt_disable();
+	sctlr = tsk->thread.sctlr_user;
+	sctlr &= ~arg_to_enxx_mask(keys);
+	sctlr |= arg_to_enxx_mask(enabled);
+	tsk->thread.sctlr_user = sctlr;
+	if (tsk == current)
+		update_sctlr_el1(sctlr);
+	preempt_enable();
 
 	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;
+}