arm64: rename ptrauth key structures to be user-specific

We currently enable ptrauth for userspace, but do not use it within the
kernel. We're going to enable it for the kernel, and will need to manage
a separate set of ptrauth keys for the kernel.

We currently keep all 5 keys in struct ptrauth_keys. However, as the
kernel will only need to use 1 key, it is a bit wasteful to allocate a
whole ptrauth_keys struct for every thread.

Therefore, a subsequent patch will define a separate struct, with only 1
key, for the kernel. In preparation for that, rename the existing struct
(and associated macros and functions) to reflect that they are specific
to userspace.

Acked-by: Catalin Marinas <[email protected]>
Reviewed-by: Vincenzo Frascino <[email protected]>
Signed-off-by: Kristina Martsenko <[email protected]>
[Amit: Re-positioned the patch to reduce the diff]
Signed-off-by: Amit Daniel Kachhap <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>

Author: kristina-martsenko

arch/arm64/include/asm/pointer_auth.h

@@ -22,15 +22,15 @@ struct ptrauth_key {
  * We give each process its own keys, which are shared by all threads. The keys
  * are inherited upon fork(), and reinitialised upon exec*().
  */
-struct ptrauth_keys {
+struct ptrauth_keys_user {
 	struct ptrauth_key apia;
 	struct ptrauth_key apib;
 	struct ptrauth_key apda;
 	struct ptrauth_key apdb;
 	struct ptrauth_key apga;
 };
 
-static inline void ptrauth_keys_init(struct ptrauth_keys *keys)
+static inline void ptrauth_keys_init_user(struct ptrauth_keys_user *keys)
 {
 	if (system_supports_address_auth()) {
 		get_random_bytes(&keys->apia, sizeof(keys->apia));
@@ -50,7 +50,7 @@ do {								\
 	write_sysreg_s(__pki_v.hi, SYS_ ## k ## KEYHI_EL1);	\
 } while (0)
 
-static inline void ptrauth_keys_switch(struct ptrauth_keys *keys)
+static inline void ptrauth_keys_switch_user(struct ptrauth_keys_user *keys)
 {
 	if (system_supports_address_auth()) {
 		__ptrauth_key_install(APIA, keys->apia);
@@ -80,12 +80,12 @@ static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr)
 #define ptrauth_thread_init_user(tsk)					\
 do {									\
 	struct task_struct *__ptiu_tsk = (tsk);				\
-	ptrauth_keys_init(&__ptiu_tsk->thread.keys_user);		\
-	ptrauth_keys_switch(&__ptiu_tsk->thread.keys_user);		\
+	ptrauth_keys_init_user(&__ptiu_tsk->thread.keys_user);		\
+	ptrauth_keys_switch_user(&__ptiu_tsk->thread.keys_user);		\
 } while (0)
 
 #define ptrauth_thread_switch(tsk)	\
-	ptrauth_keys_switch(&(tsk)->thread.keys_user)
+	ptrauth_keys_switch_user(&(tsk)->thread.keys_user)
 
 #else /* CONFIG_ARM64_PTR_AUTH */
 #define ptrauth_prctl_reset_keys(tsk, arg)	(-EINVAL)

arch/arm64/include/asm/processor.h

@@ -146,7 +146,7 @@ struct thread_struct {
 	unsigned long		fault_code;	/* ESR_EL1 value */
 	struct debug_info	debug;		/* debugging */
 #ifdef CONFIG_ARM64_PTR_AUTH
-	struct ptrauth_keys	keys_user;
+	struct ptrauth_keys_user	keys_user;
 #endif
 };
 

arch/arm64/kernel/pointer_auth.c

@@ -9,7 +9,7 @@
 
 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;
@@ -18,8 +18,8 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
 		return -EINVAL;
 
 	if (!arg) {
-		ptrauth_keys_init(keys);
-		ptrauth_keys_switch(keys);
+		ptrauth_keys_init_user(keys);
+		ptrauth_keys_switch_user(keys);
 		return 0;
 	}
 
@@ -41,7 +41,7 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
 	if (arg & PR_PAC_APGAKEY)
 		get_random_bytes(&keys->apga, sizeof(keys->apga));
 
-	ptrauth_keys_switch(keys);
+	ptrauth_keys_switch_user(keys);
 
 	return 0;
 }

arch/arm64/kernel/ptrace.c

@@ -999,15 +999,15 @@ static struct ptrauth_key pac_key_from_user(__uint128_t ukey)
 }
 
 static void pac_address_keys_to_user(struct user_pac_address_keys *ukeys,
-				     const struct ptrauth_keys *keys)
+				     const struct ptrauth_keys_user *keys)
 {
 	ukeys->apiakey = pac_key_to_user(&keys->apia);
 	ukeys->apibkey = pac_key_to_user(&keys->apib);
 	ukeys->apdakey = pac_key_to_user(&keys->apda);
 	ukeys->apdbkey = pac_key_to_user(&keys->apdb);
 }
 
-static void pac_address_keys_from_user(struct ptrauth_keys *keys,
+static void pac_address_keys_from_user(struct ptrauth_keys_user *keys,
 				       const struct user_pac_address_keys *ukeys)
 {
 	keys->apia = pac_key_from_user(ukeys->apiakey);
@@ -1021,7 +1021,7 @@ static int pac_address_keys_get(struct task_struct *target,
 				unsigned int pos, unsigned int count,
 				void *kbuf, void __user *ubuf)
 {
-	struct ptrauth_keys *keys = &target->thread.keys_user;
+	struct ptrauth_keys_user *keys = &target->thread.keys_user;
 	struct user_pac_address_keys user_keys;
 
 	if (!system_supports_address_auth())
@@ -1038,7 +1038,7 @@ static int pac_address_keys_set(struct task_struct *target,
 				unsigned int pos, unsigned int count,
 				const void *kbuf, const void __user *ubuf)
 {
-	struct ptrauth_keys *keys = &target->thread.keys_user;
+	struct ptrauth_keys_user *keys = &target->thread.keys_user;
 	struct user_pac_address_keys user_keys;
 	int ret;
 
@@ -1056,12 +1056,12 @@ static int pac_address_keys_set(struct task_struct *target,
 }
 
 static void pac_generic_keys_to_user(struct user_pac_generic_keys *ukeys,
-				     const struct ptrauth_keys *keys)
+				     const struct ptrauth_keys_user *keys)
 {
 	ukeys->apgakey = pac_key_to_user(&keys->apga);
 }
 
-static void pac_generic_keys_from_user(struct ptrauth_keys *keys,
+static void pac_generic_keys_from_user(struct ptrauth_keys_user *keys,
 				       const struct user_pac_generic_keys *ukeys)
 {
 	keys->apga = pac_key_from_user(ukeys->apgakey);
@@ -1072,7 +1072,7 @@ static int pac_generic_keys_get(struct task_struct *target,
 				unsigned int pos, unsigned int count,
 				void *kbuf, void __user *ubuf)
 {
-	struct ptrauth_keys *keys = &target->thread.keys_user;
+	struct ptrauth_keys_user *keys = &target->thread.keys_user;
 	struct user_pac_generic_keys user_keys;
 
 	if (!system_supports_generic_auth())
@@ -1089,7 +1089,7 @@ static int pac_generic_keys_set(struct task_struct *target,
 				unsigned int pos, unsigned int count,
 				const void *kbuf, const void __user *ubuf)
 {
-	struct ptrauth_keys *keys = &target->thread.keys_user;
+	struct ptrauth_keys_user *keys = &target->thread.keys_user;
 	struct user_pac_generic_keys user_keys;
 	int ret;