5 files changed, 28 insertions, 16 deletions

diff --git a/arch/arm64/include/asm/compiler.h b/arch/arm64/include/asm/compiler.h
index 9033a0b2f46a..b6d1d62474e5 100644
--- a/arch/arm64/include/asm/compiler.h
+++ b/arch/arm64/include/asm/compiler.h
@@ -15,15 +15,33 @@
 #define ptrauth_user_pac_mask()		GENMASK_ULL(54, vabits_actual)
 #define ptrauth_kernel_pac_mask()	GENMASK_ULL(63, vabits_actual)
 
-/* Valid for EL0 TTBR0 and EL1 TTBR1 instruction pointers */
-#define ptrauth_clear_pac(ptr)						\
-	((ptr & BIT_ULL(55)) ? (ptr | ptrauth_kernel_pac_mask()) :	\
-			       (ptr & ~ptrauth_user_pac_mask()))
+#define xpaclri(ptr)							\
+({									\
+	register unsigned long __xpaclri_ptr asm("x30") = (ptr);	\
+									\
+	asm(								\
+	ARM64_ASM_PREAMBLE						\
+	"	hint	#7\n"						\
+	: "+r" (__xpaclri_ptr));					\
+									\
+	__xpaclri_ptr;							\
+})
 
-#if defined(CONFIG_ARM64_PTR_AUTH_KERNEL) &&				\
-    !defined(CONFIG_BUILTIN_RETURN_ADDRESS_STRIPS_PAC)
+#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL
+#define ptrauth_strip_kernel_insn_pac(ptr)	xpaclri(ptr)
+#else
+#define ptrauth_strip_kernel_insn_pac(ptr)	(ptr)
+#endif
+
+#ifdef CONFIG_ARM64_PTR_AUTH
+#define ptrauth_strip_user_insn_pac(ptr)	xpaclri(ptr)
+#else
+#define ptrauth_strip_user_insn_pac(ptr)	(ptr)
+#endif
+
+#if !defined(CONFIG_BUILTIN_RETURN_ADDRESS_STRIPS_PAC)
 #define __builtin_return_address(val)					\
-	(void *)(ptrauth_clear_pac((unsigned long)__builtin_return_address(val)))
+	(void *)(ptrauth_strip_kernel_insn_pac((unsigned long)__builtin_return_address(val)))
 #endif
 
 #endif /* __ASM_COMPILER_H */
diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h
index efb098de3a84..b0665db86aa6 100644
--- a/arch/arm64/include/asm/pointer_auth.h
+++ b/arch/arm64/include/asm/pointer_auth.h
@@ -97,11 +97,6 @@ extern int ptrauth_set_enabled_keys(struct task_struct *tsk, unsigned long keys,
 				    unsigned long enabled);
 extern int ptrauth_get_enabled_keys(struct task_struct *tsk);
 
-static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr)
-{
-	return ptrauth_clear_pac(ptr);
-}
-
 static __always_inline void ptrauth_enable(void)
 {
 	if (!system_supports_address_auth())
@@ -133,7 +128,6 @@ static __always_inline void ptrauth_enable(void)
 #define ptrauth_prctl_reset_keys(tsk, arg)	(-EINVAL)
 #define ptrauth_set_enabled_keys(tsk, keys, enabled)	(-EINVAL)
 #define ptrauth_get_enabled_keys(tsk)	(-EINVAL)
-#define ptrauth_strip_insn_pac(lr)	(lr)
 #define ptrauth_suspend_exit()
 #define ptrauth_thread_init_user()
 #define ptrauth_thread_switch_user(tsk)
diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index 65b196e3ca6c..6d157f32187b 100644
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -38,7 +38,7 @@ user_backtrace(struct frame_tail __user *tail,
 	if (err)
 		return NULL;
 
-	lr = ptrauth_strip_insn_pac(buftail.lr);
+	lr = ptrauth_strip_user_insn_pac(buftail.lr);
 
 	perf_callchain_store(entry, lr);
 
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 71d59b5abede..b5bed62483cb 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -217,7 +217,7 @@ void __show_regs(struct pt_regs *regs)
 
 	if (!user_mode(regs)) {
 		printk("pc : %pS\n", (void *)regs->pc);
-		printk("lr : %pS\n", (void *)ptrauth_strip_insn_pac(lr));
+		printk("lr : %pS\n", (void *)ptrauth_strip_kernel_insn_pac(lr));
 	} else {
 		printk("pc : %016llx\n", regs->pc);
 		printk("lr : %016llx\n", lr);
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index f527fadcb33b..17f66a74c745 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -120,7 +120,7 @@ unwind_next(struct unwind_state *state)
 	if (err)
 		return err;
 
-	state->pc = ptrauth_strip_insn_pac(state->pc);
+	state->pc = ptrauth_strip_kernel_insn_pac(state->pc);
 
 	return unwind_recover_return_address(state);
 }