--- zzzz-none-000/linux-3.10.107/arch/arm64/include/asm/uaccess.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/arm64/include/asm/uaccess.h	2021-02-04 17:41:59.000000000 +0000
@@ -24,7 +24,10 @@
 #include <linux/string.h>
 #include <linux/thread_info.h>
 
+#include <asm/alternative.h>
+#include <asm/cpufeature.h>
 #include <asm/ptrace.h>
+#include <asm/sysreg.h>
 #include <asm/errno.h>
 #include <asm/memory.h>
 #include <asm/compiler.h>
@@ -63,7 +66,7 @@
 	current_thread_info()->addr_limit = fs;
 }
 
-#define segment_eq(a,b)	((a) == (b))
+#define segment_eq(a, b)	((a) == (b))
 
 /*
  * Return 1 if addr < current->addr_limit, 0 otherwise.
@@ -83,7 +86,7 @@
  * Returns 1 if the range is valid, 0 otherwise.
  *
  * This is equivalent to the following test:
- * (u65)addr + (u65)size < (u65)current->addr_limit
+ * (u65)addr + (u65)size <= current->addr_limit
  *
  * This needs 65-bit arithmetic.
  */
@@ -91,7 +94,7 @@
 ({									\
 	unsigned long flag, roksum;					\
 	__chk_user_ptr(addr);						\
-	asm("adds %1, %1, %3; ccmp %1, %4, #2, cc; cset %0, cc"		\
+	asm("adds %1, %1, %3; ccmp %1, %4, #2, cc; cset %0, ls"		\
 		: "=&r" (flag), "=&r" (roksum)				\
 		: "1" (addr), "Ir" (size),				\
 		  "r" (current_thread_info()->addr_limit)		\
@@ -100,6 +103,7 @@
 })
 
 #define access_ok(type, addr, size)	__range_ok(addr, size)
+#define user_addr_max			get_fs
 
 /*
  * The "__xxx" versions of the user access functions do not verify the address
@@ -130,6 +134,8 @@
 do {									\
 	unsigned long __gu_val;						\
 	__chk_user_ptr(ptr);						\
+	asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN,	\
+			CONFIG_ARM64_PAN));				\
 	switch (sizeof(*(ptr))) {					\
 	case 1:								\
 		__get_user_asm("ldrb", "%w", __gu_val, (ptr), (err));	\
@@ -146,7 +152,9 @@
 	default:							\
 		BUILD_BUG();						\
 	}								\
-	(x) = (__typeof__(*(ptr)))__gu_val;				\
+	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
+	asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN,	\
+			CONFIG_ARM64_PAN));				\
 } while (0)
 
 #define __get_user(x, ptr)						\
@@ -166,9 +174,10 @@
 
 #define get_user(x, ptr)						\
 ({									\
-	might_sleep();							\
-	access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) ?			\
-		__get_user((x), (ptr)) :				\
+	__typeof__(*(ptr)) __user *__p = (ptr);				\
+	might_fault();							\
+	access_ok(VERIFY_READ, __p, sizeof(*__p)) ?			\
+		__get_user((x), __p) :					\
 		((x) = 0, -EFAULT);					\
 })
 
@@ -192,6 +201,8 @@
 do {									\
 	__typeof__(*(ptr)) __pu_val = (x);				\
 	__chk_user_ptr(ptr);						\
+	asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN,	\
+			CONFIG_ARM64_PAN));				\
 	switch (sizeof(*(ptr))) {					\
 	case 1:								\
 		__put_user_asm("strb", "%w", __pu_val, (ptr), (err));	\
@@ -208,6 +219,8 @@
 	default:							\
 		BUILD_BUG();						\
 	}								\
+	asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN,	\
+			CONFIG_ARM64_PAN));				\
 } while (0)
 
 #define __put_user(x, ptr)						\
@@ -227,9 +240,10 @@
 
 #define put_user(x, ptr)						\
 ({									\
-	might_sleep();							\
-	access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ?		\
-		__put_user((x), (ptr)) :				\
+	__typeof__(*(ptr)) __user *__p = (ptr);				\
+	might_fault();							\
+	access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ?			\
+		__put_user((x), __p) :					\
 		-EFAULT;						\
 })
 
@@ -238,9 +252,6 @@
 extern unsigned long __must_check __copy_in_user(void __user *to, const void __user *from, unsigned long n);
 extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
 
-extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count);
-extern unsigned long __must_check __strnlen_user(const char __user *s, long n);
-
 static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
 {
 	if (access_ok(VERIFY_READ, from, n))
@@ -274,24 +285,9 @@
 	return n;
 }
 
-static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count)
-{
-	long res = -EFAULT;
-	if (access_ok(VERIFY_READ, src, 1))
-		res = __strncpy_from_user(dst, src, count);
-	return res;
-}
-
-#define strlen_user(s)	strnlen_user(s, ~0UL >> 1)
+extern long strncpy_from_user(char *dest, const char __user *src, long count);
 
-static inline long __must_check strnlen_user(const char __user *s, long n)
-{
-	unsigned long res = 0;
-
-	if (__addr_ok(s))
-		res = __strnlen_user(s, n);
-
-	return res;
-}
+extern __must_check long strlen_user(const char __user *str);
+extern __must_check long strnlen_user(const char __user *str, long n);
 
 #endif /* __ASM_UACCESS_H */