1 files changed, 28 insertions, 99 deletions

diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 0c89d1bb028..c905e89e19f 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -9,64 +9,16 @@
 #include <asm/uaccess.h>
 
 /*
- * Copy a null terminated string from userspace.
- */
-
-#define __do_strncpy_from_user(dst,src,count,res)			   \
-do {									   \
-	long __d0, __d1, __d2;						   \
-	might_sleep();							   \
-	__asm__ __volatile__(						   \
-		"	testq %1,%1\n"					   \
-		"	jz 2f\n"					   \
-		"0:	lodsb\n"					   \
-		"	stosb\n"					   \
-		"	testb %%al,%%al\n"				   \
-		"	jz 1f\n"					   \
-		"	decq %1\n"					   \
-		"	jnz 0b\n"					   \
-		"1:	subq %1,%0\n"					   \
-		"2:\n"							   \
-		".section .fixup,\"ax\"\n"				   \
-		"3:	movq %5,%0\n"					   \
-		"	jmp 2b\n"					   \
-		".previous\n"						   \
-		_ASM_EXTABLE(0b,3b)					   \
-		: "=r"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1),	   \
-		  "=&D" (__d2)						   \
-		: "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
-		: "memory");						   \
-} while (0)
-
-long
-__strncpy_from_user(char *dst, const char __user *src, long count)
-{
-	long res;
-	__do_strncpy_from_user(dst, src, count, res);
-	return res;
-}
-EXPORT_SYMBOL(__strncpy_from_user);
-
-long
-strncpy_from_user(char *dst, const char __user *src, long count)
-{
-	long res = -EFAULT;
-	if (access_ok(VERIFY_READ, src, 1))
-		return __strncpy_from_user(dst, src, count);
-	return res;
-}
-EXPORT_SYMBOL(strncpy_from_user);
-
-/*
  * Zero Userspace
  */
 
 unsigned long __clear_user(void __user *addr, unsigned long size)
 {
 	long __d0;
-	might_sleep();
+	might_fault();
 	/* no memory constraint because it doesn't change any memory gcc knows
 	   about */
+	stac();
 	asm volatile(
 		"	testq  %[size8],%[size8]\n"
 		"	jz     4f\n"
@@ -86,9 +38,10 @@ unsigned long __clear_user(void __user *addr, unsigned long size)
 		".previous\n"
 		_ASM_EXTABLE(0b,3b)
 		_ASM_EXTABLE(1b,2b)
-		: [size8] "=c"(size), [dst] "=&D" (__d0)
+		: [size8] "=&c"(size), [dst] "=&D" (__d0)
 		: [size1] "r"(size & 7), "[size8]" (size / 8), "[dst]"(addr),
 		  [zero] "r" (0UL), [eight] "r" (8UL));
+	clac();
 	return size;
 }
 EXPORT_SYMBOL(__clear_user);
@@ -101,54 +54,6 @@ unsigned long clear_user(void __user *to, unsigned long n)
 }
 EXPORT_SYMBOL(clear_user);
 
-/*
- * Return the size of a string (including the ending 0)
- *
- * Return 0 on exception, a value greater than N if too long
- */
-
-long __strnlen_user(const char __user *s, long n)
-{
-	long res = 0;
-	char c;
-
-	while (1) {
-		if (res>n)
-			return n+1;
-		if (__get_user(c, s))
-			return 0;
-		if (!c)
-			return res+1;
-		res++;
-		s++;
-	}
-}
-EXPORT_SYMBOL(__strnlen_user);
-
-long strnlen_user(const char __user *s, long n)
-{
-	if (!access_ok(VERIFY_READ, s, n))
-		return 0;
-	return __strnlen_user(s, n);
-}
-EXPORT_SYMBOL(strnlen_user);
-
-long strlen_user(const char __user *s)
-{
-	long res = 0;
-	char c;
-
-	for (;;) {
-		if (get_user(c, s))
-			return 0;
-		if (!c)
-			return res+1;
-		res++;
-		s++;
-	}
-}
-EXPORT_SYMBOL(strlen_user);
-
 unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len)
 {
 	if (access_ok(VERIFY_WRITE, to, len) && access_ok(VERIFY_READ, from, len)) { 
@@ -158,3 +63,27 @@ unsigned long copy_in_user(void __user *to, const void __user *from, unsigned le
 }
 EXPORT_SYMBOL(copy_in_user);
 
+/*
+ * Try to copy last bytes and clear the rest if needed.
+ * Since protection fault in copy_from/to_user is not a normal situation,
+ * it is not necessary to optimize tail handling.
+ */
+__visible unsigned long
+copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest)
+{
+	char c;
+	unsigned zero_len;
+
+	for (; len; --len, to++) {
+		if (__get_user_nocheck(c, from++, sizeof(char)))
+			break;
+		if (__put_user_nocheck(c, to, sizeof(char)))
+			break;
+	}
+
+	for (c = 0, zero_len = len; zerorest && zero_len; --zero_len)
+		if (__put_user_nocheck(c, to++, sizeof(char)))
+			break;
+	clac();
+	return len;
+}