1 files changed, 4 insertions, 101 deletions

diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index d6ae30bbd7bb..4f74d94c8d97 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -8,6 +8,7 @@
 #include <linux/module.h>
 
 #include <asm/word-at-a-time.h>
+#include <linux/sched.h>
 
 /*
  * best effort, GUP based copy_from_user() that is NMI-safe
@@ -21,6 +22,9 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
 	void *map;
 	int ret;
 
+	if (__range_not_ok(from, n, TASK_SIZE))
+		return len;
+
 	do {
 		ret = __get_user_pages_fast(addr, 1, 0, &page);
 		if (!ret)
@@ -43,104 +47,3 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
 	return len;
 }
 EXPORT_SYMBOL_GPL(copy_from_user_nmi);
-
-static inline unsigned long count_bytes(unsigned long mask)
-{
-	mask = (mask - 1) & ~mask;
-	mask >>= 7;
-	return count_masked_bytes(mask);
-}
-
-/*
- * Do a strncpy, return length of string without final '\0'.
- * 'count' is the user-supplied count (return 'count' if we
- * hit it), 'max' is the address space maximum (and we return
- * -EFAULT if we hit it).
- */
-static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max)
-{
-	long res = 0;
-
-	/*
-	 * Truncate 'max' to the user-specified limit, so that
-	 * we only have one limit we need to check in the loop
-	 */
-	if (max > count)
-		max = count;
-
-	while (max >= sizeof(unsigned long)) {
-		unsigned long c;
-
-		/* Fall back to byte-at-a-time if we get a page fault */
-		if (unlikely(__get_user(c,(unsigned long __user *)(src+res))))
-			break;
-		/* This can write a few bytes past the NUL character, but that's ok */
-		*(unsigned long *)(dst+res) = c;
-		c = has_zero(c);
-		if (c)
-			return res + count_bytes(c);
-		res += sizeof(unsigned long);
-		max -= sizeof(unsigned long);
-	}
-
-	while (max) {
-		char c;
-
-		if (unlikely(__get_user(c,src+res)))
-			return -EFAULT;
-		dst[res] = c;
-		if (!c)
-			return res;
-		res++;
-		max--;
-	}
-
-	/*
-	 * Uhhuh. We hit 'max'. But was that the user-specified maximum
-	 * too? If so, that's ok - we got as much as the user asked for.
-	 */
-	if (res >= count)
-		return res;
-
-	/*
-	 * Nope: we hit the address space limit, and we still had more
-	 * characters the caller would have wanted. That's an EFAULT.
-	 */
-	return -EFAULT;
-}
-
-/**
- * strncpy_from_user: - Copy a NUL terminated string from userspace.
- * @dst:   Destination address, in kernel space.  This buffer must be at
- *         least @count bytes long.
- * @src:   Source address, in user space.
- * @count: Maximum number of bytes to copy, including the trailing NUL.
- *
- * Copies a NUL-terminated string from userspace to kernel space.
- *
- * On success, returns the length of the string (not including the trailing
- * NUL).
- *
- * If access to userspace fails, returns -EFAULT (some data may have been
- * copied).
- *
- * If @count is smaller than the length of the string, copies @count bytes
- * and returns @count.
- */
-long
-strncpy_from_user(char *dst, const char __user *src, long count)
-{
-	unsigned long max_addr, src_addr;
-
-	if (unlikely(count <= 0))
-		return 0;
-
-	max_addr = current_thread_info()->addr_limit.seg;
-	src_addr = (unsigned long)src;
-	if (likely(src_addr < max_addr)) {
-		unsigned long max = max_addr - src_addr;
-		return do_strncpy_from_user(dst, src, count, max);
-	}
-	return -EFAULT;
-}
-EXPORT_SYMBOL(strncpy_from_user);