Merge remote-tracking branch 'lts/linux-4.4.y' into linux-linaro-lsk-v4.4

[firefly-linux-kernel-4.4.55.git] / lib / strncpy_from_user.c

diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index e0af6ff73d146cfa3356080ebcb1bbea36cd1f96..5a003a2ebd967cfe6a9e202ea9a1ae7f1ddf1aba 100644 (file)
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -39,8 +39,8 @@ static inline long do_strncpy_from_user(char *dst, const char __user *src, long
                unsigned long c, data;
 
                /* Fall back to byte-at-a-time if we get a page fault */
-               if (unlikely(__get_user(c,(unsigned long __user *)(src+res))))
-                       break;
+               unsafe_get_user(c, (unsigned long __user *)(src+res), byte_at_a_time);
+
                *(unsigned long *)(dst+res) = c;
                if (has_zero(c, &data, &constants)) {
                        data = prep_zero_mask(c, data, &constants);
@@ -55,8 +55,7 @@ byte_at_a_time:
        while (max) {
                char c;
 
-               if (unlikely(__get_user(c,src+res)))
-                       return -EFAULT;
+               unsafe_get_user(c,src+res, efault);
                dst[res] = c;
                if (!c)
                        return res;
@@ -75,6 +74,7 @@ byte_at_a_time:
         * Nope: we hit the address space limit, and we still had more
         * characters the caller would have wanted. That's an EFAULT.
         */
+efault:
        return -EFAULT;
 }
 
@@ -107,7 +107,12 @@ long strncpy_from_user(char *dst, const char __user *src, long count)
        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);
+               long retval;
+
+               user_access_begin();
+               retval = do_strncpy_from_user(dst, src, count, max);
+               user_access_end();
+               return retval;
        }
        return -EFAULT;
 }