diff options
Diffstat (limited to 'lib/strncpy_from_user.c')
| -rw-r--r-- | lib/strncpy_from_user.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index bb2b201d6ad0..dfa554cc1a5f 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -1,4 +1,5 @@ #include <linux/module.h> +#include <linux/thread_info.h> #include <linux/uaccess.h> #include <linux/kernel.h> #include <linux/errno.h> @@ -38,8 +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); @@ -54,8 +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; @@ -74,6 +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; } @@ -106,7 +107,13 @@ 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; + + check_object_size(dst, count, false); + user_access_begin(); + retval = do_strncpy_from_user(dst, src, count, max); + user_access_end(); + return retval; } return -EFAULT; } |