diff options
| -rw-r--r-- | arch/x86/lib/usercopy.c | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index d6ae30bbd7bb..2e4e4b02c37a 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -44,13 +44,6 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) } 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 @@ -69,16 +62,19 @@ static inline long do_strncpy_from_user(char *dst, const char __user *src, long max = count; while (max >= sizeof(unsigned long)) { - unsigned long c; + unsigned long c, mask; /* 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 */ + mask = has_zero(c); + if (mask) { + mask = (mask - 1) & ~mask; + mask >>= 7; + *(unsigned long *)(dst+res) = c & mask; + return res + count_masked_bytes(mask); + } *(unsigned long *)(dst+res) = c; - c = has_zero(c); - if (c) - return res + count_bytes(c); res += sizeof(unsigned long); max -= sizeof(unsigned long); } |