asm-generic: zero in __get_user(), not __get_user_fn()
authorAl Viro <viro@zeniv.linux.org.uk>
Tue, 28 Mar 2017 05:02:40 +0000 (01:02 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Tue, 28 Mar 2017 20:43:45 +0000 (16:43 -0400)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
include/asm-generic/uaccess.h

index b048246a606b3b4c6f77ea3f584707921f6c69a6..bd7a05e9582b40193922b9c639110f72ff36f685 100644 (file)
@@ -86,8 +86,7 @@ static inline int __access_ok(unsigned long addr, unsigned long size)
 
 static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
 {
-       size = __copy_to_user(ptr, x, size);
-       return size ? -EFAULT : size;
+       return unlikely(__copy_to_user(ptr, x, size)) ? -EFAULT : 0;
 }
 
 #define __put_user_fn(sz, u, k)        __put_user_fn(sz, u, k)
@@ -102,28 +101,28 @@ extern int __put_user_bad(void) __attribute__((noreturn));
        __chk_user_ptr(ptr);                                    \
        switch (sizeof(*(ptr))) {                               \
        case 1: {                                               \
-               unsigned char __x;                              \
+               unsigned char __x = 0;                          \
                __gu_err = __get_user_fn(sizeof (*(ptr)),       \
                                         ptr, &__x);            \
                (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
                break;                                          \
        };                                                      \
        case 2: {                                               \
-               unsigned short __x;                             \
+               unsigned short __x = 0;                         \
                __gu_err = __get_user_fn(sizeof (*(ptr)),       \
                                         ptr, &__x);            \
                (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
                break;                                          \
        };                                                      \
        case 4: {                                               \
-               unsigned int __x;                               \
+               unsigned int __x = 0;                           \
                __gu_err = __get_user_fn(sizeof (*(ptr)),       \
                                         ptr, &__x);            \
                (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
                break;                                          \
        };                                                      \
        case 8: {                                               \
-               unsigned long long __x;                         \
+               unsigned long long __x = 0;                     \
                __gu_err = __get_user_fn(sizeof (*(ptr)),       \
                                         ptr, &__x);            \
                (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
@@ -148,12 +147,7 @@ extern int __put_user_bad(void) __attribute__((noreturn));
 #ifndef __get_user_fn
 static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
 {
-       size_t n = __copy_from_user(x, ptr, size);
-       if (unlikely(n)) {
-               memset(x + (size - n), 0, n);
-               return -EFAULT;
-       }
-       return 0;
+       return unlikely(__copy_from_user(x, ptr, size)) ? -EFAULT : 0;
 }
 
 #define __get_user_fn(sz, u, k)        __get_user_fn(sz, u, k)