Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck...

[cascardo/linux.git] / arch / s390 / include / asm / uaccess.h

diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 9b49cf1..52d7c87 100644 (file)
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -266,28 +266,28 @@ 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(&__x, ptr,             \
                                         sizeof(*(ptr)));       \
                (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
                break;                                          \
        };                                                      \
        case 2: {                                               \
-               unsigned short __x;                             \
+               unsigned short __x = 0;                         \
                __gu_err = __get_user_fn(&__x, ptr,             \
                                         sizeof(*(ptr)));       \
                (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
                break;                                          \
        };                                                      \
        case 4: {                                               \
-               unsigned int __x;                               \
+               unsigned int __x = 0;                           \
                __gu_err = __get_user_fn(&__x, ptr,             \
                                         sizeof(*(ptr)));       \
                (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
                break;                                          \
        };                                                      \
        case 8: {                                               \
-               unsigned long long __x;                         \
+               unsigned long long __x = 0;                     \
                __gu_err = __get_user_fn(&__x, ptr,             \
                                         sizeof(*(ptr)));       \
                (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
@@ -311,6 +311,14 @@ int __get_user_bad(void) __attribute__((noreturn));
 #define __put_user_unaligned __put_user
 #define __get_user_unaligned __get_user
 
+extern void __compiletime_error("usercopy buffer size is too small")
+__bad_copy_user(void);
+
+static inline void copy_user_overflow(int size, unsigned long count)
+{
+       WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
+}
+
 /**
  * copy_to_user: - Copy a block of data into user space.
  * @to:   Destination address, in user space.
@@ -332,12 +340,6 @@ copy_to_user(void __user *to, const void *from, unsigned long n)
        return __copy_to_user(to, from, n);
 }
 
-void copy_from_user_overflow(void)
-#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
-__compiletime_warning("copy_from_user() buffer size is not provably correct")
-#endif
-;
-
 /**
  * copy_from_user: - Copy a block of data from user space.
  * @to:   Destination address, in kernel space.
@@ -362,7 +364,10 @@ copy_from_user(void *to, const void __user *from, unsigned long n)
 
        might_fault();
        if (unlikely(sz != -1 && sz < n)) {
-               copy_from_user_overflow();
+               if (!__builtin_constant_p(n))
+                       copy_user_overflow(sz, n);
+               else
+                       __bad_copy_user();
                return n;
        }
        return __copy_from_user(to, from, n);