uaccess: fix nios2 and microblaze get_user_8()

These two architectures implement 8-byte get_user() through
a memcpy() into a four-byte variable, which won't fit.

Use a temporary 64-bit variable instead here, and use a double
cast the way that risc-v and openrisc do to avoid compile-time
warnings.

Fixes: 6a090e97972d ("arch/microblaze: support get_user() of size 8 bytes")
Fixes: 5ccc6af5e88e ("nios2: Memory management")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index 5b6e0e7788f4475b14f9d922b94e33ba964e6d3e..3fe96979d2c62418f5b00fa56ea2fd8a480d5051 100644 (file)
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -130,27 +130,27 @@ extern long __user_bad(void);
 
 #define __get_user(x, ptr)                                             \
 ({                                                                     \
-       unsigned long __gu_val = 0;                                     \
        long __gu_err;                                                  \
        switch (sizeof(*(ptr))) {                                       \
        case 1:                                                         \
-               __get_user_asm("lbu", (ptr), __gu_val, __gu_err);       \
+               __get_user_asm("lbu", (ptr), x, __gu_err);              \
                break;                                                  \
        case 2:                                                         \
-               __get_user_asm("lhu", (ptr), __gu_val, __gu_err);       \
+               __get_user_asm("lhu", (ptr), x, __gu_err);              \
                break;                                                  \
        case 4:                                                         \
-               __get_user_asm("lw", (ptr), __gu_val, __gu_err);        \
+               __get_user_asm("lw", (ptr), x, __gu_err);               \
                break;                                                  \
-       case 8:                                                         \
-               __gu_err = __copy_from_user(&__gu_val, ptr, 8);         \
-               if (__gu_err)                                           \
-                       __gu_err = -EFAULT;                             \
+       case 8: {                                                       \
+               __u64 __x = 0;                                          \
+               __gu_err = raw_copy_from_user(&__x, ptr, 8) ?           \
+                                                       -EFAULT : 0;    \
+               (x) = (typeof(x))(typeof((x) - (x)))__x;                \
                break;                                                  \
+       }                                                               \
        default:                                                        \
                /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
        }                                                               \
-       x = (__force __typeof__(*(ptr))) __gu_val;                      \
        __gu_err;                                                       \
 })
 

diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h
index ba9340e96fd4c0fd076513702d964b89e3d41fdd..ca9285a915efaaf253ed273b08a393208cd05d8c 100644 (file)
--- a/arch/nios2/include/asm/uaccess.h
+++ b/arch/nios2/include/asm/uaccess.h
@@ -88,6 +88,7 @@ extern __must_check long strnlen_user(const char __user *s, long n);
 /* Optimized macros */
 #define __get_user_asm(val, insn, addr, err)                           \
 {                                                                      \
+       unsigned long __gu_val;                                         \
        __asm__ __volatile__(                                           \
        "       movi    %0, %3\n"                                       \
        "1:   " insn " %1, 0(%2)\n"                                     \
@@ -96,14 +97,20 @@ extern __must_check long strnlen_user(const char __user *s, long n);
        "       .section __ex_table,\"a\"\n"                            \
        "       .word 1b, 2b\n"                                         \
        "       .previous"                                              \
-       : "=&r" (err), "=r" (val)                                       \
+       : "=&r" (err), "=r" (__gu_val)                                  \
        : "r" (addr), "i" (-EFAULT));                                   \
+       val = (__force __typeof__(*(addr)))__gu_val;                    \
 }
 
-#define __get_user_unknown(val, size, ptr, err) do {                   \
+extern void __get_user_unknown(void);
+
+#define __get_user_8(val, ptr, err) do {                               \
+       u64 __val = 0;                                                  \
        err = 0;                                                        \
-       if (__copy_from_user(&(val), ptr, size)) {                      \
+       if (raw_copy_from_user(&(__val), ptr, sizeof(val))) {           \
                err = -EFAULT;                                          \
+       } else {                                                        \
+               val = (typeof(val))(typeof((val) - (val)))__val;        \
        }                                                               \
        } while (0)
 
@@ -119,8 +126,11 @@ do {                                                                       \
        case 4:                                                         \
                __get_user_asm(val, "ldw", ptr, err);                   \
                break;                                                  \
+       case 8:                                                         \
+               __get_user_8(val, ptr, err);                            \
+               break;                                                  \
        default:                                                        \
-               __get_user_unknown(val, size, ptr, err);                \
+               __get_user_unknown();                                   \
                break;                                                  \
        }                                                               \
 } while (0)
@@ -129,9 +139,7 @@ do {                                                                        \
        ({                                                              \
        long __gu_err = -EFAULT;                                        \
        const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);              \
-       unsigned long __gu_val = 0;                                     \
-       __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
-       (x) = (__force __typeof__(x))__gu_val;                          \
+       __get_user_common(x, sizeof(*(ptr)), __gu_ptr, __gu_err);       \
        __gu_err;                                                       \
        })
 
@@ -139,11 +147,9 @@ do {                                                                       \
 ({                                                                     \
        long __gu_err = -EFAULT;                                        \
        const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);              \
-       unsigned long __gu_val = 0;                                     \
        if (access_ok( __gu_ptr, sizeof(*__gu_ptr)))    \
-               __get_user_common(__gu_val, sizeof(*__gu_ptr),          \
+               __get_user_common(x, sizeof(*__gu_ptr),                 \
                        __gu_ptr, __gu_err);                            \
-       (x) = (__force __typeof__(x))__gu_val;                          \
        __gu_err;                                                       \
 })