powerpc/uaccess: Refactor get/put_user() and __get/put_user()

Make get_user() do the access_ok() check then call __get_user().
Make put_user() do the access_ok() check then call __put_user().

Then embed  __get_user_size() and __put_user_size() in
__get_user() and __put_user().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eebc554f6a81f570c46ea3551000ff5b886e4faa.1615398265.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 065af18..9612889 100644 (file)
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -43,21 +43,6 @@ static inline bool __access_ok(unsigned long addr, unsigned long size)
  * exception handling means that it's no longer "just"...)
  *
  */
-#define __put_user_size(x, ptr, size, retval)                  \
-do {                                                           \
-       __label__ __pu_failed;                                  \
-                                                               \
-       retval = 0;                                             \
-       allow_write_to_user(ptr, size);                         \
-       __put_user_size_goto(x, ptr, size, __pu_failed);        \
-       prevent_write_to_user(ptr, size);                       \
-       break;                                                  \
-                                                               \
-__pu_failed:                                                   \
-       retval = -EFAULT;                                       \
-       prevent_write_to_user(ptr, size);                       \
-} while (0)
-
 #define __put_user(x, ptr)                                     \
 ({                                                             \
        long __pu_err;                                          \
@@ -66,23 +51,29 @@ __pu_failed:                                                        \
        __typeof__(sizeof(*(ptr))) __pu_size = sizeof(*(ptr));  \
                                                                \
        might_fault();                                          \
-       __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err);      \
+       do {                                                    \
+               __label__ __pu_failed;                          \
+                                                               \
+               allow_write_to_user(__pu_addr, __pu_size);      \
+               __put_user_size_goto(__pu_val, __pu_addr, __pu_size, __pu_failed);      \
+               prevent_write_to_user(__pu_addr, __pu_size);    \
+               __pu_err = 0;                                   \
+               break;                                          \
+                                                               \
+__pu_failed:                                                   \
+               prevent_write_to_user(__pu_addr, __pu_size);    \
+               __pu_err = -EFAULT;                             \
+       } while (0);                                            \
                                                                \
        __pu_err;                                               \
 })
 
 #define put_user(x, ptr)                                               \
 ({                                                                     \
-       long __pu_err = -EFAULT;                                        \
-       __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
-       __typeof__(*(ptr)) __pu_val = (__typeof__(*(ptr)))(x);          \
-       __typeof__(sizeof(*(ptr))) __pu_size = sizeof(*(ptr));          \
+       __typeof__(*(ptr)) __user *_pu_addr = (ptr);                    \
                                                                        \
-       might_fault();                                                  \
-       if (access_ok(__pu_addr, __pu_size))                            \
-               __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \
-                                                                       \
-       __pu_err;                                                       \
+       access_ok(_pu_addr, sizeof(*(ptr))) ?                           \
+                 __put_user(x, _pu_addr) : -EFAULT;                    \
 })
 
 /*
@@ -192,13 +183,6 @@ do {                                                               \
        }                                                       \
 } while (0)
 
-#define __get_user_size(x, ptr, size, retval)                  \
-do {                                                           \
-       allow_read_from_user(ptr, size);                        \
-       __get_user_size_allowed(x, ptr, size, retval);          \
-       prevent_read_from_user(ptr, size);                      \
-} while (0)
-
 /*
  * This is a type: either unsigned long, if the argument fits into
  * that type, or otherwise unsigned long long.
@@ -214,7 +198,9 @@ do {                                                                \
        __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr));  \
                                                                \
        might_fault();                                  \
-       __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err);      \
+       allow_read_from_user(__gu_addr, __gu_size);             \
+       __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err);      \
+       prevent_read_from_user(__gu_addr, __gu_size);           \
        (x) = (__typeof__(*(ptr)))__gu_val;                     \
                                                                \
        __gu_err;                                               \
@@ -222,17 +208,11 @@ do {                                                              \
 
 #define get_user(x, ptr)                                               \
 ({                                                                     \
-       long __gu_err = -EFAULT;                                        \
-       __long_type(*(ptr)) __gu_val = 0;                               \
-       __typeof__(*(ptr)) __user *__gu_addr = (ptr);           \
-       __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr));          \
-                                                                       \
-       might_fault();                                                  \
-       if (access_ok(__gu_addr, __gu_size))                            \
-               __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \
-       (x) = (__force __typeof__(*(ptr)))__gu_val;                             \
+       __typeof__(*(ptr)) __user *_gu_addr = (ptr);                    \
                                                                        \
-       __gu_err;                                                       \
+       access_ok(_gu_addr, sizeof(*(ptr))) ?                           \
+                 __get_user(x, _gu_addr) :                             \
+                 ((x) = (__force __typeof__(*(ptr)))0, -EFAULT);       \
 })
 
 /* more complex routines */