nios2: drop access_ok() check from __put_user()

Unlike other architectures, the nios2 version of __put_user() has an
extra check for access_ok(), preventing it from being used to implement
__put_kernel_nofault().

Split up put_user() along the same lines as __get_user()/get_user()

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Arnd Bergmann 2022-02-15 11:24:27 +01:00
parent 1830a1d6a5
commit 90997c1280

View File

@ -167,34 +167,44 @@ do { \
: "r" (val), "r" (ptr), "i" (-EFAULT)); \
}
#define put_user(x, ptr) \
#define __put_user_common(__pu_val, __pu_ptr) \
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
__typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \
if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) { \
switch (sizeof(*__pu_ptr)) { \
case 1: \
__put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
break; \
case 2: \
__put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
break; \
case 4: \
__put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
break; \
default: \
/* XXX: This looks wrong... */ \
__pu_err = 0; \
if (copy_to_user(__pu_ptr, &(__pu_val), \
sizeof(*__pu_ptr))) \
__pu_err = -EFAULT; \
break; \
} \
switch (sizeof(*__pu_ptr)) { \
case 1: \
__put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
break; \
case 2: \
__put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
break; \
case 4: \
__put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
break; \
default: \
/* XXX: This looks wrong... */ \
__pu_err = 0; \
if (__copy_to_user(__pu_ptr, &(__pu_val), \
sizeof(*__pu_ptr))) \
__pu_err = -EFAULT; \
break; \
} \
__pu_err; \
})
#define __put_user(x, ptr) put_user(x, ptr)
#define __put_user(x, ptr) \
({ \
__auto_type __pu_ptr = (ptr); \
typeof(*__pu_ptr) __pu_val = (typeof(*__pu_ptr))(x); \
__put_user_common(__pu_val, __pu_ptr); \
})
#define put_user(x, ptr) \
({ \
__auto_type __pu_ptr = (ptr); \
typeof(*__pu_ptr) __pu_val = (typeof(*__pu_ptr))(x); \
access_ok(__pu_ptr, sizeof(*__pu_ptr)) ? \
__put_user_common(__pu_val, __pu_ptr) : \
-EFAULT; \
})
#endif /* _ASM_NIOS2_UACCESS_H */