[PATCHv3 12/17] arm64: uaccess: split user/kernel routines

[Mark Rutland]

On Mon, Oct 26, 2020 at 01:31:51PM +0000, Mark Rutland wrote:
> -#define __raw_get_mem(x, ptr, err)					\
> +#define __raw_get_mem(ldr, x, ptr, err)					\
>  do {									\
>  	unsigned long __gu_val;						\
>  	__chk_user_ptr(ptr);						\
>  	switch (sizeof(*(ptr))) {					\
>  	case 1:								\
> -		__get_mem_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr),	\
> -			       (err), ARM64_HAS_UAO);			\
> +		__get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err));	\
>  		break;							\
>  	case 2:								\
> -		__get_mem_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr),	\
> -			       (err), ARM64_HAS_UAO);			\
> +		__get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err));	\
>  		break;							\
>  	case 4:								\
> -		__get_mem_asm("ldr", "ldtr", "%w", __gu_val, (ptr),	\
> -			       (err), ARM64_HAS_UAO);			\
> +		__get_mem_asm(ldr, "%w", __gu_val, (ptr), (err));	\
>  		break;							\
>  	case 8:								\
> -		__get_mem_asm("ldr", "ldtr", "%x",  __gu_val, (ptr),	\
> -			       (err), ARM64_HAS_UAO);			\
> +		__get_mem_asm(ldr, "%x",  __gu_val, (ptr), (err));	\
>  		break;							\
>  	default:							\
>  		BUILD_BUG();						\
> @@ -298,7 +295,7 @@ do {									\
>  #define __raw_get_user(x, ptr, err)					\
>  do {									\
>  	uaccess_enable_not_uao();					\
> -	__raw_get_mem(x, ptr, err);					\
> +	__raw_get_mem("ldtr", x, ptr, err);				\
>  	uaccess_disable_not_uao();					\
>  } while (0)
>  
> @@ -323,10 +320,19 @@ do {									\
>  
>  #define get_user	__get_user
>  
> -#define __put_mem_asm(instr, alt_instr, reg, x, addr, err, feature)	\
> +#define __get_kernel_nofault(dst, src, type, err_label)			\
> +do {									\
> +	int __gkn_err;							\
> +									\
> +	__raw_get_mem("ldr", *((type *)(dst)),				\
> +		      (__force type __user *)(src), __gkn_err);		\
> +	if (unlikely(__gkn_err))					\
> +		goto err_label;						\
> +} while(0)

The `__gkn_err` variables needs to be initialized to zero to avoid
spurious errors being returned.

> @@ -366,7 +368,7 @@ do {									\
>  #define __raw_put_user(x, ptr, err)					\
>  do {									\
>  	uaccess_enable_not_uao();					\
> -	__raw_put_mem(x, ptr, err);					\
> +	__raw_put_mem("sttr", x, ptr, err);				\
>  	uaccess_disable_not_uao();					\
>  } while (0)
>  
> @@ -391,6 +393,16 @@ do {									\
>  
>  #define put_user	__put_user
>  
> +#define __put_kernel_nofault(dst, src, type, err_label)			\
> +do {									\
> +	int __pkn_err;							\
> +									\
> +	__raw_put_mem("str", *((type *)(src)),				\
> +		      (__force type __user *)(dst), __pkn_err);		\
> +	if (unlikely(__pkn_err))					\
> +		goto err_label;						\
> +} while(0)

... and likewise here.

I've fixed both in my tree.

Mark.