Re: [PATCH] tools/virtio: fix build caused by virtio_ring changes

[Shunsuke Mie <mie@igel.co.jp>]

On 2023/04/10 18:46, Michael S. Tsirkin wrote:
> On Mon, Apr 10, 2023 at 06:24:19PM +0900, Shunsuke Mie wrote:
>> Fix the build dependency for virtio_test. virtio_ring requires
>> container_of_const() and struce device.
>>
>> Signed-off-by: Shunsuke Mie <mie@igel.co.jp>
>> ---
>>   tools/include/linux/container_of.h | 36 ++++++++++++++++++++++++++++++
>>   tools/virtio/linux/compiler.h      |  3 +++
>>   tools/virtio/linux/kernel.h        |  5 +----
>>   tools/virtio/linux/module.h        |  1 +
>>   4 files changed, 41 insertions(+), 4 deletions(-)
>>   create mode 100644 tools/include/linux/container_of.h
>>
>> diff --git a/tools/include/linux/container_of.h b/tools/include/linux/container_of.h
>> new file mode 100644
>> index 000000000000..06e293b7cfda
>> --- /dev/null
>> +++ b/tools/include/linux/container_of.h
>> @@ -0,0 +1,36 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef _LINUX_CONTAINER_OF_H
>> +#define _LINUX_CONTAINER_OF_H
>> +
>> +#include <linux/build_bug.h>
>> +#include <linux/stddef.h>
>> +
>> +/**
>> + * container_of - cast a member of a structure out to the containing structure
>> + * @ptr:	the pointer to the member.
>> + * @type:	the type of the container struct this is embedded in.
>> + * @member:	the name of the member within the struct.
>> + *
>> + * WARNING: any const qualifier of @ptr is lost.
>> + */
>> +#define container_of(ptr, type, member) ({				\
>> +	void *__mptr = (void *)(ptr);					\
>> +	static_assert(__same_type(*(ptr), ((type *)0)->member) ||	\
>> +		      __same_type(*(ptr), void),			\
>> +		      "pointer type mismatch in container_of()");	\
>> +	((type *)(__mptr - offsetof(type, member))); })
>> +
>> +/**
>> + * container_of_const - cast a member of a structure out to the containing
>> + *			structure and preserve the const-ness of the pointer
>> + * @ptr:		the pointer to the member
>> + * @type:		the type of the container struct this is embedded in.
>> + * @member:		the name of the member within the struct.
>> + */
>> +#define container_of_const(ptr, type, member)				\
>> +	_Generic(ptr,							\
>> +		const typeof(*(ptr)) *: ((const type *)container_of(ptr, type, member)),\
>> +		default: ((type *)container_of(ptr, type, member))	\
>> +	)
>> +
>> +#endif	/* _LINUX_CONTAINER_OF_H */
>
> Please just do
> #include "../../../include/linux/container_of.h"
> instead.
Okey, I'll do that.
>
>
>> diff --git a/tools/virtio/linux/compiler.h b/tools/virtio/linux/compiler.h
>> index 2c51bccb97bb..ac27b3ea6e67 100644
>> --- a/tools/virtio/linux/compiler.h
>> +++ b/tools/virtio/linux/compiler.h
>> @@ -8,4 +8,7 @@
>>   #define READ_ONCE(var) (*((volatile typeof(var) *)(&(var))))
>>   
>>   #define __aligned(x) __attribute((__aligned__(x)))
>> +
>> +#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
>> +
>>   #endif
> #include "../../../include/linux/compiler_types.h" instead?
I'll try it.
>> diff --git a/tools/virtio/linux/kernel.h b/tools/virtio/linux/kernel.h
>> index 8b877167933d..3cd20cb92649 100644
>> --- a/tools/virtio/linux/kernel.h
>> +++ b/tools/virtio/linux/kernel.h
>> @@ -10,6 +10,7 @@
>>   #include <stdarg.h>
>>   
>>   #include <linux/compiler.h>
>> +#include <linux/container_of.h>
>>   #include <linux/log2.h>
>>   #include <linux/types.h>
>>   #include <linux/overflow.h>
>> @@ -107,10 +108,6 @@ static inline void free_page(unsigned long addr)
>>   	free((void *)addr);
>>   }
>>   
>> -#define container_of(ptr, type, member) ({			\
>> -	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
>> -	(type *)( (char *)__mptr - offsetof(type,member) );})
>> -
>>   # ifndef likely
>>   #  define likely(x)	(__builtin_expect(!!(x), 1))
>>   # endif
>> diff --git a/tools/virtio/linux/module.h b/tools/virtio/linux/module.h
>> index 9dfa96fea2b2..e2e791dbd104 100644
>> --- a/tools/virtio/linux/module.h
>> +++ b/tools/virtio/linux/module.h
>> @@ -5,3 +5,4 @@
>>   	static __attribute__((unused)) const char *__MODULE_LICENSE_name = \
>>   		__MODULE_LICENSE_value
>>   
>> +struct device;
>
> It's not there in include/linux/module - pls put it in the
> same here where it is for linux.
I understood. I'll add some files that has the definition.
>> -- 
>> 2.25.1

Best regards,

Shunsuke.