Re: [PATCH] autofs4 - fix comms packet struct size

[Christoph Hellwig <hch@infradead.org>]

On Sun, Feb 19, 2006 at 10:11:31PM +0800, Ian Kent wrote:
> 
> Set userspace communication struct fields to fixed size.
> 
> Signed-off-by: Ian Kent <raven@themaw.net>
> 
> --- linux-2.6.16-rc3-mm1/include/linux/auto_fs4.h.fix-v5-packet-size	2006-02-17 19:15:49.000000000 +0800
> +++ linux-2.6.16-rc3-mm1/include/linux/auto_fs4.h	2006-02-17 19:12:09.000000000 +0800
> @@ -65,10 +65,10 @@ struct autofs_v5_packet {
>  	autofs_wqt_t wait_queue_token;

Hiding types in user visible structures behind typedefs is bad.
What type is behind this?  If this is not an __u32 you have
a padding issue.

>  	__u32 dev;
>  	__u64 ino;
> -	uid_t uid;
> -	gid_t gid;
> -	pid_t pid;
> -	pid_t tgid;
> +	__u64 uid;
> +	__u64 gid;
> +	__u64 pid;
> +	__u64 tgid;

These should be 32bit values.

>  	int len;

this should become a fixed-size type aswell.

>  	char name[NAME_MAX+1];
>  };
> --- linux-2.6.16-rc3-mm1/fs/autofs4/autofs_i.h.fix-v5-packet-size	2006-02-17 19:17:03.000000000 +0800
> +++ linux-2.6.16-rc3-mm1/fs/autofs4/autofs_i.h	2006-02-17 19:17:25.000000000 +0800
> @@ -79,10 +79,10 @@ struct autofs_wait_queue {
>  	char *name;
>  	u32 dev;
>  	u64 ino;
> -	uid_t uid;
> -	gid_t gid;
> -	pid_t pid;
> -	pid_t tgid;
> +	u64 uid;
> +	u64 gid;
> +	u64 pid;
> +	u64 tgid;
>  	/* This is for status reporting upon return */
>  	int status;
>  	atomic_t notified;

This is an in-kernel structure, isn't it?  No need to use u64 here.