Re: ioctl, compat_ioctl and ioctl32

[James Hansen <debian-amd64@f0rmula.com>]

James Hansen wrote:

> I'm having trouble inserting a module into the kernel.  It was 
> originally written for a 32bit architecture, as were the binaries that 
> use it, and the kernel seems to be calling ioctl32 rather than ioctl.
>
> ioctl32(app:2342): Unknown cmd fd(7) etc etc.
>
> I imagine this is to allow the 32bit binaries (and libraries) to use 
> the 64bit kernel, allowing for some conversion to take place.
>
> The problem is when building the module, if I add an entry to my fops 
> struct for ioctl32 (or from a little bit of research 'compat_ioctl'), 
> it complains that this is an unknown field in the kernel's fops struct.
>
> I'm using the default kernel btw.  Would anyone know why I'm unable to 
> add this field to the struct?  Or could anyone refer me to anything 
> that might explain things?
>
> Thanks a lot
>
> James
I've just had a look in the kernel-headers directory for the default 
kernel.  There is definately no entry for ioctl32 or compat_ioctl in the 
file_operations struct. 

How come it's calling ioctl32, when I'm unable to specify anything for it?

Thanks

James

struct file_operations {
       struct module *owner;
       loff_t (*llseek) (struct file *, loff_t, int);
       ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
       ssize_t (*aio_read) (struct kiocb *, char __user *, size_t, loff_t);
       ssize_t (*write) (struct file *, const char __user *, size_t, 
loff_t *);
       ssize_t (*aio_write) (struct kiocb *, const char __user *, 
size_t, loff_t);
       int (*readdir) (struct file *, void *, filldir_t);
       unsigned int (*poll) (struct file *, struct poll_table_struct *);
       int (*ioctl) (struct inode *, struct file *, unsigned int, 
unsigned long);
       int (*mmap) (struct file *, struct vm_area_struct *);
       int (*open) (struct inode *, struct file *);
       int (*flush) (struct file *);
       int (*release) (struct inode *, struct file *);
       int (*fsync) (struct file *, struct dentry *, int datasync);
       int (*aio_fsync) (struct kiocb *, int datasync);
       int (*fasync) (int, struct file *, int);
       int (*lock) (struct file *, int, struct file_lock *);
       ssize_t (*readv) (struct file *, const struct iovec *, unsigned 
long, loff_t *);
       ssize_t (*writev) (struct file *, const struct iovec *, unsigned 
long, loff_t *);
       ssize_t (*sendfile) (struct file *, loff_t *, size_t, 
read_actor_t, void *);
       ssize_t (*sendpage) (struct file *, struct page *, int, size_t, 
loff_t *, int);
       unsigned long (*get_unmapped_area)(struct file *, unsigned long, 
unsigned long, unsigned long, unsigned long);
       int (*check_flags)(int);
       int (*dir_notify)(struct file *filp, unsigned long arg);
};