Re: syscall help

[Tyler <tyler@xxxxxxxx>]

Athul Acharya wrote:
> Hey folks,
>
> How do I (in a syscall) check that an address passed to me is in the
> user's address space?
>
> Athul
>
> --
> Kernelnewbies: Help each other learn about the Linux kernel.
> Archive:       http://mail.nl.linux.org/kernelnewbies/
> FAQ:           http://kernelnewbies.org/faq/
You can get the differents memory regions of the process by the 
following fields :
current->mmap, current->mmap_avl and current->mmap_cache. These fields 
are struct vm_area_struct type.

struct vm_area_struct{
	unsigned long vm_start ;
	unsigned long vm_end ;
	....
};

So you cab check every region of the current process and see if the 
adress passed exists in memory space of the process.

But are you sure you need to do this test ?
try to use the functions get_users and verify the data after. Should be 
better.



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Archive:       http://mail.nl.linux.org/kernelnewbies/
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