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Subject: Re: [CHECKER] potential dereference of user pointer errors
From: "David S. Miller" <davem@redhat.com>
To: Raja R Harinath <harinath@cs.umn.edu>
Cc: linux-kernel@vger.kernel.org
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On Mon, 2003-03-24 at 14:28, Raja R Harinath wrote:
> Something like
> 
>   /* struct user_space should never be defined.  */
>   typedef struct user_space user_space;
> 
>   int copy_to_user (user_space *to, char *from, size_t len);
>   int copy_from_user (char *to, user_space *from, size_t len);
>   /* ... */
> 
>   #define TREAT_AS_USER_SPACE_POINTER(p) \
>             ({                                  \
>               BUG_ON(get_fs() != get_gs());     \
>               (user_space *)p;                  \
>             })

A great idea, we'd need to use this struct user_space at every
system call, and it doesn't work to well when pointers are
embedded inside of a structure.

This is why a GCC attribute of some sort would be more useful.
But I don't see the GCC folks offering a user-definable attribute
+ checking system any time soon.

-- 
David S. Miller <davem@redhat.com>
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