Re: [PATCH] kill access_ok() call from copy_siginfo_to_user() thatwe might as well avoid.

From: Linus Torvalds
Date: Mon Dec 20 2004 - 19:19:21 EST

On Tue, 21 Dec 2004, Jesper Juhl wrote:
> In kernel/signal.c::copy_siginfo_to_user() we are calling access_ok()
> unconditionally. As I see it there's no need for this since we might as
> well just call copy_to_user() instead of __copy_to_user() later on and
> then only get the overhead of the access_ok() check (inside
> copy_to_user())

No, the "access_ok()" is to protect the other side too, ie all the
"__put_user()" calls.

If you remove the access_ok(), you need to also change all the
__put_user() calls to "put_user()". And then the end result will be much
worse code than it is right now.

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