Re: put_user and wp on i386

Pavel Machek (pavel@suse.cz)
Tue, 4 Jan 2000 21:54:35 +0100


Hi!

> The i386 version of the put_user(x, ptr) macro doesn't do
> wp_works_ok- checking. Also many drivers call put_user() without
> calling verify_area() before. Doesn't this lead to corruption with
> cow pages on a real i386 (wp doesn't work) ?

There are known races with real i386 and newer kernels, and same with
clone(). If it is easily fixable, it should be fixed...

Pavel
PS: There's way to crash cpu from userspace on real i386 :-(.

-- 
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents me at discuss@linmodems.org

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