Re: VERIFY_READ/WRITE in uaccess.h?

From: H. Peter Anvin
Date: Tue May 12 2015 - 01:47:42 EST


On 05/11/2015 02:42 PM, Linus Torvalds wrote:
>
> That one - for the same reasons - also checked the actual accesses,
> not just that the range was in user mode. Exactly because it needed to
> pre-COW the pages (even if that was then obviously racy in threaded
> environments - in practice it worked, and we tried to support the
> fundamentally broken i386 hardware protection model for a long time).
>

It worked in part because we never supported SMP on i386.

-hpa


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