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From: Alexander Monakov <amonakov@ispras.ru>
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Subject: Re: Documentation of memcpy and undefined behavior in
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Date: Thu, 6 Jul 2017 20:17:32 +0300 (MSK)
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On Thu, 6 Jul 2017, Rich Felker wrote:

> If p points to one past the end of an object that ends on a page
> boundary, this transformation could introduce a crash.

The object beginning at p (i.e. the array beginning just after the
array which p was derived from) could be volatile, making that an
invalid transformation. Nothing gives the compiler a guarantee
that that area is non-volatile.

Alexander