On Tue 2017-09-05 14:44:56, David Miller wrote:

From: Pavel Machek <redacted>
Date: Mon, 4 Sep 2017 18:25:30 +0200

quoted

Will gcc be able to compile code that uses these automatically? That
does not sound easy to me. Can libc automatically use this in malloc()
to prevent accessing freed data when buffers are overrun?

Is this for benefit of JITs?

Anything that can control mappings and the virtual address used to
access memory can use ADI.

malloc() is of course one such case.  It can map memory with ADI
enabled, and return buffer addresses to malloc() callers with the
proper virtual address bits set to satisfy the ADI key checks.

And by induction anything using malloc() for it's memory allocation
gets ADI protection as well.

I see; that's actually quite a nice trick.

I guess it does not protect against stack-based overflows, but should
help against heap-based overflows, so it improves security a bit, too.

Nice, thanks for explanation.
									Pavel
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