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Date: Sat, 14 Jun 2008 19:44:12 +0200
From: Ed Schouten <ed@80386.nl>
To: amd64@freebsd.org
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Subject: VM_PROT_EXEC on the stack
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Hello everyone,

I'm not a real guru when it comes to low level x86 hardware stuff, but
some time ago I read somewhere that the NX bit on AMD64 CPU's could be
used to mark the stack as non-executable, making it impossible to
execute code on the stack (through buffer overflows).

When I look at procstat -v's output on FreeBSD/amd64, I see the stack
has VM_PROT_EXEC. Is there a specific reason for this?

Yours,
--=20
 Ed Schouten <ed@80386.nl>
 WWW: http://80386.nl/

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