From: paul.winalski@gmail.com (Paul Winalski)
Subject: [TUHS] Harvard and Von Neumann Architectures and Unix
Date: Tue, 28 Nov 2017 14:45:19 -0500 [thread overview]
Message-ID: <CABH=_VSx781Bt0_8ZfhKNfd+v5J_2ZuyK=0Awm0yfc7D+KpQbg@mail.gmail.com> (raw)
In-Reply-To: <2E06126D-C247-4D2B-97A2-DE0A449594E4@tfeb.org>
On 27 Nov 2017, at 16:11, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
>
> Along those lines, I was wondering about modern OS's, which I gather for
> security reasons prevent execution of data, and prevent writing to code.
They do by default, at least, in that modern linkers create executable
images where the executable program segments are read-only and
read/write segments (including the stack) are not executable. But
modern OSes have system services for changing page protection, so an
application such as an interpreter or JIT can compose code and then
change the page protection to make it executable.
-Paul W.
next prev parent reply other threads:[~2017-11-28 19:45 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-27 16:11 Noel Chiappa
2017-11-27 16:50 ` Larry McVoy
2017-11-27 17:08 ` Clem Cole
2017-11-27 18:21 ` Lawrence Stewart
2017-11-27 18:30 ` Lars Brinkhoff
2017-11-27 18:14 ` Warner Losh
2017-11-27 18:26 ` Paul Winalski
2017-11-27 17:35 ` Ian Zimmerman
2017-11-28 14:55 ` Tim Bradshaw
2017-11-28 19:45 ` Paul Winalski [this message]
-- strict thread matches above, loose matches on Subject: below --
2017-11-27 17:11 Noel Chiappa
2017-11-28 0:23 ` Dave Horsfall
2017-11-25 17:34 Doug McIlroy
2017-11-25 14:24 Noel Chiappa
2017-11-25 15:58 ` Lawrence Stewart
2017-11-25 16:10 ` Lars Brinkhoff
2017-11-25 19:59 ` Steve Simon
2017-11-25 21:59 ` Bakul Shah
2017-11-25 3:14 Doug McIlroy
2017-11-25 4:16 ` Jon Steinhart
2017-11-25 5:17 ` ron minnich
2017-11-25 14:23 ` Ralph Corderoy
2017-11-24 21:43 Noel Chiappa
2017-11-24 21:50 ` Jon Steinhart
2017-11-25 21:55 ` William Cheswick
2017-11-25 23:15 ` Dave Horsfall
2017-11-24 22:20 ` Mike Markowski
2017-11-24 22:31 ` Dave Horsfall
2017-11-24 19:25 Will Senn
2017-11-24 19:28 ` Jon Steinhart
2017-11-27 14:50 ` Tony Finch
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