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From: donn@utah-gr.UUCP (Donn Seeley)
Newsgroups: net.unix-wizards
Subject: Re: /dev/kUmem and other memory questions
Message-ID: <1461@utah-gr.UUCP>
Date: Sat, 25-May-85 23:43:01 EDT
Article-I.D.: utah-gr.1461
Posted: Sat May 25 23:43:01 1985
Date-Received: Mon, 27-May-85 07:24:32 EDT
References: <437@cadre.ARPA> <5@ucbcad.UUCP> <6007@umcp-cs.UUCP>
Organization: University of Utah CS Dept
Lines: 19

Let us not overlook the notorious ptrace() system call...  This is used
by debuggers to do gross things like modify the text of a process to
insert breakpoints, and to read and write a process's 'u' area.  Using
ptrace() is not very convenient -- there are several restrictions on
which processes you may access, what the victim process must do in
order to allow you to perform surgery on it, what you can change in the
victim process and how much data you can change at each transaction (32
bits, on a VAX).  ptrace() does not require dubious sorts of diddling
in /dev/mem or /dev/swap (aka /dev/drum), however.

On Eighth Edition systems there is a directory named '/proc' which you
can use to access a process's address space as though it were a file.
Someday this feature will make its way into systems which people other
than Peter Honeyman can buy...

Donn Seeley    University of Utah CS Dept    donn@utah-cs.arpa
40 46' 6"N 111 50' 34"W    (801) 581-5668    decvax!utah-cs!donn

PS -- Shouldn't this sort of stuff go in net.unix?