Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!newstop!sun!amdcad!mozart.amd.com!proton!tim
From: tim@proton.amd.com (Tim Olson)
Newsgroups: comp.os.minix
Subject: Re: mem_copy problem in MM
Message-ID: <1990Jun6.154424.29594@mozart.amd.com>
Date: 6 Jun 90 15:44:24 GMT
References: <21184@nigel.udel.EDU>
Sender: usenet@mozart.amd.com (Usenet News)
Reply-To: tim@amd.com (Tim Olson)
Organization: Advanced Micro Devices, Inc., Austin, Texas
Lines: 21

In article <21184@nigel.udel.EDU> HBO043%DJUKFA11.BITNET@cunyvm.cuny.edu (Christoph van Wuellen) writes:
| The user program gives an address in his own address space, this must
| be converted to the flat space before using the address.
| On the ST, this might go since all processes share the same address space
| in reality, but you must not write code like that!
| 
| Second: I don't know if MM is allowed to copy something outside its own address
| space (or if it uses the SYSTASK to perform such actions).

Both of these points are correct -- however, the person asking the
question was using the mem_copy function, (in mm/utility.c), which
does send a message to the kernel to perform the operation, and the
kernel code does perform the virtual -> physical translation (via
umap()) before performing the physical copy.

I think the real problem lies in correctly adding this new system call
to mm's table.

	-- Tim Olson
	Advanced Micro Devices
	(tim@amd.com)