[ros-kernel] MmMapLockedPages patch review

Hartmut Birr hartmut.birr at gmx.de
Sat Mar 6 23:02:02 CET 2004

> -----Original Message-----
> From: ros-kernel-bounces at reactos.com
> [mailto:ros-kernel-bounces at reactos.com] On Behalf Of Casper Hornstrup
> Sent: Saturday, March 06, 2004 10:08 PM
> To: 'ReactOS Kernel List'
> Subject: [ros-kernel] MmMapLockedPages patch review
> Hi all.
> I'm trying to implement the last case of MmMapLockedPages. Hartmut,
> David, other developers
> with knowledge of the memory manager, could you please comment on this
> patch? Will it do the
> job it is supposed to?
> Casper

I'm not sure but I think that the patch isn't correct. The parameter
AccessMode means, from where the pages must be accessible. For
AccessMode = UserMode, MmMapLockedPages must do the reverse part as for
KernelMode. This means, Mdl->MappedSystemVa should be a valid kernel
address and MmMapLockedPages must lock the pages and fill in
Mdl->StartVa with a user mode address from the current process. Some
parts of the mdl functions are a little bit dirty. They must be fixed
previously. The current implementation of the cache manager uses some
flags/values from a mdl in a wrong way.

- Hartmut

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