On Fri, Nov 15, 2019 at 1:31 PM Paul Durrant <pdurr...@gmail.com> wrote:
> On Thu, 14 Nov 2019 at 04:57, Julian Tuminaro <julian.tumin...@gmail.com> > wrote: > > > > From: Julian Tuminaro and Jenish Rakholiya <julian.tumin...@gmail.com > and rakholiyajenish...@gmail.com> > > > > Current implementation of find_os is based on the hard-coded values for > > different Windows version. It uses the value for get the address to > > start looking for DOS header in the given specified range. However, this > > is not scalable to all version of Windows as it will require us to keep > > adding new entries and also due to KASLR, chances of not hitting the PE > > header is significant. We implement a way for 64-bit systems to use IDT > > entry to get a valid exception/interrupt handler and then move back into > > the memory to find the valid DOS header. Since IDT entries are protected > > by PatchGuard, we think our assumption that IDT entries will not be > > corrupted is valid for our purpose. Once we have the image base, we > > search for the DBGKD_GET_VERSION64 structure type in .data section to > > get information required for handshake. > > > > Currently, this is a work in progress feature and current patch only > > supports the handshake and memory read/write on 64-bit systems. > > > > NOTE: This is the Updated version of the previous patch submitted > > NOTE: This has currently been only tested when debugging was not enabled > > on the guest Windows. > > > > Signed-off-by: Jenish Rakholiya <rjen...@cmu.edu> > > Signed-off-by: Julian Tuminaro <jtumi...@andrew.cmu.edu> > > LGTM. > > Reviewed-by: Paul Durrant <p...@xen.org> > Paul, is this something worth adding a line to CHANGELOG about? -George
