Re: [Crash-utility] [PATCH 0/7] Upgrade the remote access to a xen domain.

On Tue, Nov 19, 2013 at 06:46:39AM -0500, Don Slutz wrote: > From: Don Slutz <dslutz(a)verizon.com&gt; > > Currently crash 4.0 and later using the code: > > http://lists.xen.org/archives/html/xen-devel/2013-11/msg02569.html > > There is some very limited documention on crashes remote ptotocol in: > > http://lists.xen.org/archives/html/xen-devel/2013-11/msg02352.html > > and some fixes in the attachment 0001-xen-crashd-Connect-crash-with-domain.patch > from the 1st link above. > > How ever there are issues with the current code: > > 1) The remote protocol has a minor issue (which I have not been able to > happen) based on the fact TCP/IP is stream based protocol. This means > a RECV or a SEND may not do the fully requested size of data. In fact > the current code assumes that the amount of data that a SEND is called > with will all be read with a single RECV. > > 2) The most common mismatch between crash and older kernels is > phys_base. In the remote case, see if the remote server supports > vitrual memory access, and if so, see if phys_base can be retreived. > > 3) crash assumes that the remote system is active and can not return > currect IP and SP to do a better back trace. > > 4) enable a non-active mode of remote access. > > This patch set attempts to fix these: > > The fix for #1 I have called NIL mode (patch 1). > The fix for #2 uses get_remote_phys_base (patch 3). > The fix for #3 uses get_remote_regs (patch 5). > The fix for #4 uses special file /dev/xenmem (patch 7). Where is this file created? In guest or in host. Is it done by udev? Where is driver for this file?

> It also REMOTE_NIL() to indicate "remote paused system". > > Don Slutz (7): > Add NIL mode to remote. > remote_proc_version: NULL terminate passed buffer on error. > Add get_remote_phys_base. > Add remote_vtop. > bt: get remote live registers if possible. > Add get_remote_cr3 > Add support for non-live remote. > > defs.h | 8 +- > kernel.c | 25 +++- > memory.c | 25 +++- > remote.c | 462 +++++++++++++++++++++++++++++++++++++++++++++++++++++---------- > x86_64.c | 24 ++++ > 5 files changed, 465 insertions(+), 79 deletions(-) I have done quick review. It looks quite nice. There are two nitpicks for me. Please do not use camelCase (I have found one in patch 3 in struct _remote_context) and do not add Emacs directives at the end of files (this is Xen specific stuff).

Daniel