And it was only that latter operation that I pointed at.The latter load however can easy fault; The arguments for %ds inOn 09.04.14 at 16:41, <andrew.cooper3@xxxxxxxxxx> wrote:
XSA-42/ CVE-2013-0228 applies to %{e,f,g}s as well.
Furthermore, I am a little concerned about the performance impact ofWhy would you expect %fs on the IRET path to commonly point to the
this. I would have thought that in most cases, %fs will already be
correct, at which point reloading it twice is a waste of time.
kernel segment rather than whatever user mode wants/needs? Also, I'm
not sure adding conditionals here wouldn't harm performance about as
much as the save/load/restore. If anything I'd look into open coding
GET_THREAD_INFO() without using %fs for this single case.
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel