> From: Hansen, Dave > Sent: Monday, March 02, 2015 4:00 PM > > Hi Fenghua, > > I was testing some new MPX code, and realized that MPX had stopped > working completely. The prctl() failed to turn it on, which I tracked down > to a > 0 in "BNDCSR" where we expected to see an enable bit. > > I realized that I had managed to remove the "noxsaves" boot option from my > kernel. Re-adding "noxsaves" made MPX work again, and the BNDCSR > contents were properly passed in to the kernel. > > Is it possible that "xsaves" use inside the kernel is simply broken? > > Config is here: > > http://sr71.net/~dave/intel/config-20150302
Xsaves has been tested by QA since 3.17 with or without MPX. I'm not aware of reported issues. But MPX is the only code to call the get_xsave_addr kernel API. Though it has been tested before on upstream MPX code. What changes in your new MPX code? Thanks. -Fenghua
