On Fri, 2019-06-07 at 12:03 -0700, Dave Hansen wrote: > On 6/6/19 1:09 PM, Yu-cheng Yu wrote: > > + modify_fpu_regs_begin(); > > + rdmsrl(MSR_IA32_U_CET, r); > > + r |= (MSR_IA32_CET_LEG_IW_EN | bitmap); > > + wrmsrl(MSR_IA32_U_CET, r); > > + modify_fpu_regs_end(); > > Isn't there a bunch of other stuff in this MSR? It seems like the > bitmap value would allow overwriting lots of bits in the MSR that have > nothing to do with the bitmap... in a prctl() that's supposed to only be > dealing with the bitmap. Yes, the bitmap address should have been masked, although it is checked for page alignment (which has the same effect). I will fix it. Yu-cheng
