On Fri, 28 Sep 2018, Thomas Gleixner wrote: > On Thu, 27 Sep 2018, Andy Lutomirski wrote: > > I have a couple questions here: > > > > - Is this actually okay on all architectures? That is, are there > > cases where we'll screw up if we fail a USER_DS access this early? > > s390 stands out as the obvious special case (where USER_DS is not > > than just a subset of KERNEL_DS), but s390 opts out. > > > > - Why doesn't x86 set HAVE_FUTEX_CMPXCHG? Or do we still support > > some 32-bit configurations that don't have cmpxchg and don't know > > about it at compile time? > > I'm not entirely sure. Have to dig into the details. I assume S390 just can > set it though. x86 as well. It's supported from 486 onwards and we ripped out 386 years ago. Thanks, tglx
