On Sun, Jun 25, 2017 at 10:53:58AM +0100, Al Viro wrote: > On Sat, Jun 24, 2017 at 12:29:23PM -0500, Larry Finger wrote: > > > I made a break through. If I turn off inline copy to/from users for 32-bit > > ppc with the following patch, then the system boots: > > OK... So it's 4.6.3 miscompiling something - it is hardware-independent, > reproduced in qemu. I'd like to get more self-contained example of > miscompile, though; should be done by tonight...
OK, it's the call in rw_copy_check_uvector(); with INLINE_COPY_FROM_USER it's miscompiled by 4.6.3. I hadn't looked through the generated code yet; will do that after I grab some sleep.