On Mon, Nov 02, 2020 at 09:06:38AM +0000, David Laight wrote: > From: 'Greg KH' > > Sent: 23 October 2020 15:47 > > > > On Fri, Oct 23, 2020 at 02:39:24PM +0000, David Laight wrote: > > > From: David Hildenbrand > > > > Sent: 23 October 2020 15:33 > > > ... > > > > I just checked against upstream code generated by clang 10 and it > > > > properly discards the upper 32bit via a mov w23 w2. > > > > > > > > So at least clang 10 indeed properly assumes we could have garbage and > > > > masks it off. > > > > > > > > Maybe the issue is somewhere else, unrelated to nr_pages ... or clang 11 > > > > behaves differently. > > > > > > We'll need the disassembly from a failing kernel image. > > > It isn't that big to hand annotate. > > > > I've worked around the merge at the moment in the android tree, but it > > is still quite reproducable, and will try to get a .o file to > > disassemble on Monday or so... > > Did this get properly resolved? For some reason, 5.10-rc2 fixed all of this up. I backed out all of the patches I had to revert to get 5.10-rc1 to work properly, and then did the merge and all is well. It must have been something to do with the compat changes in this same area that went in after 5.10-rc1, and something got reorganized in the files somehow. I really do not know, and at the moment, don't have the time to track it down anymore. So for now, I'd say it's all good, sorry for the noise. greg k-h