From: 'Greg KH' > Sent: 02 November 2020 13:52 > > 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. Hopefully it won't appear again. Saved me spending a day off reading arm64 assembler. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
