Christos Zoulas writes: > In article <20190106003905.60969f...@cvs.netbsd.org>, > Rin Okuyama <source-changes-d@NetBSD.org> wrote: > >-=-=-=-=-=- > > > >Module Name: src > >Committed By: rin > >Date: Sun Jan 6 00:39:05 UTC 2019 > > > >Modified Files: > > src/sys/dev/usb: if_axe.c > > > >Log Message: > >Fix kernel panic on arm reported by @furandon_pig on Twitter. > > > >Hardware header is 2-byte aligned in RX buffer, not 4-byte. > >For some architectures, __builtin_memcpy() of GCC 6 attempts to > >copy 4-byte header at once, which results in alignment error. > > This is really ugly.. > > https://stackoverflow.com/questions/24883410/armcc-problems-with-memcpy-alignment-exceptions > > Perhaps there is a better solution? Can't memcpy be smarter?
hmmm, what happens if struct axe_sframe_hdr is not marked "packed"? this feels like a compiler bug, but perhaps it is assuming it can write 4 bytes to the structure when it is only 2 byte aligned. is there a small test case that reproduces the problem? preferably in user land? .mrg.
