On 2017-May-5, at 12:45 AM, Mark Millard <markmi at dsl-only.net> wrote:
> On 2017-May-4, at 2:41 PM, Dimitry Andric <dim at FreeBSD.org> wrote: > >> . . . >> Thanks for the notice. I have merged the upstream fix into head in >> r317810, and I will MFC it after a few days. > > I now have an old PowerMac running: > > # uname -paKU > FreeBSD FBSDG4S 12.0-CURRENT FreeBSD 12.0-CURRENT r317820M powerpc powerpc > 1200030 1200030 > > where buildworld was via clang 4 (an amd64->powerpc > cross build). Even the classic tiny program that > previously showed C++ exception handling was broken > and would crash the program now works when > re-compiled and re-linked. Commands that were > previous broken now work. > > (But my testing is nearly minimal at this point.) > > The kernel is from gcc421. > > > > I did try booting a kernel built by system-clang 4 > and it got to: > > exec /sbin/init: error 13 > > and a later alignment exception at sf_buf_alloc+0x260 > > (Hand transcribed screen information.) > > This is the same as the last time that I tried > such. The exception involved: > > exec_map_first_page > kern_execve > sys_execve > start_init > fork_exit > fork_trampoline > > > > For the gcc 4.2.1 based kernel boot I have > had one odd fatal kernel trap (0x903a64a, > "unknown") where the lr showed 0x907f . It > reported being stopped at: > > ffs_truncate+0x1080 > > It appears that "call doadump" worked but > I've not looked at what was put in > /var/crash/ . If I leave the PowerMac idle running: # uname -paKU FreeBSD FBSDG4S 12.0-CURRENT FreeBSD 12.0-CURRENT r317820M powerpc powerpc 1200030 1200030 it eventually gets the same ffs_truncate-tied fatal kernel trap, with the same odd lr and the like. So, while I cannot directly cause the problem at a specific time, the problem is repeatable. I did not build the kernel with a so-called "red-zone" to work around any stack-operation ordering problems that might still be around. But I do not know that such is involved here. It may be a while before I manage to get that much of an analysis done. === Mark Millard markmi at dsl-only.net _______________________________________________ freebsd-toolchain@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-toolchain To unsubscribe, send any mail to "freebsd-toolchain-unsubscr...@freebsd.org"
