On Fri, 2014-04-25 at 22:18 +1000, Anton Blanchard wrote: > Hi, > > > When trying offline cpus, I noticed following Oops in > > rtas_stop_self(), and it seems caused by commit 41dd03a9. The Oops > > disappears after reverting this commit. > > > > After reading the code, I guess it might be caused by moving the > > rtas_args to stack. Still need some more time to read enter_rtas to > > understand why it happens, but the problem seems could be solved by > > moving the rtas_args away from stack by adding static before it. > > Nice catch. RTAS is 32bit and if your box has more than 4GB RAM then > your stack could easily be outside 32bit range.
Ah, yes, the stack here is obviously at a much higher address than 4GB. > > You can add: > > Signed-off-by: Anton Blanchard <an...@samba.org> > > And also: > > Cc: sta...@vger.kernel.org # 3.14+ OK, Thanks, Zhong > > > Signed-off-by: Li Zhong <zh...@linux.vnet.ibm.com> > > --- > > arch/powerpc/platforms/pseries/hotplug-cpu.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c > > b/arch/powerpc/platforms/pseries/hotplug-cpu.c index 9b8e050..20d6297 > > 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c > > +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c > > @@ -88,13 +88,14 @@ void set_default_offline_state(int cpu) > > > > static void rtas_stop_self(void) > > { > > - struct rtas_args args = { > > - .token = cpu_to_be32(rtas_stop_self_token), > > + static struct rtas_args args = { > > .nargs = 0, > > .nret = 1, > > .rets = &args.args[0], > > }; > > > > + args.token = cpu_to_be32(rtas_stop_self_token); > > + > > local_irq_disable(); > > > > BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE); > > > > > > _______________________________________________ > > Linuxppc-dev mailing list > > Linuxppc-dev@lists.ozlabs.org > > https://lists.ozlabs.org/listinfo/linuxppc-dev > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev