Hi Anton, On Sat, Jun 03, 2017 at 08:04:11AM +1000, Anton Blanchard wrote: > Hi Breno, > > > Currently tsk->thread->load_vec and load_fp are not initialized > > during a task creation, which set garbage to these variables > > (non-zero value). > > Nice catch! It seems like we should zero load_tm too though?
Yes, it seems we need to zero load_tm also, since it does not seem to be zeroed anywhere else. But I did some tests, and load_tm is always zero after start_thread() is being called. In fact, start_thread() is being called and pt_regs->load_tm is already zero since the function start. I also wrote a SystemTap script[1] to investigate it better, and I've never seen a single load_tm != 0 in a my machine. I tested on both POWER8 bare metal and KVM guests. (load_vec and load_fp happened to have garbage all the time) Any idea if this is just occasional event, or, if there is someone zeroing it in an obscure code? [1] https://github.com/leitao/htm_torture/blob/master/systemtap/load_tm_at_start_thread.stap
