Richard Henderson <r...@twiddle.net> writes: > On 11/30/2016 08:55 AM, Alex Bennée wrote: >> >> Nikunj A Dadhania <nik...@linux.vnet.ibm.com> writes: >> >>> Hi, >>> >>> I was writing one instruction and hit following issue: >>> >>> [snip]/qemu/tcg/tcg.c:2039: tcg fatal error >>> qemu-ppc64le: [snip]/qemu/translate-all.c:175: tb_lock: Assertion >>> `!have_tb_lock' failed. >>> Segmentation fault (core dumped) >> >> This is confusing because something is trying to take the tb_lock while >> you are in code generation. tb_lock is held for code generation to >> ensure serialisation of generation. > > Yes, I've seen this myself. I never got around to reporting the "problem" > properly. It's a confusing side effect of a SIGSEGV arriving during tcg code > generation. The signal handler longjmps back with unexpected locks > held.
So this is a SEGV which belongs to the translation code rather than the guest? There are places in the cpu loop where we exit that should reset the locks on a restart - see tb_lock_reset() so I'm not quite sure what has happened here. > > Probably we should simply crash earlier and less confusingly. > > > r~ -- Alex Bennée
