From ca4ad75e8f2058d965465d612ee1b5dcd364200e Mon Sep 17 00:00:00 2001 From: Lukas Larsson Date: Thu, 11 Aug 2016 10:35:24 +0200 Subject: erts: Align ErtsThrPrgrLaterOp when free'ing tracer On Sparc all structs with a double word element in are assumed to be allocated on a two word boundary. So we have to make sure that the ErtsThrPrgrLaterOp * points to 8 / 16 byte aligned memory. As it only costs one word I've done it on all architectures in case some unknown other arch also needs this. --- erts/emulator/beam/erl_trace.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) (limited to 'erts/emulator/beam/erl_trace.c') diff --git a/erts/emulator/beam/erl_trace.c b/erts/emulator/beam/erl_trace.c index d14d237ca6..c4396488f5 100644 --- a/erts/emulator/beam/erl_trace.c +++ b/erts/emulator/beam/erl_trace.c @@ -3108,6 +3108,7 @@ erts_tracer_update(ErtsTracer *tracer, const ErtsTracer new_tracer) if (is_not_nil(*tracer)) { Uint offs = 2; UWord size = 2 * sizeof(Eterm) + sizeof(ErtsThrPrgrLaterOp); + ErtsThrPrgrLaterOp *lop; ASSERT(is_list(*tracer)); if (is_not_immed(ERTS_TRACER_STATE(*tracer))) { hf = (void*)(((char*)(ptr_val(*tracer)) - offsetof(ErlHeapFragment, mem))); @@ -3115,6 +3116,16 @@ erts_tracer_update(ErtsTracer *tracer, const ErtsTracer new_tracer) size = hf->alloc_size * sizeof(Eterm) + sizeof(ErlHeapFragment); ASSERT(offs == size_object(*tracer)); } + + /* sparc assumes that all structs are double word aligned, so we + have to align the ErtsThrPrgrLaterOp struct otherwise it may + segfault.*/ + if ((UWord)(ptr_val(*tracer) + offs) % (sizeof(UWord)*2) == sizeof(UWord)) + offs += 1; + + lop = (ErtsThrPrgrLaterOp*)(ptr_val(*tracer) + offs); + ASSERT((UWord)lop % (sizeof(UWord)*2) == 0); + /* We schedule the free:ing of the tracer until after a thread progress has been made so that we know that no schedulers have any references to it. Because we do this, it is possible to release all locks of a @@ -3122,9 +3133,7 @@ erts_tracer_update(ErtsTracer *tracer, const ErtsTracer new_tracer) without having to worry if it is free'd. */ erts_schedule_thr_prgr_later_cleanup_op( - free_tracer, (void*)(*tracer), - (ErtsThrPrgrLaterOp*)(ptr_val(*tracer) + offs), - size); + free_tracer, (void*)(*tracer), lop, size); } if (is_nil(new_tracer)) { @@ -3141,9 +3150,10 @@ erts_tracer_update(ErtsTracer *tracer, const ErtsTracer new_tracer) Eterm *hp, tracer_state = ERTS_TRACER_STATE(new_tracer), tracer_module = ERTS_TRACER_MODULE(new_tracer); Uint sz = size_object(tracer_state); - hf = new_message_buffer(sz + 2 /* cons cell */ + (sizeof(ErtsThrPrgrLaterOp)+sizeof(Eterm)-1)/sizeof(Eterm)); + hf = new_message_buffer(sz + 2 /* cons cell */ + + (sizeof(ErtsThrPrgrLaterOp)+sizeof(Eterm)-1)/sizeof(Eterm) + 1); hp = hf->mem + 2; - hf->used_size -= (sizeof(ErtsThrPrgrLaterOp)+sizeof(Eterm)-1)/sizeof(Eterm); + hf->used_size -= (sizeof(ErtsThrPrgrLaterOp)+sizeof(Eterm)-1)/sizeof(Eterm) + 1; *tracer = copy_struct(tracer_state, sz, &hp, &hf->off_heap); *tracer = CONS(hf->mem, tracer_module, *tracer); ASSERT((void*)(((char*)(ptr_val(*tracer)) - offsetof(ErlHeapFragment, mem))) == hf); -- cgit v1.2.3