diff options
Diffstat (limited to 'erts/emulator')
| -rw-r--r-- | erts/emulator/beam/erl_gc.c | 45 |
1 files changed, 42 insertions, 3 deletions
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c index 67a73e4d57..7ab8034606 100644 --- a/erts/emulator/beam/erl_gc.c +++ b/erts/emulator/beam/erl_gc.c @@ -151,6 +151,7 @@ static void grow_new_heap(Process *p, Uint new_sz, Eterm* objv, int nobj); static void sweep_off_heap(Process *p, int fullsweep); static void offset_heap(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size); static void offset_heap_ptr(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size); +static void offset_heap_ptr_nstack(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size); static void offset_rootset(Process *p, Sint offs, char* area, Uint area_size, Eterm* objv, int nobj); static void offset_off_heap(Process* p, Sint offs, char* area, Uint area_size); @@ -1054,9 +1055,10 @@ erts_garbage_collect_hibernate(Process* p) n_htop = tmp_n_htop; \ } while(0) + /* * offset_nstack() can ignore the descriptor-based traversal the other - * nstack procedures use and simply call offset_heap_ptr() instead. + * nstack procedures use and do a simpler word by word traversal instead. * This relies on two facts: * 1. The only live non-Erlang terms on an nstack are return addresses, * and they will be skipped thanks to the low/high range check. @@ -1071,14 +1073,51 @@ static ERTS_INLINE void offset_nstack(Process* p, Sint offs, { if (p->hipe.nstack) { ASSERT(p->hipe.nsp && p->hipe.nstend); - offset_heap_ptr(hipe_nstack_start(p), hipe_nstack_used(p), - offs, area, area_size); + offset_heap_ptr_nstack(hipe_nstack_start(p), hipe_nstack_used(p), + offs, area, area_size); } else { ASSERT(!p->hipe.nsp && !p->hipe.nstend); } } +/* + * This is the same as offset_heap_ptr() + * + * Except for VALGRIND. It allows benign offsetting of undefined (dead) words + * on the nstack while also retaining them as undefined. This suppresses + * valgrinds "Conditional jump or move depends on uninitialised value(s)". + */ +static void +offset_heap_ptr_nstack(Eterm* hp, Uint sz, Sint offs, + char* area, Uint area_size) +{ + while (sz--) { + Eterm val = *hp; +#ifdef VALGRIND + Eterm val_vbits; + VALGRIND_GET_VBITS(&val, &val_vbits, sizeof(val)); + VALGRIND_MAKE_MEM_DEFINED(&val, sizeof(val)); +#endif + switch (primary_tag(val)) { + case TAG_PRIMARY_LIST: + case TAG_PRIMARY_BOXED: + if (ErtsInArea(ptr_val(val), area, area_size)) { +#ifdef VALGRIND + VALGRIND_SET_VBITS(&val, val_vbits, sizeof(val)); +#endif + *hp = offset_ptr(val, offs); + } + hp++; + break; + default: + hp++; + break; + } + } +} + + #else /* !HIPE */ #define fullsweep_nstack(p,n_htop) (n_htop) |