From f0131c58c42a286c8b3f611b47106393a37197b6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Magnus=20L=C3=A5ng?= Date: Mon, 23 May 2016 15:41:31 +0200 Subject: check_process_code: Sweep HiPE stack for literals Because check_process_code neglected checking the HiPE stack for references to the literal area, such references would survive the purge and subsequent deletion of a module and its literal area. These dangling references would then cause incorrect behaviour or even hard crashes of the VM. By simply adding a scan of the HiPE stack to check_process_code and erts_garbage_collect_literals, this problem is fixed. In order to support full stack walks without deleting the graylimit trap, a new stack walking interface function, nstack_walk_init_sdesc_ignore_trap() was introduced. --- erts/emulator/beam/beam_bif_load.c | 8 ++ erts/emulator/beam/erl_gc.c | 104 +++++++++++---------- erts/emulator/hipe/hipe_gc.c | 119 ++++++++++++++++++++++++ erts/emulator/hipe/hipe_risc_gc.h | 13 +++ erts/emulator/hipe/hipe_stack.h | 3 + erts/emulator/hipe/hipe_x86_gc.h | 17 ++++ erts/emulator/test/Makefile | 1 + erts/emulator/test/hipe_SUITE.erl | 64 +++++++++++++ erts/emulator/test/hipe_SUITE_data/literals.erl | 26 ++++++ erts/emulator/test/hipe_SUITE_data/ref_cell.erl | 64 +++++++++++++ 10 files changed, 368 insertions(+), 51 deletions(-) create mode 100644 erts/emulator/test/hipe_SUITE.erl create mode 100644 erts/emulator/test/hipe_SUITE_data/literals.erl create mode 100644 erts/emulator/test/hipe_SUITE_data/ref_cell.erl (limited to 'erts/emulator') diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c index 15e878ba65..92815b2bcd 100644 --- a/erts/emulator/beam/beam_bif_load.c +++ b/erts/emulator/beam/beam_bif_load.c @@ -37,6 +37,10 @@ #include "erl_bits.h" #include "erl_thr_progress.h" +#ifdef HIPE +# include "hipe_stack.h" +#endif + static void set_default_trace_pattern(Eterm module); static Eterm check_process_code(Process* rp, Module* modp, Uint flags, int *redsp, int fcalls); static void delete_code(Module* modp); @@ -916,6 +920,10 @@ check_process_code(Process* rp, Module* modp, Uint flags, int *redsp, int fcalls } if (any_heap_ref_ptrs(rp->stop, rp->hend, literals, lit_bsize)) goto try_literal_gc; +#ifdef HIPE + if (nstack_any_heap_ref_ptrs(rp, literals, lit_bsize)) + goto try_literal_gc; +#endif if (any_heap_refs(rp->heap, rp->htop, literals, lit_bsize)) goto try_literal_gc; if (any_heap_refs(rp->old_heap, rp->old_htop, literals, lit_bsize)) diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c index d0d74bbf44..29646719d0 100644 --- a/erts/emulator/beam/erl_gc.c +++ b/erts/emulator/beam/erl_gc.c @@ -882,6 +882,58 @@ erts_garbage_collect_hibernate(Process* p) } +/* + * HiPE native code stack scanning procedures: + * - fullsweep_nstack() + * - gensweep_nstack() + * - offset_nstack() + * - sweep_literals_nstack() + */ +#if defined(HIPE) + +#define GENSWEEP_NSTACK(p,old_htop,n_htop) \ + do { \ + Eterm *tmp_old_htop = old_htop; \ + Eterm *tmp_n_htop = n_htop; \ + gensweep_nstack((p), &tmp_old_htop, &tmp_n_htop); \ + old_htop = tmp_old_htop; \ + 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. + * 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. + * 2. Dead values, even if mistaken for pointers into the low/high area, + * can be offset safely since they won't be dereferenced. + * + * XXX: WARNING: If HiPE starts storing other non-Erlang values on the + * nstack, such as floats, then this will have to be changed. + */ +static ERTS_INLINE void offset_nstack(Process* p, Sint offs, + char* area, Uint area_size) +{ + 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); + } + else { + ASSERT(!p->hipe.nsp && !p->hipe.nstend); + } +} + +#else /* !HIPE */ + +#define fullsweep_nstack(p,n_htop) (n_htop) +#define GENSWEEP_NSTACK(p,old_htop,n_htop) do{}while(0) +#define offset_nstack(p,offs,area,area_size) do{}while(0) +#define sweep_literals_nstack(p,old_htop,area,area_size) (old_htop) + +#endif /* HIPE */ + void erts_garbage_collect_literals(Process* p, Eterm* literals, Uint byte_lit_size, @@ -944,7 +996,7 @@ erts_garbage_collect_literals(Process* p, Eterm* literals, area_size = byte_lit_size; n = setup_rootset(p, p->arg_reg, p->arity, &rootset); roots = rootset.roots; - old_htop = p->old_htop; + old_htop = sweep_literals_nstack(p, p->old_htop, area, area_size); while (n--) { Eterm* g_ptr = roots->v; Uint g_sz = roots->sz; @@ -1211,56 +1263,6 @@ minor_collection(Process* p, ErlHeapFragment *live_hf_end, return -1; } -/* - * HiPE native code stack scanning procedures: - * - fullsweep_nstack() - * - gensweep_nstack() - * - offset_nstack() - */ -#if defined(HIPE) - -#define GENSWEEP_NSTACK(p,old_htop,n_htop) \ - do { \ - Eterm *tmp_old_htop = old_htop; \ - Eterm *tmp_n_htop = n_htop; \ - gensweep_nstack((p), &tmp_old_htop, &tmp_n_htop); \ - old_htop = tmp_old_htop; \ - 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. - * 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. - * 2. Dead values, even if mistaken for pointers into the low/high area, - * can be offset safely since they won't be dereferenced. - * - * XXX: WARNING: If HiPE starts storing other non-Erlang values on the - * nstack, such as floats, then this will have to be changed. - */ -static ERTS_INLINE void offset_nstack(Process* p, Sint offs, - char* area, Uint area_size) -{ - 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); - } - else { - ASSERT(!p->hipe.nsp && !p->hipe.nstend); - } -} - -#else /* !HIPE */ - -#define fullsweep_nstack(p,n_htop) (n_htop) -#define GENSWEEP_NSTACK(p,old_htop,n_htop) do{}while(0) -#define offset_nstack(p,offs,area,area_size) do{}while(0) - -#endif /* HIPE */ - static void do_minor(Process *p, ErlHeapFragment *live_hf_end, char *mature, Uint mature_size, diff --git a/erts/emulator/hipe/hipe_gc.c b/erts/emulator/hipe/hipe_gc.c index 566c65882e..68c65dea27 100644 --- a/erts/emulator/hipe/hipe_gc.c +++ b/erts/emulator/hipe/hipe_gc.c @@ -237,3 +237,122 @@ void gensweep_nstack(Process *p, Eterm **ptr_old_htop, Eterm **ptr_n_htop) } abort(); } + +Eterm *sweep_literals_nstack(Process *p, Eterm *old_htop, char *area, + Uint area_size) +{ + /* known nstack walk state */ + Eterm *nsp; + Eterm *nsp_end; + const struct sdesc *sdesc; + /* arch-specific nstack walk state */ + struct nstack_walk_state walk_state; + + ASSERT(!p->hipe.gc_is_unsafe); + + if (!p->hipe.nstack) { + ASSERT(!p->hipe.nsp && !p->hipe.nstend); + return old_htop; + } + if (!nstack_walk_init_check(p)) + return old_htop; + + ASSERT(p->hipe.nsp && p->hipe.nstend); + nsp = nstack_walk_nsp_begin(p); + nsp_end = nstack_walk_nsp_end(p); + sdesc = nstack_walk_init_sdesc_ignore_trap(p, &walk_state); + + while (!nstack_walk_nsp_reached_end(nsp, nsp_end)) { + unsigned long ra; + unsigned sdesc_size = nstack_walk_frame_size(sdesc); + unsigned i = 0; + unsigned mask = sdesc->livebits[0]; + for (;;) { + if (mask & 1) { + Eterm *nsp_i = nstack_walk_frame_index(nsp, i); + Eterm gval = *nsp_i; + if (is_boxed(gval)) { + Eterm *ptr = boxed_val(gval); + Eterm val = *ptr; + if (IS_MOVED_BOXED(val)) { + ASSERT(is_boxed(val)); + *nsp_i = val; + } else if (ErtsInArea(ptr, area, area_size)) { + MOVE_BOXED(ptr, val, old_htop, nsp_i); + } + } else if (is_list(gval)) { + Eterm *ptr = list_val(gval); + Eterm val = *ptr; + if (IS_MOVED_CONS(val)) { + *nsp_i = ptr[1]; + } else if (ErtsInArea(ptr, area, area_size)) { + MOVE_CONS(ptr, val, old_htop, nsp_i); + } + } + } + if (++i >= sdesc_size) + break; + if (i & 31) + mask >>= 1; + else + mask = sdesc->livebits[i >> 5]; + } + ra = nstack_walk_frame_ra(nsp, sdesc); + if (ra == (unsigned long)nbif_stack_trap_ra) + ra = (unsigned long)p->hipe.ngra; + sdesc = hipe_find_sdesc(ra); + nsp = nstack_walk_next_frame(nsp, sdesc_size); + } + return old_htop; +} + +int +nstack_any_heap_ref_ptrs(Process *rp, char* mod_start, Uint mod_size) +{ + Eterm *nsp; + Eterm *nsp_end; + const struct sdesc *sdesc; + /* arch-specific nstack walk state */ + struct nstack_walk_state walk_state; + + ASSERT(!rp->hipe.gc_is_unsafe); + + if (!rp->hipe.nstack || !nstack_walk_init_check(rp)) return 0; + ASSERT(rp->hipe.nsp && rp->hipe.nstend); + nsp = nstack_walk_nsp_begin(rp); + nsp_end = nstack_walk_nsp_end(rp); + sdesc = nstack_walk_init_sdesc_ignore_trap(rp, &walk_state); + + while (!nstack_walk_nsp_reached_end(nsp, nsp_end)) { + unsigned long ra; + unsigned sdesc_size = nstack_walk_frame_size(sdesc); + unsigned i = 0; + unsigned mask = sdesc->livebits[0]; + for (;;) { + if (mask & 1) { + Eterm *nsp_i = nstack_walk_frame_index(nsp, i); + Eterm val = *nsp_i; + switch (primary_tag(val)) { + case TAG_PRIMARY_BOXED: + case TAG_PRIMARY_LIST: + if (ErtsInArea(val, mod_start, mod_size)) { + return 1; + } + break; + } + } + if (++i >= sdesc_size) + break; + if (i & 31) + mask >>= 1; + else + mask = sdesc->livebits[i >> 5]; + } + ra = nstack_walk_frame_ra(nsp, sdesc); + if (ra == (unsigned long)nbif_stack_trap_ra) + ra = (unsigned long)rp->hipe.ngra; + sdesc = hipe_find_sdesc(ra); + nsp = nstack_walk_next_frame(nsp, sdesc_size); + } + return 0; +} diff --git a/erts/emulator/hipe/hipe_risc_gc.h b/erts/emulator/hipe/hipe_risc_gc.h index 315f8e7f9f..09568c140e 100644 --- a/erts/emulator/hipe/hipe_risc_gc.h +++ b/erts/emulator/hipe/hipe_risc_gc.h @@ -51,6 +51,19 @@ nstack_walk_init_sdesc(const Process *p, struct nstack_walk_state *state) return sdesc; } +static inline const struct sdesc* +nstack_walk_init_sdesc_ignore_trap(const Process *p, + struct nstack_walk_state *state) +{ + unsigned long ra = (unsigned long)p->hipe.nra; + const struct sdesc *sdesc; + if (ra == (unsigned long)&nbif_stack_trap_ra) + ra = (unsigned long)p->hipe.ngra; + sdesc = hipe_find_sdesc(ra); + state->sdesc0 = sdesc; + return sdesc; +} + static inline void nstack_walk_update_trap(Process *p, const struct sdesc *sdesc0) { Eterm *nsp = p->hipe.nsp; diff --git a/erts/emulator/hipe/hipe_stack.h b/erts/emulator/hipe/hipe_stack.h index 4ea7d5c031..afa0ed4256 100644 --- a/erts/emulator/hipe/hipe_stack.h +++ b/erts/emulator/hipe/hipe_stack.h @@ -131,5 +131,8 @@ static __inline__ void hipe_check_nstack(Process *p, unsigned nwords) */ extern Eterm *fullsweep_nstack(Process *p, Eterm *n_htop); extern void gensweep_nstack(Process *p, Eterm **ptr_old_htop, Eterm **ptr_n_htop); +extern Eterm *sweep_literals_nstack(Process *p, Eterm *n_htop, char *area, + Uint area_size); +extern int nstack_any_heap_ref_ptrs(Process *, char* mod_start, Uint mod_size); #endif /* HIPE_STACK_H */ diff --git a/erts/emulator/hipe/hipe_x86_gc.h b/erts/emulator/hipe/hipe_x86_gc.h index c22b28c2d5..00fe03d8f9 100644 --- a/erts/emulator/hipe/hipe_x86_gc.h +++ b/erts/emulator/hipe/hipe_x86_gc.h @@ -81,6 +81,23 @@ nstack_walk_init_sdesc(const Process *p, struct nstack_walk_state *state) #endif } +static inline const struct sdesc* +nstack_walk_init_sdesc_ignore_trap(const Process *p, + struct nstack_walk_state *state) +{ +#ifdef SKIP_YOUNGEST_FRAME + unsigned long ra = p->hipe.nsp[0]; + const struct sdesc *sdesc; + if (ra == (unsigned long)nbif_stack_trap_ra) + ra = (unsigned long)p->hipe.ngra; + sdesc = hipe_find_sdesc(ra); + state->sdesc0 = sdesc; + return sdesc; +#else + return nstack_walk_init_sdesc(p, state); +#endif +} + static inline void nstack_walk_update_trap(Process *p, const struct sdesc *sdesc0) { #ifdef SKIP_YOUNGEST_FRAME diff --git a/erts/emulator/test/Makefile b/erts/emulator/test/Makefile index b580211eff..2e48c475d5 100644 --- a/erts/emulator/test/Makefile +++ b/erts/emulator/test/Makefile @@ -70,6 +70,7 @@ MODULES= \ guard_SUITE \ hash_SUITE \ hibernate_SUITE \ + hipe_SUITE \ list_bif_SUITE \ lttng_SUITE \ map_SUITE \ diff --git a/erts/emulator/test/hipe_SUITE.erl b/erts/emulator/test/hipe_SUITE.erl new file mode 100644 index 0000000000..3e682b8d88 --- /dev/null +++ b/erts/emulator/test/hipe_SUITE.erl @@ -0,0 +1,64 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2016. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% + +-module(hipe_SUITE). +-export([all/0, t_copy_literals/1]). + +all() -> + case erlang:system_info(hipe_architecture) of + undefined -> {skip, "HiPE is disabled"}; + _ -> [t_copy_literals] + end. + +t_copy_literals(doc) -> + "Check that BEAM literals referenced from HiPE stack are copied by" + " check_process_code"; +t_copy_literals(Config) when is_list(Config) -> + %% Compile the the ref_cell and literals modules. + Data = proplists:get_value(data_dir, Config), + Priv = proplists:get_value(priv_dir, Config), + RefFile = filename:join(Data, "ref_cell"), + {ok,ref_cell} = c:c(RefFile, [{outdir,Priv},native]), + true = code:is_module_native(ref_cell), + LitFile = filename:join(Data, "literals"), + {ok,literals} = c:c(LitFile, [{outdir,Priv}]), + + %% store references to literals on HiPE stacks + PA = ref_cell:start_link(), + ref_cell:call(PA, {put_res_of, fun literals:a/0}), + PB = ref_cell:start_link_deep(), + ref_cell:call(PB, {put_res_of, fun literals:b/0}), + + %% purge the literals + _ = (catch erlang:purge_module(literals)), + true = erlang:delete_module(literals), + true = erlang:purge_module(literals), + + %% check that the ex-literals are ok + [a,b,c] = ref_cell:call(PA, get), + {a,b,c} = ref_cell:call(PB, get), + + %% cleanup + ref_cell:call(PA, done), + ref_cell:call(PB, done), + _ = (catch erlang:purge_module(ref_cell)), + true = erlang:delete_module(ref_cell), + true = erlang:purge_module(ref_cell), + ok. diff --git a/erts/emulator/test/hipe_SUITE_data/literals.erl b/erts/emulator/test/hipe_SUITE_data/literals.erl new file mode 100644 index 0000000000..31e443970f --- /dev/null +++ b/erts/emulator/test/hipe_SUITE_data/literals.erl @@ -0,0 +1,26 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2016. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% + +-module(literals). + +-export([a/0, b/0]). + +a() -> [a,b,c]. +b() -> {a,b,c}. diff --git a/erts/emulator/test/hipe_SUITE_data/ref_cell.erl b/erts/emulator/test/hipe_SUITE_data/ref_cell.erl new file mode 100644 index 0000000000..2654e4077b --- /dev/null +++ b/erts/emulator/test/hipe_SUITE_data/ref_cell.erl @@ -0,0 +1,64 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2016. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% + +-module(ref_cell). + +-export([start_link/0, start_link_deep/0, call/2]). + +-compile(native). + +-define(DEPTH, 100). +-define(ALLOCS, 500). + +start_link() -> + spawn_link(fun() -> loop(undefined) end). + +start_link_deep() -> + spawn_link(fun() -> go_deep(?DEPTH) end). + +%% Create a stack large enough to get a graylimit trap placed next time there's +%% a minor gc. +go_deep(0) -> + alloc_some(?ALLOCS), + loop(undefined), + 0; +go_deep(Depth) -> + go_deep(Depth-1)+1. + +%% Do some allocation to trigger a minor gc +alloc_some(Amount) -> + Check = (Amount * (Amount + 1)) div 2, + Check = lists:sum(lists:seq(1, Amount)). + +call(Pid, Call) -> + Pid ! {Call, self()}, + receive {Pid, Res} -> Res end. + +loop(Thing) -> + receive + {done, Pid} -> Pid ! {self(), done}; + {{put_res_of, Fun}, Pid} -> + NewThing = Fun(), + Pid ! {self(), put}, + loop(NewThing); + {get, Pid} -> + Pid ! {self(), Thing}, + loop(Thing) + end. -- cgit v1.2.3