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author | Sverker Eriksson <sverker@erlang.org> | 2014-09-03 17:13:22 +0200 |
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committer | Sverker Eriksson <sverker@erlang.org> | 2014-09-03 17:13:22 +0200 |
commit | b182aa2cfab793e566c92183c361e78f4d6f84cb (patch) | |
tree | 4821839fdc9c5ea0d8bdd81bd5b02785f0937ccc /erts | |
parent | c472c3f5aafc81a409d0443c4601de43bafb53cb (diff) | |
download | otp-b182aa2cfab793e566c92183c361e78f4d6f84cb.tar.gz otp-b182aa2cfab793e566c92183c361e78f4d6f84cb.tar.bz2 otp-b182aa2cfab793e566c92183c361e78f4d6f84cb.zip |
erts: Fix bug with enif_make_copy reallocating writable binary
that could invalidate a pointer received from an earlier
call to enif_inspect_binary.
Solution: Emasculate writable binary at enif_inspect_binary. There are
room for optimizations here as we now do an unconditional emasculation
even though enif_make_copy is not called later in the NIF.
Diffstat (limited to 'erts')
-rw-r--r-- | erts/emulator/beam/erl_nif.c | 12 | ||||
-rw-r--r-- | erts/emulator/test/nif_SUITE.erl | 17 | ||||
-rw-r--r-- | erts/emulator/test/nif_SUITE_data/nif_SUITE.c | 21 |
3 files changed, 50 insertions, 0 deletions
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c index ff551ea3af..8c4bf73dbe 100644 --- a/erts/emulator/beam/erl_nif.c +++ b/erts/emulator/beam/erl_nif.c @@ -472,6 +472,18 @@ int enif_inspect_binary(ErlNifEnv* env, Eterm bin_term, ErlNifBinary* bin) struct enif_tmp_obj_t* tmp; byte* raw_ptr; }u; + + if (is_boxed(bin_term) && *binary_val(bin_term) == HEADER_SUB_BIN) { + ErlSubBin* sb = (ErlSubBin*) binary_val(bin_term); + if (sb->is_writable) { + ProcBin* pb = (ProcBin*) binary_val(sb->orig); + ASSERT(pb->thing_word == HEADER_PROC_BIN); + if (pb->flags) { + erts_emasculate_writable_binary(pb); + sb->is_writable = 0; + } + } + } u.tmp = NULL; bin->data = erts_get_aligned_binary_bytes_extra(bin_term, &u.raw_ptr, allocator, sizeof(struct enif_tmp_obj_t)); diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl index b2da6f58af..2e9b4aeab1 100644 --- a/erts/emulator/test/nif_SUITE.erl +++ b/erts/emulator/test/nif_SUITE.erl @@ -37,6 +37,7 @@ threading/1, send/1, send2/1, send3/1, send_threaded/1, neg/1, is_checks/1, get_length/1, make_atom/1, make_string/1, reverse_list_test/1, + otp_9828/1, otp_9668/1, consume_timeslice/1, dirty_nif/1, dirty_nif_send/1 ]). @@ -64,6 +65,7 @@ all() -> resource_takeover, threading, send, send2, send3, send_threaded, neg, is_checks, get_length, make_atom, make_string,reverse_list_test, + otp_9828, otp_9668, consume_timeslice, dirty_nif, dirty_nif_send ]. @@ -1440,6 +1442,20 @@ otp_9668(Config) -> ?line verify_tmpmem(TmpMem), ok. +otp_9828(doc) -> ["Copy of writable binary"]; +otp_9828(Config) -> + ensure_lib_loaded(Config, 1), + + otp_9828_loop(<<"I'm alive!">>, 1000). + +otp_9828_loop(Bin, 0) -> + ok; +otp_9828_loop(Bin, Val) -> + WrtBin = <<Bin/binary, Val:32>>, + ok = otp_9828_nif(WrtBin), + otp_9828_loop(WrtBin, Val-1). + + consume_timeslice(Config) when is_list(Config) -> CONTEXT_REDS = 2000, Me = self(), @@ -1684,6 +1700,7 @@ reverse_list(_) -> ?nif_stub. echo_int(_) -> ?nif_stub. type_sizes() -> ?nif_stub. otp_9668_nif(_) -> ?nif_stub. +otp_9828_nif(_) -> ?nif_stub. consume_timeslice_nif(_,_) -> ?nif_stub. call_dirty_nif(_,_,_) -> ?nif_stub. send_from_dirty_nif(_) -> ?nif_stub. diff --git a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c index 955dc64189..25e20f3e7d 100644 --- a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c +++ b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c @@ -1473,6 +1473,26 @@ static ERL_NIF_TERM otp_9668_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM ar return atom_ok; } +static ERL_NIF_TERM otp_9828_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{ + /* copy a writable binary could reallocate it due to "emasculation" + and thereby render a previous inspection invalid. + */ + ErlNifBinary bin1; + ErlNifEnv* myenv; + + if (!enif_inspect_binary(env, argv[0], &bin1)) { + return enif_make_badarg(env); + } + + myenv = enif_alloc_env(); + enif_make_copy(myenv, argv[0]); + enif_free_env(myenv); + + return memcmp(bin1.data, "I'm alive!", 10)==0 ? atom_ok : atom_false; +} + + static ERL_NIF_TERM consume_timeslice_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) { int percent; @@ -1741,6 +1761,7 @@ static ErlNifFunc nif_funcs[] = {"echo_int", 1, echo_int}, {"type_sizes", 0, type_sizes}, {"otp_9668_nif", 1, otp_9668_nif}, + {"otp_9828_nif", 1, otp_9828_nif}, {"consume_timeslice_nif", 2, consume_timeslice_nif}, #ifdef ERL_NIF_DIRTY_SCHEDULER_SUPPORT {"call_dirty_nif", 3, call_dirty_nif}, |