From b182aa2cfab793e566c92183c361e78f4d6f84cb Mon Sep 17 00:00:00 2001 From: Sverker Eriksson Date: Wed, 3 Sep 2014 17:13:22 +0200 Subject: 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. --- erts/emulator/beam/erl_nif.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'erts/emulator/beam') 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)); -- cgit v1.2.3