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authorSverker Eriksson <[email protected]>2014-09-03 17:13:22 +0200
committerSverker Eriksson <[email protected]>2014-09-03 17:13:22 +0200
commitb182aa2cfab793e566c92183c361e78f4d6f84cb (patch)
tree4821839fdc9c5ea0d8bdd81bd5b02785f0937ccc /erts/emulator
parentc472c3f5aafc81a409d0443c4601de43bafb53cb (diff)
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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/emulator')
-rw-r--r--erts/emulator/beam/erl_nif.c12
-rw-r--r--erts/emulator/test/nif_SUITE.erl17
-rw-r--r--erts/emulator/test/nif_SUITE_data/nif_SUITE.c21
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},