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authorBjörn Gustavsson <[email protected]>2017-11-24 12:50:25 +0100
committerBjörn Gustavsson <[email protected]>2017-11-24 15:47:32 +0100
commit3105c314beff5c9b226d8e863d32c4329706353c (patch)
tree9890c65469b078a47b7cd8a415badc93494fd89c /erts/emulator/test
parentc17978f689ca8f9dd36f76fa8fcf448664921301 (diff)
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Fix purging of modules with "fake literals"
When compiling Erlang source code, the literal area for the module can only contain data types that have a literal syntax. However, it is possible to sneak in other data types (such as references) in the literal pool by compiling from abstract or assembly code. Those "fake literals" would work fine, but would crash the runtime system when the module containing the literals was purged. Although fake literals are not officially supported, the runtime should not crash when attempting to use them. Therefore, fix the garbage collection of literals and releasing of literal areas. https://bugs.erlang.org/browse/ERL-508
Diffstat (limited to 'erts/emulator/test')
-rw-r--r--erts/emulator/test/code_SUITE.erl60
1 files changed, 59 insertions, 1 deletions
diff --git a/erts/emulator/test/code_SUITE.erl b/erts/emulator/test/code_SUITE.erl
index 77321aa50f..dca600bc7b 100644
--- a/erts/emulator/test/code_SUITE.erl
+++ b/erts/emulator/test/code_SUITE.erl
@@ -25,6 +25,7 @@
multi_proc_purge/1, t_check_old_code/1,
external_fun/1,get_chunk/1,module_md5/1,
constant_pools/1,constant_refc_binaries/1,
+ fake_literals/1,
false_dependency/1,coverage/1,fun_confusion/1,
t_copy_literals/1, t_copy_literals_frags/1]).
@@ -38,7 +39,8 @@ all() ->
call_purged_fun_code_reload, call_purged_fun_code_there,
multi_proc_purge, t_check_old_code, external_fun, get_chunk,
module_md5,
- constant_pools, constant_refc_binaries, false_dependency,
+ constant_pools, constant_refc_binaries, fake_literals,
+ false_dependency,
coverage, fun_confusion, t_copy_literals, t_copy_literals_frags].
init_per_suite(Config) ->
@@ -554,6 +556,62 @@ wait_for_memory_deallocations() ->
wait_for_memory_deallocations()
end.
+fake_literals(_Config) ->
+ Mod = fake__literals__module,
+ try
+ do_fake_literals(Mod)
+ after
+ _ = code:purge(Mod),
+ _ = code:delete(Mod),
+ _ = code:purge(Mod),
+ _ = code:delete(Mod)
+ end,
+ ok.
+
+do_fake_literals(Mod) ->
+ Tid = ets:new(test, []),
+ ExtTerms = get_external_terms(),
+ Term0 = {self(),make_ref(),Tid,fun() -> ok end,ExtTerms},
+ Terms = [begin
+ make_literal_module(Mod, Term0),
+ Mod:term()
+ end || _ <- lists:seq(1, 10)],
+ verify_lit_terms(Terms, Term0),
+ true = ets:delete(Tid),
+ ok.
+
+make_literal_module(Mod, Term) ->
+ Exp = [{term,0}],
+ Attr = [],
+ Fs = [{function,term,0,2,
+ [{label,1},
+ {line,[]},
+ {func_info,{atom,Mod},{atom,term},0},
+ {label,2},
+ {move,{literal,Term},{x,0}},
+ return]}],
+ Asm = {Mod,Exp,Attr,Fs,2},
+ {ok,Mod,Beam} = compile:forms(Asm, [from_asm,binary,report]),
+ code:load_binary(Mod, atom_to_list(Mod), Beam).
+
+verify_lit_terms([H|T], Term) ->
+ case H =:= Term of
+ true ->
+ verify_lit_terms(T, Term);
+ false ->
+ error({bad_term,H})
+ end;
+verify_lit_terms([], _) ->
+ ok.
+
+get_external_terms() ->
+ {ok,Node} = test_server:start_node(?FUNCTION_NAME, slave, []),
+ Ref = rpc:call(Node, erlang, make_ref, []),
+ Ports = rpc:call(Node, erlang, ports, []),
+ Pid = rpc:call(Node, erlang, self, []),
+ _ = test_server:stop_node(Node),
+ {Ref,hd(Ports),Pid}.
+
%% OTP-7559: c_p->cp could contain garbage and create a false dependency
%% to a module in a process. (Thanks to Richard Carlsson.)
false_dependency(Config) when is_list(Config) ->