From 0a144d1fc4bebefcc74b0cb63fe76809bc041789 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Fri, 17 Feb 2017 15:26:01 +0100 Subject: Ensure prim_eval:'receive' wont clobber def_arg_reg[0] def_arg_reg[0] is used for storage of timeout instruction when a 'receive after' is executed. When a process was scheduled out inside prim_eval:'receive'/0 due to a function call, def_arg_reg[0] was overwritten due to storage of live registers. prim_eval:'receive'/2 now calls arg_reg_alloc/0 which bumps all reductions and then calls arg_reg_alloc/7 which will cause an allocation of a new arg_reg array since def_arg_reg only can hold 6 values. This ensures that the timeout instruction in def_arg_reg[0] used for the timeout wont be overwritten. --- erts/emulator/test/Makefile | 1 + erts/emulator/test/prim_eval_SUITE.erl | 78 +++++++++++++++++++++++++++++++++ erts/preloaded/ebin/prim_eval.beam | Bin 1300 -> 1448 bytes erts/preloaded/src/prim_eval.S | 41 ++++++++++++++--- 4 files changed, 113 insertions(+), 7 deletions(-) create mode 100644 erts/emulator/test/prim_eval_SUITE.erl (limited to 'erts') diff --git a/erts/emulator/test/Makefile b/erts/emulator/test/Makefile index 2e48c475d5..453f819d1b 100644 --- a/erts/emulator/test/Makefile +++ b/erts/emulator/test/Makefile @@ -87,6 +87,7 @@ MODULES= \ op_SUITE \ port_SUITE \ port_bif_SUITE \ + prim_eval_SUITE \ process_SUITE \ pseudoknot_SUITE \ receive_SUITE \ diff --git a/erts/emulator/test/prim_eval_SUITE.erl b/erts/emulator/test/prim_eval_SUITE.erl new file mode 100644 index 0000000000..3f4965f96d --- /dev/null +++ b/erts/emulator/test/prim_eval_SUITE.erl @@ -0,0 +1,78 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2017. 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(prim_eval_SUITE). +-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, + init_per_testcase/2, end_per_testcase/2, + init_per_group/2, end_per_group/2]). + +-export(['ERL-365'/1]). + +init_per_testcase(_Case, Config) -> + Config. + +end_per_testcase(_Case, _Config) -> + ok. + +suite() -> + [{ct_hooks,[ts_install_cth]}, + {timetrap,{minutes,1}}]. + +groups() -> + []. + +init_per_suite(Config) -> + Config. + +end_per_suite(_Config) -> + ok. + +init_per_group(_GroupName, Config) -> + Config. + +end_per_group(_GroupName, Config) -> + Config. + +all() -> + ['ERL-365']. + +'ERL-365'(Config) when is_list(Config) -> + %% def_arg_reg[0] is used for storage of timeout instruction + %% when a 'receive after' is executed. When a process was + %% scheduled out inside prim_eval:'receive'/0 due to a function + %% call, def_arg_reg[0] was overwritten due to storage of live + %% registers. + P = spawn_link(fun () -> + prim_eval:'receive'(fun (_M) -> + erlang:bump_reductions((1 bsl 27)-1), + id(true), + nomatch + end, + 200) + end), + receive after 100 -> ok end, + P ! {wont, match}, + receive after 200 -> ok end, + ok. + + + +id(X) -> + X. diff --git a/erts/preloaded/ebin/prim_eval.beam b/erts/preloaded/ebin/prim_eval.beam index a50a628a27..49fd62490e 100644 Binary files a/erts/preloaded/ebin/prim_eval.beam and b/erts/preloaded/ebin/prim_eval.beam differ diff --git a/erts/preloaded/src/prim_eval.S b/erts/preloaded/src/prim_eval.S index e7f09a870c..c6623f8e03 100644 --- a/erts/preloaded/src/prim_eval.S +++ b/erts/preloaded/src/prim_eval.S @@ -26,7 +26,7 @@ {attributes, []}. -{labels, 10}. +{labels, 14}. {function, 'receive', 2, 2}. @@ -36,6 +36,9 @@ {allocate,2,2}. {move,{x,1},{y,0}}. {move,{x,0},{y,1}}. + %% Call arg_reg_alloc() in order to ensure + %% that def_arg_reg[0] isn't clobbered + {call,0,{f,7}}. {label,3}. {loop_rec,{f,5},{x,0}}. {move,{y,1},{x,1}}. @@ -53,19 +56,43 @@ {deallocate,2}. return. - -{function, module_info, 0, 8}. +{function, arg_reg_alloc, 0, 7}. {label,6}. - {func_info,{atom,prim_eval},{atom,module_info},0}. + {func_info,{atom,prim_eval},{atom,arg_reg_alloc},0}. {label,7}. + {allocate,0,0}. + {move,{integer,134217727},{x,0}}. + {call_ext,1,{extfunc,erlang,bump_reductions,1}}. + {move,{atom,true},{x,3}}. + {move,{atom,true},{x,4}}. + {move,{atom,true},{x,2}}. + {move,{atom,true},{x,5}}. + {move,{atom,true},{x,1}}. + {move,{atom,true},{x,6}}. + {move,{atom,true},{x,0}}. + {call_last,7,{f,9},0}. + + +{function, arg_reg_alloc, 7, 9}. + {label,8}. + {func_info,{atom,prim_eval},{atom,arg_reg_alloc},7}. + {label,9}. + {move,{atom,ok},{x,0}}. + return. + + +{function, module_info, 0, 11}. + {label,10}. + {func_info,{atom,prim_eval},{atom,module_info},0}. + {label,11}. {move,{atom,prim_eval},{x,0}}. {call_ext_only,1,{extfunc,erlang,get_module_info,1}}. -{function, module_info, 1, 10}. - {label,8}. +{function, module_info, 1, 13}. + {label,12}. {func_info,{atom,prim_eval},{atom,module_info},1}. - {label,9}. + {label,13}. {move,{x,0},{x,1}}. {move,{atom,prim_eval},{x,0}}. {call_ext_only,2,{extfunc,erlang,get_module_info,2}}. -- cgit v1.2.3