From 491cd4c0c0a534ab89c3ebb4c413301c91c7167d Mon Sep 17 00:00:00 2001 From: Sverker Eriksson Date: Tue, 22 Nov 2016 14:37:31 +0100 Subject: erts: Add env variable ERL_CRASH_DUMP_BYTES to limit crash dump size --- erts/doc/src/erl.xml | 9 +++++++++ erts/emulator/beam/break.c | 35 +++++++++++++++++++++++++++++++++++ erts/emulator/beam/erl_init.c | 13 ++++++++++++- erts/emulator/beam/global.h | 1 + erts/emulator/test/bif_SUITE.erl | 29 +++++++++++++++++++++++++++-- 5 files changed, 84 insertions(+), 3 deletions(-) diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml index f62d3fb170..bd88016ff0 100644 --- a/erts/doc/src/erl.xml +++ b/erts/doc/src/erl.xml @@ -1533,6 +1533,15 @@ + + +

This variable sets the maximum size of a crash dump file in bytes. + The crash dump will be truncated if this limit is exceeded. If the + variable is not set, no size limit is enforced by default. If the + variable is set to 0, the runtime system does not even attempt + to write a crash dump file.

+

Introduced in ERTS 8.1.2 (Erlang/OTP 19.2).

+

The content of this variable is added to the beginning of the diff --git a/erts/emulator/beam/break.c b/erts/emulator/beam/break.c index 2e8a384dec..33433df68a 100644 --- a/erts/emulator/beam/break.c +++ b/erts/emulator/beam/break.c @@ -661,6 +661,26 @@ bin_check(void) #endif +static Sint64 crash_dump_limit = ERTS_SINT64_MAX; +static Sint64 crash_dump_written = 0; + +static int crash_dump_limited_writer(void* vfdp, char* buf, size_t len) +{ + const char stop_msg[] = "\n=abort: CRASH DUMP SIZE LIMIT REACHED\n"; + + crash_dump_written += len; + if (crash_dump_written <= crash_dump_limit) { + return erts_write_fd(vfdp, buf, len); + } + + len -= (crash_dump_written - crash_dump_limit); + erts_write_fd(vfdp, buf, len); + erts_write_fd(vfdp, (char*)stop_msg, sizeof(stop_msg)-1); + + /* We assume that crash dump was called from erts_exit_vv() */ + erts_exit_epilogue(); +} + /* XXX THIS SHOULD BE IN SYSTEM !!!! */ void erl_crash_dump_v(char *file, int line, char* fmt, va_list args) @@ -760,6 +780,21 @@ erl_crash_dump_v(char *file, int line, char* fmt, va_list args) return; } + crash_dump_limit = ERTS_SINT64_MAX; + envsz = sizeof(env); + if (erts_sys_getenv__("ERL_CRASH_DUMP_BYTES", env, &envsz) == 0) { + Sint64 limit; + char* endptr; + errno = 0; + limit = ErtsStrToSint64(env, &endptr, 10); + if (errno == 0 && limit >= 0 && endptr != env && *endptr == 0) { + if (limit == 0) + return; + crash_dump_limit = limit; + to = &crash_dump_limited_writer; + } + } + if (erts_sys_getenv__("ERL_CRASH_DUMP",&dumpnamebuf[0],&dumpnamebufsize) != 0) dumpname = "erl_crash.dump"; else diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c index 781bf024dd..362239f765 100644 --- a/erts/emulator/beam/erl_init.c +++ b/erts/emulator/beam/erl_init.c @@ -2374,6 +2374,8 @@ system_cleanup(int flush_async) erts_exit_flush_async(); } +static int erts_exit_code; + static __decl_noreturn void __noreturn erts_exit_vv(int n, int flush_async, char *fmt, va_list args1, va_list args2) { @@ -2385,12 +2387,21 @@ erts_exit_vv(int n, int flush_async, char *fmt, va_list args1, va_list args2) if (fmt != NULL && *fmt != '\0') erl_error(fmt, args2); /* Print error message. */ - /* Produce an Erlang core dump if error */ + erts_exit_code = n; + + /* Produce an Erlang crash dump if error */ if (((n == ERTS_ERROR_EXIT && erts_no_crash_dump == 0) || n == ERTS_DUMP_EXIT) && erts_initialized) { erl_crash_dump_v((char*) NULL, 0, fmt, args1); } + erts_exit_epilogue(); +} + +__decl_noreturn void __noreturn erts_exit_epilogue(void) +{ + int n = erts_exit_code; + sys_tty_reset(n); if (n == ERTS_INTR_EXIT) diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h index 244e5edeb6..d6df85034c 100644 --- a/erts/emulator/beam/global.h +++ b/erts/emulator/beam/global.h @@ -1079,6 +1079,7 @@ double erts_get_positive_zero_float(void); /* config.c */ +__decl_noreturn void __noreturn erts_exit_epilogue(void); __decl_noreturn void __noreturn erts_exit(int n, char*, ...); __decl_noreturn void __noreturn erts_flush_async_exit(int n, char*, ...); void erl_error(char*, va_list); diff --git a/erts/emulator/test/bif_SUITE.erl b/erts/emulator/test/bif_SUITE.erl index d31399e4af..b8d89126fe 100644 --- a/erts/emulator/test/bif_SUITE.erl +++ b/erts/emulator/test/bif_SUITE.erl @@ -31,6 +31,7 @@ t_list_to_existing_atom/1,os_env/1,otp_7526/1, binary_to_atom/1,binary_to_existing_atom/1, atom_to_binary/1,min_max/1, erlang_halt/1, + erl_crash_dump_bytes/1, is_builtin/1]). suite() -> @@ -43,6 +44,7 @@ all() -> t_list_to_existing_atom, os_env, otp_7526, display, atom_to_binary, binary_to_atom, binary_to_existing_atom, + erl_crash_dump_bytes, min_max, erlang_halt, is_builtin]. %% Uses erlang:display to test that erts_printf does not do deep recursion @@ -664,7 +666,7 @@ erlang_halt(Config) when is_list(Config) -> [available_internal_state, true]), {badrpc,nodedown} = rpc:call(N4, erts_debug, set_internal_state, [broken_halt, "Validate correct crash dump"]), - ok = wait_until_stable_size(CrashDump,-1), + {ok,_} = wait_until_stable_size(CrashDump,-1), {ok, Bin} = file:read_file(CrashDump), case {string:str(binary_to_list(Bin),"\n=end\n"), string:str(binary_to_list(Bin),"\r\n=end\r\n")} of @@ -681,11 +683,34 @@ wait_until_stable_size(File,PrevSz) -> wait_until_stable_size(File,PrevSz-1); {ok,#file_info{size = PrevSz }} when PrevSz /= -1 -> io:format("Crashdump file size was: ~p (~s)~n",[PrevSz,File]), - ok; + {ok,PrevSz}; {ok,#file_info{size = NewSz }} -> wait_until_stable_size(File,NewSz) end. +% Test erlang:halt with ERL_CRASH_DUMP_BYTES +erl_crash_dump_bytes(Config) when is_list(Config) -> + Bytes = 1000, + CrashDump = do_limited_crash_dump(Config, Bytes), + {ok,ActualBytes} = wait_until_stable_size(CrashDump,-1), + true = ActualBytes < (Bytes + 100), + + NoDump = do_limited_crash_dump(Config,0), + {error,enoent} = wait_until_stable_size(NoDump,-8), + ok. + +do_limited_crash_dump(Config, Bytes) -> + H = hostname(), + {ok,N} = slave:start(H, halt_node), + BytesStr = integer_to_list(Bytes), + CrashDump = filename:join(proplists:get_value(priv_dir,Config), + "erl_crash." ++ BytesStr ++ ".dump"), + true = rpc:call(N, os, putenv, ["ERL_CRASH_DUMP",CrashDump]), + true = rpc:call(N, os, putenv, ["ERL_CRASH_DUMP_BYTES",BytesStr]), + {badrpc,nodedown} = rpc:call(N, erlang, halt, ["Testing ERL_CRASH_DUMP_BYTES"]), + CrashDump. + + is_builtin(_Config) -> Exp0 = [{M,F,A} || {M,_} <- code:all_loaded(), {F,A} <- M:module_info(exports)], -- cgit v1.2.3