Pack struct iter_method_arg (40 -> 32 bytes) #5

methodmissing · 2019-12-12T00:15:20Z

Before:

lourens@CarbonX1:~/src/ruby/ruby$ pahole -C iter_method_arg ./miniruby
struct iter_method_arg {
	VALUE                      obj;                  /*     0     8 */
	ID                         mid;                  /*     8     8 */
	int                        argc;                 /*    16     4 */

	/* XXX 4 bytes hole, try to pack */

	const VALUE  *             argv;                 /*    24     8 */
	int                        kw_splat;             /*    32     4 */

	/* size: 40, cachelines: 1, members: 5 */
	/* sum members: 32, holes: 1, sum holes: 4 */
	/* padding: 4 */
	/* last cacheline: 40 bytes */
};

After:

lourens@CarbonX1:~/src/ruby/ruby$ pahole -C iter_method_arg ./miniruby
struct iter_method_arg {
	VALUE                      obj;                  /*     0     8 */
	ID                         mid;                  /*     8     8 */
	int                        argc;                 /*    16     4 */
	int                        kw_splat;             /*    20     4 */
	const VALUE  *             argv;                 /*    24     8 */

	/* size: 32, cachelines: 1, members: 5 */
	/* last cacheline: 32 bytes */
};

This changeset makes no difference unless GC_DEBUG is on. When that flag is set, struct RVALUE is bigger than struct RObject. We have to take care of the additional fields. Otherwise we get a SIGSEGV like shown below. The way obj is initialized in this patch works for both GC_DEBUG is on and off. See also ISO/IEC 9899:1999 section 6.7.8 paragraph #21. ``` Program received signal SIGSEGV, Segmentation fault. __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:62 62 ../sysdeps/x86_64/multiarch/strlen-avx2.S: No such file or directory (gdb) bt #0 __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:62 #1 0x00005555557dd9a7 in BSD_vfprintf (fp=0x7fffffff6be0, fmt0=0x5555558f3059 "@%s:%d", ap=0x7fffffff6dd0) at vsnprintf.c:1027 #2 0x00005555557db6f5 in ruby_do_vsnprintf (str=0x555555bfc58d <obj_info_buffers+1325> "", n=211, fmt=0x5555558f3059 "@%s:%d", ap=0x7fffffff6dd0) at sprintf.c:1022 #3 0x00005555557db909 in ruby_snprintf (str=0x555555bfc58d <obj_info_buffers+1325> "", n=211, fmt=0x5555558f3059 "@%s:%d") at sprintf.c:1040 #4 0x0000555555661ef4 in rb_raw_obj_info (buff=0x555555bfc560 <obj_info_buffers+1280> "0x0000555555d2bfa0 [0 ] T_STRING (String)", buff_size=256, obj=93825000456096) at gc.c:11449 #5 0x000055555565baaf in obj_info (obj=93825000456096) at gc.c:11612 #6 0x000055555565bae1 in rgengc_remembered (objspace=0x555555c0a1c0, obj=93825000456096) at gc.c:6618 #7 0x0000555555666987 in newobj_init (klass=93824999964192, flags=5, v1=0, v2=0, v3=0, wb_protected=1, objspace=0x555555c0a1c0, obj=93825000456096) at gc.c:2134 #8 0x0000555555666e49 in newobj_slowpath (klass=93824999964192, flags=5, v1=0, v2=0, v3=0, objspace=0x555555c0a1c0, wb_protected=1) at gc.c:2209 #9 0x0000555555666b94 in newobj_slowpath_wb_protected (klass=93824999964192, flags=5, v1=0, v2=0, v3=0, objspace=0x555555c0a1c0) at gc.c:2220 #10 0x000055555565751b in newobj_of (klass=93824999964192, flags=5, v1=0, v2=0, v3=0, wb_protected=1) at gc.c:2256 #11 0x00005555556575ca in rb_wb_protected_newobj_of (klass=93824999964192, flags=5) at gc.c:2272 #12 0x00005555557f36ea in str_alloc (klass=93824999964192) at string.c:728 #13 0x00005555557f2128 in rb_str_buf_new (capa=0) at string.c:1317 #14 0x000055555578c66d in rb_reg_preprocess (p=0x555555cc8148 "^-(.)(.+)?", end=0x555555cc8152 "", enc=0x555555cc7c80, fixed_enc=0x7fffffff74e8, err=0x7fffffff75f0 "") at re.c:2682 #15 0x000055555578ea13 in rb_reg_initialize (obj=93825000046736, s=0x555555cc8148 "^-(.)(.+)?", len=10, enc=0x555555cc7c80, options=0, err=0x7fffffff75f0 "", sourcefile=0x555555d1a5c0 "lib/optparse.rb", sourceline=1460) at re.c:2808 #16 0x000055555578e285 in rb_reg_initialize_str (obj=93825000046736, str=93825000046904, options=0, err=0x7fffffff75f0 "", sourcefile=0x555555d1a5c0 "lib/optparse.rb", sourceline=1460) at re.c:2869 #17 0x000055555578ee02 in rb_reg_compile (str=93825000046904, options=0, sourcefile=0x555555d1a5c0 "lib/optparse.rb", sourceline=1460) at re.c:2958 #18 0x0000555555748dfb in rb_parser_reg_compile (p=0x555555d1f760, str=93825000046904, options=0) at parse.y:12157 #19 0x00005555557581c3 in parser_reg_compile (p=0x555555d1f760, str=93825000046904, options=0) at parse.y:12151 #20 0x00005555557580ac in reg_compile (p=0x555555d1f760, str=93825000046904, options=0) at parse.y:12167 #21 0x0000555555746ebb in new_regexp (p=0x555555d1f760, node=0x555555dece68, options=0, loc=0x7fffffff89e8) at parse.y:10072 #22 0x000055555573d1f5 in ruby_yyparse (p=0x555555d1f760) at parse.y:4395 #23 0x000055555574a582 in yycompile0 (arg=93825000404832) at parse.y:5945 #24 0x00005555558c6898 in rb_suppress_tracing (func=0x55555574a470 <yycompile0>, arg=93825000404832) at vm_trace.c:427 #25 0x0000555555748290 in yycompile (vparser=93824999283456, p=0x555555d1f760, fname=93824999283624, line=1) at parse.y:5994 #26 0x00005555557481ae in rb_parser_compile_file_path (vparser=93824999283456, fname=93824999283624, file=93824999283400, start=1) at parse.y:6098 #27 0x00005555557cdd35 in load_file_internal (argp_v=140737488331760) at ruby.c:2023 #28 0x00005555556438c5 in rb_ensure (b_proc=0x5555557cd610 <load_file_internal>, data1=140737488331760, e_proc=0x5555557cddd0 <restore_load_file>, data2=140737488331760) at eval.c:1128 #29 0x00005555557cb68b in load_file (parser=93824999283456, fname=93824999283624, f=93824999283400, script=0, opt=0x7fffffffa468) at ruby.c:2142 #30 0x00005555557cb339 in rb_parser_load_file (parser=93824999283456, fname_v=93824999283624) at ruby.c:2164 #31 0x00005555556ba3e1 in load_iseq_eval (ec=0x555555c0a650, fname=93824999283624) at load.c:579 #32 0x00005555556b857a in require_internal (ec=0x555555c0a650, fname=93824999284352, exception=1) at load.c:1016 #33 0x00005555556b7967 in rb_require_string (fname=93824999284464) at load.c:1105 #34 0x00005555556b7939 in rb_f_require (obj=93824999994824, fname=93824999284464) at load.c:811 #35 0x00005555558b7ae0 in call_cfunc_1 (recv=93824999994824, argc=1, argv=0x7ffff7ecd0a8, func=0x5555556b7920 <rb_f_require>) at vm_insnhelper.c:2348 #36 0x00005555558a8889 in vm_call_cfunc_with_frame (ec=0x555555c0a650, reg_cfp=0x7ffff7fccfa0, calling=0x7fffffffaab0, cd=0x555555d76a10, empty_kw_splat=0) at vm_insnhelper.c:2513 #37 0x000055555589fb5c in vm_call_cfunc (ec=0x555555c0a650, reg_cfp=0x7ffff7fccfa0, calling=0x7fffffffaab0, cd=0x555555d76a10) at vm_insnhelper.c:2538 #38 0x000055555589f22e in vm_call_method_each_type (ec=0x555555c0a650, cfp=0x7ffff7fccfa0, calling=0x7fffffffaab0, cd=0x555555d76a10) at vm_insnhelper.c:2924 #39 0x000055555589ef47 in vm_call_method (ec=0x555555c0a650, cfp=0x7ffff7fccfa0, calling=0x7fffffffaab0, cd=0x555555d76a10) at vm_insnhelper.c:3038 #40 0x0000555555866dbd in vm_call_general (ec=0x555555c0a650, reg_cfp=0x7ffff7fccfa0, calling=0x7fffffffaab0, cd=0x555555d76a10) at vm_insnhelper.c:3075 #41 0x00005555558ae557 in vm_sendish (ec=0x555555c0a650, reg_cfp=0x7ffff7fccfa0, cd=0x555555d76a10, block_handler=0, method_explorer=0x5555558ae5d0 <vm_search_method_wrap>) at vm_insnhelper.c:4021 #42 0x000055555587745b in vm_exec_core (ec=0x555555c0a650, initial=0) at insns.def:801 #43 0x0000555555899b9c in rb_vm_exec (ec=0x555555c0a650, mjit_enable_p=1) at vm.c:1907 #44 0x000055555589aaf0 in rb_iseq_eval_main (iseq=0x555555c1da80) at vm.c:2166 #45 0x0000555555641f0b in rb_ec_exec_node (ec=0x555555c0a650, n=0x555555c1da80) at eval.c:277 #46 0x0000555555641d62 in ruby_run_node (n=0x555555c1da80) at eval.c:335 #47 0x000055555557a188 in main (argc=11, argv=0x7fffffffc848) at main.c:50 (gdb) fr 7 #7 0x0000555555666987 in newobj_init (klass=93824999964192, flags=5, v1=0, v2=0, v3=0, wb_protected=1, objspace=0x555555c0a1c0, obj=93825000456096) at gc.c:2134 2134 if (rgengc_remembered(objspace, (VALUE)obj)) rb_bug("newobj: %s is remembered.", obj_info(obj)); (gdb) p ((struct RVALUE*)obj)->file $1 = 0x65a5992b0fb25ce7 <error: Cannot access memory at address 0x65a5992b0fb25ce7> (gdb) ```

This reverts commit 02b216e. This reverts commit 9b8825b. I found that combining sweep and move is not safe. I don't think that we can do compaction concurrently with _anything_ unless there is a read barrier installed. Here is a simple example. A class object is freed, and during it's free step, it tries to remove itself from its parent's subclass list. However, during the sweep step, the parent class was moved and the "currently being freed" class didn't have references updated yet. So we get a segv like this: ``` (lldb) bt * thread #1, name = 'ruby', stop reason = signal SIGSEGV * frame #0: 0x0000560763e344cb ruby`rb_st_lookup at st.c:320:43 frame #1: 0x0000560763e344cb ruby`rb_st_lookup(tab=0x2f7469672f6e6f72, key=3809, value=0x0000560765bf2270) at st.c:1010 frame #2: 0x0000560763e8f16a ruby`rb_search_class_path at variable.c:99:9 frame #3: 0x0000560763e8f141 ruby`rb_search_class_path at variable.c:145 frame #4: 0x0000560763e8f141 ruby`rb_search_class_path(klass=94589785585880) at variable.c:191 frame #5: 0x0000560763ec744e ruby`rb_vm_bugreport at vm_dump.c:996:17 frame #6: 0x0000560763f5b958 ruby`rb_bug_for_fatal_signal at error.c:675:5 frame #7: 0x0000560763e27dad ruby`sigsegv(sig=<unavailable>, info=<unavailable>, ctx=<unavailable>) at signal.c:955:5 frame #8: 0x00007f8b891d33c0 libpthread.so.0`___lldb_unnamed_symbol1$$libpthread.so.0 + 1 frame #9: 0x0000560763efa8bb ruby`rb_class_remove_from_super_subclasses(klass=94589790314280) at class.c:93:56 frame #10: 0x0000560763d10cb7 ruby`gc_sweep_step at gc.c:2674:2 frame #11: 0x0000560763d1187b ruby`gc_sweep at gc.c:4540:2 frame #12: 0x0000560763d101f0 ruby`gc_start at gc.c:6797:6 frame #13: 0x0000560763d15153 ruby`rb_gc_compact at gc.c:7479:12 frame #14: 0x0000560763eb4eb8 ruby`vm_exec_core at vm_insnhelper.c:5183:13 frame #15: 0x0000560763ea9bae ruby`rb_vm_exec at vm.c:1953:22 frame #16: 0x0000560763eac08d ruby`rb_yield at vm.c:1132:9 frame #17: 0x0000560763edb4f2 ruby`rb_ary_collect at array.c:3186:9 frame #18: 0x0000560763e9ee15 ruby`vm_call_cfunc_with_frame at vm_insnhelper.c:2575:12 frame #19: 0x0000560763eb2e66 ruby`vm_exec_core at vm_insnhelper.c:4177:11 frame #20: 0x0000560763ea9bae ruby`rb_vm_exec at vm.c:1953:22 frame #21: 0x0000560763eac08d ruby`rb_yield at vm.c:1132:9 frame #22: 0x0000560763edb4f2 ruby`rb_ary_collect at array.c:3186:9 frame #23: 0x0000560763e9ee15 ruby`vm_call_cfunc_with_frame at vm_insnhelper.c:2575:12 frame #24: 0x0000560763eb2e66 ruby`vm_exec_core at vm_insnhelper.c:4177:11 frame #25: 0x0000560763ea9bae ruby`rb_vm_exec at vm.c:1953:22 frame #26: 0x0000560763ceee01 ruby`rb_ec_exec_node(ec=0x0000560765afa530, n=0x0000560765b088e0) at eval.c:296:2 frame #27: 0x0000560763cf3b7b ruby`ruby_run_node(n=0x0000560765b088e0) at eval.c:354:12 frame #28: 0x0000560763cee4a3 ruby`main(argc=<unavailable>, argv=<unavailable>) at main.c:50:9 frame #29: 0x00007f8b88e560b3 libc.so.6`__libc_start_main + 243 frame #30: 0x0000560763cee4ee ruby`_start + 46 (lldb) f 9 frame #9: 0x0000560763efa8bb ruby`rb_class_remove_from_super_subclasses(klass=94589790314280) at class.c:93:56 90 91 *RCLASS_EXT(klass)->parent_subclasses = entry->next; 92 if (entry->next) { -> 93 RCLASS_EXT(entry->next->klass)->parent_subclasses = RCLASS_EXT(klass)->parent_subclasses; 94 } 95 xfree(entry); 96 } (lldb) command script import -r misc/lldb_cruby.py lldb scripts for ruby has been installed. (lldb) rp entry->next->klass (struct RMoved) $1 = (flags = 30, destination = 94589792806680, next = 94589784369160) (lldb) ```

maximecb · 2021-01-25T21:28:53Z

I'm going to close this because it looks inactive. Feel free to reopen it if you still want to work on it.

This commit adds a check on the ep just like in the mark function. The env can contain null bytes if allocation tracing is enabled. We're seeing errors during autocompaction like this: ``` (lldb) bt 40 * thread #1, name = 'ruby', stop reason = signal SIGABRT frame #0: 0x00007f7d64b6018b libc.so.6`raise + 203 frame #1: 0x00007f7d64b3f859 libc.so.6`abort + 299 frame #2: 0x000055af5f2fefc9 ruby`die at error.c:764:5 frame #3: 0x000055af5f2ff1ac ruby`rb_bug_for_fatal_signal(default_sighandler=0x0000000000000000, sig=11, ctx=0x000055af60bc3340, fmt="") at error.c:804:5 frame #4: 0x000055af5f4bd08f ruby`sigsegv(sig=11, info=0x000055af60bc3470, ctx=0x000055af60bc3340) at signal.c:960:5 frame #5: 0x00007f7d64ebe3c0 libpthread.so.0`__restore_rt frame #6: 0x000055af5f339b0a ruby`gc_ref_update_imemo(objspace=0x000055af60b2b040, obj=0x00007f7d5b513fd0) at gc.c:9046:13 frame #7: 0x000055af5f339172 ruby`gc_update_object_references(objspace=0x000055af60b2b040, obj=0x00007f7d5b513fd0) at gc.c:9307:9 frame #8: 0x000055af5f338e79 ruby`gc_ref_update(vstart=0x00007f7d5b510010, vend=0x00007f7d5b513ff8, stride=40, objspace=0x000055af60b2b040, page=0x000055af62577aa0) at gc.c:9452:21 frame #9: 0x000055af5f337846 ruby`gc_update_references(objspace=0x000055af60b2b040, heap=0x000055af60b2b068) at gc.c:9481:9 frame #10: 0x000055af5f336569 ruby`gc_compact_finish(objspace=0x000055af60b2b040, heap=0x000055af60b2b068) at gc.c:4840:5 frame #11: 0x000055af5f335efb ruby`gc_page_sweep(objspace=0x000055af60b2b040, heap=0x000055af60b2b068, sweep_page=0x000055af63a1eb30) at gc.c:5046:13 frame #12: 0x000055af5f3355c5 ruby`gc_sweep_step(objspace=0x000055af60b2b040, heap=0x000055af60b2b068) at gc.c:5214:19 frame #13: 0x000055af5f33daf6 ruby`gc_sweep_rest(objspace=0x000055af60b2b040) at gc.c:5271:2 frame #14: 0x000055af5f33cacd ruby`gc_sweep(objspace=0x000055af60b2b040) at gc.c:5389:2 frame #15: 0x000055af5f33c21d ruby`gc_marks_rest(objspace=0x000055af60b2b040) at gc.c:7555:5 frame #16: 0x000055af5f324d41 ruby`gc_rest(objspace=0x000055af60b2b040) at gc.c:8457:13 frame #17: 0x000055af5f3297d8 ruby`garbage_collect(objspace=0x000055af60b2b040, reason=45568) at gc.c:8318:9 frame #18: 0x000055af5f344ece ruby`garbage_collect_with_gvl(objspace=0x000055af60b2b040, reason=45568) at gc.c:8632:9 frame #19: 0x000055af5f344e61 ruby`objspace_malloc_gc_stress(objspace=0x000055af60b2b040) at gc.c:10592:9 frame #20: 0x000055af5f32ced1 ruby`objspace_xmalloc0(objspace=0x000055af60b2b040, size=64) at gc.c:10767:5 frame #21: 0x000055af5f32ce11 ruby`ruby_xmalloc0(size=64) at gc.c:10988:12 frame #22: 0x000055af5f32cdac ruby`ruby_xmalloc_body(size=64) at gc.c:10997:12 frame #23: 0x000055af5f329415 ruby`ruby_xmalloc(size=64) at gc.c:12942:12 frame #24: 0x00007f7d611c4fe5 objspace.so`newobj_i(tpval=0x00007f7d5b553770, data=0x000055af639031a0) at object_tracing.c:101:35 frame #25: 0x000055af5f5b283f ruby`tp_call_trace(tpval=0x00007f7d5b553770, trace_arg=0x00007fff1016d398) at vm_trace.c:1115:2 frame #26: 0x000055af5f5b50ec ruby`exec_hooks_body(ec=0x000055af60b2b700, list=0x000055af60b2b920, trace_arg=0x00007fff1016d398) at vm_trace.c:304:3 frame #27: 0x000055af5f5b0f24 ruby`exec_hooks_unprotected(ec=0x000055af60b2b700, list=0x000055af60b2b920, trace_arg=0x00007fff1016d398) at vm_trace.c:333:5 frame #28: 0x000055af5f5b0da8 ruby`rb_exec_event_hooks(trace_arg=0x00007fff1016d398, hooks=0x000055af60b2b920, pop_p=0) at vm_trace.c:378:13 frame #29: 0x000055af5f33f8e2 ruby`rb_exec_event_hook_orig(ec=0x000055af60b2b700, hooks=0x000055af60b2b920, flag=1048576, self=0x00007f7d5b5c08c0, id=0, called_id=0, klass=0x0000000000000000, data=0x00007f7d5b513fd0, pop_p=0) at vm_core.h:1989:5 frame #30: 0x000055af5f334975 ruby`gc_event_hook_body(ec=0x000055af60b2b700, objspace=0x000055af60b2b040, event=1048576, data=0x00007f7d5b513fd0) at gc.c:2083:5 * frame #31: 0x000055af5f3342df ruby`newobj_slowpath_wb_protected [inlined] newobj_slowpath(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, objspace=0x000055af60b2b040, cr=0x000055af60b2b910, wb_protected=1) at gc.c:2284:9 frame #32: 0x000055af5f33410f ruby`newobj_slowpath_wb_protected(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, objspace=0x000055af60b2b040, cr=0x000055af60b2b910) at gc.c:2299 frame #33: 0x000055af5f333de9 ruby`newobj_of0(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, wb_protected=1, cr=0x000055af60b2b910) at gc.c:2338:11 frame #34: 0x000055af5f3227ae ruby`newobj_of(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, v1=0x000055af657d88a0, v2=0x000055af657d8890, v3=0x0000000000000000, wb_protected=1) at gc.c:2348:17 frame #35: 0x000055af5f322c5b ruby`rb_imemo_new(type=imemo_env, v1=0x000055af657d88a0, v2=0x000055af657d8890, v3=0x0000000000000000, v0=0x00007f7d5b9d19c8) at gc.c:2434:12 frame #36: 0x000055af5f5a3925 ruby`vm_env_new(env_ep=0x000055af657d88a0, env_body=0x000055af657d8890, env_size=4, iseq=0x00007f7d5b9d19c8) at vm_core.h:1363:33 frame #37: 0x000055af5f5a3808 ruby`vm_make_env_each(ec=0x000055af60b2b700, cfp=0x00007f7d6482fc90) at vm.c:801:11 frame #38: 0x000055af5f5a368d ruby`vm_make_env_each(ec=0x000055af60b2b700, cfp=0x00007f7d6482fc20) at vm.c:752:13 frame #39: 0x000055af5f5a368d ruby`vm_make_env_each(ec=0x000055af60b2b700, cfp=0x00007f7d6482fbb0) at vm.c:752:13 (lldb) f 31 frame #31: 0x000055af5f3342df ruby`newobj_slowpath_wb_protected [inlined] newobj_slowpath(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, objspace=0x000055af60b2b040, cr=0x000055af60b2b910, wb_protected=1) at gc.c:2284:9 2281 } 2282 GC_ASSERT(obj != 0); 2283 newobj_init(klass, flags, wb_protected, objspace, obj); -> 2284 gc_event_hook_prep(objspace, RUBY_INTERNAL_EVENT_NEWOBJ, obj, newobj_fill(obj, 0, 0, 0)); 2285 } 2286 RB_VM_LOCK_LEAVE_CR_LEV(cr, &lev); 2287 (lldb) p obj (VALUE) $3 = 0x00007f7d5b513fd0 (lldb) f 6 frame #6: 0x000055af5f339b0a ruby`gc_ref_update_imemo(objspace=0x000055af60b2b040, obj=0x00007f7d5b513fd0) at gc.c:9046:13 9043 { 9044 rb_env_t *env = (rb_env_t *)obj; 9045 TYPED_UPDATE_IF_MOVED(objspace, rb_iseq_t *, env->iseq); -> 9046 UPDATE_IF_MOVED(objspace, env->ep[VM_ENV_DATA_INDEX_ENV]); 9047 gc_update_values(objspace, (long)env->env_size, (VALUE *)env->env); 9048 } 9049 break; (lldb) p obj (VALUE) $4 = 0x00007f7d5b513fd0 (lldb) ```

cYjitCodeComment is only defined if we're not in debugging mode

This commit adds a check on the ep just like in the mark function. The env can contain null bytes if allocation tracing is enabled. We're seeing errors during autocompaction like this: ``` (lldb) bt 40 * thread #1, name = 'ruby', stop reason = signal SIGABRT frame #0: 0x00007f7d64b6018b libc.so.6`raise + 203 frame #1: 0x00007f7d64b3f859 libc.so.6`abort + 299 frame #2: 0x000055af5f2fefc9 ruby`die at error.c:764:5 frame #3: 0x000055af5f2ff1ac ruby`rb_bug_for_fatal_signal(default_sighandler=0x0000000000000000, sig=11, ctx=0x000055af60bc3340, fmt="") at error.c:804:5 frame #4: 0x000055af5f4bd08f ruby`sigsegv(sig=11, info=0x000055af60bc3470, ctx=0x000055af60bc3340) at signal.c:960:5 frame #5: 0x00007f7d64ebe3c0 libpthread.so.0`__restore_rt frame #6: 0x000055af5f339b0a ruby`gc_ref_update_imemo(objspace=0x000055af60b2b040, obj=0x00007f7d5b513fd0) at gc.c:9046:13 frame #7: 0x000055af5f339172 ruby`gc_update_object_references(objspace=0x000055af60b2b040, obj=0x00007f7d5b513fd0) at gc.c:9307:9 frame #8: 0x000055af5f338e79 ruby`gc_ref_update(vstart=0x00007f7d5b510010, vend=0x00007f7d5b513ff8, stride=40, objspace=0x000055af60b2b040, page=0x000055af62577aa0) at gc.c:9452:21 frame #9: 0x000055af5f337846 ruby`gc_update_references(objspace=0x000055af60b2b040, heap=0x000055af60b2b068) at gc.c:9481:9 frame #10: 0x000055af5f336569 ruby`gc_compact_finish(objspace=0x000055af60b2b040, heap=0x000055af60b2b068) at gc.c:4840:5 frame #11: 0x000055af5f335efb ruby`gc_page_sweep(objspace=0x000055af60b2b040, heap=0x000055af60b2b068, sweep_page=0x000055af63a1eb30) at gc.c:5046:13 frame #12: 0x000055af5f3355c5 ruby`gc_sweep_step(objspace=0x000055af60b2b040, heap=0x000055af60b2b068) at gc.c:5214:19 frame #13: 0x000055af5f33daf6 ruby`gc_sweep_rest(objspace=0x000055af60b2b040) at gc.c:5271:2 frame #14: 0x000055af5f33cacd ruby`gc_sweep(objspace=0x000055af60b2b040) at gc.c:5389:2 frame #15: 0x000055af5f33c21d ruby`gc_marks_rest(objspace=0x000055af60b2b040) at gc.c:7555:5 frame #16: 0x000055af5f324d41 ruby`gc_rest(objspace=0x000055af60b2b040) at gc.c:8457:13 frame #17: 0x000055af5f3297d8 ruby`garbage_collect(objspace=0x000055af60b2b040, reason=45568) at gc.c:8318:9 frame #18: 0x000055af5f344ece ruby`garbage_collect_with_gvl(objspace=0x000055af60b2b040, reason=45568) at gc.c:8632:9 frame #19: 0x000055af5f344e61 ruby`objspace_malloc_gc_stress(objspace=0x000055af60b2b040) at gc.c:10592:9 frame #20: 0x000055af5f32ced1 ruby`objspace_xmalloc0(objspace=0x000055af60b2b040, size=64) at gc.c:10767:5 frame #21: 0x000055af5f32ce11 ruby`ruby_xmalloc0(size=64) at gc.c:10988:12 frame #22: 0x000055af5f32cdac ruby`ruby_xmalloc_body(size=64) at gc.c:10997:12 frame #23: 0x000055af5f329415 ruby`ruby_xmalloc(size=64) at gc.c:12942:12 frame #24: 0x00007f7d611c4fe5 objspace.so`newobj_i(tpval=0x00007f7d5b553770, data=0x000055af639031a0) at object_tracing.c:101:35 frame #25: 0x000055af5f5b283f ruby`tp_call_trace(tpval=0x00007f7d5b553770, trace_arg=0x00007fff1016d398) at vm_trace.c:1115:2 frame #26: 0x000055af5f5b50ec ruby`exec_hooks_body(ec=0x000055af60b2b700, list=0x000055af60b2b920, trace_arg=0x00007fff1016d398) at vm_trace.c:304:3 frame #27: 0x000055af5f5b0f24 ruby`exec_hooks_unprotected(ec=0x000055af60b2b700, list=0x000055af60b2b920, trace_arg=0x00007fff1016d398) at vm_trace.c:333:5 frame #28: 0x000055af5f5b0da8 ruby`rb_exec_event_hooks(trace_arg=0x00007fff1016d398, hooks=0x000055af60b2b920, pop_p=0) at vm_trace.c:378:13 frame #29: 0x000055af5f33f8e2 ruby`rb_exec_event_hook_orig(ec=0x000055af60b2b700, hooks=0x000055af60b2b920, flag=1048576, self=0x00007f7d5b5c08c0, id=0, called_id=0, klass=0x0000000000000000, data=0x00007f7d5b513fd0, pop_p=0) at vm_core.h:1989:5 frame #30: 0x000055af5f334975 ruby`gc_event_hook_body(ec=0x000055af60b2b700, objspace=0x000055af60b2b040, event=1048576, data=0x00007f7d5b513fd0) at gc.c:2083:5 * frame #31: 0x000055af5f3342df ruby`newobj_slowpath_wb_protected [inlined] newobj_slowpath(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, objspace=0x000055af60b2b040, cr=0x000055af60b2b910, wb_protected=1) at gc.c:2284:9 frame #32: 0x000055af5f33410f ruby`newobj_slowpath_wb_protected(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, objspace=0x000055af60b2b040, cr=0x000055af60b2b910) at gc.c:2299 frame #33: 0x000055af5f333de9 ruby`newobj_of0(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, wb_protected=1, cr=0x000055af60b2b910) at gc.c:2338:11 frame #34: 0x000055af5f3227ae ruby`newobj_of(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, v1=0x000055af657d88a0, v2=0x000055af657d8890, v3=0x0000000000000000, wb_protected=1) at gc.c:2348:17 frame #35: 0x000055af5f322c5b ruby`rb_imemo_new(type=imemo_env, v1=0x000055af657d88a0, v2=0x000055af657d8890, v3=0x0000000000000000, v0=0x00007f7d5b9d19c8) at gc.c:2434:12 frame #36: 0x000055af5f5a3925 ruby`vm_env_new(env_ep=0x000055af657d88a0, env_body=0x000055af657d8890, env_size=4, iseq=0x00007f7d5b9d19c8) at vm_core.h:1363:33 frame #37: 0x000055af5f5a3808 ruby`vm_make_env_each(ec=0x000055af60b2b700, cfp=0x00007f7d6482fc90) at vm.c:801:11 frame #38: 0x000055af5f5a368d ruby`vm_make_env_each(ec=0x000055af60b2b700, cfp=0x00007f7d6482fc20) at vm.c:752:13 frame #39: 0x000055af5f5a368d ruby`vm_make_env_each(ec=0x000055af60b2b700, cfp=0x00007f7d6482fbb0) at vm.c:752:13 (lldb) f 31 frame #31: 0x000055af5f3342df ruby`newobj_slowpath_wb_protected [inlined] newobj_slowpath(klass=0x00007f7d5b9d19c8, flags=0x000000000000001a, objspace=0x000055af60b2b040, cr=0x000055af60b2b910, wb_protected=1) at gc.c:2284:9 2281 } 2282 GC_ASSERT(obj != 0); 2283 newobj_init(klass, flags, wb_protected, objspace, obj); -> 2284 gc_event_hook_prep(objspace, RUBY_INTERNAL_EVENT_NEWOBJ, obj, newobj_fill(obj, 0, 0, 0)); 2285 } 2286 RB_VM_LOCK_LEAVE_CR_LEV(cr, &lev); 2287 (lldb) p obj (VALUE) $3 = 0x00007f7d5b513fd0 (lldb) f 6 frame #6: 0x000055af5f339b0a ruby`gc_ref_update_imemo(objspace=0x000055af60b2b040, obj=0x00007f7d5b513fd0) at gc.c:9046:13 9043 { 9044 rb_env_t *env = (rb_env_t *)obj; 9045 TYPED_UPDATE_IF_MOVED(objspace, rb_iseq_t *, env->iseq); -> 9046 UPDATE_IF_MOVED(objspace, env->ep[VM_ENV_DATA_INDEX_ENV]); 9047 gc_update_values(objspace, (long)env->env_size, (VALUE *)env->env); 9048 } 9049 break; (lldb) p obj (VALUE) $4 = 0x00007f7d5b513fd0 (lldb) ```

Include some basic info on MMTk on crashes

Always look up instance variable buffers when iterating. It is possible for the instance variable buffer to change out from under the object during iteration, so we cannot cache the buffer on the stack. In the case of Bug #19095, the transient heap moved the buffer during iteration: ``` Watchpoint 1 hit: old value: 0x0000000107c00df8 new value: 0x00000001032743c0 Process 31720 stopped * thread #1, queue = 'com.apple.main-thread', stop reason = watchpoint 1 frame #0: 0x00000001006e5178 miniruby`rb_obj_transient_heap_evacuate(obj=0x000000010d6b94b0, promote=1) at variable.c:1361:5 1358 } 1359 MEMCPY(new_ptr, old_ptr, VALUE, len); 1360 ROBJECT(obj)->as.heap.ivptr = new_ptr; -> 1361 } 1362 } 1363 #endif 1364 miniruby`rb_obj_transient_heap_evacuate: -> 0x1006e5178 <+328>: b 0x1006e517c ; <+332> at variable.c:1362:1 0x1006e517c <+332>: ldp x29, x30, [sp, #0x50] 0x1006e5180 <+336>: add sp, sp, #0x60 0x1006e5184 <+340>: ret Target 0: (miniruby) stopped. (lldb) bt * thread #1, queue = 'com.apple.main-thread', stop reason = watchpoint 1 * frame #0: 0x00000001006e5178 miniruby`rb_obj_transient_heap_evacuate(obj=0x000000010d6b94b0, promote=1) at variable.c:1361:5 frame #1: 0x00000001006cb150 miniruby`transient_heap_block_evacuate(theap=0x0000000100b196c0, block=0x0000000107c00000) at transient_heap.c:734:17 frame #2: 0x00000001006c854c miniruby`transient_heap_evacuate(dmy=0x0000000000000000) at transient_heap.c:808:17 frame #3: 0x00000001007fe6c0 miniruby`rb_postponed_job_flush(vm=0x0000000104402900) at vm_trace.c:1773:21 frame #4: 0x0000000100637a84 miniruby`rb_threadptr_execute_interrupts(th=0x0000000103803bc0, blocking_timing=0) at thread.c:2316:13 frame #5: 0x000000010078b730 miniruby`rb_vm_check_ints(ec=0x00000001048038d0) at vm_core.h:2025:9 frame #6: 0x00000001006fbd10 miniruby`vm_pop_frame(ec=0x00000001048038d0, cfp=0x0000000104a04440, ep=0x0000000104904a28) at vm_insnhelper.c:422:5 frame #7: 0x00000001006fbca0 miniruby`rb_vm_pop_frame(ec=0x00000001048038d0) at vm_insnhelper.c:431:5 frame #8: 0x00000001007d6420 miniruby`vm_call0_cfunc_with_frame(ec=0x00000001048038d0, calling=0x000000016fdcc6a0, argv=0x0000000000000000) at vm_eval.c:153:9 frame #9: 0x00000001007d44cc miniruby`vm_call0_cfunc(ec=0x00000001048038d0, calling=0x000000016fdcc6a0, argv=0x0000000000000000) at vm_eval.c:164:12 frame #10: 0x0000000100766e80 miniruby`vm_call0_body(ec=0x00000001048038d0, calling=0x000000016fdcc6a0, argv=0x0000000000000000) at vm_eval.c:210:15 frame #11: 0x00000001007d76f0 miniruby`vm_call0_cc(ec=0x00000001048038d0, recv=0x000000010d6b49d8, id=2769, argc=0, argv=0x0000000000000000, cc=0x000000010d6b2e58, kw_splat=0) at vm_eval.c:87:12 frame #12: 0x0000000100769e48 miniruby`rb_funcallv_scope(recv=0x000000010d6b49d8, mid=2769, argc=0, argv=0x0000000000000000, scope=CALL_FCALL) at vm_eval.c:1051:16 frame #13: 0x0000000100760a54 miniruby`rb_funcallv(recv=0x000000010d6b49d8, mid=2769, argc=0, argv=0x0000000000000000) at vm_eval.c:1066:12 frame #14: 0x000000010037513c miniruby`rb_inspect(obj=0x000000010d6b49d8) at object.c:633:34 frame #15: 0x000000010002c950 miniruby`inspect_ary(ary=0x000000010d6b4938, dummy=0x0000000000000000, recur=0) at array.c:3091:13 frame #16: 0x0000000100642020 miniruby`exec_recursive(func=(miniruby`inspect_ary at array.c:3084), obj=0x000000010d6b4938, pairid=0x0000000000000000, arg=0x0000000000000000, outer=0, mid=2769) at thread.c:5177:23 frame #17: 0x00000001006412fc miniruby`rb_exec_recursive(func=(miniruby`inspect_ary at array.c:3084), obj=0x000000010d6b4938, arg=0x0000000000000000) at thread.c:5205:12 frame #18: 0x00000001000127f0 miniruby`rb_ary_inspect(ary=0x000000010d6b4938) at array.c:3117:12 ``` In general though, any calls back out to the interpreter could change the IV buffer, so it's not safe to cache. [Bug #19095]

[Bug #19793] Dummy frames are created at the top level when requiring another file. While requiring a file, it will try to convert using encodings. Some of these encodings will not respond to to_str. If method_missing is redefined on Object, then it will call method_missing and attempt raise an error. However, the iseq is invalid as it's a dummy frame so it will write an invalid iseq to the created NoMethodError. The following script crashes: ``` GC.stress = true class Object public :method_missing end File.write("/tmp/empty.rb", "") require "/tmp/empty.rb" ``` With the following backtrace: ``` frame #0: 0x00000001000fa8b8 miniruby`RVALUE_MARKED(obj=4308637824) at gc.c:1638:12 frame #1: 0x00000001000fb440 miniruby`RVALUE_BLACK_P(obj=4308637824) at gc.c:1763:12 frame #2: 0x00000001000facdc miniruby`gc_writebarrier_incremental(a=4308637824, b=4308332208, objspace=0x000000010180b000) at gc.c:8822:9 frame #3: 0x00000001000faad8 miniruby`rb_gc_writebarrier(a=4308637824, b=4308332208) at gc.c:8864:17 frame #4: 0x000000010016aff0 miniruby`rb_obj_written(a=4308637824, oldv=36, b=4308332208, filename="../iseq.c", line=1279) at gc.h:804:9 frame #5: 0x0000000100162a60 miniruby`rb_obj_write(a=4308637824, slot=0x0000000100d09888, b=4308332208, filename="../iseq.c", line=1279) at gc.h:837:5 frame #6: 0x0000000100165b0c miniruby`iseqw_new(iseq=0x0000000100d09880) at iseq.c:1279:9 frame #7: 0x0000000100165a64 miniruby`rb_iseqw_new(iseq=0x0000000100d09880) at iseq.c:1289:12 frame #8: 0x00000001000d8324 miniruby`name_err_init_attr(exc=4309777920, recv=4304780496, method=827660) at error.c:1830:35 frame #9: 0x00000001000d1b80 miniruby`name_err_init(exc=4309777920, mesg=4308332496, recv=4304780496, method=827660) at error.c:1869:12 frame #10: 0x00000001000d1bd4 miniruby`rb_nomethod_err_new(mesg=4308332496, recv=4304780496, method=827660, args=4308332448, priv=0) at error.c:1957:5 frame #11: 0x000000010039049c miniruby`rb_make_no_method_exception(exc=4304914512, format=4308332496, obj=4304780496, argc=1, argv=0x000000016fdfab00, priv=0) at vm_eval.c:959:16 frame #12: 0x00000001003b3274 miniruby`raise_method_missing(ec=0x0000000100b06f40, argc=1, argv=0x000000016fdfab00, obj=4304780496, last_call_status=MISSING_NOENTRY) at vm_eval.c:999:15 frame #13: 0x00000001003945d4 miniruby`rb_method_missing(argc=1, argv=0x000000016fdfab00, obj=4304780496) at vm_eval.c:944:5 ... frame #23: 0x000000010038f5e4 miniruby`rb_vm_call_kw(ec=0x0000000100b06f40, recv=4304780496, id=2865, argc=1, argv=0x000000016fdfab00, me=0x0000000100cbfcf0, kw_splat=0) at vm_eval.c:326:12 frame #24: 0x00000001003c18e4 miniruby`call_method_entry(ec=0x0000000100b06f40, defined_class=4304927952, obj=4304780496, id=2865, cme=0x0000000100cbfcf0, argc=1, argv=0x000000016fdfab00, kw_splat=0) at vm_method.c:2720:20 frame #25: 0x00000001003c440c miniruby`check_funcall_exec(v=6171896792) at vm_eval.c:589:12 frame #26: 0x00000001000dec00 miniruby`rb_vrescue2(b_proc=(miniruby`check_funcall_exec at vm_eval.c:587), data1=6171896792, r_proc=(miniruby`check_funcall_failed at vm_eval.c:596), data2=6171896792, args="Pȗ") at eval.c:919:18 frame #27: 0x00000001000deab0 miniruby`rb_rescue2(b_proc=(miniruby`check_funcall_exec at vm_eval.c:587), data1=6171896792, r_proc=(miniruby`check_funcall_failed at vm_eval.c:596), data2=6171896792) at eval.c:900:17 frame #28: 0x000000010039008c miniruby`check_funcall_missing(ec=0x0000000100b06f40, klass=4304923536, recv=4304780496, mid=3233, argc=0, argv=0x0000000000000000, respond=-1, def=36, kw_splat=0) at vm_eval.c:666:15 frame #29: 0x000000010038fa60 miniruby`rb_check_funcall_default_kw(recv=4304780496, mid=3233, argc=0, argv=0x0000000000000000, def=36, kw_splat=0) at vm_eval.c:703:21 frame #30: 0x000000010038fb04 miniruby`rb_check_funcall(recv=4304780496, mid=3233, argc=0, argv=0x0000000000000000) at vm_eval.c:685:12 frame #31: 0x00000001001c469c miniruby`convert_type_with_id(val=4304780496, tname="String", method=3233, raise=0, index=-1) at object.c:3061:15 frame #32: 0x00000001001c4a4c miniruby`rb_check_convert_type_with_id(val=4304780496, type=5, tname="String", method=3233) at object.c:3153:9 frame #33: 0x00000001002d59f8 miniruby`rb_check_string_type(str=4304780496) at string.c:2571:11 frame #34: 0x000000010014b7b0 miniruby`io_encoding_set(fptr=0x0000000100d09ca0, v1=4304780496, v2=4, opt=4) at io.c:11655:19 frame #35: 0x0000000100139a58 miniruby`rb_io_set_encoding(argc=1, argv=0x000000016fdfb450, io=4308334032) at io.c:13497:5 frame #36: 0x00000001003c0004 miniruby`ractor_safe_call_cfunc_m1(recv=4308334032, argc=1, argv=0x000000016fdfb450, func=(miniruby`rb_io_set_encoding at io.c:13487)) at vm_insnhelper.c:3271:12 ... frame #43: 0x0000000100390b08 miniruby`rb_funcall(recv=4308334032, mid=16593, n=1) at vm_eval.c:1137:12 frame #44: 0x00000001002a43d8 miniruby`load_file_internal(argp_v=6171899936) at ruby.c:2500:5 ... ```

Fix crash in NoMethodError for dummy frames MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [Bug #19793] Dummy frames are created at the top level when requiring another file. While requiring a file, it will try to convert using encodings. Some of these encodings will not respond to to_str. If method_missing is redefined on Object, then it will call method_missing and attempt raise an error. However, the iseq is invalid as it's a dummy frame so it will write an invalid iseq to the created NoMethodError. The following script crashes: ``` GC.stress = true class Object public :method_missing end File.write("/tmp/empty.rb", "") require "/tmp/empty.rb" ``` With the following backtrace: ``` frame #0: 0x00000001000fa8b8 miniruby`RVALUE_MARKED(obj=4308637824) at gc.c:1638:12 frame #1: 0x00000001000fb440 miniruby`RVALUE_BLACK_P(obj=4308637824) at gc.c:1763:12 frame #2: 0x00000001000facdc miniruby`gc_writebarrier_incremental(a=4308637824, b=4308332208, objspace=0x000000010180b000) at gc.c:8822:9 frame #3: 0x00000001000faad8 miniruby`rb_gc_writebarrier(a=4308637824, b=4308332208) at gc.c:8864:17 frame #4: 0x000000010016aff0 miniruby`rb_obj_written(a=4308637824, oldv=36, b=4308332208, filename="../iseq.c", line=1279) at gc.h:804:9 frame #5: 0x0000000100162a60 miniruby`rb_obj_write(a=4308637824, slot=0x0000000100d09888, b=4308332208, filename="../iseq.c", line=1279) at gc.h:837:5 frame #6: 0x0000000100165b0c miniruby`iseqw_new(iseq=0x0000000100d09880) at iseq.c:1279:9 frame #7: 0x0000000100165a64 miniruby`rb_iseqw_new(iseq=0x0000000100d09880) at iseq.c:1289:12 frame #8: 0x00000001000d8324 miniruby`name_err_init_attr(exc=4309777920, recv=4304780496, method=827660) at error.c:1830:35 frame #9: 0x00000001000d1b80 miniruby`name_err_init(exc=4309777920, mesg=4308332496, recv=4304780496, method=827660) at error.c:1869:12 frame #10: 0x00000001000d1bd4 miniruby`rb_nomethod_err_new(mesg=4308332496, recv=4304780496, method=827660, args=4308332448, priv=0) at error.c:1957:5 frame #11: 0x000000010039049c miniruby`rb_make_no_method_exception(exc=4304914512, format=4308332496, obj=4304780496, argc=1, argv=0x000000016fdfab00, priv=0) at vm_eval.c:959:16 frame #12: 0x00000001003b3274 miniruby`raise_method_missing(ec=0x0000000100b06f40, argc=1, argv=0x000000016fdfab00, obj=4304780496, last_call_status=MISSING_NOENTRY) at vm_eval.c:999:15 frame #13: 0x00000001003945d4 miniruby`rb_method_missing(argc=1, argv=0x000000016fdfab00, obj=4304780496) at vm_eval.c:944:5 ... frame #23: 0x000000010038f5e4 miniruby`rb_vm_call_kw(ec=0x0000000100b06f40, recv=4304780496, id=2865, argc=1, argv=0x000000016fdfab00, me=0x0000000100cbfcf0, kw_splat=0) at vm_eval.c:326:12 frame #24: 0x00000001003c18e4 miniruby`call_method_entry(ec=0x0000000100b06f40, defined_class=4304927952, obj=4304780496, id=2865, cme=0x0000000100cbfcf0, argc=1, argv=0x000000016fdfab00, kw_splat=0) at vm_method.c:2720:20 frame #25: 0x00000001003c440c miniruby`check_funcall_exec(v=6171896792) at vm_eval.c:589:12 frame #26: 0x00000001000dec00 miniruby`rb_vrescue2(b_proc=(miniruby`check_funcall_exec at vm_eval.c:587), data1=6171896792, r_proc=(miniruby`check_funcall_failed at vm_eval.c:596), data2=6171896792, args="Pȗ") at eval.c:919:18 frame #27: 0x00000001000deab0 miniruby`rb_rescue2(b_proc=(miniruby`check_funcall_exec at vm_eval.c:587), data1=6171896792, r_proc=(miniruby`check_funcall_failed at vm_eval.c:596), data2=6171896792) at eval.c:900:17 frame #28: 0x000000010039008c miniruby`check_funcall_missing(ec=0x0000000100b06f40, klass=4304923536, recv=4304780496, mid=3233, argc=0, argv=0x0000000000000000, respond=-1, def=36, kw_splat=0) at vm_eval.c:666:15 frame #29: 0x000000010038fa60 miniruby`rb_check_funcall_default_kw(recv=4304780496, mid=3233, argc=0, argv=0x0000000000000000, def=36, kw_splat=0) at vm_eval.c:703:21 frame #30: 0x000000010038fb04 miniruby`rb_check_funcall(recv=4304780496, mid=3233, argc=0, argv=0x0000000000000000) at vm_eval.c:685:12 frame #31: 0x00000001001c469c miniruby`convert_type_with_id(val=4304780496, tname="String", method=3233, raise=0, index=-1) at object.c:3061:15 frame #32: 0x00000001001c4a4c miniruby`rb_check_convert_type_with_id(val=4304780496, type=5, tname="String", method=3233) at object.c:3153:9 frame #33: 0x00000001002d59f8 miniruby`rb_check_string_type(str=4304780496) at string.c:2571:11 frame #34: 0x000000010014b7b0 miniruby`io_encoding_set(fptr=0x0000000100d09ca0, v1=4304780496, v2=4, opt=4) at io.c:11655:19 frame #35: 0x0000000100139a58 miniruby`rb_io_set_encoding(argc=1, argv=0x000000016fdfb450, io=4308334032) at io.c:13497:5 frame #36: 0x00000001003c0004 miniruby`ractor_safe_call_cfunc_m1(recv=4308334032, argc=1, argv=0x000000016fdfb450, func=(miniruby`rb_io_set_encoding at io.c:13487)) at vm_insnhelper.c:3271:12 ... frame #43: 0x0000000100390b08 miniruby`rb_funcall(recv=4308334032, mid=16593, n=1) at vm_eval.c:1137:12 frame #44: 0x00000001002a43d8 miniruby`load_file_internal(argp_v=6171899936) at ruby.c:2500:5 ... ``` --- error.c | 4 +++- test/ruby/test_require.rb | 15 +++++++++++++++ 2 files changed, 18 insertions(+), 1 deletion(-)

to avoid deadlock ```ruby r = Ractor.new do obj = Thread.new{} Ractor.yield obj rescue => e e.message end p r.take ``` ``` (lldb) bt * thread #1, name = 'miniruby', stop reason = signal SIGSTOP * frame #0: 0x0000ffff44881410 libpthread.so.0`__lll_lock_wait + 88 frame #1: 0x0000ffff4487a078 libpthread.so.0`__pthread_mutex_lock + 232 frame #2: 0x0000aaab617c0980 miniruby`rb_native_mutex_lock(lock=<unavailable>) at thread_pthread.c:109:14 frame #3: 0x0000aaab617c1d58 miniruby`ubf_event_waiting [inlined] thread_sched_lock_(th=0x0000aaab9df82980, file=<unavailable>, line=46, sched=0x0000aaab9dec79b8) at thread_pthread.c:351:5 frame #4: 0x0000aaab617c1d50 miniruby`ubf_event_waiting(ptr=0x0000aaab9df82980) at thread_pthread_mn.c:46:5 frame #5: 0x0000aaab617c6020 miniruby`rb_threadptr_interrupt [inlined] rb_threadptr_interrupt_common(trap=0, th=0x0000aaab9df82980) at thread.c:352:25 frame #6: 0x0000aaab617c5fec miniruby`rb_threadptr_interrupt(th=0x0000aaab9df82980) at thread.c:365:5 frame #7: 0x0000aaab617379b0 miniruby`rb_ractor_terminate_all at ractor.c:2364:13 frame #8: 0x0000aaab6173797c miniruby`rb_ractor_terminate_all at ractor.c:2383:17 frame #9: 0x0000aaab61737958 miniruby`rb_ractor_terminate_all [inlined] ractor_terminal_interrupt_all(vm=0x0000aaab9dea3320) at ractor.c:2375:1 frame #10: 0x0000aaab61737950 miniruby`rb_ractor_terminate_all at ractor.c:2424:13 frame #11: 0x0000aaab6164f108 miniruby`rb_ec_cleanup(ec=0x0000aaab9dea5900, ex=RUBY_TAG_NONE) at eval.c:239:9 frame #12: 0x0000aaab6164fa3c miniruby`ruby_run_node(n=0x0000ffff417ed178) at eval.c:328:12 frame #13: 0x0000aaab615a5ab0 miniruby`main at main.c:39:12 frame #14: 0x0000aaab615a5a98 miniruby`main(argc=<unavailable>, argv=<unavailable>) at main.c:58:12 frame #15: 0x0000ffff44714b2c libc.so.6`__libc_start_main + 228 frame #16: 0x0000aaab615a5b0c miniruby`_start + 52 (lldb) thread select 3 * thread #3, name = 'bootstraptest.*', stop reason = signal SIGSTOP frame #0: 0x0000ffff448813ec libpthread.so.0`__lll_lock_wait + 52 libpthread.so.0`__lll_lock_wait: -> 0xffff448813ec <+52>: svc #0 0xffff448813f0 <+56>: eor w20, w20, #0x80 0xffff448813f4 <+60>: sxtw x20, w20 0xffff448813f8 <+64>: b 0xffff44881414 ; <+92> (lldb) bt * thread #3, name = 'bootstraptest.*', stop reason = signal SIGSTOP * frame #0: 0x0000ffff448813ec libpthread.so.0`__lll_lock_wait + 52 frame #1: 0x0000ffff4487a078 libpthread.so.0`__pthread_mutex_lock + 232 frame #2: 0x0000aaab617c0980 miniruby`rb_native_mutex_lock(lock=<unavailable>) at thread_pthread.c:109:14 frame #3: 0x0000aaab61823d68 miniruby`rb_vm_lock_enter_body [inlined] vm_lock_enter(no_barrier=false, lev=0x0000ffff215bfbe4, locked=false, vm=0x0000aaab9dea3320, cr=0x0000aaab9dec7890) at vm_sync.c:57:9 frame #4: 0x0000aaab61823d60 miniruby`rb_vm_lock_enter_body(lev=0x0000ffff215bfbe4) at vm_sync.c:119:9 frame #5: 0x0000aaab617c1b30 miniruby`thread_sched_setup_running_threads [inlined] rb_vm_lock_enter(file=<unavailable>, line=597, lev=0x0000ffff215bfbe4) at vm_sync.h:75:9 frame #6: 0x0000aaab617c1b14 miniruby`thread_sched_setup_running_threads(vm=0x0000aaab9dea3320, add_th=0x0000aaab9df82980, del_th=<unavailable>, add_timeslice_th=0x0000000000000000, cr=<unavailable>, sched=<unavailable>, sched=<unavailable>) at thread_pthread.c:597:9 frame #7: 0x0000aaab617c29b4 miniruby`thread_sched_wait_running_turn at thread_pthread.c:614:5 frame #8: 0x0000aaab617c298c miniruby`thread_sched_wait_running_turn(sched=0x0000aaab9dec79b8, th=0x0000aaab9df82980, can_direct_transfer=true) at thread_pthread.c:868:9 frame #9: 0x0000aaab617c6f0c miniruby`thread_sched_wait_events(sched=0x0000aaab9dec79b8, th=0x0000aaab9df82980, fd=<unavailable>, events=<unavailable>, rel=<unavailable>) at thread_pthread_mn.c:90:17 frame #10: 0x0000aaab617c7354 miniruby`rb_thread_terminate_all at thread_pthread.c:3248:13 frame #11: 0x0000aaab617c733c miniruby`rb_thread_terminate_all(th=0x0000aaab9df82980) at thread.c:466:13 frame #12: 0x0000aaab617c7a64 miniruby`thread_start_func_2(th=0x0000aaab9df82980, stack_start=<unavailable>) at thread.c:713:9 frame #13: 0x0000aaab617c7d1c miniruby`co_start [inlined] call_thread_start_func_2(th=0x0000aaab9df82980) at thread_pthread.c:2165:5 frame #14: 0x0000aaab617c7cd0 miniruby`co_start(from=<unavailable>, self=0x0000aaab9df0f760) at thread_pthread_mn.c:421:9 ```

During compilation, we write keyword default values into the iseq, so we should mark it to ensure it does not get GC'd. This might fix issues on ASAN like http://ci.rvm.jp/logfiles/brlog.trunk_asan.20240927-194923 ==805257==ERROR: AddressSanitizer: use-after-poison on address 0x7b7e5e3e2828 at pc 0x5e09ac4822f8 bp 0x7ffde56b0140 sp 0x7ffde56b0138 READ of size 8 at 0x7b7e5e3e2828 thread T0 #0 0x5e09ac4822f7 in RB_BUILTIN_TYPE include/ruby/internal/value_type.h:191:30 #1 0x5e09ac4822f7 in rbimpl_RB_TYPE_P_fastpath include/ruby/internal/value_type.h:352:19 #2 0x5e09ac4822f7 in gc_mark gc/default.c:4488:9 #3 0x5e09ac51011e in rb_iseq_mark_and_move iseq.c:361:17 #4 0x5e09ac4b85c4 in rb_imemo_mark_and_move imemo.c:386:9 #5 0x5e09ac467544 in rb_gc_mark_children gc.c:2508:9 #6 0x5e09ac482c24 in gc_mark_children gc/default.c:4673:5 #7 0x5e09ac482c24 in gc_mark_stacked_objects gc/default.c:4694:9 #8 0x5e09ac482c24 in gc_mark_stacked_objects_all gc/default.c:4732:12 #9 0x5e09ac48c7f9 in gc_marks_rest gc/default.c:5755:9 #10 0x5e09ac48c7f9 in gc_marks gc/default.c:5870:9 #11 0x5e09ac48c7f9 in gc_start gc/default.c:6517:13

Pack struct iter_method_arg (40 -> 32 bytes)

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maximecb closed this Jan 25, 2021

casperisfine pushed a commit that referenced this pull request May 5, 2021

Merge pull request #5 from Shopify/release-mode

37a2ee8

cYjitCodeComment is only defined if we're not in debugging mode

eightbitraptor pushed a commit that referenced this pull request Jul 20, 2022

Merge pull request #5 from mmtk/mmtk-bug

7614cbe

Include some basic info on MMTk on crashes

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Pack struct iter_method_arg (40 -> 32 bytes) #5

Pack struct iter_method_arg (40 -> 32 bytes) #5

methodmissing commented Dec 12, 2019

maximecb commented Jan 25, 2021

Pack struct iter_method_arg (40 -> 32 bytes) #5

Pack struct iter_method_arg (40 -> 32 bytes) #5

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methodmissing commented Dec 12, 2019

maximecb commented Jan 25, 2021