Bug #18500: Fix segfault in `TestArray#test_sample` on s390x.

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.0.3p157 (2021-11-24 revision 3fb7d2cadc) [s390x-linux]
• Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: DONE, 3.1: DONTNEED

[vo.x (Vit Ondruch)]

Building with gcc 12 on Fedora Rawhide s390x, I observe following segfault in test suite:

... snip ...

[ 3104/21226] TestArray#test_sample/builddir/build/BUILD/ruby-3.0.3/test/ruby/test_array.rb:2871: [BUG] Segmentation fault at 0x00000000c04fb000
ruby 3.0.3p157 (2021-11-24 revision 3fb7d2cadc) [s390x-linux]
-- Control frame information -----------------------------------------------
c:0031 p:---- s:0176 e:000175 CFUNC  :srand
c:0030 p:0011 s:0171 e:000170 METHOD /builddir/build/BUILD/ruby-3.0.3/test/ruby/test_array.rb:2871
c:0029 p:0052 s:0165 e:000164 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1283
c:0028 p:0065 s:0159 e:000158 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1330
c:0027 p:0013 s:0150 e:000149 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit/testcase.rb:18
c:0026 p:0077 s:0145 e:000144 BLOCK  /builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:979 [FINISH]
c:0025 p:---- s:0138 e:000137 CFUNC  :map
c:0024 p:0006 s:0134 E:0012c8 BLOCK  /builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:972
c:0023 p:0186 s:0130 E:000ba0 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:999
c:0022 p:0042 s:0118 E:000888 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1136
c:0021 p:0010 s:0111 E:0007a0 BLOCK  /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:627 [FINISH]
c:0020 p:---- s:0105 e:000104 CFUNC  :each
c:0019 p:0054 s:0101 E:001588 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:625
c:0018 p:0008 s:0094 E:001eb8 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:662
c:0017 p:0140 s:0087 E:0011a8 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:908
c:0016 p:0016 s:0074 E:001ca8 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1073
c:0015 p:0005 s:0069 E:000710 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1147
c:0014 p:0006 s:0065 E:000438 BLOCK  /builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1134 [FINISH]
c:0013 p:---- s:0061 e:000060 CFUNC  :each
c:0012 p:0047 s:0057 E:0022b8 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1133
c:0011 p:0013 s:0052 E:000288 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1121
c:0010 p:0008 s:0047 E:000c70 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:847
c:0009 p:0008 s:0041 E:0008d0 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:695
c:0008 p:0015 s:0035 E:001f08 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:34
c:0007 p:0006 s:0030 E:0003c8 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1175
c:0006 p:0032 s:0025 E:000e80 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1245
c:0005 p:0009 s:0021 E:0018b8 METHOD /builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1249
c:0004 p:0172 s:0016 E:0001b8 TOP    /builddir/build/BUILD/ruby-3.0.3/tool/test/runner.rb:23 [FINISH]
c:0003 p:---- s:0011 e:000010 CFUNC  :require_relative
c:0002 p:0092 s:0006 E:001bf0 EVAL   ./test/runner.rb:11 [FINISH]
c:0001 p:0000 s:0003 E:0004f0 (none) [FINISH]
-- Ruby level backtrace information ----------------------------------------
./test/runner.rb:11:in `<main>'
./test/runner.rb:11:in `require_relative'
/builddir/build/BUILD/ruby-3.0.3/tool/test/runner.rb:23:in `<top (required)>'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1249:in `run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1245:in `run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1175:in `run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:34:in `run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:695:in `run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:847:in `run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1121:in `run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1133:in `_run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1133:in `each'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1134:in `block in _run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1147:in `run_tests'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1073:in `_run_anything'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:908:in `_run_anything'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:662:in `_run_suites'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:625:in `_run_suites'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:625:in `each'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:627:in `block in _run_suites'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1136:in `_run_suite'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:999:in `_run_suite'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:972:in `block in _run_suite'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:972:in `map'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:979:in `block (2 levels) in _run_suite'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit/testcase.rb:18:in `run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/minitest/unit.rb:1330:in `run'
/builddir/build/BUILD/ruby-3.0.3/tool/lib/test/unit.rb:1283:in `run_test'
/builddir/build/BUILD/ruby-3.0.3/test/ruby/test_array.rb:2871:in `test_sample'
/builddir/build/BUILD/ruby-3.0.3/test/ruby/test_array.rb:2871:in `srand'
-- C level backtrace information -------------------------------------------
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_print_backtrace+0x1c) [0x3ffab964c5c] vm_dump.c:758
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_vm_bugreport.constprop.0+0x4ba) [0x3ffab977f0a] vm_dump.c:998
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_bug_for_fatal_signal+0xb2) [0x3ffab7b2252] error.c:786
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(sigsegv+0x58) [0x3ffab8d2fb8] signal.c:963
[0x3ffabb7e490]
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_free_tmp_buffer+0x4) [0x3ffab7d1114] gc.c:11047
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rand_init+0x122) [0x3ffab896892] random.c:387
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_f_srand+0x6e) [0x3ffab8975fe] random.c:873
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_call_cfunc_with_frame+0x170) [0x3ffab9421f0] vm_insnhelper.c:2931
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_sendish+0x53a) [0x3ffab94659a] vm_insnhelper.c:4532
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_exec_core.lto_priv.0+0xe6) [0x3ffab947d16] insns.def:789
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_vm_exec+0x1ee) [0x3ffab96129e] vm.c:2172
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_yield+0xaa) [0x3ffab951a6a] vm.c:1398
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_ary_collect.lto_priv.0+0x6a) [0x3ffab742d6a] array.c:3635
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_call_cfunc_with_frame+0x170) [0x3ffab9421f0] vm_insnhelper.c:2931
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_sendish+0x53a) [0x3ffab94659a] vm_insnhelper.c:4532
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_exec_core.lto_priv.0+0x21c0) [0x3ffab949df0] insns.def:770
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_vm_exec+0x1ee) [0x3ffab96129e] vm.c:2172
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_yield+0xaa) [0x3ffab951a6a] vm.c:1398
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_ary_each+0x4c) [0x3ffab742aac] array.c:2523
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_call_cfunc_with_frame+0x170) [0x3ffab9421f0] vm_insnhelper.c:2931
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_call_method_each_type+0x530) [0x3ffab942d20] vm_insnhelper.c:3400
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_sendish+0x53a) [0x3ffab94659a] vm_insnhelper.c:4532
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_exec_core.lto_priv.0+0x21c0) [0x3ffab949df0] insns.def:770
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_vm_exec+0x1ee) [0x3ffab96129e] vm.c:2172
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_yield+0xaa) [0x3ffab951a6a] vm.c:1398
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_ary_each+0x4c) [0x3ffab742aac] array.c:2523
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_call_cfunc_with_frame+0x170) [0x3ffab9421f0] vm_insnhelper.c:2931
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_call_method_each_type+0x530) [0x3ffab942d20] vm_insnhelper.c:3400
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_sendish+0x53a) [0x3ffab94659a] vm_insnhelper.c:4532
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_exec_core.lto_priv.0+0x21c0) [0x3ffab949df0] insns.def:770
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_vm_exec+0x1ee) [0x3ffab96129e] vm.c:2172
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(require_internal.lto_priv.0+0xbc6) [0x3ffab809be6] load.c:1109
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_require_string+0x48) [0x3ffab809db8] load.c:1186
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_call_cfunc_with_frame+0x170) [0x3ffab9421f0] vm_insnhelper.c:2931
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_sendish+0x53a) [0x3ffab94659a] vm_insnhelper.c:4532
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(vm_exec_core.lto_priv.0+0xe6) [0x3ffab947d16] insns.def:789
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_vm_exec+0x1ee) [0x3ffab96129e] vm.c:2172
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(rb_ec_exec_node+0x10c) [0x3ffab7b71ac] eval.c:317
/builddir/build/BUILD/ruby-3.0.3/libruby.so.3.0.3(ruby_run_node+0x70) [0x3ffab7b72c0] eval.c:375
[0x2aa26e811f0]
[0x3ffab4b3872]
[0x3ffab4b3950]
[0x2aa26e81250]

... snip ...

Looking around, there is this git|bcc2bb28b04054106f4a36e8fd69b2af6ecb033a in Ruby 3.1 (yes, Ruby 3.1 passes the test case just fine). Trying the patch in Ruby 3.0, it seems to fix the issue.

[vo.x (Vit Ondruch)]

• Status changed from Open to Closed

[vo.x (Vit Ondruch)]

I should also mention that the test case was passing just fine using gcc 11

[vo.x (Vit Ondruch)]

Snippet provided by @sharkcz:

Breakpoint 4, rand_init (rng=rng@entry=0x3fffdf15318 <random_mt_if>, rnd=rnd@entry=0x2aa00632eb0, seed=seed@entry=1) at random.c:365
365	{
(gdb) n
367	    VALUE buf0 = 0;
(gdb) 
371	    len = rb_absint_numwords(seed, 32, NULL);
(gdb) p rb_absint_numwords(seed, 32, 0)
$10 = 0
(gdb) cont
Continuing.

Program received signal SIGSEGV, Segmentation fault.
0x000003fffdc51114 in rb_free_tmp_buffer (store=0xffffc8e0) at gc.c:11047
11047	    rb_imemo_tmpbuf_t *s = (rb_imemo_tmpbuf_t*)ATOMIC_VALUE_EXCHANGE(*store, 0);
(gdb) 

[vo.x (Vit Ondruch)]

If it helps, I have applied this patch in Fedora to fix this issue.

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: REQUIRED, 3.1: DONTNEED to 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: DONE, 3.1: DONTNEED

ruby_3_0 bac99c5175bf58815846f9987093a6d944d07fd3 merged revision(s) bcc2bb28b04054106f4a36e8fd69b2af6ecb033a.