Created attachment 230792 [details] Example source code Compile the attached truss-crash.c with cc -pthread -o truss-crash truss-crash.c and then run ./truss-crash in one shell. In another shell, find the pid of the running truss-crash and attach truss to it: truss -H -o /dev/null -p $pid After a while, interrupt the truss with Ctrl+C. Sometimes, truss-crash will crash with Trace/BPT trap (core dumped). This happens 100% of the time in a VM with 2 cores. GDB shows the following for the core file: GNU gdb (GDB) 11.1 [GDB v11.1 for FreeBSD] Copyright (C) 2021 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-portbld-freebsd12.2". Type "show configuration" for configuration details. For bug reporting instructions, please see: <https://www.gnu.org/software/gdb/bugs/>. Find the GDB manual and other documentation resources online at: <http://www.gnu.org/software/gdb/documentation/>. For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from truss-crash... [New LWP 102187] [New LWP 100569] [New LWP 100816] [New LWP 100817] [New LWP 100820] [New LWP 100827] [New LWP 100829] [New LWP 100830] [New LWP 100940] [New LWP 101209] [New LWP 101287] [New LWP 101288] [New LWP 101289] [New LWP 101290] [New LWP 101291] [New LWP 101292] [New LWP 101293] [New LWP 101294] [New LWP 101297] [New LWP 101299] [New LWP 101300] [New LWP 101301] [New LWP 101302] [New LWP 101303] [New LWP 101304] [New LWP 101307] [New LWP 101308] [New LWP 101312] [New LWP 101314] [New LWP 101315] [New LWP 101316] [New LWP 101320] [New LWP 101321] [New LWP 101322] [New LWP 101323] [New LWP 101324] [New LWP 101325] [New LWP 101326] [New LWP 101327] [New LWP 101328] [New LWP 101332] [New LWP 101333] [New LWP 101334] [New LWP 101335] [New LWP 101336] [New LWP 101337] [New LWP 101338] [New LWP 101339] [New LWP 101340] [New LWP 101341] [New LWP 101342] [New LWP 101343] [New LWP 101344] [New LWP 101345] [New LWP 101346] [New LWP 101347] [New LWP 101350] [New LWP 101351] [New LWP 101352] [New LWP 101353] [New LWP 101355] [New LWP 101357] [New LWP 101358] [New LWP 101359] [New LWP 101360] [New LWP 101366] [New LWP 101373] [New LWP 101374] [New LWP 101375] [New LWP 101376] [New LWP 101379] [New LWP 101385] [New LWP 101386] [New LWP 101387] [New LWP 101388] [New LWP 101389] [New LWP 101390] [New LWP 101391] [New LWP 101392] [New LWP 101393] [New LWP 101394] [New LWP 101395] [New LWP 101396] [New LWP 101397] [New LWP 101398] [New LWP 101399] [New LWP 101400] [New LWP 101401] [New LWP 101402] [New LWP 101403] [New LWP 101404] [New LWP 101405] [New LWP 101406] [New LWP 101407] [New LWP 101533] [New LWP 101591] [New LWP 101712] [New LWP 101713] [New LWP 101887] [New LWP 101892] [New LWP 101901] Core was generated by `truss-crash'. Program terminated with signal SIGTRAP, Trace/breakpoint trap. #0 _umtx_op_err () at /usr/src/lib/libthr/arch/amd64/amd64/_umtx_op_err.S:37 37 RSYSCALL_ERR(_umtx_op) [Current thread is 1 (LWP 102187)] gdb> disass $pc Dump of assembler code for function _umtx_op_err: 0x0000000800269680 <+0>: mov $0x1c6,%rax 0x0000000800269687 <+7>: mov %rcx,%r10 0x000000080026968a <+10>: syscall => 0x000000080026968c <+12>: ret 0x000000080026968d <+13>: int3 0x000000080026968e <+14>: int3 0x000000080026968f <+15>: int3 End of assembler dump. gdb> bt #0 _umtx_op_err () at /usr/src/lib/libthr/arch/amd64/amd64/_umtx_op_err.S:37 #1 0x0000000800265591 in join_common (pthread=0x800680500, thread_return=0x0, abstime=0x0, peek=<optimized out>) at /usr/src/lib/libthr/thread/thr_join.c:147 #2 0x0000000000201afa in main () gdb> i threads Id Target Id Frame * 1 LWP 102187 _umtx_op_err () at /usr/src/lib/libthr/arch/amd64/amd64/_umtx_op_err.S:37 2 LWP 100569 0x0000000000201a28 in func () 3 LWP 100816 0x0000000000201a36 in func () 4 LWP 100817 0x0000000000201a28 in func () 5 LWP 100820 0x0000000000201a36 in func () 6 LWP 100827 0x0000000000201a36 in func () 7 LWP 100829 0x0000000000201a36 in func () 8 LWP 100830 0x0000000000201a28 in func () 9 LWP 100940 0x0000000000201a13 in func () 10 LWP 101209 0x0000000000201a36 in func () 11 LWP 101287 0x0000000000201a28 in func () 12 LWP 101288 0x0000000000201a36 in func () 13 LWP 101289 0x0000000000201a13 in func () 14 LWP 101290 0x0000000000201a36 in func () 15 LWP 101291 0x0000000000201a36 in func () 16 LWP 101292 0x0000000000201a36 in func () 17 LWP 101293 0x0000000000201a36 in func () 18 LWP 101294 0x0000000000201a1a in func () 19 LWP 101297 0x0000000000201a36 in func () 20 LWP 101299 0x0000000000201a28 in func () 21 LWP 101300 0x0000000000201a36 in func () 22 LWP 101301 0x0000000000201a36 in func () 23 LWP 101302 0x0000000000201a28 in func () 24 LWP 101303 0x0000000000201a36 in func () 25 LWP 101304 0x0000000000201a20 in func () 26 LWP 101307 0x0000000000201a36 in func () 27 LWP 101308 0x0000000000201a36 in func () 28 LWP 101312 0x0000000000201a28 in func () 29 LWP 101314 0x0000000000201a39 in func () 30 LWP 101315 0x0000000000201a2e in func () 31 LWP 101316 0x0000000000201a39 in func () 32 LWP 101320 0x0000000000201a36 in func () 33 LWP 101321 0x0000000000201a28 in func () 34 LWP 101322 0x0000000000201a28 in func () 35 LWP 101323 0x0000000000201a36 in func () 36 LWP 101324 0x0000000000201a36 in func () 37 LWP 101325 0x0000000000201a13 in func () 38 LWP 101326 0x0000000000201a1a in func () 39 LWP 101327 0x0000000000201a36 in func () 40 LWP 101328 0x0000000000201a36 in func () 41 LWP 101332 0x0000000000201a36 in func () 42 LWP 101333 0x0000000000201a28 in func () 43 LWP 101334 0x0000000000201a20 in func () 44 LWP 101335 0x0000000000201a28 in func () 45 LWP 101336 0x0000000000201a28 in func () 46 LWP 101337 0x0000000000201a36 in func () 47 LWP 101338 0x0000000000201a36 in func () 48 LWP 101339 0x0000000000201a36 in func () 49 LWP 101340 0x0000000000201a20 in func () 50 LWP 101341 0x0000000000201a36 in func () 51 LWP 101342 0x0000000000201a1a in func () 52 LWP 101343 0x0000000000201a1a in func () 53 LWP 101344 0x0000000000201a28 in func () 54 LWP 101345 0x0000000000201a28 in func () 55 LWP 101346 0x0000000000201a39 in func () 56 LWP 101347 0x0000000000201a28 in func () 57 LWP 101350 0x0000000000201a1a in func () 58 LWP 101351 0x0000000000201a36 in func () 59 LWP 101352 0x0000000000201a36 in func () 60 LWP 101353 0x0000000000201a28 in func () 61 LWP 101355 0x0000000000201a36 in func () 62 LWP 101357 0x0000000000201a36 in func () 63 LWP 101358 0x0000000000201a28 in func () 64 LWP 101359 0x0000000000201a28 in func () 65 LWP 101360 0x0000000000201a28 in func () 66 LWP 101366 0x0000000000201a13 in func () 67 LWP 101373 0x0000000000201a36 in func () 68 LWP 101374 0x0000000000201a36 in func () 69 LWP 101375 0x0000000000201a20 in func () 70 LWP 101376 0x0000000000201a28 in func () 71 LWP 101379 0x0000000000201a28 in func () 72 LWP 101385 0x0000000000201a28 in func () 73 LWP 101386 0x0000000000201a39 in func () 74 LWP 101387 0x0000000000201a28 in func () 75 LWP 101388 0x0000000000201a28 in func () 76 LWP 101389 0x0000000000201a28 in func () 77 LWP 101390 0x0000000000201a3f in func () 78 LWP 101391 0x0000000000201a1a in func () 79 LWP 101392 0x0000000000201a36 in func () 80 LWP 101393 0x0000000000201a36 in func () 81 LWP 101394 0x0000000000201a36 in func () 82 LWP 101395 0x0000000000201a20 in func () 83 LWP 101396 0x0000000000201a20 in func () 84 LWP 101397 0x0000000000201a28 in func () 85 LWP 101398 0x0000000000201a36 in func () 86 LWP 101399 0x0000000000201a36 in func () 87 LWP 101400 0x0000000000201a39 in func () 88 LWP 101401 0x0000000000201a36 in func () 89 LWP 101402 0x0000000000201a28 in func () 90 LWP 101403 0x0000000000201a36 in func () 91 LWP 101404 0x0000000000201a28 in func () 92 LWP 101405 0x0000000000201a28 in func () 93 LWP 101406 0x0000000000201a28 in func () 94 LWP 101407 0x0000000000201a36 in func () 95 LWP 101533 0x0000000000201a36 in func () 96 LWP 101591 0x0000000000201a1a in func () 97 LWP 101712 0x0000000000201a28 in func () 98 LWP 101713 0x0000000000201a36 in func () 99 LWP 101887 0x0000000000201a36 in func () 100 LWP 101892 0x0000000000201a28 in func () 101 LWP 101901 0x0000000000201a13 in func () gdb>
https://reviews.freebsd.org/D33787
A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=a24afbb4e633f6725dfe3de099b8e2a4f6b1b631 commit a24afbb4e633f6725dfe3de099b8e2a4f6b1b631 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2022-01-08 09:46:45 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2022-01-12 05:33:30 +0000 Ignore debugger-injected signals left after detaching PR: 261010 Reported by: Martin Simmons <martin@lispworks.com> Reviewed by: markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D33787 sys/kern/kern_sig.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
A commit in branch stable/13 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=a5f69859956049b5153b0e1b67f8f4a99622dc6f commit a5f69859956049b5153b0e1b67f8f4a99622dc6f Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2022-01-08 09:46:45 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2022-01-15 12:55:32 +0000 Ignore debugger-injected signals left after detaching PR: 261010 (cherry picked from commit a24afbb4e633f6725dfe3de099b8e2a4f6b1b631) sys/kern/kern_sig.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)