Target sim crashes when recording for reverse debugging; find_inferior_ptid returns null

Sat May 16 12:56:20 GMT 2020

../../iron-toolchain/binutils/gdb/process-stratum-target.c:47:
internal-error: virtual gdbarch*
process_stratum_target::thread_architecture(ptid_t): Assertion `inf !=
NULL' failed.

Above is the crash that occur after issuing following gdb commands:
target sim
load
record
si

The crash occurs because find_inferior_ptid() returns NULL.
>From below backtrace, is it possible to determine what could be the
cause of find_inferior_ptid() returning NULL ?

(gdb) record
(gdb) si

Thread 1 "iron-elf-gdb" hit Breakpoint 1,
process_stratum_target::thread_architecture (this=<optimized out>,
ptid=...) at ../../iron-toolchain/binutils/gdb/process-stratum-target.c:47
47        gdb_assert (inf != NULL);
=> 0x00005555557cd709
<process_stratum_target::thread_architecture(ptid_t)+25>: 48 83 c4 20
   add    $0x20,%rsp
   0x00005555557cd70d
<process_stratum_target::thread_architecture(ptid_t)+29>: 48 85 c0
   test   %rax,%rax
   0x00005555557cd710
<process_stratum_target::thread_architecture(ptid_t)+32>: 74 0c   je
  0x5555557cd71e
<process_stratum_target::thread_architecture(ptid_t)+46>
(gdb) p inf
$2 = (inferior *) 0x555555cc3d90
(gdb) bt
#0  process_stratum_target::thread_architecture (this=<optimized out>,
ptid=...) at ../../iron-toolchain/binutils/gdb/process-stratum-target.c:47
#1  0x00005555557df091 in record_full_target::resume
(this=0x555555bc8fb0 <record_full_ops>, ptid=..., step=0,
signal=GDB_SIGNAL_0) at
../../iron-toolchain/binutils/gdb/record-full.c:1078
#2  0x0000555555865670 in target_resume (ptid=..., step=0,
signal=GDB_SIGNAL_0) at
../../iron-toolchain/binutils/gdb/target.h:1326
#3  0x00005555557531ab in do_target_resume (resume_ptid=..., step=0,
sig=GDB_SIGNAL_0) at ../../iron-toolchain/binutils/gdb/infrun.c:2264
#4  0x000055555575af02 in resume_1 (sig=GDB_SIGNAL_0) at
../../iron-toolchain/binutils/gdb/infrun.c:2653
#5  resume (sig=GDB_SIGNAL_0) at ../../iron-toolchain/binutils/gdb/infrun.c:2666
#6  0x000055555575bca0 in keep_going_pass_signal (ecs=0x7fffffffd870)
at ../../iron-toolchain/binutils/gdb/infrun.c:8044
#7  0x000055555575bfd1 in start_step_over () at
../../iron-toolchain/binutils/gdb/infrun.c:2049
#8  0x0000555555761f1e in proceed
(addr=addr@entry=18446744073709551615,
siggnal=siggnal@entry=GDB_SIGNAL_DEFAULT) at
../../iron-toolchain/binutils/gdb/infrun.c:3130
#9  0x000055555574b091 in step_1 (skip_subroutines=0,
single_inst=<optimized out>, count_string=<optimized out>) at
../../iron-toolchain/binutils/gdb/infcmd.c:1047
#10 0x000055555566125a in cmd_func (cmd=<optimized out>,
args=<optimized out>, from_tty=<optimized out>) at
../../iron-toolchain/binutils/gdb/cli/cli-decode.c:2004
#11 0x0000555555880073 in execute_command (p=<optimized out>,
p@entry=0x555555e2ec70 "si", from_tty=1) at
../../iron-toolchain/binutils/gdb/top.c:655
#12 0x000055555570c755 in command_handler (command=0x555555e2ec70
"si") at ../../iron-toolchain/binutils/gdb/event-top.c:588
#13 0x000055555570d631 in command_line_handler (rl=...) at
../../iron-toolchain/binutils/gdb/event-top.c:773
#14 0x000055555570cfcc in gdb_rl_callback_handler (rl=0x555555ccfb60
"si") at /usr/include/c++/9/bits/unique_ptr.h:153
#15 0x000055555590ffe8 in rl_callback_read_char () at
../../../iron-toolchain/binutils/readline/readline/callback.c:281
#16 0x000055555570c276 in gdb_rl_callback_read_char_wrapper_noexcept
() at ../../iron-toolchain/binutils/gdb/event-top.c:177
#17 0x000055555570ce85 in gdb_rl_callback_read_char_wrapper
(client_data=<optimized out>) at
../../iron-toolchain/binutils/gdb/event-top.c:193
#18 0x000055555570c198 in stdin_event_handler (error=<optimized out>,
client_data=0x555555c087e0) at
../../iron-toolchain/binutils/gdb/event-top.c:516
#19 0x0000555555993226 in gdb_wait_for_event (block=block@entry=1) at
../../iron-toolchain/binutils/gdbsupport/event-loop.cc:673
#20 0x000055555599349b in gdb_wait_for_event (block=1) at
../../iron-toolchain/binutils/gdbsupport/event-loop.cc:569
#21 gdb_do_one_event () at
../../iron-toolchain/binutils/gdbsupport/event-loop.cc:215
#22 0x00005555557856a5 in start_event_loop () at
../../iron-toolchain/binutils/gdb/main.c:356
#23 captured_command_loop () at ../../iron-toolchain/binutils/gdb/main.c:416
#24 0x00005555557875e5 in captured_main (data=<optimized out>) at
../../iron-toolchain/binutils/gdb/main.c:1254
#25 gdb_main (args=<optimized out>) at
../../iron-toolchain/binutils/gdb/main.c:1269
#26 0x00005555555da2b0 in main (argc=<optimized out>, argv=<optimized
out>) at ../../iron-toolchain/binutils/gdb/gdb.c:32
(gdb) c
Continuing.
iron-gdb: iron_process_record: addr == 0x1f448

Thread 1 "iron-elf-gdb" hit Breakpoint 1,
process_stratum_target::thread_architecture (this=<optimized out>,
ptid=...) at ../../iron-toolchain/binutils/gdb/process-stratum-target.c:47
47        gdb_assert (inf != NULL);
=> 0x00005555557cd709
<process_stratum_target::thread_architecture(ptid_t)+25>: 48 83 c4 20
   add    $0x20,%rsp
   0x00005555557cd70d
<process_stratum_target::thread_architecture(ptid_t)+29>: 48 85 c0
   test   %rax,%rax
   0x00005555557cd710
<process_stratum_target::thread_architecture(ptid_t)+32>: 74 0c   je
  0x5555557cd71e
<process_stratum_target::thread_architecture(ptid_t)+46>
(gdb) p inf
$3 = (inferior *) 0x555555cc3d90
(gdb) bt
#0  process_stratum_target::thread_architecture (this=<optimized out>,
ptid=...) at ../../iron-toolchain/binutils/gdb/process-stratum-target.c:47
#1  0x00005555557e56e3 in get_thread_regcache (target=0x555555bc9060
<gdbsim_ops>, ptid=...) at
../../iron-toolchain/binutils/gdb/regcache.c:373
#2  0x00005555557e57c4 in get_thread_regcache (thread=<optimized out>)
at ../../iron-toolchain/binutils/gdb/target.h:1323
#3  0x000055555575e507 in handle_signal_stop (ecs=0x7fffffffde10) at
../../iron-toolchain/binutils/gdb/infrun.c:5874
#4  0x000055555576061c in handle_inferior_event (ecs=<optimized out>)
at ../../iron-toolchain/binutils/gdb/infrun.c:5585
#5  0x00005555557615bd in fetch_inferior_event (client_data=<optimized
out>) at ../../iron-toolchain/binutils/gdb/infrun.c:4027
#6  0x000055555560b43a in check_async_event_handlers () at
../../iron-toolchain/binutils/gdb/async-event.c:295
#7  0x000055555599345b in gdb_do_one_event () at
../../iron-toolchain/binutils/gdbsupport/event-loop.cc:194
#8  0x00005555557856a5 in start_event_loop () at
../../iron-toolchain/binutils/gdb/main.c:356
#9  captured_command_loop () at ../../iron-toolchain/binutils/gdb/main.c:416
#10 0x00005555557875e5 in captured_main (data=<optimized out>) at
../../iron-toolchain/binutils/gdb/main.c:1254
#11 gdb_main (args=<optimized out>) at
../../iron-toolchain/binutils/gdb/main.c:1269
#12 0x00005555555da2b0 in main (argc=<optimized out>, argv=<optimized
out>) at ../../iron-toolchain/binutils/gdb/gdb.c:32
(gdb) c
Continuing.
0x0001f44a      713             struct task_struct *tsk = current;
=> 0x0001f44a <do_exit+14>:     f6 51   ld32 %5, %1
   0x0001f44c <do_exit+16>:     82 44   li8 %4, 0x24 # 36
   0x0001f44e <do_exit+18>:     b8 40   add %4, %sp
   0x0001f450 <do_exit+20>:     f2 54   st32 %5, %4
(gdb) si

Thread 1 "iron-elf-gdb" hit Breakpoint 1,
process_stratum_target::thread_architecture (this=<optimized out>,
ptid=...) at ../../iron-toolchain/binutils/gdb/process-stratum-target.c:47
47        gdb_assert (inf != NULL);
=> 0x00005555557cd709
<process_stratum_target::thread_architecture(ptid_t)+25>: 48 83 c4 20
   add    $0x20,%rsp
   0x00005555557cd70d
<process_stratum_target::thread_architecture(ptid_t)+29>: 48 85 c0
   test   %rax,%rax
   0x00005555557cd710
<process_stratum_target::thread_architecture(ptid_t)+32>: 74 0c   je
  0x5555557cd71e
<process_stratum_target::thread_architecture(ptid_t)+46>
(gdb) p inf
$4 = (inferior *) 0x0
(gdb) bt
#0  process_stratum_target::thread_architecture (this=<optimized out>,
ptid=...) at ../../iron-toolchain/binutils/gdb/process-stratum-target.c:47
#1  0x00005555557df091 in record_full_target::resume
(this=0x555555bc8fb0 <record_full_ops>, ptid=..., step=0,
signal=GDB_SIGNAL_0) at
../../iron-toolchain/binutils/gdb/record-full.c:1078
#2  0x0000555555865670 in target_resume (ptid=..., step=0,
signal=GDB_SIGNAL_0) at
../../iron-toolchain/binutils/gdb/target.h:1326
#3  0x00005555557531ab in do_target_resume (resume_ptid=..., step=0,
sig=GDB_SIGNAL_0) at ../../iron-toolchain/binutils/gdb/infrun.c:2264
#4  0x000055555575af02 in resume_1 (sig=GDB_SIGNAL_0) at
../../iron-toolchain/binutils/gdb/infrun.c:2653
#5  resume (sig=GDB_SIGNAL_0) at ../../iron-toolchain/binutils/gdb/infrun.c:2666
#6  0x000055555575bca0 in keep_going_pass_signal (ecs=0x7fffffffdac0)
at ../../iron-toolchain/binutils/gdb/infrun.c:8044
#7  0x000055555576254b in proceed
(addr=addr@entry=18446744073709551615,
siggnal=siggnal@entry=GDB_SIGNAL_DEFAULT) at
../../iron-toolchain/binutils/gdb/infrun.c:3198
#8  0x000055555574b091 in step_1 (skip_subroutines=0,
single_inst=<optimized out>, count_string=<optimized out>) at
../../iron-toolchain/binutils/gdb/infcmd.c:1047
#9  0x000055555566125a in cmd_func (cmd=<optimized out>,
args=<optimized out>, from_tty=<optimized out>) at
../../iron-toolchain/binutils/gdb/cli/cli-decode.c:2004
#10 0x0000555555880073 in execute_command (p=<optimized out>,
p@entry=0x5555560cdcd0 "si", from_tty=1) at
../../iron-toolchain/binutils/gdb/top.c:655
#11 0x000055555570c755 in command_handler (command=0x5555560cdcd0
"si") at ../../iron-toolchain/binutils/gdb/event-top.c:588
#12 0x000055555570d631 in command_line_handler (rl=...) at
../../iron-toolchain/binutils/gdb/event-top.c:773
#13 0x000055555570cfcc in gdb_rl_callback_handler (rl=0x5555560ca130
"si") at /usr/include/c++/9/bits/unique_ptr.h:153
#14 0x000055555590ffe8 in rl_callback_read_char () at
../../../iron-toolchain/binutils/readline/readline/callback.c:281
#15 0x000055555570c276 in gdb_rl_callback_read_char_wrapper_noexcept
() at ../../iron-toolchain/binutils/gdb/event-top.c:177
#16 0x000055555570ce85 in gdb_rl_callback_read_char_wrapper
(client_data=<optimized out>) at
../../iron-toolchain/binutils/gdb/event-top.c:193
#17 0x000055555570c198 in stdin_event_handler (error=<optimized out>,
client_data=0x555555c087e0) at
../../iron-toolchain/binutils/gdb/event-top.c:516
#18 0x0000555555993226 in gdb_wait_for_event (block=block@entry=1) at
../../iron-toolchain/binutils/gdbsupport/event-loop.cc:673
#19 0x000055555599349b in gdb_wait_for_event (block=1) at
../../iron-toolchain/binutils/gdbsupport/event-loop.cc:569
#20 gdb_do_one_event () at
../../iron-toolchain/binutils/gdbsupport/event-loop.cc:215
#21 0x00005555557856a5 in start_event_loop () at
../../iron-toolchain/binutils/gdb/main.c:356
#22 captured_command_loop () at ../../iron-toolchain/binutils/gdb/main.c:416
#23 0x00005555557875e5 in captured_main (data=<optimized out>) at
../../iron-toolchain/binutils/gdb/main.c:1254
#24 gdb_main (args=<optimized out>) at
../../iron-toolchain/binutils/gdb/main.c:1269
#25 0x00005555555da2b0 in main (argc=<optimized out>, argv=<optimized
out>) at ../../iron-toolchain/binutils/gdb/gdb.c:32
(gdb) c
Continuing.
../../iron-toolchain/binutils/gdb/process-stratum-target.c:47:
internal-error: virtual gdbarch*
process_stratum_target::thread_architecture(ptid_t): Assertion `inf !=
NULL' failed.