Hi,

I'm porting mongoc/libbson on AIX (v6.1). First port.

I've started with version 1.9.3. I've just moved to version 1.9.4 .

The "make check" generates crashes (core) for libbson and mongoc, both with -O2 and -g, both in 32bit and 64bit (however, crashes are different).

"make check" makes use of the "--no-fork" option. When not using this option, mongoc shows only 6 FAILures, no crash/core, and libbson is OK.

I've tried with libbson bundled or not inside mongoc: nearly the same crashes.

libbson/mongoc are compiled with GCC, v6.3 at first, now v7.1 .

Since MongoDB does not run on AIX, I'm using a remote mongodb server on a Linux/x86_64 machine (4.13.11-100.fc25.x86_64).
MongoDB version : mongodb-server-3.2.12-1.fc25.x86_64

It seems to me that the crashes deal with how libbson manages memory:
bson_mem_restore_vtable
bson_malloc0
_bson_iter_next_internal
bson_string_new

I know nearly nothing about mongoc. I need help for figuring out how to debug/fix this issue.

About mongoc, I have:
{{libmongoc 1.9.4 was configured with the following options:

Build configuration:
Enable debugging (slow) : yes
Compile with debug symbols (slow) : full
Enable GCC build optimization : no
Enable automatic init and cleanup : no
Enable mongodb+srv URIs : auto
Enable maintainer flags : no
Code coverage support : no
Cross Compiling : no
Fast counters : no
Shared memory performance counters : yes
SASL : no
SSL : openssl
Snappy Compression : system
Zlib Compression : system
Libbson : system

Documentation:
man : no
HTML : no}}

1. gdb ./test-libmongoc
   (gdb) run (no --no-fork option !)
   { "status": "FAIL", "test_file": "/BulkOperation/upsert_unordered_oversized", "seed": "10627911", "start": 10987519.621764589, "end": 10987521.316436900, "elapsed": 1.694672311 }

   ,
   

   { "status": "FAIL", "test_file": "/BulkOperation/upsert_huge", "seed": "3030471911", "start": 10987522.620592515, "end": 10987523.967977921, "elapsed": 1.347385406 }

   ,
   

   { "status": "FAIL", "test_file": "/BulkOperation/large_inserts_ordered", "seed": "3138342737", "start": 10987531.721175652, "end": 10987533.140875839, "elapsed": 1.419700187 }

   ,
   

   { "status": "FAIL", "test_file": "/BulkOperation/large_inserts_unordered", "seed": "3327859616", "start": 10987533.141157775, "end": 10987534.537897308, "elapsed": 1.396739533 }

   ,
   

   { "status": "FAIL", "test_file": "/Collection/update/oversize", "seed": "3143947750", "start": 10987579.365100689, "end": 10987581.035526324, "elapsed": 1.670425635 }

   ,
   

   { "status": "FAIL", "test_file": "/TOPOLOGY/scanner_connection_error", "seed": "1693182082", "start": 10987742.630362888, "end": 10987742.752703433, "elapsed": 0.122340545 }

   ,

(gdb) run --no-fork
...

{ "status": "PASS", "test_file": "/BulkOperation/upsert_ordered", "seed": "2340171206", "start": 10987861.810715472, "end": 10987861.863608857, "elapsed": 0.052893385 }

,

{ "status": "PASS", "test_file": "/BulkOperation/upsert_unordered", "seed": "4266335484", "start": 10987861.863814916, "end": 10987861.915511878, "elapsed": 0.051696962 }

,

0x09000000004dce94 in pthread_kill () from /usr/lib/libpthreads.a(shr_xpg5_64.o)
(gdb) where
#0 0x09000000004dce94 in pthread_kill () from /usr/lib/libpthreads.a(shr_xpg5_64.o)
#1 0x09000000004dc6cc in _p_raise () from /usr/lib/libpthreads.a(shr_xpg5_64.o)
#2 0x090000000002c550 in raise () from /usr/lib/libc.a(shr_64.o)
#3 0x0900000000082fe8 in abort () from /usr/lib/libc.a(shr_64.o)
#4 0x0900000001ab18d4 in bson_mem_restore_vtable () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#5 0x0900000001ab1944 in memset () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#6 0x0900000001aa7424 in _bson_data () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#7 0x0900000001aa74f4 in _bson_encode_length () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#8 0x0900000001aa772c in _bson_append () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#9 0x0900000001aa79d4 in _bson_append_bson_begin () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#10 0x0900000001aaad04 in bson_append_timestamp () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#11 0x0900000001ac6148 in jsonsl_enable_all_callbacks () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#12 0x0900000001aca8c8 in _bson_json_read_append_dbpointer () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#13 0x0900000001acd59c in bson_json_reader_new_from_fd () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#14 0x0900000001acadb0 in _bad_extended_json () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#15 0x0900000001acb580 in _bson_json_read_end_map () from /opt/freeware/lib/libbson-1.0.a(libbson-1.0.so.0)
#16 0x0000000100080f64 in tmp_bson (json=0xffffffffffff080 "") at tests/test-conveniences.c:94
#17 0x00000001000bae70 in test_upsert_unordered_oversized (ctx=0x8) at tests/test-mongoc-bulk.c:585
#18 0x00000001000855a0 in TestSuite_RunTest (suite=<incomplete type>, test=0x11007ed10, count=0xffffffffffff54c) at tests/TestSuite.c:686
#19 0x0000000100085f1c in TestSuite_RunSerial (suite=<incomplete type>) at tests/TestSuite.c:951
#20 0x0000000100086420 in TestSuite_Run (suite=<incomplete type>) at tests/TestSuite.c:1046
#21 0x000000010000562c in main (argc=2, argv=0xffffffffffff740) at tests/test-libmongoc.c:2179

libbson bundled within mongoc :

1. gmake check ---->> ./test-libbson --threads --no-fork
   ...
   { "status": "PASS", "test_file": "/version", "seed": "254312888", "start": 10984479.058313609, "end": 10984479.058315300, "elapsed": 0.000001691 }

   ,
   

   { "status": "PASS", "test_file": "/bson/writer/custom_realloc", "seed": "2005447092", "start": 10984479.058322513, "end": 10984479.058329431, "elapsed": 0.000006918 }

   ,
   /bin/sh[2]: 24248364 Memory fault(coredump)

1. cd ./src/libbson
2. gdb ./.libs/lt-test-libbson core
   Core was generated by `lt-test-libbson'.
   Program terminated with signal SIGSEGV, Segmentation fault.
   #0 0x090000000001057c in calloc_common () from /usr/lib/libc.a(shr_64.o)
   (gdb) where
   #0 0x090000000001057c in calloc_common () from /usr/lib/libc.a(shr_64.o)
   #1 0x09000000019a5bac in bson_string_new () from /opt/freeware/src/packages/BUILD/mongo-c-driver-1.9.4/64bit/src/libbson/.libs/libbson-1.0.a(libbson-1.0.so.0)
   #2 0x09000000019a7958 in bson_utf8_escape_for_json () from /opt/freeware/src/packages/BUILD/mongo-c-driver-1.9.4/64bit/src/libbson/.libs/libbson-1.0.a(libbson-1.0.so.0)
   #3 0x090000000199cc4c in _bson_as_json_visit_before () from /opt/freeware/src/packages/BUILD/mongo-c-driver-1.9.4/64bit/src/libbson/.libs/libbson-1.0.a(libbson-1.0.so.0)
   #4 0x09000000019a3f4c in bson_iter_visit_all () from /opt/freeware/src/packages/BUILD/mongo-c-driver-1.9.4/64bit/src/libbson/.libs/libbson-1.0.a(libbson-1.0.so.0)
   #5 0x090000000199d290 in _bson_as_json_visit_document () from /opt/freeware/src/packages/BUILD/mongo-c-driver-1.9.4/64bit/src/libbson/.libs/libbson-1.0.a(libbson-1.0.so.0)
   ...
   #404 0x09000000019a4220 in bson_iter_visit_all () from /opt/freeware/src/packages/BUILD/mongo-c-driver-1.9.4/64bit/src/libbson/.libs/libbson-1.0.a(libbson-1.0.so.0)
   #405 0x090000000199d680 in _bson_as_json_visit_all () from /opt/freeware/src/packages/BUILD/mongo-c-driver-1.9.4/64bit/src/libbson/.libs/libbson-1.0.a(libbson-1.0.so.0)
   #406 0x090000000199d818 in bson_as_json () from /opt/freeware/src/packages/BUILD/mongo-c-driver-1.9.4/64bit/src/libbson/.libs/libbson-1.0.a(libbson-1.0.so.0)
   #407 0x000000010002dfa8 in test_bson_as_json_stack_overflow () at tests/test-json.c:671
   #408 0x00000001000010cc in TestSuite_AddHelper (cb_=0x110001f20 <ccl3836H.rw+4528>) at tests/TestSuite.c:304
   #409 0x00000001000017d0 in TestSuite_RunTest (suite=0xfffffffffffeeb8, test=0x110038770, mutex=0xfffffffffffed38, count=0xfffffffffffed78) at tests/TestSuite.c:481
   #410 0x0000000100001df4 in TestSuite_ParallelWorker (data=0x110057d10) at tests/TestSuite.c:675
   #411 0x09000000004c4d34 in _pthread_body () from /usr/lib/libpthread.a(shr_xpg5_64.o)
   #412 0x0000000000000000 in ?? ()
   (gdb)