Details
-
Task
-
Resolution: Fixed
-
Major
-
4.5.0
-
None
Description
During analysis of MB-19557, the Breakpad-created minidump had a strange backtrace (see below). It has a large number of "???" frames in the middle, although the outermost & innermost appear to have the correct IPs. Unfortunately, the local variable information is of limited value.
This is problematic as breakpad minidumps are a critical part of our initial data capture. We need to understand why this backtrace is broken - perhaps once we know the cause of MB-19557 and we can reproduce at-will.
Possible suspects are (for my reference):
- Mismatch between library versions at time of crash / analysis environment
- Bug in breakpad crash-time library (I scanned the recent history but nothing obvious jumped out)
- Bug in breakpad post-processing (minidump-2-core)
- Actually corrupt stack (although the crash looks like a pretty straightforward uncaught exception).
(gdb) bt
|
#0 0x00007f92ba377cc9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
|
#1 0x00007f92ba37b0d8 in __GI_abort () at abort.c:89
|
#2 0x00007f92ba97c535 in __gnu_cxx::__verbose_terminate_handler () at ../../../../src/libstdc++-v3/libsupc++/vterminate.cc:95
|
#3 0x0000000000427f4f in backtrace_terminate_handler () at /home/couchbase/jenkins/workspace/watson-unix/memcached/utilities/terminate_handler.cc:63
|
#4 0x74706f2f20202020 in ?? ()
|
#5 0x61626863756f632f in ?? ()
|
... 45 ?? frames removed ...
|
#50 0x6233346162323966 in ?? ()
|
#51 0x0000000a5d643734 in ?? ()
|
#52 0x00007f92bbd031db in cb_rw_reader_enter (rw=<optimized out>) at /home/couchbase/jenkins/workspace/watson-unix/platform/src/cb_pthreads.cc:391
|
#53 0x00007f92b03fa870 in ?? ()
|
#54 0x0000000000000004 in ?? ()
|
#55 0x00007f92b6dac1a0 in StoredValue::state_temp_init () from /opt/couchbase/lib/ep.so
|
#56 0x00007f919fc57ee0 in ?? ()
|
#57 0x00007f92b6cf48fd in HashTable::unlocked_set (this=0x7f92b6da063f, v=@0x100000000: <error reading variable>, val=..., cas=<optimized out>, allowExisting=<optimized out>,
|
hasMetaData=<optimized out>, policy=FULL_EVICTION, nru=0 '\000', maybeKeyExists=false, isReplication=true) at /home/couchbase/jenkins/workspace/watson-unix/ep-engine/src/stored-value.h:1109
|
... outermost stack frames (appear valid) removed for brevity ...
|
