Add stacktrace on SIGSEGV

[jmjatlanta]

This will enable a stacktrace dump when the SIGSEGV signal is raised.

The stacktrace will be written to the log if Boost is version 1.65 or greater, and the OS is Linux or Windows. Nothing will be written to the log if the Boost version is below 1.65.

To make the output human-legible, compile with at least some debug information (i.e. RelWithDebInfo or Debug)

[pmconrad]

Also in cli_wallet?

[jmjatlanta]

Also in cli_wallet?

Good question. I hesitated, as I assumed a crash there is a bit easier to figure out, and I didn't want the real problem scrolling off the screen. It is a one-liner to add it. If you think it should be there, I'll be happy to include it. Just say the word.

[pmconrad]

Hm. Please?

I think the real cause of a SIGSEGV will rarely show itself. Stacktrace will usually be more helpful than whatever scrolls off-screen.

[pmconrad]

Looks good. Provoked a null-pointer dereference in account_history plugin, with this result:

1188407ms th_a       application.cpp:392           operator()           ] Initializing database...
1195260ms th_a       db_management.cpp:65          reindex              ] reindexing blockchain
1195260ms th_a       db_management.cpp:70          reindex              ] Replaying blocks, starting at 1...
1195392ms th_a       stacktrace.cpp:24             segfault_signal_hand ]  0# 0x00000000015470DC in graphene/programs/witness_node/witness_node
 1# 0x00007FE4707FF1E0 in /lib64/libc.so.6
 2# 0x0000000001134837 in graphene/programs/witness_node/witness_node
 3# graphene::account_history::detail::account_history_plugin_impl::update_account_histories(graphene::protocol::signed_block const&) in graphene/programs/witness_node/witness_node
 4# boost::signals2::detail::signal_impl<void (graphene::protocol::signed_block const&), boost::signals2::optional_last_value<void>, int, std::less<int>, boost::function<void (graphene::protocol::signed_block const&)>, boost::function<void (boost::signals2::connection const&, graphene::protocol::signed_block const&)>, boost::signals2::mutex>::operator()(graphene::protocol::signed_block const&) in graphene/programs/witness_node/witness_node
 5# graphene::chain::database::notify_applied_block(graphene::protocol::signed_block const&) in graphene/programs/witness_node/witness_node
 6# graphene::chain::database::_apply_block(graphene::protocol::signed_block const&) in graphene/programs/witness_node/witness_node
 7# graphene::chain::database::apply_block(graphene::protocol::signed_block const&, unsigned int) in graphene/programs/witness_node/witness_node
 8# graphene::chain::database::reindex(fc::path) in graphene/programs/witness_node/witness_node
 9# graphene::chain::database::open(fc::path const&, std::function<graphene::chain::genesis_state_type ()>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) in graphene/programs/witness_node/witness_node
10# graphene::app::detail::application_impl::startup() in graphene/programs/witness_node/witness_node
11# graphene::app::application::startup() in graphene/programs/witness_node/witness_node
12# main in graphene/programs/witness_node/witness_node
13# __libc_start_main in /lib64/libc.so.6
14# _start in graphene/programs/witness_node/witness_node

(This was a RelWithDebInfo build. Interestingly the output looks the same even after stripping the executable.)

[abitmore]

What will the output look like if compiled with Release?

[jmjatlanta]

I am surprised to see that @pmconrad is correct. I compiled in Release, and received the following by raising SIGSEGV in node.cpp:

3025918ms p2p        stacktrace.cpp:24             segfault_signal_hand ]  0# 0x0000563B1B7ABB9C in ./programs/witness_node/witness_node
 1# 0x00007FC85C1A9F20 in /lib/x86_64-linux-gnu/libc.so.6
 2# raise in /lib/x86_64-linux-gnu/libpthread.so.0
 3# graphene::net::detail::node_impl::p2p_network_connect_loop() in ./programs/witness_node/witness_node
 4# 0x0000563B1B8FA40C in ./programs/witness_node/witness_node
 5# fc::task_base::run_impl() in ./programs/witness_node/witness_node
 6# fc::thread_d::process_tasks() in ./programs/witness_node/witness_node
 7# fc::thread_d::start_process_tasks(boost::context::detail::transfer_t) in ./programs/witness_node/witness_node
 8# make_fcontext in ./programs/witness_node/witness_node

[abitmore]

What's the conclusion?

[pmconrad]

I think this works better than expected.

[abitmore]

There is a typo in commit history (SIGSEV->SIGSEGV), @jmjatlanta I guess it's easy to fix?

[abitmore]

Please fix typo in commit history.

[pmconrad]

@abitmore please re-review.