seastar segfaults on Ubuntu 15.10

[shivshankardayal]

I built seastar on Ubuntu 15.10 with DPDK. While the httpd works seastar segfaults when run. I tried both the debug and release builds.

[avikivity]

Please post a backtrace here.

[shivshankardayal]

Following is what I get when I use gdb:

(gdb) r
Starting program: /home/shiv/Downloads/seastar/build/debug/apps/seastar/seastar 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffee5ff700 (LWP 21564)]
core/reactor.hh:949:13: runtime error: reference binding to null pointer of type 'struct reactor'

Program received signal SIGSEGV, Segmentation fault.
0x0000000000671a81 in std::_Hashtable<int, std::pair<int const, reactor::signals::signal_handler>, std::allocator<std::pair<int const, reactor::signals::signal_handler> >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_bucket_index (this=0xe80, __k=@0x60400000df18: 10, __c=10)
    at /usr/include/c++/5/bits/hashtable.h:621
621           { return __hash_code_base::_M_bucket_index(__k, __c, _M_bucket_count); }
(gdb) bt
#0  0x0000000000671a81 in std::_Hashtable<int, std::pair<int const, reactor::signals::signal_handler>, std::allocator<std::pair<int const, reactor::signals::signal_handler> >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_bucket_index (this=0xe80, __k=@0x60400000df18: 10, __c=10)
    at /usr/include/c++/5/bits/hashtable.h:621
#1  0x0000000000671767 in std::_Hashtable<int, std::pair<int const, reactor::signals::signal_handler>, std::allocator<std::pair<int const, reactor::signals::signal_handler> >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_emplace<std::piecewise_construct_t const&, std::tuple<int>, std::tuple<int, std::function<void ()> > >(std::integral_constant<bool, true>, std::piecewise_construct_t const&, std::tuple<int>&&, std::tuple<int, std::function<void ()> >&&) (this=0xe80) at /usr/include/c++/5/bits/hashtable.h:1539
#2  0x000000000062e1a3 in std::_Hashtable<int, std::pair<int const, reactor::signals::signal_handler>, std::allocator<std::pair<int const, reactor::signals::signal_handler> >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::emplace<std::piecewise_construct_t const&, std::tuple<int>, std::tuple<int, std::function<void ()> > >(std::piecewise_construct_t const&, std::tuple<int>&&, std::tuple<int, std::function<void ()> >&&) (this=0xe80)
    at /usr/include/c++/5/bits/hashtable.h:726
#3  0x0000000000600c0b in std::unordered_map<int, reactor::signals::signal_handler, std::hash<int>, std::equal_to<int>, std::allocator<std::pair<int const, reactor::signals::signal_handler> > >::emplace<std::piecewise_construct_t const&, std::tuple<int>, std::tuple<int, std::function<void ()> > >(std::piecewise_construct_t const&, std::tuple<int>&&, std::tuple<int, std::function<void ()> >&&) (this=0xe80) at /usr/include/c++/5/bits/unordered_map.h:380
#4  0x00000000004198b6 in reactor::signals::handle_signal(int, std::function<void ()>&&) (this=0xe78, signo=10, 
    handler=<unknown type in /home/shiv/Downloads/seastar/build/debug/apps/seastar/seastar, CU 0x3d692, DIE 0x1839c0>) at core/reactor.cc:168
#5  0x00000000004443f2 in thread_pool::thread_pool (this=0x7fffffffd538) at core/reactor.cc:1673
#6  0x000000000041b034 in reactor::reactor (this=0x7fffffffc680) at core/reactor.cc:218
#7  0x0000000000417b54 in main (ac=1, av=0x7fffffffdf98) at apps/seastar/main.cc:27


And if I run debug build then it gives following output:

shiv@freedom:~/Downloads/seastar/build/debug/apps/seastar$ ./seastar 
core/reactor.hh:949:13: runtime error: reference binding to null pointer of type 'struct reactor'
ASAN:SIGSEGV
=================================================================
==21569==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000e88 (pc 0x000000671a81 bp 0x7ffda1df17b0 sp 0x7ffda1df1780 T0)
    #0 0x671a80 in std::_Hashtable<int, std::pair<int const, reactor::signals::signal_handler>, std::allocator<std::pair<int const, reactor::signals::signal_handler> >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_bucket_index(int const&, unsigned long) const (/home/shiv/Downloads/seastar/build/debug/apps/seastar/seastar+0x671a80)
    #1 0x671766 in std::pair<std::__detail::_Node_iterator<std::pair<int const, reactor::signals::signal_handler>, false, false>, bool> std::_Hashtable<int, std::pair<int const, reactor::signals::signal_handler>, std::allocator<std::pair<int const, reactor::signals::signal_handler> >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_emplace<std::piecewise_construct_t const&, std::tuple<int>, std::tuple<int, std::function<void ()> > >(std::integral_constant<bool, true>, std::piecewise_construct_t const&, std::tuple<int>&&, std::tuple<int, std::function<void ()> >&&) (/home/shiv/Downloads/seastar/build/debug/apps/seastar/seastar+0x671766)
    #2 0x62e1a2 in std::pair<std::__detail::_Node_iterator<std::pair<int const, reactor::signals::signal_handler>, false, false>, bool> std::_Hashtable<int, std::pair<int const, reactor::signals::signal_handler>, std::allocator<std::pair<int const, reactor::signals::signal_handler> >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::emplace<std::piecewise_construct_t const&, std::tuple<int>, std::tuple<int, std::function<void ()> > >(std::piecewise_construct_t const&, std::tuple<int>&&, std::tuple<int, std::function<void ()> >&&) (/home/shiv/Downloads/seastar/build/debug/apps/seastar/seastar+0x62e1a2)
    #3 0x600c0a in std::pair<std::__detail::_Node_iterator<std::pair<int const, reactor::signals::signal_handler>, false, false>, bool> std::unordered_map<int, reactor::signals::signal_handler, std::hash<int>, std::equal_to<int>, std::allocator<std::pair<int const, reactor::signals::signal_handler> > >::emplace<std::piecewise_construct_t const&, std::tuple<int>, std::tuple<int, std::function<void ()> > >(std::piecewise_construct_t const&, std::tuple<int>&&, std::tuple<int, std::function<void ()> >&&) (/home/shiv/Downloads/seastar/build/debug/apps/seastar/seastar+0x600c0a)
    #4 0x4198b5 in reactor::signals::handle_signal(int, std::function<void ()>&&) core/reactor.cc:168
    #5 0x4443f1 in thread_pool::thread_pool() core/reactor.cc:1673
    #6 0x41b033 in reactor::reactor() core/reactor.cc:218
    #7 0x417b53 in main apps/seastar/main.cc:27
    #8 0x7f89d35bfa3f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x20a3f)
    #9 0x4179d8 in _start (/home/shiv/Downloads/seastar/build/debug/apps/seastar/seastar+0x4179d8)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV ??:0 std::_Hashtable<int, std::pair<int const, reactor::signals::signal_handler>, std::allocator<std::pair<int const, reactor::signals::signal_handler> >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_bucket_index(int const&, unsigned long) const
==21569==ABORTING

The binary is build on Ubuntu 15.10 with DPDK. I have used gcc 5.2.1. If you need any other information I will be happy to provide that.

[avikivity]

apps/seastar/main.cc is outdated (and does nothing anyway). Try building build/release/apps/httpd/httpd or another application.

[nyh]

On Mon, Dec 21, 2015 at 3:05 PM, Avi Kivity [email protected]
wrote:

apps/seastar/main.cc is outdated (and does nothing anyway).

So it should be deleted :-)

[shivshankardayal]

Thanks for confirming. httpd is working fine else I would have reported. :)