Using dlopen on libnglib.so crashes in std::map #201
Description
Version v6.2.2404, from openSUSE Tumbleweed.
Here's a weird one.
Using dlopen on libnglib.so will cause a crash during the static initialization of global variable below in rw_medit.cpp:
static RegisterUserFormat reg_medit ("Medit Format", {".mesh"},
ReadMeditFormat,
WriteMeditFormat);
Here's the gdb stack trace:
#0 0x00007fcd066d641e in std::local_Rb_tree_decrement (__x=0x7fcd0610d688 <netgen::UserFormatRegister::format_to_entry_index[abi:cxx11]+8>) at ../../../../../libstdc++-v3/src/c++98/tree.cc:98
#1 std::_Rb_tree_decrement (__x=__x@entry=0x7fcd0610d688 <netgen::UserFormatRegister::format_to_entry_index[abi:cxx11]+8>) at ../../../../../libstdc++-v3/src/c++98/tree.cc:123
#2 0x00007fcd05f87790 in std::_Rb_tree_iterator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> >::operator-- (this=<synthetic pointer>) at /usr/include/c++/14/bits/stl_tree.h:298
#3 std::_Rb_tree<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int>, std::_Select1st<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> > >::_M_get_insert_unique_pos (this=this@entry=0x7fcd0610d680 <netgen::UserFormatRegister::format_to_entry_index[abi:cxx11]>, __k=...) at /usr/include/c++/14/bits/stl_tree.h:2123
#4 0x00007fcd05f884d1 in std::_Rb_tree<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int>, std::_Select1st<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> > >::_M_get_insert_hint_unique_pos(std::_Rb_tree_const_iterator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) [clone .isra.0] (this=this@entry=0x7fcd0610d680 <netgen::UserFormatRegister::format_to_entry_index[abi:cxx11]>, __position=..., __k=...)
at /usr/include/c++/14/bits/stl_tree.h:2220
#5 0x00007fcd05f19787 in std::_Rb_tree<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int>, std::_Select1st<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> > >::_M_emplace_hint_unique<std::piecewise_construct_t const&, std::tuple<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&>, std::tuple<> >(std::_Rb_tree_const_iterator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> >, std::piecewise_construct_t const&, std::tuple<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&>&&, std::tuple<>&&) [clone .constprop.0] [clone .isra.0] (__pos=..., this=<optimized out>) at /usr/include/c++/14/bits/stl_tree.h:2459
#6 0x00007fcd05b6888e in std::map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, int> > >::operator[] (this=<optimized out>, __k="Medit Format") at /usr/include/c++/14/bits/stl_map.h:513
#7 netgen::UserFormatRegister::Register (entry=...) at /usr/src/debug/netgen-6.2.2404/libsrc/interface/writeuser.hpp:35
#8 netgen::RegisterUserFormat::RegisterUserFormat(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, ngcore::Array<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>, std::optional<std::function<void (netgen::Mesh&, std::filesystem::__cxx11::path const&)> >, std::optional<std::function<void (netgen::Mesh const&, std::filesystem::__cxx11::path const&)> >, std::function<bool (std::filesystem::__cxx11::path const&)>) [clone .isra.0] (format=..., extensions=..., read=..., write=..., ftest=..., this=<optimized out>) at /usr/src/debug/netgen-6.2.2404/libsrc/interface/writeuser.hpp:62
#9 0x00007fcd05b6a382 in _sub_I_65535_0.0 () from /usr/lib64/netgen/libnglib.so
#10 0x00007fcd06a4869e in call_init (l=<optimized out>, argc=1, argv=0x7ffe49707378, env=0x7ffe49707388) at dl-init.c:74
#11 call_init (l=<optimized out>, argc=1, argv=0x7ffe49707378, env=0x7ffe49707388) at dl-init.c:26
#12 0x00007fcd06a4879c in _dl_init (main_map=0x1744e2e0, argc=1, argv=0x7ffe49707378, env=0x7ffe49707388) at dl-init.c:121
#13 0x00007fcd06a455fe in __GI__dl_catch_exception (exception=exception@entry=0x0, operate=operate@entry=0x7fcd06a4f73e <call_dl_init>, args=args@entry=0x7ffe49706df0) at dl-catch.c:215
#14 0x00007fcd06a4f6ce in dl_open_worker (a=a@entry=0x7ffe49706f90) at dl-open.c:829
#15 0x00007fcd06a45571 in __GI__dl_catch_exception (exception=exception@entry=0x7ffe49706f70, operate=operate@entry=0x7fcd06a4f63e <dl_open_worker>, args=args@entry=0x7ffe49706f90) at dl-catch.c:241
#16 0x00007fcd06a4fb2c in _dl_open (file=0x402004 "/usr/lib64/netgen/libnglib.so", mode=<optimized out>, caller_dlopen=0x401184 <main+30>, nsid=<optimized out>, argc=1, argv=0x7ffe49707378, env=0x7ffe49707388) at dl-open.c:905
#17 0x00007fcd06293a3c in dlopen_doit (a=a@entry=0x7ffe49707200) at dlopen.c:56
#18 0x00007fcd06a45571 in __GI__dl_catch_exception (exception=exception@entry=0x7ffe49707160, operate=0x7fcd062939de <dlopen_doit>, args=0x7ffe49707200) at dl-catch.c:241
#19 0x00007fcd06a456a3 in _dl_catch_error (objname=0x7ffe497071b8, errstring=0x7ffe497071c0, mallocedp=0x7ffe497071b7, operate=<optimized out>, args=<optimized out>) at dl-catch.c:260
#20 0x00007fcd062934e7 in _dlerror_run (operate=operate@entry=0x7fcd062939de <dlopen_doit>, args=args@entry=0x7ffe49707200) at dlerror.c:138
#21 0x00007fcd06293b01 in dlopen_implementation (file=<optimized out>, mode=<optimized out>, dl_caller=<optimized out>) at dlopen.c:71
#22 ___dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:81
#23 0x0000000000401184 in main ()
It was generated from execution this simple program that is segfaulting in dlopen:
#include <dlfcn.h>
int main(int argc, char **argv) {
dlopen("/usr/lib64/netgen/libnglib.so", RTLD_NOW);
return 0;
}
I tried to understand what could cause it but failed.
I tried a minimal C++ shared lib mimicking what is done in writeuser.hpp/writeuser.cpp but it did not crash.
Quite puzling this one. If that helps, I attached the compilation log of netgen: