linux - dlopen/dlclose 与几个 so，在 dlopen 上被阻止

Question

两次不同的 dlopen 和 dlclose 几次，在 dlopen 上被阻止。

卡在dlopen上，它不输出任何内容，cpuidle降至0%，并且无法通过ctrl+c退出。

LOG_TRACE("attaching...");
handle = dlopen(plugin_path.c_str(), RTLD_LAZY);
LOG_DEBUG("dlopen called");     // this line did not output, after success couple of times;

然后我使用gdb附加到程序:

(gdb) bt
#0  0x0000002a960dbe60 in tcmalloc::ThreadCache::InitTSD () at src/thread_cache.cc:321
#1  0x0000002a960d51bf in TCMallocGuard (this=Variable "this" is not available.) at src/tcmalloc.cc:908
#2  0x0000002a960d5e00 in global constructors keyed to _ZN61FLAG__namespace_do_not_use_directly_use_DECLARE_int64_instead43FLAGS_tcmalloc_large_alloc_report_thresholdE () at src/tcmalloc.cc:935
#3  0x0000002a960fafc6 in __do_global_ctors_aux () at ./src/base/spinlock.h:54
#4  0x0000002a96010f13 in _init () from ../plugins/libmonitor.so
#5  0x0000002a00000000 in ?? ()
#6  0x000000302ad0acaf in _dl_init_internal () from /lib64/ld-linux-x86-64.so.2
#7  0x000000302aff725c in dl_open_worker () from /lib64/tls/libc.so.6
#8  0x000000302ad0aa60 in _dl_catch_error () from /lib64/ld-linux-x86-64.so.2
#9  0x000000302aff79fa in _dl_open () from /lib64/tls/libc.so.6
#10 0x000000302b201054 in dlopen_doit () from /lib64/libdl.so.2
#11 0x000000302ad0aa60 in _dl_catch_error () from /lib64/ld-linux-x86-64.so.2
#12 0x000000302b201552 in _dlerror_run () from /lib64/libdl.so.2
#13 0x000000302b201092 in dlopen@@GLIBC_2.2.5 () from /lib64/libdl.so.2
#14 0x000000000041b559 in uap::meta::MetaManageServiceHandler::plugin_action this=0xb26000, _return=@0x7fbffff500, plugin_name=@0x7fbffff4e0, plugin_path=@0x7fbffff570, t=Variable "t" is not available.)
at /usr/lib/gcc/x86_64-redhat-linux/3.4.5/../../../../include/c++/3.4.5/bits/basic_string.h:1456
#15 0x000000000041b0bc in uap::meta::MetaManageServiceHandler::plugin_action (this=0xb26000, _return=@0x7fbffff500, plugin_name=@0x7fbffff4e0, plugin_path=@0x7fbffff570, t=uap::meta::PluginActionType::RELOAD)
at server/service_handler.cpp:173
#16 0x0000000000417641 in uap::meta::test_Service_Handler_suite_test_case_manage_service_plugin_action_Test::TestBody (this=0xb16080) at test_load.cpp:73
#17 0x00000000004446c6 in testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void> (object=0xb16080, method={__pfn = 0x21, __delta = 0}, location=0x537f30 "the test body")
at ../../../../com/btest/gtest/src/gtest.cc:2744
#18 0x000000000042dd1c in testing::Test::Run (this=0xb16080) at ../../../../com/btest/gtest/src/gtest.cc:2766
#19 0x000000000042e8b4 in testing::TestInfo::Run (this=0xb17160) at ../../../../com/btest/gtest/src/gtest.cc:2958
#20 0x000000000042f415 in testing::TestCase::Run (this=0xb23000, runtype=0) at ../../../../com/btest/gtest/src/gtest.cc:3160
#21 0x0000000000436352 in testing::internal::UnitTestImpl::RunAllTests (this=0xb22000) at ../../../../com/btest/gtest/src/gtest.cc:5938
#22 0x0000000000434299 in testing::UnitTest::Run (this=0x6f4220, run_type=0) at ../../../../com/btest/gtest/src/gtest.cc:5449
#23 0x0000000000434268 in testing::UnitTest::Run (this=0x6f4220) at ../../../../com/btest/gtest/src/gtest.cc:5387
#24 0x0000000000455404 in main (argc=1, argv=0x7fbffff8c8) at ../../../../com/btest/gtest/src/gtest_main.cc:38

实际上我重新定义了四个函数:

void __attribute__((constructor)) dlinit()                                                                                                                                                                   
{
}

void __attribute__((destructor)) dldeinit()
{
}

void _init()
{
}

void _fini()
{
}

Answer 1

我想我已经找到了根本原因:在gdb信息中，挂起来自tcmalloc，我已经阅读了tcmalloc相关代码和几个锁，然后我在没有tcmalloc的情况下编译并链接so，没有任何反应，这将是与so一起工作时的tcmalloc错误