dlopen malloc僵局

Pau*_*aet 5 c malloc deadlock dlopen

我们有一些经常陷入僵局的单元测试.使用GDB进行更密切的检查显示以下内容:

线程1:

(gdb) bt
#0  0x00110424 in __kernel_vsyscall ()
#1  0x00c681a3 in __lll_lock_wait_private () from /lib/libc.so.6
#2  0x00bf09fb in _L_lock_515 () from /lib/libc.so.6
#3  0x00bf068c in tr_mallochook () from /lib/libc.so.6
#4  0x00bece22 in calloc () from /lib/libc.so.6
#5  0x00b5ed93 in _dl_new_object () from /lib/ld-linux.so.2
#6  0x00b5b287 in _dl_map_object_from_fd () from /lib/ld-linux.so.2
#7  0x00b5c521 in _dl_map_object () from /lib/ld-linux.so.2
#8  0x00b66f43 in dl_open_worker () from /lib/ld-linux.so.2
#9  0x00b629a6 in _dl_catch_error () from /lib/ld-linux.so.2
#10 0x00b66a06 in _dl_open () from /lib/ld-linux.so.2
#11 0x00d38c3b in dlopen_doit () from /lib/libdl.so.2
#12 0x00b629a6 in _dl_catch_error () from /lib/ld-linux.so.2
#13 0x00d3903c in _dlerror_run () from /lib/libdl.so.2
#14 0x00d38b71 in dlopen@@GLIBC_2.1 () from /lib/libdl.so.2
...

线程2:

#0  0x00110424 in __kernel_vsyscall ()
#1  0x00d4c059 in __lll_lock_wait () from /lib/libpthread.so.0
#2  0x00d4740e in _L_lock_752 () from /lib/libpthread.so.0
#3  0x00d4731a in pthread_mutex_lock () from /lib/libpthread.so.0
#4  0x00c95dd2 in _dl_addr () from /lib/libc.so.6
#5  0x00bf0425 in tr_where () from /lib/libc.so.6
#6  0x00bf06bd in tr_mallochook () from /lib/libc.so.6
#7  0x00bed01b in malloc () from /lib/libc.so.6
....

我在互联网上做了很多搜索,但我无法确定我是否做错了什么,或者我是否在库中发现了一个错误.

Max*_*kin 5

glibc的dlopen()代码似乎不是线程安全的.

它看起来像你的代码调用malloc(),并dlopen()从两个线程同时.它看起来像malloc()调用命中一个未解析的动态符号并尝试使用_dl_addr()它来解决它,这意味着您正在执行的二进制文件与延迟绑定(默认ld行为)相关联,这就是运行时链接程序在第一次调用时根据需要解析符号的原因.尝试将其与-Wl,-z,now gcc链接器选项链接,以使运行时链接程序在启动应用程序之前解析所有符号.

这个bug看起来类似于我提交的bug报告.