在共享库中查找已加载共享库的位置? [英] Find location of loaded shared library, from in that shared library?

问题描述

从共享库中的函数中，在运行的进程中(用C编写)，如何发现共享库从何处加载?

From a function in a shared library, inside a running process (written in C), how do I discover where that shared library was loaded from?

我找到的所有答案都涉及在命令行中使用诸如 ldd 之类的东西，或者通过窥视/proc/self/maps .

All of the answers I've found involve using things such as ldd at the command line, or by peeking in /proc/self/maps.

在Win32上，我只使用 GetModuleFileName(GetModuleHandle("foo.dll")，szPath，COUNTOF(szPath)).什么是Linux等效项?

On Win32, I'd just use GetModuleFileName(GetModuleHandle("foo.dll"), szPath, COUNTOF(szPath)). What's the Linux equivalent?

奖金问题:我需要在OS X中使用相同的信息.

推荐答案

实现此目标的一种方法是使用dladdr:

One method to achieve this is to make use of dladdr:

共享对象的代码:

$ cat so.c 
#include <stdio.h>
#include <dlfcn.h>
void test_so_func()
{
 Dl_info info;
 if (dladdr(test_so_func, &info))
 {
    printf("Loaded from path = %s\n", info.dli_fname);
 }
 printf("hello\n");
}

主要执行者的代码:

$ cat test.c
void test_so_func();

int main() {
  test_so_func();
  return 0;
}

Makefile:

$ cat Makefile 
test: test.o libso.so
    gcc test.o -o $@ -Wl,-L.,-lso,-rpath,'$$ORIGIN'

clean:
    -rm -f libso.so test.o test

libso.so: so.c
    gcc -D_GNU_SOURCE=1 -fPIC -shared $< -o $@ -lc -ldl

test.o: test.c
    gcc -fPIC -c $< -o $@

让我们编译吧！

$ make
gcc -fPIC -c test.c -o test.o
gcc -D_GNU_SOURCE=1 -fPIC -shared so.c -o libso.so -lc -ldl
gcc test.o -o test -Wl,-L.,-lso,-rpath,'$ORIGIN'

测试此二进制文件.

$ ./test 
Loaded from path = /spare/scratch/1564054710/libso.so
hello

验证libso.so确实在讲真话.

Verify that libso.so is indeed speaking the truth.

$ ldd ./test
    linux-vdso.so.1 =>  (0x00007ffdf55d5000)
    libso.so => /spare/scratch/1564054710/./libso.so (0x00007fbcc4602000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fbcc4238000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fbcc4034000)
    /lib64/ld-linux-x86-64.so.2 (0x00007fbcc4804000)

此答案的功劳归于 https://github.com/mingwandroid

这篇关于在共享库中查找已加载共享库的位置?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！