linux - Linux ELF 上的 BIND_NOW 是什么？

Question

在解析从共享库派生的函数时，我遇到了一个问题，我意识到这个问题与 BIND_NOW 有关，它是 ELF 的安全功能之一。

由于网上没有足够的信息，我暂时不能更进一步。什么是 BIND_NOW？

Answer 1

意思是在加载对象的时候就解析符号(而不是在使用的时候解析，这叫惰性绑定(bind))

引自man 3 dlopen:

One of the following two values must be included in flag:

   RTLD_LAZY
          Perform lazy binding.  Only resolve symbols as the code that
          references them is executed.  If the symbol is never
          referenced, then it is never resolved.  (Lazy binding is
          performed only for function references; references to
          variables are always immediately bound when the library is
          loaded.)

   RTLD_NOW
          If this value is specified, or the environment variable
          LD_BIND_NOW is set to a nonempty string, all undefined symbols
          in the library are resolved before dlopen() returns.  If this
          cannot be done, an error is returned.

已编辑:另见 this link ，这是我在谷歌搜索时发现的。