It takes the address of the `main` function of a program, `argc` and `argv`. `init` and `fini` functions are constructor and destructor of the program. The `rtld_fini` is the termination function which will be called after the program will be exited to terminate and free its dynamic section. The last parameter of the `__libc_start_main` is a pointer to the stack of the program. Before we can call the `__libc_start_main` function, all of these parameters must be prepared and passed to it. Let's return to the [sysdeps/x86_64/start.S](https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/x86_64/start.S;h=f1b961f5ba2d6a1ebffee0005f43123c4352fbf4;hb=HEAD) assembly file and continue to see what happens before the `__libc_start_main` function will be called from there.
We can get all the arguments we need for `__libc_start_main` function from the stack. As`_start` is called, our stack looks like:
We can get all the arguments we need for `__libc_start_main` function from the stack. At the very beginning, when`_start` is called, our stack looks like:
```
+-----------------+
| NULL |
+-----------------+
| ... |
| envp |
| ... |
+-----------------+
| NULL |
+------------------
| argv | <-rsp
| ... |
| argv |
| ... |
+------------------
| argc |
| argc |<-rsp
+-----------------+
```
@ -302,11 +306,15 @@ After we cleared `ebp` register and saved the address of the termination functio
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7 years ago
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