Linux 平台一种进程代码注入方法

/* fakemain.c
 * Heiher <admin@heiher.info>
 */
 
#include <stdio.h>
 
#define __USE_GNU
#include <dlfcn.h>
 
static void do_something(void)
{
	printf("Hello!\n");
}
 
int __libc_start_main(int (*main)(int, char **, char **),
			int argc, char **ubp_av, void (*init)(void),
			void (*fini)(void), void (*rtld_fini)(void),
			void (*stack_end))
{
	int (*__libc_start_main_real)(int (*main) (int, char **, char **),
				int argc, char **ubp_av, void (*init)(void),
				void (*fini)(void), void (*rtld_fini)(void),
				void (*stack_end));
 
	do_something();
 
	__libc_start_main_real = dlsym(RTLD_NEXT, "__libc_start_main");
 
	return __libc_start_main_real(main, argc, ubp_av, init, fini,
				rtld_fini, stack_end);
}

gcc -o libfakemain.so -fPIC -shared fakemain.c -ldl

LD_PRELOAD=./libfakemain.so ls

Hello!
fakemain.c  hotkey  hotkey.vala  libfakemain.so