vfork()问题

[qq_28839381]

#include "stdio.h"
#include <unistd.h>

int main(int argc, char const *argv[])
{
	pid_t result = vfork();

	if(result == 0)
	{

	}
	else if(result > 0)
	{
		printf("123\n");
	}
	else printf("vfork failed\n");

	return 0;
}

运行结果

请问结果为什么会这样？

[nswcfd]

不知道怎么去解释，vfork期待着子进程立刻调用exec的。

[nswcfd]

vfork() differs from fork(2) in that the parent is suspended until the child terminates (either normally, by call- ing _exit(2), or abnormally, after delivery of a fatal signal), or it makes a call to execve(2). Until that point, the child shares all memory with its parent, including the stack. The child must not return from the current func- tion or call exit(3), but may call _exit(2). 由于子进程没有调用execve或者_exit，最终会进入return，这跟最后一句child不能return相违背（因为fork下父子共享stack），其结果是破坏了parent的stack（？有待确认？），导致parent的行为异常。