How to implement vfork using clone?

archieval · 04-24-2007, 03:02 AM

Hi everyone! I am using a 2.6.10 kernel. In user space, how will I implement the vfork() system call using the clone system call? what should I place in the child stack argument knowing that in vfork, the child execute in the same address space as in the parent?

The definition of clone is:
int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg);

Thanks!

osor · 04-24-2007, 08:00 PM

You might want to look at an open source libc implementation (e.g., glibc, dietlibc, uClibc, etc.).

archieval · 04-24-2007, 08:23 PM

Thanks! But where can I find these libc's? I have tried to use this one:

void *child_stack;
child stack = malloc(10000);

clone(myfunc, child_stack, CLONE_VM|CLONE_VFORK|SIGCHLD, 0);

but it gives me an error like library something not found in "lib.so" something.
However when I tried not to include the CLONE_VM, the task is created but at the end, there is always a segmentation fault message.