Subversion Repositories c0or1k

/*

 * l4/posix glue for fork()

 *

 * Copyright (C) 2008 Bahadir Balban

 */

#include <errno.h>

#include <stdio.h>

#include <sys/types.h>

#include <l4lib/ipcdefs.h>

#include <l4lib/utcb.h>

#include <l4/macros.h>

#include INC_GLUE(memory.h)

#include <shpage.h>

#include <libposix.h>

static inline int l4_fork(void)

{

        int err;

        /* Call pager with open() request. Check ipc error. */

        if ((err = l4_sendrecv(pagerid, pagerid, L4_IPC_TAG_FORK)) < 0) {

                print_err("%s: L4 IPC Error: %d.\n", __FUNCTION__, err);

                return err;

        }

        /* Check if syscall itself was successful */

        if ((err = l4_get_retval()) < 0) {

                print_err("%s: OPEN Error: %d.\n", __FUNCTION__, err);

                return err;

        }

        return err;

}

int fork(void)

{

        int ret = l4_fork();

        /* If error, return positive error code */

        if (ret < 0) {

                errno = -ret;

                return -1;

        }

        return ret;

}

extern int arch_clone(l4id_t to, l4id_t from, unsigned int flags);

int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...)

{

        /* Set up the child stack */

        unsigned int *stack = child_stack;

        int ret;

        /* First word of new stack is arg */

        stack[-1] = (unsigned long)arg;

        /* Second word of new stack is function address */

        stack[-2] = (unsigned long)fn;

        /* Write the tag */

        l4_set_tag(L4_IPC_TAG_CLONE);

        /* Write the args as in usual ipc */

        write_mr(L4SYS_ARG0, (unsigned long)child_stack);

        write_mr(L4SYS_ARG1, flags);

        /* Perform an ipc but with different return logic. See implementation. */

        if ((ret = arch_clone(pagerid, pagerid, 0)) < 0) {

                print_err("%s: L4 IPC Error: %d.\n", __FUNCTION__, ret);

                return ret;

        }

        if ((ret = l4_get_retval()) < 0) {

                print_err("%s: CLONE Error: %d.\n", __FUNCTION__, ret);

                return ret;

        }

        return ret;

}