/*
* fork_create_child
*
* Description: Common operations associated with the creation of a child
* process
*
* Parameters: parent_task parent task
* child_proc child process
* inherit_memory TRUE, if the parents address space is
* to be inherited by the child
* is64bit TRUE, if the child being created will
* be associated with a 64 bit process
* rather than a 32 bit process
*
* Note: This code is called in the fork() case, from the execve() call
* graph, if implementing an execve() following a vfork(), from
* the posix_spawn() call graph (which implicitly includes a
* vfork() equivalent call, and in the system bootstrap case.
*
* It creates a new task and thread (and as a side effect of the
* thread creation, a uthread), which is then associated with the
* process 'child'. If the parent process address space is to
* be inherited, then a flag indicates that the newly created
* task should inherit this from the child task.
*
* As a special concession to bootstrapping the initial process
* in the system, it's possible for 'parent_task' to be TASK_NULL;
* in this case, 'inherit_memory' MUST be FALSE.
*/
thread_t
fork_create_child(task_t parent_task, proc_t child_proc, int inherit_memory, int is64bit)
{
thread_t child_thread = NULL;
task_t child_task;
kern_return_t result;
/* Create a new task for the child process */
result = task_create_internal(parent_task,
inherit_memory,
is64bit,
&child_task);
if (result != KERN_SUCCESS) {
printf("execve: task_create_internal failed. Code: %d\n", result);
goto bad;
}
/* Set the child process task to the new task */
child_proc->task = child_task;
/* Set child task process to child proc */
set_bsdtask_info(child_task, child_proc);
/* Propagate CPU limit timer from parent */
if (timerisset(&child_proc->p_rlim_cpu))
task_vtimer_set(child_task, TASK_VTIMER_RLIM);
/* Set/clear 64 bit vm_map flag */
if (is64bit)
vm_map_set_64bit(get_task_map(child_task));
else
vm_map_set_32bit(get_task_map(child_task));
#if CONFIG_MACF
/* Update task for MAC framework */
/* valid to use p_ucred as child is still not running ... */
mac_task_label_update_cred(child_proc->p_ucred, child_task);
#endif
/*
* Set child process BSD visible scheduler priority if nice value
* inherited from parent
*/
if (child_proc->p_nice != 0)
resetpriority(child_proc);
/* Create a new thread for the child process */
result = thread_create(child_task, &child_thread);
if (result != KERN_SUCCESS) {
printf("execve: thread_create failed. Code: %d\n", result);
task_deallocate(child_task);
child_task = NULL;
}
bad:
thread_yield_internal(1);
return(child_thread);
}
/*
* fork_create_child
*
* Description: Common operations associated with the creation of a child
* process
*
* Parameters: parent_task parent task
* parent_coalitions parent's set of coalitions
* child_proc child process
* inherit_memory TRUE, if the parents address space is
* to be inherited by the child
* is64bit TRUE, if the child being created will
* be associated with a 64 bit process
* rather than a 32 bit process
*
* Note: This code is called in the fork() case, from the execve() call
* graph, if implementing an execve() following a vfork(), from
* the posix_spawn() call graph (which implicitly includes a
* vfork() equivalent call, and in the system bootstrap case.
*
* It creates a new task and thread (and as a side effect of the
* thread creation, a uthread) in the parent coalition set, which is
* then associated with the process 'child'. If the parent
* process address space is to be inherited, then a flag
* indicates that the newly created task should inherit this from
* the child task.
*
* As a special concession to bootstrapping the initial process
* in the system, it's possible for 'parent_task' to be TASK_NULL;
* in this case, 'inherit_memory' MUST be FALSE.
*/
thread_t
fork_create_child(task_t parent_task, coalition_t *parent_coalitions, proc_t child_proc, int inherit_memory, int is64bit)
{
thread_t child_thread = NULL;
task_t child_task;
kern_return_t result;
/* Create a new task for the child process */
result = task_create_internal(parent_task,
parent_coalitions,
inherit_memory,
is64bit,
&child_task);
if (result != KERN_SUCCESS) {
printf("%s: task_create_internal failed. Code: %d\n",
__func__, result);
goto bad;
}
/* Set the child process task to the new task */
child_proc->task = child_task;
/* Set child task process to child proc */
set_bsdtask_info(child_task, child_proc);
/* Propagate CPU limit timer from parent */
if (timerisset(&child_proc->p_rlim_cpu))
task_vtimer_set(child_task, TASK_VTIMER_RLIM);
/* Set/clear 64 bit vm_map flag */
if (is64bit)
vm_map_set_64bit(get_task_map(child_task));
else
vm_map_set_32bit(get_task_map(child_task));
/*
* Set child process BSD visible scheduler priority if nice value
* inherited from parent
*/
if (child_proc->p_nice != 0)
resetpriority(child_proc);
/* Create a new thread for the child process */
result = thread_create_with_continuation(child_task, &child_thread, (thread_continue_t)proc_wait_to_return);
if (result != KERN_SUCCESS) {
printf("%s: thread_create failed. Code: %d\n",
__func__, result);
task_deallocate(child_task);
child_task = NULL;
}
/*
* Tag thread as being the first thread in its task.
*/
thread_set_tag(child_thread, THREAD_TAG_MAINTHREAD);
bad:
thread_yield_internal(1);
return(child_thread);
}
