+ register struct proc * newproc;
+ register uid_t uid;
+ thread_act_t cur_act = (thread_act_t)current_act();
+ int count;
+ task_t t;
+ uthread_t ut;
+
+ /*
+ * Although process entries are dynamically created, we still keep
+ * a global limit on the maximum number we will create. Don't allow
+ * a nonprivileged user to use the last process; don't let root
+ * exceed the limit. The variable nprocs is the current number of
+ * processes, maxproc is the limit.
+ */
+ uid = p->p_cred->p_ruid;
+ if ((nprocs >= maxproc - 1 && uid != 0) || nprocs >= maxproc) {
+ tablefull("proc");
+ retval[1] = 0;
+ return (EAGAIN);
+ }
+
+ /*
+ * Increment the count of procs running with this uid. Don't allow
+ * a nonprivileged user to exceed their current limit.
+ */
+ count = chgproccnt(uid, 1);
+ if (uid != 0 && count > p->p_rlimit[RLIMIT_NPROC].rlim_cur) {
+ (void)chgproccnt(uid, -1);
+ return (EAGAIN);
+ }
+
+ ut = (struct uthread *)get_bsdthread_info(cur_act);
+ if (ut->uu_flag & P_VFORK) {
+ printf("vfork called recursively by %s\n", p->p_comm);
+ return (EINVAL);
+ }
+ p->p_flag |= P_VFORK;
+ p->p_vforkcnt++;
+
+ /* The newly created process comes with signal lock held */
+ newproc = (struct proc *)forkproc(p,1);
+
+ LIST_INSERT_AFTER(p, newproc, p_pglist);
+ newproc->p_pptr = p;
+ newproc->task = p->task;
+ LIST_INSERT_HEAD(&p->p_children, newproc, p_sibling);
+ LIST_INIT(&newproc->p_children);
+ LIST_INSERT_HEAD(&allproc, newproc, p_list);
+ LIST_INSERT_HEAD(PIDHASH(newproc->p_pid), newproc, p_hash);
+ TAILQ_INIT(& newproc->p_evlist);
+ newproc->p_stat = SRUN;
+ newproc->p_flag |= P_INVFORK;
+ newproc->p_vforkact = cur_act;
+
+ ut->uu_flag |= P_VFORK;
+ ut->uu_proc = newproc;
+ ut->uu_userstate = (void *)act_thread_csave();
+ ut->uu_vforkmask = ut->uu_sigmask;
+
+ thread_set_child(cur_act, newproc->p_pid);
+
+ newproc->p_stats->p_start = time;
+ newproc->p_acflag = AFORK;
+
+ /*
+ * Preserve synchronization semantics of vfork. If waiting for
+ * child to exec or exit, set P_PPWAIT on child, and sleep on our
+ * proc (in case of exit).
+ */
+ newproc->p_flag |= P_PPWAIT;
+
+ /* drop the signal lock on the child */
+ signal_unlock(newproc);
+
+ retval[0] = newproc->p_pid;
+ retval[1] = 1; /* mark child */
+
+ return (0);
+}
+
+/*
+ * Return to parent vfork ehread()
+ */
+void
+vfork_return(th_act, p, p2, retval)
+ thread_act_t th_act;
+ struct proc * p;
+ struct proc *p2;
+ register_t *retval;
+{
+ long flags;
+ register uid_t uid;
+ thread_t newth, self = current_thread();
+ thread_act_t cur_act = (thread_act_t)current_act();
+ int s, count;
+ task_t t;
+ uthread_t ut;
+
+ ut = (struct uthread *)get_bsdthread_info(cur_act);
+
+ act_thread_catt(ut->uu_userstate);
+
+ /* Make sure only one at this time */
+ p->p_vforkcnt--;
+ if (p->p_vforkcnt <0)
+ panic("vfork cnt is -ve");
+ if (p->p_vforkcnt <=0)
+ p->p_flag &= ~P_VFORK;
+ ut->uu_userstate = 0;
+ ut->uu_flag &= ~P_VFORK;
+ ut->uu_proc = 0;
+ ut->uu_sigmask = ut->uu_vforkmask;
+ p2->p_flag &= ~P_INVFORK;
+ p2->p_vforkact = (void *)0;
+
+ thread_set_parent(cur_act, p2->p_pid);
+
+ if (retval) {
+ retval[0] = p2->p_pid;
+ retval[1] = 0; /* mark parent */
+ }
+
+ return;
+}
+
+thread_act_t
+procdup(
+ struct proc *child,
+ struct proc *parent)
+{
+ thread_act_t thread;
+ task_t task;
+ kern_return_t result;
+ pmap_t pmap;
+ extern task_t kernel_task;
+
+ if (parent->task == kernel_task)
+ result = task_create_local(TASK_NULL, FALSE, FALSE, &task);
+ else
+ result = task_create_local(parent->task, TRUE, FALSE, &task);
+ if (result != KERN_SUCCESS)
+ printf("fork/procdup: task_create failed. Code: 0x%x\n", result);
+ child->task = task;
+ /* task->proc = child; */
+ set_bsdtask_info(task, child);
+ if (child->p_nice != 0)
+ resetpriority(child);
+
+ result = thread_create(task, &thread);
+ if (result != KERN_SUCCESS)
+ printf("fork/procdup: thread_create failed. Code: 0x%x\n", result);
+
+ return(thread);
projects / apple / xnu.git / blobdiff