Exemple #1
0
/*
 * Finish a fork operation, with process p2 nearly set up.
 * Copy and update the kernel stack and pcb, making the child
 * ready to run, and marking it so that it can return differently
 * than the parent.  Returns 1 in the child process, 0 in the parent.
 */
void
cpu_fork(struct proc *p1, struct proc *p2, void *stack, size_t stacksize,
    void (*func)(void *), void *arg)
{
	struct pcb *pcb = &p2->p_addr->u_pcb;
	struct trapframe *tf;
	struct switchframe *sf;

	/*
	 * If fpuproc != p1, then the fpu h/w state is irrelevant and the
	 * state had better already be in the pcb.  This is true for forks
	 * but not for dumps.
	 *
	 * If fpuproc == p1, then we have to save the fpu h/w state to
	 * p1's pcb so that we can copy it.
	 */
	if (p1->p_addr->u_pcb.pcb_fpcpu != NULL)
		fpusave_proc(p1, 1);

	p2->p_md.md_flags = p1->p_md.md_flags;

#ifdef DIAGNOSTIC
	if (p1 != curproc && p1 != &proc0)
		panic("cpu_fork: curproc");
#endif
	*pcb = p1->p_addr->u_pcb;

	/*
	 * Activate the address space.
	 */
	pmap_activate(p2);

	/* Record where this process's kernel stack is */
	pcb->pcb_kstack = (u_int64_t)p2->p_addr + USPACE - 16;

	/*
	 * Copy the trapframe.
	 */
	p2->p_md.md_regs = tf = (struct trapframe *)pcb->pcb_kstack - 1;
	*tf = *p1->p_md.md_regs;

	setredzone(p2);

	/*
	 * If specified, give the child a different stack.
	 */
	if (stack != NULL)
		tf->tf_rsp = (u_int64_t)stack + stacksize;

	sf = (struct switchframe *)tf - 1;
	sf->sf_r12 = (u_int64_t)func;
	sf->sf_r13 = (u_int64_t)arg;
	sf->sf_rip = (u_int64_t)proc_trampoline;
	pcb->pcb_rsp = (u_int64_t)sf;
	pcb->pcb_rbp = 0;
}
Exemple #2
0
/*
 * Finish a fork operation, with process p2 nearly set up.
 * Copy and update the kernel stack and pcb, making the child
 * ready to run, and marking it so that it can return differently
 * than the parent.  Returns 1 in the child process, 0 in the parent.
 * We currently double-map the user area so that the stack is at the same
 * address in each process; in the future we will probably relocate
 * the frame pointers on the stack after copying.
 */
void
cpu_fork(struct proc *p1, struct proc *p2, void *stack, size_t stacksize,
    void (*func)(void *), void *arg)
{
	struct pcb *pcb = &p2->p_addr->u_pcb;
	struct trapframe *tf;
	struct switchframe *sf;

	/*
	 * If fpuproc != p1, then the fpu h/w state is irrelevant and the
	 * state had better already be in the pcb.  This is true for forks
	 * but not for dumps.
	 *
	 * If fpuproc == p1, then we have to save the fpu h/w state to
	 * p1's pcb so that we can copy it.
	 */
	if (p1->p_addr->u_pcb.pcb_fpcpu != NULL)
		fpusave_proc(p1, 1);

	p2->p_md.md_flags = p1->p_md.md_flags;
	syscall_intern(p2);

	/* Copy pcb from proc p1 to p2. */
	if (p1 == curproc) {
		/* Sync the PCB before we copy it. */
		savectx(curpcb);
	}
#ifdef DIAGNOSTIC
	else if (p1 != &proc0)
		panic("cpu_fork: curproc");
#endif
	*pcb = p1->p_addr->u_pcb;

	/*
	 * Preset these so that gdt_compact() doesn't get confused if called
	 * during the allocations below.
	 *
	 * Note: pcb_ldt_sel is handled in the pmap_activate() call when
	 * we run the new process.
	 */
	p2->p_md.md_tss_sel = GSEL(GNULL_SEL, SEL_KPL);

	/*
	 * Activate the addres space.  Note this will refresh pcb_ldt_sel.
	 */
	pmap_activate(p2);

	/* Fix up the TSS. */
	pcb->pcb_tss.tss_rsp0 = (u_int64_t)p2->p_addr + USPACE - 16;
	pcb->pcb_tss.tss_ist[0] = (u_int64_t)p2->p_addr + PAGE_SIZE - 16;
	p2->p_md.md_tss_sel = tss_alloc(pcb);

	/*
	 * Copy the trapframe.
	 */
	p2->p_md.md_regs = tf = (struct trapframe *)pcb->pcb_tss.tss_rsp0 - 1;
	*tf = *p1->p_md.md_regs;

	setredzone(p2);

	/*
	 * If specified, give the child a different stack.
	 */
	if (stack != NULL)
		tf->tf_rsp = (u_int64_t)stack + stacksize;

	sf = (struct switchframe *)tf - 1;
	sf->sf_ppl = IPL_NONE;
	sf->sf_r12 = (u_int64_t)func;
	sf->sf_r13 = (u_int64_t)arg;
	if (func == child_return)
		sf->sf_rip = (u_int64_t)child_trampoline;
	else
		sf->sf_rip = (u_int64_t)proc_trampoline;
	pcb->pcb_rsp = (u_int64_t)sf;
	pcb->pcb_rbp = 0;
}
Exemple #3
0
void
cpu_swapin(struct proc *p)
{
	setredzone(p);
}