/*
* 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;
}
/*
* 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;
}
void
cpu_swapin(struct proc *p)
{
setredzone(p);
}
