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Fix fork() for new task switching model

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This commit is contained in:
Justin C. Miller
2019-04-03 10:08:26 -07:00
parent 8375870af6
commit c605793a9d
13 changed files with 172 additions and 97 deletions
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35
src/kernel/scheduler.cpp
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@@ -26,20 +26,22 @@ extern "C" {
uintptr_t load_process_image(const void *image_start, size_t bytes, process *proc);
};
extern uint64_t idle_stack_end;
scheduler::scheduler(lapic *apic) :
m_apic(apic),
m_next_pid(1)
{
auto *idle = m_process_allocator.pop();
idle->setup_kernel_stack();
uint8_t last_pri = num_priorities - 1;
// The kernel idle task, also the thread we're in now
idle->pid = 0;
idle->ppid = 0;
idle->priority = last_pri;
idle->rsp = 0; // This will get set when we switch away
idle->rsp = 0; // This will get set when we switch away
idle->rsp3 = 0; // Never used for the idle task
idle->rsp0 = reinterpret_cast<uintptr_t>(&idle_stack_end);
idle->pml4 = page_manager::get_pml4();
idle->quanta = process_quanta;
idle->flags =
@@ -124,24 +126,6 @@ scheduler::create_process(pid_t pid)
return proc;
}
static uintptr_t
add_fake_task_return(uintptr_t rsp, uintptr_t rbp, uintptr_t rip)
{
// Initialize a new empty stack with a fake return segment
// for returning out of task_switch
rsp -= sizeof(uintptr_t) * 7;
uintptr_t *stack = reinterpret_cast<uintptr_t*>(rsp);
stack[6] = rip; // return rip
stack[5] = rbp; // rbp
stack[4] = 0xbbbbbbbb; // rbx
stack[3] = 0x12121212; // r12
stack[2] = 0x13131313; // r13
stack[1] = 0x14141414; // r14
stack[0] = 0x15151515; // r15
return rsp;
}
void
scheduler::load_process(const char *name, const void *data, size_t size)
{
@@ -165,9 +149,8 @@ scheduler::load_process(const char *name, const void *data, size_t size)
stack[1] = reinterpret_cast<uintptr_t>(size);
stack[2] = reinterpret_cast<uintptr_t>(proc);
proc->rsp = add_fake_task_return(
reinterpret_cast<uintptr_t>(stack),
proc->rsp0,
proc->rsp = reinterpret_cast<uintptr_t>(stack);
proc->add_fake_task_return(
reinterpret_cast<uintptr_t>(ramdisk_process_loader));
// Arguments for iret - rip will be pushed on before these
@@ -201,8 +184,7 @@ scheduler::create_kernel_task(pid_t pid, void (*task)())
// Create an initial kernel stack space
proc->setup_kernel_stack();
proc->rsp = add_fake_task_return(
proc->rsp0, proc->rsp0,
proc->add_fake_task_return(
reinterpret_cast<uintptr_t>(task));
proc->pml4 = page_manager::get()->get_kernel_pml4();
@@ -216,6 +198,7 @@ scheduler::create_kernel_task(pid_t pid, void (*task)())
log::debug(logs::task, "Creating kernel task: pid %d pri %d", proc->pid, proc->priority);
log::debug(logs::task, " RSP0 %016lx", proc->rsp0);
log::debug(logs::task, " RSP %016lx", proc->rsp);
log::debug(logs::task, " PML4 %016lx", proc->pml4);
}
void