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[kernel] Add userspace threading

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Implement the syscalls necessary for threads to create other threads in
their same process. This involved rearranging a number of syscalls, as
well as implementing object_wait and a basic implementation of a
process' list of handles.
This commit is contained in:
Justin C. Miller
2020-07-26 16:02:38 -07:00
parent 4cf222a5bb
commit ae3290c53d
22 changed files with 481 additions and 255 deletions
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101
src/kernel/objects/thread.cpp
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@@ -1,11 +1,13 @@
#include "j6/signals.h"
#include "log.h"
#include "objects/thread.h"
#include "objects/process.h"
#include "scheduler.h"
extern "C" void kernel_to_user_trampoline();
static constexpr j6_signal_t thread_default_signals = 0;
thread::thread(process &parent, uint8_t pri) :
thread::thread(process &parent, uint8_t pri, bool user) :
kobject(kobject::type::thread, thread_default_signals),
m_parent(parent),
m_state(state::loading),
@@ -16,6 +18,22 @@ thread::thread(process &parent, uint8_t pri) :
TCB *tcbp = tcb();
tcbp->pml4 = parent.pml4();
tcbp->priority = pri;
setup_kernel_stack();
set_state(state::ready);
}
thread::thread(process &parent, uint8_t pri, uintptr_t rsp0) :
kobject(kobject::type::thread, thread_default_signals),
m_parent(parent),
m_state(state::loading),
m_wait_type(wait_type::none),
m_wait_data(0),
m_wait_obj(0)
{
TCB *tcbp = tcb();
tcbp->pml4 = parent.pml4();
tcbp->priority = pri;
tcbp->rsp0 = rsp0;
set_state(state::ready);
}
@@ -51,7 +69,8 @@ thread::wake_on_signals(kobject *obj, j6_signal_t signals)
return false;
m_wait_type = wait_type::none;
m_wait_data = j6_status_ok;
m_wait_result = j6_status_ok;
m_wait_data = signals;
m_wait_obj = obj->koid();
set_state(state::ready);
return true;
@@ -65,7 +84,8 @@ thread::wake_on_time(uint64_t now)
return false;
m_wait_type = wait_type::none;
m_wait_data = j6_status_ok;
m_wait_result = j6_status_ok;
m_wait_data = now;
m_wait_obj = 0;
set_state(state::ready);
return true;
@@ -75,7 +95,8 @@ void
thread::wake_on_result(kobject *obj, j6_status_t result)
{
m_wait_type = wait_type::none;
m_wait_data = result;
m_wait_result = result;
m_wait_data = 0;
m_wait_obj = obj->koid();
set_state(state::ready);
}
@@ -86,5 +107,77 @@ thread::exit(uint32_t code)
m_return_code = code;
set_state(state::exited);
clear_state(state::ready);
assert_signal(j6_signal_thread_exit);
}
void
thread::add_thunk_kernel(uintptr_t rip)
{
m_tcb.rsp -= sizeof(uintptr_t) * 7;
uintptr_t *stack = reinterpret_cast<uintptr_t*>(m_tcb.rsp);
stack[6] = rip; // return rip
stack[5] = m_tcb.rsp0; // rbp
stack[4] = 0xbbbbbbbb; // rbx
stack[3] = 0x12121212; // r12
stack[2] = 0x13131313; // r13
stack[1] = 0x14141414; // r14
stack[0] = 0x15151515; // r15
}
void
thread::add_thunk_user(uintptr_t rip)
{
m_tcb.rsp -= sizeof(uintptr_t) * 8;
uintptr_t *stack = reinterpret_cast<uintptr_t*>(m_tcb.rsp);
stack[7] = rip; // return rip in rcx
stack[6] = m_tcb.rsp3; // rbp
stack[5] = 0xbbbbbbbb; // rbx
stack[4] = 0x00000200; // r11 sets RFLAGS
stack[3] = 0x12121212; // r12
stack[2] = 0x13131313; // r13
stack[1] = 0x14141414; // r14
stack[0] = 0x15151515; // r15
static const uintptr_t trampoline =
reinterpret_cast<uintptr_t>(kernel_to_user_trampoline);
add_thunk_kernel(trampoline);
}
void
thread::setup_kernel_stack()
{
constexpr size_t initial_stack_size = 0x1000;
constexpr unsigned null_frame_entries = 2;
constexpr size_t null_frame_size = null_frame_entries * sizeof(uint64_t);
void *stack_bottom = kutil::kalloc(initial_stack_size);
kutil::memset(stack_bottom, 0, initial_stack_size);
log::debug(logs::memory, "Created kernel stack at %016lx size 0x%lx",
stack_bottom, initial_stack_size);
void *stack_top =
kutil::offset_pointer(stack_bottom,
initial_stack_size - null_frame_size);
uint64_t *null_frame = reinterpret_cast<uint64_t*>(stack_top);
for (unsigned i = 0; i < null_frame_entries; ++i)
null_frame[i] = 0;
m_tcb.kernel_stack_size = initial_stack_size;
m_tcb.kernel_stack = reinterpret_cast<uintptr_t>(stack_bottom);
m_tcb.rsp0 = reinterpret_cast<uintptr_t>(stack_top);
m_tcb.rsp = m_tcb.rsp0;
}
thread *
thread::create_idle_thread(process &kernel, uint8_t pri, uintptr_t rsp0)
{
thread *idle = new thread(kernel, pri, rsp0);
idle->set_state(thread::state::constant);
log::info(logs::task, "Created idle thread as koid %llx", idle->koid());
return idle;
}