From a9d3bdba6f412cf1a3b4f0515f922d164cbb8585 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Tue, 18 Oct 2022 17:18:37 +0200
Subject: [PATCH] Kernel: Keep track of a task's PPID

---
 kernel/include/thread/Task.h    | 1 +
 kernel/src/sys/exec.cpp         | 2 ++
 kernel/src/thread/Scheduler.cpp | 5 +++++
 3 files changed, 8 insertions(+)

diff --git a/kernel/include/thread/Task.h b/kernel/include/thread/Task.h
index e59b9ad2..cd2dc780 100644
--- a/kernel/include/thread/Task.h
+++ b/kernel/include/thread/Task.h
@@ -18,6 +18,7 @@ struct Task
     };
 
     uint64_t id;
+    uint64_t ppid;
     Context regs;
 
     int64_t task_sleep = 0;
diff --git a/kernel/src/sys/exec.cpp b/kernel/src/sys/exec.cpp
index 4f7acfb9..74b37999 100644
--- a/kernel/src/sys/exec.cpp
+++ b/kernel/src/sys/exec.cpp
@@ -41,6 +41,8 @@ void sys_fork(Context* context)
 
     child->address_space = parent->address_space.clone();
 
+    child->ppid = parent->id;
+
     child->regs.rax = 0;
     context->rax = child->id;
 
diff --git a/kernel/src/thread/Scheduler.cpp b/kernel/src/thread/Scheduler.cpp
index 17493c6d..b3e8c746 100644
--- a/kernel/src/thread/Scheduler.cpp
+++ b/kernel/src/thread/Scheduler.cpp
@@ -102,6 +102,7 @@ void Scheduler::add_kernel_task(const char* taskname, void (*task)(void))
     ASSERT(new_task);
     new_task->user_task = false;
     new_task->id = free_tid++;
+    new_task->ppid = 0;
     new_task->regs.rip = (uint64_t)task;
     new_task->allocated_stack =
         (uint64_t)MemoryManager::get_pages(TASK_PAGES_IN_STACK); // 16 KB is enough for everyone, right?
@@ -128,6 +129,7 @@ Task* Scheduler::create_user_task()
     memset(&new_task->regs, 0, sizeof(Context));
     new_task->user_task = true;
     new_task->id = free_tid++;
+    new_task->ppid = 0;
     new_task->task_sleep = 0;
     new_task->task_time = 0;
     new_task->cpu_time = 0;
@@ -152,9 +154,11 @@ long Scheduler::load_user_task(const char* filename)
     ASSERT(new_task);
     memset(&new_task->regs, 0, sizeof(Context));
     new_task->id = free_tid++;
+    new_task->ppid = 0;
     if (!new_task->allocator.init())
     {
         delete new_task;
+        free_tid--;
         Interrupts::pop();
         return -ENOMEM;
     }
@@ -173,6 +177,7 @@ long Scheduler::load_user_task(const char* filename)
     {
         new_task->address_space.destroy();
         delete new_task;
+        free_tid--;
         ELFLoader::release_elf_image(image);
         VMM::switch_back_to_kernel_address_space();
         Interrupts::pop();