From 3d947c2a03ca37a9b326cc17eae0356ae5c39e4b Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Sun, 6 Nov 2022 03:43:12 +0200
Subject: [PATCH] Added implementation of critical thread/process

---
 Core/CrashHandler.cpp | 9 +++++++--
 KThread.cpp           | 1 +
 Tasking/Task.cpp      | 4 ++--
 include/task.hpp      | 7 +++++++
 4 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/Core/CrashHandler.cpp b/Core/CrashHandler.cpp
index 8f5089a..0c270db 100644
--- a/Core/CrashHandler.cpp
+++ b/Core/CrashHandler.cpp
@@ -117,8 +117,13 @@ namespace CrashHandler
         else
         {
             debug("Exception in user mode");
-            UserModeExceptionHandler(Frame);
-            return;
+            if (!GetCurrentCPU()->CurrentThread->Security.IsCritical)
+            {
+                UserModeExceptionHandler(Frame);
+                return;
+            }
+            else
+                EHPrint("\eFF0000Init process crashed!");
         }
 
         debug("Reading control registers...");
diff --git a/KThread.cpp b/KThread.cpp
index f4d97ee..bb01a1b 100644
--- a/KThread.cpp
+++ b/KThread.cpp
@@ -81,6 +81,7 @@ void KernelMainThread()
 
     // TODO: Untested!
     Execute::SpawnData ret = Execute::Spawn(Config.InitPath, argc, (uint64_t)argv.data());
+    ret.Thread->SetCritical(true);
     if (ret.Status != Execute::ExStatus::OK)
     {
         KPrint("\eE85230Failed to start %s! Code: %d", Config.InitPath, ret);
diff --git a/Tasking/Task.cpp b/Tasking/Task.cpp
index 34e747a..93c3676 100644
--- a/Tasking/Task.cpp
+++ b/Tasking/Task.cpp
@@ -624,12 +624,12 @@ namespace Tasking
             Thread->Registers.rsp = ((uint64_t)Thread->Stack + STACK_SIZE);
             /* We need to leave the libc's crt to make a syscall when the Thread is exited or we are going to get GPF or PF exception. */
             for (uint64_t i = 0; i < TO_PAGES(STACK_SIZE); i++)
-                Memory::Virtual(Parent->PageTable).Map((void *)((uint64_t)Thread->Stack + (i * PAGE_SIZE)), (void *)((uint64_t)Thread->Stack + (i * PAGE_SIZE)), Memory::PTFlag::US);
+                Memory::Virtual(Parent->PageTable).Map((void *)((uint64_t)Thread->Stack + (i * PAGE_SIZE)), (void *)((uint64_t)Thread->Stack + (i * PAGE_SIZE)), Memory::PTFlag::RW | Memory::PTFlag::US);
 
             if (!Memory::Virtual(Parent->PageTable).Check((void *)Offset, Memory::PTFlag::US))
             {
                 error("Offset is not user accessible");
-                Memory::Virtual(Parent->PageTable).Map((void *)Offset, (void *)Offset, Memory::PTFlag::RW | Memory::PTFlag::US);
+                Memory::Virtual(Parent->PageTable).Map((void *)Offset, (void *)Offset, Memory::PTFlag::RW | Memory::PTFlag::US); // We try one more time.
             }
 #elif defined(__i386__)
 #elif defined(__aarch64__)
diff --git a/include/task.hpp b/include/task.hpp
index 6049c96..2c6ccea 100644
--- a/include/task.hpp
+++ b/include/task.hpp
@@ -60,6 +60,7 @@ namespace Tasking
     {
         TaskTrustLevel TrustLevel;
         Token UniqueToken;
+        bool IsCritical;
     };
 
     struct TaskInfo
@@ -117,6 +118,12 @@ namespace Tasking
         }
 
         int GetExitCode() { return ExitCode; }
+
+        void SetCritical(bool critical)
+        {
+            trace("Setting criticality of thread %s to %s", Name, critical ? "true" : "false");
+            Security.IsCritical = critical;
+        }
     };
 
     struct PCB