From 5de0a3972c4aced825a6cff3c4e2d929e0c5f842 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Fri, 4 Nov 2022 05:32:27 +0200
Subject: [PATCH] Added usermode process creation (currently broken)

---
 Execute/Parse.cpp | 32 +++++++++++++++++++-
 Execute/Spawn.cpp | 76 +++++++++++++++++++++++++++++++++++++++++++++--
 KThread.cpp       |  6 ++--
 include/exec.hpp  | 22 +++++++++++++-
 4 files changed, 130 insertions(+), 6 deletions(-)

diff --git a/Execute/Parse.cpp b/Execute/Parse.cpp
index 1c91b312..3544ef5a 100644
--- a/Execute/Parse.cpp
+++ b/Execute/Parse.cpp
@@ -1,6 +1,36 @@
 #include <exec.hpp>
 
+#include "../kernel.h"
+#include "../Fex.hpp"
+
 namespace Execute
 {
-    
+    BinaryType GetBinaryType(char *Path)
+    {
+        BinaryType Type = BinaryType::BinTypeInvalid;
+        FileSystem::FILE *ExFile = vfs->Open(Path);
+
+        if (ExFile->Status == FileSystem::FileStatus::OK)
+        {
+            if (ExFile->Node->Flags == FileSystem::NodeFlags::FS_FILE)
+            {
+                Fex *FexHdr = (Fex *)ExFile->Node->Address;
+                if (FexHdr->Magic[0] == 'F' && FexHdr->Magic[1] == 'E' && FexHdr->Magic[2] == 'X' && FexHdr->Magic[3] == '\0')
+                {
+                    if (FexHdr->Type == FexFormatType::FexFormatType_Executable)
+                    {
+                        Type = BinaryType::BinTypeFex;
+                        goto Exit;
+                    }
+                }
+
+                /* ... */
+
+                Type = BinaryType::BinTypeUnknown;
+            }
+        }
+    Exit:
+        vfs->Close(ExFile);
+        return Type;
+    }
 }
diff --git a/Execute/Spawn.cpp b/Execute/Spawn.cpp
index 4baf0621..61385343 100644
--- a/Execute/Spawn.cpp
+++ b/Execute/Spawn.cpp
@@ -1,9 +1,81 @@
 #include <exec.hpp>
 
+#include <memory.hpp>
+#include <lock.hpp>
+#include <cwalk.h>
+
+#include "../kernel.h"
+#include "../Fex.hpp"
+
+using namespace Tasking;
+
 namespace Execute
 {
-    ExStatus Spawn(char *Path, uint64_t Arg0, uint64_t Arg1)
+    SpawnData Spawn(char *Path, uint64_t Arg0, uint64_t Arg1)
     {
-        return ExStatus::Unknown;
+        SpawnData ret = {.Status = ExStatus::Unknown,
+                         .Process = nullptr,
+                         .Thread = nullptr};
+        FileSystem::FILE *ExFile = vfs->Open(Path);
+        if (ExFile->Status == FileSystem::FileStatus::OK)
+        {
+            if (ExFile->Node->Flags == FileSystem::NodeFlags::FS_FILE)
+            {
+                BinaryType Type = GetBinaryType(Path);
+                switch (Type)
+                {
+                case BinaryType::BinTypeFex:
+                {
+                    Fex *FexHdr = (Fex *)ExFile->Node->Address;
+                    if (FexHdr->Magic[0] == 'F' && FexHdr->Magic[1] == 'E' && FexHdr->Magic[2] == 'X' && FexHdr->Magic[3] == '\0')
+                    {
+                        if (FexHdr->Type == FexFormatType::FexFormatType_Executable)
+                        {
+                            const char *BaseName;
+                            cwk_path_get_basename(Path, &BaseName, nullptr);
+                            PCB *Process = TaskManager->CreateProcess(TaskManager->GetCurrentProcess(), BaseName, TaskTrustLevel::User);
+
+                            void *BaseImage = KernelAllocator.RequestPages(TO_PAGES(ExFile->Node->Length));
+                            memcpy(BaseImage, (void *)ExFile->Node->Address, ExFile->Node->Length);
+
+                            for (uint64_t i = 0; i < TO_PAGES(ExFile->Node->Length); i++)
+                                Memory::Virtual(Process->PageTable).Map((void *)((uint64_t)BaseImage + (i * PAGE_SIZE)), (void *)((uint64_t)BaseImage + (i * PAGE_SIZE)), Memory::PTFlag::US);
+
+                            TCB *Thread = TaskManager->CreateThread(Process,
+                                                                    (IP)FexHdr->Pointer,
+                                                                    Arg0, Arg1,
+                                                                    (IPOffset)BaseImage,
+                                                                    TaskArchitecture::x64,
+                                                                    TaskCompatibility::Native);
+                            ret.Process = Process;
+                            ret.Thread = Thread;
+                            ret.Status = ExStatus::OK;
+                            goto Exit;
+                        }
+                    }
+                    ret.Status = ExStatus::InvalidFileHeader;
+                    goto Exit;
+                }
+                default:
+                    ret.Status = ExStatus::Unsupported;
+                    goto Exit;
+                }
+                goto Exit;
+            }
+        }
+        else if (ExFile->Status == FileSystem::FileStatus::NOT_FOUND)
+        {
+            ret.Status = ExStatus::InvalidFilePath;
+            goto Exit;
+        }
+        else
+        {
+            ret.Status = ExStatus::InvalidFile;
+            goto Exit;
+        }
+
+    Exit:
+        vfs->Close(ExFile);
+        return ret;
     }
 }
diff --git a/KThread.cpp b/KThread.cpp
index 3d918aef..a10cb936 100644
--- a/KThread.cpp
+++ b/KThread.cpp
@@ -79,13 +79,15 @@ void KernelMainThread()
     argc = argv.size() - 1;
 
     // TODO: Untested!
-    Execute::ExStatus ret = Execute::Spawn(Config.InitPath, argc, (uint64_t)argv.data());
-    if (ret != Execute::ExStatus::OK)
+    Execute::SpawnData ret = Execute::Spawn(Config.InitPath, argc, (uint64_t)argv.data());
+    if (ret.Status != Execute::ExStatus::OK)
     {
         KPrint("\eE85230Failed to start %s! Code: %d", Config.InitPath, ret);
         CPU::Halt(true);
     }
     TaskManager->GetCurrentThread()->SetPriority(1);
+    TaskManager->WaitForThread(ret.Thread);
+    KPrint("\eE85230Userspace process exited with code %d", ret.Thread->GetExitCode());
     CPU::Halt(true);
 }
 
diff --git a/include/exec.hpp b/include/exec.hpp
index b7a7d90f..118b3456 100644
--- a/include/exec.hpp
+++ b/include/exec.hpp
@@ -3,12 +3,24 @@
 
 #include <types.h>
 
+#include <task.hpp>
+
 namespace Execute
 {
+    enum BinaryType
+    {
+        BinTypeInvalid,
+        BinTypeFex,
+        BinTypeElf,
+        BinTypePE,
+        BinTypeUnknown
+    };
+
     enum ExStatus
     {
         OK,
         Unknown,
+        Unsupported,
         InvalidFile,
         InvalidFileFormat,
         InvalidFileHeader,
@@ -17,7 +29,15 @@ namespace Execute
         InvalidFilePath
     };
 
-    ExStatus Spawn(char *Path, uint64_t Arg0, uint64_t Arg1);
+    struct SpawnData
+    {
+        ExStatus Status;
+        Tasking::PCB *Process;
+        Tasking::TCB *Thread;
+    };
+
+    BinaryType GetBinaryType(char *Path);
+    SpawnData Spawn(char *Path, uint64_t Arg0, uint64_t Arg1);
 }
 
 #endif // !__FENNIX_KERNEL_FILE_EXECUTE_H__