From a99a2ef34b6feb5e678d663d154cde9837708e67 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Fri, 10 Feb 2023 16:31:33 +0200
Subject: [PATCH] Added stub interpreter support

---
 Execute/Elf/BaseLoad.cpp | 58 +++++++++++++++++++++++++++++++++++++++-
 Execute/Elf/Exec.cpp     | 19 +++++++------
 include/exec.hpp         |  5 ++++
 3 files changed, 71 insertions(+), 11 deletions(-)

diff --git a/Execute/Elf/BaseLoad.cpp b/Execute/Elf/BaseLoad.cpp
index 9de940c..0575390 100644
--- a/Execute/Elf/BaseLoad.cpp
+++ b/Execute/Elf/BaseLoad.cpp
@@ -17,6 +17,51 @@ using VirtualFileSystem::NodeFlags;
 
 namespace Execute
 {
+    /* Passing arguments as a sanity check and debugging. */
+    void ELFInterpreterIPCThread(PCB *Process, char *Path, void *MemoryImage, Vector<String> NeededLibraries)
+    {
+        debug("Interpreter thread started for %s", Path);
+        // Interpreter will create an IPC with token "LOAD".
+        char UniqueToken[16] = {'L', 'O', 'A', 'D', '\0'};
+        InterProcessCommunication::IPCHandle *Handle = nullptr;
+        while (Handle == nullptr)
+        {
+            debug("Searching for IPC with token %s", UniqueToken);
+            Handle = Process->IPC->SearchByToken(UniqueToken);
+            if (Handle == nullptr)
+                debug("Failed");
+            TaskManager->Sleep(100);
+            if (Handle == nullptr)
+                debug("Retrying...");
+        }
+        debug("IPC found, sending data...");
+    RetryIPCWrite:
+        uintptr_t *TmpBuffer = new uintptr_t[0x1000];
+        *(int *)TmpBuffer = 2545;
+        InterProcessCommunication::IPCErrorCode ret = Process->IPC->Write(Handle->ID, TmpBuffer, 0x1000);
+        delete[] TmpBuffer;
+        debug("Write returned %d", ret);
+        if (ret == InterProcessCommunication::IPCErrorCode::IPCNotListening)
+        {
+            debug("IPC not listening, retrying...");
+            TaskManager->Sleep(100);
+            goto RetryIPCWrite;
+        }
+        while (1)
+            ;
+    }
+
+    PCB *InterpreterTargetProcess;
+    String *InterpreterTargetPath; /* We can't have String as a constructor :( */
+    void *InterpreterMemoryImage;
+    Vector<String> InterpreterNeededLibraries;
+    void ELFInterpreterThreadWrapper()
+    {
+        ELFInterpreterIPCThread(InterpreterTargetProcess, (char *)InterpreterTargetPath->c_str(), InterpreterMemoryImage, InterpreterNeededLibraries);
+        delete InterpreterTargetPath;
+        return;
+    }
+
     ELFBaseLoad ELFLoad(char *Path, const char **argv, const char **envp, Tasking::TaskCompatibility Compatibility)
     {
         /* We get the base name ("app.elf") */
@@ -108,7 +153,6 @@ namespace Execute
         // for (size_t i = 0; i < TO_PAGES(ElfLazyResolverSize); i++)
         // pV.Remap((void *)((uintptr_t)ElfLazyResolver + (i * PAGE_SIZE)), (void *)((uintptr_t)ElfLazyResolver + (i * PAGE_SIZE)), Memory::PTFlag::RW | Memory::PTFlag::US);
 
-        /* We prepare the ELF for execution (allocate memory, etc...) */
         ELFBaseLoad bl;
 
         switch (ELFHeader->e_type)
@@ -139,6 +183,18 @@ namespace Execute
         }
         }
 
+        if (bl.Interpreter)
+        {
+            InterpreterTargetProcess = Process;
+            InterpreterTargetPath = new String(Path); /* We store in a String because Path may get changed while outside ELFLoad(). */
+            InterpreterMemoryImage = bl.MemoryImage;
+            InterpreterNeededLibraries = bl.NeededLibraries;
+            __sync_synchronize();
+            TCB *InterpreterIPCThread = TaskManager->CreateThread(TaskManager->GetCurrentProcess(), (IP)ELFInterpreterThreadWrapper);
+            InterpreterIPCThread->Rename("ELF Interpreter IPC Thread");
+            InterpreterIPCThread->SetPriority(TaskPriority::Low);
+        }
+
         TCB *Thread = TaskManager->CreateThread(Process,
                                                 bl.InstructionPointer,
                                                 argv, envp, bl.auxv,
diff --git a/Execute/Elf/Exec.cpp b/Execute/Elf/Exec.cpp
index 373b56b..53ddf67 100644
--- a/Execute/Elf/Exec.cpp
+++ b/Execute/Elf/Exec.cpp
@@ -81,8 +81,6 @@ namespace Execute
             }
         }
 
-        Vector<char *> NeededLibraries;
-
         if (!DynamicString)
             DynamicString = StringTable;
 
@@ -137,10 +135,9 @@ namespace Execute
                             break;
                         }
 
-                        char *ReqLib = (char *)kmalloc(256);
-                        strcpy(ReqLib, (char *)((uintptr_t)ElfFile + DynamicString->sh_offset + Dynamic[i].d_un.d_ptr));
-                        debug("DT_NEEDED - Name[%ld]: %s", i, ReqLib);
-                        NeededLibraries.push_back(ReqLib);
+                        String ReqLib = (char *)((uintptr_t)ElfFile + DynamicString->sh_offset + Dynamic[i].d_un.d_val);
+                        debug("DT_NEEDED - Name[%ld]: %s", i, ReqLib.c_str());
+                        ELFBase.NeededLibraries.push_back(ReqLib);
                     }
                     else if (Dynamic[i].d_tag == DT_NULL)
                         break;
@@ -179,7 +176,11 @@ namespace Execute
             }
         }
 
-        EntryPoint = LoadELFInterpreter(ELFBase.TmpMem, pV, InterpreterPath);
+        if (strlen(InterpreterPath) > 1)
+        {
+            EntryPoint = LoadELFInterpreter(ELFBase.TmpMem, pV, InterpreterPath);
+            ELFBase.Interpreter = true;
+        }
 
         debug("Entry Point: %#lx", EntryPoint);
 
@@ -197,9 +198,7 @@ namespace Execute
         ELFBase.auxv.push_back({.archaux = {.a_type = AT_PHDR, .a_un = {.a_val = (uint64_t)ELFHeader->e_phoff}}});
 
         ELFBase.InstructionPointer = EntryPoint;
-
-        foreach (auto var in NeededLibraries)
-            kfree(var);
+        ELFBase.MemoryImage = MemoryImage;
 
         ELFBase.Success = true;
         return ELFBase;
diff --git a/include/exec.hpp b/include/exec.hpp
index 50a8322..3b7338a 100644
--- a/include/exec.hpp
+++ b/include/exec.hpp
@@ -4,6 +4,7 @@
 #include <types.h>
 
 #include <filesystem.hpp>
+#include <string.hpp>
 #include <task.hpp>
 #include <elf.h>
 
@@ -55,9 +56,13 @@ namespace Execute
     struct ELFBaseLoad
     {
         bool Success;
+        bool Interpreter;
         SpawnData sd;
         Tasking::IP InstructionPointer;
 
+        Vector<String> NeededLibraries;
+        void *MemoryImage;
+
         /* This should be deleted after copying the allocated pages to the thread
            Intended to be used only inside BaseLoad.cpp */
         Memory::MemMgr *TmpMem;