From a1672a33d775dec91a33b7efa362e02189cc9e25 Mon Sep 17 00:00:00 2001
From: J Reece Wilson <me@reece.sx>
Date: Sat, 29 Jun 2024 16:06:42 +0100
Subject: [PATCH] [*] Linux alternative dynamic loader: AuProcess main process
 path has to be pulled from the procmap instead of arg[0]

---
 Source/AuRTEntrypoint.cpp             |  2 +-
 Source/CmdLine/AuCmdLinePlatform.cpp  |  3 +++
 Source/Process/AuPaths.cpp            | 37 ++++++++++++++++++---------
 Source/Process/AuProcessMap.Linux.cpp | 37 ++++++++++++++++++++++-----
 4 files changed, 60 insertions(+), 19 deletions(-)

diff --git a/Source/AuRTEntrypoint.cpp b/Source/AuRTEntrypoint.cpp
index 07c0c6ac..9da0334e 100644
--- a/Source/AuRTEntrypoint.cpp
+++ b/Source/AuRTEntrypoint.cpp
@@ -79,6 +79,7 @@ static void Init()
     AuProcess::WarmStartupCaches();
 
     Aurora::Threading::InitSleep();
+    Aurora::CmdLine::Init();
     Aurora::Process::InitProcess();
     Aurora::SWInfo::InitSwInfo();
 
@@ -99,7 +100,6 @@ static void Init()
     Aurora::Telemetry::Init();
     Aurora::Debug::InitDebug();
     Aurora::Locale::Init();
-    Aurora::CmdLine::Init();
     Aurora::Processes::Init();
     Aurora::Hashing::InitHashing();
     Aurora::Async::InitAsync();
diff --git a/Source/CmdLine/AuCmdLinePlatform.cpp b/Source/CmdLine/AuCmdLinePlatform.cpp
index 33792299..53216d53 100644
--- a/Source/CmdLine/AuCmdLinePlatform.cpp
+++ b/Source/CmdLine/AuCmdLinePlatform.cpp
@@ -32,6 +32,8 @@ namespace Aurora::CmdLine
     }
 
 #if defined(AURORA_IS_POSIX_DERIVED)
+    AuString gHackLoader;
+
     static AuList<AuString> GetProcFSCmdString()
     {
         AuList<AuString> args;
@@ -67,6 +69,7 @@ namespace Aurora::CmdLine
         {
             if (AuStringContains(args[0], "ld-Aurora"))
             {
+                gHackLoader = args[0];
                 args.erase(args.begin());
             }
         }
diff --git a/Source/Process/AuPaths.cpp b/Source/Process/AuPaths.cpp
index ab75a5d8..a362c955 100644
--- a/Source/Process/AuPaths.cpp
+++ b/Source/Process/AuPaths.cpp
@@ -18,6 +18,21 @@
 
 namespace Aurora::Process
 {
+    static AuString gCachedModule, gCachedPartialPath, gCachedFullPath;
+    static AuInitOnce gInitOnce;
+
+    void ForceReplacePathHack(const AuString &path)
+    {
+        static AuInitOnce gInitOnce2;
+        gInitOnce2.Call([&]()
+        {
+            AuResetMember(gCachedModule);
+            AuResetMember(gCachedPartialPath);
+            AuResetMember(gCachedFullPath, path);
+            AuResetMember(gInitOnce);
+        });
+    }
+
     AUKN_SYM bool GetWorkingDirectory(AuString &path)
     {
     #if !defined(AURORA_IS_MODERNNT_DERIVED) 
@@ -188,9 +203,6 @@ namespace Aurora::Process
 
     static bool GetModulePath(const AuString *&module, const AuString *&partialPath, const AuString *&fullPath)
     {
-        static AuString cachedModule, cachedPartialPath, cachedFullPath;
-        static AuInitOnce gInitOnce;
-        
         if (!AuThreading::InitOnceLocker::TryLock(&gInitOnce, true))
         {
             gInitOnce.Wait();
@@ -203,17 +215,18 @@ namespace Aurora::Process
             {
                 char spitter;
 
-                if (GetModulePathSlow(cachedFullPath, spitter))
+                if (gCachedFullPath.size() ||
+                    GetModulePathSlow(gCachedFullPath, spitter))
                 {
-                    auto indexA = cachedFullPath.find_last_of(spitter);
+                    auto indexA = gCachedFullPath.find_last_of(spitter);
                     if (indexA != AuString::npos)
                     {
-                        cachedModule      = cachedFullPath.substr(indexA + 1);
-                        cachedPartialPath = cachedFullPath.substr(0, indexA);
+                        gCachedModule      = gCachedFullPath.substr(indexA + 1);
+                        gCachedPartialPath = gCachedFullPath.substr(0, indexA);
 
-                        if (!cachedPartialPath.ends_with(AuFS::kPathSplitter))
+                        if (!gCachedPartialPath.ends_with(AuFS::kPathSplitter))
                         {
-                            cachedPartialPath += AuFS::kPathSplitter;
+                            gCachedPartialPath += AuFS::kPathSplitter;
                         }
                     }
                     else
@@ -240,9 +253,9 @@ namespace Aurora::Process
             return false;
         }
 
-        module      = &cachedModule;
-        fullPath    = &cachedFullPath;
-        partialPath = &cachedPartialPath;
+        module      = &gCachedModule;
+        fullPath    = &gCachedFullPath;
+        partialPath = &gCachedPartialPath;
         return true;
     }
 
diff --git a/Source/Process/AuProcessMap.Linux.cpp b/Source/Process/AuProcessMap.Linux.cpp
index f29648f1..b1f2a953 100644
--- a/Source/Process/AuProcessMap.Linux.cpp
+++ b/Source/Process/AuProcessMap.Linux.cpp
@@ -18,8 +18,15 @@
     using Elf_Shdr = Elf32_Shdr;
 #endif
 
+namespace Aurora::CmdLine
+{
+    extern AuString gHackLoader;
+}
+
 namespace Aurora::Process
 {
+    void ForceReplacePathHack(const AuString &path);
+
     void InitProcessMapLinux()
     {
 
@@ -44,10 +51,13 @@ namespace Aurora::Process
                 fileName = *optProcessPath;
             }
         }
-
-        if (!AuIOFS::FileExists(fileName))
+        else
         {
-            return 0;
+            if (!AuIOFS::FileExists(fileName))
+            {
+                // NO FILE linux-vdso.so.1
+                return 0;
+            }
         }
 
         AuList<AuTuple<AuUInt, AuUInt, AuUInt, AuUInt>> sections;
@@ -124,16 +134,32 @@ namespace Aurora::Process
                 name = kSectionNameFile;
             }
 
+            AuOptional<const AuString &> optProcessPath;
+            if (AuCmdLine::gHackLoader.size())
+            {
+                optProcessPath = GetProcessFullPath();
+            }
+
             if (name.size())
             {
                 bIsSpecialFile = AuIOFS::FileExists(name);
 
                 if (bIsSpecialFile)
                 {
-                    for (const auto &[uBaseAddress, pathSectionPair] : gModuleMap)
+                    for (auto &[uBaseAddress, pathSectionPair] : gModuleMap)
                     {
                         if (uBaseAddress == base)
                         {
+                            if (optProcessPath)
+                            {
+                                if (AuGet<0>(pathSectionPair) == optProcessPath.Value())
+                                {
+                                    ForceReplacePathHack(name);
+                                    AuGet<0>(pathSectionPair) = name;
+                                    AuResetMember(optProcessPath);
+                                }
+                            }
+
                             return;
                         }
 
@@ -268,8 +294,7 @@ namespace Aurora::Process
 
             object->SetOffset(strtab.sh_offset);
             if (!object->Read(AuMemoryViewStreamWrite(AuMemoryViewWrite(strHeap.data(),
-                                                                        strHeap.size()
-                                                                        ),
+                                                                        strHeap.size()),
                                                       read)))
             {
                 SysPushErrorIO();