From 165b8ed893fe7eb3a514e01b5f7ceef01d806666 Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@alliedmods.net>
Date: Fri, 16 Feb 2007 04:16:31 +0000
Subject: [PATCH] fixed a serious potential bug with swapping plugins to debug
 mode, leaving stale function pointers without plugin removal

--HG--
extra : convert_revision : svn%3A39bc706e-5318-0410-9160-8a85361fbb7c/trunk%40508
---
 core/vm/sp_vm_basecontext.cpp | 35 ++++++++++++++++++++++++++++-------
 core/vm/sp_vm_basecontext.h   |  2 +-
 core/vm/sp_vm_function.cpp    |  2 ++
 core/vm/sp_vm_function.h      |  9 +++++++++
 4 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/core/vm/sp_vm_basecontext.cpp b/core/vm/sp_vm_basecontext.cpp
index 0107045b..302fb186 100644
--- a/core/vm/sp_vm_basecontext.cpp
+++ b/core/vm/sp_vm_basecontext.cpp
@@ -66,14 +66,19 @@ BaseContext::BaseContext(sp_context_t *_ctx)
 	}
 }
 
-void BaseContext::FlushFunctionCache()
+void BaseContext::FlushFunctionCache(bool remove)
 {
 	if (m_pub_funcs)
 	{
 		for (uint32_t i=0; i<ctx->plugin->info.publics_num; i++)
 		{
-			delete m_pub_funcs[i];
-			m_pub_funcs[i] = NULL;
+			if (remove)
+			{
+				delete m_pub_funcs[i];
+				m_pub_funcs[i] = NULL;
+			} else if (m_pub_funcs[i]) {
+				m_pub_funcs[i]->Invalidate();
+			}
 		}
 	}
 
@@ -81,15 +86,20 @@ void BaseContext::FlushFunctionCache()
 	{
 		for (unsigned int i=0; i<m_funcsnum; i++)
 		{
-			delete m_priv_funcs[i];
-			m_priv_funcs[i] = NULL;
+			if (remove)
+			{
+				delete m_priv_funcs[i];
+				m_priv_funcs[i] = NULL;
+			} else if (m_priv_funcs[i]) {
+				m_priv_funcs[i]->Invalidate();
+			}
 		}
 	}
 }
 
 BaseContext::~BaseContext()
 {
-	FlushFunctionCache();
+	FlushFunctionCache(true);
 	delete [] m_pub_funcs;
 	m_pub_funcs = NULL;
 	delete [] m_priv_funcs;
@@ -105,7 +115,7 @@ void BaseContext::SetContext(sp_context_t *_ctx)
 	ctx = _ctx;
 	ctx->context = this;
 	ctx->dbreak = GlobalDebugBreak;
-	FlushFunctionCache();
+	FlushFunctionCache(false);
 }
 
 IVirtualMachine *BaseContext::GetVirtualMachine()
@@ -850,6 +860,8 @@ IPluginFunction *BaseContext::GetFunctionById(funcid_t func_id)
 		{
 			m_pub_funcs[func_id] = new CFunction(ctx->publics[func_id].code_offs, this);
 			pFunc = m_pub_funcs[func_id];
+		} else if (pFunc->IsInvalidated()) {
+			pFunc->Set(ctx->publics[func_id].code_offs, this);
 		}
 	} else {
 		/* :TODO: currently not used */
@@ -892,6 +904,15 @@ IPluginFunction *BaseContext::GetFunctionByName(const char *public_name)
 			m_pub_funcs[index] = new CFunction(pub->code_offs, this);
 		}
 		pFunc = m_pub_funcs[index];
+	} else if (pFunc->IsInvalidated()) {
+		sp_public_t *pub = NULL;
+		GetPublicByIndex(index, &pub);
+		if (pub)
+		{
+			pFunc->Set(pub->code_offs, this);
+		} else {
+			pFunc = NULL;
+		}
 	}
 
 	return pFunc;
diff --git a/core/vm/sp_vm_basecontext.h b/core/vm/sp_vm_basecontext.h
index 232a7967..4c001a54 100644
--- a/core/vm/sp_vm_basecontext.h
+++ b/core/vm/sp_vm_basecontext.h
@@ -79,7 +79,7 @@ namespace SourcePawn
 		void SetContext(sp_context_t *_ctx);
 	private:
 		void SetErrorMessage(const char *msg, va_list ap);
-		void FlushFunctionCache();
+		void FlushFunctionCache(bool remove);
 	private:
 		sp_context_t *ctx;
 #if defined SOURCEMOD_BUILD
diff --git a/core/vm/sp_vm_function.cpp b/core/vm/sp_vm_function.cpp
index 04ce7a23..c4fc339f 100644
--- a/core/vm/sp_vm_function.cpp
+++ b/core/vm/sp_vm_function.cpp
@@ -25,6 +25,7 @@ void CFunction::Set(uint32_t code_addr, IPluginContext *plugin)
 	m_pContext = plugin;
 	m_curparam = 0;
 	m_errorstate = SP_ERROR_NONE;
+	m_Invalid = false;
 }
 
 int CFunction::CallFunction(const cell_t *params, unsigned int num_params, cell_t *result)
@@ -46,6 +47,7 @@ CFunction::CFunction(uint32_t code_addr, IPluginContext *plugin) :
 	m_codeaddr(code_addr), m_pContext(plugin), m_curparam(0), 
 	m_errorstate(SP_ERROR_NONE)
 {
+	m_Invalid = false;
 }
 
 int CFunction::PushCell(cell_t cell)
diff --git a/core/vm/sp_vm_function.h b/core/vm/sp_vm_function.h
index b61a51fa..2eaaf229 100644
--- a/core/vm/sp_vm_function.h
+++ b/core/vm/sp_vm_function.h
@@ -46,6 +46,14 @@ public:
 	virtual void Cancel();
 	virtual int CallFunction(const cell_t *params, unsigned int num_params, cell_t *result);
 	virtual IPluginContext *GetParentContext();
+	inline bool IsInvalidated()
+	{
+		return m_Invalid;
+	}
+	inline void Invalidate()
+	{
+		m_Invalid = true;
+	}
 public:
 	void Set(uint32_t code_addr, IPluginContext *plugin);
 private:
@@ -63,6 +71,7 @@ private:
 	unsigned int m_curparam;
 	int m_errorstate;
 	CFunction *m_pNext;
+	bool m_Invalid;
 };
 
 #endif //_INCLUDE_SOURCEMOD_BASEFUNCTION_H_