Yay, the nasty SourceHook bug is finally fixed!

--HG--
extra : convert_revision : svn%3Ac2935e3e-5518-0410-8daf-afa5dab7d4e3/trunk%4087

sourcehook/sourcehook.cpp

@@ -5,6 +5,7 @@
 * License: zlib/libpng
 *
 * Author(s): Pavol "PM OnoTo" Marko
+* Contributors: Scott "Damaged Soul" Ehlert
 * ============================
 */
 
@@ -299,6 +300,13 @@ namespace SourceHook
 		if (hookman == m_HookMans.end())
 			return false;
 
+		if (IsBadReadPtr(reinterpret_cast<char*>(adjustediface) + tmp.vtbl_offs, sizeof(char)))
+		{
+			hookman->vfnptrs.clear();
+			hookman->func(HA_Unregister, NULL);
+			return true;
+		}
+
 		void **cur_vtptr = *reinterpret_cast<void***>(
 			reinterpret_cast<char*>(adjustediface) + tmp.vtbl_offs);
 		void *cur_vfnptr = reinterpret_cast<void*>(cur_vtptr + tmp.vtbl_idx);
@@ -465,6 +473,38 @@ namespace SourceHook
 		}
 	}
 
+#if __linux__
+	// Windows has an implentation for this already, but Linux does not :(
+	static bool CSourceHookImpl::IsBadReadPtr(const void *ptr, size_t len)
+	{
+		void(*prevHandler)(int sig);
+		g_BadReadCalled = true;
+
+		if (setjmp(g_BadReadJmpBuffer))
+			return true;
+
+		prevHandler = signal(SIGSEGV, BadReadHandler);
+
+		volatile const char *p = reinterpret_cast<const char*>(ptr);
+		char dummy;
+
+		for (size_t i = 0; i < len; i++)
+			dummy = p[i];
+
+		g_BadReadCalled = false;
+
+		signal(SIGSEGV, prevHandler);
+
+		return false;
+	}
+
+	static void CSourceHookImpl::BadReadHandler(int sig)
+	{
+		if (m_BadReadCalled)
+			longjmp(m_BadReadJmpBuf, 1);
+	}
+#endif
+
 	CSourceHookImpl::HookManInfoList::iterator CSourceHookImpl::FindHookMan(HookManInfoList::iterator begin,
 		HookManInfoList::iterator end, const char *proto, int vtblofs, int vtblidx)
 	{

sourcehook/sourcehook_impl.h

@@ -13,6 +13,11 @@
 
 #include "sourcehook.h"
 
+#ifdef __linux__
+#include <signal.h>
+#include <setjmp.h>
+#endif
+
 // Set this to 1 to enable runtime code generation (faster)
 #define SH_RUNTIME_CODEGEN 1
 
@@ -77,6 +82,22 @@ namespace SourceHook
 		void RemoveCallClassPatch(CallClassInfo &cc, int vtbl_offs, int vtbl_idx);
 		void RemoveCallClassPatches(void *ifaceptr, int vtbl_offs, int vtbl_idx);
 
+#ifdef __linux__
+		/**
+		*	@brief Checks to see if a memory value can be read from a given pointer.
+		*
+		*	@return True if the value can be read and false if it cannot.
+		*
+		*	@param ptr The pointer to the memory value.
+		*	@param len The length of the memory value to be read from the pointer.
+		*/
+		static bool IsBadReadPtr(const void *ptr, size_t len);
+		static void BadReadHandler(int sig);
+
+		bool m_BadReadCalled;
+		jmp_buf m_BadReadJmpBuf;
+#endif
+
 		META_RES m_Status, m_PrevRes, m_CurRes;
 		const void *m_OrigRet;
 		const void *m_OverrideRet;

sourcemm/changelog.txt

@@ -13,6 +13,7 @@
  - Fixed "meta clear" not unloading all plugins.
  - Fixed Metamod:Source loading plugins with a higher current API version.
  - Fixed whitespace being parsed in metaplugins.ini.
+ - Fixed bug where SourceHook tried to patch already destroyed/unavailable memory.
  - Bumped Plugin API version to 6.
 
 2005/05/06 1.00-RC1: