Flummi/amxmodx
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Combine prologue and epilogue code for void and non-void functions in hamsandwich trampolines.

Browse Source
This commit is contained in:
Scott Ehlert
2014-05-31 04:00:25 -05:00
parent fe52f1eeac
commit 3987085572
1 changed files with 36 additions and 153 deletions
Download Patch File Download Diff File Expand all files Collapse all files

179
dlls/hamsandwich/Trampolines.h
View File

@@ -72,28 +72,13 @@ namespace Trampolines
namespace Bytecode namespace Bytecode
{ {
/** /**
* Prologue for a void function * Prologue for a function
* Clobbers EBX and EAX
*/ */
const unsigned char codeVoidPrologue[] = { const unsigned char codePrologue[] = {
0x55, // push ebp 0x55, // push ebp
0x89, 0xE5, // mov ebp, esp 0x89, 0xE5, // mov ebp, esp
}; };
/**
* Prologue for a function that returns
* Clobbers EBX, EAX too but not after call
*/
const unsigned char codeReturnPrologue[] = {
0x55, // push ebp
0x89, 0xE5, // mov ebp, esp
};
const unsigned char codeThisReturnPrologue[] = {
0x55, // push ebp
0x89, 0xE5, // mov ebp, esp
};
/** /**
* Takes a paramter from the trampoline's stack * Takes a paramter from the trampoline's stack
* and pushes it onto the target's stack. * and pushes it onto the target's stack.
@@ -166,34 +151,17 @@ namespace Trampolines
const unsigned int codeFreeStackReplace = 2; const unsigned int codeFreeStackReplace = 2;
/** /**
* Epilogue of a simple return function * Epilogue of a simple function
*/ */
const unsigned char codeReturnEpilogue[] = { const unsigned char codeEpilogue[] = {
0x5D, // pop ebp 0x5D, // pop ebp
0xC3 // ret 0xC3 // ret
}; };
const unsigned char codeReturnEpilogueN[] = { const unsigned char codeEpilogueN[] = {
0x5D, // pop ebp 0x5D, // pop ebp
0xC2, 0xCD, 0xAB // retn 0xABCD 0xC2, 0xCD, 0xAB // retn 0xABCD
}; };
const int codeReturnEpilogueNReplace = 2; const int codeEpilogueNReplace = 2;
/**
* Epilogue of a void return function
*/
const unsigned char codeVoidEpilogue[] = {
0x5D, // pop ebp
0xC3 // ret
};
const unsigned char codeVoidEpilogueN[] = {
0x5D, // pop ebp
0xC2, 0xCD, 0xAB // retn 0xABCD
};
const int codeVoidEpilogueNReplace = 2;
const unsigned char codeBreakpoint[] = { const unsigned char codeBreakpoint[] = {
0xCC // int 3 0xCC // int 3
@@ -269,65 +237,50 @@ namespace Trampolines
}; };
/** /**
* Adds the "return prologue", pushes registers and prepares stack * Adds the prologue, pushes registers, prepares the stack
*/ */
void ReturnPrologue() void Prologue()
{ {
Append(&::Trampolines::Bytecode::codeReturnPrologue[0],sizeof(::Trampolines::Bytecode::codeReturnPrologue)); Append(&::Trampolines::Bytecode::codePrologue[0],sizeof(::Trampolines::Bytecode::codePrologue));
m_paramstart=0;
m_thiscall=0;
};
void ThisReturnPrologue()
{
this->ReturnPrologue();
m_thiscall=1;
};
/**
* Adds the void prologue pushes registers, prepares the stack
*/
void VoidPrologue()
{
Append(&::Trampolines::Bytecode::codeVoidPrologue[0],sizeof(::Trampolines::Bytecode::codeVoidPrologue));
m_paramstart=0; m_paramstart=0;
m_thiscall=0; m_thiscall=0;
}; };
/** /**
* Flags this trampoline as a thiscall trampoline, and prepares the void prologue. * Flags this trampoline as a thiscall trampoline, and prepares the prologue.
*/ */
void ThisVoidPrologue() void ThisPrologue()
{ {
this->VoidPrologue(); this->Prologue();
m_thiscall=1; m_thiscall=1;
}; };
/** /**
* Epilogue for a returning function pops registers but does not free any more of the stack! * Epilogue for a function pops registers but does not free any more of the stack!
*/ */
void ReturnEpilogue() void Epilogue()
{ {
Append(&::Trampolines::Bytecode::codeReturnEpilogue[0],sizeof(::Trampolines::Bytecode::codeReturnEpilogue)); Append(&::Trampolines::Bytecode::codeEpilogue[0],sizeof(::Trampolines::Bytecode::codeEpilogue));
}; };
/** /**
* Epilogue that also frees it's estimated stack usage. Useful for stdcall/thiscall/fastcall. * Epilogue that also frees it's estimated stack usage. Useful for stdcall/thiscall/fastcall.
*/ */
void ReturnEpilogueAndFree() void EpilogueAndFree()
{ {
this->ReturnEpilogue(m_mystack); this->Epilogue(m_mystack);
}; };
/** /**
* Return epilogue. Pops registers, and frees given amount of data from the stack. * Epilogue. Pops registers, and frees given amount of data from the stack.
* *
* @param howmuch How many bytes to free from the stack. * @param howmuch How many bytes to free from the stack.
*/ */
void ReturnEpilogue(int howmuch) void Epilogue(int howmuch)
{ {
unsigned char code[sizeof(::Trampolines::Bytecode::codeEpilogueN)];
unsigned char code[sizeof(::Trampolines::Bytecode::codeReturnEpilogueN)]; memcpy(&code[0],&::Trampolines::Bytecode::codeEpilogueN[0],sizeof(::Trampolines::Bytecode::codeEpilogueN));
memcpy(&code[0],&::Trampolines::Bytecode::codeReturnEpilogueN[0],sizeof(::Trampolines::Bytecode::codeReturnEpilogueN));
unsigned char *c=&code[0]; unsigned char *c=&code[0];
@@ -340,57 +293,11 @@ namespace Trampolines
bi.i=howmuch; bi.i=howmuch;
c+=::Trampolines::Bytecode::codeReturnEpilogueNReplace; c+=::Trampolines::Bytecode::codeEpilogueNReplace;
*c++=bi.b[0]; *c++=bi.b[0];
*c++=bi.b[1]; *c++=bi.b[1];
Append(&code[0],sizeof(::Trampolines::Bytecode::codeReturnEpilogueN)); Append(&code[0],sizeof(::Trampolines::Bytecode::codeEpilogueN));
//Append(&::Trampolines::Bytecode::codeReturnEpilogueN[0],sizeof(::Trampolines::Bytecode::codeReturnEpilogueN));
};
/**
* Void epilogue, pops registers and frees the estimated stack usage of the trampoline.
*/
void VoidEpilogueAndFree()
{
this->VoidEpilogue(m_mystack);
};
/**
* Void epilogue, pops registers, nothing else done with stack.
*/
void VoidEpilogue()
{
Append(&::Trampolines::Bytecode::codeVoidEpilogue[0],sizeof(::Trampolines::Bytecode::codeVoidEpilogue));
};
/**
* Void epilogue, pops registers, frees given amount of data off of the stack.
*
* @param howmuch How many bytes to free from the stack.
*/
void VoidEpilogue(int howmuch)
{
unsigned char code[sizeof(::Trampolines::Bytecode::codeVoidEpilogueN)];
memcpy(&code[0],&::Trampolines::Bytecode::codeVoidEpilogueN[0],sizeof(::Trampolines::Bytecode::codeVoidEpilogueN));
unsigned char *c=&code[0];
union
{
int i;
unsigned char b[4];
} bi;
bi.i=howmuch;
c+=::Trampolines::Bytecode::codeVoidEpilogueNReplace;
*c++=bi.b[0];
*c++=bi.b[1];
Append(&code[0],sizeof(::Trampolines::Bytecode::codeVoidEpilogueN));
Append(&::Trampolines::Bytecode::codeVoidEpilogueN[0],sizeof(::Trampolines::Bytecode::codeVoidEpilogueN));
}; };
/** /**
@@ -642,27 +549,13 @@ inline void *CreateGenericTrampoline(bool thiscall, bool voidcall, bool retbuf,
{ {
Trampolines::TrampolineMaker tramp; Trampolines::TrampolineMaker tramp;
if (voidcall)
{
if (thiscall) if (thiscall)
{ {
tramp.ThisVoidPrologue(); tramp.ThisPrologue();
} }
else else
{ {
tramp.VoidPrologue(); tramp.Prologue();
}
}
else
{
if (thiscall)
{
tramp.ThisReturnPrologue();
}
else
{
tramp.ReturnPrologue();
}
} }
while (paramcount) while (paramcount)
@@ -676,31 +569,21 @@ inline void *CreateGenericTrampoline(bool thiscall, bool voidcall, bool retbuf,
tramp.PushNum(reinterpret_cast<int>(extraptr)); tramp.PushNum(reinterpret_cast<int>(extraptr));
tramp.Call(callee); tramp.Call(callee);
tramp.FreeTargetStack(); tramp.FreeTargetStack();
if (voidcall)
{
#if defined(_WIN32) #if defined(_WIN32)
tramp.VoidEpilogueAndFree(); tramp.EpilogueAndFree();
#elif defined(__linux__) || defined(__APPLE__) #elif defined(__linux__) || defined(__APPLE__)
if (retbuf) if (retbuf)
{ {
tramp.VoidEpilogue(4); tramp.Epilogue(4);
} }
else else
{ {
tramp.VoidEpilogue(); tramp.Epilogue();
} }
#endif #endif
}
else
{
#if defined(_WIN32)
tramp.ReturnEpilogueAndFree();
#elif defined(__linux__) || defined(__APPLE__)
tramp.ReturnEpilogue();
#endif
}
return tramp.Finish(NULL);
return tramp.Finish(NULL);
}; };