FunctionPatcherModule/source/function_patcher.cpp

#include <coreinit/dynload.h>
#include <coreinit/cache.h>
#include <coreinit/debug.h>
#include <coreinit/memorymap.h>
#include <kernel/kernel.h>
#include "function_patcher.h"
#include "logger.h"
#include "CThread.h"

void writeDataAndFlushIC(CThread *thread, void *arg) {
    auto *data = (uint32_t *) arg;

    DCFlushRange(data, sizeof(uint32_t) * 3);

    uint32_t replace_instruction = data[0];
    uint32_t physical_address = data[1];
    uint32_t effective_address = data[2];
    DCFlushRange(&replace_instruction, 4);
    DCFlushRange(&physical_address, 4);

    DEBUG_FUNCTION_LINE_VERBOSE("Write instruction %08X to %08X [%08X] on core %d", replace_instruction, effective_address, physical_address, OSGetThreadAffinity(OSGetCurrentThread()) / 2);

    auto replace_instruction_physical = (uint32_t) & replace_instruction;

    if (replace_instruction_physical < 0x00800000 || replace_instruction_physical >= 0x01000000) {
        replace_instruction_physical = OSEffectiveToPhysical(replace_instruction_physical);
    } else {
        replace_instruction_physical = replace_instruction_physical + 0x30800000 - 0x00800000;
    }

    KernelCopyData(physical_address, replace_instruction_physical, 4);
    ICInvalidateRange((void *) (effective_address), 4);
}

void FunctionPatcherRestoreDynamicFunctions(function_replacement_data_t *replacements, uint32_t size) {
    for (uint32_t i = 0; i < size; i++) {
        function_replacement_data_t *function_data = &replacements[i];
        if (function_data->VERSION != FUNCTION_REPLACEMENT_DATA_STRUCT_VERSION) {
            OSFatal("Failed to patch function. struct version mismatch");
        }

        uint32_t targetAddrPhys = function_data->physicalAddr;
        if (function_data->library != LIBRARY_OTHER) {
            targetAddrPhys = (uint32_t) OSEffectiveToPhysical(function_data->realAddr);
        }
        if (isDynamicFunction(targetAddrPhys)) {
            DEBUG_FUNCTION_LINE("Setting alreadyPatched to false for %s because it's a dynamic function", function_data->function_name);
            function_data->alreadyPatched = 0;
        }
    }
}

void FunctionPatcherPatchFunction(function_replacement_data_t *replacements, uint32_t size) {
    for (uint32_t i = 0; i < size; i++) {
        function_replacement_data_t *function_data = &replacements[i];
        if (function_data->VERSION != FUNCTION_REPLACEMENT_DATA_STRUCT_VERSION) {
            OSFatal("Failed to patch function. struct version mismatch");
        }
        /* Patch branches to it.  */
        volatile uint32_t *space = function_data->replace_data;

        if (function_data->alreadyPatched == 1) {
            DEBUG_FUNCTION_LINE_VERBOSE("Skipping %s, its already patched\n", function_data->function_name);
            continue;
        }

        DEBUG_FUNCTION_LINE_VERBOSE("Patching %s ...", function_data->function_name);

        uint32_t physical = function_data->physicalAddr;
        auto repl_addr = (uint32_t) function_data->replaceAddr;
        auto call_addr = (uint32_t) function_data->replaceCall;

        uint32_t real_addr = function_data->virtualAddr;
        if (function_data->library != LIBRARY_OTHER) {
            real_addr = getAddressOfFunction(function_data->function_name, function_data->library);
        }

        if (!real_addr) {
            WHBLogWritef("");
            DEBUG_FUNCTION_LINE("OSDynLoad_FindExport failed for %s", function_data->function_name);
            continue;
        }

        DEBUG_FUNCTION_LINE_VERBOSE("%s is located at %08X!", function_data->function_name, real_addr);

        if (function_data->library != LIBRARY_OTHER) {
            physical = (uint32_t) OSEffectiveToPhysical(real_addr);
        }

        if (!physical) {
            WHBLogWritef("Error. Something is wrong with the physical address");
            continue;
        }

        DEBUG_FUNCTION_LINE_VERBOSE("%s physical is located at %08X!", function_data->function_name, physical);

        *(volatile uint32_t *) (call_addr) = (uint32_t)(space);

        auto targetAddr = (uint32_t) space;
        if (targetAddr < 0x00800000 || targetAddr >= 0x01000000) {
            targetAddr = (uint32_t) OSEffectiveToPhysical(targetAddr);
        } else {
            targetAddr = targetAddr + 0x30800000 - 0x00800000;
        }

        KernelCopyData(targetAddr, physical, 4);

        ICInvalidateRange((void *) (space), 4);
        DCFlushRange((void *) (space), 4);

        space++;

        // fill the restore instruction section
        function_data->realAddr = real_addr;
        function_data->restoreInstruction = space[-1];

        DEBUG_FUNCTION_LINE_VERBOSE("function_data->realAddr = %08X!", function_data->realAddr);
        DEBUG_FUNCTION_LINE_VERBOSE("function_data->restoreInstruction = %08X!", function_data->restoreInstruction);

        /*
        00808cfc 3d601234      lis        r11 ,0x1234
        00808d00 616b5678      ori        r11 ,r11 ,0x5678
        00808d04 7d6903a6      mtspr      CTR ,r11
        00808d08 4e800420      bctr
         */

        *space = 0x3d600000 | (((real_addr + 4) >> 16) & 0x0000FFFF); space++;   // lis        r11 ,0x1234
        *space = 0x616b0000 | ((real_addr + 4) & 0x0000ffff); space++;           // ori        r11 ,r11 ,0x5678
        *space = 0x7d6903a6; space++;                                            // mtspr      CTR ,r11
        *space = 0x4e800420; space++;                                            // bctr

        //setting jump back
        uint32_t replace_instr = 0x48000002 | (repl_addr & 0x03FFFFFC);

        // If the jump is too big or we want only patch for certain processes we need a trampoline
        if (repl_addr > 0x03FFFFFC || function_data->targetProcess != FP_TARGET_PROCESS_ALL) {
            auto repl_addr_test = (uint32_t) space;
            if (function_data->targetProcess != FP_TARGET_PROCESS_ALL) {
                // Only use patched function if OSGetUPID matches function_data->targetProcess
                *space = 0x3d600000 | (((uint32_t*) OSGetUPID)[0] & 0x0000FFFF); space++;               // lis        r11 ,0x0
                *space = 0x816b0000 | (((uint32_t*) OSGetUPID)[1] & 0x0000FFFF); space++;               // lwz        r11 ,0x0(r11)
                if(function_data->targetProcess == FP_TARGET_PROCESS_GAME_AND_MENU){
                    *space = 0x2c0b0000 | FP_TARGET_PROCESS_WII_U_MENU; space++;                        // cmpwi      r11 ,FP_TARGET_PROCESS_WII_U_MENU
                    *space = 0x41820000 | 0x00000020; space++;                                          // beq        myfunc
                    *space = 0x2c0b0000 | FP_TARGET_PROCESS_GAME; space++;                              // cmpwi      r11 ,FP_TARGET_PROCESS_GAME
                    *space = 0x41820000 | 0x00000018; space++;                                          // beq        myfunc
                } else {
                    *space = 0x2c0b0000 | function_data->targetProcess; space++;                        // cmpwi      r11 ,function_data->targetProcess
                    *space = 0x41820000 | 0x00000018; space++;                                          // beq        myfunc
                }
                *space = 0x3d600000 | (((real_addr + 4) >> 16) & 0x0000FFFF); space++;                  // lis        r11 ,(real_addr + 4)@hi
                *space = 0x616b0000 | ((real_addr + 4) & 0x0000ffff); space++;                          // ori        r11 ,(real_addr + 4)@lo
                *space = 0x7d6903a6; space++;                                                           // mtspr      CTR ,r11
                *space = function_data->restoreInstruction; space++;                                    //
                *space = 0x4e800420; space++;                                                           // bctr
            }
// myfunc:
            *space = 0x3d600000 | (((repl_addr) >> 16) & 0x0000FFFF); space++;                          // lis        r11 ,repl_addr@hi
            *space = 0x616b0000 | ((repl_addr) & 0x0000ffff); space++;                                  // ori        r11 ,r11 ,repl_addr@lo
            *space = 0x7d6903a6; space++;                                                               // mtspr      CTR ,r11
            *space = 0x4e800420; space++;                                                               // bctr

            // Make sure the trampoline itself is usable.
            if ((repl_addr_test & 0x03FFFFFC) != repl_addr_test) {
                OSFatal("Jump is impossible");
            }

            replace_instr = 0x48000002 | (repl_addr_test & 0x03FFFFFC);
        }

        if (space > &function_data->replace_data[FUNCTION_PATCHER_METHOD_STORE_SIZE]) {
            OSFatal("The replacement data is too long.");
        }

        DCFlushRange((void *) function_data->replace_data, FUNCTION_PATCHER_METHOD_STORE_SIZE * 4);
        ICInvalidateRange((void *) function_data->replace_data, FUNCTION_PATCHER_METHOD_STORE_SIZE * 4);

        uint32_t data[] = {
                replace_instr,
                physical,
                real_addr
        };
        CThread::runOnAllCores(writeDataAndFlushIC, data);

        function_data->alreadyPatched = 1;
        DEBUG_FUNCTION_LINE_VERBOSE("done with patching %s!", function_data->function_name);

    }
    DEBUG_FUNCTION_LINE_VERBOSE("Done with patching given functions!");

}

void FunctionPatcherRestoreFunctions(function_replacement_data_t *replacements, uint32_t size) {
    DEBUG_FUNCTION_LINE("Restoring given functions!");
    for (uint32_t i = 0; i < size; i++) {
        DEBUG_FUNCTION_LINE_VERBOSE("Restoring %s... ", replacements[i].function_name);
        if (replacements[i].restoreInstruction == 0 || replacements[i].realAddr == 0) {
            DEBUG_FUNCTION_LINE("I dont have the information for the restore =( skip");
            continue;
        }

        auto targetAddrPhys = (uint32_t) replacements[i].physicalAddr;

        if (replacements[i].library != LIBRARY_OTHER) {
            targetAddrPhys = (uint32_t) OSEffectiveToPhysical(replacements[i].realAddr);
        }

        if (isDynamicFunction(targetAddrPhys) &&
            // Other processes than the wii u menu and game one seem to keep their rpl's loaded.
            replacements[i].targetProcess != FP_TARGET_PROCESS_GAME_AND_MENU &&
            replacements[i].targetProcess != FP_TARGET_PROCESS_GAME &&
            replacements[i].targetProcess != FP_TARGET_PROCESS_WII_U_MENU
                ) {
            WHBLogPrintf("Its a dynamic function. We don't need to restore it!", replacements[i].function_name);
            replacements[i].alreadyPatched = false;
        } else {
            DEBUG_FUNCTION_LINE_VERBOSE("\nRestoring %08X to %08X [%08X]", (uint32_t) replacements[i].restoreInstruction, replacements[i].realAddr, targetAddrPhys);
            auto sourceAddr = (uint32_t) &replacements[i].restoreInstruction;

            auto sourceAddrPhys = (uint32_t) OSEffectiveToPhysical(sourceAddr);

            // These hardcoded values should be replaced with something more dynamic.
            if (sourceAddrPhys == 0 && (sourceAddr >= 0x00800000 && sourceAddr < 0x01000000)) {
                sourceAddrPhys = sourceAddr + (0x30800000 - 0x00800000);
            }

            if(sourceAddrPhys == 0){
                OSFatal("Failed to get physical address");
            }

            KernelCopyData(targetAddrPhys, sourceAddrPhys, 4);
            DEBUG_FUNCTION_LINE_VERBOSE("\nICInvalidateRange %08X", (void *) replacements[i].realAddr);
            ICInvalidateRange((void *) replacements[i].realAddr, 4);
            WHB_LOG_PRINTF_VERBOSE("done");
        }
        replacements[i].alreadyPatched = 0; // In case a
    }
    DEBUG_FUNCTION_LINE("Done with restoring given functions!");
}

bool isDynamicFunction(uint32_t physicalAddress) {
    if ((physicalAddress & 0x80000000) == 0x80000000) {
        return true;
    }
    return false;
}

rpl_handling rpl_handles[] __attribute__((section(".data"))) = {
        {LIBRARY_AVM,      "avm.rpl",      nullptr},
        {LIBRARY_CAMERA,   "camera.rpl",   nullptr},
        {LIBRARY_COREINIT, "coreinit.rpl", nullptr},
        {LIBRARY_DC,       "dc.rpl",       nullptr},
        {LIBRARY_DMAE,     "dmae.rpl",     nullptr},
        {LIBRARY_DRMAPP,   "drmapp.rpl",   nullptr},
        {LIBRARY_ERREULA,  "erreula.rpl",  nullptr},
        {LIBRARY_GX2,      "gx2.rpl",      nullptr},
        {LIBRARY_H264,     "h264.rpl",     nullptr},
        {LIBRARY_LZMA920,  "lzma920.rpl",  nullptr},
        {LIBRARY_MIC,      "mic.rpl",      nullptr},
        {LIBRARY_NFC,      "nfc.rpl",      nullptr},
        {LIBRARY_NIO_PROF, "nio_prof.rpl", nullptr},
        {LIBRARY_NLIBCURL, "nlibcurl.rpl", nullptr},
        {LIBRARY_NLIBNSS,  "nlibnss.rpl",  nullptr},
        {LIBRARY_NLIBNSS2, "nlibnss2.rpl", nullptr},
        {LIBRARY_NN_AC,    "nn_ac.rpl",    nullptr},
        {LIBRARY_NN_ACP,   "nn_acp.rpl",   nullptr},
        {LIBRARY_NN_ACT,   "nn_act.rpl",   nullptr},
        {LIBRARY_NN_AOC,   "nn_aoc.rpl",   nullptr},
        {LIBRARY_NN_BOSS,  "nn_boss.rpl",  nullptr},
        {LIBRARY_NN_CCR,   "nn_ccr.rpl",   nullptr},
        {LIBRARY_NN_CMPT,  "nn_cmpt.rpl",  nullptr},
        {LIBRARY_NN_DLP,   "nn_dlp.rpl",   nullptr},
        {LIBRARY_NN_EC,    "nn_ec.rpl",    nullptr},
        {LIBRARY_NN_FP,    "nn_fp.rpl",    nullptr},
        {LIBRARY_NN_HAI,   "nn_hai.rpl",   nullptr},
        {LIBRARY_NN_HPAD,  "nn_hpad.rpl",  nullptr},
        {LIBRARY_NN_IDBE,  "nn_idbe.rpl",  nullptr},
        {LIBRARY_NN_NDM,   "nn_ndm.rpl",   nullptr},
        {LIBRARY_NN_NETS2, "nn_nets2.rpl", nullptr},
        {LIBRARY_NN_NFP,   "nn_nfp.rpl",   nullptr},
        {LIBRARY_NN_NIM,   "nn_nim.rpl",   nullptr},
        {LIBRARY_NN_OLV,   "nn_olv.rpl",   nullptr},
        {LIBRARY_NN_PDM,   "nn_pdm.rpl",   nullptr},
        {LIBRARY_NN_SAVE,  "nn_save.rpl",  nullptr},
        {LIBRARY_NN_SL,    "nn_sl.rpl",    nullptr},
        {LIBRARY_NN_SPM,   "nn_spm.rpl",   nullptr},
        {LIBRARY_NN_TEMP,  "nn_temp.rpl",  nullptr},
        {LIBRARY_NN_UDS,   "nn_uds.rpl",   nullptr},
        {LIBRARY_NN_VCTL,  "nn_vctl.rpl",  nullptr},
        {LIBRARY_NSYSCCR,  "nsysccr.rpl",  nullptr},
        {LIBRARY_NSYSHID,  "nsyshid.rpl",  nullptr},
        {LIBRARY_NSYSKBD,  "nsyskbd.rpl",  nullptr},
        {LIBRARY_NSYSNET,  "nsysnet.rpl",  nullptr},
        {LIBRARY_NSYSUHS,  "nsysuhs.rpl",  nullptr},
        {LIBRARY_NSYSUVD,  "nsysuvd.rpl",  nullptr},
        {LIBRARY_NTAG,     "ntag.rpl",     nullptr},
        {LIBRARY_PADSCORE, "padscore.rpl", nullptr},
        {LIBRARY_PROC_UI,  "proc_ui.rpl",  nullptr},
        {LIBRARY_SNDCORE2, "sndcore2.rpl", nullptr},
        {LIBRARY_SNDUSER2, "snduser2.rpl", nullptr},
        {LIBRARY_SND_CORE, "snd_core.rpl", nullptr},
        {LIBRARY_SND_USER, "snd_user.rpl", nullptr},
        {LIBRARY_SWKBD,    "swkbd.rpl",    nullptr},
        {LIBRARY_SYSAPP,   "sysapp.rpl",   nullptr},
        {LIBRARY_TCL,      "tcl.rpl",      nullptr},
        {LIBRARY_TVE,      "tve.rpl",      nullptr},
        {LIBRARY_UAC,      "uac.rpl",      nullptr},
        {LIBRARY_UAC_RPL,  "uac_rpl.rpl",  nullptr},
        {LIBRARY_USB_MIC,  "usb_mic.rpl",  nullptr},
        {LIBRARY_UVC,      "uvc.rpl",      nullptr},
        {LIBRARY_UVD,      "uvd.rpl",      nullptr},
        {LIBRARY_VPAD,     "vpad.rpl",     nullptr},
        {LIBRARY_VPADBASE, "vpadbase.rpl", nullptr},
        {LIBRARY_ZLIB125,  "zlib125.rpl",  nullptr}
};

uint32_t getAddressOfFunction(char *functionName, function_replacement_library_type_t library) {
    uint32_t real_addr = 0;

    OSDynLoad_Module rpl_handle = nullptr;

    OSDynLoad_Error err = OS_DYNLOAD_OK;

    int32_t rpl_handles_size = sizeof rpl_handles / sizeof rpl_handles[0];

    for (int32_t i = 0; i < rpl_handles_size; i++) {
        if (rpl_handles[i].library == library) {
            if (rpl_handles[i].handle == nullptr) {
                //DEBUG_FUNCTION_LINE("Lets acquire handle for rpl: %s", rpl_handles[i].rplname);
                err = OSDynLoad_IsModuleLoaded((char *) rpl_handles[i].rplname, &rpl_handles[i].handle);
            }
            if (err != OS_DYNLOAD_OK || !rpl_handles[i].handle) {
                WHBLogWritef("%s failed to acquire %d %08X\n", rpl_handles[i].rplname, err, rpl_handles[i].handle);
                return 0;
            }
            rpl_handle = rpl_handles[i].handle;
            break;
        }
    }

    if (!rpl_handle) {
        DEBUG_FUNCTION_LINE("Failed to find the RPL handle for %s", functionName);
        return 0;
    }

    OSDynLoad_FindExport(rpl_handle, 0, functionName, reinterpret_cast<void **>(&real_addr));

    if (!real_addr) {
        DEBUG_FUNCTION_LINE("OSDynLoad_FindExport failed for %s", functionName);
        return 0;
    }

    if ((library == LIBRARY_NN_ACP) && (uint32_t)(*(volatile uint32_t *) (real_addr) & 0x48000002) == 0x48000000) {
        auto address_diff = (uint32_t)(*(volatile uint32_t *) (real_addr) & 0x03FFFFFC);
        if ((address_diff & 0x03000000) == 0x03000000) {
            address_diff |= 0xFC000000;
        }
        real_addr += (int32_t) address_diff;
        if ((uint32_t)(*(volatile uint32_t *) (real_addr) & 0x48000002) == 0x48000000) {
            return 0;
        }
    }

    return real_addr;
}


void FunctionPatcherResetLibHandles() {
    int32_t rpl_handles_size = sizeof rpl_handles / sizeof rpl_handles[0];

    for (int32_t i = 0; i < rpl_handles_size; i++) {
        if (rpl_handles[i].handle != nullptr) {
            DEBUG_FUNCTION_LINE_VERBOSE("Resetting handle for rpl: %s", rpl_handles[i].rplname);
        }
        rpl_handles[i].handle = nullptr;
        // Release handle?
    }
}