test_pid_patch.c

#include <string.h>
#include <stdio.h>

#include <switch.h>

static Handle g_port;
static uint64_t g_procID;

#define MODULE_HBL 111

void threadFunc(void* ctx)
{
    Handle session;
    Result rc;

    rc = svcWaitSynchronizationSingle(g_port, -1);
    if (R_FAILED(rc))
        fatalSimple(MAKERESULT(MODULE_HBL, 22));

    rc = svcAcceptSession(&session, g_port);
    if (R_FAILED(rc))
        fatalSimple(MAKERESULT(MODULE_HBL, 14));

    s32 idx = 0;
    rc = svcReplyAndReceive(&idx, &session, 1, 0, -1);
    if (R_FAILED(rc))
        fatalSimple(MAKERESULT(MODULE_HBL, 15));

    IpcParsedCommand ipc;
    rc = ipcParse(&ipc);
    if (R_FAILED(rc))
        fatalSimple(MAKERESULT(MODULE_HBL, 16));

    if (!ipc.HasPid)
        fatalSimple(MAKERESULT(MODULE_HBL, 17));

    g_procID = ipc.Pid;
    svcCloseHandle(session);
}

void getOwnProcessID(uint32_t fake_pid)
{
    static Thread t;
    Result rc;

    rc = threadCreate(&t, &threadFunc, NULL, 0x1000, 0x20, 0);
    if (R_FAILED(rc))
        fatalSimple(MAKERESULT(MODULE_HBL, 10));

    rc = smUnregisterService("haxx:hax");

    rc = smRegisterService(&g_port, "haxx:hax", false, 1);
    if (R_FAILED(rc))
        fatalSimple(MAKERESULT(MODULE_HBL, 12));

    rc = threadStart(&t);
    if (R_FAILED(rc))
        fatalSimple(MAKERESULT(MODULE_HBL, 13));

    Service srv;
    rc = smGetService(&srv, "haxx:hax");
    if (R_FAILED(rc))
        fatalSimple(MAKERESULT(MODULE_HBL, 23));

    IpcCommand ipc;
    ipcInitialize(&ipc);
    ipcSendPid(&ipc);

    struct {
        int x, y;
    }* raw;

    raw = ipcPrepareHeader(&ipc, sizeof(*raw));
    raw->x = raw->y = 0;
    
    u32 *tls = (u32 *)armGetTls();
    if (fake_pid) {
        tls[3] = fake_pid;
        tls[4] = 0xFFFE0000;
    }

    rc = serviceIpcDispatch(&srv);
    
    threadWaitForExit(&t);
    threadClose(&t);

    serviceClose(&srv);
    svcCloseHandle(g_port);
}


int main(int argc, char **argv)
{
    gfxInitDefault();
    consoleInit(NULL);

    getOwnProcessID(0);
    printf("Testing Real PID send:\n");
    printf("PID: %016lx\n", g_procID);
    printf("---\n");
    printf("Testing sending fake pid:\n");
    getOwnProcessID(0xCAFEBABE);
    printf("PID: %016lx\n", g_procID);
    // Main loop
    while(appletMainLoop())
    {
        //Scan all the inputs. This should be done once for each frame
        hidScanInput();

        //hidKeysDown returns information about which buttons have been just pressed (and they weren't in the previous frame)
        u64 kDown = hidKeysDown(CONTROLLER_P1_AUTO);

        if (kDown & KEY_PLUS) break; // break in order to return to hbmenu

        gfxFlushBuffers();
        gfxSwapBuffers();
        gfxWaitForVsync();
    }

    gfxExit();
    return 0;
}

You are on fire

oh

shoot

thats nice

nice work