/*
 * Copyright 2002-2019 Intel Corporation.
 * 
 * This software is provided to you as Sample Source Code as defined in the accompanying
 * End User License Agreement for the Intel(R) Software Development Products ("Agreement")
 * section 1.L.
 * 
 * This software and the related documents are provided as is, with no express or implied
 * warranties, other than those that are expressly stated in the License.
 */

/*
 *  This file contains an IA32 specific test for checking the return value of system calls.
 */

#include <iostream>
#include <fstream>
#include <stdlib.h>

#if defined(TARGET_MAC)
#include <sys/syscall.h>
#else
#include <syscall.h>
#endif

#include "pin.H"
using std::dec;
using std::ofstream;
using std::hex;
using std::endl;
using std::cout;


ofstream trace;

// Print syscall number and arguments
VOID SysBefore(ADDRINT ip, ADDRINT num, ADDRINT arg0, ADDRINT arg1, ADDRINT arg2,
               ADDRINT arg3, ADDRINT arg4, ADDRINT arg5)
{
#if defined(TARGET_IA32)
    // On ia32, there are only 5 registers for passing system call arguments,
    // but mmap needs 6. For mmap on ia32, the first argument to the system call
    // is a pointer to an array of the 6 arguments
    if (num == SYS_mmap)
    {
        ADDRINT * mmapArgs = &arg0;
        arg0 = mmapArgs[0];
        arg1 = mmapArgs[1];
        arg2 = mmapArgs[2];
        arg3 = mmapArgs[3];
        arg4 = mmapArgs[4];
        arg5 = mmapArgs[5];
    }
#endif

    trace << "@ip 0x" << hex << ip << ": sys call " << dec << num;
    trace << "(0x" << hex << arg0 << ", 0x" << arg1 << ", 0x" << arg2;
    trace << hex << ", 0x" << arg3 << ", 0x" << arg4 << ", 0x" << arg5 << ")" << endl;
}


// Print the return value of the system call
VOID SysAfter( ADDRINT value, INT32 err, UINT32 gax )
{
    int error = 0;
    ADDRINT neg_one = (ADDRINT)(0-1);

    if ( err == 0 )
    {
        if ( gax != value )
            error = 1;
    }
    else
    {
        if ( value != neg_one )
            error = 3;
        if ( err != -(INT32)gax )
            error = 4;
    }

    if ( error == 0 )
        trace << "Success: value=0x" << hex << value << ", errno=" << dec << err << endl;
    else
    {
        trace << "Failure " << error << ": value=0x" << hex << value << ", errno=" << dec << err;
        trace << ", gax=0x" << hex << gax << endl;
    }

    trace << endl;
}

VOID SyscallEntry(THREADID threadIndex, CONTEXT *ctxt, SYSCALL_STANDARD std, VOID *v)
{
    SysBefore(PIN_GetContextReg(ctxt, REG_INST_PTR),
        PIN_GetSyscallNumber(ctxt, std),
        PIN_GetSyscallArgument(ctxt, std, 0),
        PIN_GetSyscallArgument(ctxt, std, 1),
        PIN_GetSyscallArgument(ctxt, std, 2),
        PIN_GetSyscallArgument(ctxt, std, 3),
        PIN_GetSyscallArgument(ctxt, std, 4),
        PIN_GetSyscallArgument(ctxt, std, 5));
}

VOID SyscallExit(THREADID threadIndex, CONTEXT *ctxt, SYSCALL_STANDARD std, VOID *v)
{
    SysAfter(PIN_GetSyscallReturn(ctxt, std),
             PIN_GetSyscallErrno(ctxt, std),
             PIN_GetContextReg(ctxt, REG_GAX));
}


// Is called for every instruction and instruments syscalls
VOID Instruction(INS ins, VOID *v)
{
    // For O/S's (macOS*) that don't support PIN_AddSyscallEntryFunction(),
    // instrument the system call instruction.

    if (INS_IsSyscall(ins) && INS_IsValidForIpointAfter(ins))
    {
        // Arguments and syscall number is only available before
        INS_InsertCall(ins, IPOINT_BEFORE, AFUNPTR(SysBefore),
                       IARG_INST_PTR, IARG_SYSCALL_NUMBER,
                       IARG_SYSARG_VALUE, 0, IARG_SYSARG_VALUE, 1,
                       IARG_SYSARG_VALUE, 2, IARG_SYSARG_VALUE, 3,
                       IARG_SYSARG_VALUE, 4, IARG_SYSARG_VALUE, 5,
                       IARG_END);

        // return value only available after
        INS_InsertCall(ins, IPOINT_AFTER, AFUNPTR(SysAfter),
                       IARG_SYSRET_VALUE, IARG_SYSRET_ERRNO,
                       IARG_REG_VALUE, REG_GAX,
                       IARG_END);
    }
}


VOID Fini(INT32 code, VOID *v)
{
    trace << "#eof" << endl;
    trace.close();
}


int main(int argc, char *argv[])
{
    PIN_Init(argc, argv);

    trace.open( "strace.out" );
    if ( ! trace.is_open() )
    {
        cout << "Could not open strace.out" << endl;
        exit(1);
    }

    INS_AddInstrumentFunction(Instruction, 0);
    PIN_AddSyscallEntryFunction(SyscallEntry, 0);
    PIN_AddSyscallExitFunction(SyscallExit, 0);

    PIN_AddFiniFunction(Fini, 0);

    // Never returns
    PIN_StartProgram();

    return 0;
}