syscall.cpp

#include <syscall.hpp>

#include <iostream>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <ostream>

#include <ctime>

using namespace dbt;

static inline int64_t cpucycles(void) {
  unsigned int hi, lo;
  unsigned int eax = 0;
  unsigned int ebx,ecx,edx;

   asm volatile
   ( "cpuid"
          : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
          : "0"(0)
  );

  __asm__ volatile("rdtsc\n\t" : "=a"(lo), "=d"(hi));
  return ((int64_t)lo) | (((int64_t)hi) << 32);
}

int LinuxSyscallManager::processSyscall(Machine& M) {
  SyscallType SysTy = static_cast<SyscallType>(M.getRegister(4) - 4000);

  switch (SysTy) {
  case SyscallType::Exit:
    ExitStatus = M.getRegister(2);
    if(!ROIMode)
      std::cerr << "Exiting with status " << (uint32_t) ExitStatus << " (" << M.getRegister(2) << ")\n";
    return 1;
  case SyscallType::Fstat: {
    //int r = fstat(M.getRegister(5), (struct stat*) (M.getByteMemoryPtr() + (M.getRegister(6) - M.getDataMemOffset())));
    //M.setRegister(2, r);
		M.setRegister(2, -1);
    return 0;
  }

  //GET/PUT right registers and memory locations
  case SyscallType::Read:{
    //fflush(stdin);
    ssize_t r = read(M.getRegister(5), (M.getByteMemoryPtr() + (M.getRegister(6) - M.getDataMemOffset())), M.getRegister(7));
    M.setRegister(2, r);
    return 0;
  }
  case SyscallType::Write: {
    size_t r;
    if(ROIMode)
      r = M.getRegister(7);
    else
      r = write(M.getRegister(5), (M.getByteMemoryPtr() + (M.getRegister(6) - M.getDataMemOffset())), M.getRegister(7));
    M.setRegister(2, r);
    return 0;
  }

  case SyscallType::Open: {
    const char* filename = M.getByteMemoryPtr() + (M.getRegister(5) - M.getDataMemOffset());
    const int flags = M.getRegister(6);

    ssize_t r = -1;
    if (flags == 0 || flags == 1 || flags == 2)
	r = open(filename, flags);
    else
	r = open(filename, flags | O_CREAT, S_IRWXU);

    M.setRegister(2, r);

    #ifdef DEBUG
    std::cerr << "Open file: " << filename << "; Flags:" << flags << " (r=" << r << ")" << std::endl;
    assert(r >= 0 && "Error with file descriptor..");
    #endif

    return 0;
  }

  case SyscallType::Close: {
    auto FD = M.getRegister(5);
    if (FD > 2) {
      ssize_t r = close(FD);
      M.setRegister(2, r);
    } else {
      M.setRegister(2, 0);
    }
    return 0;
  }

  case SyscallType::Creat: {
    const char* filename = M.getByteMemoryPtr() + (M.getRegister(5) - M.getDataMemOffset());
    const int flags = M.getRegister(6);

    ssize_t r = creat(filename, flags);
    M.setRegister(2, r);

    assert(r >= 0 && "Error with file descriptor..");
    return 0;
  }

  //Hack for rtdsc instruction
  case SyscallType::Stat: {
    static int64_t cpuc = 0;
    static uint32_t times = 0;

    std::cout << "[" << times++ << "]: " << (cpucycles()-cpuc) << std::endl;
    cpuc = cpucycles();
    return 0;
  }

  case SyscallType::Lseek: {
    //const char* filename = M.getByteMemoryPtr() + (M.getRegister(5) - M.getDataMemOffset());
    //const int flags = M.getRegister(6);

    ssize_t r = lseek(M.getRegister(5), M.getRegister(6), M.getRegister(7));
    M.setRegister(2, r);

    assert(r >= 0 && "Error with file descriptor..");
    return 0;
  }

  default:
    std::cerr << "Syscall (" << SysTy << ") not implemented!\n";
    exit(2);
    break;
  }
  return 0;
}