Commit 63f62097 authored by Ramon Nou's avatar Ramon Nou
Browse files

Add getpid option

parent 90bcb734

src/eval.cpp

+10 −1
Original line number Diff line number Diff line
@@ -10,6 +10,10 @@ int hook_openat(int dirfd, const char *cpath, int flags, mode_t mode) { 
  return syscall_no_intercept(SYS_openat, dirfd, cpath, flags, mode);

}



int hook_getpid() {

  return 42;

}



inline int hook(long syscall_number, long arg0, long arg1, long arg2, long arg3,

                long arg4, long arg5, long *result) {
@@ -26,6 +30,9 @@ inline int hook(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
                          reinterpret_cast<const char *>(arg1),

                          static_cast<int>(arg2), static_cast<mode_t>(arg3));

    break;

  case SYS_getpid:

    *result = hook_getpid();

    break;

  default:

    // ignore any other syscalls, i.e.: pass them on to the kernel

    // (syscalls forwarded to the kernel that return are logged in
@@ -46,7 +53,9 @@ int hook_guard_wrapper(long syscall_number, long arg0, long arg1, long arg2, 
  if (syscall_number == SYS_openat)

    was_hooked = hook(syscall_number, arg0, arg1, arg2, arg3, arg4, arg5,

                      syscall_return_value);



  else

  if (syscall_number == SYS_getpid)

    was_hooked = hook(syscall_number);

  return was_hooked;

}

src/opendevnull.cpp

+54 −26
Original line number Diff line number Diff line
@@ -4,11 +4,27 @@ 
#include <sys/syscall.h>

#include <unistd.h>



int main() {

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

    // Check if the correct number of arguments is provided

    if (argc != 3) {

        std::cerr << "Usage: " << argv[0] << " --syscall <open|getpid>" << std::endl;

        return 1;

    }







  // measure time to run in microseconds

  

  std::string option = argv[1];

  std::string syscall = argv[2];



  double reps = 1000.0*100000.0;

   // Handle the --syscall option

  if (option == "--syscall") {

    if (syscall == "open") {



      struct timespec start, end;

      clock_gettime(CLOCK_MONOTONIC, &start);

  // open /dev/null 100000 times

    

      for (int j = 0; j < 1000; j++) {

        for (int i = 0; i < 100000; i++) {
@@ -20,20 +36,32 @@ int main() { 
      clock_gettime(CLOCK_MONOTONIC, &end);

      double time_taken =

          (end.tv_sec - start.tv_sec) * 1e6 + (end.tv_nsec - start.tv_nsec) / 1e3;

  std::cout << "Time taken: " << time_taken << " microseconds" << std::endl;

  // mean of the time for a syscall (10000000)



  std::cout << "Mean time taken: " << time_taken / 100000000.0 << " microseconds"



      std::cout << "Mean time taken: " << time_taken / reps << " microseconds"

                << std::endl;

  // Calculate single syscall ()

    }

    else if (syscall == "getpid") {

      struct timespec start, end;

            clock_gettime(CLOCK_MONOTONIC, &start);

  int fd = openat(AT_FDCWD, "/dev/null", O_RDWR, 0);

  close(fd);

          

            for (int j = 0; j < 1000; j++) {

              for (int i = 0; i < 100000; i++) {

                int ret = getpid();

              }

            }

            clock_gettime(CLOCK_MONOTONIC, &end);

  std::cout << "Time taken for single syscall: "

            << (end.tv_sec - start.tv_sec) * 1e6 +

                   (end.tv_nsec - start.tv_nsec) / 1e3

            << " microseconds" << std::endl;

            double time_taken =

                (end.tv_sec - start.tv_sec) * 1e6 + (end.tv_nsec - start.tv_nsec) / 1e3;





            std::cout << "Mean time taken: " << time_taken / reps << " microseconds"

                      << std::endl;









    } 



  return 0;

}