Question

我试图通过自制程序捕获由给定PID调用的所有系统调用（我不能使用任何strace，dtruss，gdb ......）。所以我使用了功能
kern_return_t task_set_emulation(task_t target_port, vm_address_t routine_entry_pt, int routine_number)中声明了/usr/include/mach/task.h 我写了一个小程序来捕捉系统调用write：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <mach/mach.h>
#include <mach/mach_vm.h>

void do_exit(char *msg)
{ 
  printf("Error::%s\n", msg);
  exit(42);
}

int main(void)
{ 
  mach_port_t the_task;
  mach_vm_address_t address;
  mach_vm_size_t size;
  mach_port_t the_thread;
  kern_return_t kerr;

  //Initialisation
  address = 0;
  size = 1ul * 1024;
  the_task = mach_task_self(); //Get the current program task
  kerr = mach_vm_allocate(the_task, &address, size, VM_MEMORY_MALLOC); //Allocate a new address for the test
  if (kerr != KERN_SUCCESS)
  { do_exit("vm_allocate"); }
  printf("address::%llx, size::%llu\n", address, size); //debug

  //Process
  kerr = task_set_emulation(the_task, address, SYS_write); //About to catch write syscalls
  the_thread = mach_thread_self(); //Verify if a thread is opened (even if it's obvious)
  printf("kerr::%d, thread::%d\n", kerr, the_thread); //debug
  if (kerr != KERN_SUCCESS)
  { do_exit("set_emulation"); }

  //Use some writes for the example
  write(1, "Bonjour\n", 8);
  write(1, "Bonjour\n", 8);
}

输出是：

address::0x106abe000, size::1024
kerr::46, thread::1295
Error::set_emulation

内核错误46对应于描述为＆＃34;空线程激活（没有链接到它的线程）的宏KERN_NOT_SUPPORTED＆＃34;在/usr/include/mach/kern_return.h中，甚至在我打电话给write之前就已经发生了我的问题是：在这个过程中我做错了什么？ Kern_not_supported是否意味着它尚未实现，而不是无意义的线程问题？

Answer 1

XNU中task_set_emulation的源代码是：

kern_return_t
task_set_emulation(                                                                                                                                                         
    __unused task_t     task,
    __unused vm_offset_t    routine_entry_pt,
    __unused int        routine_number)
{
    return KERN_NOT_SUPPORTED;
}

这意味着不支持task_set_emulation。

在Mac OS X上捕获系统调用

1 个答案: