server/mach.c

   1 /*
   2  * Server-side debugger support using Mach primitives
   3  *
   4  * Copyright (C) 1999, 2006 Alexandre Julliard
   5  * Copyright (C) 2006 Ken Thomases for CodeWeavers
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  */
  21
  22 #include "config.h"
  23
  24 #include <assert.h>
  25 #include <errno.h>
  26 #include <stdio.h>
  27 #include <signal.h>
  28 #include <stdarg.h>
  29 #include <sys/types.h>
  30 #include <unistd.h>
  31 #ifdef HAVE_SYS_SYSCALL_H
  32 #include <sys/syscall.h>
  33 #endif
  34
  35 #include "ntstatus.h"
  36 #define WIN32_NO_STATUS
  37 #include "winternl.h"
  38
  39 #include "file.h"
  40 #include "process.h"
  41 #include "thread.h"
  42 #include "request.h"
  43
  44 #ifdef USE_MACH
  45
  46 #include <mach/mach.h>
  47 #include <mach/mach_error.h>
  48 #include <mach/thread_act.h>
  49 #include <mach/mach_vm.h>
  50 #include <servers/bootstrap.h>
  51
  52 static mach_port_t server_mach_port;
  53
  54 void sigchld_callback(void)
  55 {
  56     assert(0);  /* should never be called on MacOS */
  57 }
  58
  59 static void mach_set_error(kern_return_t mach_error)
  60 {
  61     switch (mach_error)
  62     {
  63         case KERN_SUCCESS:              break;
  64         case KERN_INVALID_ARGUMENT:     set_error(STATUS_INVALID_PARAMETER); break;
  65         case KERN_NO_SPACE:             set_error(STATUS_NO_MEMORY); break;
  66         case KERN_PROTECTION_FAILURE:   set_error(STATUS_ACCESS_DENIED); break;
  67         case KERN_INVALID_ADDRESS:      set_error(STATUS_ACCESS_VIOLATION); break;
  68         default:                        set_error(STATUS_UNSUCCESSFUL); break;
  69     }
  70 }
  71
  72 static mach_port_t get_process_port( struct process *process )
  73 {
  74     return process->trace_data;
  75 }
  76
  77 /* initialize the process control mechanism */
  78 void init_tracing_mechanism(void)
  79 {
  80     mach_port_t bp;
  81
  82     if (task_get_bootstrap_port(mach_task_self(), &bp) != KERN_SUCCESS)
  83         fatal_error("Can't find bootstrap port\n");
  84     if (mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_RECEIVE, &server_mach_port) != KERN_SUCCESS)
  85         fatal_error("Can't allocate port\n");
  86     if  (mach_port_insert_right( mach_task_self(),
  87                                  server_mach_port,
  88                                  server_mach_port,
  89                                  MACH_MSG_TYPE_MAKE_SEND ) != KERN_SUCCESS)
  90             fatal_error("Error inserting rights\n");
  91     if (bootstrap_register(bp, server_dir, server_mach_port) != KERN_SUCCESS)
  92         fatal_error("Can't check in server_mach_port\n");
  93     mach_port_deallocate(mach_task_self(), bp);
  94 }
  95
  96 /* initialize the per-process tracing mechanism */
  97 void init_process_tracing( struct process *process )
  98 {
  99     int pid, ret;
 100     struct
 101     {
 102         mach_msg_header_t           header;
 103         mach_msg_body_t             body;
 104         mach_msg_port_descriptor_t  task_port;
 105         mach_msg_trailer_t          trailer; /* only present on receive */
 106     } msg;
 107
 108     for (;;)
 109     {
 110         ret = mach_msg( &msg.header, MACH_RCV_MSG|MACH_RCV_TIMEOUT, 0, sizeof(msg),
 111                         server_mach_port, 0, 0 );
 112         if (ret)
 113         {
 114             if (ret != MACH_RCV_TIMED_OUT && debug_level)
 115                 fprintf( stderr, "warning: mach port receive failed with %x\n", ret );
 116             return;
 117         }
 118
 119         /* if anything in the message is invalid, ignore it */
 120         if (msg.header.msgh_size != offsetof(typeof(msg), trailer)) continue;
 121         if (msg.body.msgh_descriptor_count != 1) continue;
 122         if (msg.task_port.type != MACH_MSG_PORT_DESCRIPTOR) continue;
 123         if (msg.task_port.disposition != MACH_MSG_TYPE_PORT_SEND) continue;
 124         if (msg.task_port.name == MACH_PORT_NULL) continue;
 125         if (msg.task_port.name == MACH_PORT_DEAD) continue;
 126
 127         if (!pid_for_task( msg.task_port.name, &pid ))
 128         {
 129             struct thread *thread = get_thread_from_pid( pid );
 130
 131             if (thread && !thread->process->trace_data)
 132                 thread->process->trace_data = msg.task_port.name;
 133             else
 134                 mach_port_deallocate( mach_task_self(), msg.task_port.name );
 135         }
 136     }
 137 }
 138
 139 /* terminate the per-process tracing mechanism */
 140 void finish_process_tracing( struct process *process )
 141 {
 142     if (process->trace_data)
 143     {
 144         mach_port_deallocate( mach_task_self(), process->trace_data );
 145         process->trace_data = 0;
 146     }
 147 }
 148
 149 /* initialize registers in new thread if necessary */
 150 void init_thread_context( struct thread *thread )
 151 {
 152 }
 153
 154 /* retrieve the thread x86 registers */
 155 void get_thread_context( struct thread *thread, context_t *context, unsigned int flags )
 156 {
 157 #if defined(__i386__) || defined(__x86_64__)
 158     x86_debug_state_t state;
 159     mach_msg_type_number_t count = sizeof(state) / sizeof(int);
 160     mach_msg_type_name_t type;
 161     mach_port_t port, process_port = get_process_port( thread->process );
 162
 163     /* all other regs are handled on the client side */
 164     assert( flags == SERVER_CTX_DEBUG_REGISTERS );
 165
 166     if (thread->unix_pid == -1 || !process_port ||
 167         mach_port_extract_right( process_port, thread->unix_tid,
 168                                  MACH_MSG_TYPE_COPY_SEND, &port, &type ))
 169     {
 170         set_error( STATUS_ACCESS_DENIED );
 171         return;
 172     }
 173
 174     if (!thread_get_state( port, x86_DEBUG_STATE, (thread_state_t)&state, &count ))
 175     {
 176 #ifdef __x86_64__
 177         assert( state.dsh.flavor == x86_DEBUG_STATE32 ||
 178                 state.dsh.flavor == x86_DEBUG_STATE64 );
 179 #else
 180         assert( state.dsh.flavor == x86_DEBUG_STATE32 );
 181 #endif
 182
 183 #ifdef __x86_64__
 184         if (state.dsh.flavor == x86_DEBUG_STATE64)
 185         {
 186             context->debug.x86_64_regs.dr0 = state.uds.ds64.__dr0;
 187             context->debug.x86_64_regs.dr1 = state.uds.ds64.__dr1;
 188             context->debug.x86_64_regs.dr2 = state.uds.ds64.__dr2;
 189             context->debug.x86_64_regs.dr3 = state.uds.ds64.__dr3;
 190             context->debug.x86_64_regs.dr6 = state.uds.ds64.__dr6;
 191             context->debug.x86_64_regs.dr7 = state.uds.ds64.__dr7;
 192         }
 193         else
 194 #endif
 195         {
 196             context->debug.i386_regs.dr0 = state.uds.ds32.__dr0;
 197             context->debug.i386_regs.dr1 = state.uds.ds32.__dr1;
 198             context->debug.i386_regs.dr2 = state.uds.ds32.__dr2;
 199             context->debug.i386_regs.dr3 = state.uds.ds32.__dr3;
 200             context->debug.i386_regs.dr6 = state.uds.ds32.__dr6;
 201             context->debug.i386_regs.dr7 = state.uds.ds32.__dr7;
 202         }
 203         context->flags |= SERVER_CTX_DEBUG_REGISTERS;
 204     }
 205     mach_port_deallocate( mach_task_self(), port );
 206 #endif
 207 }
 208
 209 /* set the thread x86 registers */
 210 void set_thread_context( struct thread *thread, const context_t *context, unsigned int flags )
 211 {
 212 #if defined(__i386__) || defined(__x86_64__)
 213     x86_debug_state_t state;
 214     mach_msg_type_number_t count = sizeof(state) / sizeof(int);
 215     mach_msg_type_name_t type;
 216     mach_port_t port, process_port = get_process_port( thread->process );
 217     unsigned int dr7;
 218
 219     /* all other regs are handled on the client side */
 220     assert( flags == SERVER_CTX_DEBUG_REGISTERS );
 221
 222     if (thread->unix_pid == -1 || !process_port ||
 223         mach_port_extract_right( process_port, thread->unix_tid,
 224                                  MACH_MSG_TYPE_COPY_SEND, &port, &type ))
 225     {
 226         set_error( STATUS_ACCESS_DENIED );
 227         return;
 228     }
 229
 230
 231 #ifdef __x86_64__
 232     if (thread->process->machine == IMAGE_FILE_MACHINE_AMD64)
 233     {
 234         /* Mac OS doesn't allow setting the global breakpoint flags */
 235         dr7 = (context->debug.x86_64_regs.dr7 & ~0xaa) | ((context->debug.x86_64_regs.dr7 & 0xaa) >> 1);
 236
 237         state.dsh.flavor = x86_DEBUG_STATE64;
 238         state.dsh.count = sizeof(state.uds.ds64) / sizeof(int);
 239         state.uds.ds64.__dr0 = context->debug.x86_64_regs.dr0;
 240         state.uds.ds64.__dr1 = context->debug.x86_64_regs.dr1;
 241         state.uds.ds64.__dr2 = context->debug.x86_64_regs.dr2;
 242         state.uds.ds64.__dr3 = context->debug.x86_64_regs.dr3;
 243         state.uds.ds64.__dr4 = 0;
 244         state.uds.ds64.__dr5 = 0;
 245         state.uds.ds64.__dr6 = context->debug.x86_64_regs.dr6;
 246         state.uds.ds64.__dr7 = dr7;
 247     }
 248     else
 249 #endif
 250     {
 251         dr7 = (context->debug.i386_regs.dr7 & ~0xaa) | ((context->debug.i386_regs.dr7 & 0xaa) >> 1);
 252
 253         state.dsh.flavor = x86_DEBUG_STATE32;
 254         state.dsh.count = sizeof(state.uds.ds32) / sizeof(int);
 255         state.uds.ds32.__dr0 = context->debug.i386_regs.dr0;
 256         state.uds.ds32.__dr1 = context->debug.i386_regs.dr1;
 257         state.uds.ds32.__dr2 = context->debug.i386_regs.dr2;
 258         state.uds.ds32.__dr3 = context->debug.i386_regs.dr3;
 259         state.uds.ds32.__dr4 = 0;
 260         state.uds.ds32.__dr5 = 0;
 261         state.uds.ds32.__dr6 = context->debug.i386_regs.dr6;
 262         state.uds.ds32.__dr7 = dr7;
 263     }
 264     thread_set_state( port, x86_DEBUG_STATE, (thread_state_t)&state, count );
 265     mach_port_deallocate( mach_task_self(), port );
 266 #endif
 267 }
 268
 269 int send_thread_signal( struct thread *thread, int sig )
 270 {
 271     int ret = -1;
 272     mach_port_t process_port = get_process_port( thread->process );
 273
 274     if (thread->unix_pid != -1 && process_port)
 275     {
 276         mach_msg_type_name_t type;
 277         mach_port_t port;
 278
 279         if (!mach_port_extract_right( process_port, thread->unix_tid,
 280                                       MACH_MSG_TYPE_COPY_SEND, &port, &type ))
 281         {
 282             ret = syscall( SYS___pthread_kill, port, sig );
 283             mach_port_deallocate( mach_task_self(), port );
 284         }
 285         else errno = ESRCH;
 286
 287         if (ret == -1 && errno == ESRCH) /* thread got killed */
 288         {
 289             thread->unix_pid = -1;
 290             thread->unix_tid = -1;
 291         }
 292     }
 293     if (debug_level && ret != -1)
 294         fprintf( stderr, "%04x: *sent signal* signal=%d\n", thread->id, sig );
 295     return (ret != -1);
 296 }
 297
 298 /* read data from a process memory space */
 299 int read_process_memory( struct process *process, client_ptr_t ptr, data_size_t size, char *dest )
 300 {
 301     kern_return_t ret;
 302     mach_msg_type_number_t bytes_read;
 303     mach_vm_offset_t offset;
 304     vm_offset_t data;
 305     mach_vm_address_t aligned_address;
 306     mach_vm_size_t aligned_size;
 307     unsigned int page_size = get_page_size();
 308     mach_port_t process_port = get_process_port( process );
 309
 310     if (!process_port)
 311     {
 312         set_error( STATUS_ACCESS_DENIED );
 313         return 0;
 314     }
 315     if ((mach_vm_address_t)ptr != ptr)
 316     {
 317         set_error( STATUS_ACCESS_DENIED );
 318         return 0;
 319     }
 320
 321     if ((ret = task_suspend( process_port )) != KERN_SUCCESS)
 322     {
 323         mach_set_error( ret );
 324         return 0;
 325     }
 326
 327     offset = ptr % page_size;
 328     aligned_address = (mach_vm_address_t)(ptr - offset);
 329     aligned_size = (size + offset + page_size - 1) / page_size * page_size;
 330
 331     ret = mach_vm_read( process_port, aligned_address, aligned_size, &data, &bytes_read );
 332     if (ret != KERN_SUCCESS) mach_set_error( ret );
 333     else
 334     {
 335         memcpy( dest, (char *)data + offset, size );
 336         mach_vm_deallocate( mach_task_self(), data, bytes_read );
 337     }
 338     task_resume( process_port );
 339     return (ret == KERN_SUCCESS);
 340 }
 341
 342 /* write data to a process memory space */
 343 int write_process_memory( struct process *process, client_ptr_t ptr, data_size_t size, const char *src )
 344 {
 345     kern_return_t ret;
 346     mach_vm_address_t aligned_address, region_address;
 347     mach_vm_size_t aligned_size, region_size;
 348     mach_msg_type_number_t info_size, bytes_read;
 349     mach_vm_offset_t offset;
 350     vm_offset_t task_mem = 0;
 351     struct vm_region_basic_info_64 info;
 352     mach_port_t dummy;
 353     unsigned int page_size = get_page_size();
 354     mach_port_t process_port = get_process_port( process );
 355
 356     if (!process_port)
 357     {
 358         set_error( STATUS_ACCESS_DENIED );
 359         return 0;
 360     }
 361     if ((mach_vm_address_t)ptr != ptr)
 362     {
 363         set_error( STATUS_ACCESS_DENIED );
 364         return 0;
 365     }
 366
 367     offset = ptr % page_size;
 368     aligned_address = (mach_vm_address_t)(ptr - offset);
 369     aligned_size = (size + offset + page_size - 1) / page_size * page_size;
 370
 371     if ((ret = task_suspend( process_port )) != KERN_SUCCESS)
 372     {
 373         mach_set_error( ret );
 374         return 0;
 375     }
 376
 377     ret = mach_vm_read( process_port, aligned_address, aligned_size, &task_mem, &bytes_read );
 378     if (ret != KERN_SUCCESS)
 379     {
 380         mach_set_error( ret );
 381         goto failed;
 382     }
 383     region_address = aligned_address;
 384     info_size = sizeof(info);
 385     ret = mach_vm_region( process_port, &region_address, &region_size, VM_REGION_BASIC_INFO_64,
 386                      (vm_region_info_t)&info, &info_size, &dummy );
 387     if (ret != KERN_SUCCESS)
 388     {
 389         mach_set_error( ret );
 390         goto failed;
 391     }
 392     if (region_address > aligned_address ||
 393         region_address + region_size < aligned_address + aligned_size)
 394     {
 395         /* FIXME: should support multiple regions */
 396         set_error( ERROR_ACCESS_DENIED );
 397         goto failed;
 398     }
 399     ret = mach_vm_protect( process_port, aligned_address, aligned_size, 0, VM_PROT_READ | VM_PROT_WRITE );
 400     if (ret != KERN_SUCCESS)
 401     {
 402         mach_set_error( ret );
 403         goto failed;
 404     }
 405
 406     /* FIXME: there's an optimization that can be made: check first and last */
 407     /* pages for writability; read first and last pages; write interior */
 408     /* pages to task without ever reading&modifying them; if that succeeds, */
 409     /* modify first and last pages and write them. */
 410
 411     memcpy( (char*)task_mem + offset, src, size );
 412
 413     ret = mach_vm_write( process_port, aligned_address, task_mem, bytes_read );
 414     if (ret != KERN_SUCCESS) mach_set_error( ret );
 415     else
 416     {
 417         mach_vm_deallocate( mach_task_self(), task_mem, bytes_read );
 418         /* restore protection */
 419         mach_vm_protect( process_port, aligned_address, aligned_size, 0, info.protection );
 420         task_resume( process_port );
 421         return 1;
 422     }
 423
 424 failed:
 425     if (task_mem) mach_vm_deallocate( mach_task_self(), task_mem, bytes_read );
 426     task_resume( process_port );
 427     return 0;
 428 }
 429
 430 /* retrieve an LDT selector entry */
 431 void get_selector_entry( struct thread *thread, int entry, unsigned int *base,
 432                          unsigned int *limit, unsigned char *flags )
 433 {
 434     const unsigned int total_size = (2 * sizeof(int) + 1) * 8192;
 435     struct process *process = thread->process;
 436     unsigned int page_size = get_page_size();
 437     vm_offset_t data;
 438     kern_return_t ret;
 439     mach_msg_type_number_t bytes_read;
 440     mach_port_t process_port = get_process_port( thread->process );
 441
 442     if (!process->ldt_copy || !process_port)
 443     {
 444         set_error( STATUS_ACCESS_DENIED );
 445         return;
 446     }
 447     if (entry >= 8192)
 448     {
 449         set_error( STATUS_INVALID_PARAMETER );  /* FIXME */
 450         return;
 451     }
 452
 453     if ((ret = task_suspend( process_port )) == KERN_SUCCESS)
 454     {
 455         mach_vm_offset_t offset = process->ldt_copy % page_size;
 456         mach_vm_address_t aligned_address = (mach_vm_address_t)(process->ldt_copy - offset);
 457         mach_vm_size_t aligned_size = (total_size + offset + page_size - 1) / page_size * page_size;
 458
 459         ret = mach_vm_read( process_port, aligned_address, aligned_size, &data, &bytes_read );
 460         if (ret != KERN_SUCCESS) mach_set_error( ret );
 461         else
 462         {
 463             const int *ldt = (const int *)((char *)data + offset);
 464             memcpy( base, ldt + entry, sizeof(int) );
 465             memcpy( limit, ldt + entry + 8192, sizeof(int) );
 466             memcpy( flags, (char *)(ldt + 2 * 8192) + entry, 1 );
 467             mach_vm_deallocate( mach_task_self(), data, bytes_read );
 468         }
 469         task_resume( process_port );
 470     }
 471     else mach_set_error( ret );
 472 }
 473
 474 #endif  /* USE_MACH */