1                 : /*
       2                 :  * Copyright (c) 2013 The Native Client Authors. All rights reserved.
       3                 :  * Use of this source code is governed by a BSD-style license that can be
       4                 :  * found in the LICENSE file.
       5                 :  */
       6                 : 
       7                 : #include "native_client/src/trusted/service_runtime/sys_exception.h"
       8                 : 
       9                 : #include "native_client/src/shared/platform/nacl_sync_checked.h"
      10                 : #include "native_client/src/trusted/service_runtime/include/sys/errno.h"
      11                 : #include "native_client/src/trusted/service_runtime/nacl_app_thread.h"
      12                 : #include "native_client/src/trusted/service_runtime/nacl_copy.h"
      13                 : #include "native_client/src/trusted/service_runtime/sel_ldr.h"
      14                 : #include "native_client/src/trusted/service_runtime/win/debug_exception_handler.h"
      15                 : 
      16                 : 
      17             166 : int32_t NaClSysExceptionHandler(struct NaClAppThread *natp,
      18                 :                                 uint32_t             handler_addr,
      19                 :                                 uint32_t             old_handler) {
      20             166 :   struct NaClApp *nap = natp->nap;
      21             166 :   int32_t rv = -NACL_ABI_EINVAL;
      22                 : 
      23             166 :   if (!nap->enable_exception_handling) {
      24               2 :     rv = -NACL_ABI_ENOSYS;
      25               2 :     goto no_lock_exit;
      26                 :   }
      27             164 :   if (!NaClIsValidJumpTarget(nap, handler_addr)) {
      28               2 :     rv = -NACL_ABI_EFAULT;
      29               2 :     goto no_lock_exit;
      30                 :   }
      31             162 :   NaClXMutexLock(&nap->exception_mu);
      32                 : 
      33                 :   /*
      34                 :    * This needs to be done while holding the lock so that we don't
      35                 :    * start two Windows debug exception handlers.
      36                 :    */
      37             162 :   if (handler_addr != 0) {
      38             104 :     if (!NaClDebugExceptionHandlerEnsureAttached(nap)) {
      39               0 :       rv = -NACL_ABI_ENOSYS;
      40               0 :       goto unlock_exit;
      41                 :     }
      42                 :   }
      43                 : 
      44             164 :   if (0 != old_handler &&
      45               2 :       !NaClCopyOutToUser(nap, (uintptr_t) old_handler,
      46               2 :                          &nap->exception_handler,
      47                 :                          sizeof nap->exception_handler)) {
      48               0 :     rv = -NACL_ABI_EFAULT;
      49               0 :     goto unlock_exit;
      50                 :   }
      51             162 :   nap->exception_handler = handler_addr;
      52             162 :   rv = 0;
      53                 :  unlock_exit:
      54             162 :   NaClXMutexUnlock(&nap->exception_mu);
      55                 :  no_lock_exit:
      56             166 :   return rv;
      57                 : }
      58                 : 
      59              41 : int32_t NaClSysExceptionStack(struct NaClAppThread *natp,
      60                 :                               uint32_t             stack_addr,
      61                 :                               uint32_t             stack_size) {
      62              41 :   if (!natp->nap->enable_exception_handling) {
      63               2 :     return -NACL_ABI_ENOSYS;
      64                 :   }
      65              39 :   if (kNaClBadAddress == NaClUserToSysAddrNullOkay(natp->nap,
      66                 :                                                    stack_addr + stack_size)) {
      67               0 :     return -NACL_ABI_EINVAL;
      68                 :   }
      69              39 :   natp->exception_stack = stack_addr + stack_size;
      70              39 :   return 0;
      71                 : }
      72                 : 
      73          115345 : int32_t NaClSysExceptionClearFlag(struct NaClAppThread *natp) {
      74          115345 :   if (!natp->nap->enable_exception_handling) {
      75               2 :     return -NACL_ABI_ENOSYS;
      76                 :   }
      77          115343 :   natp->exception_flag = 0;
      78          115343 :   return 0;
      79                 : }