X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/2d21ac55c334faf3a56e5634905ed6987fc787d4..bb59bff194111743b33cc36712410b5656329d3c:/osfmk/kern/exception.c?ds=inline diff --git a/osfmk/kern/exception.c b/osfmk/kern/exception.c index 0122c44b1..7d9cb9342 100644 --- a/osfmk/kern/exception.c +++ b/osfmk/kern/exception.c @@ -56,8 +56,6 @@ /* */ -#include - #include #include #include @@ -86,22 +84,7 @@ #include #include #include - -#if MACH_KDB -#include -#endif /* MACH_KDB */ - -#if MACH_KDB - -#include - -#if iPSC386 || iPSC860 -boolean_t debug_user_with_kdb = TRUE; -#else -boolean_t debug_user_with_kdb = FALSE; -#endif - -#endif /* MACH_KDB */ +#include unsigned long c_thr_exc_raise = 0; unsigned long c_thr_exc_raise_state = 0; @@ -117,7 +100,13 @@ kern_return_t exception_deliver( mach_exception_data_t code, mach_msg_type_number_t codeCnt, struct exception_action *excp, - mutex_t *mutex); + lck_mtx_t *mutex); + +static kern_return_t +check_exc_receiver_dependancy( + exception_type_t exception, + struct exception_action *excp, + lck_mtx_t *mutex); #ifdef MACH_BSD kern_return_t bsd_exception( @@ -145,7 +134,7 @@ exception_deliver( mach_exception_data_t code, mach_msg_type_number_t codeCnt, struct exception_action *excp, - mutex_t *mutex) + lck_mtx_t *mutex) { ipc_port_t exc_port; exception_data_type_t small_code[EXCEPTION_CODE_MAX]; @@ -161,6 +150,19 @@ exception_deliver( if (!thread->active) return KERN_SUCCESS; + /* + * If there are no exception actions defined for this entity, + * we can't deliver here. + */ + if (excp == NULL) + return KERN_FAILURE; + + assert(exception < EXC_TYPES_COUNT); + if (exception >= EXC_TYPES_COUNT) + return KERN_FAILURE; + + excp = &excp[exception]; + /* * Snapshot the exception action data under lock for consistency. * Hold a reference to the port over the exception_raise_* calls @@ -168,16 +170,16 @@ exception_deliver( * the port from disappearing between now and when * ipc_object_copyin_from_kernel is finally called. */ - mutex_lock(mutex); + lck_mtx_lock(mutex); exc_port = excp->port; if (!IP_VALID(exc_port)) { - mutex_unlock(mutex); + lck_mtx_unlock(mutex); return KERN_FAILURE; } ip_lock(exc_port); if (!ip_active(exc_port)) { ip_unlock(exc_port); - mutex_unlock(mutex); + lck_mtx_unlock(mutex); return KERN_FAILURE; } ip_reference(exc_port); @@ -186,14 +188,14 @@ exception_deliver( flavor = excp->flavor; behavior = excp->behavior; - mutex_unlock(mutex); + lck_mtx_unlock(mutex); code64 = (behavior & MACH_EXCEPTION_CODES); behavior &= ~MACH_EXCEPTION_CODES; if (!code64) { - small_code[0] = CAST_DOWN(exception_data_type_t, code[0]); - small_code[1] = CAST_DOWN(exception_data_type_t, code[1]); + small_code[0] = CAST_DOWN_EXPLICIT(exception_data_type_t, code[0]); + small_code[1] = CAST_DOWN_EXPLICIT(exception_data_type_t, code[1]); } @@ -300,6 +302,42 @@ exception_deliver( }/* switch */ } +/* + * Routine: check_exc_receiver_dependancy + * Purpose: + * Verify that the port destined for receiving this exception is not + * on the current task. This would cause hang in kernel for + * EXC_CRASH primarily. Note: If port is transferred + * between check and delivery then deadlock may happen. + * + * Conditions: + * Nothing locked and no resources held. + * Called from an exception context. + * Returns: + * KERN_SUCCESS if its ok to send exception message. + */ +kern_return_t +check_exc_receiver_dependancy( + exception_type_t exception, + struct exception_action *excp, + lck_mtx_t *mutex) +{ + kern_return_t retval = KERN_SUCCESS; + + if (excp == NULL || exception != EXC_CRASH) + return retval; + + task_t task = current_task(); + lck_mtx_lock(mutex); + ipc_port_t xport = excp[exception].port; + if ( IP_VALID(xport) + && ip_active(xport) + && task->itk_space == xport->ip_receiver) + retval = KERN_FAILURE; + lck_mtx_unlock(mutex); + return retval; +} + /* * Routine: exception * Purpose: @@ -322,65 +360,58 @@ exception_triage( thread_t thread; task_t task; host_priv_t host_priv; - struct exception_action *excp; - mutex_t *mutex; - kern_return_t kr; + lck_mtx_t *mutex; + kern_return_t kr; assert(exception != EXC_RPC_ALERT); - if (exception == KERN_SUCCESS) - panic("exception"); + thread = current_thread(); /* * Try to raise the exception at the activation level. */ - thread = current_thread(); - mutex = mutex_addr(thread->mutex); - excp = &thread->exc_actions[exception]; - kr = exception_deliver(thread, exception, code, codeCnt, excp, mutex); - if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED) - goto out; + mutex = &thread->mutex; + if (KERN_SUCCESS == check_exc_receiver_dependancy(exception, thread->exc_actions, mutex)) + { + kr = exception_deliver(thread, exception, code, codeCnt, thread->exc_actions, mutex); + if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED) + goto out; + } /* * Maybe the task level will handle it. */ task = current_task(); - mutex = mutex_addr(task->lock); - excp = &task->exc_actions[exception]; - kr = exception_deliver(thread, exception, code, codeCnt, excp, mutex); - if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED) - goto out; + mutex = &task->lock; + if (KERN_SUCCESS == check_exc_receiver_dependancy(exception, task->exc_actions, mutex)) + { + kr = exception_deliver(thread, exception, code, codeCnt, task->exc_actions, mutex); + if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED) + goto out; + } /* * How about at the host level? */ host_priv = host_priv_self(); - mutex = mutex_addr(host_priv->lock); - excp = &host_priv->exc_actions[exception]; - kr = exception_deliver(thread, exception, code, codeCnt, excp, mutex); - if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED) - goto out; + mutex = &host_priv->lock; + + if (KERN_SUCCESS == check_exc_receiver_dependancy(exception, host_priv->exc_actions, mutex)) + { + kr = exception_deliver(thread, exception, code, codeCnt, host_priv->exc_actions, mutex); + if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED) + goto out; + } /* * Nobody handled it, terminate the task. */ -#if MACH_KDB - if (debug_user_with_kdb) { - /* - * Debug the exception with kdb. - * If kdb handles the exception, - * then thread_kdb_return won't return. - */ - db_printf("No exception server, calling kdb...\n"); - thread_kdb_return(); - } -#endif /* MACH_KDB */ - (void) task_terminate(task); out: - if (exception != EXC_CRASH) + if ((exception != EXC_CRASH) && (exception != EXC_RESOURCE) && + (exception != EXC_GUARD)) thread_exception_return(); return; } @@ -392,8 +423,7 @@ bsd_exception( mach_msg_type_number_t codeCnt) { task_t task; - struct exception_action *excp; - mutex_t *mutex; + lck_mtx_t *mutex; thread_t self = current_thread(); kern_return_t kr; @@ -401,10 +431,9 @@ bsd_exception( * Maybe the task level will handle it. */ task = current_task(); - mutex = mutex_addr(task->lock); - excp = &task->exc_actions[exception]; + mutex = &task->lock; - kr = exception_deliver(self, exception, code, codeCnt, excp, mutex); + kr = exception_deliver(self, exception, code, codeCnt, task->exc_actions, mutex); if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED) return(KERN_SUCCESS); @@ -413,11 +442,11 @@ bsd_exception( /* - * Raise an EXC_CRASH exception on the dying task. + * Raise an exception on a task. * This should tell launchd to launch Crash Reporter for this task. */ -kern_return_t abnormal_exit_notify(mach_exception_data_type_t exccode, - mach_exception_data_type_t excsubcode) +kern_return_t task_exception_notify(exception_type_t exception, + mach_exception_data_type_t exccode, mach_exception_data_type_t excsubcode) { mach_exception_data_type_t code[EXCEPTION_CODE_MAX]; wait_interrupt_t wsave; @@ -426,7 +455,7 @@ kern_return_t abnormal_exit_notify(mach_exception_data_type_t exccode, code[1] = excsubcode; wsave = thread_interrupt_level(THREAD_UNINT); - exception_triage(EXC_CRASH, code, EXCEPTION_CODE_MAX); + exception_triage(exception, code, EXCEPTION_CODE_MAX); (void) thread_interrupt_level(wsave); return (KERN_SUCCESS); } @@ -439,7 +468,6 @@ kern_return_t abnormal_exit_notify(mach_exception_data_type_t exccode, kern_return_t sys_perf_notify(thread_t thread, int pid) { host_priv_t hostp; - struct exception_action *excp; ipc_port_t xport; wait_interrupt_t wsave; kern_return_t ret; @@ -450,8 +478,7 @@ kern_return_t sys_perf_notify(thread_t thread, int pid) code[1] = pid; /* Pass out the pid */ struct task *task = thread->task; - excp = &hostp->exc_actions[EXC_RPC_ALERT]; - xport = excp->port; + xport = hostp->exc_actions[EXC_RPC_ALERT].port; /* Make sure we're not catching our own exception */ if (!IP_VALID(xport) || @@ -467,7 +494,7 @@ kern_return_t sys_perf_notify(thread_t thread, int pid) EXC_RPC_ALERT, code, 2, - excp, + hostp->exc_actions, &hostp->lock); (void)thread_interrupt_level(wsave);