X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/6601e61aa18bf4f09af135ff61fc7f4771d23b06..d26ffc64f583ab2d29df48f13518685602bc8832:/osfmk/kern/ipc_tt.c diff --git a/osfmk/kern/ipc_tt.c b/osfmk/kern/ipc_tt.c index 24f41f754..920ac8fc5 100644 --- a/osfmk/kern/ipc_tt.c +++ b/osfmk/kern/ipc_tt.c @@ -1,23 +1,29 @@ /* - * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2010 Apple Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. * - * @APPLE_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ @@ -47,6 +53,12 @@ * any improvements or extensions that they make and grant Carnegie Mellon * the rights to redistribute these changes. */ +/* + * NOTICE: This file was modified by McAfee Research in 2004 to introduce + * support for mandatory and extensible security protections. This notice + * is included in support of clause 2.2 (b) of the Apple Public License, + * Version 2.0. + */ /* */ @@ -82,12 +94,20 @@ #include #include -#include #include +#include + +#if CONFIG_EMBEDDED && !SECURE_KERNEL +extern int cs_relax_platform_task_ports; +#endif + /* forward declarations */ task_t convert_port_to_locked_task(ipc_port_t port); - +task_inspect_t convert_port_to_locked_task_inspect(ipc_port_t port); +static void ipc_port_bind_special_reply_port_locked(ipc_port_t port); +static kern_return_t ipc_port_unbind_special_reply_port(thread_t thread, boolean_t unbind_active_port); +kern_return_t task_conversion_eval(task_t caller, task_t victim); /* * Routine: ipc_task_init @@ -107,6 +127,7 @@ ipc_task_init( { ipc_space_t space; ipc_port_t kport; + ipc_port_t nport; kern_return_t kr; int i; @@ -115,17 +136,38 @@ ipc_task_init( if (kr != KERN_SUCCESS) panic("ipc_task_init"); + space->is_task = task; kport = ipc_port_alloc_kernel(); if (kport == IP_NULL) panic("ipc_task_init"); + nport = ipc_port_alloc_kernel(); + if (nport == IP_NULL) + panic("ipc_task_init"); + itk_lock_init(task); task->itk_self = kport; - task->itk_sself = ipc_port_make_send(kport); + task->itk_nself = nport; + task->itk_resume = IP_NULL; /* Lazily allocated on-demand */ + if (task_is_a_corpse_fork(task)) { + /* + * No sender's notification for corpse would not + * work with a naked send right in kernel. + */ + task->itk_sself = IP_NULL; + } else { + task->itk_sself = ipc_port_make_send(kport); + } + task->itk_debug_control = IP_NULL; task->itk_space = space; - space->is_fast = FALSE; +#if CONFIG_MACF + for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) { + mac_exc_associate_action_label(&task->exc_actions[i], mac_exc_create_label()); + } +#endif + if (parent == TASK_NULL) { ipc_port_t port; @@ -138,6 +180,9 @@ ipc_task_init( task->itk_host = port; task->itk_bootstrap = IP_NULL; + task->itk_seatbelt = IP_NULL; + task->itk_gssd = IP_NULL; + task->itk_task_access = IP_NULL; for (i = 0; i < TASK_PORT_REGISTER_MAX; i++) task->itk_registered[i] = IP_NULL; @@ -162,6 +207,9 @@ ipc_task_init( parent->exc_actions[i].behavior; task->exc_actions[i].privileged = parent->exc_actions[i].privileged; +#if CONFIG_MACF + mac_exc_inherit_action_label(parent->exc_actions + i, task->exc_actions + i); +#endif }/* for */ task->itk_host = ipc_port_copy_send(parent->itk_host); @@ -169,6 +217,15 @@ ipc_task_init( task->itk_bootstrap = ipc_port_copy_send(parent->itk_bootstrap); + task->itk_seatbelt = + ipc_port_copy_send(parent->itk_seatbelt); + + task->itk_gssd = + ipc_port_copy_send(parent->itk_gssd); + + task->itk_task_access = + ipc_port_copy_send(parent->itk_task_access); + itk_unlock(parent); } } @@ -186,11 +243,15 @@ ipc_task_enable( task_t task) { ipc_port_t kport; + ipc_port_t nport; itk_lock(task); kport = task->itk_self; if (kport != IP_NULL) ipc_kobject_set(kport, (ipc_kobject_t) task, IKOT_TASK); + nport = task->itk_nself; + if (nport != IP_NULL) + ipc_kobject_set(nport, (ipc_kobject_t) task, IKOT_TASK_NAME); itk_unlock(task); } @@ -207,11 +268,33 @@ ipc_task_disable( task_t task) { ipc_port_t kport; + ipc_port_t nport; + ipc_port_t rport; itk_lock(task); kport = task->itk_self; if (kport != IP_NULL) ipc_kobject_set(kport, IKO_NULL, IKOT_NONE); + nport = task->itk_nself; + if (nport != IP_NULL) + ipc_kobject_set(nport, IKO_NULL, IKOT_NONE); + + rport = task->itk_resume; + if (rport != IP_NULL) { + /* + * From this point onwards this task is no longer accepting + * resumptions. + * + * There are still outstanding suspensions on this task, + * even as it is being torn down. Disconnect the task + * from the rport, thereby "orphaning" the rport. The rport + * itself will go away only when the last suspension holder + * destroys his SO right to it -- when he either + * exits, or tries to actually use that last SO right to + * resume this (now non-existent) task. + */ + ipc_kobject_set(rport, IKO_NULL, IKOT_NONE); + } itk_unlock(task); } @@ -229,6 +312,8 @@ ipc_task_terminate( task_t task) { ipc_port_t kport; + ipc_port_t nport; + ipc_port_t rport; int i; itk_lock(task); @@ -239,8 +324,15 @@ ipc_task_terminate( itk_unlock(task); return; } - task->itk_self = IP_NULL; + + nport = task->itk_nself; + assert(nport != IP_NULL); + task->itk_nself = IP_NULL; + + rport = task->itk_resume; + task->itk_resume = IP_NULL; + itk_unlock(task); /* release the naked send rights */ @@ -252,6 +344,9 @@ ipc_task_terminate( if (IP_VALID(task->exc_actions[i].port)) { ipc_port_release_send(task->exc_actions[i].port); } +#if CONFIG_MACF + mac_exc_free_action_label(task->exc_actions + i); +#endif } if (IP_VALID(task->itk_host)) @@ -260,22 +355,38 @@ ipc_task_terminate( if (IP_VALID(task->itk_bootstrap)) ipc_port_release_send(task->itk_bootstrap); + if (IP_VALID(task->itk_seatbelt)) + ipc_port_release_send(task->itk_seatbelt); + + if (IP_VALID(task->itk_gssd)) + ipc_port_release_send(task->itk_gssd); + + if (IP_VALID(task->itk_task_access)) + ipc_port_release_send(task->itk_task_access); + + if (IP_VALID(task->itk_debug_control)) + ipc_port_release_send(task->itk_debug_control); + for (i = 0; i < TASK_PORT_REGISTER_MAX; i++) if (IP_VALID(task->itk_registered[i])) ipc_port_release_send(task->itk_registered[i]); - ipc_port_release_send(task->wired_ledger_port); - ipc_port_release_send(task->paged_ledger_port); - - /* destroy the kernel port */ + /* destroy the kernel ports */ ipc_port_dealloc_kernel(kport); + ipc_port_dealloc_kernel(nport); + if (rport != IP_NULL) + ipc_port_dealloc_kernel(rport); + + itk_lock_destroy(task); } /* * Routine: ipc_task_reset * Purpose: * Reset a task's IPC state to protect it when - * it enters an elevated security context. + * it enters an elevated security context. The + * task name port can remain the same - since + * it represents no specific privilege. * Conditions: * Nothing locked. The task must be suspended. * (Or the current thread must be in the task.) @@ -290,6 +401,11 @@ ipc_task_reset( ipc_port_t old_exc_actions[EXC_TYPES_COUNT]; int i; +#if CONFIG_MACF + /* Fresh label to unset credentials in existing labels. */ + struct label *unset_label = mac_exc_create_label(); +#endif + new_kport = ipc_port_alloc_kernel(); if (new_kport == IP_NULL) panic("ipc_task_reset"); @@ -302,26 +418,51 @@ ipc_task_reset( /* the task is already terminated (can this happen?) */ itk_unlock(task); ipc_port_dealloc_kernel(new_kport); +#if CONFIG_MACF + mac_exc_free_label(unset_label); +#endif return; } task->itk_self = new_kport; old_sself = task->itk_sself; task->itk_sself = ipc_port_make_send(new_kport); - ipc_kobject_set(old_kport, IKO_NULL, IKOT_NONE); + + /* Set the old kport to IKOT_NONE and update the exec token while under the port lock */ + ip_lock(old_kport); + ipc_kobject_set_atomically(old_kport, IKO_NULL, IKOT_NONE); + task->exec_token += 1; + ip_unlock(old_kport); + ipc_kobject_set(new_kport, (ipc_kobject_t) task, IKOT_TASK); for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) { + old_exc_actions[i] = IP_NULL; + + if (i == EXC_CORPSE_NOTIFY && task_corpse_pending_report(task)) { + continue; + } + if (!task->exc_actions[i].privileged) { +#if CONFIG_MACF + mac_exc_update_action_label(task->exc_actions + i, unset_label); +#endif old_exc_actions[i] = task->exc_actions[i].port; task->exc_actions[i].port = IP_NULL; - } else { - old_exc_actions[i] = IP_NULL; } }/* for */ - + + if (IP_VALID(task->itk_debug_control)) { + ipc_port_release_send(task->itk_debug_control); + } + task->itk_debug_control = IP_NULL; + itk_unlock(task); +#if CONFIG_MACF + mac_exc_free_label(unset_label); +#endif + /* release the naked send rights */ if (IP_VALID(old_sself)) @@ -350,7 +491,6 @@ ipc_thread_init( thread_t thread) { ipc_port_t kport; - int i; kport = ipc_port_alloc_kernel(); if (kport == IP_NULL) @@ -358,17 +498,53 @@ ipc_thread_init( thread->ith_self = kport; thread->ith_sself = ipc_port_make_send(kport); - - for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) - thread->exc_actions[i].port = IP_NULL; + thread->ith_special_reply_port = NULL; + thread->exc_actions = NULL; ipc_kobject_set(kport, (ipc_kobject_t)thread, IKOT_THREAD); +#if IMPORTANCE_INHERITANCE + thread->ith_assertions = 0; +#endif + ipc_kmsg_queue_init(&thread->ith_messages); thread->ith_rpc_reply = IP_NULL; } +void +ipc_thread_init_exc_actions( + thread_t thread) +{ + assert(thread->exc_actions == NULL); + + thread->exc_actions = kalloc(sizeof(struct exception_action) * EXC_TYPES_COUNT); + bzero(thread->exc_actions, sizeof(struct exception_action) * EXC_TYPES_COUNT); + +#if CONFIG_MACF + for (size_t i = 0; i < EXC_TYPES_COUNT; ++i) { + mac_exc_associate_action_label(thread->exc_actions + i, mac_exc_create_label()); + } +#endif +} + +void +ipc_thread_destroy_exc_actions( + thread_t thread) +{ + if (thread->exc_actions != NULL) { +#if CONFIG_MACF + for (size_t i = 0; i < EXC_TYPES_COUNT; ++i) { + mac_exc_free_action_label(thread->exc_actions + i); + } +#endif + + kfree(thread->exc_actions, + sizeof(struct exception_action) * EXC_TYPES_COUNT); + thread->exc_actions = NULL; + } +} + void ipc_thread_disable( thread_t thread) @@ -401,14 +577,26 @@ ipc_thread_terminate( thread->ith_sself = thread->ith_self = IP_NULL; - for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) { - if (IP_VALID(thread->exc_actions[i].port)) - ipc_port_release_send(thread->exc_actions[i].port); - } + if (thread->exc_actions != NULL) { + for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) { + if (IP_VALID(thread->exc_actions[i].port)) + ipc_port_release_send(thread->exc_actions[i].port); + } + ipc_thread_destroy_exc_actions(thread); + } ipc_port_dealloc_kernel(kport); } +#if IMPORTANCE_INHERITANCE + assert(thread->ith_assertions == 0); +#endif + + /* unbind the thread special reply port */ + if (IP_VALID(thread->ith_special_reply_port)) { + ipc_port_unbind_special_reply_port(thread, TRUE); + } + assert(ipc_kmsg_queue_empty(&thread->ith_messages)); if (thread->ith_rpc_reply != IP_NULL) @@ -436,8 +624,13 @@ ipc_thread_reset( ipc_port_t old_kport, new_kport; ipc_port_t old_sself; ipc_port_t old_exc_actions[EXC_TYPES_COUNT]; - int i; + boolean_t has_old_exc_actions = FALSE; + int i; +#if CONFIG_MACF + struct label *new_label = mac_exc_create_label(); +#endif + new_kport = ipc_port_alloc_kernel(); if (new_kport == IP_NULL) panic("ipc_task_reset"); @@ -446,43 +639,69 @@ ipc_thread_reset( old_kport = thread->ith_self; - if (old_kport == IP_NULL) { + if (old_kport == IP_NULL && thread->inspection == FALSE) { /* the is already terminated (can this happen?) */ thread_mtx_unlock(thread); ipc_port_dealloc_kernel(new_kport); +#if CONFIG_MACF + mac_exc_free_label(new_label); +#endif return; } thread->ith_self = new_kport; old_sself = thread->ith_sself; thread->ith_sself = ipc_port_make_send(new_kport); - ipc_kobject_set(old_kport, IKO_NULL, IKOT_NONE); + if (old_kport != IP_NULL) { + ipc_kobject_set(old_kport, IKO_NULL, IKOT_NONE); + } ipc_kobject_set(new_kport, (ipc_kobject_t) thread, IKOT_THREAD); - for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) { - if (!thread->exc_actions[i].privileged) { - old_exc_actions[i] = thread->exc_actions[i].port; - thread->exc_actions[i].port = IP_NULL; - } else { - old_exc_actions[i] = IP_NULL; + /* + * Only ports that were set by root-owned processes + * (privileged ports) should survive + */ + if (thread->exc_actions != NULL) { + has_old_exc_actions = TRUE; + for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) { + if (thread->exc_actions[i].privileged) { + old_exc_actions[i] = IP_NULL; + } else { +#if CONFIG_MACF + mac_exc_update_action_label(thread->exc_actions + i, new_label); +#endif + old_exc_actions[i] = thread->exc_actions[i].port; + thread->exc_actions[i].port = IP_NULL; + } } - }/* for */ + } thread_mtx_unlock(thread); +#if CONFIG_MACF + mac_exc_free_label(new_label); +#endif + /* release the naked send rights */ if (IP_VALID(old_sself)) ipc_port_release_send(old_sself); - for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) { - if (IP_VALID(old_exc_actions[i])) { + if (has_old_exc_actions) { + for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) { ipc_port_release_send(old_exc_actions[i]); } - }/* for */ + } /* destroy the kernel port */ - ipc_port_dealloc_kernel(old_kport); + if (old_kport != IP_NULL) { + ipc_port_dealloc_kernel(old_kport); + } + + /* unbind the thread special reply port */ + if (IP_VALID(thread->ith_special_reply_port)) { + ipc_port_unbind_special_reply_port(thread, TRUE); + } } /* @@ -499,9 +718,9 @@ ipc_thread_reset( ipc_port_t retrieve_task_self_fast( - register task_t task) + task_t task) { - register ipc_port_t port; + ipc_port_t port; assert(task == current_task()); @@ -539,7 +758,7 @@ ipc_port_t retrieve_thread_self_fast( thread_t thread) { - register ipc_port_t port; + ipc_port_t port; assert(thread == current_thread()); @@ -641,6 +860,101 @@ mach_reply_port( return name; } +/* + * Routine: thread_get_special_reply_port [mach trap] + * Purpose: + * Allocate a special reply port for the calling thread. + * Conditions: + * Nothing locked. + * Returns: + * MACH_PORT_NULL if there are any resource failures + * or other errors. + */ + +mach_port_name_t +thread_get_special_reply_port( + __unused struct thread_get_special_reply_port_args *args) +{ + ipc_port_t port; + mach_port_name_t name; + kern_return_t kr; + thread_t thread = current_thread(); + + /* unbind the thread special reply port */ + if (IP_VALID(thread->ith_special_reply_port)) { + kr = ipc_port_unbind_special_reply_port(thread, TRUE); + if (kr != KERN_SUCCESS) { + return MACH_PORT_NULL; + } + } + + kr = ipc_port_alloc(current_task()->itk_space, &name, &port); + if (kr == KERN_SUCCESS) { + ipc_port_bind_special_reply_port_locked(port); + ip_unlock(port); + } else { + name = MACH_PORT_NULL; + } + return name; +} + +/* + * Routine: ipc_port_bind_special_reply_port_locked + * Purpose: + * Bind the given port to current thread as a special reply port. + * Conditions: + * Port locked. + * Returns: + * None. + */ + +static void +ipc_port_bind_special_reply_port_locked( + ipc_port_t port) +{ + thread_t thread = current_thread(); + assert(thread->ith_special_reply_port == NULL); + + ip_reference(port); + thread->ith_special_reply_port = port; + port->ip_specialreply = 1; + port->ip_link_sync_qos = 1; +} + +/* + * Routine: ipc_port_unbind_special_reply_port + * Purpose: + * Unbind the thread's special reply port. + * If the special port is linked to a port, adjust it's sync qos delta`. + * Condition: + * Nothing locked. + * Returns: + * None. + */ +static kern_return_t +ipc_port_unbind_special_reply_port( + thread_t thread, + boolean_t unbind_active_port) +{ + ipc_port_t special_reply_port = thread->ith_special_reply_port; + + ip_lock(special_reply_port); + + /* Return error if port active and unbind_active_port set to FALSE */ + if (unbind_active_port == FALSE && ip_active(special_reply_port)) { + ip_unlock(special_reply_port); + return KERN_FAILURE; + } + + thread->ith_special_reply_port = NULL; + ipc_port_unlink_special_reply_port_locked(special_reply_port, NULL, + IPC_PORT_UNLINK_SR_CLEAR_SPECIAL_REPLY); + /* port unlocked */ + + ip_release(special_reply_port); + return KERN_SUCCESS; +} + /* * Routine: thread_get_special_port [kernel call] * Purpose: @@ -763,44 +1077,50 @@ task_get_special_port( int which, ipc_port_t *portp) { - ipc_port_t *whichp; ipc_port_t port; if (task == TASK_NULL) return KERN_INVALID_ARGUMENT; + itk_lock(task); + if (task->itk_self == IP_NULL) { + itk_unlock(task); + return KERN_FAILURE; + } + switch (which) { - case TASK_KERNEL_PORT: - whichp = &task->itk_sself; + case TASK_KERNEL_PORT: + port = ipc_port_copy_send(task->itk_sself); break; - case TASK_HOST_PORT: - whichp = &task->itk_host; + case TASK_NAME_PORT: + port = ipc_port_make_send(task->itk_nself); break; - case TASK_BOOTSTRAP_PORT: - whichp = &task->itk_bootstrap; + case TASK_HOST_PORT: + port = ipc_port_copy_send(task->itk_host); break; - case TASK_WIRED_LEDGER_PORT: - whichp = &task->wired_ledger_port; - break; + case TASK_BOOTSTRAP_PORT: + port = ipc_port_copy_send(task->itk_bootstrap); + break; - case TASK_PAGED_LEDGER_PORT: - whichp = &task->paged_ledger_port; - break; - - default: - return KERN_INVALID_ARGUMENT; - } + case TASK_SEATBELT_PORT: + port = ipc_port_copy_send(task->itk_seatbelt); + break; - itk_lock(task); - if (task->itk_self == IP_NULL) { - itk_unlock(task); - return KERN_FAILURE; - } + case TASK_ACCESS_PORT: + port = ipc_port_copy_send(task->itk_task_access); + break; + + case TASK_DEBUG_CONTROL_PORT: + port = ipc_port_copy_send(task->itk_debug_control); + break; - port = ipc_port_copy_send(*whichp); + default: + itk_unlock(task); + return KERN_INVALID_ARGUMENT; + } itk_unlock(task); *portp = port; @@ -820,6 +1140,7 @@ task_get_special_port( * KERN_INVALID_ARGUMENT The task is null. * KERN_FAILURE The task/space is dead. * KERN_INVALID_ARGUMENT Invalid special port. + * KERN_NO_ACCESS Attempted overwrite of seatbelt port. */ kern_return_t @@ -835,28 +1156,32 @@ task_set_special_port( return KERN_INVALID_ARGUMENT; switch (which) { - case TASK_KERNEL_PORT: - whichp = &task->itk_sself; - break; + case TASK_KERNEL_PORT: + whichp = &task->itk_sself; + break; - case TASK_HOST_PORT: - whichp = &task->itk_host; - break; + case TASK_HOST_PORT: + whichp = &task->itk_host; + break; - case TASK_BOOTSTRAP_PORT: - whichp = &task->itk_bootstrap; - break; + case TASK_BOOTSTRAP_PORT: + whichp = &task->itk_bootstrap; + break; - case TASK_WIRED_LEDGER_PORT: - whichp = &task->wired_ledger_port; - break; + case TASK_SEATBELT_PORT: + whichp = &task->itk_seatbelt; + break; - case TASK_PAGED_LEDGER_PORT: - whichp = &task->paged_ledger_port; - break; - - default: - return KERN_INVALID_ARGUMENT; + case TASK_ACCESS_PORT: + whichp = &task->itk_task_access; + break; + + case TASK_DEBUG_CONTROL_PORT: + whichp = &task->itk_debug_control; + break; + + default: + return KERN_INVALID_ARGUMENT; }/* switch */ itk_lock(task); @@ -865,6 +1190,13 @@ task_set_special_port( return KERN_FAILURE; } + /* do not allow overwrite of seatbelt or task access ports */ + if ((TASK_SEATBELT_PORT == which || TASK_ACCESS_PORT == which) + && IP_VALID(*whichp)) { + itk_unlock(task); + return KERN_NO_ACCESS; + } + old = *whichp; *whichp = port; itk_unlock(task); @@ -891,6 +1223,7 @@ task_set_special_port( * KERN_SUCCESS Stashed the port rights. * KERN_INVALID_ARGUMENT The task is null. * KERN_INVALID_ARGUMENT The task is dead. + * KERN_INVALID_ARGUMENT The memory param is null. * KERN_INVALID_ARGUMENT Too many port rights supplied. */ @@ -904,7 +1237,8 @@ mach_ports_register( unsigned int i; if ((task == TASK_NULL) || - (portsCnt > TASK_PORT_REGISTER_MAX)) + (portsCnt > TASK_PORT_REGISTER_MAX) || + (portsCnt && memory == NULL)) return KERN_INVALID_ARGUMENT; /* @@ -1012,6 +1346,50 @@ mach_ports_lookup( return KERN_SUCCESS; } +kern_return_t +task_conversion_eval(task_t caller, task_t victim) +{ + /* + * Tasks are allowed to resolve their own task ports, and the kernel is + * allowed to resolve anyone's task port. + */ + if (caller == kernel_task) { + return KERN_SUCCESS; + } + + if (caller == victim) { + return KERN_SUCCESS; + } + + /* + * Only the kernel can can resolve the kernel's task port. We've established + * by this point that the caller is not kernel_task. + */ + if (victim == kernel_task) { + return KERN_INVALID_SECURITY; + } + +#if CONFIG_EMBEDDED + /* + * On embedded platforms, only a platform binary can resolve the task port + * of another platform binary. + */ + if ((victim->t_flags & TF_PLATFORM) && !(caller->t_flags & TF_PLATFORM)) { +#if SECURE_KERNEL + return KERN_INVALID_SECURITY; +#else + if (cs_relax_platform_task_ports) { + return KERN_SUCCESS; + } else { + return KERN_INVALID_SECURITY; + } +#endif /* SECURE_KERNEL */ + } +#endif /* CONFIG_EMBEDDED */ + + return KERN_SUCCESS; +} + /* * Routine: convert_port_to_locked_task * Purpose: @@ -1024,7 +1402,10 @@ mach_ports_lookup( task_t convert_port_to_locked_task(ipc_port_t port) { + int try_failed_count = 0; + while (IP_VALID(port)) { + task_t ct = current_task(); task_t task; ip_lock(port); @@ -1035,6 +1416,11 @@ convert_port_to_locked_task(ipc_port_t port) task = (task_t) port->ip_kobject; assert(task != TASK_NULL); + if (task_conversion_eval(ct, task)) { + ip_unlock(port); + return TASK_NULL; + } + /* * Normal lock ordering puts task_lock() before ip_lock(). * Attempt out-of-order locking here. @@ -1043,13 +1429,55 @@ convert_port_to_locked_task(ipc_port_t port) ip_unlock(port); return(task); } + try_failed_count++; ip_unlock(port); - mutex_pause(); + mutex_pause(try_failed_count); } return TASK_NULL; } +/* + * Routine: convert_port_to_locked_task_inspect + * Purpose: + * Internal helper routine to convert from a port to a locked + * task inspect right. Used by internal routines that try to convert from a + * task inspect port to a reference on some task related object. + * Conditions: + * Nothing locked, blocking OK. + */ +task_inspect_t +convert_port_to_locked_task_inspect(ipc_port_t port) +{ + int try_failed_count = 0; + + while (IP_VALID(port)) { + task_inspect_t task; + + ip_lock(port); + if (!ip_active(port) || (ip_kotype(port) != IKOT_TASK)) { + ip_unlock(port); + return TASK_INSPECT_NULL; + } + task = (task_inspect_t)port->ip_kobject; + assert(task != TASK_INSPECT_NULL); + /* + * Normal lock ordering puts task_lock() before ip_lock(). + * Attempt out-of-order locking here. + */ + if (task_lock_try((task_t)task)) { + ip_unlock(port); + return task; + } + try_failed_count++; + + ip_unlock(port); + mutex_pause(try_failed_count); + } + return TASK_INSPECT_NULL; +} + + /* * Routine: convert_port_to_task * Purpose: @@ -1062,6 +1490,24 @@ convert_port_to_locked_task(ipc_port_t port) task_t convert_port_to_task( ipc_port_t port) +{ + return convert_port_to_task_with_exec_token(port, NULL); +} + +/* + * Routine: convert_port_to_task_with_exec_token + * Purpose: + * Convert from a port to a task and return + * the exec token stored in the task. + * Doesn't consume the port ref; produces a task ref, + * which may be null. + * Conditions: + * Nothing locked. + */ +task_t +convert_port_to_task_with_exec_token( + ipc_port_t port, + uint32_t *exec_token) { task_t task = TASK_NULL; @@ -1070,9 +1516,115 @@ convert_port_to_task( if ( ip_active(port) && ip_kotype(port) == IKOT_TASK ) { + task_t ct = current_task(); task = (task_t)port->ip_kobject; assert(task != TASK_NULL); + if (task_conversion_eval(ct, task)) { + ip_unlock(port); + return TASK_NULL; + } + + if (exec_token) { + *exec_token = task->exec_token; + } + task_reference_internal(task); + } + + ip_unlock(port); + } + + return (task); +} + +/* + * Routine: convert_port_to_task_name + * Purpose: + * Convert from a port to a task name. + * Doesn't consume the port ref; produces a task name ref, + * which may be null. + * Conditions: + * Nothing locked. + */ +task_name_t +convert_port_to_task_name( + ipc_port_t port) +{ + task_name_t task = TASK_NULL; + + if (IP_VALID(port)) { + ip_lock(port); + + if ( ip_active(port) && + (ip_kotype(port) == IKOT_TASK || + ip_kotype(port) == IKOT_TASK_NAME)) { + task = (task_name_t)port->ip_kobject; + assert(task != TASK_NAME_NULL); + + task_reference_internal(task); + } + + ip_unlock(port); + } + + return (task); +} + +/* + * Routine: convert_port_to_task_inspect + * Purpose: + * Convert from a port to a task inspection right + * Doesn't consume the port ref; produces a task ref, + * which may be null. + * Conditions: + * Nothing locked. + */ +task_inspect_t +convert_port_to_task_inspect( + ipc_port_t port) +{ + task_inspect_t task = TASK_INSPECT_NULL; + + if (IP_VALID(port)) { + ip_lock(port); + + if (ip_active(port) && + ip_kotype(port) == IKOT_TASK) { + task = (task_inspect_t)port->ip_kobject; + assert(task != TASK_INSPECT_NULL); + + task_reference_internal(task); + } + + ip_unlock(port); + } + + return (task); +} + +/* + * Routine: convert_port_to_task_suspension_token + * Purpose: + * Convert from a port to a task suspension token. + * Doesn't consume the port ref; produces a suspension token ref, + * which may be null. + * Conditions: + * Nothing locked. + */ +task_suspension_token_t +convert_port_to_task_suspension_token( + ipc_port_t port) +{ + task_suspension_token_t task = TASK_NULL; + + if (IP_VALID(port)) { + ip_lock(port); + + if ( ip_active(port) && + ip_kotype(port) == IKOT_TASK_RESUME) { + task = (task_suspension_token_t)port->ip_kobject; + assert(task != TASK_NULL); + task_reference_internal(task); } @@ -1114,6 +1666,38 @@ convert_port_to_space( return (space); } +/* + * Routine: convert_port_to_space_inspect + * Purpose: + * Convert from a port to a space inspect right. + * Doesn't consume the port ref; produces a space inspect ref, + * which may be null. + * Conditions: + * Nothing locked. + */ +ipc_space_inspect_t +convert_port_to_space_inspect( + ipc_port_t port) +{ + ipc_space_inspect_t space; + task_inspect_t task; + + task = convert_port_to_locked_task_inspect(port); + + if (task == TASK_INSPECT_NULL) + return IPC_SPACE_INSPECT_NULL; + + if (!task->active) { + task_unlock(task); + return IPC_SPACE_INSPECT_NULL; + } + + space = (ipc_space_inspect_t)task->itk_space; + is_reference((ipc_space_t)space); + task_unlock((task_t)task); + return space; +} + /* * Routine: convert_port_to_map * Purpose: @@ -1171,6 +1755,11 @@ convert_port_to_thread( ip_kotype(port) == IKOT_THREAD ) { thread = (thread_t)port->ip_kobject; assert(thread != THREAD_NULL); + if (thread->task && thread->task == kernel_task && + current_task() != kernel_task) { + ip_unlock(port); + return THREAD_NULL; + } thread_reference_internal(thread); } @@ -1181,6 +1770,55 @@ convert_port_to_thread( return (thread); } +/* + * Routine: convert_port_to_thread_inspect + * Purpose: + * Convert from a port to a thread inspection right + * Doesn't consume the port ref; produces a thread ref, + * which may be null. + * Conditions: + * Nothing locked. + */ +thread_inspect_t +convert_port_to_thread_inspect( + ipc_port_t port) +{ + thread_inspect_t thread = THREAD_INSPECT_NULL; + + if (IP_VALID(port)) { + ip_lock(port); + + if (ip_active(port) && + ip_kotype(port) == IKOT_THREAD) { + thread = (thread_inspect_t)port->ip_kobject; + assert(thread != THREAD_INSPECT_NULL); + thread_reference_internal((thread_t)thread); + } + ip_unlock(port); + } + + return thread; +} + +/* + * Routine: convert_thread_inspect_to_port + * Purpose: + * Convert from a thread inspect reference to a port. + * Consumes a thread ref; + * As we never export thread inspect ports, always + * creates a NULL port. + * Conditions: + * Nothing locked. + */ + +ipc_port_t +convert_thread_inspect_to_port(thread_inspect_t thread) +{ + thread_deallocate(thread); + return IP_NULL; +} + + /* * Routine: port_name_to_thread * Purpose: @@ -1188,6 +1826,9 @@ convert_port_to_thread( * A name of MACH_PORT_NULL is valid for the null thread. * Conditions: * Nothing locked. + * + * TODO: Could this be faster if it were ipc_port_translate_send based, like thread_switch? + * We could avoid extra lock/unlock and extra ref operations on the port. */ thread_t port_name_to_thread( @@ -1234,6 +1875,56 @@ port_name_to_task( return task; } +task_inspect_t +port_name_to_task_inspect( + mach_port_name_t name) +{ + ipc_port_t kern_port; + kern_return_t kr; + task_inspect_t ti = TASK_INSPECT_NULL; + + if (MACH_PORT_VALID(name)) { + kr = ipc_object_copyin(current_space(), name, + MACH_MSG_TYPE_COPY_SEND, + (ipc_object_t *)&kern_port); + if (kr != KERN_SUCCESS) + return TASK_NULL; + + ti = convert_port_to_task_inspect(kern_port); + + if (IP_VALID(kern_port)) + ipc_port_release_send(kern_port); + } + return ti; +} + +/* + * Routine: port_name_to_host + * Purpose: + * Convert from a port name to a host pointer. + * NOTE: This does _not_ return a +1 reference to the host_t + * Conditions: + * Nothing locked. + */ +host_t +port_name_to_host( + mach_port_name_t name) +{ + + host_t host = HOST_NULL; + kern_return_t kr; + ipc_port_t port; + + if (MACH_PORT_VALID(name)) { + kr = ipc_port_translate_send(current_space(), name, &port); + if (kr == KERN_SUCCESS) { + host = convert_port_to_host(port); + ip_unlock(port); + } + } + return host; +} + /* * Routine: convert_task_to_port * Purpose: @@ -1251,16 +1942,108 @@ convert_task_to_port( ipc_port_t port; itk_lock(task); + if (task->itk_self != IP_NULL) port = ipc_port_make_send(task->itk_self); else port = IP_NULL; + itk_unlock(task); task_deallocate(task); return port; } +/* + * Routine: convert_task_inspect_to_port + * Purpose: + * Convert from a task inspect reference to a port. + * Consumes a task ref; + * As we never export task inspect ports, always + * creates a NULL port. + * Conditions: + * Nothing locked. + */ +ipc_port_t +convert_task_inspect_to_port( + task_inspect_t task) +{ + task_deallocate(task); + + return IP_NULL; +} + +/* + * Routine: convert_task_suspend_token_to_port + * Purpose: + * Convert from a task suspension token to a port. + * Consumes a task suspension token ref; produces a naked send-once right + * which may be invalid. + * Conditions: + * Nothing locked. + */ +ipc_port_t +convert_task_suspension_token_to_port( + task_suspension_token_t task) +{ + ipc_port_t port; + + task_lock(task); + if (task->active) { + if (task->itk_resume == IP_NULL) { + task->itk_resume = ipc_port_alloc_kernel(); + if (!IP_VALID(task->itk_resume)) { + panic("failed to create resume port"); + } + + ipc_kobject_set(task->itk_resume, (ipc_kobject_t) task, IKOT_TASK_RESUME); + } + + /* + * Create a send-once right for each instance of a direct user-called + * task_suspend2 call. Each time one of these send-once rights is abandoned, + * the notification handler will resume the target task. + */ + port = ipc_port_make_sonce(task->itk_resume); + assert(IP_VALID(port)); + } else { + port = IP_NULL; + } + + task_unlock(task); + task_suspension_token_deallocate(task); + + return port; +} + + +/* + * Routine: convert_task_name_to_port + * Purpose: + * Convert from a task name ref to a port. + * Consumes a task name ref; produces a naked send right + * which may be invalid. + * Conditions: + * Nothing locked. + */ + +ipc_port_t +convert_task_name_to_port( + task_name_t task_name) +{ + ipc_port_t port; + + itk_lock(task_name); + if (task_name->itk_nself != IP_NULL) + port = ipc_port_make_send(task_name->itk_nself); + else + port = IP_NULL; + itk_unlock(task_name); + + task_name_deallocate(task_name); + return port; +} + /* * Routine: convert_thread_to_port * Purpose: @@ -1307,6 +2090,22 @@ space_deallocate( is_release(space); } +/* + * Routine: space_inspect_deallocate + * Purpose: + * Deallocate a space inspect ref produced by convert_port_to_space_inspect. + * Conditions: + * Nothing locked. + */ + +void +space_inspect_deallocate( + ipc_space_inspect_t space) +{ + if (space != IS_INSPECT_NULL) + is_release((ipc_space_t)space); +} + /* * Routine: thread/task_set_exception_ports [kernel call] * Purpose: @@ -1337,14 +2136,18 @@ thread_set_exception_ports( boolean_t privileged = current_task()->sec_token.val[0] == 0; register int i; +#if CONFIG_MACF + struct label *new_label; +#endif + if (thread == THREAD_NULL) return (KERN_INVALID_ARGUMENT); - if (exception_mask & ~EXC_MASK_ALL) + if (exception_mask & ~EXC_MASK_VALID) return (KERN_INVALID_ARGUMENT); if (IP_VALID(new_port)) { - switch (new_behavior) { + switch (new_behavior & ~MACH_EXCEPTION_CODES) { case EXCEPTION_DEFAULT: case EXCEPTION_STATE: @@ -1361,9 +2164,13 @@ thread_set_exception_ports( * VALID_THREAD_STATE_FLAVOR architecture dependent macro defined in * osfmk/mach/ARCHITECTURE/thread_status.h */ - if (!VALID_THREAD_STATE_FLAVOR(new_flavor)) + if (new_flavor != 0 && !VALID_THREAD_STATE_FLAVOR(new_flavor)) return (KERN_INVALID_ARGUMENT); +#if CONFIG_MACF + new_label = mac_exc_create_label_for_current_proc(); +#endif + thread_mtx_lock(thread); if (!thread->active) { @@ -1372,8 +2179,15 @@ thread_set_exception_ports( return (KERN_FAILURE); } + if (thread->exc_actions == NULL) { + ipc_thread_init_exc_actions(thread); + } for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) { - if (exception_mask & (1 << i)) { + if ((exception_mask & (1 << i)) +#if CONFIG_MACF + && mac_exc_update_action_label(&thread->exc_actions[i], new_label) == 0 +#endif + ) { old_port[i] = thread->exc_actions[i].port; thread->exc_actions[i].port = ipc_port_copy_send(new_port); thread->exc_actions[i].behavior = new_behavior; @@ -1386,6 +2200,10 @@ thread_set_exception_ports( thread_mtx_unlock(thread); +#if CONFIG_MACF + mac_exc_free_label(new_label); +#endif + for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) if (IP_VALID(old_port[i])) ipc_port_release_send(old_port[i]); @@ -1408,14 +2226,18 @@ task_set_exception_ports( boolean_t privileged = current_task()->sec_token.val[0] == 0; register int i; +#if CONFIG_MACF + struct label *new_label; +#endif + if (task == TASK_NULL) return (KERN_INVALID_ARGUMENT); - if (exception_mask & ~EXC_MASK_ALL) + if (exception_mask & ~EXC_MASK_VALID) return (KERN_INVALID_ARGUMENT); if (IP_VALID(new_port)) { - switch (new_behavior) { + switch (new_behavior & ~MACH_EXCEPTION_CODES) { case EXCEPTION_DEFAULT: case EXCEPTION_STATE: @@ -1427,6 +2249,18 @@ task_set_exception_ports( } } + /* + * Check the validity of the thread_state_flavor by calling the + * VALID_THREAD_STATE_FLAVOR architecture dependent macro defined in + * osfmk/mach/ARCHITECTURE/thread_status.h + */ + if (new_flavor != 0 && !VALID_THREAD_STATE_FLAVOR(new_flavor)) + return (KERN_INVALID_ARGUMENT); + +#if CONFIG_MACF + new_label = mac_exc_create_label_for_current_proc(); +#endif + itk_lock(task); if (task->itk_self == IP_NULL) { @@ -1436,7 +2270,11 @@ task_set_exception_ports( } for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) { - if (exception_mask & (1 << i)) { + if ((exception_mask & (1 << i)) +#if CONFIG_MACF + && mac_exc_update_action_label(&task->exc_actions[i], new_label) == 0 +#endif + ) { old_port[i] = task->exc_actions[i].port; task->exc_actions[i].port = ipc_port_copy_send(new_port); @@ -1450,6 +2288,10 @@ task_set_exception_ports( itk_unlock(task); +#if CONFIG_MACF + mac_exc_free_label(new_label); +#endif + for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) if (IP_VALID(old_port[i])) ipc_port_release_send(old_port[i]); @@ -1504,14 +2346,18 @@ thread_swap_exception_ports( boolean_t privileged = current_task()->sec_token.val[0] == 0; unsigned int i, j, count; +#if CONFIG_MACF + struct label *new_label; +#endif + if (thread == THREAD_NULL) return (KERN_INVALID_ARGUMENT); - if (exception_mask & ~EXC_MASK_ALL) + if (exception_mask & ~EXC_MASK_VALID) return (KERN_INVALID_ARGUMENT); if (IP_VALID(new_port)) { - switch (new_behavior) { + switch (new_behavior & ~MACH_EXCEPTION_CODES) { case EXCEPTION_DEFAULT: case EXCEPTION_STATE: @@ -1523,6 +2369,13 @@ thread_swap_exception_ports( } } + if (new_flavor != 0 && !VALID_THREAD_STATE_FLAVOR(new_flavor)) + return (KERN_INVALID_ARGUMENT); + +#if CONFIG_MACF + new_label = mac_exc_create_label_for_current_proc(); +#endif + thread_mtx_lock(thread); if (!thread->active) { @@ -1531,10 +2384,17 @@ thread_swap_exception_ports( return (KERN_FAILURE); } - count = 0; + if (thread->exc_actions == NULL) { + ipc_thread_init_exc_actions(thread); + } - for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) { - if (exception_mask & (1 << i)) { + assert(EXC_TYPES_COUNT > FIRST_EXCEPTION); + for (count = 0, i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT && count < *CountCnt; ++i) { + if ((exception_mask & (1 << i)) +#if CONFIG_MACF + && mac_exc_update_action_label(&thread->exc_actions[i], new_label) == 0 +#endif + ) { for (j = 0; j < count; ++j) { /* * search for an identical entry, if found @@ -1562,8 +2422,6 @@ thread_swap_exception_ports( thread->exc_actions[i].behavior = new_behavior; thread->exc_actions[i].flavor = new_flavor; thread->exc_actions[i].privileged = privileged; - if (count > *CountCnt) - break; } else old_port[i] = IP_NULL; @@ -1571,9 +2429,14 @@ thread_swap_exception_ports( thread_mtx_unlock(thread); - for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) +#if CONFIG_MACF + mac_exc_free_label(new_label); +#endif + + while (--i >= FIRST_EXCEPTION) { if (IP_VALID(old_port[i])) ipc_port_release_send(old_port[i]); + } if (IP_VALID(new_port)) /* consume send right */ ipc_port_release_send(new_port); @@ -1600,14 +2463,18 @@ task_swap_exception_ports( boolean_t privileged = current_task()->sec_token.val[0] == 0; unsigned int i, j, count; +#if CONFIG_MACF + struct label *new_label; +#endif + if (task == TASK_NULL) return (KERN_INVALID_ARGUMENT); - if (exception_mask & ~EXC_MASK_ALL) + if (exception_mask & ~EXC_MASK_VALID) return (KERN_INVALID_ARGUMENT); if (IP_VALID(new_port)) { - switch (new_behavior) { + switch (new_behavior & ~MACH_EXCEPTION_CODES) { case EXCEPTION_DEFAULT: case EXCEPTION_STATE: @@ -1619,6 +2486,13 @@ task_swap_exception_ports( } } + if (new_flavor != 0 && !VALID_THREAD_STATE_FLAVOR(new_flavor)) + return (KERN_INVALID_ARGUMENT); + +#if CONFIG_MACF + new_label = mac_exc_create_label_for_current_proc(); +#endif + itk_lock(task); if (task->itk_self == IP_NULL) { @@ -1627,10 +2501,13 @@ task_swap_exception_ports( return (KERN_FAILURE); } - count = 0; - - for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) { - if (exception_mask & (1 << i)) { + assert(EXC_TYPES_COUNT > FIRST_EXCEPTION); + for (count = 0, i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT && count < *CountCnt; ++i) { + if ((exception_mask & (1 << i)) +#if CONFIG_MACF + && mac_exc_update_action_label(&task->exc_actions[i], new_label) == 0 +#endif + ) { for (j = 0; j < count; j++) { /* * search for an identical entry, if found @@ -1653,12 +2530,11 @@ task_swap_exception_ports( } old_port[i] = task->exc_actions[i].port; + task->exc_actions[i].port = ipc_port_copy_send(new_port); task->exc_actions[i].behavior = new_behavior; task->exc_actions[i].flavor = new_flavor; task->exc_actions[i].privileged = privileged; - if (count > *CountCnt) - break; } else old_port[i] = IP_NULL; @@ -1666,9 +2542,14 @@ task_swap_exception_ports( itk_unlock(task); - for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; i++) +#if CONFIG_MACF + mac_exc_free_label(new_label); +#endif + + while (--i >= FIRST_EXCEPTION) { if (IP_VALID(old_port[i])) ipc_port_release_send(old_port[i]); + } if (IP_VALID(new_port)) /* consume send right */ ipc_port_release_send(new_port); @@ -1712,7 +2593,7 @@ thread_get_exception_ports( if (thread == THREAD_NULL) return (KERN_INVALID_ARGUMENT); - if (exception_mask & ~EXC_MASK_ALL) + if (exception_mask & ~EXC_MASK_VALID) return (KERN_INVALID_ARGUMENT); thread_mtx_lock(thread); @@ -1725,6 +2606,10 @@ thread_get_exception_ports( count = 0; + if (thread->exc_actions == NULL) { + goto done; + } + for (i = FIRST_EXCEPTION; i < EXC_TYPES_COUNT; ++i) { if (exception_mask & (1 << i)) { for (j = 0; j < count; ++j) { @@ -1752,6 +2637,7 @@ thread_get_exception_ports( } } +done: thread_mtx_unlock(thread); *CountCnt = count; @@ -1774,7 +2660,7 @@ task_get_exception_ports( if (task == TASK_NULL) return (KERN_INVALID_ARGUMENT); - if (exception_mask & ~EXC_MASK_ALL) + if (exception_mask & ~EXC_MASK_VALID) return (KERN_INVALID_ARGUMENT); itk_lock(task);