X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/ff6e181ae92fc6f1e89841290f461d1f2f9badd9..HEAD:/bsd/uxkern/ux_exception.c diff --git a/bsd/uxkern/ux_exception.c b/bsd/uxkern/ux_exception.c index f0fbf42e7..1ef01a1d4 100644 --- a/bsd/uxkern/ux_exception.c +++ b/bsd/uxkern/ux_exception.c @@ -1,15 +1,20 @@ /* - * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2017 Apple Inc. All rights reserved. + * + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * @APPLE_LICENSE_HEADER_START@ - * * 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. Please obtain a copy of the License at - * http://www.opensource.apple.com/apsl/ and read it before using this - * file. - * + * 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. + * + * 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, @@ -17,338 +22,159 @@ * 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@ */ -/* +/* * Mach Operating System * Copyright (c) 1987 Carnegie-Mellon University * All rights reserved. The CMU software License Agreement specifies * the terms and conditions for use and redistribution. */ -/* - ********************************************************************* - * HISTORY - ********************************************************************** - */ - #include #include #include #include -#include -#include -#include -#include -#include -#include -#include -#include -#include #include #include #include -#include - -#include /* get_task_ipcspace() */ - -/* - * XXX Things that should be retrieved from Mach headers, but aren't - */ -struct ipc_object; -extern kern_return_t ipc_object_copyin(ipc_space_t space, mach_port_name_t name, - mach_msg_type_name_t msgt_name, struct ipc_object **objectp); -extern mach_msg_return_t mach_msg_receive(mach_msg_header_t *msg, - mach_msg_option_t option, mach_msg_size_t rcv_size, - mach_port_name_t rcv_name, mach_msg_timeout_t rcv_timeout, - void (*continuation)(mach_msg_return_t), - mach_msg_size_t slist_size); -extern mach_msg_return_t mach_msg_send(mach_msg_header_t *msg, - mach_msg_option_t option, mach_msg_size_t send_size, - mach_msg_timeout_t send_timeout, mach_port_name_t notify); -extern thread_t convert_port_to_thread(ipc_port_t port); -extern void ipc_port_release(ipc_port_t); - - +#include /* MAXSSIZ */ +#include /* - * Unix exception handler. + * Translate Mach exceptions to UNIX signals. + * + * ux_exception translates a mach exception, code and subcode to + * a signal. Calls machine_exception (machine dependent) + * to attempt translation first. */ - -static void ux_exception(int exception, int code, int subcode, - int *ux_signal, int *ux_code); - -mach_port_name_t ux_exception_port; -static task_t ux_handler_self; - -static -void -ux_handler(void) +static int +ux_exception(int exception, + mach_exception_code_t code, + mach_exception_subcode_t subcode) { - task_t self = current_task(); - mach_port_name_t exc_port_name; - mach_port_name_t exc_set_name; - - (void) thread_funnel_set(kernel_flock, TRUE); - - /* self->kernel_vm_space = TRUE; */ - ux_handler_self = self; - - - /* - * Allocate a port set that we will receive on. - */ - if (mach_port_allocate(get_task_ipcspace(ux_handler_self), MACH_PORT_RIGHT_PORT_SET, &exc_set_name) != MACH_MSG_SUCCESS) - panic("ux_handler: port_set_allocate failed"); - - /* - * Allocate an exception port and use object_copyin to - * translate it to the global name. Put it into the set. - */ - if (mach_port_allocate(get_task_ipcspace(ux_handler_self), MACH_PORT_RIGHT_RECEIVE, &exc_port_name) != MACH_MSG_SUCCESS) - panic("ux_handler: port_allocate failed"); - if (mach_port_move_member(get_task_ipcspace(ux_handler_self), - exc_port_name, exc_set_name) != MACH_MSG_SUCCESS) - panic("ux_handler: port_set_add failed"); - - if (ipc_object_copyin(get_task_ipcspace(self), exc_port_name, - MACH_MSG_TYPE_MAKE_SEND, - (void *) &ux_exception_port) != MACH_MSG_SUCCESS) - panic("ux_handler: object_copyin(ux_exception_port) failed"); - - thread_wakeup(&ux_exception_port); - - /* Message handling loop. */ - - for (;;) { - struct rep_msg { - mach_msg_header_t Head; - NDR_record_t NDR; - kern_return_t RetCode; - } rep_msg; - struct exc_msg { - mach_msg_header_t Head; - /* start of the kernel processed data */ - mach_msg_body_t msgh_body; - mach_msg_port_descriptor_t thread; - mach_msg_port_descriptor_t task; - /* end of the kernel processed data */ - NDR_record_t NDR; - exception_type_t exception; - mach_msg_type_number_t codeCnt; - exception_data_t code; - /* some times RCV_TO_LARGE probs */ - char pad[512]; - } exc_msg; - mach_port_name_t reply_port; - kern_return_t result; + int machine_signal = 0; - exc_msg.Head.msgh_local_port = (mach_port_t)exc_set_name; - exc_msg.Head.msgh_size = sizeof (exc_msg); -#if 0 - result = mach_msg_receive(&exc_msg.Head); -#else - result = mach_msg_receive(&exc_msg.Head, MACH_RCV_MSG, - sizeof (exc_msg), exc_set_name, - MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL, - 0); -#endif - if (result == MACH_MSG_SUCCESS) { - reply_port = (mach_port_name_t)exc_msg.Head.msgh_remote_port; - - if (exc_server(&exc_msg.Head, &rep_msg.Head)) - (void) mach_msg_send(&rep_msg.Head, MACH_SEND_MSG, - sizeof (rep_msg),MACH_MSG_TIMEOUT_NONE,MACH_PORT_NULL); - - if (reply_port != MACH_PORT_NULL) - (void) mach_port_deallocate(get_task_ipcspace(ux_handler_self), reply_port); + /* Try machine-dependent translation first. */ + if ((machine_signal = machine_exception(exception, code, subcode)) != 0) { + return machine_signal; } - else if (result == MACH_RCV_TOO_LARGE) - /* ignore oversized messages */; - else - panic("exception_handler"); - } - thread_funnel_set(kernel_flock, FALSE); -} -void -ux_handler_init(void) -{ - ux_exception_port = MACH_PORT_NULL; - (void) kernel_thread(kernel_task, ux_handler); - if (ux_exception_port == MACH_PORT_NULL) { - assert_wait(&ux_exception_port, THREAD_UNINT); - thread_block(THREAD_CONTINUE_NULL); + switch (exception) { + case EXC_BAD_ACCESS: + if (code == KERN_INVALID_ADDRESS) { + return SIGSEGV; + } else { + return SIGBUS; } -} -kern_return_t -catch_exception_raise( - __unused mach_port_t exception_port, - mach_port_t thread, - mach_port_t task, - exception_type_t exception, - exception_data_t code, - __unused mach_msg_type_number_t codeCnt -) -{ - task_t self = current_task(); - thread_t th_act; - ipc_port_t thread_port; - kern_return_t result = MACH_MSG_SUCCESS; - int ux_signal = 0; - u_long ucode = 0; - struct uthread *ut; - mach_port_name_t thread_name = (mach_port_name_t)thread; /* XXX */ - mach_port_name_t task_name = (mach_port_name_t)task; /* XXX */ + case EXC_BAD_INSTRUCTION: + return SIGILL; - /* - * Convert local thread name to global port. - */ - if (MACH_PORT_VALID(thread_name) && - (ipc_object_copyin(get_task_ipcspace(self), thread_name, - MACH_MSG_TYPE_PORT_SEND, - (void *) &thread_port) == MACH_MSG_SUCCESS)) { - if (IPC_PORT_VALID(thread_port)) { - th_act = convert_port_to_thread(thread_port); - ipc_port_release(thread_port); - } else { - th_act = THREAD_NULL; - } + case EXC_ARITHMETIC: + return SIGFPE; - /* - * Catch bogus ports - */ - if (th_act != THREAD_NULL) { - - /* - * Convert exception to unix signal and code. - */ - ut = get_bsdthread_info(th_act); - ux_exception(exception, code[0], code[1], - &ux_signal, (int *)&ucode); + case EXC_EMULATION: + return SIGEMT; - /* - * Send signal. - */ - if (ux_signal != 0) - threadsignal(th_act, ux_signal, ucode); + case EXC_SOFTWARE: + switch (code) { + case EXC_UNIX_BAD_SYSCALL: + return SIGSYS; + case EXC_UNIX_BAD_PIPE: + return SIGPIPE; + case EXC_UNIX_ABORT: + return SIGABRT; + case EXC_SOFT_SIGNAL: + return SIGKILL; + } + break; - thread_deallocate(th_act); + case EXC_BREAKPOINT: + return SIGTRAP; } - else - result = KERN_INVALID_ARGUMENT; - } - else - result = KERN_INVALID_ARGUMENT; - - /* - * Delete our send rights to the task and thread ports. - */ - (void)mach_port_deallocate(get_task_ipcspace(ux_handler_self), task_name); - (void)mach_port_deallocate(get_task_ipcspace(ux_handler_self), thread_name); - return (result); -} - -kern_return_t -catch_exception_raise_state( - __unused mach_port_t exception_port, - __unused exception_type_t exception, - __unused const exception_data_t code, - __unused mach_msg_type_number_t codeCnt, - __unused int *flavor, - __unused const thread_state_t old_state, - __unused mach_msg_type_number_t old_stateCnt, - __unused thread_state_t new_state, - __unused mach_msg_type_number_t *new_stateCnt) -{ - return(KERN_INVALID_ARGUMENT); -} - -kern_return_t -catch_exception_raise_state_identity( - __unused mach_port_t exception_port, - __unused mach_port_t thread, - __unused mach_port_t task, - __unused exception_type_t exception, - __unused exception_data_t code, - __unused mach_msg_type_number_t codeCnt, - __unused int *flavor, - __unused thread_state_t old_state, - __unused mach_msg_type_number_t old_stateCnt, - __unused thread_state_t new_state, - __unused mach_msg_type_number_t *new_stateCnt) -{ - return(KERN_INVALID_ARGUMENT); + return 0; } /* - * ux_exception translates a mach exception, code and subcode to - * a signal and u.u_code. Calls machine_exception (machine dependent) - * to attempt translation first. + * Sends the corresponding UNIX signal to a thread that has triggered a Mach exception. */ - -static -void ux_exception( - int exception, - int code, - int subcode, - int *ux_signal, - int *ux_code -) +kern_return_t +handle_ux_exception(thread_t thread, + int exception, + mach_exception_code_t code, + mach_exception_subcode_t subcode) { - /* - * Try machine-dependent translation first. - */ - if (machine_exception(exception, code, subcode, ux_signal, ux_code)) - return; - - switch(exception) { + /* Returns +1 proc reference */ + proc_t p = proc_findthread(thread); - case EXC_BAD_ACCESS: - if (code == KERN_INVALID_ADDRESS) - *ux_signal = SIGSEGV; - else - *ux_signal = SIGBUS; - break; + /* Can't deliver a signal without a bsd process reference */ + if (p == NULL) { + return KERN_FAILURE; + } - case EXC_BAD_INSTRUCTION: - *ux_signal = SIGILL; - break; + /* Translate exception and code to signal type */ + int ux_signal = ux_exception(exception, code, subcode); - case EXC_ARITHMETIC: - *ux_signal = SIGFPE; - break; + uthread_t ut = get_bsdthread_info(thread); - case EXC_EMULATION: - *ux_signal = SIGEMT; - break; + /* + * Stack overflow should result in a SIGSEGV signal + * on the alternate stack. + * but we have one or more guard pages after the + * stack top, so we would get a KERN_PROTECTION_FAILURE + * exception instead of KERN_INVALID_ADDRESS, resulting in + * a SIGBUS signal. + * Detect that situation and select the correct signal. + */ + if (code == KERN_PROTECTION_FAILURE && + ux_signal == SIGBUS) { + user_addr_t sp = subcode; + + user_addr_t stack_max = p->user_stack; + user_addr_t stack_min = p->user_stack - MAXSSIZ; + if (sp >= stack_min && sp < stack_max) { + /* + * This is indeed a stack overflow. Deliver a + * SIGSEGV signal. + */ + ux_signal = SIGSEGV; + + /* + * If the thread/process is not ready to handle + * SIGSEGV on an alternate stack, force-deliver + * SIGSEGV with a SIG_DFL handler. + */ + int mask = sigmask(ux_signal); + struct sigacts *ps = p->p_sigacts; + if ((p->p_sigignore & mask) || + (ut->uu_sigwait & mask) || + (ut->uu_sigmask & mask) || + (ps->ps_sigact[SIGSEGV] == SIG_IGN) || + (!(ps->ps_sigonstack & mask))) { + p->p_sigignore &= ~mask; + p->p_sigcatch &= ~mask; + ps->ps_sigact[SIGSEGV] = SIG_DFL; + ut->uu_sigwait &= ~mask; + ut->uu_sigmask &= ~mask; + } + } + } - case EXC_SOFTWARE: - switch (code) { + /* Send signal to thread */ + if (ux_signal != 0) { + ut->uu_exception = exception; + //ut->uu_code = code; // filled in by threadsignal + ut->uu_subcode = subcode; + threadsignal(thread, ux_signal, code, TRUE); + } - case EXC_UNIX_BAD_SYSCALL: - *ux_signal = SIGSYS; - break; - case EXC_UNIX_BAD_PIPE: - *ux_signal = SIGPIPE; - break; - case EXC_UNIX_ABORT: - *ux_signal = SIGABRT; - break; - case EXC_SOFT_SIGNAL: - *ux_signal = SIGKILL; - break; - } - break; + proc_rele(p); - case EXC_BREAKPOINT: - *ux_signal = SIGTRAP; - break; - } + return KERN_SUCCESS; }