/*
- * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2017 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_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
* 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,
* 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_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 <sys/param.h>
#include <mach/boolean.h>
#include <mach/exception.h>
#include <mach/kern_return.h>
-#include <mach/message.h>
-#include <mach/port.h>
-#include <mach/mach_port.h>
-#include <mach/mig_errors.h>
-#include <mach/exc_server.h>
-#include <kern/task.h>
-#include <kern/thread.h>
-#include <kern/sched_prim.h>
-#include <kern/kalloc.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/systm.h>
-#include <sys/ux_exception.h>
-
-#include <vm/vm_protos.h> /* 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 <sys/vmparam.h> /* MAXSSIZ */
+#include <sys/ux_exception.h>
/*
- * 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;
}
projects / apple / xnu.git / blobdiff