xnu-7195.101.1.tar.gz

[apple/xnu.git] / bsd / uxkern / ux_exception.c

diff --git a/bsd/uxkern/ux_exception.c b/bsd/uxkern/ux_exception.c
index f0fbf42e70950b7b9b1c299f4e1e2d06c87e92c3..1ef01a1d4d6b88f571e7e90479e3924c911fa1c6 100644 (file)
--- 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
  * 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,
  * 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.
  * 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.
  */
 
  * 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 <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/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;

 }
 }