osfmk/kern/debug.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50
  51 #include <mach_assert.h>
  52 #include <mach_kdb.h>
  53 #include <mach_kgdb.h>
  54 #include <mach_kdp.h>
  55 #include <cpus.h>
  56
  57 #include <kern/cpu_number.h>
  58 #include <kern/lock.h>
  59 #include <kern/spl.h>
  60 #include <kern/thread.h>
  61 #include <kern/assert.h>
  62 #include <kern/sched_prim.h>
  63 #include <kern/misc_protos.h>
  64 #include <stdarg.h>
  65
  66 unsigned int    halt_in_debugger = 0;
  67 unsigned int    switch_debugger = 0;
  68 unsigned int    current_debugger = 0;
  69 unsigned int    active_debugger = 0;
  70 unsigned int    debug_mode=0;
  71 unsigned int    disableDebugOuput = TRUE;
  72 unsigned int    systemLogDiags = FALSE;
  73
  74 int mach_assert = 1;
  75
  76 const char              *panicstr;
  77 decl_simple_lock_data(,panic_lock)
  78 int                     paniccpu;
  79 volatile int            panicwait;
  80 volatile int            nestedpanic= 0;
  81 unsigned int            panic_is_inited = 0;
  82 unsigned int            return_on_panic = 0;
  83 wait_queue_t            save_waits[NCPUS];
  84
  85 void
  86 Assert(
  87         const char      *file,
  88         int             line,
  89         const char      *expression)
  90 {
  91         if (!mach_assert) {
  92                 return;
  93         }
  94         panic("{%d} Assertion failed: file \"%s\", line %d: %s\n",
  95                cpu_number(), file, line, expression);
  96 }
  97
  98 /*
  99  *      Carefully use the panic_lock.  There's always a chance that
 100  *      somehow we'll call panic before getting to initialize the
 101  *      panic_lock -- in this case, we'll assume that the world is
 102  *      in uniprocessor mode and just avoid using the panic lock.
 103  */
 104 #define PANIC_LOCK()                                                    \
 105 MACRO_BEGIN                                                             \
 106         if (panic_is_inited)                                            \
 107                 simple_lock(&panic_lock);                               \
 108 MACRO_END
 109
 110 #define PANIC_UNLOCK()                                                  \
 111 MACRO_BEGIN                                                             \
 112         if (panic_is_inited)                                            \
 113                 simple_unlock(&panic_lock);                             \
 114 MACRO_END
 115
 116
 117 void
 118 panic_init(void)
 119 {
 120         simple_lock_init(&panic_lock, ETAP_NO_TRACE);
 121         panic_is_inited = 1;
 122 }
 123
 124 void
 125 panic(const char *str, ...)
 126 {
 127         va_list listp;
 128         spl_t   s;
 129         thread_t thread;
 130
 131         s = splhigh();
 132
 133         thread = current_thread();              /* Get failing thread */
 134         save_waits[cpu_number()] = thread->wait_queue;  /* Save the old value */
 135         thread->wait_queue = 0;                 /* Clear the wait so we do not get double panics when we try locks */
 136
 137         mp_disable_preemption();
 138         disableDebugOuput = FALSE;
 139         debug_mode = TRUE;
 140 restart:
 141         PANIC_LOCK();
 142         if (panicstr) {
 143                 if (cpu_number() != paniccpu) {
 144                         PANIC_UNLOCK();
 145                         /*
 146                          * Wait until message has been printed to identify correct
 147                          * cpu that made the first panic.
 148                          */
 149                         while (panicwait)
 150                                 continue;
 151                         goto restart;
 152             } else {
 153                         nestedpanic +=1;
 154                         PANIC_UNLOCK();
 155                         Debugger("double panic");
 156                         mp_enable_preemption();
 157                         splx(s);
 158                         printf("double panic:  We are hanging here...\n");
 159                         while(1);
 160                         /* NOTREACHED */
 161                 }
 162         }
 163         panicstr = str;
 164         paniccpu = cpu_number();
 165         panicwait = 1;
 166
 167         PANIC_UNLOCK();
 168         printf("panic(cpu %d): ", (unsigned) paniccpu);
 169         va_start(listp, str);
 170         _doprnt(str, &listp, cnputc, 0);
 171         va_end(listp);
 172         printf("\n");
 173
 174         /*
 175          * Release panicwait indicator so that other cpus may call Debugger().
 176          */
 177         panicwait = 0;
 178         Debugger("panic");
 179         /*
 180          * Release panicstr so that we can handle normally other panics.
 181          */
 182         PANIC_LOCK();
 183         panicstr = (char *)0;
 184         PANIC_UNLOCK();
 185         mp_enable_preemption();
 186         splx(s);
 187         thread->wait_queue = save_waits[cpu_number()];  /* Restore the wait queue */
 188         if (return_on_panic)
 189                 return;
 190         printf("panic: We are hanging here...\n");
 191         while(1);
 192         /* NOTREACHED */
 193 }
 194
 195 void
 196 log(int level, char *fmt, ...)
 197 {
 198         va_list listp;
 199         extern void conslog_putc(char);
 200
 201 #ifdef lint
 202         level++;
 203 #endif /* lint */
 204 #ifdef  MACH_BSD
 205         disable_preemption();
 206         va_start(listp, fmt);
 207         _doprnt(fmt, &listp, conslog_putc, 0);
 208         va_end(listp);
 209         enable_preemption();
 210 #endif
 211 }