osfmk/kern/debug.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * @OSF_COPYRIGHT@
  25  */
  26 /*
  27  * Mach Operating System
  28  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  29  * All Rights Reserved.
  30  *
  31  * Permission to use, copy, modify and distribute this software and its
  32  * documentation is hereby granted, provided that both the copyright
  33  * notice and this permission notice appear in all copies of the
  34  * software, derivative works or modified versions, and any portions
  35  * thereof, and that both notices appear in supporting documentation.
  36  *
  37  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  38  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  39  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  40  *
  41  * Carnegie Mellon requests users of this software to return to
  42  *
  43  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  44  *  School of Computer Science
  45  *  Carnegie Mellon University
  46  *  Pittsburgh PA 15213-3890
  47  *
  48  * any improvements or extensions that they make and grant Carnegie Mellon
  49  * the rights to redistribute these changes.
  50  */
  51
  52 #include <mach_assert.h>
  53 #include <mach_kdb.h>
  54 #include <mach_kgdb.h>
  55 #include <mach_kdp.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 <vm/vm_kern.h>
  65 #include <vm/pmap.h>
  66 #include <stdarg.h>
  67
  68 #ifdef  __ppc__
  69 #include <ppc/Firmware.h>
  70 #include <ppc/low_trace.h>
  71 #endif
  72
  73 unsigned int    halt_in_debugger = 0;
  74 unsigned int    switch_debugger = 0;
  75 unsigned int    current_debugger = 0;
  76 unsigned int    active_debugger = 0;
  77 unsigned int    debug_mode=0;
  78 unsigned int    disableDebugOuput = TRUE;
  79 unsigned int    systemLogDiags = FALSE;
  80 unsigned int    logPanicDataToScreen = FALSE;
  81 unsigned int    panicDebugging = FALSE;
  82
  83 int mach_assert = 1;
  84
  85 const char              *panicstr = (char *) 0;
  86 decl_simple_lock_data(,panic_lock)
  87 int                     paniccpu;
  88 volatile int            panicwait;
  89 volatile unsigned int   nestedpanic= 0;
  90 unsigned int            panic_is_inited = 0;
  91 unsigned int            return_on_panic = 0;
  92 unsigned long           panic_caller;
  93
  94 char *debug_buf;
  95 ppnum_t debug_buf_page;
  96 char *debug_buf_ptr;
  97 unsigned int debug_buf_size = 0;
  98
  99 void
 100 Assert(
 101         const char      *file,
 102         int             line,
 103         const char      *expression)
 104 {
 105         if (!mach_assert) {
 106                 return;
 107         }
 108         panic("{%d} Assertion failed: file \"%s\", line %d: %s\n",
 109                cpu_number(), file, line, expression);
 110 }
 111
 112 /*
 113  *      Carefully use the panic_lock.  There's always a chance that
 114  *      somehow we'll call panic before getting to initialize the
 115  *      panic_lock -- in this case, we'll assume that the world is
 116  *      in uniprocessor mode and just avoid using the panic lock.
 117  */
 118 #define PANIC_LOCK()                                                    \
 119 MACRO_BEGIN                                                             \
 120         if (panic_is_inited)                                            \
 121                 simple_lock(&panic_lock);                               \
 122 MACRO_END
 123
 124 #define PANIC_UNLOCK()                                                  \
 125 MACRO_BEGIN                                                             \
 126         if (panic_is_inited)                                            \
 127                 simple_unlock(&panic_lock);                             \
 128 MACRO_END
 129
 130
 131 void
 132 panic_init(void)
 133 {
 134         simple_lock_init(&panic_lock, 0);
 135         panic_is_inited = 1;
 136         panic_caller = 0;
 137 }
 138
 139 void
 140 panic(const char *str, ...)
 141 {
 142         va_list listp;
 143         spl_t   s;
 144         thread_t thread;
 145         wait_queue_t wq;
 146
 147         s = splhigh();
 148         disable_preemption();
 149
 150 #ifdef  __ppc__
 151         lastTrace = LLTraceSet(0);              /* Disable low-level tracing */
 152 #endif
 153
 154         thread = current_thread();              /* Get failing thread */
 155         wq = thread->wait_queue;                /* Save the old value */
 156         thread->wait_queue = 0;                 /* Clear the wait so we do not get double panics when we try locks */
 157
 158         if( logPanicDataToScreen )
 159                 disableDebugOuput = FALSE;
 160
 161         debug_mode = TRUE;
 162
 163         /* panic_caller is initialized to 0.  If set, don't change it */
 164         if ( ! panic_caller )
 165                 panic_caller = (unsigned long) __builtin_return_address(0);
 166
 167 restart:
 168         PANIC_LOCK();
 169         if (panicstr) {
 170                 if (cpu_number() != paniccpu) {
 171                         PANIC_UNLOCK();
 172                         /*
 173                          * Wait until message has been printed to identify correct
 174                          * cpu that made the first panic.
 175                          */
 176                         while (panicwait)
 177                                 continue;
 178                         goto restart;
 179             } else {
 180                         nestedpanic +=1;
 181                         PANIC_UNLOCK();
 182                         Debugger("double panic");
 183                         printf("double panic:  We are hanging here...\n");
 184                         while(1);
 185                         /* NOTREACHED */
 186                 }
 187         }
 188         panicstr = str;
 189         paniccpu = cpu_number();
 190         panicwait = 1;
 191
 192         PANIC_UNLOCK();
 193         kdb_printf("panic(cpu %d caller 0x%08X): ", (unsigned) paniccpu, panic_caller);
 194         va_start(listp, str);
 195         _doprnt(str, &listp, consdebug_putc, 0);
 196         va_end(listp);
 197         kdb_printf("\n");
 198
 199         /*
 200          * Release panicwait indicator so that other cpus may call Debugger().
 201          */
 202         panicwait = 0;
 203         Debugger("panic");
 204         /*
 205          * Release panicstr so that we can handle normally other panics.
 206          */
 207         PANIC_LOCK();
 208         panicstr = (char *)0;
 209         PANIC_UNLOCK();
 210         thread->wait_queue = wq;        /* Restore the wait queue */
 211         if (return_on_panic) {
 212                 enable_preemption();
 213                 splx(s);
 214                 return;
 215         }
 216         kdb_printf("panic: We are hanging here...\n");
 217         while(1);
 218         /* NOTREACHED */
 219 }
 220
 221 void
 222 log(int level, char *fmt, ...)
 223 {
 224         va_list listp;
 225
 226 #ifdef lint
 227         level++;
 228 #endif /* lint */
 229 #ifdef  MACH_BSD
 230         disable_preemption();
 231         va_start(listp, fmt);
 232         _doprnt(fmt, &listp, conslog_putc, 0);
 233         va_end(listp);
 234         enable_preemption();
 235 #endif
 236 }
 237
 238 void
 239 debug_log_init(void)
 240 {
 241         if (debug_buf_size != 0)
 242                 return;
 243         if (kmem_alloc(kernel_map, (vm_offset_t *) &debug_buf, PAGE_SIZE) != KERN_SUCCESS)
 244                 panic("cannot allocate debug_buf \n");
 245         debug_buf_ptr = debug_buf;
 246         debug_buf_size = PAGE_SIZE;
 247         debug_buf_page = pmap_find_phys(kernel_pmap, (addr64_t)(uintptr_t)debug_buf_ptr);
 248 }
 249
 250 void
 251 debug_putc(char c)
 252 {
 253         if ((debug_buf_size != 0) && ((debug_buf_ptr-debug_buf) < debug_buf_size)) {
 254                 *debug_buf_ptr=c;
 255                 debug_buf_ptr++;
 256         }
 257 }