src/runtime/backtrace.c

   1 /*
   2  * simple backtrace facility
   3  */
   4
   5 /*
   6  * This software is part of the SBCL system. See the README file for
   7  * more information.
   8  *
   9  * This software is derived from the CMU CL system, which was
  10  * written at Carnegie Mellon University and released into the
  11  * public domain. The software is in the public domain and is
  12  * provided with absolutely no warranty. See the COPYING and CREDITS
  13  * files for more information.
  14  */
  15
  16 #include <stdio.h>
  17 #include <signal.h>
  18 #include "runtime.h"
  19 #include "sbcl.h"
  20 #include "globals.h"
  21 #include "os.h"
  22 #include "interrupt.h"
  23 #include "lispregs.h"
  24 #ifdef LISP_FEATURE_GENCGC
  25 #include "gencgc-alloc-region.h"
  26 #endif
  27 #include "genesis/static-symbols.h"
  28 #include "genesis/primitive-objects.h"
  29 #include "thread.h"
  30
  31 #ifndef LISP_FEATURE_X86
  32
  33 /* KLUDGE: Sigh ... I know what the call frame looks like and it had
  34  * better not change. */
  35
  36 struct call_frame {
  37 #ifndef alpha
  38         struct call_frame *old_cont;
  39 #else
  40         u32 old_cont;
  41 #endif
  42         lispobj saved_lra;
  43         lispobj code;
  44         lispobj other_state[5];
  45 };
  46
  47 struct call_info {
  48 #ifndef alpha
  49     struct call_frame *frame;
  50 #else
  51     u32 frame;
  52 #endif
  53     int interrupted;
  54 #ifndef alpha
  55     struct code *code;
  56 #else
  57     u32 code;
  58 #endif
  59     lispobj lra;
  60     int pc; /* Note: this is the trace file offset, not the actual pc. */
  61 };
  62
  63 #define HEADER_LENGTH(header) ((header)>>8)
  64
  65 static int previous_info(struct call_info *info);
  66
  67 static struct code *
  68 code_pointer(lispobj object)
  69 {
  70     lispobj *headerp, header;
  71     int type, len;
  72
  73     headerp = (lispobj *) native_pointer(object);
  74     header = *headerp;
  75     type = widetag_of(header);
  76
  77     switch (type) {
  78         case CODE_HEADER_WIDETAG:
  79             break;
  80         case RETURN_PC_HEADER_WIDETAG:
  81         case SIMPLE_FUN_HEADER_WIDETAG:
  82             len = HEADER_LENGTH(header);
  83             if (len == 0)
  84                 headerp = NULL;
  85             else
  86                 headerp -= len;
  87             break;
  88         default:
  89             headerp = NULL;
  90     }
  91
  92     return (struct code *) headerp;
  93 }
  94
  95 static boolean
  96 cs_valid_pointer_p(struct call_frame *pointer)
  97 {
  98     struct thread *thread=arch_os_get_current_thread();
  99     return (((char *) thread->control_stack_start <= (char *) pointer) &&
 100             ((char *) pointer < (char *) current_control_stack_pointer));
 101 }
 102
 103 static void
 104 call_info_from_lisp_state(struct call_info *info)
 105 {
 106     info->frame = (struct call_frame *)current_control_frame_pointer;
 107     info->interrupted = 0;
 108     info->code = NULL;
 109     info->lra = 0;
 110     info->pc = 0;
 111
 112     previous_info(info);
 113 }
 114
 115 static void
 116 call_info_from_context(struct call_info *info, os_context_t *context)
 117 {
 118     unsigned long pc;
 119
 120     info->interrupted = 1;
 121     if (lowtag_of(*os_context_register_addr(context, reg_CODE))
 122         == FUN_POINTER_LOWTAG) {
 123         /* We tried to call a function, but crapped out before $CODE could
 124          * be fixed up. Probably an undefined function. */
 125         info->frame =
 126             (struct call_frame *)(*os_context_register_addr(context,
 127                                                             reg_OCFP));
 128         info->lra = (lispobj)(*os_context_register_addr(context, reg_LRA));
 129         info->code = code_pointer(info->lra);
 130         pc = (unsigned long)native_pointer(info->lra);
 131     }
 132     else {
 133         info->frame =
 134             (struct call_frame *)(*os_context_register_addr(context, reg_CFP));
 135         info->code =
 136             code_pointer(*os_context_register_addr(context, reg_CODE));
 137         info->lra = NIL;
 138         pc = *os_context_pc_addr(context);
 139     }
 140     if (info->code != NULL)
 141         info->pc = pc - (unsigned long) info->code -
 142 #ifndef alpha
 143             (HEADER_LENGTH(info->code->header) * sizeof(lispobj));
 144 #else
 145             (HEADER_LENGTH(((struct code *)info->code)->header) * sizeof(lispobj));
 146 #endif
 147     else
 148         info->pc = 0;
 149 }
 150
 151 static int
 152 previous_info(struct call_info *info)
 153 {
 154     struct call_frame *this_frame;
 155     struct thread *thread=arch_os_get_current_thread();
 156     int free;
 157
 158     if (!cs_valid_pointer_p(info->frame)) {
 159         printf("Bogus callee value (0x%08x).\n", (unsigned long)info->frame);
 160         return 0;
 161     }
 162
 163     this_frame = info->frame;
 164     info->lra = this_frame->saved_lra;
 165     info->frame = this_frame->old_cont;
 166     info->interrupted = 0;
 167
 168     if (info->frame == NULL || info->frame == this_frame)
 169         return 0;
 170
 171     if (info->lra == NIL) {
 172         /* We were interrupted. Find the correct signal context. */
 173         free = SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)>>2;
 174         while (free-- > 0) {
 175             os_context_t *context =
 176                 thread->interrupt_contexts[free];
 177             if ((struct call_frame *)(*os_context_register_addr(context,
 178                                                                 reg_CFP))
 179                 == info->frame) {
 180                 call_info_from_context(info, context);
 181                 break;
 182             }
 183         }
 184     }
 185     else {
 186         info->code = code_pointer(info->lra);
 187         if (info->code != NULL)
 188             info->pc = (unsigned long)native_pointer(info->lra) -
 189                 (unsigned long)info->code -
 190 #ifndef alpha
 191                 (HEADER_LENGTH(info->code->header) * sizeof(lispobj));
 192 #else
 193                 (HEADER_LENGTH(((struct code *)info->code)->header) * sizeof(lispobj));
 194 #endif
 195         else
 196             info->pc = 0;
 197     }
 198
 199     return 1;
 200 }
 201
 202 void
 203 backtrace(int nframes)
 204 {
 205     struct call_info info;
 206
 207     call_info_from_lisp_state(&info);
 208
 209     do {
 210         printf("<Frame 0x%08x%s, ", (unsigned long) info.frame,
 211                 info.interrupted ? " [interrupted]" : "");
 212
 213         if (info.code != (struct code *) 0) {
 214             lispobj function;
 215
 216             printf("CODE: 0x%08X, ", (unsigned long) info.code | OTHER_POINTER_LOWTAG);
 217
 218 #ifndef alpha
 219             function = info.code->entry_points;
 220 #else
 221             function = ((struct code *)info.code)->entry_points;
 222 #endif
 223             while (function != NIL) {
 224                 struct simple_fun *header;
 225                 lispobj name;
 226
 227                 header = (struct simple_fun *) native_pointer(function);
 228                 name = header->name;
 229
 230                 if (lowtag_of(name) == OTHER_POINTER_LOWTAG) {
 231                     lispobj *object;
 232
 233                     object = (lispobj *) native_pointer(name);
 234
 235                     if (widetag_of(*object) == SYMBOL_HEADER_WIDETAG) {
 236                         struct symbol *symbol;
 237
 238                         symbol = (struct symbol *) object;
 239                         object = (lispobj *) native_pointer(symbol->name);
 240                     }
 241                     if (widetag_of(*object) == SIMPLE_BASE_STRING_WIDETAG) {
 242                         struct vector *string;
 243
 244                         string = (struct vector *) object;
 245                         printf("%s, ", (char *) string->data);
 246                     } else
 247                         printf("(Not simple string??\?), ");
 248                 } else
 249                     printf("(Not other pointer??\?), ");
 250
 251
 252                 function = header->next;
 253             }
 254         }
 255         else
 256             printf("CODE: ???, ");
 257
 258         if (info.lra != NIL)
 259             printf("LRA: 0x%08x, ", (unsigned long)info.lra);
 260         else
 261             printf("<no LRA>, ");
 262
 263         if (info.pc)
 264             printf("PC: 0x%x>\n", info.pc);
 265         else
 266             printf("PC: ??\?>\n");
 267
 268     } while (--nframes > 0 && previous_info(&info));
 269 }
 270
 271 #else
 272
 273
 274
 275 void
 276 backtrace(int nframes)
 277 {
 278     printf("Can't backtrace on this hardware platform.\n");
 279 }
 280
 281 #endif