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
  30 #ifndef __i386__
  31
  32 /* KLUDGE: Sigh ... I know what the call frame looks like and it had
  33  * better not change. */
  34
  35 struct call_frame {
  36 #ifndef alpha
  37         struct call_frame *old_cont;
  38 #else
  39         u32 old_cont;
  40 #endif
  41         lispobj saved_lra;
  42         lispobj code;
  43         lispobj other_state[5];
  44 };
  45
  46 struct call_info {
  47 #ifndef alpha
  48     struct call_frame *frame;
  49 #else
  50     u32 frame;
  51 #endif
  52     int interrupted;
  53 #ifndef alpha
  54     struct code *code;
  55 #else
  56     u32 code;
  57 #endif
  58     lispobj lra;
  59     int pc; /* Note: this is the trace file offset, not the actual pc. */
  60 };
  61
  62 #define HEADER_LENGTH(header) ((header)>>8)
  63
  64 static int previous_info(struct call_info *info);
  65
  66 static struct code *
  67 code_pointer(lispobj object)
  68 {
  69     lispobj *headerp, header;
  70     int type, len;
  71
  72     headerp = (lispobj *) native_pointer(object);
  73     header = *headerp;
  74     type = widetag_of(header);
  75
  76     switch (type) {
  77         case CODE_HEADER_WIDETAG:
  78             break;
  79         case RETURN_PC_HEADER_WIDETAG:
  80         case SIMPLE_FUN_HEADER_WIDETAG:
  81         case CLOSURE_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     return (((char *) CONTROL_STACK_START <= (char *) pointer) &&
  99             ((char *) pointer < (char *) current_control_stack_pointer));
 100 }
 101
 102 static void
 103 call_info_from_lisp_state(struct call_info *info)
 104 {
 105     info->frame = (struct call_frame *)current_control_frame_pointer;
 106     info->interrupted = 0;
 107     info->code = NULL;
 108     info->lra = 0;
 109     info->pc = 0;
 110
 111     previous_info(info);
 112 }
 113
 114 static void
 115 call_info_from_context(struct call_info *info, os_context_t *context)
 116 {
 117     unsigned long pc;
 118
 119     info->interrupted = 1;
 120     if (lowtag_of(*os_context_register_addr(context, reg_CODE))
 121         == FUN_POINTER_LOWTAG) {
 122         /* We tried to call a function, but crapped out before $CODE could
 123          * be fixed up. Probably an undefined function. */
 124         info->frame =
 125             (struct call_frame *)(*os_context_register_addr(context,
 126                                                             reg_OCFP));
 127         info->lra = (lispobj)(*os_context_register_addr(context, reg_LRA));
 128         info->code = code_pointer(info->lra);
 129         pc = (unsigned long)native_pointer(info->lra);
 130     }
 131     else {
 132         info->frame =
 133             (struct call_frame *)(*os_context_register_addr(context, reg_CFP));
 134         info->code =
 135             code_pointer(*os_context_register_addr(context, reg_CODE));
 136         info->lra = NIL;
 137         pc = *os_context_pc_addr(context);
 138     }
 139     if (info->code != NULL)
 140         info->pc = pc - (unsigned long) info->code -
 141 #ifndef alpha
 142             (HEADER_LENGTH(info->code->header) * sizeof(lispobj));
 143 #else
 144             (HEADER_LENGTH(((struct code *)info->code)->header) * sizeof(lispobj));
 145 #endif
 146     else
 147         info->pc = 0;
 148 }
 149
 150 static int
 151 previous_info(struct call_info *info)
 152 {
 153     struct call_frame *this_frame;
 154     struct thread *thread=arch_os_get_current_thread();
 155     int free;
 156
 157     if (!cs_valid_pointer_p(info->frame)) {
 158         printf("Bogus callee value (0x%08x).\n", (unsigned long)info->frame);
 159         return 0;
 160     }
 161
 162     this_frame = info->frame;
 163     info->lra = this_frame->saved_lra;
 164     info->frame = this_frame->old_cont;
 165     info->interrupted = 0;
 166
 167     if (info->frame == NULL || info->frame == this_frame)
 168         return 0;
 169
 170     if (info->lra == NIL) {
 171         /* We were interrupted. Find the correct signal context. */
 172         free = SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)>>2;
 173         while (free-- > 0) {
 174             os_context_t *context =
 175                 thread->interrupt_contexts[free];
 176             if ((struct call_frame *)(*os_context_register_addr(context,
 177                                                                 reg_CFP))
 178                 == info->frame) {
 179                 call_info_from_context(info, context);
 180                 break;
 181             }
 182         }
 183     }
 184     else {
 185         info->code = code_pointer(info->lra);
 186         if (info->code != NULL)
 187             info->pc = (unsigned long)native_pointer(info->lra) -
 188                 (unsigned long)info->code -
 189 #ifndef alpha
 190                 (HEADER_LENGTH(info->code->header) * sizeof(lispobj));
 191 #else
 192                 (HEADER_LENGTH(((struct code *)info->code)->header) * sizeof(lispobj));
 193 #endif
 194         else
 195             info->pc = 0;
 196     }
 197
 198     return 1;
 199 }
 200
 201 void
 202 backtrace(int nframes)
 203 {
 204     struct call_info info;
 205
 206     call_info_from_lisp_state(&info);
 207
 208     do {
 209         printf("<Frame 0x%08x%s, ", (unsigned long) info.frame,
 210                 info.interrupted ? " [interrupted]" : "");
 211
 212         if (info.code != (struct code *) 0) {
 213             lispobj function;
 214
 215             printf("CODE: 0x%08X, ", (unsigned long) info.code | OTHER_POINTER_LOWTAG);
 216
 217 #ifndef alpha
 218             function = info.code->entry_points;
 219 #else
 220             function = ((struct code *)info.code)->entry_points;
 221 #endif
 222             while (function != NIL) {
 223                 struct simple_fun *header;
 224                 lispobj name;
 225
 226                 header = (struct simple_fun *) native_pointer(function);
 227                 name = header->name;
 228
 229                 if (lowtag_of(name) == OTHER_POINTER_LOWTAG) {
 230                     lispobj *object;
 231
 232                     object = (lispobj *) native_pointer(name);
 233
 234                     if (widetag_of(*object) == SYMBOL_HEADER_WIDETAG) {
 235                         struct symbol *symbol;
 236
 237                         symbol = (struct symbol *) object;
 238                         object = (lispobj *) native_pointer(symbol->name);
 239                     }
 240                     if (widetag_of(*object) == SIMPLE_STRING_WIDETAG) {
 241                         struct vector *string;
 242
 243                         string = (struct vector *) object;
 244                         printf("%s, ", (char *) string->data);
 245                     } else
 246                         printf("(Not simple string??\?), ");
 247                 } else
 248                     printf("(Not other pointer??\?), ");
 249
 250
 251                 function = header->next;
 252             }
 253         }
 254         else
 255             printf("CODE: ???, ");
 256
 257         if (info.lra != NIL)
 258             printf("LRA: 0x%08x, ", (unsigned long)info.lra);
 259         else
 260             printf("<no LRA>, ");
 261
 262         if (info.pc)
 263             printf("PC: 0x%x>\n", info.pc);
 264         else
 265             printf("PC: ??\?>\n");
 266
 267     } while (--nframes > 0 && previous_info(&info));
 268 }
 269
 270 #else
 271
 272 void
 273 backtrace(int nframes)
 274 {
 275     printf("Can't backtrace on this hardware platform.\n");
 276 }
 277
 278 #endif