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 __i386__
  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         case CLOSURE_FUN_HEADER_WIDETAG:
  83             len = HEADER_LENGTH(header);
  84             if (len == 0)
  85                 headerp = NULL;
  86             else
  87                 headerp -= len;
  88             break;
  89         default:
  90             headerp = NULL;
  91     }
  92
  93     return (struct code *) headerp;
  94 }
  95
  96 static boolean
  97 cs_valid_pointer_p(struct call_frame *pointer)
  98 {
  99     struct thread *thread=arch_os_get_current_thread();
 100     return (((char *) thread->control_stack_start <= (char *) pointer) &&
 101             ((char *) pointer < (char *) current_control_stack_pointer));
 102 }
 103
 104 static void
 105 call_info_from_lisp_state(struct call_info *info)
 106 {
 107     info->frame = (struct call_frame *)current_control_frame_pointer;
 108     info->interrupted = 0;
 109     info->code = NULL;
 110     info->lra = 0;
 111     info->pc = 0;
 112
 113     previous_info(info);
 114 }
 115
 116 static void
 117 call_info_from_context(struct call_info *info, os_context_t *context)
 118 {
 119     unsigned long pc;
 120
 121     info->interrupted = 1;
 122     if (lowtag_of(*os_context_register_addr(context, reg_CODE))
 123         == FUN_POINTER_LOWTAG) {
 124         /* We tried to call a function, but crapped out before $CODE could
 125          * be fixed up. Probably an undefined function. */
 126         info->frame =
 127             (struct call_frame *)(*os_context_register_addr(context,
 128                                                             reg_OCFP));
 129         info->lra = (lispobj)(*os_context_register_addr(context, reg_LRA));
 130         info->code = code_pointer(info->lra);
 131         pc = (unsigned long)native_pointer(info->lra);
 132     }
 133     else {
 134         info->frame =
 135             (struct call_frame *)(*os_context_register_addr(context, reg_CFP));
 136         info->code =
 137             code_pointer(*os_context_register_addr(context, reg_CODE));
 138         info->lra = NIL;
 139         pc = *os_context_pc_addr(context);
 140     }
 141     if (info->code != NULL)
 142         info->pc = pc - (unsigned long) info->code -
 143 #ifndef alpha
 144             (HEADER_LENGTH(info->code->header) * sizeof(lispobj));
 145 #else
 146             (HEADER_LENGTH(((struct code *)info->code)->header) * sizeof(lispobj));
 147 #endif
 148     else
 149         info->pc = 0;
 150 }
 151
 152 static int
 153 previous_info(struct call_info *info)
 154 {
 155     struct call_frame *this_frame;
 156     struct thread *thread=arch_os_get_current_thread();
 157     int free;
 158
 159     if (!cs_valid_pointer_p(info->frame)) {
 160         printf("Bogus callee value (0x%08x).\n", (unsigned long)info->frame);
 161         return 0;
 162     }
 163
 164     this_frame = info->frame;
 165     info->lra = this_frame->saved_lra;
 166     info->frame = this_frame->old_cont;
 167     info->interrupted = 0;
 168
 169     if (info->frame == NULL || info->frame == this_frame)
 170         return 0;
 171
 172     if (info->lra == NIL) {
 173         /* We were interrupted. Find the correct signal context. */
 174         free = SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)>>2;
 175         while (free-- > 0) {
 176             os_context_t *context =
 177                 thread->interrupt_contexts[free];
 178             if ((struct call_frame *)(*os_context_register_addr(context,
 179                                                                 reg_CFP))
 180                 == info->frame) {
 181                 call_info_from_context(info, context);
 182                 break;
 183             }
 184         }
 185     }
 186     else {
 187         info->code = code_pointer(info->lra);
 188         if (info->code != NULL)
 189             info->pc = (unsigned long)native_pointer(info->lra) -
 190                 (unsigned long)info->code -
 191 #ifndef alpha
 192                 (HEADER_LENGTH(info->code->header) * sizeof(lispobj));
 193 #else
 194                 (HEADER_LENGTH(((struct code *)info->code)->header) * sizeof(lispobj));
 195 #endif
 196         else
 197             info->pc = 0;
 198     }
 199
 200     return 1;
 201 }
 202
 203 void
 204 backtrace(int nframes)
 205 {
 206     struct call_info info;
 207
 208     call_info_from_lisp_state(&info);
 209
 210     do {
 211         printf("<Frame 0x%08x%s, ", (unsigned long) info.frame,
 212                 info.interrupted ? " [interrupted]" : "");
 213
 214         if (info.code != (struct code *) 0) {
 215             lispobj function;
 216
 217             printf("CODE: 0x%08X, ", (unsigned long) info.code | OTHER_POINTER_LOWTAG);
 218
 219 #ifndef alpha
 220             function = info.code->entry_points;
 221 #else
 222             function = ((struct code *)info.code)->entry_points;
 223 #endif
 224             while (function != NIL) {
 225                 struct simple_fun *header;
 226                 lispobj name;
 227
 228                 header = (struct simple_fun *) native_pointer(function);
 229                 name = header->name;
 230
 231                 if (lowtag_of(name) == OTHER_POINTER_LOWTAG) {
 232                     lispobj *object;
 233
 234                     object = (lispobj *) native_pointer(name);
 235
 236                     if (widetag_of(*object) == SYMBOL_HEADER_WIDETAG) {
 237                         struct symbol *symbol;
 238
 239                         symbol = (struct symbol *) object;
 240                         object = (lispobj *) native_pointer(symbol->name);
 241                     }
 242                     if (widetag_of(*object) == SIMPLE_STRING_WIDETAG) {
 243                         struct vector *string;
 244
 245                         string = (struct vector *) object;
 246                         printf("%s, ", (char *) string->data);
 247                     } else
 248                         printf("(Not simple string??\?), ");
 249                 } else
 250                     printf("(Not other pointer??\?), ");
 251
 252
 253                 function = header->next;
 254             }
 255         }
 256         else
 257             printf("CODE: ???, ");
 258
 259         if (info.lra != NIL)
 260             printf("LRA: 0x%08x, ", (unsigned long)info.lra);
 261         else
 262             printf("<no LRA>, ");
 263
 264         if (info.pc)
 265             printf("PC: 0x%x>\n", info.pc);
 266         else
 267             printf("PC: ??\?>\n");
 268
 269     } while (--nframes > 0 && previous_info(&info));
 270 }
 271
 272 #else
 273
 274 void
 275 backtrace(int nframes)
 276 {
 277     printf("Can't backtrace on this hardware platform.\n");
 278 }
 279
 280 #endif