stacktrace.c

   1 #include <sys/types.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5
   6 typedef struct {
   7   char *name;
   8   void *addr;
   9   char type;
  10   size_t size;
  11 } symbol_t;
  12
  13 static char *get_debug_data() {
  14   size_t size = 0;
  15   char *buf = NULL;
  16
  17   while (!feof(stdin)) {
  18     buf = realloc(buf,size+BUFSIZ);
  19     size += fread(buf+size,1,BUFSIZ,stdin);
  20   }
  21
  22   return buf;
  23 }
  24
  25 static char *dd_get_proc(char *debug) {
  26   char *line = strstr(debug,"Process: #");
  27   if (line!=NULL) {
  28     char *space = strchr(line+10,' ');
  29     if (space!=NULL) {
  30       char *newline = strchr(space,'\n');
  31       if (newline!=NULL) {
  32         static char name[256];
  33         space++;
  34         memcpy(name,space,newline-space);
  35         name[newline-space] = 0;
  36         return name;
  37       }
  38     }
  39   }
  40   return NULL;
  41 }
  42
  43 static void *dd_get_eip(char *debug) {
  44   char *pos = strstr(debug,"EIP: ");
  45   if (pos!=NULL) {
  46     return (void*)strtoul(pos+5,NULL,16);
  47   }
  48   return NULL;
  49 }
  50
  51 static symbol_t *get_symbols(char *name) {
  52   char *cmd;
  53   symbol_t *symbols = NULL;
  54
  55   asprintf(&cmd,"nm -pP --defined-only files/bin/%s",name);
  56   FILE *nm = popen(cmd,"r");
  57   free(cmd);
  58   if (nm!=NULL) {
  59     size_t i;
  60     void *addr;
  61     char type;
  62     char name[512];
  63     size_t size;
  64
  65     for (i=0;fscanf(nm,"%s %c %x %x",name,&type,&addr,&size)>0;i++) {
  66       symbols = realloc(symbols,(i+1)*sizeof(symbol_t));
  67       symbols[i].addr = addr;
  68       symbols[i].name = strdup(name);
  69       symbols[i].type = type;
  70       symbols[i].size = size;
  71       addr = 0;
  72       type = 0;
  73       name[0] = 0;
  74       size = 0;
  75     }
  76     symbols = realloc(symbols,(i+1)*sizeof(symbol_t));
  77     memset(symbols+i,0,sizeof(symbol_t));
  78     pclose(nm);
  79     return symbols;
  80   }
  81   return NULL;
  82 }
  83
  84 static symbol_t *match_symbol(symbol_t *symbols,void *addr) {
  85   void *max = 0;
  86   symbol_t *best = NULL;
  87   size_t i;
  88
  89   for (i=0;symbols[i].type!=0;i++) {
  90     if (addr>symbols[i].addr && symbols[i].addr>max && (symbols[i].type=='t' || symbols[i].type=='T')) {
  91       max = symbols[i].addr;
  92       best = symbols+i;
  93     }
  94   }
  95   return best;
  96 }
  97
  98 static void match_stack(char *debug,symbol_t *symbols) {
  99   size_t i;
 100   char *stack = strstr(debug,"Stack:\n");
 101   if (stack!=NULL) {
 102     char *line = stack+6;
 103
 104     do {
 105       void *esp;
 106       void *addr;
 107
 108       line++; // skip \n
 109       sscanf(line,"0x%x: 0x%x",&esp,&addr);
 110
 111       symbol_t *symbol = match_symbol(symbols,addr);
 112       if (symbol!=NULL) {
 113         printf("0x%08x: 0x%08x %s+0x%x (%c,%d)\n",esp,addr,symbol->name,addr-symbol->addr,symbol->type,symbol->size);
 114       }
 115       else printf("0x%08x: 0x%08x\n",esp,addr);
 116
 117     } while ((line = strchr(line,'\n'))!=NULL);
 118   }
 119 }
 120
 121 static void match_eip(symbol_t *symbols,void *eip) {
 122   symbol_t *symbol = match_symbol(symbols,eip);
 123   if (symbol!=NULL) {
 124     printf("(EIP)       0x%08x %s+0x%x (%c,%d)\n",eip,symbol->name,eip-symbol->addr,symbol->type,symbol->size);
 125   }
 126   else printf("(EIP)       0x%08x\n",eip);
 127 }
 128
 129 int main(int argc,char *argv[]) {
 130   size_t i;
 131   char *debug = get_debug_data();
 132   if (debug==NULL) return 1;
 133
 134   char *proc_name = dd_get_proc(debug);
 135   if (proc_name==NULL) return 1;
 136   printf("|======{%s}======[Stacktrace]======|\n",proc_name);
 137
 138   symbol_t *symbols = get_symbols(proc_name);
 139   if (symbols==NULL) return 1;
 140
 141   void *eip = dd_get_eip(debug);
 142   if (eip!=NULL) match_eip(symbols,eip);
 143
 144   match_stack(debug,symbols);
 145
 146   free(debug);
 147   for (i=0;symbols[i].type!=0;i++) free(symbols[i].name);
 148   free(symbols);
 149
 150   return 0;
 151 }