cp/nucleus/symtab.c

   1 /*
   2  * (C) Copyright 2007-2011  Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
   3  *
   4  * This file is released under the GPLv2.  See the COPYING file for more
   5  * details.
   6  */
   7
   8 #include <symtab.h>
   9
  10 Elf64_Ehdr *symtab;
  11
  12 static Elf64_Shdr *__get_section(int i)
  13 {
  14         return ((void*)symtab) + symtab->e_shoff + symtab->e_shentsize * i;
  15 }
  16
  17 static void *get_section(int type, int *entsize, int *size)
  18 {
  19         Elf64_Shdr *cur;
  20         int getstr = 0;
  21         int i;
  22
  23         /* we want the string table associated with the symbol table */
  24         if (type == SHT_STRTAB) {
  25                 getstr = 1;
  26                 type = SHT_SYMTAB;
  27         }
  28
  29         for(i=0; i<symtab->e_shnum; i++) {
  30                 cur = __get_section(i);
  31
  32                 if (cur->sh_type == type)
  33                         goto found;
  34         }
  35
  36         return NULL;
  37
  38 found:
  39
  40         if (getstr)
  41                 cur = __get_section(cur->sh_link);
  42
  43         *entsize = cur->sh_entsize;
  44         *size = cur->sh_size;
  45         return ((void*)symtab) + cur->sh_offset;
  46 }
  47
  48 void symtab_find_text_range(u64 *start, u64 *end)
  49 {
  50         u64 s, e;
  51         Elf64_Sym *cur, *tab;
  52         int entsize, size;
  53         int bind, type;
  54
  55         s = -1;
  56         e = 0;
  57
  58         tab = get_section(SHT_SYMTAB, &entsize, &size);
  59         if (!tab)
  60                 return;
  61
  62         cur=tab;
  63
  64         while(((void*)cur)-((void*)tab)<size) {
  65                 cur = ((void*)cur) + entsize;
  66
  67                 bind = cur->st_info >> 4;
  68                 type = cur->st_info & 0xf;
  69
  70                 if ((bind != STB_LOCAL) && (bind != STB_GLOBAL))
  71                         continue;
  72
  73                 if ((type != STT_OBJECT) && (type != STT_FUNC))
  74                         continue;
  75
  76                 if (s > cur->st_value)
  77                         s = cur->st_value;
  78                 if (e < (cur->st_value + cur->st_size))
  79                         e = cur->st_value + cur->st_size;
  80         }
  81
  82         *start = s;
  83         *end = e;
  84 }
  85
  86 char *symtab_lookup(u64 addr, char *buf, int buflen)
  87 {
  88         Elf64_Sym *cur, *tab;
  89         char *strtab;
  90         int entsize, size;
  91         int strsize, dummy;
  92         int bind, type;
  93
  94         tab = get_section(SHT_SYMTAB, &entsize, &size);
  95         if (!tab)
  96                 goto fail;
  97
  98         strtab = get_section(SHT_STRTAB, &dummy, &strsize);
  99         if (!strtab)
 100                 goto fail;
 101
 102         cur=tab;
 103
 104         while(((void*)cur)-((void*)tab)<size) {
 105                 cur = ((void*)cur) + entsize;
 106
 107                 bind = cur->st_info >> 4;
 108                 type = cur->st_info & 0xf;
 109
 110                 if ((bind != STB_LOCAL) && (bind != STB_GLOBAL))
 111                         continue;
 112
 113                 if ((type != STT_OBJECT) && (type != STT_FUNC))
 114                         continue;
 115
 116                 if (addr < cur->st_value)
 117                         continue;
 118                 if (addr >= (cur->st_value + cur->st_size))
 119                         continue;
 120
 121                 /* ok, found the symbol */
 122                 if (cur->st_name > strsize)
 123                         goto fail;
 124
 125                 snprintf(buf, buflen, "%s+%#llx",
 126                          strtab + cur->st_name, addr - cur->st_value);
 127                 return buf;
 128         }
 129
 130 fail:
 131         return "???";
 132 }