tools/kvm/symbol.c

   1 #include "kvm/symbol.h"
   2
   3 #include "kvm/kvm.h"
   4
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <stdio.h>
   8 #include <bfd.h>
   9
  10 static bfd              *abfd;
  11
  12 void symbol__init(const char *vmlinux)
  13 {
  14         if (!vmlinux)
  15                 return;
  16
  17         bfd_init();
  18
  19         abfd            = bfd_openr(vmlinux, NULL);
  20 }
  21
  22 static asymbol *lookup(asymbol **symbols, int nr_symbols, const char *symbol_name)
  23 {
  24         int i;
  25
  26         for (i = 0; i < nr_symbols; i++) {
  27                 asymbol *symbol = symbols[i];
  28
  29                 if (!strcmp(bfd_asymbol_name(symbol), symbol_name))
  30                         return symbol;
  31         }
  32
  33         return NULL;
  34 }
  35
  36 char *symbol__lookup(struct kvm *kvm, unsigned long addr, char *sym, size_t size)
  37 {
  38         const char *filename;
  39         bfd_vma sym_offset;
  40         bfd_vma sym_start;
  41         asection *section;
  42         unsigned int line;
  43         const char *func;
  44         long symtab_size;
  45         asymbol *symbol;
  46         asymbol **syms;
  47         int nr_syms;
  48         char *s;
  49
  50         if (!abfd)
  51                 goto not_found;
  52
  53         if (!bfd_check_format(abfd, bfd_object))
  54                 goto not_found;
  55
  56         symtab_size     = bfd_get_symtab_upper_bound(abfd);
  57         if (!symtab_size)
  58                 goto not_found;
  59
  60         syms            = malloc(symtab_size);
  61         if (!syms)
  62                 goto not_found;
  63
  64         nr_syms         = bfd_canonicalize_symtab(abfd, syms);
  65
  66         section         = bfd_get_section_by_name(abfd, ".debug_aranges");
  67         if (!section)
  68                 goto not_found;
  69
  70         if (!bfd_find_nearest_line(abfd, section, NULL, addr, &filename, &func, &line))
  71                 goto not_found;
  72
  73         if (!func)
  74                 goto not_found;
  75
  76         symbol          = lookup(syms, nr_syms, func);
  77         if (!symbol)
  78                 goto not_found;
  79
  80         sym_start       = bfd_asymbol_value(symbol);
  81
  82         sym_offset      = addr - sym_start;
  83
  84         snprintf(sym, size, "%s+%llx (%s:%i)", func, (long long) sym_offset, filename, line);
  85
  86         sym[size - 1] = '\0';
  87
  88         free(syms);
  89
  90         return sym;
  91
  92 not_found:
  93         s = strncpy(sym, "<unknown>", size);
  94
  95         sym[size - 1] = '\0';
  96
  97         return s;
  98 }