1/* Copyright (C) 2005, 2007, 2008 Red Hat, Inc.
2   This file is part of Red Hat elfutils.
3   Written by Ulrich Drepper <drepper@redhat.com>, 2005.
4
5   Red Hat elfutils is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by the
7   Free Software Foundation; version 2 of the License.
8
9   Red Hat elfutils is distributed in the hope that it will be useful, but
10   WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   General Public License for more details.
13
14   You should have received a copy of the GNU General Public License along
15   with Red Hat elfutils; if not, write to the Free Software Foundation,
16   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
17
18   Red Hat elfutils is an included package of the Open Invention Network.
19   An included package of the Open Invention Network is a package for which
20   Open Invention Network licensees cross-license their patents.  No patent
21   license is granted, either expressly or impliedly, by designation as an
22   included package.  Should you wish to participate in the Open Invention
23   Network licensing program, please visit www.openinventionnetwork.com
24   <http://www.openinventionnetwork.com>.  */
25
26#ifdef HAVE_CONFIG_H
27# include <config.h>
28#endif
29
30#include <string.h>
31
32#include "libasmP.h"
33#include "../libebl/libeblP.h"
34
35
36struct symtoken
37{
38  DisasmCtx_t *ctx;
39  void *symcbarg;
40};
41
42
43static int
44default_elf_getsym (GElf_Addr addr, Elf32_Word scnndx, GElf_Addr value,
45		    char **buf, size_t *buflen, void *arg)
46{
47  struct symtoken *symtoken = (struct symtoken *) arg;
48
49  /* First try the user provided function.  */
50  if (symtoken->ctx->symcb != NULL)
51    {
52      int res = symtoken->ctx->symcb (addr, scnndx, value, buf, buflen,
53				      symtoken->symcbarg);
54      if (res >= 0)
55	return res;
56    }
57
58  // XXX Look up in ELF file.
59
60  return -1;
61}
62
63
64struct symaddrpair
65{
66  GElf_Addr addr;
67  const char *name;
68};
69
70
71static void
72read_symtab_exec (DisasmCtx_t *ctx)
73{
74  /* We simply use all we can get our hands on.  This will produce
75     some duplicate information but this is no problem, we simply
76     ignore the latter definitions.  */
77  Elf_Scn *scn= NULL;
78  while ((scn = elf_nextscn (ctx->elf, scn)) != NULL)
79    {
80      GElf_Shdr shdr_mem;
81      GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
82      Elf_Data *data;
83      if (shdr == NULL || shdr->sh_type != SHT_SYMTAB
84	  || (data = elf_getdata (scn, NULL)) == NULL)
85	continue;
86
87      int xndxscnidx = elf_scnshndx (scn);
88      Elf_Data *xndxdata = NULL;
89      if (xndxscnidx > 0)
90	xndxdata = elf_getdata (elf_getscn (ctx->elf, xndxscnidx), NULL);
91
92      /* Iterate over all symbols.  Add all defined symbols.  */
93      int nsyms = shdr->sh_size / shdr->sh_entsize;
94      for (int cnt = 1; cnt < nsyms; ++cnt)
95	{
96	  Elf32_Word xshndx;
97	  GElf_Sym sym_mem;
98	  GElf_Sym *sym = gelf_getsymshndx (data, xndxdata, cnt, &sym_mem,
99					    &xshndx);
100	  if (sym == NULL)
101	    continue;
102
103	  /* Undefined symbols are useless here.  */
104	  if (sym->st_shndx == SHN_UNDEF)
105	    continue;
106
107
108	}
109    }
110}
111
112
113static void
114read_symtab (DisasmCtx_t *ctx)
115{
116  /* Find the symbol table(s).  */
117  GElf_Ehdr ehdr_mem;
118  GElf_Ehdr *ehdr = gelf_getehdr (ctx->elf, &ehdr_mem);
119  if (ehdr == NULL)
120    return;
121
122  switch (ehdr->e_type)
123    {
124    case ET_EXEC:
125    case ET_DYN:
126      read_symtab_exec (ctx);
127      break;
128
129    case ET_REL:
130      // XXX  Handle
131      break;
132
133    default:
134      break;
135    }
136}
137
138
139static int
140null_elf_getsym (GElf_Addr addr __attribute__ ((unused)),
141		 Elf32_Word scnndx __attribute__ ((unused)),
142		 GElf_Addr value __attribute__ ((unused)),
143		 char **buf __attribute__ ((unused)),
144		 size_t *buflen __attribute__ ((unused)),
145		 void *arg __attribute__ ((unused)))
146{
147  return -1;
148}
149
150
151int
152disasm_cb (DisasmCtx_t *ctx, const uint8_t **startp, const uint8_t *end,
153	   GElf_Addr addr, const char *fmt, DisasmOutputCB_t outcb,
154	   void *outcbarg, void *symcbarg)
155{
156  struct symtoken symtoken;
157  DisasmGetSymCB_t getsym = ctx->symcb ?: null_elf_getsym;
158
159  if (ctx->elf != NULL)
160    {
161      /* Read all symbols of the ELF file and stuff them into a hash
162	 table.  The key is the address and the section index.  */
163      read_symtab (ctx);
164
165      symtoken.ctx = ctx;
166      symtoken.symcbarg = symcbarg;
167
168      symcbarg = &symtoken;
169
170      getsym = default_elf_getsym;
171    }
172
173  return ctx->ebl->disasm (startp, end, addr, fmt, outcb, getsym, outcbarg,
174			   symcbarg);
175}
176INTDEF (disasm_cb)
177