Ulrich Drepper | e1812e1 | 2006-07-12 07:46:03 +0000 | [diff] [blame] | 1 | /* Find debugging and symbol information for a module in libdwfl. |
Roland McGrath | 243fa26 | 2009-04-08 17:05:43 -0700 | [diff] [blame] | 2 | Copyright (C) 2006,2007,2009 Red Hat, Inc. |
Ulrich Drepper | e1812e1 | 2006-07-12 07:46:03 +0000 | [diff] [blame] | 3 | This file is part of Red Hat elfutils. |
| 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 | In addition, as a special exception, Red Hat, Inc. gives You the |
| 19 | additional right to link the code of Red Hat elfutils with code licensed |
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| 25 | those well defined interfaces identified in the file named EXCEPTION |
| 26 | found in the source code files (the "Approved Interfaces"). The files |
| 27 | of Non-GPL Code may instantiate templates or use macros or inline |
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| 40 | this file solely under the GPL without exception. |
| 41 | |
| 42 | Red Hat elfutils is an included package of the Open Invention Network. |
| 43 | An included package of the Open Invention Network is a package for which |
| 44 | Open Invention Network licensees cross-license their patents. No patent |
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| 48 | <http://www.openinventionnetwork.com>. */ |
| 49 | |
| 50 | #include "libdwflP.h" |
| 51 | |
| 52 | const char * |
| 53 | dwfl_module_getsym (Dwfl_Module *mod, int ndx, |
| 54 | GElf_Sym *sym, GElf_Word *shndxp) |
| 55 | { |
| 56 | if (unlikely (mod == NULL)) |
| 57 | return NULL; |
| 58 | |
| 59 | if (unlikely (mod->symdata == NULL)) |
| 60 | { |
| 61 | int result = INTUSE(dwfl_module_getsymtab) (mod); |
| 62 | if (result < 0) |
| 63 | return NULL; |
| 64 | } |
| 65 | |
| 66 | GElf_Word shndx; |
| 67 | sym = gelf_getsymshndx (mod->symdata, mod->symxndxdata, ndx, sym, &shndx); |
| 68 | if (unlikely (sym == NULL)) |
| 69 | { |
| 70 | __libdwfl_seterrno (DWFL_E_LIBELF); |
| 71 | return NULL; |
| 72 | } |
| 73 | |
| 74 | if (sym->st_shndx != SHN_XINDEX) |
| 75 | shndx = sym->st_shndx; |
| 76 | |
Roland McGrath | 19a8e4d | 2009-04-21 15:44:07 -0700 | [diff] [blame] | 77 | /* Figure out whether this symbol points into an SHF_ALLOC section. */ |
| 78 | bool alloc = true; |
| 79 | if ((shndxp != NULL || mod->e_type != ET_REL) |
| 80 | && (sym->st_shndx == SHN_XINDEX |
| 81 | || (sym->st_shndx < SHN_LORESERVE && sym->st_shndx != SHN_UNDEF))) |
Roland McGrath | 68f29f9 | 2009-04-08 17:52:33 -0700 | [diff] [blame] | 82 | { |
Roland McGrath | 19a8e4d | 2009-04-21 15:44:07 -0700 | [diff] [blame] | 83 | GElf_Shdr shdr_mem; |
| 84 | GElf_Shdr *shdr = gelf_getshdr (elf_getscn (mod->symfile->elf, shndx), |
| 85 | &shdr_mem); |
| 86 | alloc = unlikely (shdr == NULL) || (shdr->sh_flags & SHF_ALLOC); |
Roland McGrath | 68f29f9 | 2009-04-08 17:52:33 -0700 | [diff] [blame] | 87 | } |
Ulrich Drepper | e1812e1 | 2006-07-12 07:46:03 +0000 | [diff] [blame] | 88 | |
Roland McGrath | 19a8e4d | 2009-04-21 15:44:07 -0700 | [diff] [blame] | 89 | if (shndxp != NULL) |
| 90 | /* Yield -1 in case of a non-SHF_ALLOC section. */ |
| 91 | *shndxp = alloc ? shndx : (GElf_Word) -1; |
| 92 | |
Roland McGrath | 243fa26 | 2009-04-08 17:05:43 -0700 | [diff] [blame] | 93 | switch (sym->st_shndx) |
Ulrich Drepper | e1812e1 | 2006-07-12 07:46:03 +0000 | [diff] [blame] | 94 | { |
Roland McGrath | 19a8e4d | 2009-04-21 15:44:07 -0700 | [diff] [blame] | 95 | case SHN_ABS: /* XXX sometimes should use bias?? */ |
Ulrich Drepper | e1812e1 | 2006-07-12 07:46:03 +0000 | [diff] [blame] | 96 | case SHN_UNDEF: |
| 97 | case SHN_COMMON: |
| 98 | break; |
| 99 | |
| 100 | default: |
Roland McGrath | e4c22ea | 2007-10-23 13:07:39 +0000 | [diff] [blame] | 101 | if (mod->e_type == ET_REL) |
Ulrich Drepper | e1812e1 | 2006-07-12 07:46:03 +0000 | [diff] [blame] | 102 | { |
| 103 | /* In an ET_REL file, the symbol table values are relative |
| 104 | to the section, not to the module's load base. */ |
Ulrich Drepper | b597dfa | 2007-10-16 05:21:27 +0000 | [diff] [blame] | 105 | size_t symshstrndx = SHN_UNDEF; |
| 106 | Dwfl_Error result = __libdwfl_relocate_value (mod, mod->symfile->elf, |
| 107 | &symshstrndx, |
| 108 | shndx, &sym->st_value); |
Ulrich Drepper | e1812e1 | 2006-07-12 07:46:03 +0000 | [diff] [blame] | 109 | if (unlikely (result != DWFL_E_NOERROR)) |
| 110 | { |
| 111 | __libdwfl_seterrno (result); |
| 112 | return NULL; |
| 113 | } |
| 114 | } |
Roland McGrath | 19a8e4d | 2009-04-21 15:44:07 -0700 | [diff] [blame] | 115 | else if (alloc) |
Roland McGrath | 785dbb1 | 2009-04-08 17:15:01 -0700 | [diff] [blame] | 116 | /* Apply the bias to the symbol value. */ |
| 117 | sym->st_value += mod->symfile->bias; |
Ulrich Drepper | e1812e1 | 2006-07-12 07:46:03 +0000 | [diff] [blame] | 118 | break; |
| 119 | } |
| 120 | |
| 121 | if (unlikely (sym->st_name >= mod->symstrdata->d_size)) |
| 122 | { |
| 123 | __libdwfl_seterrno (DWFL_E_BADSTROFF); |
| 124 | return NULL; |
| 125 | } |
| 126 | return (const char *) mod->symstrdata->d_buf + sym->st_name; |
| 127 | } |
| 128 | INTDEF (dwfl_module_getsym) |