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1 /* Return program header table entry.
2    Copyright (C) 1998-2010 Red Hat, Inc.
3    This file is part of Red Hat elfutils.
4    Written by Ulrich Drepper <drepper@redhat.com>, 1998.
5 
6    Red Hat elfutils is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by the
8    Free Software Foundation; version 2 of the License.
9 
10    Red Hat elfutils is distributed in the hope that it will be useful, but
11    WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    General Public License for more details.
14 
15    You should have received a copy of the GNU General Public License along
16    with Red Hat elfutils; if not, write to the Free Software Foundation,
17    Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
18 
19    In addition, as a special exception, Red Hat, Inc. gives You the
20    additional right to link the code of Red Hat elfutils with code licensed
21    under any Open Source Initiative certified open source license
22    (http://www.opensource.org/licenses/index.php) which requires the
23    distribution of source code with any binary distribution and to
24    distribute linked combinations of the two.  Non-GPL Code permitted under
25    this exception must only link to the code of Red Hat elfutils through
26    those well defined interfaces identified in the file named EXCEPTION
27    found in the source code files (the "Approved Interfaces").  The files
28    of Non-GPL Code may instantiate templates or use macros or inline
29    functions from the Approved Interfaces without causing the resulting
30    work to be covered by the GNU General Public License.  Only Red Hat,
31    Inc. may make changes or additions to the list of Approved Interfaces.
32    Red Hat's grant of this exception is conditioned upon your not adding
33    any new exceptions.  If you wish to add a new Approved Interface or
34    exception, please contact Red Hat.  You must obey the GNU General Public
35    License in all respects for all of the Red Hat elfutils code and other
36    code used in conjunction with Red Hat elfutils except the Non-GPL Code
37    covered by this exception.  If you modify this file, you may extend this
38    exception to your version of the file, but you are not obligated to do
39    so.  If you do not wish to provide this exception without modification,
40    you must delete this exception statement from your version and license
41    this file solely under the GPL without exception.
42 
43    Red Hat elfutils is an included package of the Open Invention Network.
44    An included package of the Open Invention Network is a package for which
45    Open Invention Network licensees cross-license their patents.  No patent
46    license is granted, either expressly or impliedly, by designation as an
47    included package.  Should you wish to participate in the Open Invention
48    Network licensing program, please visit www.openinventionnetwork.com
49    <http://www.openinventionnetwork.com>.  */
50 
51 #ifdef HAVE_CONFIG_H
52 # include <config.h>
53 #endif
54 
55 #include <gelf.h>
56 #include <string.h>
57 #include <stdbool.h>
58 
59 #include "libelfP.h"
60 
61 
62 GElf_Phdr *
gelf_getphdr(elf,ndx,dst)63 gelf_getphdr (elf, ndx, dst)
64      Elf *elf;
65      int ndx;
66      GElf_Phdr *dst;
67 {
68   GElf_Phdr *result = NULL;
69 
70   if (elf == NULL)
71     return NULL;
72 
73   if (unlikely (elf->kind != ELF_K_ELF))
74     {
75       __libelf_seterrno (ELF_E_INVALID_HANDLE);
76       return NULL;
77     }
78 
79   if (dst == NULL)
80     {
81       __libelf_seterrno (ELF_E_INVALID_OPERAND);
82       return NULL;
83     }
84 
85   rwlock_rdlock (elf->lock);
86 
87   if (elf->class == ELFCLASS32)
88     {
89       /* Copy the elements one-by-one.  */
90       Elf32_Phdr *phdr = elf->state.elf32.phdr;
91 
92       if (phdr == NULL)
93 	{
94 	  rwlock_unlock (elf->lock);
95 	  phdr = INTUSE(elf32_getphdr) (elf);
96 	  if (phdr == NULL)
97 	    /* The error number is already set.  */
98 	    return NULL;
99 	  rwlock_rdlock (elf->lock);
100 	}
101 
102       /* Test whether the index is ok.  */
103       size_t phnum;
104       if (ndx >= elf->state.elf32.ehdr->e_phnum
105 	  && (elf->state.elf32.ehdr->e_phnum != PN_XNUM
106 	      || __elf_getphdrnum_rdlock (elf, &phnum) != 0
107 	      || (size_t) ndx >= phnum))
108 	{
109 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
110 	  goto out;
111 	}
112 
113       /* We know the result now.  */
114       result = dst;
115 
116       /* Now correct the pointer to point to the correct element.  */
117       phdr += ndx;
118 
119 #define COPY(Name) result->Name = phdr->Name
120       COPY (p_type);
121       COPY (p_offset);
122       COPY (p_vaddr);
123       COPY (p_paddr);
124       COPY (p_filesz);
125       COPY (p_memsz);
126       COPY (p_flags);
127       COPY (p_align);
128     }
129   else
130     {
131       /* Copy the elements one-by-one.  */
132       Elf64_Phdr *phdr = elf->state.elf64.phdr;
133 
134       if (phdr == NULL)
135 	{
136 	  rwlock_unlock (elf->lock);
137 	  phdr = INTUSE(elf64_getphdr) (elf);
138 	  if (phdr == NULL)
139 	    /* The error number is already set.  */
140 	    return NULL;
141 	  rwlock_rdlock (elf->lock);
142 	}
143 
144       /* Test whether the index is ok.  */
145       size_t phnum;
146       if (ndx >= elf->state.elf64.ehdr->e_phnum
147 	  && (elf->state.elf64.ehdr->e_phnum != PN_XNUM
148 	      || __elf_getphdrnum_rdlock (elf, &phnum) != 0
149 	      || (size_t) ndx >= phnum))
150 	{
151 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
152 	  goto out;
153 	}
154 
155       /* We only have to copy the data.  */
156       result = memcpy (dst, phdr + ndx, sizeof (GElf_Phdr));
157     }
158 
159  out:
160   rwlock_unlock (elf->lock);
161 
162   return result;
163 }
164