1/* Support for relocating static PIE.
2 Copyright (C) 2017-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#if ENABLE_STATIC_PIE
20/* Mark symbols hidden in static PIE for early self relocation to work. */
21# pragma GCC visibility push(hidden)
22#include <assert.h>
23#include <unistd.h>
24#include <ldsodefs.h>
25
26#include <dl-machine.h>
27#include <dl-debug.h>
28
29#define RESOLVE_MAP(map, scope, sym, version, flags) map
30#include "dynamic-link.h"
31#include "get-dynamic-info.h"
32
33/* Relocate static executable with PIE. */
34
35void
36_dl_relocate_static_pie (void)
37{
38 struct link_map *main_map = _dl_get_dl_main_map ();
39
40 /* Figure out the run-time load address of static PIE. */
41 main_map->l_addr = elf_machine_load_address ();
42
43 /* Read our own dynamic section and fill in the info array. */
44 main_map->l_ld = ((void *) main_map->l_addr + elf_machine_dynamic ());
45
46 const ElfW(Phdr) *ph, *phdr = GL(dl_phdr);
47 size_t phnum = GL(dl_phnum);
48 for (ph = phdr; ph < &phdr[phnum]; ++ph)
49 if (ph->p_type == PT_DYNAMIC)
50 {
51 main_map->l_ld_readonly = (ph->p_flags & PF_W) == 0;
52 break;
53 }
54
55 elf_get_dynamic_info (main_map, false, true);
56
57# ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
58 ELF_MACHINE_BEFORE_RTLD_RELOC (main_map, main_map->l_info);
59# endif
60
61 /* Relocate ourselves so we can do normal function calls and
62 data access using the global offset table. */
63 ELF_DYNAMIC_RELOCATE (main_map, NULL, 0, 0, 0);
64 main_map->l_relocated = 1;
65
66 /* Initialize _r_debug_extended. */
67 struct r_debug *r = _dl_debug_initialize (0, LM_ID_BASE);
68 r->r_state = RT_CONSISTENT;
69
70 /* Set up debugging before the debugger is notified for the first
71 time. */
72 elf_setup_debug_entry (main_map, r);
73}
74#endif
75