mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-21 20:40:05 +00:00
b413280cfb
We can't relocate entries in dynamic section if it is readonly: 1. Add a l_ld_readonly field to struct link_map to indicate if dynamic section is readonly and set it based on p_flags of PT_DYNAMIC segment. 2. Replace DL_RO_DYN_SECTION with dl_relocate_ld to decide if dynamic section should be relocated. 3. Remove DL_RO_DYN_TEMP_CNT. 4. Don't use a static dynamic section to make readonly dynamic section in vDSO writable. 5. Remove the temp argument from elf_get_dynamic_info. This fixes BZ #28340. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
81 lines
2.7 KiB
C
81 lines
2.7 KiB
C
/* Support for relocating static PIE.
|
|
Copyright (C) 2017-2021 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#if ENABLE_STATIC_PIE
|
|
/* Mark symbols hidden in static PIE for early self relocation to work. */
|
|
# pragma GCC visibility push(hidden)
|
|
#include <unistd.h>
|
|
#include <ldsodefs.h>
|
|
#include "dynamic-link.h"
|
|
|
|
/* Relocate static executable with PIE. */
|
|
|
|
void
|
|
_dl_relocate_static_pie (void)
|
|
{
|
|
struct link_map *main_map = _dl_get_dl_main_map ();
|
|
|
|
# define STATIC_PIE_BOOTSTRAP
|
|
# define BOOTSTRAP_MAP (main_map)
|
|
# define RESOLVE_MAP(sym, version, flags) BOOTSTRAP_MAP
|
|
# include "dynamic-link.h"
|
|
|
|
/* Figure out the run-time load address of static PIE. */
|
|
main_map->l_addr = elf_machine_load_address ();
|
|
|
|
/* Read our own dynamic section and fill in the info array. */
|
|
main_map->l_ld = ((void *) main_map->l_addr + elf_machine_dynamic ());
|
|
|
|
const ElfW(Phdr) *ph, *phdr = GL(dl_phdr);
|
|
size_t phnum = GL(dl_phnum);
|
|
for (ph = phdr; ph < &phdr[phnum]; ++ph)
|
|
if (ph->p_type == PT_DYNAMIC)
|
|
{
|
|
main_map->l_ld_readonly = (ph->p_flags & PF_W) == 0;
|
|
break;
|
|
}
|
|
|
|
elf_get_dynamic_info (main_map);
|
|
|
|
# ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
|
|
ELF_MACHINE_BEFORE_RTLD_RELOC (main_map->l_info);
|
|
# endif
|
|
|
|
/* Relocate ourselves so we can do normal function calls and
|
|
data access using the global offset table. */
|
|
ELF_DYNAMIC_RELOCATE (main_map, 0, 0, 0);
|
|
main_map->l_relocated = 1;
|
|
|
|
/* Initialize _r_debug_extended. */
|
|
struct r_debug *r = _dl_debug_initialize (0, LM_ID_BASE);
|
|
r->r_state = RT_CONSISTENT;
|
|
|
|
/* Set up debugging before the debugger is notified for the first
|
|
time. */
|
|
# ifdef ELF_MACHINE_DEBUG_SETUP
|
|
/* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
|
|
ELF_MACHINE_DEBUG_SETUP (main_map, r);
|
|
# else
|
|
if (main_map->l_info[DT_DEBUG] != NULL)
|
|
/* There is a DT_DEBUG entry in the dynamic section. Fill it in
|
|
with the run-time address of the r_debug structure */
|
|
main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
|
|
# endif
|
|
}
|
|
#endif
|