mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 21:10:07 +00:00
331 lines
11 KiB
C
331 lines
11 KiB
C
/* Machine-dependent ELF dynamic relocation inline functions. ARC version.
|
|
Copyright (C) 2020-2023 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/>. */
|
|
|
|
#ifndef dl_machine_h
|
|
#define dl_machine_h
|
|
|
|
#define ELF_MACHINE_NAME "arc"
|
|
|
|
#include <entry.h>
|
|
|
|
#ifndef ENTRY_POINT
|
|
# error ENTRY_POINT needs to be defined for ARC
|
|
#endif
|
|
|
|
#include <string.h>
|
|
#include <link.h>
|
|
#include <dl-tls.h>
|
|
#include <dl-static-tls.h>
|
|
#include <dl-machine-rel.h>
|
|
|
|
/* Dynamic Linking ABI for ARCv2 ISA.
|
|
|
|
PLT
|
|
-------------------------------- <---- DT_PLTGOT
|
|
| ld r11, [pcl, off-to-GOT[1] | 0
|
|
| | 4
|
|
plt0 | ld r10, [pcl, off-to-GOT[2] | 8
|
|
| | 12
|
|
| j [r10] | 16
|
|
--------------------------------
|
|
| Base address of GOT | 20
|
|
--------------------------------
|
|
| ld r12, [pcl, off-to-GOT[3] | 24
|
|
plt1 | |
|
|
| j.d [r12] | 32
|
|
| mov r12, pcl | 36
|
|
--------------------------------
|
|
| | 40
|
|
~ ~
|
|
~ ~
|
|
| |
|
|
--------------------------------
|
|
|
|
.got
|
|
--------------
|
|
| [0] |
|
|
| ... | Runtime address for data symbols
|
|
| [n] |
|
|
--------------
|
|
|
|
.got.plt
|
|
--------------
|
|
| [0] | Build address of .dynamic
|
|
--------------
|
|
| [1] | Module info - setup by ld.so
|
|
--------------
|
|
| [2] | resolver entry point
|
|
--------------
|
|
| [3] |
|
|
| ... | Runtime address for function symbols
|
|
| [f] |
|
|
--------------
|
|
|
|
For ARCompact, the PLT is 12 bytes due to short instructions
|
|
|
|
--------------------------------
|
|
| ld r12, [pcl, off-to-GOT[3] | 24 (12 bytes each)
|
|
plt1 | |
|
|
| j_s.d [r12] | 32
|
|
| mov_s r12, pcl | 34
|
|
--------------------------------
|
|
| | 36 */
|
|
|
|
/* Return nonzero iff ELF header is compatible with the running host. */
|
|
static inline int
|
|
elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
|
|
{
|
|
return (ehdr->e_machine == EM_ARCV2 /* ARC HS. */
|
|
|| ehdr->e_machine == EM_ARC_COMPACT); /* ARC 700. */
|
|
}
|
|
|
|
/* Get build time address of .dynamic as setup in GOT[0]
|
|
This is called very early in _dl_start so it has not been relocated to
|
|
runtime value. */
|
|
static inline ElfW(Addr)
|
|
elf_machine_dynamic (void)
|
|
{
|
|
extern const ElfW(Addr) _GLOBAL_OFFSET_TABLE_[] attribute_hidden;
|
|
return _GLOBAL_OFFSET_TABLE_[0];
|
|
}
|
|
|
|
|
|
/* Return the run-time load address of the shared object. */
|
|
static inline ElfW(Addr)
|
|
elf_machine_load_address (void)
|
|
{
|
|
ElfW(Addr) build_addr, run_addr;
|
|
|
|
/* For build address, below generates
|
|
ld r0, [pcl, _GLOBAL_OFFSET_TABLE_@pcl]. */
|
|
build_addr = elf_machine_dynamic ();
|
|
__asm__ ("add %0, pcl, _DYNAMIC@pcl \n" : "=r" (run_addr));
|
|
|
|
return run_addr - build_addr;
|
|
}
|
|
|
|
/* Set up the loaded object described by L so its unrelocated PLT
|
|
entries will jump to the on-demand fixup code in dl-runtime.c. */
|
|
|
|
static inline int
|
|
__attribute__ ((always_inline))
|
|
elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
|
|
int lazy, int profile)
|
|
{
|
|
extern void _dl_runtime_resolve (void);
|
|
|
|
if (l->l_info[DT_JMPREL] && lazy)
|
|
{
|
|
/* On ARC DT_PLTGOT point to .plt whose 5th word (after the PLT header)
|
|
contains the address of .got. */
|
|
ElfW(Addr) *plt_base = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
|
|
ElfW(Addr) *got = (ElfW(Addr) *) (plt_base[5] + l->l_addr);
|
|
|
|
got[1] = (ElfW(Addr)) l; /* Identify this shared object. */
|
|
|
|
/* This function will get called to fix up the GOT entry indicated by
|
|
the offset on the stack, and then jump to the resolved address. */
|
|
got[2] = (ElfW(Addr)) &_dl_runtime_resolve;
|
|
}
|
|
|
|
return lazy;
|
|
}
|
|
|
|
/* What this code does:
|
|
-ldso starts execution here when kernel returns from execve
|
|
-calls into generic ldso entry point _dl_start
|
|
-optionally adjusts argc for executable if exec passed as cmd
|
|
-calls into app main with address of finaliser. */
|
|
|
|
#define RTLD_START asm ("\
|
|
.text \n\
|
|
.globl __start \n\
|
|
.type __start, @function \n\
|
|
__start: \n\
|
|
/* (1). bootstrap ld.so. */ \n\
|
|
bl.d _dl_start \n\
|
|
mov_s r0, sp /* pass ptr to aux vector tbl. */ \n\
|
|
mov r13, r0 /* safekeep app elf entry point. */ \n\
|
|
ld_s r1, [sp] /* orig argc. */ \n\
|
|
\n\
|
|
/* (2). call preinit stuff. */ \n\
|
|
ld r0, [pcl, _rtld_local@pcl] \n\
|
|
add r2, sp, 4 ; argv \n\
|
|
add2 r3, r2, r1 \n\
|
|
add r3, r3, 4 ; env \n\
|
|
bl _dl_init@plt \n\
|
|
\n\
|
|
/* (3) call app elf entry point. */ \n\
|
|
add r0, pcl, _dl_fini@pcl \n\
|
|
j [r13] \n\
|
|
\n\
|
|
.size __start,.-__start \n\
|
|
.previous \n\
|
|
");
|
|
|
|
/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
|
|
PLT entries should not be allowed to define the value.
|
|
ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
|
|
of the main executable's symbols, as for a COPY reloc. */
|
|
#define elf_machine_type_class(type) \
|
|
((((type) == R_ARC_JMP_SLOT \
|
|
|| (type) == R_ARC_TLS_DTPMOD \
|
|
|| (type) == R_ARC_TLS_DTPOFF \
|
|
|| (type) == R_ARC_TLS_TPOFF) * ELF_RTYPE_CLASS_PLT) \
|
|
| (((type) == R_ARC_COPY) * ELF_RTYPE_CLASS_COPY))
|
|
|
|
/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
|
|
#define ELF_MACHINE_JMP_SLOT R_ARC_JMP_SLOT
|
|
|
|
/* Fixup a PLT entry to bounce directly to the function at VALUE. */
|
|
|
|
static inline ElfW(Addr)
|
|
elf_machine_fixup_plt (struct link_map *map, lookup_t t,
|
|
const ElfW(Sym) *refsym, const ElfW(Sym) *sym,
|
|
const ElfW(Rela) *reloc,
|
|
ElfW(Addr) *reloc_addr, ElfW(Addr) value)
|
|
{
|
|
return *reloc_addr = value;
|
|
}
|
|
|
|
/* Return the final value of a plt relocation. */
|
|
#define elf_machine_plt_value(map, reloc, value) (value)
|
|
|
|
/* Names of the architecture-specific auditing callback functions. */
|
|
#define ARCH_LA_PLTENTER arc_gnu_pltenter
|
|
#define ARCH_LA_PLTEXIT arc_gnu_pltexit
|
|
|
|
#endif /* dl_machine_h */
|
|
|
|
#ifdef RESOLVE_MAP
|
|
|
|
static inline void
|
|
__attribute__ ((always_inline))
|
|
elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[],
|
|
const ElfW(Rela) *reloc, const ElfW(Sym) *sym,
|
|
const struct r_found_version *version,
|
|
void *const reloc_addr_arg, int skip_ifunc)
|
|
{
|
|
ElfW(Addr) r_info = reloc->r_info;
|
|
const unsigned long int r_type = ELFW (R_TYPE) (r_info);
|
|
ElfW(Addr) *const reloc_addr = reloc_addr_arg;
|
|
|
|
if (__glibc_unlikely (r_type == R_ARC_RELATIVE))
|
|
*reloc_addr += map->l_addr;
|
|
else if (__glibc_unlikely (r_type == R_ARC_NONE))
|
|
return;
|
|
else
|
|
{
|
|
const ElfW(Sym) *const refsym = sym;
|
|
struct link_map *sym_map = RESOLVE_MAP (map, scope, &sym, version,
|
|
r_type);
|
|
ElfW(Addr) value = SYMBOL_ADDRESS (sym_map, sym, true);
|
|
|
|
switch (r_type)
|
|
{
|
|
case R_ARC_COPY:
|
|
if (__glibc_unlikely (sym == NULL))
|
|
/* This can happen in trace mode if an object could not be
|
|
found. */
|
|
break;
|
|
|
|
size_t size = sym->st_size;
|
|
if (__glibc_unlikely (size != refsym->st_size))
|
|
{
|
|
const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
|
|
if (sym->st_size > refsym->st_size)
|
|
size = refsym->st_size;
|
|
if (sym->st_size > refsym->st_size || GLRO(dl_verbose))
|
|
_dl_error_printf ("\
|
|
%s: Symbol `%s' has different size in shared object, consider re-linking\n",
|
|
rtld_progname ?: "<program name unknown>",
|
|
strtab + refsym->st_name);
|
|
}
|
|
|
|
memcpy (reloc_addr_arg, (void *) value, size);
|
|
break;
|
|
|
|
case R_ARC_GLOB_DAT:
|
|
case R_ARC_JMP_SLOT:
|
|
*reloc_addr = value;
|
|
break;
|
|
|
|
case R_ARC_TLS_DTPMOD:
|
|
if (sym_map != NULL)
|
|
/* Get the information from the link map returned by the
|
|
resolv function. */
|
|
*reloc_addr = sym_map->l_tls_modid;
|
|
break;
|
|
|
|
case R_ARC_TLS_DTPOFF:
|
|
if (sym != NULL)
|
|
/* Offset set by the linker in the GOT entry would be overwritten
|
|
by dynamic loader instead of added to the symbol location.
|
|
Other target have the same approach on DTPOFF relocs. */
|
|
*reloc_addr += sym->st_value;
|
|
break;
|
|
|
|
case R_ARC_TLS_TPOFF:
|
|
if (sym != NULL)
|
|
{
|
|
CHECK_STATIC_TLS (map, sym_map);
|
|
*reloc_addr = sym_map->l_tls_offset + sym->st_value + reloc->r_addend;
|
|
}
|
|
break;
|
|
|
|
case R_ARC_32:
|
|
*reloc_addr += value + reloc->r_addend;
|
|
break;
|
|
|
|
case R_ARC_PC32:
|
|
*reloc_addr += value + reloc->r_addend - (unsigned long int) reloc_addr;
|
|
break;
|
|
|
|
default:
|
|
_dl_reloc_bad_type (map, r_type, 0);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline void
|
|
__attribute__ ((always_inline))
|
|
elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
|
|
void *const reloc_addr_arg)
|
|
{
|
|
ElfW(Addr) *const reloc_addr = reloc_addr_arg;
|
|
*reloc_addr += l_addr;
|
|
}
|
|
|
|
static inline void
|
|
__attribute__ ((always_inline))
|
|
elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
|
|
ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
|
|
int skip_ifunc)
|
|
{
|
|
ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
|
|
const unsigned int r_type = ELFW (R_TYPE) (reloc->r_info);
|
|
|
|
if (r_type == R_ARC_JMP_SLOT)
|
|
*reloc_addr += l_addr;
|
|
else
|
|
_dl_reloc_bad_type (map, r_type, 1);
|
|
}
|
|
|
|
#endif /* RESOLVE_MAP */
|