mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 13:30:06 +00:00
e9177fba13
We rely on the symbol being locally defined so using extern symbol is not correct and the linker may complain about the relocations.
449 lines
13 KiB
C
449 lines
13 KiB
C
/* Copyright (C) 1995-2017 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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#ifndef dl_machine_h
|
|
#define dl_machine_h
|
|
|
|
#define ELF_MACHINE_NAME "aarch64"
|
|
|
|
#include <sysdep.h>
|
|
#include <tls.h>
|
|
#include <dl-tlsdesc.h>
|
|
#include <dl-irel.h>
|
|
#include <cpu-features.c>
|
|
|
|
/* Return nonzero iff ELF header is compatible with the running host. */
|
|
static inline int __attribute__ ((unused))
|
|
elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
|
|
{
|
|
return ehdr->e_machine == EM_AARCH64;
|
|
}
|
|
|
|
/* Return the link-time address of _DYNAMIC. Conveniently, this is the
|
|
first element of the GOT. */
|
|
static inline ElfW(Addr) __attribute__ ((unused))
|
|
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) __attribute__ ((unused))
|
|
elf_machine_load_address (void)
|
|
{
|
|
/* To figure out the load address we use the definition that for any symbol:
|
|
dynamic_addr(symbol) = static_addr(symbol) + load_addr
|
|
|
|
The choice of symbol is arbitrary. The static address we obtain
|
|
by constructing a non GOT reference to the symbol, the dynamic
|
|
address of the symbol we compute using adrp/add to compute the
|
|
symbol's address relative to the PC.
|
|
This depends on 32/16bit relocations being resolved at link time
|
|
and that the static address fits in the 32/16 bits. */
|
|
|
|
ElfW(Addr) static_addr;
|
|
ElfW(Addr) dynamic_addr;
|
|
|
|
asm (" \n"
|
|
" adrp %1, _dl_start; \n"
|
|
#ifdef __LP64__
|
|
" add %1, %1, #:lo12:_dl_start \n"
|
|
#else
|
|
" add %w1, %w1, #:lo12:_dl_start \n"
|
|
#endif
|
|
" ldr %w0, 1f \n"
|
|
" b 2f \n"
|
|
"1: \n"
|
|
#ifdef __LP64__
|
|
" .word _dl_start \n"
|
|
#else
|
|
# ifdef __AARCH64EB__
|
|
" .short 0 \n"
|
|
# endif
|
|
" .short _dl_start \n"
|
|
# ifndef __AARCH64EB__
|
|
" .short 0 \n"
|
|
# endif
|
|
#endif
|
|
"2: \n"
|
|
: "=r" (static_addr), "=r" (dynamic_addr));
|
|
return dynamic_addr - static_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__ ((unused))
|
|
elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
|
|
{
|
|
if (l->l_info[DT_JMPREL] && lazy)
|
|
{
|
|
ElfW(Addr) *got;
|
|
extern void _dl_runtime_resolve (ElfW(Word));
|
|
extern void _dl_runtime_profile (ElfW(Word));
|
|
|
|
got = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
|
|
if (got[1])
|
|
{
|
|
l->l_mach.plt = got[1] + l->l_addr;
|
|
}
|
|
got[1] = (ElfW(Addr)) l;
|
|
|
|
/* The got[2] entry contains the address of a function which gets
|
|
called to get the address of a so far unresolved function and
|
|
jump to it. The profiling extension of the dynamic linker allows
|
|
to intercept the calls to collect information. In this case we
|
|
don't store the address in the GOT so that all future calls also
|
|
end in this function. */
|
|
if ( profile)
|
|
{
|
|
got[2] = (ElfW(Addr)) &_dl_runtime_profile;
|
|
|
|
if (GLRO(dl_profile) != NULL
|
|
&& _dl_name_match_p (GLRO(dl_profile), l))
|
|
/* Say that we really want profiling and the timers are
|
|
started. */
|
|
GL(dl_profile_map) = l;
|
|
}
|
|
else
|
|
{
|
|
/* 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;
|
|
}
|
|
}
|
|
|
|
if (l->l_info[ADDRIDX (DT_TLSDESC_GOT)] && lazy)
|
|
*(ElfW(Addr)*)(D_PTR (l, l_info[ADDRIDX (DT_TLSDESC_GOT)]) + l->l_addr)
|
|
= (ElfW(Addr)) &_dl_tlsdesc_resolve_rela;
|
|
|
|
return lazy;
|
|
}
|
|
|
|
/* Initial entry point for the dynamic linker. The C function
|
|
_dl_start is the real entry point, its return value is the user
|
|
program's entry point */
|
|
#ifdef __LP64__
|
|
# define RTLD_START RTLD_START_1 ("x", "3", "sp")
|
|
#else
|
|
# define RTLD_START RTLD_START_1 ("w", "2", "wsp")
|
|
#endif
|
|
|
|
|
|
#define RTLD_START_1(PTR, PTR_SIZE_LOG, PTR_SP) asm ("\
|
|
.text \n\
|
|
.globl _start \n\
|
|
.type _start, %function \n\
|
|
.globl _dl_start_user \n\
|
|
.type _dl_start_user, %function \n\
|
|
_start: \n\
|
|
mov " PTR "0, " PTR_SP " \n\
|
|
bl _dl_start \n\
|
|
// returns user entry point in x0 \n\
|
|
mov x21, x0 \n\
|
|
_dl_start_user: \n\
|
|
// get the original arg count \n\
|
|
ldr " PTR "1, [sp] \n\
|
|
// get the argv address \n\
|
|
add " PTR "2, " PTR_SP ", #(1<<" PTR_SIZE_LOG ") \n\
|
|
// get _dl_skip_args to see if we were \n\
|
|
// invoked as an executable \n\
|
|
adrp x4, _dl_skip_args \n\
|
|
ldr w4, [x4, #:lo12:_dl_skip_args] \n\
|
|
// do we need to adjust argc/argv \n\
|
|
cmp w4, 0 \n\
|
|
beq .L_done_stack_adjust \n\
|
|
// subtract _dl_skip_args from original arg count \n\
|
|
sub " PTR "1, " PTR "1, " PTR "4 \n\
|
|
// store adjusted argc back to stack \n\
|
|
str " PTR "1, [sp] \n\
|
|
// find the first unskipped argument \n\
|
|
mov " PTR "3, " PTR "2 \n\
|
|
add " PTR "4, " PTR "2, " PTR "4, lsl #" PTR_SIZE_LOG " \n\
|
|
// shuffle argv down \n\
|
|
1: ldr " PTR "5, [x4], #(1<<" PTR_SIZE_LOG ") \n\
|
|
str " PTR "5, [x3], #(1<<" PTR_SIZE_LOG ") \n\
|
|
cmp " PTR "5, #0 \n\
|
|
bne 1b \n\
|
|
// shuffle envp down \n\
|
|
1: ldr " PTR "5, [x4], #(1<<" PTR_SIZE_LOG ") \n\
|
|
str " PTR "5, [x3], #(1<<" PTR_SIZE_LOG ") \n\
|
|
cmp " PTR "5, #0 \n\
|
|
bne 1b \n\
|
|
// shuffle auxv down \n\
|
|
1: ldp " PTR "0, " PTR "5, [x4, #(2<<" PTR_SIZE_LOG ")]! \n\
|
|
stp " PTR "0, " PTR "5, [x3], #(2<<" PTR_SIZE_LOG ") \n\
|
|
cmp " PTR "0, #0 \n\
|
|
bne 1b \n\
|
|
// Update _dl_argv \n\
|
|
adrp x3, __GI__dl_argv \n\
|
|
str " PTR "2, [x3, #:lo12:__GI__dl_argv] \n\
|
|
.L_done_stack_adjust: \n\
|
|
// compute envp \n\
|
|
add " PTR "3, " PTR "2, " PTR "1, lsl #" PTR_SIZE_LOG " \n\
|
|
add " PTR "3, " PTR "3, #(1<<" PTR_SIZE_LOG ") \n\
|
|
adrp x16, _rtld_local \n\
|
|
add " PTR "16, " PTR "16, #:lo12:_rtld_local \n\
|
|
ldr " PTR "0, [x16] \n\
|
|
bl _dl_init \n\
|
|
// load the finalizer function \n\
|
|
adrp x0, _dl_fini \n\
|
|
add " PTR "0, " PTR "0, #:lo12:_dl_fini \n\
|
|
// jump to the user_s entry point \n\
|
|
br x21 \n\
|
|
");
|
|
|
|
#define elf_machine_type_class(type) \
|
|
((((type) == AARCH64_R(JUMP_SLOT) \
|
|
|| (type) == AARCH64_R(TLS_DTPMOD) \
|
|
|| (type) == AARCH64_R(TLS_DTPREL) \
|
|
|| (type) == AARCH64_R(TLS_TPREL) \
|
|
|| (type) == AARCH64_R(TLSDESC)) * ELF_RTYPE_CLASS_PLT) \
|
|
| (((type) == AARCH64_R(COPY)) * ELF_RTYPE_CLASS_COPY) \
|
|
| (((type) == AARCH64_R(GLOB_DAT)) * ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA))
|
|
|
|
#define ELF_MACHINE_JMP_SLOT AARCH64_R(JUMP_SLOT)
|
|
|
|
/* AArch64 uses RELA not REL */
|
|
#define ELF_MACHINE_NO_REL 1
|
|
#define ELF_MACHINE_NO_RELA 0
|
|
|
|
#define DL_PLATFORM_INIT dl_platform_init ()
|
|
|
|
static inline void __attribute__ ((unused))
|
|
dl_platform_init (void)
|
|
{
|
|
if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
|
|
/* Avoid an empty string which would disturb us. */
|
|
GLRO(dl_platform) = NULL;
|
|
|
|
#ifdef SHARED
|
|
/* init_cpu_features has been called early from __libc_start_main in
|
|
static executable. */
|
|
init_cpu_features (&GLRO(dl_aarch64_cpu_features));
|
|
#endif
|
|
}
|
|
|
|
|
|
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. */
|
|
static inline ElfW(Addr)
|
|
elf_machine_plt_value (struct link_map *map,
|
|
const ElfW(Rela) *reloc,
|
|
ElfW(Addr) value)
|
|
{
|
|
return value;
|
|
}
|
|
|
|
#endif
|
|
|
|
/* Names of the architecture-specific auditing callback functions. */
|
|
#define ARCH_LA_PLTENTER aarch64_gnu_pltenter
|
|
#define ARCH_LA_PLTEXIT aarch64_gnu_pltexit
|
|
|
|
#ifdef RESOLVE_MAP
|
|
|
|
auto inline void
|
|
__attribute__ ((always_inline))
|
|
elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
|
|
const ElfW(Sym) *sym, const struct r_found_version *version,
|
|
void *const reloc_addr_arg, int skip_ifunc)
|
|
{
|
|
ElfW(Addr) *const reloc_addr = reloc_addr_arg;
|
|
const unsigned int r_type = ELFW (R_TYPE) (reloc->r_info);
|
|
|
|
if (__builtin_expect (r_type == AARCH64_R(RELATIVE), 0))
|
|
*reloc_addr = map->l_addr + reloc->r_addend;
|
|
else if (__builtin_expect (r_type == R_AARCH64_NONE, 0))
|
|
return;
|
|
else
|
|
{
|
|
const ElfW(Sym) *const refsym = sym;
|
|
struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
|
|
ElfW(Addr) value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
|
|
|
|
if (sym != NULL
|
|
&& __glibc_unlikely (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC)
|
|
&& __glibc_likely (sym->st_shndx != SHN_UNDEF)
|
|
&& __glibc_likely (!skip_ifunc))
|
|
value = elf_ifunc_invoke (value);
|
|
|
|
switch (r_type)
|
|
{
|
|
case AARCH64_R(COPY):
|
|
if (sym == NULL)
|
|
break;
|
|
|
|
if (sym->st_size > refsym->st_size
|
|
|| (GLRO(dl_verbose) && sym->st_size < refsym->st_size))
|
|
{
|
|
const char *strtab;
|
|
|
|
strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
|
|
_dl_error_printf ("\
|
|
%s: Symbol `%s' has different size in shared object, consider re-linking\n",
|
|
RTLD_PROGNAME, strtab + refsym->st_name);
|
|
}
|
|
memcpy (reloc_addr_arg, (void *) value,
|
|
MIN (sym->st_size, refsym->st_size));
|
|
break;
|
|
|
|
case AARCH64_R(RELATIVE):
|
|
case AARCH64_R(GLOB_DAT):
|
|
case AARCH64_R(JUMP_SLOT):
|
|
case AARCH64_R(ABS32):
|
|
#ifdef __LP64__
|
|
case AARCH64_R(ABS64):
|
|
#endif
|
|
*reloc_addr = value + reloc->r_addend;
|
|
break;
|
|
|
|
case AARCH64_R(TLSDESC):
|
|
{
|
|
struct tlsdesc volatile *td =
|
|
(struct tlsdesc volatile *)reloc_addr;
|
|
#ifndef RTLD_BOOTSTRAP
|
|
if (! sym)
|
|
{
|
|
td->arg = (void*)reloc->r_addend;
|
|
td->entry = _dl_tlsdesc_undefweak;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
#ifndef RTLD_BOOTSTRAP
|
|
# ifndef SHARED
|
|
CHECK_STATIC_TLS (map, sym_map);
|
|
# else
|
|
if (!TRY_STATIC_TLS (map, sym_map))
|
|
{
|
|
td->arg = _dl_make_tlsdesc_dynamic
|
|
(sym_map, sym->st_value + reloc->r_addend);
|
|
td->entry = _dl_tlsdesc_dynamic;
|
|
}
|
|
else
|
|
# endif
|
|
#endif
|
|
{
|
|
td->arg = (void*)(sym->st_value + sym_map->l_tls_offset
|
|
+ reloc->r_addend);
|
|
td->entry = _dl_tlsdesc_return;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
case AARCH64_R(TLS_DTPMOD):
|
|
#ifdef RTLD_BOOTSTRAP
|
|
*reloc_addr = 1;
|
|
#else
|
|
if (sym_map != NULL)
|
|
{
|
|
*reloc_addr = sym_map->l_tls_modid;
|
|
}
|
|
#endif
|
|
break;
|
|
|
|
case AARCH64_R(TLS_DTPREL):
|
|
if (sym)
|
|
*reloc_addr = sym->st_value + reloc->r_addend;
|
|
break;
|
|
|
|
case AARCH64_R(TLS_TPREL):
|
|
if (sym)
|
|
{
|
|
CHECK_STATIC_TLS (map, sym_map);
|
|
*reloc_addr =
|
|
sym->st_value + reloc->r_addend + sym_map->l_tls_offset;
|
|
}
|
|
break;
|
|
|
|
case AARCH64_R(IRELATIVE):
|
|
value = map->l_addr + reloc->r_addend;
|
|
value = elf_ifunc_invoke (value);
|
|
*reloc_addr = value;
|
|
break;
|
|
|
|
default:
|
|
_dl_reloc_bad_type (map, r_type, 0);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
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 + reloc->r_addend;
|
|
}
|
|
|
|
inline void
|
|
__attribute__ ((always_inline))
|
|
elf_machine_lazy_rel (struct link_map *map,
|
|
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);
|
|
/* Check for unexpected PLT reloc type. */
|
|
if (__builtin_expect (r_type == AARCH64_R(JUMP_SLOT), 1))
|
|
{
|
|
if (__builtin_expect (map->l_mach.plt, 0) == 0)
|
|
*reloc_addr += l_addr;
|
|
else
|
|
*reloc_addr = map->l_mach.plt;
|
|
}
|
|
else if (__builtin_expect (r_type == AARCH64_R(TLSDESC), 1))
|
|
{
|
|
struct tlsdesc volatile *td =
|
|
(struct tlsdesc volatile *)reloc_addr;
|
|
|
|
td->arg = (void*)reloc;
|
|
td->entry = (void*)(D_PTR (map, l_info[ADDRIDX (DT_TLSDESC_PLT)])
|
|
+ map->l_addr);
|
|
}
|
|
else if (__glibc_unlikely (r_type == AARCH64_R(IRELATIVE)))
|
|
{
|
|
ElfW(Addr) value = map->l_addr + reloc->r_addend;
|
|
if (__glibc_likely (!skip_ifunc))
|
|
value = elf_ifunc_invoke (value);
|
|
*reloc_addr = value;
|
|
}
|
|
else
|
|
_dl_reloc_bad_type (map, r_type, 1);
|
|
}
|
|
|
|
#endif
|