337 lines
10 KiB
C
337 lines
10 KiB
C
/* Machine-dependent ELF dynamic relocation inline functions. Nios II version.
|
|
Copyright (C) 1995-2015 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 "nios2"
|
|
|
|
#include <string.h>
|
|
#include <link.h>
|
|
#include <dl-tls.h>
|
|
|
|
/* Return nonzero iff ELF header is compatible with the running host. */
|
|
static inline int
|
|
elf_machine_matches_host (const Elf32_Ehdr *ehdr)
|
|
{
|
|
return ehdr->e_machine == EM_ALTERA_NIOS2;
|
|
}
|
|
|
|
|
|
/* Return the link-time address of _DYNAMIC. Conveniently, this is the
|
|
first element of the GOT. */
|
|
static inline Elf32_Addr
|
|
elf_machine_dynamic (void)
|
|
{
|
|
Elf32_Addr *dynamic;
|
|
int tmp;
|
|
asm ("nextpc\t%0\n\t"
|
|
"1: movhi\t%1, %%hiadj(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t"
|
|
"addi\t%1, %1, %%lo(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t"
|
|
"add\t%0, %0, %1\n"
|
|
: "=r" (dynamic), "=r" (tmp));
|
|
return *dynamic;
|
|
}
|
|
|
|
|
|
/* Return the run-time load address of the shared object. */
|
|
static inline Elf32_Addr
|
|
elf_machine_load_address (void)
|
|
{
|
|
Elf32_Addr result;
|
|
int tmp;
|
|
asm ("nextpc\t%0\n\t"
|
|
"1: movhi\t%1, %%hiadj(1b)\n\t"
|
|
"addi\t%1, %1, %%lo(1b)\n\t"
|
|
"sub\t%0, %0, %1\n"
|
|
: "=r" (result), "=r" (tmp));
|
|
return result;
|
|
}
|
|
|
|
/* 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, int lazy, int profile)
|
|
{
|
|
extern void _dl_runtime_resolve (Elf32_Word);
|
|
|
|
if (l->l_info[DT_JMPREL] && lazy)
|
|
{
|
|
/* The GOT entries for functions in the PLT have not yet been filled
|
|
in. Their initial contents will arrange when called to load r15 with
|
|
an offset into the .got section, load r14 with
|
|
_GLOBAL_OFFSET_TABLE_[1], and then jump to _GLOBAL_OFFSET_TABLE[2].
|
|
*/
|
|
Elf32_Addr *got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
|
|
got[1] = (Elf32_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] = (Elf32_Addr) &_dl_runtime_resolve;
|
|
}
|
|
|
|
return lazy;
|
|
}
|
|
|
|
/* Initial entry point code for the dynamic linker.
|
|
The C function `_dl_start' is the real entry point;
|
|
its return value is the user program's entry point. */
|
|
|
|
#define RTLD_START asm ("\
|
|
.text\n\
|
|
.globl _start\n\
|
|
.type _start, %function\n\
|
|
_start:\n\
|
|
/* At start time, all the args are on the stack. */\n\
|
|
mov r4, sp\n\
|
|
\n\
|
|
/* Start the calculation of the GOT pointer. */\n\
|
|
nextpc r22\n\
|
|
1: movhi r8, %hiadj(_gp_got - 1b)\n\
|
|
addi r8, r8, %lo(_gp_got - 1b)\n\
|
|
\n\
|
|
/* Figure out where _dl_start will need to return to. */\n\
|
|
movhi ra, %hiadj(2f - 1b)\n\
|
|
addi ra, ra, %lo(2f - 1b)\n\
|
|
add ra, ra, r22\n\
|
|
\n\
|
|
/* Finish the calculation of the GOT pointer. */\n\
|
|
add r22, r22, r8\n\
|
|
\n\
|
|
br _dl_start\n\
|
|
\n\
|
|
/* Save the returned user entry point. */\n\
|
|
2: mov r16, r2\n\
|
|
\n\
|
|
/* Initialize gp. */\n\
|
|
ldw r4, %got(_rtld_local)(r22)\n\
|
|
ldw r4, 0(r4)\n\
|
|
ldw r8, %call(_dl_nios2_get_gp_value)(r22)\n\
|
|
callr r8\n\
|
|
mov gp, r2\n\
|
|
\n\
|
|
/* Find the number of arguments to skip. */\n\
|
|
ldw r8, %got(_dl_skip_args)(r22)\n\
|
|
ldw r8, 0(r8)\n\
|
|
\n\
|
|
/* Find the main_map from the GOT. */\n\
|
|
ldw r4, %got(_rtld_local)(r22)\n\
|
|
ldw r4, 0(r4)\n\
|
|
\n\
|
|
/* Find argc. */\n\
|
|
ldw r5, 0(sp)\n\
|
|
sub r5, r5, r8\n\
|
|
stw r5, 0(sp)\n\
|
|
\n\
|
|
/* Find the first unskipped argument. */\n\
|
|
slli r8, r8, 2\n\
|
|
addi r6, sp, 4\n\
|
|
add r9, r6, r8\n\
|
|
mov r10, r6\n\
|
|
\n\
|
|
/* Shuffle argv down. */\n\
|
|
3: ldw r11, 0(r9)\n\
|
|
stw r11, 0(r10)\n\
|
|
addi r9, r9, 4\n\
|
|
addi r10, r10, 4\n\
|
|
bne r11, zero, 3b\n\
|
|
\n\
|
|
/* Shuffle envp down. */\n\
|
|
mov r7, r10\n\
|
|
4: ldw r11, 0(r9)\n\
|
|
stw r11, 0(r10)\n\
|
|
addi r9, r9, 4\n\
|
|
addi r10, r10, 4\n\
|
|
bne r11, zero, 4b\n\
|
|
\n\
|
|
/* Shuffle auxv down. */\n\
|
|
5: ldw r11, 4(r9)\n\
|
|
stw r11, 4(r10)\n\
|
|
ldw r11, 0(r9)\n\
|
|
stw r11, 0(r10)\n\
|
|
addi r9, r9, 8\n\
|
|
addi r10, r10, 8\n\
|
|
bne r11, zero, 5b\n\
|
|
\n\
|
|
/* Update _dl_argv. */\n\
|
|
ldw r2, %got(_dl_argv)(r22)\n\
|
|
stw r6, 0(r2)\n\
|
|
\n\
|
|
/* Call _dl_init through the PLT. */\n\
|
|
ldw r8, %call(_dl_init)(r22)\n\
|
|
callr r8\n\
|
|
\n\
|
|
/* Find the finalization function. */\n\
|
|
ldw r4, %got(_dl_fini)(r22)\n\
|
|
\n\
|
|
/* Jump to the user's entry point. */\n\
|
|
jmp r16\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_COPY 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_NIOS2_JUMP_SLOT \
|
|
|| (type) == R_NIOS2_TLS_DTPMOD \
|
|
|| (type) == R_NIOS2_TLS_DTPREL \
|
|
|| (type) == R_NIOS2_TLS_TPREL) * ELF_RTYPE_CLASS_PLT) \
|
|
| (((type) == R_NIOS2_COPY) * ELF_RTYPE_CLASS_COPY) \
|
|
| (((type) == R_NIOS2_GLOB_DAT) * ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA))
|
|
|
|
/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
|
|
#define ELF_MACHINE_JMP_SLOT R_NIOS2_JUMP_SLOT
|
|
|
|
/* The Nios II never uses Elf32_Rel relocations. */
|
|
#define ELF_MACHINE_NO_REL 1
|
|
#define ELF_MACHINE_NO_RELA 0
|
|
|
|
/* Fixup a PLT entry to bounce directly to the function at VALUE. */
|
|
|
|
static inline Elf32_Addr
|
|
elf_machine_fixup_plt (struct link_map *map, lookup_t t,
|
|
const Elf32_Rela *reloc,
|
|
Elf32_Addr *reloc_addr, Elf32_Addr value)
|
|
{
|
|
return *reloc_addr = value;
|
|
}
|
|
|
|
/* Return the final value of a plt relocation. */
|
|
static inline Elf32_Addr
|
|
elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
|
|
Elf32_Addr value)
|
|
{
|
|
return value;
|
|
}
|
|
|
|
/* Names of the architecture-specific auditing callback functions. */
|
|
#define ARCH_LA_PLTENTER nios2_gnu_pltenter
|
|
#define ARCH_LA_PLTEXIT nios2_gnu_pltexit
|
|
|
|
#endif /* dl_machine_h */
|
|
|
|
#ifdef RESOLVE_MAP
|
|
|
|
/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
|
|
LOADADDR is the load address of the object; INFO is an array indexed
|
|
by DT_* of the .dynamic section info. */
|
|
|
|
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)
|
|
{
|
|
Elf32_Addr *const reloc_addr = reloc_addr_arg;
|
|
const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
|
|
|
|
if (__glibc_unlikely (r_type == R_NIOS2_RELATIVE))
|
|
*reloc_addr = map->l_addr + reloc->r_addend;
|
|
else if (__glibc_unlikely (r_type == R_NIOS2_NONE))
|
|
return;
|
|
else
|
|
{
|
|
const Elf32_Sym *const refsym = sym;
|
|
struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
|
|
Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
|
|
|
|
switch (r_type)
|
|
{
|
|
case R_NIOS2_COPY:
|
|
if (sym == NULL)
|
|
/* This can happen in trace mode if an object could not be
|
|
found. */
|
|
break;
|
|
if (sym->st_size > refsym->st_size
|
|
|| (sym->st_size < refsym->st_size && GLRO(dl_verbose)))
|
|
{
|
|
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 ?: "<program name unknown>",
|
|
strtab + refsym->st_name);
|
|
}
|
|
memcpy (reloc_addr_arg, (void *) value,
|
|
MIN (sym->st_size, refsym->st_size));
|
|
break;
|
|
case R_NIOS2_GLOB_DAT:
|
|
case R_NIOS2_JUMP_SLOT:
|
|
# ifdef RTLD_BOOTSTRAP
|
|
/* Fix weak undefined references. */
|
|
if (sym != NULL && sym->st_value == 0)
|
|
*reloc_addr = 0;
|
|
else
|
|
# endif
|
|
*reloc_addr = value;
|
|
break;
|
|
#ifndef RTLD_BOOTSTRAP
|
|
case R_NIOS2_TLS_DTPMOD:
|
|
/* Get the information from the link map returned by the
|
|
resolv function. */
|
|
if (sym_map != NULL)
|
|
*reloc_addr = sym_map->l_tls_modid;
|
|
break;
|
|
|
|
case R_NIOS2_TLS_DTPREL:
|
|
*reloc_addr = reloc->r_addend + TLS_DTPREL_VALUE(sym);
|
|
break;
|
|
|
|
case R_NIOS2_TLS_TPREL:
|
|
if (sym != NULL)
|
|
{
|
|
CHECK_STATIC_TLS (map, sym_map);
|
|
*reloc_addr = reloc->r_addend + TLS_TPREL_VALUE(sym_map, sym);
|
|
}
|
|
break;
|
|
#endif
|
|
case R_NIOS2_BFD_RELOC_32:
|
|
*reloc_addr = value + reloc->r_addend;
|
|
break;
|
|
|
|
default:
|
|
_dl_reloc_bad_type (map, r_type, 0);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
auto inline void __attribute__((always_inline))
|
|
elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
|
|
void *const reloc_addr_arg)
|
|
{
|
|
Elf32_Addr *const reloc_addr = reloc_addr_arg;
|
|
*reloc_addr = l_addr + reloc->r_addend;
|
|
}
|
|
|
|
auto inline void __attribute__((always_inline))
|
|
elf_machine_lazy_rel (struct link_map *map,
|
|
ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
|
|
int skip_ifunc)
|
|
{
|
|
Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
|
|
if (ELF32_R_TYPE (reloc->r_info) == R_NIOS2_JUMP_SLOT)
|
|
*reloc_addr += l_addr;
|
|
else
|
|
_dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1);
|
|
}
|
|
|
|
#endif /* RESOLVE_MAP */
|