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glibc/sysdeps/sparc/sparc32/dl-machine.h
H.J. Lu 9bac1d8624 Define VERSYMIDX/VALIDX/ADDRIDX in ldsodefs.h
2012-09-28 11:30:57 -07:00

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/* Machine-dependent ELF dynamic relocation inline functions. SPARC version.
Copyright (C) 1996-2003, 2004, 2005, 2006, 2007, 2010, 2011, 2012
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 "sparc"
#include <string.h>
#include <sys/param.h>
#include <ldsodefs.h>
#include <sysdep.h>
#include <tls.h>
#include <dl-plt.h>
/* Return nonzero iff ELF header is compatible with the running host. */
static inline int
elf_machine_matches_host (const Elf32_Ehdr *ehdr)
{
if (ehdr->e_machine == EM_SPARC)
return 1;
else if (ehdr->e_machine == EM_SPARC32PLUS)
{
/* XXX The following is wrong! Dave Miller rejected to implement it
correctly. If this causes problems shoot *him*! */
#ifdef SHARED
return GLRO(dl_hwcap) & GLRO(dl_hwcap_mask) & HWCAP_SPARC_V9;
#else
return GLRO(dl_hwcap) & HWCAP_SPARC_V9;
#endif
}
else
return 0;
}
/* We have to do this because elf_machine_{dynamic,load_address} can be
invoked from functions that have no GOT references, and thus the compiler
has no obligation to load the PIC register. */
#define LOAD_PIC_REG(PIC_REG) \
do { register Elf32_Addr pc __asm("o7"); \
__asm("sethi %%hi(_GLOBAL_OFFSET_TABLE_-4), %1\n\t" \
"call 1f\n\t" \
"add %1, %%lo(_GLOBAL_OFFSET_TABLE_+4), %1\n" \
"1:\tadd %1, %0, %1" \
: "=r" (pc), "=r" (PIC_REG)); \
} while (0)
/* Return the link-time address of _DYNAMIC. Conveniently, this is the
first element of the GOT. This must be inlined in a function which
uses global data. */
static inline Elf32_Addr
elf_machine_dynamic (void)
{
register Elf32_Addr *got asm ("%l7");
LOAD_PIC_REG (got);
return *got;
}
/* Return the run-time load address of the shared object. */
static inline Elf32_Addr
elf_machine_load_address (void)
{
register Elf32_Addr *pc __asm ("%o7"), *got __asm ("%l7");
__asm ("sethi %%hi(_GLOBAL_OFFSET_TABLE_-4), %1\n\t"
"call 1f\n\t"
" add %1, %%lo(_GLOBAL_OFFSET_TABLE_+4), %1\n\t"
"call _DYNAMIC\n\t"
"call _GLOBAL_OFFSET_TABLE_\n"
"1:\tadd %1, %0, %1\n\t" : "=r" (pc), "=r" (got));
/* got is now l_addr + _GLOBAL_OFFSET_TABLE_
*got is _DYNAMIC
pc[2]*4 is l_addr + _DYNAMIC - (long)pc - 8
pc[3]*4 is l_addr + _GLOBAL_OFFSET_TABLE_ - (long)pc - 12 */
return (Elf32_Addr) got - *got + (pc[2] - pc[3]) * 4 - 4;
}
/* 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
elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
{
Elf32_Addr *plt;
extern void _dl_runtime_resolve (Elf32_Word);
extern void _dl_runtime_profile (Elf32_Word);
if (l->l_info[DT_JMPREL] && lazy)
{
Elf32_Addr rfunc;
/* The entries for functions in the PLT have not yet been filled in.
Their initial contents will arrange when called to set the high 22
bits of %g1 with an offset into the .rela.plt section and jump to
the beginning of the PLT. */
plt = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
if (__builtin_expect(profile, 0))
{
rfunc = (Elf32_Addr) &_dl_runtime_profile;
if (GLRO(dl_profile) != NULL
&& _dl_name_match_p (GLRO(dl_profile), l))
GL(dl_profile_map) = l;
}
else
{
rfunc = (Elf32_Addr) &_dl_runtime_resolve;
}
/* The beginning of the PLT does:
sethi %hi(_dl_runtime_{resolve,profile}), %g2
pltpc: jmpl %g2 + %lo(_dl_runtime_{resolve,profile}), %g2
nop
.word MAP
The PC value (pltpc) saved in %g2 by the jmpl points near the
location where we store the link_map pointer for this object. */
plt[0] = 0x05000000 | ((rfunc >> 10) & 0x003fffff);
plt[1] = 0x85c0a000 | (rfunc & 0x3ff);
plt[2] = OPCODE_NOP; /* Fill call delay slot. */
plt[3] = (Elf32_Addr) l;
if (__builtin_expect (l->l_info[VALIDX(DT_GNU_PRELINKED)] != NULL, 0)
|| __builtin_expect (l->l_info [VALIDX (DT_GNU_LIBLISTSZ)] != NULL, 0))
{
/* Need to reinitialize .plt to undo prelinking. */
Elf32_Rela *rela = (Elf32_Rela *) D_PTR (l, l_info[DT_JMPREL]);
Elf32_Rela *relaend
= (Elf32_Rela *) ((char *) rela
+ l->l_info[DT_PLTRELSZ]->d_un.d_val);
#if !defined RTLD_BOOTSTRAP && !defined __sparc_v9__
/* Note that we don't mask the hwcap here, as the flush is
essential to functionality on those cpu's that implement it.
For sparcv9 we can assume flush is present. */
const int do_flush = GLRO(dl_hwcap) & HWCAP_SPARC_FLUSH;
#else
const int do_flush = 1;
#endif
/* prelink must ensure there are no R_SPARC_NONE relocs left
in .rela.plt. */
while (rela < relaend)
{
*(unsigned int *) (rela->r_offset + l->l_addr)
= OPCODE_SETHI_G1 | (rela->r_offset + l->l_addr
- (Elf32_Addr) plt);
*(unsigned int *) (rela->r_offset + l->l_addr + 4)
= OPCODE_BA | ((((Elf32_Addr) plt
- rela->r_offset - l->l_addr - 4) >> 2)
& 0x3fffff);
if (do_flush)
{
__asm __volatile ("flush %0" : : "r" (rela->r_offset
+ l->l_addr));
__asm __volatile ("flush %0+4" : : "r" (rela->r_offset
+ l->l_addr));
}
++rela;
}
}
}
return lazy;
}
/* 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_SPARC_JMP_SLOT \
|| ((type) >= R_SPARC_TLS_GD_HI22 && (type) <= R_SPARC_TLS_TPOFF64)) \
* ELF_RTYPE_CLASS_PLT) \
| (((type) == R_SPARC_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_SPARC_JMP_SLOT
/* The SPARC never uses Elf32_Rel relocations. */
#define ELF_MACHINE_NO_REL 1
/* Undo the sub %sp, 6*4, %sp; add %sp, 22*4, %o0 below to get at the
value we want in __libc_stack_end. */
#define DL_STACK_END(cookie) \
((void *) (((long) (cookie)) - (22 - 6) * 4))
/* 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_GOT_ADDRESS(pic_reg, reg, symbol) \
"sethi %gdop_hix22(" #symbol "), " #reg "\n\t" \
"xor " #reg ", %gdop_lox10(" #symbol "), " #reg "\n\t" \
"ld [" #pic_reg " + " #reg "], " #reg ", %gdop(" #symbol ")"
#define RTLD_START __asm__ ("\
.text\n\
.globl _start\n\
.type _start, @function\n\
.align 32\n\
_start:\n\
/* Allocate space for functions to drop their arguments. */\n\
sub %sp, 6*4, %sp\n\
/* Pass pointer to argument block to _dl_start. */\n\
call _dl_start\n\
add %sp, 22*4, %o0\n\
/* FALTHRU */\n\
.globl _dl_start_user\n\
.type _dl_start_user, @function\n\
_dl_start_user:\n\
/* Load the PIC register. */\n\
1: call 2f\n\
sethi %hi(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n\
2: or %l7, %lo(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n\
add %l7, %o7, %l7\n\
/* Save the user entry point address in %l0 */\n\
mov %o0, %l0\n\
/* See if we were run as a command with the executable file name as an\n\
extra leading argument. If so, adjust the contents of the stack. */\n\
" RTLD_GOT_ADDRESS(%l7, %g2, _dl_skip_args) "\n\
ld [%g2], %i0\n\
tst %i0\n\
beq 3f\n\
ld [%sp+22*4], %i5 /* load argc */\n\
/* Find out how far to shift. */\n\
" RTLD_GOT_ADDRESS(%l7, %l3, _dl_argv) "\n\
sub %i5, %i0, %i5\n\
ld [%l3], %l4\n\
sll %i0, 2, %i2\n\
st %i5, [%sp+22*4]\n\
sub %l4, %i2, %l4\n\
add %sp, 23*4, %i1\n\
add %i1, %i2, %i2\n\
st %l4, [%l3]\n\
/* Copy down argv */\n\
21: ld [%i2], %i3\n\
add %i2, 4, %i2\n\
tst %i3\n\
st %i3, [%i1]\n\
bne 21b\n\
add %i1, 4, %i1\n\
/* Copy down env */\n\
22: ld [%i2], %i3\n\
add %i2, 4, %i2\n\
tst %i3\n\
st %i3, [%i1]\n\
bne 22b\n\
add %i1, 4, %i1\n\
/* Copy down auxiliary table. */\n\
23: ld [%i2], %i3\n\
ld [%i2+4], %i4\n\
add %i2, 8, %i2\n\
tst %i3\n\
st %i3, [%i1]\n\
st %i4, [%i1+4]\n\
bne 23b\n\
add %i1, 8, %i1\n\
/* %o0 = _dl_loaded, %o1 = argc, %o2 = argv, %o3 = envp. */\n\
3: " RTLD_GOT_ADDRESS(%l7, %o0, _rtld_local) "\n\
add %sp, 23*4, %o2\n\
sll %i5, 2, %o3\n\
add %o3, 4, %o3\n\
mov %i5, %o1\n\
add %o2, %o3, %o3\n\
call _dl_init_internal\n\
ld [%o0], %o0\n\
/* Pass our finalizer function to the user in %g1. */\n\
" RTLD_GOT_ADDRESS(%l7, %g1, _dl_fini) "\n\
/* Jump to the user's entry point and deallocate the extra stack we got. */\n\
jmp %l0\n\
add %sp, 6*4, %sp\n\
.size _dl_start_user, . - _dl_start_user\n\
.previous");
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)
{
#ifdef __sparc_v9__
/* Sparc v9 can assume flush is always present. */
const int do_flush = 1;
#else
/* Note that we don't mask the hwcap here, as the flush is essential to
functionality on those cpu's that implement it. */
const int do_flush = GLRO(dl_hwcap) & HWCAP_SPARC_FLUSH;
#endif
return sparc_fixup_plt (reloc, reloc_addr, value, 1, do_flush);
}
/* 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 + reloc->r_addend;
}
#endif /* dl_machine_h */
#define ARCH_LA_PLTENTER sparc32_gnu_pltenter
#define ARCH_LA_PLTEXIT sparc32_gnu_pltexit
#ifdef RESOLVE_MAP
/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
MAP is the object containing the reloc. */
auto inline void
__attribute__ ((always_inline))
elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
const Elf32_Sym *sym, const struct r_found_version *version,
void *const reloc_addr_arg, int skip_ifunc)
{
Elf32_Addr *const reloc_addr = reloc_addr_arg;
#if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP
const Elf32_Sym *const refsym = sym;
#endif
Elf32_Addr value;
const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
#if !defined RESOLVE_CONFLICT_FIND_MAP
struct link_map *sym_map = NULL;
#endif
#if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
/* This is defined in rtld.c, but nowhere in the static libc.a; make the
reference weak so static programs can still link. This declaration
cannot be done when compiling rtld.c (i.e. #ifdef RTLD_BOOTSTRAP)
because rtld.c contains the common defn for _dl_rtld_map, which is
incompatible with a weak decl in the same file. */
weak_extern (_dl_rtld_map);
#endif
if (__builtin_expect (r_type == R_SPARC_NONE, 0))
return;
if (__builtin_expect (r_type == R_SPARC_SIZE32, 0))
{
*reloc_addr = sym->st_size + reloc->r_addend;
return;
}
#if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
if (__builtin_expect (r_type == R_SPARC_RELATIVE, 0))
{
# if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
if (map != &_dl_rtld_map) /* Already done in rtld itself. */
# endif
*reloc_addr += map->l_addr + reloc->r_addend;
return;
}
#endif
#ifndef RESOLVE_CONFLICT_FIND_MAP
if (__builtin_expect (ELF32_ST_BIND (sym->st_info) == STB_LOCAL, 0)
&& sym->st_shndx != SHN_UNDEF)
{
value = map->l_addr;
}
else
{
sym_map = RESOLVE_MAP (&sym, version, r_type);
value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
}
#else
value = 0;
#endif
value += reloc->r_addend; /* Assume copy relocs have zero addend. */
if (sym != NULL
&& __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
&& __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
&& __builtin_expect (!skip_ifunc, 1))
{
value = ((Elf32_Addr (*) (int)) value) (GLRO(dl_hwcap));
}
switch (r_type)
{
#if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP
case R_SPARC_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
|| (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 ?: "<program name unknown>",
strtab + refsym->st_name);
}
memcpy (reloc_addr_arg, (void *) value,
MIN (sym->st_size, refsym->st_size));
break;
#endif
case R_SPARC_GLOB_DAT:
case R_SPARC_32:
*reloc_addr = value;
break;
case R_SPARC_IRELATIVE:
value = ((Elf32_Addr (*) (int)) value) (GLRO(dl_hwcap));
*reloc_addr = value;
break;
case R_SPARC_JMP_IREL:
value = ((Elf32_Addr (*) (int)) value) (GLRO(dl_hwcap));
/* Fall thru */
case R_SPARC_JMP_SLOT:
{
#if !defined RTLD_BOOTSTRAP && !defined __sparc_v9__
/* Note that we don't mask the hwcap here, as the flush is
essential to functionality on those cpu's that implement
it. For sparcv9 we can assume flush is present. */
const int do_flush = GLRO(dl_hwcap) & HWCAP_SPARC_FLUSH;
#else
/* Unfortunately, this is necessary, so that we can ensure
ld.so will not execute corrupt PLT entry instructions. */
const int do_flush = 1;
#endif
/* At this point we don't need to bother with thread safety,
so we can optimize the first instruction of .plt out. */
sparc_fixup_plt (reloc, reloc_addr, value, 0, do_flush);
}
break;
#ifndef RESOLVE_CONFLICT_FIND_MAP
case R_SPARC_TLS_DTPMOD32:
/* 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_SPARC_TLS_DTPOFF32:
/* During relocation all TLS symbols are defined and used.
Therefore the offset is already correct. */
*reloc_addr = (sym == NULL ? 0 : sym->st_value) + reloc->r_addend;
break;
case R_SPARC_TLS_TPOFF32:
/* The offset is negative, forward from the thread pointer. */
/* We know the offset of object the symbol is contained in.
It is a negative value which will be added to the
thread pointer. */
if (sym != NULL)
{
CHECK_STATIC_TLS (map, sym_map);
*reloc_addr = sym->st_value - sym_map->l_tls_offset
+ reloc->r_addend;
}
break;
# ifndef RTLD_BOOTSTRAP
case R_SPARC_TLS_LE_HIX22:
case R_SPARC_TLS_LE_LOX10:
if (sym != NULL)
{
CHECK_STATIC_TLS (map, sym_map);
value = sym->st_value - sym_map->l_tls_offset
+ reloc->r_addend;
if (r_type == R_SPARC_TLS_LE_HIX22)
*reloc_addr = (*reloc_addr & 0xffc00000) | ((~value) >> 10);
else
*reloc_addr = (*reloc_addr & 0xffffe000) | (value & 0x3ff)
| 0x1c00;
}
break;
# endif
#endif
#ifndef RTLD_BOOTSTRAP
case R_SPARC_8:
*(char *) reloc_addr = value;
break;
case R_SPARC_16:
*(short *) reloc_addr = value;
break;
case R_SPARC_DISP8:
*(char *) reloc_addr = (value - (Elf32_Addr) reloc_addr);
break;
case R_SPARC_DISP16:
*(short *) reloc_addr = (value - (Elf32_Addr) reloc_addr);
break;
case R_SPARC_DISP32:
*reloc_addr = (value - (Elf32_Addr) reloc_addr);
break;
case R_SPARC_LO10:
*reloc_addr = (*reloc_addr & ~0x3ff) | (value & 0x3ff);
break;
case R_SPARC_WDISP30:
*reloc_addr = ((*reloc_addr & 0xc0000000)
| ((value - (unsigned int) reloc_addr) >> 2));
break;
case R_SPARC_HI22:
*reloc_addr = (*reloc_addr & 0xffc00000) | (value >> 10);
break;
case R_SPARC_UA16:
((unsigned char *) reloc_addr_arg) [0] = value >> 8;
((unsigned char *) reloc_addr_arg) [1] = value;
break;
case R_SPARC_UA32:
((unsigned char *) reloc_addr_arg) [0] = value >> 24;
((unsigned char *) reloc_addr_arg) [1] = value >> 16;
((unsigned char *) reloc_addr_arg) [2] = value >> 8;
((unsigned char *) reloc_addr_arg) [3] = value;
break;
#endif
#if !defined RTLD_BOOTSTRAP || defined _NDEBUG
default:
_dl_reloc_bad_type (map, r_type, 0);
break;
#endif
}
}
auto inline void
__attribute__ ((always_inline))
elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_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,
Elf32_Addr l_addr, const Elf32_Rela *reloc,
int skip_ifunc)
{
Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
if (__builtin_expect (r_type == R_SPARC_JMP_SLOT, 1))
;
else if (r_type == R_SPARC_JMP_IREL)
{
Elf32_Addr value = map->l_addr + reloc->r_addend;
if (__builtin_expect (!skip_ifunc, 1))
value = ((Elf32_Addr (*) (int)) value) (GLRO(dl_hwcap));
sparc_fixup_plt (reloc, reloc_addr, value, 1, 1);
}
else if (r_type == R_SPARC_NONE)
;
else
_dl_reloc_bad_type (map, r_type, 1);
}
#endif /* RESOLVE_MAP */
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