Updated rtld for n32 support.

Submitted by:	jmallet@
Obtained from:	NetBSD
This commit is contained in:
imp 2010-03-04 04:53:05 +00:00
parent 4c7cffa4b9
commit 2c774f7ff2
2 changed files with 313 additions and 151 deletions

View File

@ -1,5 +1,4 @@
/* $NetBSD: mdreloc.c,v 1.23 2003/07/26 15:04:38 mrg Exp $ */
/* $NetBSD: mips_reloc.c,v 1.53 2008/07/24 04:39:25 matt Exp $ */
/* $NetBSD: mips_reloc.c,v 1.58 2010/01/14 11:57:06 skrll Exp $ */
/*
* Copyright 1997 Michael L. Hitch <mhitch@montana.edu>
@ -31,14 +30,14 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/mman.h>
#include <errno.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/endian.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "debug.h"
#include "rtld.h"
@ -47,6 +46,7 @@ init_pltgot(Obj_Entry *obj)
{
if (obj->pltgot != NULL) {
obj->pltgot[0] = (Elf_Addr) &_rtld_bind_start;
/* XXX only if obj->pltgot[1] & 0x80000000 ?? */
obj->pltgot[1] |= (Elf_Addr) obj;
}
}
@ -58,39 +58,74 @@ do_copy_relocations(Obj_Entry *dstobj)
return 0;
}
void _rtld_bind_start(void);
void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
int open();
int _open();
/*
* It is possible for the compiler to emit relocations for unaligned data.
* We handle this situation with these inlines.
*/
#define RELOC_ALIGNED_P(x) \
(((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
#if ELFSIZE == 64
/*
* ELF64 MIPS encodes the relocs uniquely. The first 32-bits of info contain
* the symbol index. The top 32-bits contain three relocation types encoded
* in big-endian integer with first relocation in LSB. This means for little
* endian we have to byte swap that interger (r_type).
*/
#define Elf_Sxword Elf64_Sxword
#define ELF_R_NXTTYPE_64_P(r_type) ((((r_type) >> 8) & 0xff) == R_TYPE(64))
#if BYTE_ORDER == LITTLE_ENDIAN
#undef ELF_R_SYM
#undef ELF_R_TYPE
#define ELF_R_SYM(r_info) ((r_info) & 0xffffffff)
#define ELF_R_TYPE(r_info) bswap32((r_info) >> 32)
#endif
#else
#define ELF_R_NXTTYPE_64_P(r_type) (0)
#define Elf_Sxword Elf32_Sword
#endif
static __inline Elf_Addr
load_ptr(void *where)
static __inline Elf_Sxword
load_ptr(void *where, size_t len)
{
if (__predict_true(RELOC_ALIGNED_P(where)))
return *(Elf_Addr *)where;
else {
Elf_Addr res;
Elf_Sxword val;
(void)memcpy(&res, where, sizeof(res));
return res;
if (__predict_true(((uintptr_t)where & (len - 1)) == 0)) {
#if ELFSIZE == 64
if (len == sizeof(Elf_Sxword))
return *(Elf_Sxword *)where;
#endif
return *(Elf_Sword *)where;
}
val = 0;
#if BYTE_ORDER == LITTLE_ENDIAN
(void)memcpy(&val, where, len);
#endif
#if BYTE_ORDER == BIG_ENDIAN
(void)memcpy((uint8_t *)((&val)+1) - len, where, len);
#endif
return (len == sizeof(Elf_Sxword)) ? val : (Elf_Sword)val;
}
static __inline void
store_ptr(void *where, Elf_Addr val)
store_ptr(void *where, Elf_Sxword val, size_t len)
{
if (__predict_true(RELOC_ALIGNED_P(where)))
*(Elf_Addr *)where = val;
else
(void)memcpy(where, &val, sizeof(val));
if (__predict_true(((uintptr_t)where & (len - 1)) == 0)) {
#if ELFSIZE == 64
if (len == sizeof(Elf_Sxword)) {
*(Elf_Sxword *)where = val;
return;
}
#endif
*(Elf_Sword *)where = val;
return;
}
#if BYTE_ORDER == LITTLE_ENDIAN
(void)memcpy(where, &val, len);
#endif
#if BYTE_ORDER == BIG_ENDIAN
(void)memcpy(where, (const uint8_t *)((&val)+1) - len, len);
#endif
}
void
@ -102,7 +137,7 @@ _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
Elf_Addr *where;
Elf_Addr *got = NULL;
Elf_Word local_gotno = 0, symtabno = 0, gotsym = 0;
int i;
size_t i;
for (; dynp->d_tag != DT_NULL; dynp++) {
switch (dynp->d_tag) {
@ -147,18 +182,40 @@ _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
rellim = (const Elf_Rel *)((caddr_t)rel + relsz);
for (; rel < rellim; rel++) {
Elf_Word r_symndx, r_type;
where = (void *)(relocbase + rel->r_offset);
switch (ELF_R_TYPE(rel->r_info)) {
r_symndx = ELF_R_SYM(rel->r_info);
r_type = ELF_R_TYPE(rel->r_info);
switch (r_type & 0xff) {
case R_TYPE(REL32): {
const size_t rlen =
ELF_R_NXTTYPE_64_P(r_type)
? sizeof(Elf_Sxword)
: sizeof(Elf_Sword);
Elf_Sxword old = load_ptr(where, rlen);
Elf_Sxword val = old;
#if ELFSIZE == 64
assert(r_type == R_TYPE(REL32)
|| r_type == (R_TYPE(REL32)|(R_TYPE(64) << 8)));
#endif
assert(r_symndx < gotsym);
sym = symtab + r_symndx;
assert(ELF_ST_BIND(sym->st_info) == STB_LOCAL);
val += relocbase;
store_ptr(where, val, sizeof(Elf_Sword));
dbg("REL32/L(%p) %p -> %p in <self>",
where, (void *)old, (void *)val);
store_ptr(where, val, rlen);
break;
}
case R_TYPE(GPREL32):
case R_TYPE(NONE):
break;
case R_TYPE(REL32):
assert(ELF_R_SYM(rel->r_info) < gotsym);
sym = symtab + ELF_R_SYM(rel->r_info);
assert(ELF_ST_BIND(sym->st_info) == STB_LOCAL);
store_ptr(where, load_ptr(where) + relocbase);
break;
default:
abort();
@ -189,9 +246,6 @@ _mips_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
return (Elf_Addr)target;
}
/*
* Process non-PLT relocations
*/
int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
{
@ -200,12 +254,24 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
Elf_Addr *got = obj->pltgot;
const Elf_Sym *sym, *def;
const Obj_Entry *defobj;
int i;
Elf_Word i;
#ifdef SUPPORT_OLD_BROKEN_LD
int broken;
#endif
/* The relocation for the dynamic loader has already been done. */
if (obj == obj_rtld)
return (0);
#ifdef SUPPORT_OLD_BROKEN_LD
broken = 0;
sym = obj->symtab;
for (i = 1; i < 12; i++)
if (sym[i].st_info == ELF_ST_INFO(STB_LOCAL, STT_NOTYPE))
broken = 1;
dbg("%s: broken=%d", obj->path, broken);
#endif
i = (got[1] & 0x80000000) ? 2 : 1;
/* Relocate the local GOT entries */
@ -218,11 +284,34 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
}
sym = obj->symtab + obj->gotsym;
dbg("got:%p for %d entries",
got, obj->symtabno);
/* Now do the global GOT entries */
for (i = obj->gotsym; i < obj->symtabno; i++) {
dbg(" doing got %d sym %p (%s, %lx)", i - obj->gotsym, sym,
sym->st_name + obj->strtab, (u_long) *got);
#ifdef SUPPORT_OLD_BROKEN_LD
if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
broken && sym->st_shndx == SHN_UNDEF) {
/*
* XXX DANGER WILL ROBINSON!
* You might think this is stupid, as it intentionally
* defeats lazy binding -- and you'd be right.
* Unfortunately, for lazy binding to work right, we
* need to a way to force the GOT slots used for
* function pointers to be resolved immediately. This
* is supposed to be done automatically by the linker,
* by not outputting a PLT slot and setting st_value
* to 0 if there are non-PLT references, but older
* versions of GNU ld do not do this.
*/
def = find_symdef(i, obj, &defobj, false, NULL);
if (def == NULL)
return -1;
*got = def->st_value + (Elf_Addr)defobj->relocbase;
} else
#endif
if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
sym->st_value != 0 && sym->st_shndx == SHN_UNDEF) {
/*
@ -273,50 +362,87 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
defobj, defobj->path);
}
}
dbg(" --> now %lx", (u_long) *got);
++sym;
++got;
}
got = obj->pltgot;
rellim = (const Elf_Rel *)((caddr_t)obj->rel + obj->relsize);
for (rel = obj->rel; rel < rellim; rel++) {
Elf_Word r_symndx, r_type;
void *where;
Elf_Addr tmp;
unsigned long symnum;
where = obj->relocbase + rel->r_offset;
symnum = ELF_R_SYM(rel->r_info);
switch (ELF_R_TYPE(rel->r_info)) {
r_symndx = ELF_R_SYM(rel->r_info);
r_type = ELF_R_TYPE(rel->r_info);
switch (r_type & 0xff) {
case R_TYPE(NONE):
break;
case R_TYPE(REL32):
case R_TYPE(REL32): {
/* 32-bit PC-relative reference */
def = obj->symtab + symnum;
if (symnum >= obj->gotsym) {
tmp = load_ptr(where);
tmp += got[obj->local_gotno + symnum - obj->gotsym];
store_ptr(where, tmp);
break;
const size_t rlen =
ELF_R_NXTTYPE_64_P(r_type)
? sizeof(Elf_Sxword)
: sizeof(Elf_Sword);
Elf_Sxword old = load_ptr(where, rlen);
Elf_Sxword val = old;
def = obj->symtab + r_symndx;
if (r_symndx >= obj->gotsym) {
val += got[obj->local_gotno + r_symndx - obj->gotsym];
dbg("REL32/G(%p) %p --> %p (%s) in %s",
where, (void *)old, (void *)val,
obj->strtab + def->st_name,
obj->path);
} else {
tmp = load_ptr(where);
/*
* XXX: ABI DIFFERENCE!
*
* Old NetBSD binutils would generate shared
* libs with section-relative relocations being
* already adjusted for the start address of
* the section.
*
* New binutils, OTOH, generate shared libs
* with the same relocations being based at
* zero, so we need to add in the start address
* of the section.
*
* --rkb, Oct 6, 2001
*/
if (def->st_info ==
ELF_ST_INFO(STB_LOCAL, STT_SECTION)
#ifdef SUPPORT_OLD_BROKEN_LD
&& !broken
#endif
)
tmp += (Elf_Addr)def->st_value;
val += (Elf_Addr)def->st_value;
tmp += (Elf_Addr)obj->relocbase;
store_ptr(where, tmp);
val += (Elf_Addr)obj->relocbase;
dbg("REL32/L(%p) %p -> %p (%s) in %s",
where, (void *)old, (void *)val,
obj->strtab + def->st_name, obj->path);
}
store_ptr(where, val, rlen);
break;
}
default:
dbg("sym = %lu, type = %lu, offset = %p, "
"contents = %p, symbol = %s",
symnum, (u_long)ELF_R_TYPE(rel->r_info),
(void *)rel->r_offset, (void *)load_ptr(where),
obj->strtab + obj->symtab[symnum].st_name);
(u_long)r_symndx, (u_long)ELF_R_TYPE(rel->r_info),
(void *)rel->r_offset,
(void *)load_ptr(where, sizeof(Elf_Sword)),
obj->strtab + obj->symtab[r_symndx].st_name);
_rtld_error("%s: Unsupported relocation type %ld "
"in non-PLT relocations\n",
"in non-PLT relocations",
obj->path, (u_long) ELF_R_TYPE(rel->r_info));
return -1;
}
@ -331,6 +457,7 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
int
reloc_plt(Obj_Entry *obj)
{
#if 0
const Elf_Rel *rellim;
const Elf_Rel *rel;
@ -345,6 +472,8 @@ reloc_plt(Obj_Entry *obj)
*where += (Elf_Addr )obj->relocbase;
}
#endif
/* PLT fixups were done above in the GOT relocation. */
return (0);
}

View File

@ -1,5 +1,4 @@
/* $NetBSD: rtld_start.S,v 1.9 2002/10/05 11:59:05 mycroft Exp $ */
/* $FreeBSD$ */
/* $NetBSD: rtld_start.S,v 1.10 2009/12/14 00:41:19 matt Exp $ */
/*
* Copyright 1997 Michael L. Hitch <mhitch@montana.edu>
@ -27,6 +26,8 @@
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <machine/asm.h>
@ -34,94 +35,126 @@
.globl _C_LABEL(_rtld_relocate_nonplt_self)
.globl _C_LABEL(_rtld)
#define PTR_SIZE (1<<PTR_SCALESHIFT)
/*
* a0 stack pointer
* a1 rtld cleanup (filled in by dynamic loader)
* a2 rtld object (filled in by dynamic loader)
* a3 ps_strings
*/
LEAF(rtld_start)
.abicalls
.frame sp, 4*PTR_SIZE, ra
.mask 0x10090000,-PTR_SIZE
.set noreorder
.cpload t9
addu sp, sp, -16 /* adjust stack pointer */
/* keep it aligned */
.cprestore 0 /* -> 0(sp) for gp */
/* -> 4(sp) for atexit */
/* -> 8(sp) for obj_main */
SETUP_GP
PTR_SUBU sp, 4*PTR_SIZE /* adjust stack pointer */
SETUP_GP64(s4, rtld_start)
SAVE_GP(0)
/* -> 1*PTR_SIZE(sp) for atexit */
/* -> 2*PTR_SIZE(sp) for obj_main */
move s0, a0 /* save stack pointer from a0 */
move s1,a3 /* save ps_strings pointer */
move s3, a3 /* save ps_strings pointer */
la a1, 1f
PTR_LA a1, 1f
bal 1f
PTR_LA t0, _C_LABEL(_rtld_relocate_nonplt_self)
1: PTR_SUBU a1, ra, a1 /* relocbase */
PTR_LA a0, _DYNAMIC
PTR_ADDU t9, a1, t0
jalr t9 /* _rtld_relocate_nonplt_self(dynp, relocabase) */
PTR_ADDU a0, a1, a0 /* &_DYNAMIC */
move a0, s0 /* sp */
PTR_ADDU a1, sp, 2*PTR_SIZE /* &our atexit function */
PTR_ADDU a2, sp, 3*PTR_SIZE /* obj_main entry */
jal _C_LABEL(_rtld) /* v0 = _rtld(sp, cleanup, objp) */
nop
1: subu a1, ra, a1 /* relocbase */
la t9,_C_LABEL(_rtld_relocate_nonplt_self)
move s2,a1
la a0,_DYNAMIC
addu t9, a1, t9
jalr t9
addu a0, a1, a0 /* &_DYNAMIC */
PTR_L a1, 2*PTR_SIZE(sp) /* our atexit function */
PTR_L a2, 3*PTR_SIZE(sp) /* obj_main entry */
PTR_ADDU sp, 4*PTR_SIZE /* readjust stack */
move a0, s0 /* stack pointer */
addu a1, sp, 4 /* &exit_proc */
addu a2, sp, 8 /* &objp */
addu sp, sp, -16 /* arguments slot */
jal _C_LABEL(_rtld) /* v0 = _rtld(sp, exit_proc, objp) */
nop
addu sp, sp, 16
move a0, s0 /* arguments pointer */
move a3, s1 /* arguments pointer */
lw a1, 4(sp) /* our atexit function */
lw a2, 8(sp) /* obj_main entry */
addu sp, sp, 16 /* readjust stack */
move t9, v0
move a2,s1 /* restore ps_strings */
jr t9 /* _start(ap, cleanup, obj, ps_strings); */
nop
jr t9 /* _start(sp, cleanup, obj); */
move a3, s3 /* restore ps_strings */
END(rtld_start)
#define XCALLFRAME_SIZ (12*SZREG)
#define XCALLFRAME_RA (10*SZREG)
#define XCALLFRAME_GP (9*SZREG)
#define XCALLFRAME_S0 (8*SZREG)
#define XCALLFRAME_A3 (7*SZREG)
#define XCALLFRAME_A2 (6*SZREG)
#define XCALLFRAME_A1 (5*SZREG)
#define XCALLFRAME_A0 (4*SZREG)
#if defined(__mips_n32) || defined(__mips_n64)
#define XCALLFRAME_A7 (3*SZREG)
#define XCALLFRAME_A6 (2*SZREG)
#define XCALLFRAME_A5 (1*SZREG)
#define XCALLFRAME_A4 (0*SZREG)
#endif
.globl _rtld_bind_start
.ent _rtld_bind_start
_rtld_bind_start:
/* ABI conventions for stubs:
* t8 contains symbol index
* t7 contains return address
*/
.frame sp, 0, ra /* satisfy compiler */
.frame sp, XCALLFRAME_SIZ, $15
move v1, gp /* save old GP */
add t9,8 /* modify T9 to point at .cpload */
.cpload t9
subu sp,48 /* save arguments and sp value */
.cprestore 36
sw a0,16(sp)
sw a1,20(sp)
sw a2,24(sp)
sw a3,28(sp)
sw s0,32(sp)
sw t7,40(sp)
#if defined(__mips_o32) || defined(__mips_o64)
PTR_ADDU t9, 8 /* modify T9 to point at .cpload */
#endif
SETUP_GP
PTR_SUBU sp, XCALLFRAME_SIZ /* save arguments and sp value in stack */
SETUP_GP64(XCALLFRAME_GP, _rtld_bind_start)
SAVE_GP(XCALLFRAME_GP)
#if defined(__mips_n32) || defined(__mips_n64)
REG_S a4, XCALLFRAME_A4(sp)
REG_S a5, XCALLFRAME_A5(sp)
REG_S a6, XCALLFRAME_A6(sp)
REG_S a7, XCALLFRAME_A7(sp)
#endif
REG_S a0, XCALLFRAME_A0(sp)
REG_S a1, XCALLFRAME_A1(sp)
REG_S a2, XCALLFRAME_A2(sp)
REG_S a3, XCALLFRAME_A3(sp)
REG_S $15, XCALLFRAME_RA(sp) /* ra is in t7/t3 */
REG_S s0, XCALLFRAME_S0(sp)
move s0, sp
move a0, v1 /* old GP */
subu a0, a0, 0x7ff0 /* The offset of $gp from the */
/* beginning of the .got section: */
/* $gp = .got + 0x7ff0, so */
/* .got = $gp - 0x7ff0 */
/* Simple math as you can see. */
#if defined(__mips_n64)
ld a0, 8(a0) /* object = pltgot[1] & 0x7fffffff */
#else
lw a0, 4(a0) /* object = pltgot[1] & 0x7fffffff */
#endif
and a0, a0, 0x7fffffff
move a1, t8 /* symbol index */
jal _C_LABEL(_mips_rtld_bind)
nop
move sp, s0
lw ra,40(sp)
lw a0,16(sp)
lw a1,20(sp)
lw a2,24(sp)
lw a3,28(sp)
lw s0,32(sp)
addu sp,48
REG_L ra, XCALLFRAME_RA(sp)
REG_L s0, XCALLFRAME_S0(sp)
REG_L a0, XCALLFRAME_A0(sp)
REG_L a1, XCALLFRAME_A1(sp)
REG_L a2, XCALLFRAME_A2(sp)
REG_L a3, XCALLFRAME_A3(sp)
#if defined(__mips_n32) || defined(__mips_n64)
REG_L a4, XCALLFRAME_A4(sp)
REG_L a5, XCALLFRAME_A5(sp)
REG_L a6, XCALLFRAME_A6(sp)
REG_L a7, XCALLFRAME_A7(sp)
#endif
RESTORE_GP64
PTR_ADDU sp, XCALLFRAME_SIZ
move t9, v0
jr t9
nop
.end _rtld_bind_start
END(_rtld_bind_start)