OpenBSD-4.6/libexec/ld.so/sparc64/rtld_machine.c
/* $OpenBSD: rtld_machine.c,v 1.43 2008/07/16 20:33:42 drahn Exp $ */
/*
* Copyright (c) 1999 Dale Rahn
* Copyright (c) 2001 Niklas Hallqvist
* Copyright (c) 2001 Artur Grabowski
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY 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.
*/
/*-
* Copyright (c) 2000 Eduardo Horvath.
* Copyright (c) 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Paul Kranenburg.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY 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.
*/
#define _DYN_LOADER
#include <sys/types.h>
#include <sys/cdefs.h>
#include <sys/mman.h>
#include <nlist.h>
#include <link.h>
#include <signal.h>
#include "syscall.h"
#include "archdep.h"
#include "resolve.h"
/*
* The following table holds for each relocation type:
* - the width in bits of the memory location the relocation
* applies to (not currently used)
* - the number of bits the relocation value must be shifted to the
* right (i.e. discard least significant bits) to fit into
* the appropriate field in the instruction word.
* - flags indicating whether
* * the relocation involves a symbol
* * the relocation is relative to the current position
* * the relocation is for a GOT entry
* * the relocation is relative to the load address
*
*/
#define _RF_S 0x80000000 /* Resolve symbol */
#define _RF_A 0x40000000 /* Use addend */
#define _RF_P 0x20000000 /* Location relative */
#define _RF_G 0x10000000 /* GOT offset */
#define _RF_B 0x08000000 /* Load address relative */
#define _RF_U 0x04000000 /* Unaligned */
#define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */
#define _RF_RS(s) ((s) & 0xff) /* right shift */
static int reloc_target_flags[] = {
0, /* NONE */
_RF_S|_RF_A| _RF_SZ(8) | _RF_RS(0), /* RELOC_8 */
_RF_S|_RF_A| _RF_SZ(16) | _RF_RS(0), /* RELOC_16 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* RELOC_32 */
_RF_S|_RF_A|_RF_P| _RF_SZ(8) | _RF_RS(0), /* DISP_8 */
_RF_S|_RF_A|_RF_P| _RF_SZ(16) | _RF_RS(0), /* DISP_16 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* DISP_32 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_30 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HI22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 13 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LO10 */
_RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT10 */
_RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT13 */
_RF_G| _RF_SZ(32) | _RF_RS(10), /* GOT22 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PC10 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC22 */
_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WPLT30 */
_RF_S| _RF_SZ(32) | _RF_RS(0), /* COPY */
_RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* GLOB_DAT */
_RF_S| _RF_SZ(32) | _RF_RS(0), /* JMP_SLOT */
_RF_A| _RF_B| _RF_SZ(64) | _RF_RS(0), /* RELATIVE */
_RF_S|_RF_A| _RF_U| _RF_SZ(32) | _RF_RS(0), /* UA_32 */
_RF_A| _RF_SZ(32) | _RF_RS(0), /* PLT32 */
_RF_A| _RF_SZ(32) | _RF_RS(10), /* HIPLT22 */
_RF_A| _RF_SZ(32) | _RF_RS(0), /* LOPLT10 */
_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT32 */
_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PCPLT22 */
_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT10 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 10 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 11 */
_RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* 64 */
_RF_S|_RF_A|/*extra*/ _RF_SZ(32) | _RF_RS(0), /* OLO10 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(42), /* HH22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(32), /* HM10 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* LM22 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(42), /* PC_HH22 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(32), /* PC_HM10 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC_LM22 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP16 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP19 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* GLOB_JMP */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 7 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 5 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 6 */
_RF_S|_RF_A|_RF_P| _RF_SZ(64) | _RF_RS(0), /* DISP64 */
_RF_A| _RF_SZ(64) | _RF_RS(0), /* PLT64 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HIX22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LOX10 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(22), /* H44 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(12), /* M44 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* L44 */
_RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* REGISTER */
_RF_S|_RF_A| _RF_U| _RF_SZ(64) | _RF_RS(0), /* UA64 */
_RF_S|_RF_A| _RF_U| _RF_SZ(16) | _RF_RS(0), /* UA16 */
};
#define RELOC_RESOLVE_SYMBOL(t) ((reloc_target_flags[t] & _RF_S) != 0)
#define RELOC_PC_RELATIVE(t) ((reloc_target_flags[t] & _RF_P) != 0)
#define RELOC_BASE_RELATIVE(t) ((reloc_target_flags[t] & _RF_B) != 0)
#define RELOC_UNALIGNED(t) ((reloc_target_flags[t] & _RF_U) != 0)
#define RELOC_USE_ADDEND(t) ((reloc_target_flags[t] & _RF_A) != 0)
#define RELOC_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff)
#define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff)
static long reloc_target_bitmask[] = {
#define _BM(x) (~(-(1ULL << (x))))
0, /* NONE */
_BM(8), _BM(16), _BM(32), /* RELOC_8, _16, _32 */
_BM(8), _BM(16), _BM(32), /* DISP8, DISP16, DISP32 */
_BM(30), _BM(22), /* WDISP30, WDISP22 */
_BM(22), _BM(22), /* HI22, _22 */
_BM(13), _BM(10), /* RELOC_13, _LO10 */
_BM(10), _BM(13), _BM(22), /* GOT10, GOT13, GOT22 */
_BM(10), _BM(22), /* _PC10, _PC22 */
_BM(30), 0, /* _WPLT30, _COPY */
-1, _BM(32), -1, /* _GLOB_DAT, JMP_SLOT, _RELATIVE */
_BM(32), _BM(32), /* _UA32, PLT32 */
_BM(22), _BM(10), /* _HIPLT22, LOPLT10 */
_BM(32), _BM(22), _BM(10), /* _PCPLT32, _PCPLT22, _PCPLT10 */
_BM(10), _BM(11), -1, /* _10, _11, _64 */
_BM(10), _BM(22), /* _OLO10, _HH22 */
_BM(10), _BM(22), /* _HM10, _LM22 */
_BM(22), _BM(10), _BM(22), /* _PC_HH22, _PC_HM10, _PC_LM22 */
_BM(16), _BM(19), /* _WDISP16, _WDISP19 */
-1, /* GLOB_JMP */
_BM(7), _BM(5), _BM(6) /* _7, _5, _6 */
-1, -1, /* DISP64, PLT64 */
_BM(22), _BM(13), /* HIX22, LOX10 */
_BM(22), _BM(10), _BM(13), /* H44, M44, L44 */
-1, -1, _BM(16), /* REGISTER, UA64, UA16 */
#undef _BM
};
#define RELOC_VALUE_BITMASK(t) (reloc_target_bitmask[t])
void _dl_reloc_plt(Elf_Word *where, Elf_Addr value, Elf_RelA *rela);
void _dl_install_plt(Elf_Word *pltgot, Elf_Addr proc);
int
_dl_md_reloc(elf_object_t *object, int rel, int relasz)
{
long i;
long numrela;
int fails = 0;
Elf_Addr loff;
Elf_RelA *relas;
struct load_list *llist;
loff = object->obj_base;
numrela = object->Dyn.info[relasz] / sizeof(Elf64_Rela);
relas = (Elf64_Rela *)(object->Dyn.info[rel]);
if (relas == NULL)
return(0);
/*
* unprotect some segments if we need it.
*/
if ((object->dyn.textrel == 1) && (rel == DT_REL || rel == DT_RELA)) {
for (llist = object->load_list; llist != NULL; llist = llist->next) {
if (!(llist->prot & PROT_WRITE))
_dl_mprotect(llist->start, llist->size,
llist->prot|PROT_WRITE);
}
}
for (i = 0; i < numrela; i++, relas++) {
Elf_Addr *where, value, ooff, mask;
Elf_Word type;
const Elf_Sym *sym, *this;
const char *symn;
type = ELF_R_TYPE(relas->r_info);
if (type == R_TYPE(NONE))
continue;
if (type == R_TYPE(JMP_SLOT) && rel != DT_JMPREL)
continue;
where = (Elf_Addr *)(relas->r_offset + loff);
if (RELOC_USE_ADDEND(type))
value = relas->r_addend;
else
value = 0;
sym = NULL;
symn = NULL;
if (RELOC_RESOLVE_SYMBOL(type)) {
sym = object->dyn.symtab;
sym += ELF_R_SYM(relas->r_info);
symn = object->dyn.strtab + sym->st_name;
if (sym->st_shndx != SHN_UNDEF &&
ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
value += loff;
} else {
this = NULL;
ooff = _dl_find_symbol_bysym(object,
ELF_R_SYM(relas->r_info), &this,
SYM_SEARCH_ALL|SYM_WARNNOTFOUND|
((type == R_TYPE(JMP_SLOT)) ?
SYM_PLT : SYM_NOTPLT),
sym, NULL);
if (this == NULL) {
resolve_failed:
if (ELF_ST_BIND(sym->st_info) !=
STB_WEAK)
fails++;
continue;
}
value += (Elf_Addr)(ooff + this->st_value);
}
}
if (type == R_TYPE(JMP_SLOT)) {
_dl_reloc_plt((Elf_Word *)where, value, relas);
continue;
}
if (type == R_TYPE(COPY)) {
void *dstaddr = where;
const void *srcaddr;
const Elf_Sym *dstsym = sym, *srcsym = NULL;
size_t size = dstsym->st_size;
Elf_Addr soff;
soff = _dl_find_symbol(symn, &srcsym,
SYM_SEARCH_OTHER|SYM_WARNNOTFOUND|SYM_NOTPLT,
dstsym, object, NULL);
if (srcsym == NULL)
goto resolve_failed;
srcaddr = (void *)(soff + srcsym->st_value);
_dl_bcopy(srcaddr, dstaddr, size);
continue;
}
if (RELOC_PC_RELATIVE(type))
value -= (Elf_Addr)where;
if (RELOC_BASE_RELATIVE(type))
value += loff;
mask = RELOC_VALUE_BITMASK(type);
value >>= RELOC_VALUE_RIGHTSHIFT(type);
value &= mask;
if (RELOC_UNALIGNED(type)) {
/* Handle unaligned relocations. */
Elf_Addr tmp = 0;
char *ptr = (char *)where;
int i, size = RELOC_TARGET_SIZE(type)/8;
/* Read it in one byte at a time. */
for (i=0; i<size; i++)
tmp = (tmp << 8) | ptr[i];
tmp &= ~mask;
tmp |= value;
/* Write it back out. */
for (i=0; i<size; i++)
ptr[i] = ((tmp >> (8*i)) & 0xff);
} else if (RELOC_TARGET_SIZE(type) > 32) {
*where &= ~mask;
*where |= value;
} else {
Elf32_Addr *where32 = (Elf32_Addr *)where;
*where32 &= ~mask;
*where32 |= value;
}
}
/* reprotect the unprotected segments */
if ((object->dyn.textrel == 1) && (rel == DT_REL || rel == DT_RELA)) {
for (llist = object->load_list; llist != NULL; llist = llist->next) {
if (!(llist->prot & PROT_WRITE))
_dl_mprotect(llist->start, llist->size,
llist->prot);
}
}
return (fails);
}
/*
* Instruction templates:
*/
#define BAA 0x10400000 /* ba,a %xcc, 0 */
#define SETHI 0x03000000 /* sethi %hi(0), %g1 */
#define JMP 0x81c06000 /* jmpl %g1+%lo(0), %g0 */
#define NOP 0x01000000 /* sethi %hi(0), %g0 */
#define OR 0x82106000 /* or %g1, 0, %g1 */
#define ORG5 0x8a116000 /* or %g5, 0, %g5 */
#define XOR 0x82186000 /* xor %g1, 0, %g1 */
#define MOV71 0x8283a000 /* or %o7, 0, %g1 */
#define MOV17 0x9c806000 /* or %g1, 0, %o7 */
#define CALL 0x40000000 /* call 0 */
#define SLLX 0x83287000 /* sllx %g1, 0, %g1 */
#define SLLXG5 0x8b297000 /* sllx %g5, 0, %g5 */
#define SRAX 0x83387000 /* srax %g1, 0, %g1 */
#define SETHIG5 0x0b000000 /* sethi %hi(0), %g5 */
#define ORG15 0x82804005 /* or %g1, %g5, %g1 */
/* %hi(v) with variable shift */
#define HIVAL(v, s) (((v) >> (s)) & 0x003fffff)
#define LOVAL(v) ((v) & 0x000003ff)
void
_dl_reloc_plt(Elf_Word *where, Elf_Addr value, Elf_RelA *rela)
{
Elf_Addr offset;
/*
* At the PLT entry pointed at by `where', we now construct
* a direct transfer to the now fully resolved function
* address.
*
* A PLT entry is supposed to start by looking like this:
*
* sethi %hi(. - .PLT0), %g1
* ba,a %xcc, .PLT1
* nop
* nop
* nop
* nop
* nop
* nop
*
* When we replace these entries we start from the second
* entry and do it in reverse order so the last thing we
* do is replace the branch. That allows us to change this
* atomically.
*
* We now need to find out how far we need to jump. We
* have a choice of several different relocation techniques
* which are increasingly expensive.
*/
offset = ((Elf_Addr)where) - value;
if (rela->r_addend) {
Elf_Addr *ptr = (Elf_Addr *)where;
/*
* This entry is >32768. Just replace the pointer.
*/
ptr[0] = value;
} else if (offset <= (1L<<20) && offset >= -(1L<<20)) {
/*
* We're within 1MB -- we can use a direct branch insn.
*
* We can generate this pattern:
*
* sethi %hi(. - .PLT0), %g1
* ba,a %xcc, addr
* nop
* nop
* nop
* nop
* nop
* nop
*
*/
where[1] = BAA | ((offset >> 2) &0x3fffff);
__asm __volatile("iflush %0+4" : : "r" (where));
} else if (value < (1UL<<32)) {
/*
* We're within 32-bits of address zero.
*
* The resulting code in the jump slot is:
*
* sethi %hi(. - .PLT0), %g1
* sethi %hi(addr), %g1
* jmp %g1+%lo(addr)
* nop
* nop
* nop
* nop
* nop
*
*/
where[2] = JMP | LOVAL(value);
where[1] = SETHI | HIVAL(value, 10);
__asm __volatile("iflush %0+8" : : "r" (where));
__asm __volatile("iflush %0+4" : : "r" (where));
} else if (value > -(1UL<<32)) {
/*
* We're within 32-bits of address -1.
*
* The resulting code in the jump slot is:
*
* sethi %hi(. - .PLT0), %g1
* sethi %hix(addr), %g1
* xor %g1, %lox(addr), %g1
* jmp %g1
* nop
* nop
* nop
* nop
*
*/
where[3] = JMP;
where[2] = XOR | ((~value) & 0x00001fff);
where[1] = SETHI | HIVAL(~value, 10);
__asm __volatile("iflush %0+12" : : "r" (where));
__asm __volatile("iflush %0+8" : : "r" (where));
__asm __volatile("iflush %0+4" : : "r" (where));
} else if (offset <= (1L<<32) && offset >= -((1L<<32) - 4)) {
/*
* We're within 32-bits -- we can use a direct call insn
*
* The resulting code in the jump slot is:
*
* sethi %hi(. - .PLT0), %g1
* mov %o7, %g1
* call (.+offset)
* mov %g1, %o7
* nop
* nop
* nop
* nop
*
*/
where[3] = MOV17;
where[2] = CALL | ((offset >> 4) & 0x3fffffff);
where[1] = MOV71;
__asm __volatile("iflush %0+12" : : "r" (where));
__asm __volatile("iflush %0+8" : : "r" (where));
__asm __volatile("iflush %0+4" : : "r" (where));
} else if (value < (1L<<42)) {
/*
* Target 42bits or smaller.
* We can generate this pattern:
*
* The resulting code in the jump slot is:
*
* sethi %hi(. - .PLT0), %g1
* sethi %hi(addr >> 20), %g1
* or %g1, %lo(addr >> 10), %g1
* sllx %g1, 10, %g1
* jmp %g1+%lo(addr)
* nop
* nop
* nop
*
* this can handle addresses 0 - 0x3fffffffffc
*/
where[4] = JMP | LOVAL(value);
where[3] = SLLX | 10;
where[2] = OR | LOVAL(value >> 10);
where[1] = SETHI | HIVAL(value, 20);
__asm __volatile("iflush %0+16" : : "r" (where));
__asm __volatile("iflush %0+12" : : "r" (where));
__asm __volatile("iflush %0+8" : : "r" (where));
__asm __volatile("iflush %0+4" : : "r" (where));
} else if (value > -(1UL<<41)) {
/*
* Large target >= 0xfffffe0000000000UL
* We can generate this pattern:
*
* The resulting code in the jump slot is:
*
* sethi %hi(. - .PLT0), %g1
* sethi %hi(addr >> 20), %g1
* or %g1, %lo(addr >> 10), %g1
* sllx %g1, 32, %g1
* srax %g1, 22, %g1
* jmp %g1+%lo(addr)
* nop
* nop
* nop
*
*/
where[5] = JMP | LOVAL(value);
where[4] = SRAX | 22;
where[3] = SLLX | 32;
where[2] = OR | LOVAL(value >> 10);
where[1] = SETHI | HIVAL(value, 20);
__asm __volatile("iflush %0+16" : : "r" (where));
__asm __volatile("iflush %0+12" : : "r" (where));
__asm __volatile("iflush %0+8" : : "r" (where));
__asm __volatile("iflush %0+4" : : "r" (where));
} else {
/*
* We need to load all 64-bits
*
* The resulting code in the jump slot is:
*
* sethi %hi(. - .PLT0), %g1
* sethi %hi(addr >> 42), %g5
* sethi %hi(addr >> 10), %g1
* or %g1, %lo(addr >> 32), %g5
* sllx %g5, 32, %g5
* or %g1, %g5, %g1
* jmp %g1+%lo(addr)
* nop
*
*/
where[6] = JMP | LOVAL(value);
where[5] = ORG15;
where[4] = SLLXG5 | 32;
where[3] = ORG5 | LOVAL(value >> 32);
where[2] = SETHI | HIVAL(value, 10);
where[1] = SETHIG5 | HIVAL(value, 42);
__asm __volatile("iflush %0+24" : : "r" (where));
__asm __volatile("iflush %0+20" : : "r" (where));
__asm __volatile("iflush %0+16" : : "r" (where));
__asm __volatile("iflush %0+12" : : "r" (where));
__asm __volatile("iflush %0+8" : : "r" (where));
__asm __volatile("iflush %0+4" : : "r" (where));
}
}
/*
* Resolve a symbol at run-time.
*/
Elf_Addr
_dl_bind(elf_object_t *object, int index)
{
Elf_RelA *rela;
Elf_Word *addr;
Elf_Addr ooff;
const Elf_Sym *sym, *this;
const char *symn;
sigset_t omask, nmask;
rela = (Elf_RelA *)(object->Dyn.info[DT_JMPREL]);
if (ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)) {
/*
* XXXX
*
* The first four PLT entries are reserved. There
* is some disagreement whether they should have
* associated relocation entries. Both the SPARC
* 32-bit and 64-bit ELF specifications say that
* they should have relocation entries, but the
* 32-bit SPARC binutils do not generate them,
* and now the 64-bit SPARC binutils have stopped
* generating them too.
*
* So, to provide binary compatibility, we will
* check the first entry, if it is reserved it
* should not be of the type JMP_SLOT. If it
* is JMP_SLOT, then the 4 reserved entries were
* not generated and our index is 4 entries too far.
*/
index -= 4;
}
rela += index;
sym = object->dyn.symtab;
sym += ELF64_R_SYM(rela->r_info);
symn = object->dyn.strtab + sym->st_name;
addr = (Elf_Word *)(object->obj_base + rela->r_offset);
this = NULL;
ooff = _dl_find_symbol(symn, &this,
SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_PLT, sym,
object, NULL);
if (this == NULL) {
_dl_printf("lazy binding failed!\n");
*((int *)0) = 0; /* XXX */
}
/* if PLT is protected, allow the write */
if (object->plt_size != 0) {
sigfillset(&nmask);
_dl_sigprocmask(SIG_BLOCK, &nmask, &omask);
_dl_thread_bind_lock(0);
_dl_mprotect((void*)object->plt_start, object->plt_size,
PROT_READ|PROT_WRITE|PROT_EXEC);
}
_dl_reloc_plt(addr, ooff + this->st_value, rela);
/* if PLT is (to be protected), change back to RO/X */
if (object->plt_size != 0) {
_dl_mprotect((void*)object->plt_start, object->plt_size,
PROT_READ|PROT_EXEC);
_dl_thread_bind_lock(1);
_dl_sigprocmask(SIG_SETMASK, &omask, NULL);
}
return ooff + this->st_value;
}
/*
* Install rtld function call into this PLT slot.
*/
#define SAVE 0x9de3bf50
#define SETHI_l0 0x21000000
#define SETHI_l1 0x23000000
#define OR_l0_l0 0xa0142000
#define SLLX_l0_32_l0 0xa12c3020
#define OR_l0_l1_l0 0xa0140011
#define JMPL_l0_o1 0x93c42000
#define MOV_g1_o0 0x90100001
void
_dl_install_plt(Elf_Word *pltgot, Elf_Addr proc)
{
pltgot[0] = SAVE;
pltgot[1] = SETHI_l0 | HIVAL(proc, 42);
pltgot[2] = SETHI_l1 | HIVAL(proc, 10);
pltgot[3] = OR_l0_l0 | LOVAL((proc) >> 32);
pltgot[4] = SLLX_l0_32_l0;
pltgot[5] = OR_l0_l1_l0;
pltgot[6] = JMPL_l0_o1 | LOVAL(proc);
pltgot[7] = MOV_g1_o0;
}
void _dl_bind_start_0(long, long);
void _dl_bind_start_1(long, long);
/*
* Relocate the Global Offset Table (GOT).
*/
int
_dl_md_reloc_got(elf_object_t *object, int lazy)
{
int fails = 0;
Elf_Addr *pltgot = (Elf_Addr *)object->Dyn.info[DT_PLTGOT];
Elf_Word *entry = (Elf_Word *)pltgot;
Elf_Addr ooff;
Elf_Addr plt_addr;
const Elf_Sym *this;
if (object->Dyn.info[DT_PLTREL] != DT_RELA)
return (0);
object->got_addr = NULL;
object->got_size = 0;
this = NULL;
ooff = _dl_find_symbol("__got_start", &this,
SYM_SEARCH_OBJ|SYM_NOWARNNOTFOUND|SYM_PLT, NULL,
object, NULL);
if (this != NULL)
object->got_addr = ooff + this->st_value;
this = NULL;
ooff = _dl_find_symbol("__got_end", &this,
SYM_SEARCH_OBJ|SYM_NOWARNNOTFOUND|SYM_PLT, NULL,
object, NULL);
if (this != NULL)
object->got_size = ooff + this->st_value - object->got_addr;
plt_addr = 0;
object->plt_size = 0;
this = NULL;
ooff = _dl_find_symbol("__plt_start", &this,
SYM_SEARCH_OBJ|SYM_NOWARNNOTFOUND|SYM_PLT, NULL,
object, NULL);
if (this != NULL)
plt_addr = ooff + this->st_value;
this = NULL;
ooff = _dl_find_symbol("__plt_end", &this,
SYM_SEARCH_OBJ|SYM_NOWARNNOTFOUND|SYM_PLT, NULL,
object, NULL);
if (this != NULL)
object->plt_size = ooff + this->st_value - plt_addr;
if (object->got_addr == NULL)
object->got_start = NULL;
else {
object->got_start = ELF_TRUNC(object->got_addr, _dl_pagesz);
object->got_size += object->got_addr - object->got_start;
object->got_size = ELF_ROUND(object->got_size, _dl_pagesz);
}
if (plt_addr == NULL)
object->plt_start = NULL;
else {
object->plt_start = ELF_TRUNC(plt_addr, _dl_pagesz);
object->plt_size += plt_addr - object->plt_start;
object->plt_size = ELF_ROUND(object->plt_size, _dl_pagesz);
}
if (!lazy) {
fails = _dl_md_reloc(object, DT_JMPREL, DT_PLTRELSZ);
} else {
_dl_install_plt(&entry[0], (Elf_Addr)&_dl_bind_start_0);
_dl_install_plt(&entry[8], (Elf_Addr)&_dl_bind_start_1);
pltgot[8] = (Elf_Addr)object;
}
if (object->got_size != 0)
_dl_mprotect((void*)object->got_start, object->got_size,
PROT_READ);
if (object->plt_size != 0)
_dl_mprotect((void*)object->plt_start, object->plt_size,
PROT_READ|PROT_EXEC);
return (fails);
}