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freebsd-skq/libexec/rtld-elf/sparc64/reloc.c
Alexander Kabaev 605f36fc1e No need to zero fill memory, mmapped anonymously. Kernel will 
return pre-zeroed pages itself.

Noticed by:     jake
2003-03-14 21:10:13 +00:00

720 lines
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/* $NetBSD: mdreloc.c,v 1.5 2001/04/25 12:24:51 kleink Exp $ */
/*-
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/mman.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "debug.h"
#include "rtld.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_SZ(32) | _RF_RS(0), /* COPY */
_RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* GLOB_DAT */
_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 */
};
#if 0
static const char *reloc_names[] = {
"NONE", "RELOC_8", "RELOC_16", "RELOC_32", "DISP_8",
"DISP_16", "DISP_32", "WDISP_30", "WDISP_22", "HI22",
"22", "13", "LO10", "GOT10", "GOT13",
"GOT22", "PC10", "PC22", "WPLT30", "COPY",
"GLOB_DAT", "JMP_SLOT", "RELATIVE", "UA_32", "PLT32",
"HIPLT22", "LOPLT10", "LOPLT10", "PCPLT22", "PCPLT32",
"10", "11", "64", "OLO10", "HH22",
"HM10", "LM22", "PC_HH22", "PC_HM10", "PC_LM22",
"WDISP16", "WDISP19", "GLOB_JMP", "7", "5", "6",
"DISP64", "PLT64", "HIX22", "LOX10", "H44", "M44",
"L44", "REGISTER", "UA64", "UA16"
};
#endif
#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 */
_BM(32), _BM(32), _BM(32), /* _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])
#undef flush
#define flush(va, offs) \
__asm __volatile("flush %0 + %1" : : "r" (va), "I" (offs));
static int reloc_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela,
SymCache *cache);
static void install_plt(Elf_Half *pltgot, Elf_Addr proc);
extern char _rtld_bind_start_0[];
extern char _rtld_bind_start_1[];
int
do_copy_relocations(Obj_Entry *dstobj)
{
const Elf_Rela *relalim;
const Elf_Rela *rela;
const Elf_Sym *dstsym;
const Elf_Sym *srcsym;
void *dstaddr;
const void *srcaddr;
Obj_Entry *srcobj;
unsigned long hash;
const char *name;
size_t size;
assert(dstobj->mainprog); /* COPY relocations are invalid elsewhere */
relalim = (const Elf_Rela *)((caddr_t)dstobj->rela + dstobj->relasize);
for (rela = dstobj->rela; rela < relalim; rela++) {
if (ELF_R_TYPE(rela->r_info) == R_SPARC_COPY) {
dstaddr = (void *)(dstobj->relocbase + rela->r_offset);
dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info);
name = dstobj->strtab + dstsym->st_name;
hash = elf_hash(name);
size = dstsym->st_size;
for (srcobj = dstobj->next; srcobj != NULL;
srcobj = srcobj->next)
if ((srcsym = symlook_obj(name, hash, srcobj,
false)) != NULL)
break;
if (srcobj == NULL) {
_rtld_error("Undefined symbol \"%s\""
"referenced from COPY relocation"
"in %s", name, dstobj->path);
return (-1);
}
srcaddr = (const void *)(srcobj->relocbase +
srcsym->st_value);
memcpy(dstaddr, srcaddr, size);
}
}
return (0);
}
int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
{
const Elf_Rela *relalim;
const Elf_Rela *rela;
SymCache *cache;
int bytes = obj->nchains * sizeof(SymCache);
int r = -1;
/*
* The dynamic loader may be called from a thread, we have
* limited amounts of stack available so we cannot use alloca().
*/
cache = mmap(NULL, bytes, PROT_READ|PROT_WRITE, MAP_ANON, -1, 0);
if (cache == MAP_FAILED)
cache = NULL;
relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize);
for (rela = obj->rela; rela < relalim; rela++) {
if (reloc_nonplt_object(obj, rela, cache) < 0)
goto done;
}
r = 0;
done:
if (cache)
munmap(cache, bytes);
return (r);
}
static int
reloc_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela, SymCache *cache)
{
const Obj_Entry *defobj;
const Elf_Sym *def;
Elf_Addr *where;
Elf_Half *where32;
Elf_Word type;
Elf_Addr value;
Elf_Addr mask;
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
where32 = (Elf_Half *)where;
defobj = NULL;
def = NULL;
type = ELF_R_TYPE(rela->r_info);
if (type == R_SPARC_NONE)
return (0);
/* We do JMP_SLOTs below */
if (type == R_SPARC_JMP_SLOT)
return (0);
/* COPY relocs are also handled elsewhere */
if (type == R_SPARC_COPY)
return (0);
/*
* Note: R_SPARC_UA16 must be numerically largest relocation type.
*/
if (type > R_SPARC_UA16)
return (-1);
value = rela->r_addend;
/*
* Handle relative relocs here, because we might not
* be able to access globals yet.
*/
if (type == R_SPARC_RELATIVE) {
/* XXXX -- apparently we ignore the preexisting value */
*where = (Elf_Addr)(obj->relocbase + value);
return (0);
}
/*
* If we get here while relocating rtld itself, we will crash because
* a non-local variable is accessed.
*/
if (RELOC_RESOLVE_SYMBOL(type)) {
/* Find the symbol */
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
false, cache);
if (def == NULL)
return (-1);
/* Add in the symbol's absolute address */
value += (Elf_Addr)(defobj->relocbase + def->st_value);
}
if (RELOC_PC_RELATIVE(type))
value -= (Elf_Addr)where;
if (RELOC_BASE_RELATIVE(type)) {
/*
* Note that even though sparcs use `Elf_rela' exclusively
* we still need the implicit memory addend in relocations
* referring to GOT entries. Undoubtedly, someone f*cked
* this up in the distant past, and now we're stuck with
* it in the name of compatibility for all eternity..
*
* In any case, the implicit and explicit should be mutually
* exclusive. We provide a check for that here.
*/
/* XXXX -- apparently we ignore the preexisting value */
value += (Elf_Addr)(obj->relocbase);
}
mask = RELOC_VALUE_BITMASK(type);
value >>= RELOC_VALUE_RIGHTSHIFT(type);
value &= mask;
if (RELOC_UNALIGNED(type)) {
/* Handle unaligned relocations. */
Elf_Addr tmp;
char *ptr;
int size;
int i;
size = RELOC_TARGET_SIZE(type) / 8;
ptr = (char *)where;
tmp = 0;
/* 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 >> ((size - i - 1) * 8)) & 0xff);
} else if (RELOC_TARGET_SIZE(type) > 32) {
*where &= ~mask;
*where |= value;
} else {
*where32 &= ~mask;
*where32 |= value;
}
return (0);
}
int
reloc_plt(Obj_Entry *obj)
{
#if 0
const Obj_Entry *defobj;
const Elf_Rela *relalim;
const Elf_Rela *rela;
const Elf_Sym *def;
Elf_Addr *where;
Elf_Addr value;
relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
for (rela = obj->pltrela; rela < relalim; rela++) {
if (rela->r_addend == 0)
continue;
assert(ELF_R_TYPE(rela->r_info) == R_SPARC_JMP_SLOT);
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
true, NULL);
value = (Elf_Addr)(defobj->relocbase + def->st_value);
*where = value;
}
#endif
return (0);
}
/*
* 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 0x82806000 /* or %g1, 0, %g1 */
#define XOR 0x82c06000 /* 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 0x8b407000 /* sllx %g1, 0, %g1 */
#define SETHIG5 0x0b000000 /* sethi %hi(0), %g5 */
#define ORG5 0x82804005 /* or %g1, %g5, %g1 */
/* %hi(v) with variable shift */
#define HIVAL(v, s) (((v) >> (s)) & 0x003fffff)
#define LOVAL(v) ((v) & 0x000003ff)
int
reloc_jmpslots(Obj_Entry *obj)
{
const Obj_Entry *defobj;
const Elf_Rela *relalim;
const Elf_Rela *rela;
const Elf_Sym *def;
Elf_Addr *where;
Elf_Addr target;
relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
for (rela = obj->pltrela; rela < relalim; rela++) {
assert(ELF_R_TYPE(rela->r_info) == R_SPARC_JMP_SLOT);
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
true, NULL);
if (def == NULL)
return -1;
target = (Elf_Addr)(defobj->relocbase + def->st_value);
reloc_jmpslot(where, target, defobj, obj, (Elf_Rel *)rela);
}
obj->jmpslots_done = true;
return (0);
}
Elf_Addr
reloc_jmpslot(Elf_Addr *wherep, Elf_Addr target, const Obj_Entry *obj,
const Obj_Entry *refobj, const Elf_Rel *rel)
{
const Elf_Rela *rela = (const Elf_Rela *)rel;
Elf_Addr offset;
Elf_Half *where;
if (rela - refobj->pltrela < 32764) {
/*
* 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 (. - .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.
*/
where = (Elf_Half *)wherep;
offset = ((Elf_Addr)where) - target;
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);
flush(where, 4);
} else if (target >= 0 && target < (1L<<32)) {
/*
* We're withing 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(target);
flush(where, 8);
where[1] = SETHI | HIVAL(target, 10);
flush(where, 4);
} else if (target <= 0 && target > -(1L<<32)) {
/*
* We're withing 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;
flush(where, 12);
where[2] = XOR | ((~target) & 0x00001fff);
flush(where, 8);
where[1] = SETHI | HIVAL(~target, 10);
flush(where, 4);
} else if (offset <= (1L<<32) && offset >= -((1L<<32) - 4)) {
/*
* We're withing 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;
flush(where, 12);
where[2] = CALL | ((offset >> 4) & 0x3fffffff);
flush(where, 8);
where[1] = MOV71;
flush(where, 4);
} else if (offset >= 0 && offset < (1L<<44)) {
/*
* We're withing 44 bits. We can generate this pattern:
*
* The resulting code in the jump slot is:
*
* sethi %hi(. - .PLT0), %g1
* sethi %h44(addr), %g1
* or %g1, %m44(addr), %g1
* sllx %g1, 12, %g1
* jmp %g1+%l44(addr)
* nop
* nop
* nop
*
*/
where[4] = JMP | LOVAL(offset);
flush(where, 16);
where[3] = SLLX | 12;
flush(where, 12);
where[2] = OR | (((offset) >> 12) & 0x00001fff);
flush(where, 8);
where[1] = SETHI | HIVAL(offset, 22);
flush(where, 4);
} else if (offset < 0 && offset > -(1L<<44)) {
/*
* We're withing 44 bits. We can generate this pattern:
*
* The resulting code in the jump slot is:
*
* sethi %hi(. - .PLT0), %g1
* sethi %h44(-addr), %g1
* xor %g1, %m44(-addr), %g1
* sllx %g1, 12, %g1
* jmp %g1+%l44(addr)
* nop
* nop
* nop
*
*/
where[4] = JMP | LOVAL(offset);
flush(where, 16);
where[3] = SLLX | 12;
flush(where, 12);
where[2] = XOR | (((~offset) >> 12) & 0x00001fff);
flush(where, 8);
where[1] = SETHI | HIVAL(~offset, 22);
flush(where, 4);
} else {
/*
* We need to load all 64-bits
*
* The resulting code in the jump slot is:
*
* sethi %hi(. - .PLT0), %g1
* sethi %hh(addr), %g1
* sethi %lm(addr), %g5
* or %g1, %hm(addr), %g1
* sllx %g1, 32, %g1
* or %g1, %g5, %g1
* jmp %g1+%lo(addr)
* nop
*
*/
where[6] = JMP | LOVAL(target);
flush(where, 24);
where[5] = ORG5;
flush(where, 20);
where[4] = SLLX | 12;
flush(where, 16);
where[3] = OR | LOVAL((target) >> 32);
flush(where, 12);
where[2] = SETHIG5 | HIVAL(target, 10);
flush(where, 8);
where[1] = SETHI | HIVAL(target, 42);
flush(where, 4);
}
} else {
/*
* This is a high PLT slot; the relocation offset specifies a
* pointer that needs to be frobbed; no actual code needs to
* be modified. The pointer to be calculated needs the addend
* added and the reference object relocation base subtraced.
*/
*wherep = target + rela->r_addend -
(Elf_Addr)refobj->relocbase;
}
return (target);
}
/*
* 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
init_pltgot(Obj_Entry *obj)
{
Elf_Half *entry;
if (obj->pltgot != NULL) {
entry = (Elf_Half *)obj->pltgot;
install_plt(&entry[0], (Elf_Addr)_rtld_bind_start_0);
install_plt(&entry[8], (Elf_Addr)_rtld_bind_start_1);
obj->pltgot[8] = (Elf_Addr)obj;
}
}
static void
install_plt(Elf_Half *pltgot, Elf_Addr proc)
{
pltgot[0] = SAVE;
flush(pltgot, 0);
pltgot[1] = SETHI_l0 | HIVAL(proc, 42);
flush(pltgot, 4);
pltgot[2] = SETHI_l1 | HIVAL(proc, 10);
flush(pltgot, 8);
pltgot[3] = OR_l0_l0 | LOVAL((proc) >> 32);
flush(pltgot, 12);
pltgot[4] = SLLX_l0_32_l0;
flush(pltgot, 16);
pltgot[5] = OR_l0_l1_l0;
flush(pltgot, 20);
pltgot[6] = JMPL_l0_o1 | LOVAL(proc);
flush(pltgot, 24);
pltgot[7] = MOV_g1_o0;
flush(pltgot, 28);
}
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