jimzah/freebsd-src
1
0
Fork 0
mirror of https://github.com/freebsd/freebsd-src.git synced 2024-12-03 14:48:57 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity
4105901933
freebsd-src/libexec/rtld-elf/sparc64/reloc.c
Michal Meloun 4849c3a570 Improve R_AARCH64_TLSDESC relocation. 
The original code did not support dynamically loaded libraries and used
suboptimal access to TLS variables.
New implementation removes lazy resolving of TLS relocation - due to flaw
in TLSDESC design is impossible to switch resolver function at runtime
without expensive locking.

Due to this, 3 specialized resolvers are implemented:
 - load time resolver for TLS relocation from libraries loaded with main
   executable (thus with known TLS offset).
 - resolver for undefined thread weak symbols.
 - slower lazy resolver for dynamically loaded libraries with fast path for
   already resolved symbols.

PR:		228892, 232149, 233204, 232311
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D18417
2018-12-15 10:38:07 +00:00

879 lines
26 KiB
C
Raw Blame History

/* $NetBSD: mdreloc.c,v 1.42 2008/04/28 20:23:04 martin Exp $ */
/*-
* SPDX-License-Identifier: BSD-2-Clause-NetBSD
*
* 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.
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#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_X 0x02000000 /* Bare symbols, needs proc */
#define _RF_D 0x01000000 /* Use dynamic TLS offset */
#define _RF_O 0x00800000 /* Use static TLS offset */
#define _RF_I 0x00400000 /* Use TLS object ID */
#define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */
#define _RF_RS(s) ( (s) & 0xff) /* right shift */
static const int reloc_target_flags[] = {
0, /* NONE */
_RF_S|_RF_A| _RF_SZ(8) | _RF_RS(0), /* 8 */
_RF_S|_RF_A| _RF_SZ(16) | _RF_RS(0), /* 16 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 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_X| _RF_SZ(32) | _RF_RS(10), /* HI22 */
_RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 22 */
_RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 13 */
_RF_S|_RF_A|_RF_X| _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_X| _RF_SZ(32) | _RF_RS(0), /* 10 */
_RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 11 */
_RF_S|_RF_A|_RF_X| _RF_SZ(64) | _RF_RS(0), /* 64 */
_RF_S|_RF_A|/*extra*/ _RF_SZ(32) | _RF_RS(0), /* OLO10 */
_RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(42), /* HH22 */
_RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(32), /* HM10 */
_RF_S|_RF_A|_RF_X| _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_X| _RF_SZ(32) | _RF_RS(0), /* 7 */
_RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* 5 */
_RF_S|_RF_A|_RF_X| _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_X| _RF_SZ(32) | _RF_RS(10), /* HIX22 */
_RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(0), /* LOX10 */
_RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(22), /* H44 */
_RF_S|_RF_A|_RF_X| _RF_SZ(32) | _RF_RS(12), /* M44 */
_RF_S|_RF_A|_RF_X| _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 */
/* TLS */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* GD_HI22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* GD_LO10 */
0, /* GD_ADD */
_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* GD_CALL */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* LDM_HI22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LDM_LO10 */
0, /* LDM_ADD */
_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* LDM_CALL */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* LDO_HIX22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LDO_LOX10 */
0, /* LDO_ADD */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* IE_HI22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* IE_LO10 */
0, /* IE_LD */
0, /* IE_LDX */
0, /* IE_ADD */
_RF_S|_RF_A| _RF_O| _RF_SZ(32) | _RF_RS(10), /* LE_HIX22 */
_RF_S|_RF_A| _RF_O| _RF_SZ(32) | _RF_RS(0), /* LE_LOX10 */
_RF_S| _RF_I| _RF_SZ(32) | _RF_RS(0), /* DTPMOD32 */
_RF_S| _RF_I| _RF_SZ(64) | _RF_RS(0), /* DTPMOD64 */
_RF_S|_RF_A| _RF_D| _RF_SZ(32) | _RF_RS(0), /* DTPOFF32 */
_RF_S|_RF_A| _RF_D| _RF_SZ(64) | _RF_RS(0), /* DTPOFF64 */
_RF_S|_RF_A| _RF_O| _RF_SZ(32) | _RF_RS(0), /* TPOFF32 */
_RF_S|_RF_A| _RF_O| _RF_SZ(64) | _RF_RS(0) /* TPOFF64 */
};
#if 0
static const char *const reloc_names[] = {
"NONE", "8", "16", "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", "GD_HI22", "GD_LO10", "GD_ADD",
"GD_CALL", "LDM_HI22", "LDMO10", "LDM_ADD", "LDM_CALL", "LDO_HIX22",
"LDO_LOX10", "LDO_ADD", "IE_HI22", "IE_LO10", "IE_LD", "IE_LDX",
"IE_ADD", "LE_HIX22", "LE_LOX10", "DTPMOD32", "DTPMOD64", "DTPOFF32",
"DTPOFF64", "TPOFF32", "TPOFF64"
};
#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_BARE_SYMBOL(t) ((reloc_target_flags[t] & _RF_X) != 0)
#define RELOC_USE_TLS_DOFF(t) ((reloc_target_flags[t] & _RF_D) != 0)
#define RELOC_USE_TLS_OFF(t) ((reloc_target_flags[t] & _RF_O) != 0)
#define RELOC_USE_TLS_ID(t) ((reloc_target_flags[t] & _RF_I) != 0)
#define RELOC_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff)
#define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff)
static const long reloc_target_bitmask[] = {
#define _BM(x) (~(-(1ULL << (x))))
0, /* NONE */
_BM(8), _BM(16), _BM(32), /* 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), /* 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(13), _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 */
_BM(22), _BM(10), 0, _BM(30), /* GD_HI22, GD_LO10, GD_ADD, GD_CALL */
_BM(22), _BM(10), 0, /* LDM_HI22, LDMO10, LDM_ADD */
_BM(30), /* LDM_CALL */
_BM(22), _BM(10), 0, /* LDO_HIX22, LDO_LOX10, LDO_ADD */
_BM(22), _BM(10), 0, 0, /* IE_HI22, IE_LO10, IE_LD, IE_LDX */
0, /* IE_ADD */
_BM(22), _BM(13), /* LE_HIX22, LE_LOX10 */
_BM(32), -1, /* DTPMOD32, DTPMOD64 */
_BM(32), -1, /* DTPOFF32, DTPOFF64 */
_BM(32), -1 /* TPOFF32, TPOFF64 */
#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, int flags, RtldLockState *lockstate);
static void install_plt(Elf_Word *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;
const Obj_Entry *srcobj, *defobj;
SymLook req;
const char *name;
size_t size;
int res;
assert(dstobj->mainprog); /* COPY relocations are invalid elsewhere */
relalim = (const Elf_Rela *)((const char *)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;
size = dstsym->st_size;
symlook_init(&req, name);
req.ventry = fetch_ventry(dstobj,
ELF_R_SYM(rela->r_info));
req.flags = SYMLOOK_EARLY;
for (srcobj = globallist_next(dstobj); srcobj != NULL;
srcobj = globallist_next(srcobj)) {
res = symlook_obj(&req, srcobj);
if (res == 0) {
srcsym = req.sym_out;
defobj = req.defobj_out;
break;
}
}
if (srcobj == NULL) {
_rtld_error("Undefined symbol \"%s\""
"referenced from COPY relocation"
"in %s", name, dstobj->path);
return (-1);
}
srcaddr = (const void *)(defobj->relocbase +
srcsym->st_value);
memcpy(dstaddr, srcaddr, size);
}
}
return (0);
}
int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
RtldLockState *lockstate)
{
const Elf_Rela *relalim;
const Elf_Rela *rela;
SymCache *cache;
int r = -1;
if ((flags & SYMLOOK_IFUNC) != 0)
/* XXX not implemented */
return (0);
/*
* The dynamic loader may be called from a thread, we have
* limited amounts of stack available so we cannot use alloca().
*/
if (obj != obj_rtld) {
cache = calloc(obj->dynsymcount, sizeof(SymCache));
/* No need to check for NULL here */
} else
cache = NULL;
relalim = (const Elf_Rela *)((const char *)obj->rela + obj->relasize);
for (rela = obj->rela; rela < relalim; rela++) {
if (reloc_nonplt_object(obj, rela, cache, flags, lockstate) < 0)
goto done;
}
r = 0;
done:
if (cache != NULL)
free(cache);
return (r);
}
static int
reloc_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela, SymCache *cache,
int flags, RtldLockState *lockstate)
{
const Obj_Entry *defobj;
const Elf_Sym *def;
Elf_Addr *where;
Elf_Word *where32;
Elf_Word type;
Elf_Addr value;
Elf_Addr mask;
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
where32 = (Elf_Word *)where;
defobj = NULL;
def = NULL;
type = ELF64_R_TYPE_ID(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);
/* Ignore ADD and CALL relocations for dynamic TLS references. */
if (type == R_SPARC_TLS_GD_ADD || type == R_SPARC_TLS_GD_CALL ||
type == R_SPARC_TLS_LDM_ADD || type == R_SPARC_TLS_LDM_CALL ||
type == R_SPARC_TLS_LDO_ADD)
return (0);
/*
* Note: R_SPARC_TLS_TPOFF64 must be the numerically largest
* relocation type.
*/
if (type >= nitems(reloc_target_bitmask)) {
_rtld_error("%s: Unsupported relocation type %d in non-PLT "
"object\n", obj->path, type);
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,
flags, cache, lockstate);
if (def == NULL)
return (-1);
if (RELOC_USE_TLS_ID(type))
value = (Elf_Addr)defobj->tlsindex;
else if (RELOC_USE_TLS_DOFF(type))
value += (Elf_Addr)def->st_value;
else if (RELOC_USE_TLS_OFF(type)) {
/*
* We lazily allocate offsets for static TLS as we
* see the first relocation that references the TLS
* block. This allows us to support (small amounts
* of) static TLS in dynamically loaded modules. If
* we run out of space, we generate an error.
*/
if (!defobj->tls_done && !allocate_tls_offset(
__DECONST(Obj_Entry *, defobj))) {
_rtld_error("%s: No space available for "
"static Thread Local Storage", obj->path);
return (-1);
}
value += (Elf_Addr)(def->st_value -
defobj->tlsoffset);
} else {
/* Add in the symbol's absolute address. */
value += (Elf_Addr)(def->st_value +
defobj->relocbase);
}
}
if (type == R_SPARC_OLO10)
value = (value & 0x3ff) + ELF64_R_TYPE_DATA(rela->r_info);
if (type == R_SPARC_HIX22 || type == R_SPARC_TLS_LE_HIX22)
value ^= 0xffffffffffffffff;
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 (type == R_SPARC_LOX10 || type == R_SPARC_TLS_LE_LOX10)
value |= 0x1c00;
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 __unused, int flags __unused,
RtldLockState *lockstate __unused)
{
#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(ELF64_R_TYPE_ID(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,
SYMLOOK_IN_PLT, NULL, lockstate);
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, int flags, RtldLockState *lockstate)
{
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 *)((const char *)obj->pltrela +
obj->pltrelasize);
for (rela = obj->pltrela; rela < relalim; rela++) {
assert(ELF64_R_TYPE_ID(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,
SYMLOOK_IN_PLT | flags, NULL, lockstate);
if (def == NULL)
return -1;
target = (Elf_Addr)(defobj->relocbase + def->st_value);
reloc_jmpslot(where, target, defobj, obj,
(const Elf_Rel *)rela);
}
obj->jmpslots_done = true;
return (0);
}
int
reloc_iresolve(Obj_Entry *obj __unused,
struct Struct_RtldLockState *lockstate __unused)
{
/* XXX not implemented */
return (0);
}
int
reloc_gnu_ifunc(Obj_Entry *obj __unused, int flags __unused,
struct Struct_RtldLockState *lockstate __unused)
{
/* XXX not implemented */
return (0);
}
Elf_Addr
reloc_jmpslot(Elf_Addr *wherep, Elf_Addr target, const Obj_Entry *obj __unused,
const Obj_Entry *refobj, const Elf_Rel *rel)
{
const Elf_Rela *rela = (const Elf_Rela *)rel;
Elf_Addr offset;
Elf_Word *where;
if (ld_bind_not) {
/* Skip any PLT modifications */
} else 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_Word *)wherep;
offset = ((Elf_Addr)where) - target;
if (offset <= (1UL<<20) && offset >= -(1UL<<20)) {
/*
* We're within 1MB -- we can use a direct branch
* instruction.
*
* 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 < (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(target);
flush(where, 8);
where[1] = SETHI | HIVAL(target, 10);
flush(where, 4);
} else if (target > -(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;
flush(where, 12);
where[2] = XOR | ((~target) & 0x00001fff);
flush(where, 8);
where[1] = SETHI | HIVAL(~target, 10);
flush(where, 4);
} else if (offset <= (1UL<<32) && offset >= -((1UL<<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;
flush(where, 12);
where[2] = CALL | ((offset >> 4) & 0x3fffffff);
flush(where, 8);
where[1] = MOV71;
flush(where, 4);
} else if (offset < (1L<<44)) {
/*
* We're within 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 > -(1UL<<44)) {
/*
* We're within 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 | 32;
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);
}
void
ifunc_init(Elf_Auxinfo aux_info[__min_size(AT_COUNT)] __unused)
{
}
extern void __sparc_utrap_setup(void);
void
pre_init(void)
{
__sparc_utrap_setup();
}
/*
* 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_Word *entry;
if (obj->pltgot != NULL) {
entry = (Elf_Word *)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_Word *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);
}
void
allocate_initial_tls(Obj_Entry *objs)
{
Elf_Addr* tpval;
/*
* Fix the size of the static TLS block by using the maximum offset
* allocated so far and adding a bit for dynamic modules to use.
*/
tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA;
tpval = allocate_tls(objs, NULL, 3 * sizeof(Elf_Addr),
sizeof(Elf_Addr));
__asm __volatile("mov %0, %%g7" : : "r" (tpval));
}
void *__tls_get_addr(tls_index *ti)
{
register Elf_Addr** tp __asm__("%g7");
return (tls_get_addr_common(tp, ti->ti_module, ti->ti_offset));
}
Reference in New Issue View Git Blame Copy Permalink