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722 lines
21 KiB
C
722 lines
21 KiB
C
/* $NetBSD: mdreloc.c,v 1.5 2001/04/25 12:24:51 kleink Exp $ */
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/*-
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* Copyright (c) 2000 Eduardo Horvath.
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* Copyright (c) 1999 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Paul Kranenburg.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/mman.h>
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "debug.h"
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#include "rtld.h"
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/*
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* The following table holds for each relocation type:
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* - the width in bits of the memory location the relocation
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* applies to (not currently used)
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* - the number of bits the relocation value must be shifted to the
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* right (i.e. discard least significant bits) to fit into
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* the appropriate field in the instruction word.
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* - flags indicating whether
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* * the relocation involves a symbol
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* * the relocation is relative to the current position
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* * the relocation is for a GOT entry
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* * the relocation is relative to the load address
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*
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*/
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#define _RF_S 0x80000000 /* Resolve symbol */
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#define _RF_A 0x40000000 /* Use addend */
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#define _RF_P 0x20000000 /* Location relative */
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#define _RF_G 0x10000000 /* GOT offset */
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#define _RF_B 0x08000000 /* Load address relative */
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#define _RF_U 0x04000000 /* Unaligned */
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#define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */
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#define _RF_RS(s) ( (s) & 0xff) /* right shift */
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static int reloc_target_flags[] = {
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0, /* NONE */
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_RF_S|_RF_A| _RF_SZ(8) | _RF_RS(0), /* RELOC_8 */
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_RF_S|_RF_A| _RF_SZ(16) | _RF_RS(0), /* RELOC_16 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* RELOC_32 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(8) | _RF_RS(0), /* DISP_8 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(16) | _RF_RS(0), /* DISP_16 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* DISP_32 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_30 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_22 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HI22 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 22 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 13 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LO10 */
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_RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT10 */
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_RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT13 */
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_RF_G| _RF_SZ(32) | _RF_RS(10), /* GOT22 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PC10 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC22 */
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_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WPLT30 */
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_RF_SZ(32) | _RF_RS(0), /* COPY */
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_RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* GLOB_DAT */
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_RF_SZ(32) | _RF_RS(0), /* JMP_SLOT */
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_RF_A| _RF_B| _RF_SZ(64) | _RF_RS(0), /* RELATIVE */
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_RF_S|_RF_A| _RF_U| _RF_SZ(32) | _RF_RS(0), /* UA_32 */
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_RF_A| _RF_SZ(32) | _RF_RS(0), /* PLT32 */
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_RF_A| _RF_SZ(32) | _RF_RS(10), /* HIPLT22 */
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_RF_A| _RF_SZ(32) | _RF_RS(0), /* LOPLT10 */
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_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT32 */
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_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PCPLT22 */
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_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT10 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 10 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 11 */
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_RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* 64 */
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_RF_S|_RF_A|/*extra*/ _RF_SZ(32) | _RF_RS(0), /* OLO10 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(42), /* HH22 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(32), /* HM10 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* LM22 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(42), /* PC_HH22 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(32), /* PC_HM10 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC_LM22 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP16 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP19 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* GLOB_JMP */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 7 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 5 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 6 */
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_RF_S|_RF_A|_RF_P| _RF_SZ(64) | _RF_RS(0), /* DISP64 */
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_RF_A| _RF_SZ(64) | _RF_RS(0), /* PLT64 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HIX22 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LOX10 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(22), /* H44 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(12), /* M44 */
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_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* L44 */
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_RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* REGISTER */
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_RF_S|_RF_A| _RF_U| _RF_SZ(64) | _RF_RS(0), /* UA64 */
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_RF_S|_RF_A| _RF_U| _RF_SZ(16) | _RF_RS(0), /* UA16 */
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};
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#if 0
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static const char *reloc_names[] = {
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"NONE", "RELOC_8", "RELOC_16", "RELOC_32", "DISP_8",
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"DISP_16", "DISP_32", "WDISP_30", "WDISP_22", "HI22",
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"22", "13", "LO10", "GOT10", "GOT13",
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"GOT22", "PC10", "PC22", "WPLT30", "COPY",
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"GLOB_DAT", "JMP_SLOT", "RELATIVE", "UA_32", "PLT32",
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"HIPLT22", "LOPLT10", "LOPLT10", "PCPLT22", "PCPLT32",
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"10", "11", "64", "OLO10", "HH22",
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"HM10", "LM22", "PC_HH22", "PC_HM10", "PC_LM22",
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"WDISP16", "WDISP19", "GLOB_JMP", "7", "5", "6",
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"DISP64", "PLT64", "HIX22", "LOX10", "H44", "M44",
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"L44", "REGISTER", "UA64", "UA16"
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};
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#endif
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#define RELOC_RESOLVE_SYMBOL(t) ((reloc_target_flags[t] & _RF_S) != 0)
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#define RELOC_PC_RELATIVE(t) ((reloc_target_flags[t] & _RF_P) != 0)
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#define RELOC_BASE_RELATIVE(t) ((reloc_target_flags[t] & _RF_B) != 0)
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#define RELOC_UNALIGNED(t) ((reloc_target_flags[t] & _RF_U) != 0)
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#define RELOC_USE_ADDEND(t) ((reloc_target_flags[t] & _RF_A) != 0)
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#define RELOC_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff)
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#define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff)
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static long reloc_target_bitmask[] = {
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#define _BM(x) (~(-(1ULL << (x))))
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0, /* NONE */
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_BM(8), _BM(16), _BM(32), /* RELOC_8, _16, _32 */
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_BM(8), _BM(16), _BM(32), /* DISP8, DISP16, DISP32 */
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_BM(30), _BM(22), /* WDISP30, WDISP22 */
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_BM(22), _BM(22), /* HI22, _22 */
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_BM(13), _BM(10), /* RELOC_13, _LO10 */
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_BM(10), _BM(13), _BM(22), /* GOT10, GOT13, GOT22 */
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_BM(10), _BM(22), /* _PC10, _PC22 */
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_BM(30), 0, /* _WPLT30, _COPY */
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_BM(32), _BM(32), _BM(32), /* _GLOB_DAT, JMP_SLOT, _RELATIVE */
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_BM(32), _BM(32), /* _UA32, PLT32 */
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_BM(22), _BM(10), /* _HIPLT22, LOPLT10 */
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_BM(32), _BM(22), _BM(10), /* _PCPLT32, _PCPLT22, _PCPLT10 */
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_BM(10), _BM(11), -1, /* _10, _11, _64 */
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_BM(10), _BM(22), /* _OLO10, _HH22 */
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_BM(10), _BM(22), /* _HM10, _LM22 */
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_BM(22), _BM(10), _BM(22), /* _PC_HH22, _PC_HM10, _PC_LM22 */
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_BM(16), _BM(19), /* _WDISP16, _WDISP19 */
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-1, /* GLOB_JMP */
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_BM(7), _BM(5), _BM(6), /* _7, _5, _6 */
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-1, -1, /* DISP64, PLT64 */
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_BM(22), _BM(13), /* HIX22, LOX10 */
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_BM(22), _BM(10), _BM(13), /* H44, M44, L44 */
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-1, -1, _BM(16), /* REGISTER, UA64, UA16 */
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#undef _BM
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};
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#define RELOC_VALUE_BITMASK(t) (reloc_target_bitmask[t])
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#undef flush
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#define flush(va, offs) \
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__asm __volatile("flush %0 + %1" : : "r" (va), "I" (offs));
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static int reloc_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela,
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SymCache *cache);
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static void install_plt(Elf_Half *pltgot, Elf_Addr proc);
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extern char _rtld_bind_start_0[];
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extern char _rtld_bind_start_1[];
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int
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do_copy_relocations(Obj_Entry *dstobj)
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{
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const Elf_Rela *relalim;
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const Elf_Rela *rela;
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const Elf_Sym *dstsym;
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const Elf_Sym *srcsym;
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void *dstaddr;
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const void *srcaddr;
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Obj_Entry *srcobj;
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unsigned long hash;
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const char *name;
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size_t size;
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assert(dstobj->mainprog); /* COPY relocations are invalid elsewhere */
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relalim = (const Elf_Rela *)((caddr_t)dstobj->rela + dstobj->relasize);
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for (rela = dstobj->rela; rela < relalim; rela++) {
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if (ELF_R_TYPE(rela->r_info) == R_SPARC_COPY) {
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dstaddr = (void *)(dstobj->relocbase + rela->r_offset);
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dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info);
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name = dstobj->strtab + dstsym->st_name;
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hash = elf_hash(name);
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size = dstsym->st_size;
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for (srcobj = dstobj->next; srcobj != NULL;
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srcobj = srcobj->next)
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if ((srcsym = symlook_obj(name, hash, srcobj,
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false)) != NULL)
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break;
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if (srcobj == NULL) {
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_rtld_error("Undefined symbol \"%s\""
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"referenced from COPY relocation"
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"in %s", name, dstobj->path);
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return (-1);
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}
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srcaddr = (const void *)(srcobj->relocbase +
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srcsym->st_value);
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memcpy(dstaddr, srcaddr, size);
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}
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}
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return (0);
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}
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int
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reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
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{
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const Elf_Rela *relalim;
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const Elf_Rela *rela;
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SymCache *cache;
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int bytes = obj->nchains * sizeof(SymCache);
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int r = -1;
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/*
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* The dynamic loader may be called from a thread, we have
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* limited amounts of stack available so we cannot use alloca().
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*/
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cache = mmap(NULL, bytes, PROT_READ|PROT_WRITE, MAP_ANON, -1, 0);
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if (cache == MAP_FAILED)
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cache = NULL;
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if (cache != NULL)
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memset(cache, 0, obj->nchains * sizeof(SymCache));
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relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize);
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for (rela = obj->rela; rela < relalim; rela++) {
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if (reloc_nonplt_object(obj, rela, cache) < 0)
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goto done;
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}
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r = 0;
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done:
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if (cache)
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munmap(cache, bytes);
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return (r);
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}
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static int
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reloc_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela, SymCache *cache)
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{
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const Obj_Entry *defobj;
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const Elf_Sym *def;
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Elf_Addr *where;
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Elf_Half *where32;
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Elf_Word type;
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Elf_Addr value;
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Elf_Addr mask;
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where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
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where32 = (Elf_Half *)where;
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defobj = NULL;
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def = NULL;
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type = ELF_R_TYPE(rela->r_info);
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if (type == R_SPARC_NONE)
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return (0);
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/* We do JMP_SLOTs below */
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if (type == R_SPARC_JMP_SLOT)
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return (0);
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/* COPY relocs are also handled elsewhere */
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if (type == R_SPARC_COPY)
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return (0);
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/*
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* Note: R_SPARC_UA16 must be numerically largest relocation type.
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*/
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if (type > R_SPARC_UA16)
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return (-1);
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value = rela->r_addend;
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/*
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* Handle relative relocs here, because we might not
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* be able to access globals yet.
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*/
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if (type == R_SPARC_RELATIVE) {
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/* XXXX -- apparently we ignore the preexisting value */
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*where = (Elf_Addr)(obj->relocbase + value);
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return (0);
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}
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/*
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* If we get here while relocating rtld itself, we will crash because
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* a non-local variable is accessed.
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*/
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if (RELOC_RESOLVE_SYMBOL(type)) {
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/* Find the symbol */
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def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
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false, cache);
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if (def == NULL)
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return (-1);
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/* Add in the symbol's absolute address */
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value += (Elf_Addr)(defobj->relocbase + def->st_value);
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}
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if (RELOC_PC_RELATIVE(type))
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value -= (Elf_Addr)where;
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if (RELOC_BASE_RELATIVE(type)) {
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/*
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* Note that even though sparcs use `Elf_rela' exclusively
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* we still need the implicit memory addend in relocations
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* referring to GOT entries. Undoubtedly, someone f*cked
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* this up in the distant past, and now we're stuck with
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* it in the name of compatibility for all eternity..
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*
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* In any case, the implicit and explicit should be mutually
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* exclusive. We provide a check for that here.
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*/
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/* XXXX -- apparently we ignore the preexisting value */
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value += (Elf_Addr)(obj->relocbase);
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}
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mask = RELOC_VALUE_BITMASK(type);
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value >>= RELOC_VALUE_RIGHTSHIFT(type);
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value &= mask;
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if (RELOC_UNALIGNED(type)) {
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/* Handle unaligned relocations. */
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Elf_Addr tmp;
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char *ptr;
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int size;
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int i;
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size = RELOC_TARGET_SIZE(type) / 8;
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ptr = (char *)where;
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tmp = 0;
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/* Read it in one byte at a time. */
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for (i = 0; i < size; i++)
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tmp = (tmp << 8) | ptr[i];
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tmp &= ~mask;
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tmp |= value;
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/* Write it back out. */
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for (i = 0; i < size; i++)
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ptr[i] = ((tmp >> ((size - i - 1) * 8)) & 0xff);
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} else if (RELOC_TARGET_SIZE(type) > 32) {
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*where &= ~mask;
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*where |= value;
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} else {
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*where32 &= ~mask;
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*where32 |= value;
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}
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return (0);
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}
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|
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);
|
|
}
|