elf_machdep.c revision 95410
1/*-
2 * Copyright (c) 2001 Jake Burkholder.
3 * Copyright (c) 2000 Eduardo Horvath.
4 * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Paul Kranenburg.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *        This product includes software developed by the NetBSD
21 *        Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 *    contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 *
38 *	from: NetBSD: mdreloc.c,v 1.5 2001/04/25 12:24:51 kleink Exp
39 * $FreeBSD: head/sys/sparc64/sparc64/elf_machdep.c 95410 2002-04-25 01:22:16Z marcel $
40 */
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/linker.h>
45#include <machine/elf.h>
46
47#include "linker_if.h"
48
49/*
50 * The following table holds for each relocation type:
51 *	- the width in bits of the memory location the relocation
52 *	  applies to (not currently used)
53 *	- the number of bits the relocation value must be shifted to the
54 *	  right (i.e. discard least significant bits) to fit into
55 *	  the appropriate field in the instruction word.
56 *	- flags indicating whether
57 *		* the relocation involves a symbol
58 *		* the relocation is relative to the current position
59 *		* the relocation is for a GOT entry
60 *		* the relocation is relative to the load address
61 *
62 */
63#define _RF_S		0x80000000		/* Resolve symbol */
64#define _RF_A		0x40000000		/* Use addend */
65#define _RF_P		0x20000000		/* Location relative */
66#define _RF_G		0x10000000		/* GOT offset */
67#define _RF_B		0x08000000		/* Load address relative */
68#define _RF_U		0x04000000		/* Unaligned */
69#define _RF_SZ(s)	(((s) & 0xff) << 8)	/* memory target size */
70#define _RF_RS(s)	( (s) & 0xff)		/* right shift */
71static int reloc_target_flags[] = {
72	0,							/* NONE */
73	_RF_S|_RF_A|		_RF_SZ(8)  | _RF_RS(0),		/* RELOC_8 */
74	_RF_S|_RF_A|		_RF_SZ(16) | _RF_RS(0),		/* RELOC_16 */
75	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* RELOC_32 */
76	_RF_S|_RF_A|_RF_P|	_RF_SZ(8)  | _RF_RS(0),		/* DISP_8 */
77	_RF_S|_RF_A|_RF_P|	_RF_SZ(16) | _RF_RS(0),		/* DISP_16 */
78	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(0),		/* DISP_32 */
79	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WDISP_30 */
80	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WDISP_22 */
81	      _RF_A|	  _RF_B|_RF_SZ(32) | _RF_RS(10),	/* HI22 */
82	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 22 */
83	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 13 */
84	      _RF_A|	  _RF_B|_RF_SZ(32) | _RF_RS(0),		/* LO10 */
85	_RF_G|			_RF_SZ(32) | _RF_RS(0),		/* GOT10 */
86	_RF_G|			_RF_SZ(32) | _RF_RS(0),		/* GOT13 */
87	_RF_G|			_RF_SZ(32) | _RF_RS(10),	/* GOT22 */
88	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(0),		/* PC10 */
89	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(10),	/* PC22 */
90	      _RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WPLT30 */
91				_RF_SZ(32) | _RF_RS(0),		/* COPY */
92	_RF_S|_RF_A|		_RF_SZ(64) | _RF_RS(0),		/* GLOB_DAT */
93				_RF_SZ(32) | _RF_RS(0),		/* JMP_SLOT */
94	      _RF_A|	  _RF_B|_RF_SZ(64) | _RF_RS(0),		/* RELATIVE */
95	_RF_S|_RF_A|	  _RF_U|_RF_SZ(32) | _RF_RS(0),		/* UA_32 */
96
97	      _RF_A|		_RF_SZ(32) | _RF_RS(0),		/* PLT32 */
98	      _RF_A|		_RF_SZ(32) | _RF_RS(10),	/* HIPLT22 */
99	      _RF_A|		_RF_SZ(32) | _RF_RS(0),		/* LOPLT10 */
100	      _RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(0),		/* PCPLT32 */
101	      _RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(10),	/* PCPLT22 */
102	      _RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(0),		/* PCPLT10 */
103	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 10 */
104	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 11 */
105	_RF_S|_RF_A|		_RF_SZ(64) | _RF_RS(0),		/* 64 */
106	_RF_S|_RF_A|/*extra*/	_RF_SZ(32) | _RF_RS(0),		/* OLO10 */
107	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(42),	/* HH22 */
108	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(32),	/* HM10 */
109	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(10),	/* LM22 */
110	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(42),	/* PC_HH22 */
111	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(32),	/* PC_HM10 */
112	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(10),	/* PC_LM22 */
113	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WDISP16 */
114	_RF_S|_RF_A|_RF_P|	_RF_SZ(32) | _RF_RS(2),		/* WDISP19 */
115	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* GLOB_JMP */
116	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 7 */
117	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 5 */
118	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* 6 */
119	_RF_S|_RF_A|_RF_P|	_RF_SZ(64) | _RF_RS(0),		/* DISP64 */
120	      _RF_A|		_RF_SZ(64) | _RF_RS(0),		/* PLT64 */
121	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(10),	/* HIX22 */
122	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* LOX10 */
123	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(22),	/* H44 */
124	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(12),	/* M44 */
125	_RF_S|_RF_A|		_RF_SZ(32) | _RF_RS(0),		/* L44 */
126	_RF_S|_RF_A|		_RF_SZ(64) | _RF_RS(0),		/* REGISTER */
127	_RF_S|_RF_A|	_RF_U|	_RF_SZ(64) | _RF_RS(0),		/* UA64 */
128	_RF_S|_RF_A|	_RF_U|	_RF_SZ(16) | _RF_RS(0),		/* UA16 */
129};
130
131#define RELOC_RESOLVE_SYMBOL(t)		((reloc_target_flags[t] & _RF_S) != 0)
132#define RELOC_PC_RELATIVE(t)		((reloc_target_flags[t] & _RF_P) != 0)
133#define RELOC_BASE_RELATIVE(t)		((reloc_target_flags[t] & _RF_B) != 0)
134#define RELOC_UNALIGNED(t)		((reloc_target_flags[t] & _RF_U) != 0)
135#define RELOC_USE_ADDEND(t)		((reloc_target_flags[t] & _RF_A) != 0)
136#define RELOC_TARGET_SIZE(t)		((reloc_target_flags[t] >> 8) & 0xff)
137#define RELOC_VALUE_RIGHTSHIFT(t)	(reloc_target_flags[t] & 0xff)
138
139static long reloc_target_bitmask[] = {
140#define _BM(x)	(~(-(1ULL << (x))))
141	0,				/* NONE */
142	_BM(8), _BM(16), _BM(32),	/* RELOC_8, _16, _32 */
143	_BM(8), _BM(16), _BM(32),	/* DISP8, DISP16, DISP32 */
144	_BM(30), _BM(22),		/* WDISP30, WDISP22 */
145	_BM(22), _BM(22),		/* HI22, _22 */
146	_BM(13), _BM(10),		/* RELOC_13, _LO10 */
147	_BM(10), _BM(13), _BM(22),	/* GOT10, GOT13, GOT22 */
148	_BM(10), _BM(22),		/* _PC10, _PC22 */
149	_BM(30), 0,			/* _WPLT30, _COPY */
150	_BM(32), _BM(32), _BM(32),	/* _GLOB_DAT, JMP_SLOT, _RELATIVE */
151	_BM(32), _BM(32),		/* _UA32, PLT32 */
152	_BM(22), _BM(10),		/* _HIPLT22, LOPLT10 */
153	_BM(32), _BM(22), _BM(10),	/* _PCPLT32, _PCPLT22, _PCPLT10 */
154	_BM(10), _BM(11), -1,		/* _10, _11, _64 */
155	_BM(10), _BM(22),		/* _OLO10, _HH22 */
156	_BM(10), _BM(22),		/* _HM10, _LM22 */
157	_BM(22), _BM(10), _BM(22),	/* _PC_HH22, _PC_HM10, _PC_LM22 */
158	_BM(16), _BM(19),		/* _WDISP16, _WDISP19 */
159	-1,				/* GLOB_JMP */
160	_BM(7), _BM(5), _BM(6)		/* _7, _5, _6 */
161	-1, -1,				/* DISP64, PLT64 */
162	_BM(22), _BM(13),		/* HIX22, LOX10 */
163	_BM(22), _BM(10), _BM(13),	/* H44, M44, L44 */
164	-1, -1, _BM(16),		/* REGISTER, UA64, UA16 */
165#undef _BM
166};
167#define RELOC_VALUE_BITMASK(t)	(reloc_target_bitmask[t])
168
169/* Process one elf relocation with addend. */
170int
171elf_reloc(linker_file_t lf, const void *data, int type)
172{
173	const Elf_Rela *rela;
174	Elf_Addr relocbase;
175	Elf_Half *where32;
176	Elf_Addr *where;
177	Elf_Word rtype, symidx;
178	Elf_Addr value;
179	Elf_Addr mask;
180	caddr_t addr;
181
182	if (type != ELF_RELOC_RELA)
183		return (-1);
184
185	relocbase = (Elf_Addr)lf->address;
186	rela = (const Elf_Rela *)data;
187	where = (Elf_Addr *)(relocbase + rela->r_offset);
188	where32 = (Elf_Half *)where;
189	rtype = ELF_R_TYPE(rela->r_info);
190	symidx = ELF_R_SYM(rela->r_info);
191
192	if (rtype == R_SPARC_NONE)
193		return (0);
194
195	if (rtype == R_SPARC_JMP_SLOT || rtype == R_SPARC_COPY ||
196	    rtype > R_SPARC_UA16)
197		return (-1);
198
199	if (RELOC_UNALIGNED(rtype))
200		return (-1);
201
202	value = rela->r_addend;
203
204	if (RELOC_RESOLVE_SYMBOL(rtype)) {
205		addr = elf_lookup(lf, symidx, 1);
206		if (addr == 0)
207			return (-1);
208		value += (Elf_Addr)addr;
209	}
210
211	if (RELOC_PC_RELATIVE(rtype))
212		value -= (Elf_Addr)where;
213
214	if (RELOC_BASE_RELATIVE(rtype))
215		value += (Elf_Addr)(relocbase);
216
217	mask = RELOC_VALUE_BITMASK(rtype);
218	value >>= RELOC_VALUE_RIGHTSHIFT(rtype);
219	value &= mask;
220
221	if (RELOC_TARGET_SIZE(rtype) > 32) {
222		*where &= ~mask;
223		*where |= value;
224	} else {
225		*where32 &= ~mask;
226		*where32 |= value;
227	}
228
229	return (0);
230}
231