1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#include	<string.h>
28#include	"machdep.h"
29#include	"reloc.h"
30#include	"_librtld.h"
31#include	"_elf.h"
32
33/*
34 * Undo relocations that have been applied to a memory image.  Basically this
35 * involves copying the original files relocation offset into the new image
36 * being created.
37 */
38void
39undo_reloc(void *vrel, uchar_t *oaddr, uchar_t *iaddr, Reloc *reloc)
40{
41	Rel	*rel = vrel;
42	/* LINTED */
43	ulong_t	*_oaddr = (ulong_t *)oaddr;
44	/* LINTED */
45	ulong_t	*_iaddr = (ulong_t *)iaddr;
46
47	switch (ELF_R_TYPE(rel->r_info, M_MACH)) {
48	case R_386_NONE:
49		break;
50
51	case R_386_COPY:
52		(void) memset((void *)oaddr, 0, (size_t)reloc->r_size);
53		break;
54
55	case R_386_JMP_SLOT:
56		if (_iaddr)
57			*_oaddr = *_iaddr + reloc->r_value;
58		else
59			*_oaddr = reloc->r_value;
60		break;
61
62	default:
63		if (_iaddr)
64			*_oaddr = *_iaddr;
65		else
66			*_oaddr = 0;
67		break;
68	}
69}
70
71/*
72 * Copy a relocation record and increment its value.  The record must reflect
73 * the new address to which this image is fixed.  Note that .got entries
74 * associated with .plt's must be fixed to the new base address.
75 */
76void
77inc_reloc(void *vnrel, void *vorel, Reloc *reloc, uchar_t *oaddr,
78    uchar_t *iaddr)
79{
80	Rel	*nrel = vnrel;
81	Rel	*orel = vorel;
82	/* LINTED */
83	ulong_t	*_oaddr = (ulong_t *)oaddr;
84	/* LINTED */
85	ulong_t	*_iaddr = (ulong_t *)iaddr;
86
87	if (ELF_R_TYPE(nrel->r_info, M_MACH) == R_386_JMP_SLOT) {
88		if (_iaddr)
89			*_oaddr = *_iaddr + reloc->r_value;
90		else
91			*_oaddr = reloc->r_value;
92	}
93
94	*nrel = *orel;
95	nrel->r_offset += reloc->r_value;
96}
97
98/*
99 * Clear a relocation record.  The relocation has been applied to the image and
100 * thus the relocation must not occur again.
101 */
102void
103clear_reloc(void *vrel)
104{
105	Rel	*rel = vrel;
106
107	rel->r_offset = 0;
108	rel->r_info = ELF_R_INFO(0, R_386_NONE);
109}
110
111/*
112 * Apply a relocation to an image being built from an input file.  Use the
113 * runtime linkers routines to do the necessary magic.
114 */
115void
116apply_reloc(void *vrel, Reloc *reloc, const char *name, uchar_t *oaddr,
117    Rt_map *lmp)
118{
119	Rel	*rel = vrel;
120	Xword	type = ELF_R_TYPE(rel->r_info, M_MACH);
121	Word	value = reloc->r_value;
122
123	if (type == R_386_JMP_SLOT) {
124		uintptr_t	addr, vaddr;
125
126		if (FLAGS(lmp) & FLG_RT_FIXED)
127			vaddr = 0;
128		else
129			vaddr = ADDR(lmp);
130		addr = (uintptr_t)oaddr - rel->r_offset;
131		/* LINTED */
132		(void) elf_plt_write((uintptr_t)addr, vaddr, rel,
133		    (uintptr_t)value, reloc->r_pltndx);
134
135	} else if (type == R_386_COPY) {
136		(void) memcpy((void *)oaddr, (void *)value,
137		    (size_t)reloc->r_size);
138	} else {
139		(void) do_reloc_rtld(type, oaddr, &value, reloc->r_name, name,
140		    LIST(lmp));
141	}
142}
143