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 */
38/* ARGSUSED3 */
39void
40undo_reloc(void *vrel, uchar_t *oaddr, uchar_t *iaddr, Reloc *reloc)
41{
42	Rela		*rel = vrel;
43	Xword		rtype = ELF_R_TYPE(rel->r_info, M_MACH);
44
45	switch (rtype) {
46	case R_AMD64_NONE:
47		break;
48	case R_AMD64_COPY:
49		(void) memset((void *)oaddr, 0, (size_t)reloc->r_size);
50		break;
51	case R_AMD64_JUMP_SLOT:
52		{
53			/* LINTED */
54			ulong_t *_oaddr = (ulong_t *)oaddr;
55			/* LINTED */
56			ulong_t *_iaddr = (ulong_t *)iaddr;
57
58			if (_iaddr)
59				*_oaddr = *_iaddr + reloc->r_value;
60			else
61				*_oaddr = reloc->r_value;
62		}
63		break;
64	default:
65		{
66			size_t re_fsize = reloc_table[rtype].re_fsize;
67
68			if (iaddr)
69				(void) memcpy(oaddr, iaddr, re_fsize);
70			else
71				(void) memset(oaddr, 0, re_fsize);
72		}
73	}
74}
75
76/*
77 * Copy a relocation record and increment its value.  The record must reflect
78 * the new address to which this image is fixed. Note that .got entries
79 * associated with .plt's must be fixed to the new base address.
80 */
81/* ARGSUSED3 */
82void
83inc_reloc(void *vnrel, void *vorel, Reloc *reloc, uchar_t *oaddr,
84    uchar_t *iaddr)
85{
86	Rela	*nrel = vnrel;
87	Rela	*orel = vorel;
88
89	if (ELF_R_TYPE(nrel->r_info, M_MACH) == R_AMD64_JUMP_SLOT) {
90		/* LINTED */
91		ulong_t	*_oaddr = (ulong_t *)oaddr;
92		/* LINTED */
93		ulong_t	*_iaddr = (ulong_t *)iaddr;
94
95		if (_iaddr)
96			*_oaddr = *_iaddr + reloc->r_value;
97		else
98			*_oaddr = reloc->r_value;
99	}
100
101	*nrel = *orel;
102	nrel->r_offset += reloc->r_value;
103}
104
105/*
106 * Clear a relocation record.  The relocation has been applied to the image and
107 * thus the relocation must not occur again.
108 */
109void
110clear_reloc(void *vrel)
111{
112	Rela	*rel = vrel;
113
114	rel->r_offset = 0;
115	rel->r_info = ELF_R_INFO(0, R_AMD64_NONE);
116	rel->r_addend = 0;
117}
118
119/*
120 * Apply a relocation to an image being built from an input file.  Use the
121 * runtime linkers routines to do the necessary magic.
122 */
123void
124apply_reloc(void *vrel, Reloc *reloc, const char *name, uchar_t *oaddr,
125    Rt_map *lmp)
126{
127	Rela	*rel = vrel;
128	Xword	type = ELF_R_TYPE(rel->r_info, M_MACH);
129	Xword	value = reloc->r_value + rel->r_addend;
130
131	if (type == R_AMD64_JUMP_SLOT) {
132		uintptr_t	addr, vaddr;
133
134		if (FLAGS(lmp) & FLG_RT_FIXED)
135			vaddr = 0;
136		else
137			vaddr = ADDR(lmp);
138
139		addr = (uintptr_t)oaddr - rel->r_offset;
140		/* LINTED */
141		(void) elf_plt_write((uintptr_t)addr, vaddr, rel,
142		    (uintptr_t)value, reloc->r_pltndx);
143
144	} else if (type == R_AMD64_COPY) {
145		(void) memcpy((void *)oaddr, (void *)value,
146		    (size_t)reloc->r_size);
147	} else {
148		(void) do_reloc_rtld(type, oaddr, &value, reloc->r_name, name,
149		    LIST(lmp));
150	}
151}
152