_relocate.c revision 1618:8c9a4f31d225 
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 2006 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26#pragma ident	"%Z%%M%	%I%	%E% SMI"
27
28#include	<string.h>
29#include	"machdep.h"
30#include	"reloc.h"
31#include	"_librtld.h"
32#include	"_elf.h"
33
34/*
35 * Undo relocations that have been applied to a memory image.  Basically this
36 * involves copying the original files relocation offset into the new image
37 * being created.
38 */
39/* ARGSUSED3 */
40void
41undo_reloc(void *vrel, uchar_t *oaddr, uchar_t *iaddr, Reloc *reloc)
42{
43	Rela		*rel = vrel;
44	const Rel_entry	*rep;
45	Xword		rtype = ELF_R_TYPE(rel->r_info);
46	ulong_t		*_oaddr;
47	ulong_t		*_iaddr;
48
49	switch (rtype) {
50	case R_SPARC_NONE:
51		break;
52	case R_SPARC_COPY:
53		(void) memset((void *)oaddr, 0, (size_t)reloc->r_size);
54		break;
55	case R_SPARC_JMP_SLOT:
56		/* LINTED */
57		_oaddr = (unsigned long *)oaddr;
58		/* LINTED */
59		_iaddr = (unsigned long *)iaddr;
60
61		if (_iaddr) {
62			*_oaddr++ = *_iaddr++;
63			*_oaddr++ = *_iaddr++;
64			*_oaddr = *_iaddr;
65		} else {
66			*_oaddr++ = 0;
67			*_oaddr++ = 0;
68			*_oaddr = 0;
69		}
70		break;
71	default:
72		rep = &reloc_table[rtype];
73		if (iaddr)
74			(void) memcpy(oaddr, iaddr, rep->re_fsize);
75		else
76			(void) memset(oaddr, 0, rep->re_fsize);
77	}
78}
79
80/*
81 * Copy a relocation record and increment its value.  The record must reflect
82 * the new address to which this image is fixed.
83 */
84/* ARGSUSED3 */
85void
86inc_reloc(void *vnrel, void *vorel, Reloc *reloc, uchar_t *oaddr,
87    uchar_t *iaddr)
88{
89	Rela	*nrel = vnrel;
90	Rela	*orel = vorel;
91
92	*nrel = *orel;
93	nrel->r_offset += reloc->r_value;
94}
95
96/*
97 * Clear a relocation record.  The relocation has been applied to the image and
98 * thus the relocation must not occur again.
99 */
100void
101clear_reloc(void *vrel)
102{
103	Rela	*rel = vrel;
104
105	rel->r_offset = 0;
106	rel->r_info = ELF_R_INFO(0, R_SPARC_NONE);
107	rel->r_addend = 0;
108}
109
110/*
111 * Apply a relocation to an image being built from an input file.  Use the
112 * runtime linkers routines to do the necessary magic.
113 */
114void
115apply_reloc(void *vrel, Reloc *reloc, const char *name, uchar_t *oaddr,
116    Rt_map *lmp)
117{
118	Rela	*rel = vrel;
119	Xword	type = ELF_R_TYPE(rel->r_info);
120	Xword	value = reloc->r_value + rel->r_addend;
121
122	if (type == R_SPARC_JMP_SLOT) {
123		uintptr_t	addr, vaddr;
124
125		if (FLAGS(lmp) & FLG_RT_FIXED)
126			vaddr = 0;
127		else
128			vaddr = ADDR(lmp);
129
130		addr = (uintptr_t)oaddr - rel->r_offset;
131		/* LINTED */
132		elf_plt_write((uintptr_t)addr, vaddr, rel,
133		    (uintptr_t)value, reloc->r_pltndx);
134
135	} else if (type == R_SPARC_COPY) {
136		(void) memcpy((void *)oaddr, (void *)value,
137		    (size_t)reloc->r_size);
138	} else {
139		if (IS_EXTOFFSET(type))
140			value += ELF_R_TYPE_DATA(rel->r_info);
141		(void) do_reloc(type, oaddr, &value, reloc->r_name, name,
142		    LIST(lmp));
143	}
144}
145