xref: /titanic_41/usr/src/uts/intel/ia32/krtld/doreloc.c (revision b6805bf78d2bbbeeaea8909a05623587b42d58b3)
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 (c) 1995, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 #if	defined(_KERNEL)
27 #include	<sys/types.h>
28 #include	"reloc.h"
29 #else
30 #define	ELF_TARGET_386
31 #if defined(DO_RELOC_LIBLD)
32 #undef DO_RELOC_LIBLD
33 #define	DO_RELOC_LIBLD_X86
34 #endif
35 #include	<stdio.h>
36 #include	"sgs.h"
37 #include	"machdep.h"
38 #include	"libld.h"
39 #include	"reloc.h"
40 #include	"conv.h"
41 #include	"msg.h"
42 #endif
43 
44 /*
45  * We need to build this code differently when it is used for
46  * cross linking:
47  *	- Data alignment requirements can differ from those
48  *		of the running system, so we can't access data
49  *		in units larger than a byte
50  *	- We have to include code to do byte swapping when the
51  *		target and linker host use different byte ordering,
52  *		but such code is a waste when running natively.
53  */
54 #if !defined(DO_RELOC_LIBLD) || defined(__i386) || defined(__amd64)
55 #define	DORELOC_NATIVE
56 #endif
57 
58 /*
59  * This table represents the current relocations that do_reloc() is able to
60  * process.  The relocations below that are marked SPECIAL are relocations that
61  * take special processing and shouldn't actually ever be passed to do_reloc().
62  */
63 const Rel_entry	reloc_table[R_386_NUM] = {
64 /* R_386_NONE */	{0, FLG_RE_NOTREL, 0, 0, 0},
65 /* R_386_32 */		{0, FLG_RE_NOTREL, 4, 0, 0},
66 /* R_386_PC32 */	{0, FLG_RE_PCREL, 4, 0, 0},
67 /* R_386_GOT32 */	{0, FLG_RE_GOTADD, 4, 0, 0},
68 /* R_386_PLT32 */	{0, FLG_RE_PLTREL | FLG_RE_PCREL, 4, 0, 0},
69 /* R_386_COPY */	{0, FLG_RE_NOTREL, 0, 0, 0},		/* SPECIAL */
70 /* R_386_GLOB_DAT */	{0, FLG_RE_NOTREL, 4, 0, 0},
71 /* R_386_JMP_SLOT */	{0, FLG_RE_NOTREL, 4, 0, 0},		/* SPECIAL */
72 /* R_386_RELATIVE */	{0, FLG_RE_NOTREL, 4, 0, 0},
73 /* R_386_GOTOFF */	{0, FLG_RE_GOTREL, 4, 0, 0},
74 /* R_386_GOTPC */	{0, FLG_RE_PCREL | FLG_RE_GOTPC | FLG_RE_LOCLBND, 4,
75 			    0, 0},
76 /* R_386_32PLT */	{0, FLG_RE_PLTREL, 4, 0, 0},
77 /* R_386_TLS_GD_PLT */	{0, FLG_RE_PLTREL | FLG_RE_PCREL | FLG_RE_TLSGD, 4,
78 			    0, 0},
79 /* R_386_TLS_LDM_PLT */	{0, FLG_RE_PLTREL | FLG_RE_PCREL | FLG_RE_TLSLD, 4,
80 			    0, 0},
81 /* R_386_TLS_TPOFF */	{0, FLG_RE_NOTREL, 4, 0, 0},
82 /* R_386_TLS_IE */	{0, FLG_RE_GOTADD | FLG_RE_TLSIE, 4, 0, 0},
83 /* R_386_TLS_GOTIE */	{0, FLG_RE_GOTADD | FLG_RE_TLSIE, 4, 0, 0},
84 /* R_386_TLS_LE */	{0, FLG_RE_TLSLE, 4, 0, 0},
85 /* R_386_TLS_GD */	{0, FLG_RE_GOTADD | FLG_RE_TLSGD, 4, 0, 0},
86 /* R_386_TLS_LDM */	{0, FLG_RE_GOTADD | FLG_RE_TLSLD, 4, 0, 0},
87 /* R_386_16 */		{0, FLG_RE_NOTREL, 2, 0, 0},
88 /* R_386_PC16 */	{0, FLG_RE_PCREL, 2, 0, 0},
89 /* R_386_8 */		{0, FLG_RE_NOTREL, 1, 0, 0},
90 /* R_386_PC8 */		{0, FLG_RE_PCREL, 1, 0, 0},
91 /* R_386_UNKNOWN24 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
92 /* R_386_UNKNOWN25 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
93 /* R_386_UNKNOWN26 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
94 /* R_386_UNKNOWN27 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
95 /* R_386_UNKNOWN28 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
96 /* R_386_UNKNOWN29 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
97 /* R_386_UNKNOWN30 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
98 /* R_386_UNKNOWN31 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
99 /* R_386_TLS_LDO_32 */	{0, FLG_RE_TLSLD, 4, 0, 0},
100 /* R_386_UNKNOWN33 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
101 /* R_386_UNKNOWN34 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
102 /* R_386_TLS_DTPMOD32 */ {0, FLG_RE_NOTREL, 4, 0, 0},
103 /* R_386_TLS_DTPOFF32 */ {0, FLG_RE_NOTREL, 4, 0, 0},
104 /* R_386_UNKONWN37 */	{0, FLG_RE_NOTSUP, 0, 0, 0},
105 /* R_386_SIZE32 */	{0, FLG_RE_SIZE | FLG_RE_VERIFY, 4, 0, 0}
106 };
107 
108 /*
109  * Write a single relocated value to its reference location.
110  * We assume we wish to add the relocation amount, value, to the
111  * value of the address already present at the offset.
112  *
113  * NAME			VALUE	FIELD		CALCULATION
114  *
115  * R_386_NONE		 0	none		none
116  * R_386_32		 1	word32		S + A
117  * R_386_PC32		 2	word32		S + A - P
118  * R_386_GOT32		 3	word32		G + A - P
119  * R_386_PLT32		 4	word32		L + A - P
120  * R_386_COPY		 5	none		none
121  * R_386_GLOB_DAT	 6	word32		S
122  * R_386_JMP_SLOT	 7	word32		S
123  * R_386_RELATIVE	 8	word32		B + A
124  * R_386_GOTOFF		 9	word32		S + A - GOT
125  * R_386_GOTPC		10	word32		GOT + A - P
126  * R_386_32PLT		11	word32		L + A
127  * R_386_TLS_GD_PLT	12	word32		@tlsgdplt
128  * R_386_TLS_LDM_PLT	13	word32		@tlsldmplt
129  * R_386_TLS_TPOFF	14	word32		@ntpoff(S)
130  * R_386_TLS_IE		15	word32		@indntpoff(S)
131  * R_386_TLS_GD		18	word32		@tlsgd(S)
132  * R_386_TLS_LDM	19	word32		@tlsldm(S)
133  * R_386_16		20	word16		S + A
134  * R_386_PC16		21	word16		S + A - P
135  * R_386_8		22	word8		S + A
136  * R_386_PC8		23	word8		S + A - P
137  * R_386_TLS_LDO_32	32	word32		@dtpoff(S)
138  * R_386_TLS_DTPMOD32	35	word32		@dtpmod(S)
139  * R_386_TLS_DTPOFF32	36	word32		@dtpoff(S)
140  * R_386_SIZE32		38	word32		Z + A
141  *
142  * Relocations 0-10 are from Figure 4-4: Relocation Types from the
143  * intel ABI.  Relocation 11 (R_386_32PLT) is from the C++ intel abi
144  * and is in the process of being registered with intel ABI (1/13/94).
145  *
146  * Relocations R_386_TLS_* are added to support Thread-Local storage
147  *	as recorded in PSARC/2001/509
148  *
149  * Relocation calculations:
150  *
151  * CALCULATION uses the following notation:
152  *	A	the addend used
153  *	B	the base address of the shared object in memory
154  *	G	the offset into the global offset table
155  *	GOT	the address of teh global offset table
156  *	L	the procedure linkage entry
157  *	P	the place of the storage unit being relocated
158  *	S	the value of the symbol
159  *	Z	the size of the symbol whose index resides in the relocation
160  *		entry
161  *
162  *	@dtlndx(x): Allocate two contiguous entries in the GOT table to hold
163  *	   a Tls_index structure (for passing to __tls_get_addr()). The
164  *	   instructions referencing this entry will be bound to the first
165  *	   of the two GOT entries.
166  *
167  *	@tmndx(x): Allocate two contiguous entries in the GOT table to hold
168  *	   a Tls_index structure (for passing to __tls_get_addr()). The
169  *	   ti_offset field of the Tls_index will be set to 0 (zero) and the
170  *	   ti_module will be filled in at run-time. The call to
171  *	   __tls_get_addr() will return the starting offset of the dynamic
172  *	   TLS block.
173  *
174  *	@dtpoff(x): calculate the tlsoffset relative to the TLS block.
175  *
176  *	@tpoff(x): calculate the tlsoffset relative to the TLS block.
177  *
178  *	@dtpmod(x): calculate the module id of the object containing symbol x.
179  *
180  * The calculations in the CALCULATION column are assumed to have
181  * been performed before calling this function except for the addition of
182  * the addresses in the instructions.
183  */
184 #if defined(_KERNEL)
185 #define	lml	0		/* Needed by arglist of REL_ERR_* macros */
186 int
187 do_reloc_krtld(uchar_t rtype, uchar_t *off, Xword *value, const char *sym,
188     const char *file)
189 #elif defined(DO_RELOC_LIBLD)
190 /*ARGSUSED5*/
191 int
192 do_reloc_ld(Rel_desc *rdesc, uchar_t *off, Xword *value,
193     rel_desc_sname_func_t rel_desc_sname_func,
194     const char *file, int bswap, void *lml)
195 #else
196 int
197 do_reloc_rtld(uchar_t rtype, uchar_t *off, Xword *value, const char *sym,
198     const char *file, void *lml)
199 #endif
200 {
201 #ifdef DO_RELOC_LIBLD
202 #define	sym (* rel_desc_sname_func)(rdesc)
203 	uchar_t	rtype = rdesc->rel_rtype;
204 #endif
205 	const Rel_entry	*rep;
206 
207 	rep = &reloc_table[rtype];
208 
209 	switch (rep->re_fsize) {
210 	case 1:
211 		/* LINTED */
212 		*((uchar_t *)off) += (uchar_t)(*value);
213 		break;
214 
215 	case 2:
216 #if defined(DORELOC_NATIVE)
217 		/* LINTED */
218 		*((Half *)off) += (Half)(*value);
219 #else
220 		{
221 			Half	v;
222 			uchar_t	*v_bytes = (uchar_t *)&v;
223 
224 			if (bswap) {
225 				UL_ASSIGN_BSWAP_HALF(v_bytes, off);
226 				v += *value;
227 				UL_ASSIGN_BSWAP_HALF(off, v_bytes);
228 			} else {
229 				UL_ASSIGN_HALF(v_bytes, off);
230 				v += *value;
231 				UL_ASSIGN_HALF(off, v_bytes);
232 			}
233 		}
234 #endif
235 		break;
236 
237 	case 4:
238 #if defined(DORELOC_NATIVE)
239 		/* LINTED */
240 		*((Xword *)off) += *value;
241 #else
242 		{
243 			Word	v;
244 			uchar_t	*v_bytes = (uchar_t *)&v;
245 
246 			if (bswap) {
247 				UL_ASSIGN_BSWAP_WORD(v_bytes, off);
248 				v += *value;
249 				UL_ASSIGN_BSWAP_WORD(off, v_bytes);
250 			} else {
251 				UL_ASSIGN_WORD(v_bytes, off);
252 				v += *value;
253 				UL_ASSIGN_WORD(off, v_bytes);
254 			}
255 		}
256 #endif
257 		break;
258 	default:
259 		/*
260 		 * To keep chkmsg() happy: MSG_INTL(MSG_REL_UNSUPSZ)
261 		 */
262 		REL_ERR_UNSUPSZ(lml, file, sym, rtype, rep->re_fsize);
263 		return (0);
264 	}
265 	return (1);
266 
267 #ifdef DO_RELOC_LIBLD
268 #undef sym
269 #endif
270 }
271