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 /*
27 * Copyright 2019 Joyent, Inc.
28 */
29
30 /*
31 * While this is no longer relevant to the kernel, we keep it in its
32 * traditional location to match the other variants, used from the ld
33 * code.
34 */
35
36 #define ELF_TARGET_386
37 #if defined(DO_RELOC_LIBLD)
38 #undef DO_RELOC_LIBLD
39 #define DO_RELOC_LIBLD_X86
40 #endif
41 #include <stdio.h>
42 #include "sgs.h"
43 #include "machdep.h"
44 #include "libld.h"
45 #include "reloc.h"
46 #include "conv.h"
47 #include "msg.h"
48
49 /*
50 * We need to build this code differently when it is used for
51 * cross linking:
52 * - Data alignment requirements can differ from those
53 * of the running system, so we can't access data
54 * in units larger than a byte
55 * - We have to include code to do byte swapping when the
56 * target and linker host use different byte ordering,
57 * but such code is a waste when running natively.
58 */
59 #if !defined(DO_RELOC_LIBLD) || defined(__x86)
60 #define DORELOC_NATIVE
61 #endif
62
63 /*
64 * This table represents the current relocations that do_reloc() is able to
65 * process. The relocations below that are marked SPECIAL are relocations that
66 * take special processing and shouldn't actually ever be passed to do_reloc().
67 */
68 const Rel_entry reloc_table[R_386_NUM] = {
69 [R_386_NONE] = {0, FLG_RE_NOTREL, 0, 0, 0},
70 [R_386_32] = {0, FLG_RE_NOTREL, 4, 0, 0},
71 [R_386_PC32] = {0, FLG_RE_PCREL, 4, 0, 0},
72 [R_386_GOT32] = {0, FLG_RE_GOTADD, 4, 0, 0},
73 [R_386_PLT32] = {0, FLG_RE_PLTREL | FLG_RE_PCREL, 4, 0, 0},
74 [R_386_COPY] = {0, FLG_RE_NOTREL, 0, 0, 0}, /* SPECIAL */
75 [R_386_GLOB_DAT] = {0, FLG_RE_NOTREL, 4, 0, 0},
76 [R_386_JMP_SLOT] = {0, FLG_RE_NOTREL, 4, 0, 0}, /* SPECIAL */
77 [R_386_RELATIVE] = {0, FLG_RE_NOTREL, 4, 0, 0},
78 [R_386_GOTOFF] = {0, FLG_RE_GOTREL, 4, 0, 0},
79 [R_386_GOTPC] = {0, FLG_RE_PCREL | FLG_RE_GOTPC |
80 FLG_RE_LOCLBND, 4, 0, 0},
81 [R_386_32PLT] = {0, FLG_RE_PLTREL, 4, 0, 0},
82 [R_386_TLS_GD_PLT] = {0, FLG_RE_PLTREL | FLG_RE_PCREL |
83 FLG_RE_TLSGD, 4, 0, 0},
84 [R_386_TLS_LDM_PLT] = {0, FLG_RE_PLTREL | FLG_RE_PCREL |
85 FLG_RE_TLSLD, 4, 0, 0},
86 [R_386_TLS_TPOFF] = {0, FLG_RE_NOTREL, 4, 0, 0},
87 [R_386_TLS_IE] = {0, FLG_RE_GOTADD | FLG_RE_TLSIE, 4, 0, 0},
88 [R_386_TLS_GOTIE] = {0, FLG_RE_GOTADD | FLG_RE_TLSIE, 4, 0, 0},
89 [R_386_TLS_LE] = {0, FLG_RE_TLSLE, 4, 0, 0},
90 [R_386_TLS_GD] = {0, FLG_RE_GOTADD | FLG_RE_TLSGD, 4, 0, 0},
91 [R_386_TLS_LDM] = {0, FLG_RE_GOTADD | FLG_RE_TLSLD, 4, 0, 0},
92 [R_386_16] = {0, FLG_RE_NOTREL, 2, 0, 0},
93 [R_386_PC16] = {0, FLG_RE_PCREL, 2, 0, 0},
94 [R_386_8] = {0, FLG_RE_NOTREL, 1, 0, 0},
95 [R_386_PC8] = {0, FLG_RE_PCREL, 1, 0, 0},
96 [R_386_TLS_GD_32] = {0, FLG_RE_NOTSUP, 0, 0, 0},
97 [R_386_TLS_GD_PUSH] = {0, FLG_RE_NOTSUP, 0, 0, 0},
98 [R_386_TLS_GD_CALL] = {0, FLG_RE_NOTSUP, 0, 0, 0},
99 [R_386_TLS_GD_POP] = {0, FLG_RE_NOTSUP, 0, 0, 0},
100 [R_386_TLS_LDM_32] = {0, FLG_RE_NOTSUP, 0, 0, 0},
101 [R_386_TLS_LDM_PUSH] = {0, FLG_RE_NOTSUP, 0, 0, 0},
102 [R_386_TLS_LDM_CALL] = {0, FLG_RE_NOTSUP, 0, 0, 0},
103 [R_386_TLS_LDM_POP] = {0, FLG_RE_NOTSUP, 0, 0, 0},
104 [R_386_TLS_LDO_32] = {0, FLG_RE_TLSLD, 4, 0, 0},
105 [R_386_TLS_IE_32] = {0, FLG_RE_NOTSUP, 0, 0, 0},
106 [R_386_TLS_LE_32] = {0, FLG_RE_NOTSUP, 0, 0, 0},
107 [R_386_TLS_DTPMOD32] = {0, FLG_RE_NOTREL, 4, 0, 0},
108 [R_386_TLS_DTPOFF32] = {0, FLG_RE_NOTREL, 4, 0, 0},
109 [R_386_TLS_TPOFF32] = {0, FLG_RE_NOTSUP, 0, 0, 0},
110 [R_386_SIZE32] = {0, FLG_RE_SIZE | FLG_RE_VERIFY, 4, 0, 0},
111 [R_386_TLS_GOTDESC] = {0, FLG_RE_NOTSUP, 0, 0, 0},
112 [R_386_TLS_DESC_CALL] = {0, FLG_RE_NOTSUP, 0, 0, 0},
113 [R_386_TLS_DESC] = {0, FLG_RE_NOTSUP, 0, 0, 0},
114 [R_386_IRELATIVE] = {0, FLG_RE_NOTSUP, 0, 0, 0},
115 [R_386_GOT32X] = {0, FLG_RE_GOTADD, 4, 0, 0},
116 };
117 #if (R_386_NUM != (R_386_GOT32X + 1))
118 #error "R_386_NUM has grown"
119 #endif
120
121 /*
122 * Write a single relocated value to its reference location.
123 * We assume we wish to add the relocation amount, value, to the
124 * value of the address already present at the offset.
125 *
126 * NAME VALUE FIELD CALCULATION
127 *
128 * R_386_NONE 0 none none
129 * R_386_32 1 word32 S + A
130 * R_386_PC32 2 word32 S + A - P
131 * R_386_GOT32 3 word32 G + A - GOT / G + A
132 * R_386_PLT32 4 word32 L + A - P
133 * R_386_COPY 5 none none
134 * R_386_GLOB_DAT 6 word32 S
135 * R_386_JMP_SLOT 7 word32 S
136 * R_386_RELATIVE 8 word32 B + A
137 * R_386_GOTOFF 9 word32 S + A - GOT
138 * R_386_GOTPC 10 word32 GOT + A - P
139 * R_386_32PLT 11 word32 L + A
140 * R_386_TLS_GD_PLT 12 word32 @tlsgdplt
141 * R_386_TLS_LDM_PLT 13 word32 @tlsldmplt
142 * R_386_TLS_TPOFF 14 word32 @ntpoff(S)
143 * R_386_TLS_IE 15 word32 @indntpoff(S)
144 * R_386_TLS_GOTIE 16 word32 @gotntpoff(S)
145 * R_386_TLS_LE 17 word32 @ntpoff(S)
146 * R_386_TLS_GD 18 word32 @tlsgd(S)
147 * R_386_TLS_LDM 19 word32 @tlsldm(S)
148 * R_386_16 20 word16 S + A
149 * R_386_PC16 21 word16 S + A - P
150 * R_386_8 22 word8 S + A
151 * R_386_PC8 23 word8 S + A - P
152 * R_386_TLS_GD_32 24 word32
153 * R_386_TLS_GD_PUSH 25 word32
154 * R_386_TLS_GD_CALL 26 word32
155 * R_386_TLS_GD_POP 27 word32
156 * R_386_TLS_LDM_32 28 word32
157 * R_386_TLS_LDM_PUSH 29 word32
158 * R_386_TLS_LDM_CALL 30 word32
159 * R_386_TLS_LDM_POP 31 word32
160 * R_386_TLS_LDO_32 32 word32 @dtpoff(S)
161 * R_386_TLS_IE_32 33 word32 @gotpoff(S)
162 * R_386_TLS_LE_32 34 word32 @tpoff(S)
163 * R_386_TLS_DTPMOD32 35 word32 @dtpmod(S)
164 * R_386_TLS_DTPOFF32 36 word32 @dtpoff(S)
165 * R_386_TLS_TPOFF32 37 word32
166 * R_386_SIZE32 38 word32 Z + A
167 * R_386_TLS_GOTDESC 39 word32
168 * R_386_TLS_DESC_CALL 40 none none
169 * R_386_TLS_DESC 41 word32
170 * R_386_IRELATIVE 42 word32 indirect (B + A)
171 * R_386_GOT32X 43 word32 G + A - GOT / G + A
172 *
173 * Relocations are from Table 3.6: Relocation Types from the 386 psABI.
174 * (with reference also to the thread-local storage ABIs)
175 *
176 * Relocation calculations:
177 *
178 * CALCULATION uses the following notation:
179 * A the addend used
180 * B the base address of the shared object in memory
181 * G the offset into the global offset table
182 * GOT the address of teh global offset table
183 * L the procedure linkage entry
184 * P the place of the storage unit being relocated
185 * S the value of the symbol
186 * Z the size of the symbol whose index resides in the relocation
187 * entry
188 *
189 * @dtlndx(x): Allocate two contiguous entries in the GOT table to hold
190 * a Tls_index structure (for passing to __tls_get_addr()). The
191 * instructions referencing this entry will be bound to the first
192 * of the two GOT entries.
193 *
194 * @tmndx(x): Allocate two contiguous entries in the GOT table to hold
195 * a Tls_index structure (for passing to __tls_get_addr()). The
196 * ti_offset field of the Tls_index will be set to 0 (zero) and the
197 * ti_module will be filled in at run-time. The call to
198 * __tls_get_addr() will return the starting offset of the dynamic
199 * TLS block.
200 *
201 * @dtpoff(x): calculate the tlsoffset relative to the TLS block.
202 *
203 * @tpoff(x): calculate the tlsoffset relative to the TLS block.
204 *
205 * @dtpmod(x): calculate the module id of the object containing symbol x.
206 *
207 * The calculations in the CALCULATION column are assumed to have
208 * been performed before calling this function except for the addition of
209 * the addresses in the instructions.
210 */
211 /* BEGIN CSTYLED */
212 #if defined(DO_RELOC_LIBLD)
213 /*ARGSUSED5*/
214 int
do_reloc_ld(Rel_desc * rdesc,uchar_t * off,Xword * value,rel_desc_sname_func_t rel_desc_sname_func,const char * file,int bswap,void * lml)215 do_reloc_ld(Rel_desc *rdesc, uchar_t *off, Xword *value,
216 rel_desc_sname_func_t rel_desc_sname_func,
217 const char *file, int bswap, void *lml)
218 #else
219 int
220 do_reloc_rtld(uchar_t rtype, uchar_t *off, Xword *value, const char *sym,
221 const char *file, void *lml)
222 #endif
223 {
224 /* END CSTYLED */
225 #ifdef DO_RELOC_LIBLD
226 #define sym (* rel_desc_sname_func)(rdesc)
227 uchar_t rtype = rdesc->rel_rtype;
228 #endif
229 const Rel_entry *rep;
230
231 rep = &reloc_table[rtype];
232
233 switch (rep->re_fsize) {
234 case 1:
235 /* LINTED */
236 *((uchar_t *)off) += (uchar_t)(*value);
237 break;
238
239 case 2:
240 #if defined(DORELOC_NATIVE)
241 /* LINTED */
242 *((Half *)off) += (Half)(*value);
243 #else
244 {
245 Half v;
246 uchar_t *v_bytes = (uchar_t *)&v;
247
248 if (bswap) {
249 UL_ASSIGN_BSWAP_HALF(v_bytes, off);
250 v += *value;
251 UL_ASSIGN_BSWAP_HALF(off, v_bytes);
252 } else {
253 UL_ASSIGN_HALF(v_bytes, off);
254 v += *value;
255 UL_ASSIGN_HALF(off, v_bytes);
256 }
257 }
258 #endif
259 break;
260
261 case 4:
262 #if defined(DORELOC_NATIVE)
263 /* LINTED */
264 *((Xword *)off) += *value;
265 #else
266 {
267 Word v;
268 uchar_t *v_bytes = (uchar_t *)&v;
269
270 if (bswap) {
271 UL_ASSIGN_BSWAP_WORD(v_bytes, off);
272 v += *value;
273 UL_ASSIGN_BSWAP_WORD(off, v_bytes);
274 } else {
275 UL_ASSIGN_WORD(v_bytes, off);
276 v += *value;
277 UL_ASSIGN_WORD(off, v_bytes);
278 }
279 }
280 #endif
281 break;
282 default:
283 /*
284 * To keep chkmsg() happy: MSG_INTL(MSG_REL_UNSUPSZ)
285 */
286 REL_ERR_UNSUPSZ(lml, file, sym, rtype, rep->re_fsize);
287 return (0);
288 }
289 return (1);
290
291 #ifdef DO_RELOC_LIBLD
292 #undef sym
293 #endif
294 }
295