mdreloc.c revision 1.46 1 1.46 christos /* $NetBSD: mdreloc.c,v 1.46 2010/01/13 20:17:22 christos Exp $ */
2 1.1 eeh
3 1.1 eeh /*-
4 1.1 eeh * Copyright (c) 2000 Eduardo Horvath.
5 1.23 mycroft * Copyright (c) 1999, 2002 The NetBSD Foundation, Inc.
6 1.1 eeh * All rights reserved.
7 1.1 eeh *
8 1.1 eeh * This code is derived from software contributed to The NetBSD Foundation
9 1.27 mycroft * by Paul Kranenburg and by Charles M. Hannum.
10 1.1 eeh *
11 1.1 eeh * Redistribution and use in source and binary forms, with or without
12 1.1 eeh * modification, are permitted provided that the following conditions
13 1.1 eeh * are met:
14 1.1 eeh * 1. Redistributions of source code must retain the above copyright
15 1.1 eeh * notice, this list of conditions and the following disclaimer.
16 1.1 eeh * 2. Redistributions in binary form must reproduce the above copyright
17 1.1 eeh * notice, this list of conditions and the following disclaimer in the
18 1.1 eeh * documentation and/or other materials provided with the distribution.
19 1.1 eeh *
20 1.1 eeh * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 1.1 eeh * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 1.1 eeh * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 1.1 eeh * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 1.1 eeh * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 1.1 eeh * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 1.1 eeh * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 1.1 eeh * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 1.1 eeh * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 1.1 eeh * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 1.1 eeh * POSSIBILITY OF SUCH DAMAGE.
31 1.1 eeh */
32 1.1 eeh
33 1.37 skrll #include <sys/cdefs.h>
34 1.37 skrll #ifndef lint
35 1.46 christos __RCSID("$NetBSD: mdreloc.c,v 1.46 2010/01/13 20:17:22 christos Exp $");
36 1.37 skrll #endif /* not lint */
37 1.37 skrll
38 1.1 eeh #include <errno.h>
39 1.1 eeh #include <stdio.h>
40 1.1 eeh #include <stdlib.h>
41 1.1 eeh #include <string.h>
42 1.1 eeh #include <unistd.h>
43 1.1 eeh #include <sys/stat.h>
44 1.1 eeh
45 1.1 eeh #include "rtldenv.h"
46 1.1 eeh #include "debug.h"
47 1.1 eeh #include "rtld.h"
48 1.1 eeh
49 1.1 eeh /*
50 1.1 eeh * The following table holds for each relocation type:
51 1.1 eeh * - the width in bits of the memory location the relocation
52 1.1 eeh * applies to (not currently used)
53 1.1 eeh * - the number of bits the relocation value must be shifted to the
54 1.1 eeh * right (i.e. discard least significant bits) to fit into
55 1.1 eeh * the appropriate field in the instruction word.
56 1.1 eeh * - flags indicating whether
57 1.1 eeh * * the relocation involves a symbol
58 1.1 eeh * * the relocation is relative to the current position
59 1.1 eeh * * the relocation is for a GOT entry
60 1.1 eeh * * the relocation is relative to the load address
61 1.1 eeh *
62 1.1 eeh */
63 1.1 eeh #define _RF_S 0x80000000 /* Resolve symbol */
64 1.1 eeh #define _RF_A 0x40000000 /* Use addend */
65 1.1 eeh #define _RF_P 0x20000000 /* Location relative */
66 1.1 eeh #define _RF_G 0x10000000 /* GOT offset */
67 1.1 eeh #define _RF_B 0x08000000 /* Load address relative */
68 1.2 eeh #define _RF_U 0x04000000 /* Unaligned */
69 1.1 eeh #define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */
70 1.1 eeh #define _RF_RS(s) ( (s) & 0xff) /* right shift */
71 1.16 mycroft static const int reloc_target_flags[] = {
72 1.1 eeh 0, /* NONE */
73 1.1 eeh _RF_S|_RF_A| _RF_SZ(8) | _RF_RS(0), /* RELOC_8 */
74 1.1 eeh _RF_S|_RF_A| _RF_SZ(16) | _RF_RS(0), /* RELOC_16 */
75 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* RELOC_32 */
76 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(8) | _RF_RS(0), /* DISP_8 */
77 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(16) | _RF_RS(0), /* DISP_16 */
78 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* DISP_32 */
79 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_30 */
80 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_22 */
81 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HI22 */
82 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 22 */
83 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 13 */
84 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LO10 */
85 1.1 eeh _RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT10 */
86 1.1 eeh _RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT13 */
87 1.1 eeh _RF_G| _RF_SZ(32) | _RF_RS(10), /* GOT22 */
88 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PC10 */
89 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC22 */
90 1.1 eeh _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WPLT30 */
91 1.1 eeh _RF_SZ(32) | _RF_RS(0), /* COPY */
92 1.1 eeh _RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* GLOB_DAT */
93 1.1 eeh _RF_SZ(32) | _RF_RS(0), /* JMP_SLOT */
94 1.1 eeh _RF_A| _RF_B| _RF_SZ(64) | _RF_RS(0), /* RELATIVE */
95 1.2 eeh _RF_S|_RF_A| _RF_U| _RF_SZ(32) | _RF_RS(0), /* UA_32 */
96 1.1 eeh
97 1.1 eeh _RF_A| _RF_SZ(32) | _RF_RS(0), /* PLT32 */
98 1.1 eeh _RF_A| _RF_SZ(32) | _RF_RS(10), /* HIPLT22 */
99 1.1 eeh _RF_A| _RF_SZ(32) | _RF_RS(0), /* LOPLT10 */
100 1.1 eeh _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT32 */
101 1.1 eeh _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PCPLT22 */
102 1.1 eeh _RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PCPLT10 */
103 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 10 */
104 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 11 */
105 1.1 eeh _RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* 64 */
106 1.1 eeh _RF_S|_RF_A|/*extra*/ _RF_SZ(32) | _RF_RS(0), /* OLO10 */
107 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(42), /* HH22 */
108 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(32), /* HM10 */
109 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* LM22 */
110 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(42), /* PC_HH22 */
111 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(32), /* PC_HM10 */
112 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC_LM22 */
113 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP16 */
114 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP19 */
115 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* GLOB_JMP */
116 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 7 */
117 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 5 */
118 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 6 */
119 1.1 eeh _RF_S|_RF_A|_RF_P| _RF_SZ(64) | _RF_RS(0), /* DISP64 */
120 1.1 eeh _RF_A| _RF_SZ(64) | _RF_RS(0), /* PLT64 */
121 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HIX22 */
122 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LOX10 */
123 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(22), /* H44 */
124 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(12), /* M44 */
125 1.1 eeh _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* L44 */
126 1.1 eeh _RF_S|_RF_A| _RF_SZ(64) | _RF_RS(0), /* REGISTER */
127 1.2 eeh _RF_S|_RF_A| _RF_U| _RF_SZ(64) | _RF_RS(0), /* UA64 */
128 1.2 eeh _RF_S|_RF_A| _RF_U| _RF_SZ(16) | _RF_RS(0), /* UA16 */
129 1.1 eeh };
130 1.1 eeh
131 1.1 eeh #ifdef RTLD_DEBUG_RELOC
132 1.1 eeh static const char *reloc_names[] = {
133 1.1 eeh "NONE", "RELOC_8", "RELOC_16", "RELOC_32", "DISP_8",
134 1.1 eeh "DISP_16", "DISP_32", "WDISP_30", "WDISP_22", "HI22",
135 1.1 eeh "22", "13", "LO10", "GOT10", "GOT13",
136 1.1 eeh "GOT22", "PC10", "PC22", "WPLT30", "COPY",
137 1.1 eeh "GLOB_DAT", "JMP_SLOT", "RELATIVE", "UA_32", "PLT32",
138 1.1 eeh "HIPLT22", "LOPLT10", "LOPLT10", "PCPLT22", "PCPLT32",
139 1.1 eeh "10", "11", "64", "OLO10", "HH22",
140 1.1 eeh "HM10", "LM22", "PC_HH22", "PC_HM10", "PC_LM22",
141 1.1 eeh "WDISP16", "WDISP19", "GLOB_JMP", "7", "5", "6",
142 1.1 eeh "DISP64", "PLT64", "HIX22", "LOX10", "H44", "M44",
143 1.1 eeh "L44", "REGISTER", "UA64", "UA16"
144 1.1 eeh };
145 1.1 eeh #endif
146 1.1 eeh
147 1.1 eeh #define RELOC_RESOLVE_SYMBOL(t) ((reloc_target_flags[t] & _RF_S) != 0)
148 1.1 eeh #define RELOC_PC_RELATIVE(t) ((reloc_target_flags[t] & _RF_P) != 0)
149 1.1 eeh #define RELOC_BASE_RELATIVE(t) ((reloc_target_flags[t] & _RF_B) != 0)
150 1.2 eeh #define RELOC_UNALIGNED(t) ((reloc_target_flags[t] & _RF_U) != 0)
151 1.2 eeh #define RELOC_USE_ADDEND(t) ((reloc_target_flags[t] & _RF_A) != 0)
152 1.1 eeh #define RELOC_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff)
153 1.1 eeh #define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff)
154 1.1 eeh
155 1.16 mycroft static const long reloc_target_bitmask[] = {
156 1.1 eeh #define _BM(x) (~(-(1ULL << (x))))
157 1.1 eeh 0, /* NONE */
158 1.1 eeh _BM(8), _BM(16), _BM(32), /* RELOC_8, _16, _32 */
159 1.1 eeh _BM(8), _BM(16), _BM(32), /* DISP8, DISP16, DISP32 */
160 1.1 eeh _BM(30), _BM(22), /* WDISP30, WDISP22 */
161 1.1 eeh _BM(22), _BM(22), /* HI22, _22 */
162 1.1 eeh _BM(13), _BM(10), /* RELOC_13, _LO10 */
163 1.1 eeh _BM(10), _BM(13), _BM(22), /* GOT10, GOT13, GOT22 */
164 1.1 eeh _BM(10), _BM(22), /* _PC10, _PC22 */
165 1.1 eeh _BM(30), 0, /* _WPLT30, _COPY */
166 1.1 eeh _BM(32), _BM(32), _BM(32), /* _GLOB_DAT, JMP_SLOT, _RELATIVE */
167 1.1 eeh _BM(32), _BM(32), /* _UA32, PLT32 */
168 1.1 eeh _BM(22), _BM(10), /* _HIPLT22, LOPLT10 */
169 1.1 eeh _BM(32), _BM(22), _BM(10), /* _PCPLT32, _PCPLT22, _PCPLT10 */
170 1.1 eeh _BM(10), _BM(11), -1, /* _10, _11, _64 */
171 1.1 eeh _BM(10), _BM(22), /* _OLO10, _HH22 */
172 1.1 eeh _BM(10), _BM(22), /* _HM10, _LM22 */
173 1.1 eeh _BM(22), _BM(10), _BM(22), /* _PC_HH22, _PC_HM10, _PC_LM22 */
174 1.1 eeh _BM(16), _BM(19), /* _WDISP16, _WDISP19 */
175 1.1 eeh -1, /* GLOB_JMP */
176 1.1 eeh _BM(7), _BM(5), _BM(6) /* _7, _5, _6 */
177 1.1 eeh -1, -1, /* DISP64, PLT64 */
178 1.1 eeh _BM(22), _BM(13), /* HIX22, LOX10 */
179 1.1 eeh _BM(22), _BM(10), _BM(13), /* H44, M44, L44 */
180 1.1 eeh -1, -1, _BM(16), /* REGISTER, UA64, UA16 */
181 1.1 eeh #undef _BM
182 1.1 eeh };
183 1.1 eeh #define RELOC_VALUE_BITMASK(t) (reloc_target_bitmask[t])
184 1.1 eeh
185 1.1 eeh /*
186 1.1 eeh * Instruction templates:
187 1.1 eeh */
188 1.1 eeh #define BAA 0x10400000 /* ba,a %xcc, 0 */
189 1.1 eeh #define SETHI 0x03000000 /* sethi %hi(0), %g1 */
190 1.1 eeh #define JMP 0x81c06000 /* jmpl %g1+%lo(0), %g0 */
191 1.1 eeh #define NOP 0x01000000 /* sethi %hi(0), %g0 */
192 1.1 eeh #define OR 0x82806000 /* or %g1, 0, %g1 */
193 1.1 eeh #define XOR 0x82c06000 /* xor %g1, 0, %g1 */
194 1.1 eeh #define MOV71 0x8283a000 /* or %o7, 0, %g1 */
195 1.1 eeh #define MOV17 0x9c806000 /* or %g1, 0, %o7 */
196 1.1 eeh #define CALL 0x40000000 /* call 0 */
197 1.1 eeh #define SLLX 0x8b407000 /* sllx %g1, 0, %g1 */
198 1.1 eeh #define SETHIG5 0x0b000000 /* sethi %hi(0), %g5 */
199 1.1 eeh #define ORG5 0x82804005 /* or %g1, %g5, %g1 */
200 1.1 eeh
201 1.1 eeh
202 1.26 mycroft /* %hi(v)/%lo(v) with variable shift */
203 1.26 mycroft #define HIVAL(v, s) (((v) >> (s)) & 0x003fffff)
204 1.26 mycroft #define LOVAL(v, s) (((v) >> (s)) & 0x000003ff)
205 1.1 eeh
206 1.20 mycroft void _rtld_bind_start_0(long, long);
207 1.20 mycroft void _rtld_bind_start_1(long, long);
208 1.18 mycroft void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
209 1.34 skrll caddr_t _rtld_bind(const Obj_Entry *, Elf_Word);
210 1.1 eeh
211 1.1 eeh /*
212 1.1 eeh * Install rtld function call into this PLT slot.
213 1.1 eeh */
214 1.29 mycroft #define SAVE 0x9de3bf50 /* i.e. `save %sp,-176,%sp' */
215 1.1 eeh #define SETHI_l0 0x21000000
216 1.1 eeh #define SETHI_l1 0x23000000
217 1.1 eeh #define OR_l0_l0 0xa0142000
218 1.1 eeh #define SLLX_l0_32_l0 0xa12c3020
219 1.1 eeh #define OR_l0_l1_l0 0xa0140011
220 1.26 mycroft #define JMPL_l0_o0 0x91c42000
221 1.26 mycroft #define MOV_g1_o1 0x92100001
222 1.1 eeh
223 1.36 skrll void _rtld_install_plt(Elf_Word *, Elf_Addr);
224 1.36 skrll static inline int _rtld_relocate_plt_object(const Obj_Entry *,
225 1.36 skrll const Elf_Rela *, Elf_Addr *);
226 1.1 eeh
227 1.1 eeh void
228 1.34 skrll _rtld_install_plt(Elf_Word *pltgot, Elf_Addr proc)
229 1.1 eeh {
230 1.1 eeh pltgot[0] = SAVE;
231 1.1 eeh pltgot[1] = SETHI_l0 | HIVAL(proc, 42);
232 1.1 eeh pltgot[2] = SETHI_l1 | HIVAL(proc, 10);
233 1.26 mycroft pltgot[3] = OR_l0_l0 | LOVAL(proc, 32);
234 1.1 eeh pltgot[4] = SLLX_l0_32_l0;
235 1.1 eeh pltgot[5] = OR_l0_l1_l0;
236 1.26 mycroft pltgot[6] = JMPL_l0_o0 | LOVAL(proc, 0);
237 1.26 mycroft pltgot[7] = MOV_g1_o1;
238 1.1 eeh }
239 1.2 eeh
240 1.6 mycroft void
241 1.6 mycroft _rtld_setup_pltgot(const Obj_Entry *obj)
242 1.6 mycroft {
243 1.6 mycroft /*
244 1.6 mycroft * On sparc64 we got troubles.
245 1.6 mycroft *
246 1.6 mycroft * Instructions are 4 bytes long.
247 1.6 mycroft * Elf[64]_Addr is 8 bytes long, so are our pltglot[]
248 1.6 mycroft * array entries.
249 1.6 mycroft * Each PLT entry jumps to PLT0 to enter the dynamic
250 1.6 mycroft * linker.
251 1.6 mycroft * Loading an arbitrary 64-bit pointer takes 6
252 1.6 mycroft * instructions and 2 registers.
253 1.6 mycroft *
254 1.6 mycroft * Somehow we need to issue a save to get a new stack
255 1.6 mycroft * frame, load the address of the dynamic linker, and
256 1.6 mycroft * jump there, in 8 instructions or less.
257 1.6 mycroft *
258 1.6 mycroft * Oh, we need to fill out both PLT0 and PLT1.
259 1.6 mycroft */
260 1.6 mycroft {
261 1.6 mycroft Elf_Word *entry = (Elf_Word *)obj->pltgot;
262 1.6 mycroft
263 1.6 mycroft /* Install in entries 0 and 1 */
264 1.6 mycroft _rtld_install_plt(&entry[0], (Elf_Addr) &_rtld_bind_start_0);
265 1.6 mycroft _rtld_install_plt(&entry[8], (Elf_Addr) &_rtld_bind_start_1);
266 1.6 mycroft
267 1.6 mycroft /*
268 1.6 mycroft * Install the object reference in first slot
269 1.6 mycroft * of entry 2.
270 1.6 mycroft */
271 1.6 mycroft obj->pltgot[8] = (Elf_Addr) obj;
272 1.6 mycroft }
273 1.8 mycroft }
274 1.8 mycroft
275 1.18 mycroft void
276 1.34 skrll _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
277 1.18 mycroft {
278 1.18 mycroft const Elf_Rela *rela = 0, *relalim;
279 1.18 mycroft Elf_Addr relasz = 0;
280 1.18 mycroft Elf_Addr *where;
281 1.18 mycroft
282 1.18 mycroft for (; dynp->d_tag != DT_NULL; dynp++) {
283 1.18 mycroft switch (dynp->d_tag) {
284 1.18 mycroft case DT_RELA:
285 1.18 mycroft rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
286 1.18 mycroft break;
287 1.18 mycroft case DT_RELASZ:
288 1.18 mycroft relasz = dynp->d_un.d_val;
289 1.18 mycroft break;
290 1.18 mycroft }
291 1.18 mycroft }
292 1.44 lukem relalim = (const Elf_Rela *)((const uint8_t *)rela + relasz);
293 1.18 mycroft for (; rela < relalim; rela++) {
294 1.18 mycroft where = (Elf_Addr *)(relocbase + rela->r_offset);
295 1.18 mycroft *where = (Elf_Addr)(relocbase + rela->r_addend);
296 1.18 mycroft }
297 1.18 mycroft }
298 1.18 mycroft
299 1.8 mycroft int
300 1.34 skrll _rtld_relocate_nonplt_objects(const Obj_Entry *obj)
301 1.8 mycroft {
302 1.9 mycroft const Elf_Rela *rela;
303 1.40 martin const Elf_Sym *def = NULL;
304 1.40 martin const Obj_Entry *defobj = NULL;
305 1.18 mycroft
306 1.9 mycroft for (rela = obj->rela; rela < obj->relalim; rela++) {
307 1.9 mycroft Elf_Addr *where;
308 1.9 mycroft Elf_Word type;
309 1.9 mycroft Elf_Addr value = 0, mask;
310 1.10 mycroft unsigned long symnum;
311 1.9 mycroft
312 1.9 mycroft where = (Elf_Addr *) (obj->relocbase + rela->r_offset);
313 1.10 mycroft symnum = ELF_R_SYM(rela->r_info);
314 1.9 mycroft
315 1.9 mycroft type = ELF_R_TYPE(rela->r_info);
316 1.9 mycroft if (type == R_TYPE(NONE))
317 1.12 mycroft continue;
318 1.9 mycroft
319 1.23 mycroft /* We do JMP_SLOTs in _rtld_bind() below */
320 1.9 mycroft if (type == R_TYPE(JMP_SLOT))
321 1.12 mycroft continue;
322 1.9 mycroft
323 1.9 mycroft /* COPY relocs are also handled elsewhere */
324 1.9 mycroft if (type == R_TYPE(COPY))
325 1.12 mycroft continue;
326 1.8 mycroft
327 1.9 mycroft /*
328 1.9 mycroft * We use the fact that relocation types are an `enum'
329 1.9 mycroft * Note: R_SPARC_UA16 is currently numerically largest.
330 1.9 mycroft */
331 1.9 mycroft if (type > R_TYPE(UA16))
332 1.9 mycroft return (-1);
333 1.8 mycroft
334 1.9 mycroft value = rela->r_addend;
335 1.8 mycroft
336 1.9 mycroft /*
337 1.18 mycroft * Handle relative relocs here, as an optimization.
338 1.9 mycroft */
339 1.17 mycroft if (type == R_TYPE(RELATIVE)) {
340 1.9 mycroft *where = (Elf_Addr)(obj->relocbase + value);
341 1.21 mycroft rdbg(("RELATIVE in %s --> %p", obj->path,
342 1.18 mycroft (void *)*where));
343 1.12 mycroft continue;
344 1.9 mycroft }
345 1.8 mycroft
346 1.9 mycroft if (RELOC_RESOLVE_SYMBOL(type)) {
347 1.8 mycroft
348 1.9 mycroft /* Find the symbol */
349 1.41 matt def = _rtld_find_symdef(symnum, obj, &defobj,
350 1.41 matt false);
351 1.41 matt if (def == NULL)
352 1.41 matt return -1;
353 1.8 mycroft
354 1.9 mycroft /* Add in the symbol's absolute address */
355 1.9 mycroft value += (Elf_Addr)(defobj->relocbase + def->st_value);
356 1.9 mycroft }
357 1.8 mycroft
358 1.9 mycroft if (RELOC_PC_RELATIVE(type)) {
359 1.9 mycroft value -= (Elf_Addr)where;
360 1.9 mycroft }
361 1.8 mycroft
362 1.9 mycroft if (RELOC_BASE_RELATIVE(type)) {
363 1.9 mycroft /*
364 1.9 mycroft * Note that even though sparcs use `Elf_rela'
365 1.9 mycroft * exclusively we still need the implicit memory addend
366 1.9 mycroft * in relocations referring to GOT entries.
367 1.9 mycroft * Undoubtedly, someone f*cked this up in the distant
368 1.9 mycroft * past, and now we're stuck with it in the name of
369 1.9 mycroft * compatibility for all eternity..
370 1.9 mycroft *
371 1.9 mycroft * In any case, the implicit and explicit should be
372 1.9 mycroft * mutually exclusive. We provide a check for that
373 1.9 mycroft * here.
374 1.9 mycroft */
375 1.8 mycroft #ifdef DIAGNOSTIC
376 1.9 mycroft if (value != 0 && *where != 0) {
377 1.9 mycroft xprintf("BASE_REL(%s): where=%p, *where 0x%lx, "
378 1.9 mycroft "addend=0x%lx, base %p\n",
379 1.9 mycroft obj->path, where, *where,
380 1.9 mycroft rela->r_addend, obj->relocbase);
381 1.9 mycroft }
382 1.9 mycroft #endif
383 1.9 mycroft /* XXXX -- apparently we ignore the preexisting value */
384 1.9 mycroft value += (Elf_Addr)(obj->relocbase);
385 1.8 mycroft }
386 1.8 mycroft
387 1.9 mycroft mask = RELOC_VALUE_BITMASK(type);
388 1.9 mycroft value >>= RELOC_VALUE_RIGHTSHIFT(type);
389 1.9 mycroft value &= mask;
390 1.9 mycroft
391 1.9 mycroft if (RELOC_UNALIGNED(type)) {
392 1.9 mycroft /* Handle unaligned relocations. */
393 1.9 mycroft Elf_Addr tmp = 0;
394 1.9 mycroft char *ptr = (char *)where;
395 1.9 mycroft int i, size = RELOC_TARGET_SIZE(type)/8;
396 1.9 mycroft
397 1.9 mycroft /* Read it in one byte at a time. */
398 1.9 mycroft for (i=0; i<size; i++)
399 1.9 mycroft tmp = (tmp << 8) | ptr[i];
400 1.9 mycroft
401 1.9 mycroft tmp &= ~mask;
402 1.9 mycroft tmp |= value;
403 1.9 mycroft
404 1.9 mycroft /* Write it back out. */
405 1.9 mycroft for (i=0; i<size; i++)
406 1.9 mycroft ptr[i] = ((tmp >> (8*i)) & 0xff);
407 1.8 mycroft #ifdef RTLD_DEBUG_RELOC
408 1.9 mycroft value = (Elf_Addr)tmp;
409 1.8 mycroft #endif
410 1.8 mycroft
411 1.9 mycroft } else if (RELOC_TARGET_SIZE(type) > 32) {
412 1.9 mycroft *where &= ~mask;
413 1.9 mycroft *where |= value;
414 1.8 mycroft #ifdef RTLD_DEBUG_RELOC
415 1.9 mycroft value = (Elf_Addr)*where;
416 1.8 mycroft #endif
417 1.9 mycroft } else {
418 1.9 mycroft Elf32_Addr *where32 = (Elf32_Addr *)where;
419 1.8 mycroft
420 1.9 mycroft *where32 &= ~mask;
421 1.9 mycroft *where32 |= value;
422 1.8 mycroft #ifdef RTLD_DEBUG_RELOC
423 1.9 mycroft value = (Elf_Addr)*where32;
424 1.8 mycroft #endif
425 1.9 mycroft }
426 1.8 mycroft
427 1.8 mycroft #ifdef RTLD_DEBUG_RELOC
428 1.9 mycroft if (RELOC_RESOLVE_SYMBOL(type)) {
429 1.21 mycroft rdbg(("%s %s in %s --> %p in %s", reloc_names[type],
430 1.11 mycroft obj->strtab + obj->symtab[symnum].st_name,
431 1.33 petrov obj->path, (void *)value, defobj->path));
432 1.11 mycroft } else {
433 1.21 mycroft rdbg(("%s in %s --> %p", reloc_names[type],
434 1.33 petrov obj->path, (void *)value));
435 1.9 mycroft }
436 1.9 mycroft #endif
437 1.8 mycroft }
438 1.13 mycroft return (0);
439 1.13 mycroft }
440 1.13 mycroft
441 1.13 mycroft int
442 1.34 skrll _rtld_relocate_plt_lazy(const Obj_Entry *obj)
443 1.13 mycroft {
444 1.8 mycroft return (0);
445 1.23 mycroft }
446 1.23 mycroft
447 1.23 mycroft caddr_t
448 1.34 skrll _rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
449 1.23 mycroft {
450 1.24 mycroft const Elf_Rela *rela = obj->pltrela + reloff;
451 1.35 martin Elf_Addr result;
452 1.35 martin int err;
453 1.23 mycroft
454 1.39 mrg result = 0; /* XXX gcc */
455 1.39 mrg
456 1.23 mycroft if (ELF_R_TYPE(obj->pltrela->r_info) == R_TYPE(JMP_SLOT)) {
457 1.23 mycroft /*
458 1.23 mycroft * XXXX
459 1.23 mycroft *
460 1.23 mycroft * The first four PLT entries are reserved. There is some
461 1.23 mycroft * disagreement whether they should have associated relocation
462 1.23 mycroft * entries. Both the SPARC 32-bit and 64-bit ELF
463 1.23 mycroft * specifications say that they should have relocation entries,
464 1.23 mycroft * but the 32-bit SPARC binutils do not generate them, and now
465 1.23 mycroft * the 64-bit SPARC binutils have stopped generating them too.
466 1.23 mycroft *
467 1.23 mycroft * So, to provide binary compatibility, we will check the first
468 1.23 mycroft * entry, if it is reserved it should not be of the type
469 1.23 mycroft * JMP_SLOT. If it is JMP_SLOT, then the 4 reserved entries
470 1.23 mycroft * were not generated and our index is 4 entries too far.
471 1.23 mycroft */
472 1.23 mycroft rela -= 4;
473 1.23 mycroft }
474 1.32 thorpej
475 1.35 martin err = _rtld_relocate_plt_object(obj, rela, &result);
476 1.46 christos if (err)
477 1.35 martin _rtld_die();
478 1.35 martin
479 1.35 martin return (caddr_t)result;
480 1.35 martin }
481 1.35 martin
482 1.35 martin int
483 1.35 martin _rtld_relocate_plt_objects(const Obj_Entry *obj)
484 1.35 martin {
485 1.35 martin const Elf_Rela *rela;
486 1.35 martin
487 1.35 martin rela = obj->pltrela;
488 1.35 martin
489 1.35 martin /*
490 1.35 martin * Check for first four reserved entries - and skip them.
491 1.35 martin * See above for details.
492 1.35 martin */
493 1.35 martin if (ELF_R_TYPE(obj->pltrela->r_info) != R_TYPE(JMP_SLOT))
494 1.35 martin rela += 4;
495 1.35 martin
496 1.35 martin for (; rela < obj->pltrelalim; rela++)
497 1.35 martin if (_rtld_relocate_plt_object(obj, rela, NULL) < 0)
498 1.35 martin return -1;
499 1.35 martin
500 1.35 martin return 0;
501 1.35 martin }
502 1.35 martin
503 1.35 martin /*
504 1.35 martin * New inline function that is called by _rtld_relocate_plt_object and
505 1.35 martin * _rtld_bind
506 1.35 martin */
507 1.35 martin static inline int
508 1.35 martin _rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela, Elf_Addr *tp)
509 1.35 martin {
510 1.35 martin Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
511 1.35 martin const Elf_Sym *def;
512 1.35 martin const Obj_Entry *defobj;
513 1.35 martin Elf_Addr value, offset;
514 1.46 christos unsigned long info = rela->r_info;
515 1.23 mycroft
516 1.46 christos assert(ELF_R_TYPE(info) == R_TYPE(JMP_SLOT));
517 1.23 mycroft
518 1.46 christos def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj, tp != NULL);
519 1.46 christos if (__predict_false(def == NULL))
520 1.35 martin return -1;
521 1.46 christos if (__predict_false(def == &_rtld_sym_zero))
522 1.46 christos return 0;
523 1.23 mycroft
524 1.23 mycroft value = (Elf_Addr)(defobj->relocbase + def->st_value);
525 1.27 mycroft rdbg(("bind now/fixup in %s --> new=%p",
526 1.27 mycroft defobj->strtab + def->st_name, (void *)value));
527 1.23 mycroft
528 1.23 mycroft /*
529 1.23 mycroft * At the PLT entry pointed at by `where', we now construct
530 1.23 mycroft * a direct transfer to the now fully resolved function
531 1.23 mycroft * address.
532 1.23 mycroft *
533 1.23 mycroft * A PLT entry is supposed to start by looking like this:
534 1.23 mycroft *
535 1.23 mycroft * sethi %hi(. - .PLT0), %g1
536 1.23 mycroft * ba,a %xcc, .PLT1
537 1.23 mycroft * nop
538 1.23 mycroft * nop
539 1.23 mycroft * nop
540 1.23 mycroft * nop
541 1.23 mycroft * nop
542 1.23 mycroft * nop
543 1.23 mycroft *
544 1.23 mycroft * When we replace these entries we start from the second
545 1.23 mycroft * entry and do it in reverse order so the last thing we
546 1.23 mycroft * do is replace the branch. That allows us to change this
547 1.23 mycroft * atomically.
548 1.23 mycroft *
549 1.23 mycroft * We now need to find out how far we need to jump. We
550 1.23 mycroft * have a choice of several different relocation techniques
551 1.23 mycroft * which are increasingly expensive.
552 1.23 mycroft */
553 1.23 mycroft
554 1.23 mycroft offset = ((Elf_Addr)where) - value;
555 1.23 mycroft if (rela->r_addend) {
556 1.23 mycroft Elf_Addr *ptr = (Elf_Addr *)where;
557 1.23 mycroft /*
558 1.28 mycroft * This entry is >=32768. The relocations points to a
559 1.28 mycroft * PC-relative pointer to the bind_0 stub at the top of the
560 1.28 mycroft * PLT section. Update it to point to the target function.
561 1.23 mycroft */
562 1.27 mycroft ptr[0] += value - (Elf_Addr)obj->pltgot;
563 1.23 mycroft
564 1.45 martin } else if (offset <= (1L<<20) && (Elf_SOff)offset >= -(1L<<20)) {
565 1.23 mycroft /*
566 1.23 mycroft * We're within 1MB -- we can use a direct branch insn.
567 1.23 mycroft *
568 1.23 mycroft * We can generate this pattern:
569 1.23 mycroft *
570 1.23 mycroft * sethi %hi(. - .PLT0), %g1
571 1.23 mycroft * ba,a %xcc, addr
572 1.23 mycroft * nop
573 1.23 mycroft * nop
574 1.23 mycroft * nop
575 1.23 mycroft * nop
576 1.23 mycroft * nop
577 1.23 mycroft * nop
578 1.23 mycroft *
579 1.23 mycroft */
580 1.23 mycroft where[1] = BAA | ((offset >> 2) &0x3fffff);
581 1.38 perry __asm volatile("iflush %0+4" : : "r" (where));
582 1.45 martin } else if (value < (1L<<32)) {
583 1.23 mycroft /*
584 1.26 mycroft * We're within 32-bits of address zero.
585 1.23 mycroft *
586 1.23 mycroft * The resulting code in the jump slot is:
587 1.23 mycroft *
588 1.23 mycroft * sethi %hi(. - .PLT0), %g1
589 1.23 mycroft * sethi %hi(addr), %g1
590 1.23 mycroft * jmp %g1+%lo(addr)
591 1.23 mycroft * nop
592 1.23 mycroft * nop
593 1.23 mycroft * nop
594 1.23 mycroft * nop
595 1.23 mycroft * nop
596 1.23 mycroft *
597 1.23 mycroft */
598 1.26 mycroft where[2] = JMP | LOVAL(value, 0);
599 1.23 mycroft where[1] = SETHI | HIVAL(value, 10);
600 1.38 perry __asm volatile("iflush %0+8" : : "r" (where));
601 1.38 perry __asm volatile("iflush %0+4" : : "r" (where));
602 1.23 mycroft
603 1.45 martin } else if ((Elf_SOff)value <= 0 && (Elf_SOff)value > -(1L<<32)) {
604 1.23 mycroft /*
605 1.26 mycroft * We're within 32-bits of address -1.
606 1.23 mycroft *
607 1.23 mycroft * The resulting code in the jump slot is:
608 1.23 mycroft *
609 1.23 mycroft * sethi %hi(. - .PLT0), %g1
610 1.23 mycroft * sethi %hix(addr), %g1
611 1.23 mycroft * xor %g1, %lox(addr), %g1
612 1.23 mycroft * jmp %g1
613 1.23 mycroft * nop
614 1.23 mycroft * nop
615 1.23 mycroft * nop
616 1.23 mycroft * nop
617 1.23 mycroft *
618 1.23 mycroft */
619 1.23 mycroft where[3] = JMP;
620 1.23 mycroft where[2] = XOR | ((~value) & 0x00001fff);
621 1.23 mycroft where[1] = SETHI | HIVAL(~value, 10);
622 1.38 perry __asm volatile("iflush %0+12" : : "r" (where));
623 1.38 perry __asm volatile("iflush %0+8" : : "r" (where));
624 1.38 perry __asm volatile("iflush %0+4" : : "r" (where));
625 1.23 mycroft
626 1.45 martin } else if (offset <= (1L<<32) && (Elf_SOff)offset >= -((1L<<32) - 4)) {
627 1.23 mycroft /*
628 1.26 mycroft * We're within 32-bits -- we can use a direct call insn
629 1.23 mycroft *
630 1.23 mycroft * The resulting code in the jump slot is:
631 1.23 mycroft *
632 1.23 mycroft * sethi %hi(. - .PLT0), %g1
633 1.23 mycroft * mov %o7, %g1
634 1.23 mycroft * call (.+offset)
635 1.23 mycroft * mov %g1, %o7
636 1.23 mycroft * nop
637 1.23 mycroft * nop
638 1.23 mycroft * nop
639 1.23 mycroft * nop
640 1.23 mycroft *
641 1.23 mycroft */
642 1.23 mycroft where[3] = MOV17;
643 1.23 mycroft where[2] = CALL | ((offset >> 4) & 0x3fffffff);
644 1.23 mycroft where[1] = MOV71;
645 1.38 perry __asm volatile("iflush %0+12" : : "r" (where));
646 1.38 perry __asm volatile("iflush %0+8" : : "r" (where));
647 1.38 perry __asm volatile("iflush %0+4" : : "r" (where));
648 1.23 mycroft
649 1.45 martin } else if (offset < (1L<<44)) {
650 1.23 mycroft /*
651 1.26 mycroft * We're within 44 bits. We can generate this pattern:
652 1.23 mycroft *
653 1.23 mycroft * The resulting code in the jump slot is:
654 1.23 mycroft *
655 1.23 mycroft * sethi %hi(. - .PLT0), %g1
656 1.23 mycroft * sethi %h44(addr), %g1
657 1.23 mycroft * or %g1, %m44(addr), %g1
658 1.23 mycroft * sllx %g1, 12, %g1
659 1.23 mycroft * jmp %g1+%l44(addr)
660 1.23 mycroft * nop
661 1.23 mycroft * nop
662 1.23 mycroft * nop
663 1.23 mycroft *
664 1.23 mycroft */
665 1.26 mycroft where[4] = JMP | LOVAL(offset, 0);
666 1.23 mycroft where[3] = SLLX | 12;
667 1.23 mycroft where[2] = OR | (((offset) >> 12) & 0x00001fff);
668 1.23 mycroft where[1] = SETHI | HIVAL(offset, 22);
669 1.38 perry __asm volatile("iflush %0+16" : : "r" (where));
670 1.38 perry __asm volatile("iflush %0+12" : : "r" (where));
671 1.38 perry __asm volatile("iflush %0+8" : : "r" (where));
672 1.38 perry __asm volatile("iflush %0+4" : : "r" (where));
673 1.23 mycroft
674 1.45 martin } else if ((Elf_SOff)offset < 0 && (Elf_SOff)offset > -(1L<<44)) {
675 1.23 mycroft /*
676 1.26 mycroft * We're within 44 bits. We can generate this pattern:
677 1.23 mycroft *
678 1.23 mycroft * The resulting code in the jump slot is:
679 1.23 mycroft *
680 1.23 mycroft * sethi %hi(. - .PLT0), %g1
681 1.23 mycroft * sethi %h44(-addr), %g1
682 1.23 mycroft * xor %g1, %m44(-addr), %g1
683 1.23 mycroft * sllx %g1, 12, %g1
684 1.23 mycroft * jmp %g1+%l44(addr)
685 1.23 mycroft * nop
686 1.23 mycroft * nop
687 1.23 mycroft * nop
688 1.23 mycroft *
689 1.23 mycroft */
690 1.26 mycroft where[4] = JMP | LOVAL(offset, 0);
691 1.23 mycroft where[3] = SLLX | 12;
692 1.23 mycroft where[2] = XOR | (((~offset) >> 12) & 0x00001fff);
693 1.23 mycroft where[1] = SETHI | HIVAL(~offset, 22);
694 1.38 perry __asm volatile("iflush %0+16" : : "r" (where));
695 1.38 perry __asm volatile("iflush %0+12" : : "r" (where));
696 1.38 perry __asm volatile("iflush %0+8" : : "r" (where));
697 1.38 perry __asm volatile("iflush %0+4" : : "r" (where));
698 1.23 mycroft
699 1.23 mycroft } else {
700 1.23 mycroft /*
701 1.23 mycroft * We need to load all 64-bits
702 1.23 mycroft *
703 1.23 mycroft * The resulting code in the jump slot is:
704 1.23 mycroft *
705 1.23 mycroft * sethi %hi(. - .PLT0), %g1
706 1.23 mycroft * sethi %hh(addr), %g1
707 1.23 mycroft * sethi %lm(addr), %g5
708 1.23 mycroft * or %g1, %hm(addr), %g1
709 1.23 mycroft * sllx %g1, 32, %g1
710 1.23 mycroft * or %g1, %g5, %g1
711 1.23 mycroft * jmp %g1+%lo(addr)
712 1.23 mycroft * nop
713 1.23 mycroft *
714 1.23 mycroft */
715 1.26 mycroft where[6] = JMP | LOVAL(value, 0);
716 1.23 mycroft where[5] = ORG5;
717 1.26 mycroft where[4] = SLLX | 32;
718 1.26 mycroft where[3] = OR | LOVAL(value, 32);
719 1.23 mycroft where[2] = SETHIG5 | HIVAL(value, 10);
720 1.23 mycroft where[1] = SETHI | HIVAL(value, 42);
721 1.38 perry __asm volatile("iflush %0+24" : : "r" (where));
722 1.38 perry __asm volatile("iflush %0+20" : : "r" (where));
723 1.38 perry __asm volatile("iflush %0+16" : : "r" (where));
724 1.38 perry __asm volatile("iflush %0+12" : : "r" (where));
725 1.38 perry __asm volatile("iflush %0+8" : : "r" (where));
726 1.38 perry __asm volatile("iflush %0+4" : : "r" (where));
727 1.23 mycroft
728 1.23 mycroft }
729 1.23 mycroft
730 1.35 martin if (tp)
731 1.35 martin *tp = value;
732 1.35 martin
733 1.35 martin return 0;
734 1.6 mycroft }
735