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4a657b0d DK |
1 | // arm.cc -- arm target support for gold. |
2 | ||
3 | // Copyright 2009 Free Software Foundation, Inc. | |
4 | // Written by Doug Kwan <dougkwan@google.com> based on the i386 code | |
5 | // by Ian Lance Taylor <iant@google.com>. | |
6 | ||
7 | // This file is part of gold. | |
8 | ||
9 | // This program is free software; you can redistribute it and/or modify | |
10 | // it under the terms of the GNU General Public License as published by | |
11 | // the Free Software Foundation; either version 3 of the License, or | |
12 | // (at your option) any later version. | |
13 | ||
14 | // This program is distributed in the hope that it will be useful, | |
15 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | // GNU General Public License for more details. | |
18 | ||
19 | // You should have received a copy of the GNU General Public License | |
20 | // along with this program; if not, write to the Free Software | |
21 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
22 | // MA 02110-1301, USA. | |
23 | ||
24 | #include "gold.h" | |
25 | ||
26 | #include <cstring> | |
27 | #include <limits> | |
28 | #include <cstdio> | |
29 | #include <string> | |
30 | ||
31 | #include "elfcpp.h" | |
32 | #include "parameters.h" | |
33 | #include "reloc.h" | |
34 | #include "arm.h" | |
35 | #include "object.h" | |
36 | #include "symtab.h" | |
37 | #include "layout.h" | |
38 | #include "output.h" | |
39 | #include "copy-relocs.h" | |
40 | #include "target.h" | |
41 | #include "target-reloc.h" | |
42 | #include "target-select.h" | |
43 | #include "tls.h" | |
44 | #include "defstd.h" | |
45 | ||
46 | namespace | |
47 | { | |
48 | ||
49 | using namespace gold; | |
50 | ||
94cdfcff DK |
51 | template<bool big_endian> |
52 | class Output_data_plt_arm; | |
53 | ||
4a657b0d DK |
54 | // The arm target class. |
55 | // | |
56 | // This is a very simple port of gold for ARM-EABI. It is intended for | |
57 | // supporting Android only for the time being. Only these relocation types | |
58 | // are supported. | |
59 | // | |
60 | // R_ARM_NONE | |
61 | // R_ARM_ABS32 | |
62 | // R_ARM_REL32 | |
63 | // R_ARM_THM_CALL | |
64 | // R_ARM_COPY | |
65 | // R_ARM_GLOB_DAT | |
66 | // R_ARM_BASE_PREL | |
67 | // R_ARM_JUMP_SLOT | |
68 | // R_ARM_RELATIVE | |
69 | // R_ARM_GOTOFF32 | |
70 | // R_ARM_GOT_BREL | |
71 | // R_ARM_PLT32 | |
72 | // R_ARM_CALL | |
73 | // R_ARM_JUMP24 | |
74 | // R_ARM_TARGET1 | |
75 | // R_ARM_PREL31 | |
76 | // | |
77 | // Coming soon (pending patches): | |
4a657b0d DK |
78 | // - Defining section symbols __exidx_start and __exidx_stop. |
79 | // - Support interworking. | |
80 | // - Mergeing all .ARM.xxx.yyy sections into .ARM.xxx. Currently, they | |
81 | // are incorrectly merged into an .ARM section. | |
82 | // | |
83 | // TODOs: | |
84 | // - Create a PT_ARM_EXIDX program header for a shared object that | |
85 | // might throw an exception. | |
86 | // - Support more relocation types as needed. | |
94cdfcff DK |
87 | // - Make PLTs more flexible for different architecture features like |
88 | // Thumb-2 and BE8. | |
4a657b0d | 89 | |
c121c671 DK |
90 | // Utilities for manipulating integers of up to 32-bits |
91 | ||
92 | namespace utils | |
93 | { | |
94 | // Sign extend an n-bit unsigned integer stored in an uint32_t into | |
95 | // an int32_t. NO_BITS must be between 1 to 32. | |
96 | template<int no_bits> | |
97 | static inline int32_t | |
98 | sign_extend(uint32_t bits) | |
99 | { | |
96d49306 | 100 | gold_assert(no_bits >= 0 && no_bits <= 32); |
c121c671 DK |
101 | if (no_bits == 32) |
102 | return static_cast<int32_t>(bits); | |
103 | uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits); | |
104 | bits &= mask; | |
105 | uint32_t top_bit = 1U << (no_bits - 1); | |
106 | int32_t as_signed = static_cast<int32_t>(bits); | |
107 | return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed; | |
108 | } | |
109 | ||
110 | // Detects overflow of an NO_BITS integer stored in a uint32_t. | |
111 | template<int no_bits> | |
112 | static inline bool | |
113 | has_overflow(uint32_t bits) | |
114 | { | |
96d49306 | 115 | gold_assert(no_bits >= 0 && no_bits <= 32); |
c121c671 DK |
116 | if (no_bits == 32) |
117 | return false; | |
118 | int32_t max = (1 << (no_bits - 1)) - 1; | |
119 | int32_t min = -(1 << (no_bits - 1)); | |
120 | int32_t as_signed = static_cast<int32_t>(bits); | |
121 | return as_signed > max || as_signed < min; | |
122 | } | |
123 | ||
124 | // Select bits from A and B using bits in MASK. For each n in [0..31], | |
125 | // the n-th bit in the result is chosen from the n-th bits of A and B. | |
126 | // A zero selects A and a one selects B. | |
127 | static inline uint32_t | |
128 | bit_select(uint32_t a, uint32_t b, uint32_t mask) | |
129 | { return (a & ~mask) | (b & mask); } | |
130 | }; | |
131 | ||
4a657b0d DK |
132 | template<bool big_endian> |
133 | class Target_arm : public Sized_target<32, big_endian> | |
134 | { | |
135 | public: | |
136 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian> | |
137 | Reloc_section; | |
138 | ||
139 | Target_arm() | |
94cdfcff DK |
140 | : Sized_target<32, big_endian>(&arm_info), |
141 | got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL), | |
142 | copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL) | |
4a657b0d DK |
143 | { } |
144 | ||
145 | // Process the relocations to determine unreferenced sections for | |
146 | // garbage collection. | |
147 | void | |
148 | gc_process_relocs(const General_options& options, | |
149 | Symbol_table* symtab, | |
150 | Layout* layout, | |
151 | Sized_relobj<32, big_endian>* object, | |
152 | unsigned int data_shndx, | |
153 | unsigned int sh_type, | |
154 | const unsigned char* prelocs, | |
155 | size_t reloc_count, | |
156 | Output_section* output_section, | |
157 | bool needs_special_offset_handling, | |
158 | size_t local_symbol_count, | |
159 | const unsigned char* plocal_symbols); | |
160 | ||
161 | // Scan the relocations to look for symbol adjustments. | |
162 | void | |
163 | scan_relocs(const General_options& options, | |
164 | Symbol_table* symtab, | |
165 | Layout* layout, | |
166 | Sized_relobj<32, big_endian>* object, | |
167 | unsigned int data_shndx, | |
168 | unsigned int sh_type, | |
169 | const unsigned char* prelocs, | |
170 | size_t reloc_count, | |
171 | Output_section* output_section, | |
172 | bool needs_special_offset_handling, | |
173 | size_t local_symbol_count, | |
174 | const unsigned char* plocal_symbols); | |
175 | ||
176 | // Finalize the sections. | |
177 | void | |
178 | do_finalize_sections(Layout*); | |
179 | ||
94cdfcff | 180 | // Return the value to use for a dynamic symbol which requires special |
4a657b0d DK |
181 | // treatment. |
182 | uint64_t | |
183 | do_dynsym_value(const Symbol*) const; | |
184 | ||
185 | // Relocate a section. | |
186 | void | |
187 | relocate_section(const Relocate_info<32, big_endian>*, | |
188 | unsigned int sh_type, | |
189 | const unsigned char* prelocs, | |
190 | size_t reloc_count, | |
191 | Output_section* output_section, | |
192 | bool needs_special_offset_handling, | |
193 | unsigned char* view, | |
194 | elfcpp::Elf_types<32>::Elf_Addr view_address, | |
195 | section_size_type view_size); | |
196 | ||
197 | // Scan the relocs during a relocatable link. | |
198 | void | |
199 | scan_relocatable_relocs(const General_options& options, | |
200 | Symbol_table* symtab, | |
201 | Layout* layout, | |
202 | Sized_relobj<32, big_endian>* object, | |
203 | unsigned int data_shndx, | |
204 | unsigned int sh_type, | |
205 | const unsigned char* prelocs, | |
206 | size_t reloc_count, | |
207 | Output_section* output_section, | |
208 | bool needs_special_offset_handling, | |
209 | size_t local_symbol_count, | |
210 | const unsigned char* plocal_symbols, | |
211 | Relocatable_relocs*); | |
212 | ||
213 | // Relocate a section during a relocatable link. | |
214 | void | |
215 | relocate_for_relocatable(const Relocate_info<32, big_endian>*, | |
216 | unsigned int sh_type, | |
217 | const unsigned char* prelocs, | |
218 | size_t reloc_count, | |
219 | Output_section* output_section, | |
220 | off_t offset_in_output_section, | |
221 | const Relocatable_relocs*, | |
222 | unsigned char* view, | |
223 | elfcpp::Elf_types<32>::Elf_Addr view_address, | |
224 | section_size_type view_size, | |
225 | unsigned char* reloc_view, | |
226 | section_size_type reloc_view_size); | |
227 | ||
228 | // Return whether SYM is defined by the ABI. | |
229 | bool | |
230 | do_is_defined_by_abi(Symbol* sym) const | |
231 | { return strcmp(sym->name(), "__tls_get_addr") == 0; } | |
232 | ||
94cdfcff DK |
233 | // Return the size of the GOT section. |
234 | section_size_type | |
235 | got_size() | |
236 | { | |
237 | gold_assert(this->got_ != NULL); | |
238 | return this->got_->data_size(); | |
239 | } | |
240 | ||
4a657b0d DK |
241 | // Map platform-specific reloc types |
242 | static unsigned int | |
243 | get_real_reloc_type (unsigned int r_type); | |
244 | ||
245 | private: | |
246 | // The class which scans relocations. | |
247 | class Scan | |
248 | { | |
249 | public: | |
250 | Scan() | |
bec53400 | 251 | : issued_non_pic_error_(false) |
4a657b0d DK |
252 | { } |
253 | ||
254 | inline void | |
255 | local(const General_options& options, Symbol_table* symtab, | |
256 | Layout* layout, Target_arm* target, | |
257 | Sized_relobj<32, big_endian>* object, | |
258 | unsigned int data_shndx, | |
259 | Output_section* output_section, | |
260 | const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, | |
261 | const elfcpp::Sym<32, big_endian>& lsym); | |
262 | ||
263 | inline void | |
264 | global(const General_options& options, Symbol_table* symtab, | |
265 | Layout* layout, Target_arm* target, | |
266 | Sized_relobj<32, big_endian>* object, | |
267 | unsigned int data_shndx, | |
268 | Output_section* output_section, | |
269 | const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, | |
270 | Symbol* gsym); | |
271 | ||
272 | private: | |
273 | static void | |
274 | unsupported_reloc_local(Sized_relobj<32, big_endian>*, | |
275 | unsigned int r_type); | |
276 | ||
277 | static void | |
278 | unsupported_reloc_global(Sized_relobj<32, big_endian>*, | |
279 | unsigned int r_type, Symbol*); | |
bec53400 DK |
280 | |
281 | void | |
282 | check_non_pic(Relobj*, unsigned int r_type); | |
283 | ||
284 | // Almost identical to Symbol::needs_plt_entry except that it also | |
285 | // handles STT_ARM_TFUNC. | |
286 | static bool | |
287 | symbol_needs_plt_entry(const Symbol* sym) | |
288 | { | |
289 | // An undefined symbol from an executable does not need a PLT entry. | |
290 | if (sym->is_undefined() && !parameters->options().shared()) | |
291 | return false; | |
292 | ||
293 | return (!parameters->doing_static_link() | |
294 | && (sym->type() == elfcpp::STT_FUNC | |
295 | || sym->type() == elfcpp::STT_ARM_TFUNC) | |
296 | && (sym->is_from_dynobj() | |
297 | || sym->is_undefined() | |
298 | || sym->is_preemptible())); | |
299 | } | |
300 | ||
301 | // Whether we have issued an error about a non-PIC compilation. | |
302 | bool issued_non_pic_error_; | |
4a657b0d DK |
303 | }; |
304 | ||
305 | // The class which implements relocation. | |
306 | class Relocate | |
307 | { | |
308 | public: | |
309 | Relocate() | |
310 | { } | |
311 | ||
312 | ~Relocate() | |
313 | { } | |
314 | ||
bec53400 DK |
315 | // Return whether the static relocation needs to be applied. |
316 | inline bool | |
317 | should_apply_static_reloc(const Sized_symbol<32>* gsym, | |
318 | int ref_flags, | |
319 | bool is_32bit, | |
320 | Output_section* output_section); | |
321 | ||
4a657b0d DK |
322 | // Do a relocation. Return false if the caller should not issue |
323 | // any warnings about this relocation. | |
324 | inline bool | |
325 | relocate(const Relocate_info<32, big_endian>*, Target_arm*, | |
326 | Output_section*, size_t relnum, | |
327 | const elfcpp::Rel<32, big_endian>&, | |
328 | unsigned int r_type, const Sized_symbol<32>*, | |
329 | const Symbol_value<32>*, | |
330 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, | |
331 | section_size_type); | |
c121c671 DK |
332 | |
333 | // Return whether we want to pass flag NON_PIC_REF for this | |
334 | // reloc. | |
335 | static inline bool | |
336 | reloc_is_non_pic (unsigned int r_type) | |
337 | { | |
338 | switch (r_type) | |
339 | { | |
340 | case elfcpp::R_ARM_REL32: | |
341 | case elfcpp::R_ARM_THM_CALL: | |
342 | case elfcpp::R_ARM_CALL: | |
343 | case elfcpp::R_ARM_JUMP24: | |
344 | case elfcpp::R_ARM_PREL31: | |
345 | return true; | |
346 | default: | |
347 | return false; | |
348 | } | |
349 | } | |
4a657b0d DK |
350 | }; |
351 | ||
352 | // A class which returns the size required for a relocation type, | |
353 | // used while scanning relocs during a relocatable link. | |
354 | class Relocatable_size_for_reloc | |
355 | { | |
356 | public: | |
357 | unsigned int | |
358 | get_size_for_reloc(unsigned int, Relobj*); | |
359 | }; | |
360 | ||
94cdfcff DK |
361 | // Get the GOT section, creating it if necessary. |
362 | Output_data_got<32, big_endian>* | |
363 | got_section(Symbol_table*, Layout*); | |
364 | ||
365 | // Get the GOT PLT section. | |
366 | Output_data_space* | |
367 | got_plt_section() const | |
368 | { | |
369 | gold_assert(this->got_plt_ != NULL); | |
370 | return this->got_plt_; | |
371 | } | |
372 | ||
373 | // Create a PLT entry for a global symbol. | |
374 | void | |
375 | make_plt_entry(Symbol_table*, Layout*, Symbol*); | |
376 | ||
377 | // Get the PLT section. | |
378 | const Output_data_plt_arm<big_endian>* | |
379 | plt_section() const | |
380 | { | |
381 | gold_assert(this->plt_ != NULL); | |
382 | return this->plt_; | |
383 | } | |
384 | ||
385 | // Get the dynamic reloc section, creating it if necessary. | |
386 | Reloc_section* | |
387 | rel_dyn_section(Layout*); | |
388 | ||
389 | // Return true if the symbol may need a COPY relocation. | |
390 | // References from an executable object to non-function symbols | |
391 | // defined in a dynamic object may need a COPY relocation. | |
392 | bool | |
393 | may_need_copy_reloc(Symbol* gsym) | |
394 | { | |
395 | return (!parameters->options().shared() | |
396 | && gsym->is_from_dynobj() | |
bec53400 DK |
397 | && gsym->type() != elfcpp::STT_FUNC |
398 | && gsym->type() != elfcpp::STT_ARM_TFUNC); | |
94cdfcff DK |
399 | } |
400 | ||
401 | // Add a potential copy relocation. | |
402 | void | |
403 | copy_reloc(Symbol_table* symtab, Layout* layout, | |
404 | Sized_relobj<32, big_endian>* object, | |
405 | unsigned int shndx, Output_section* output_section, | |
406 | Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc) | |
407 | { | |
408 | this->copy_relocs_.copy_reloc(symtab, layout, | |
409 | symtab->get_sized_symbol<32>(sym), | |
410 | object, shndx, output_section, reloc, | |
411 | this->rel_dyn_section(layout)); | |
412 | } | |
413 | ||
4a657b0d DK |
414 | // Information about this specific target which we pass to the |
415 | // general Target structure. | |
416 | static const Target::Target_info arm_info; | |
94cdfcff DK |
417 | |
418 | // The types of GOT entries needed for this platform. | |
419 | enum Got_type | |
420 | { | |
421 | GOT_TYPE_STANDARD = 0 // GOT entry for a regular symbol | |
422 | }; | |
423 | ||
424 | // The GOT section. | |
425 | Output_data_got<32, big_endian>* got_; | |
426 | // The PLT section. | |
427 | Output_data_plt_arm<big_endian>* plt_; | |
428 | // The GOT PLT section. | |
429 | Output_data_space* got_plt_; | |
430 | // The dynamic reloc section. | |
431 | Reloc_section* rel_dyn_; | |
432 | // Relocs saved to avoid a COPY reloc. | |
433 | Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_; | |
434 | // Space for variables copied with a COPY reloc. | |
435 | Output_data_space* dynbss_; | |
4a657b0d DK |
436 | }; |
437 | ||
438 | template<bool big_endian> | |
439 | const Target::Target_info Target_arm<big_endian>::arm_info = | |
440 | { | |
441 | 32, // size | |
442 | big_endian, // is_big_endian | |
443 | elfcpp::EM_ARM, // machine_code | |
444 | false, // has_make_symbol | |
445 | false, // has_resolve | |
446 | false, // has_code_fill | |
447 | true, // is_default_stack_executable | |
448 | '\0', // wrap_char | |
449 | "/usr/lib/libc.so.1", // dynamic_linker | |
450 | 0x8000, // default_text_segment_address | |
451 | 0x1000, // abi_pagesize (overridable by -z max-page-size) | |
8a5e3e08 ILT |
452 | 0x1000, // common_pagesize (overridable by -z common-page-size) |
453 | elfcpp::SHN_UNDEF, // small_common_shndx | |
454 | elfcpp::SHN_UNDEF, // large_common_shndx | |
455 | 0, // small_common_section_flags | |
456 | 0 // large_common_section_flags | |
4a657b0d DK |
457 | }; |
458 | ||
c121c671 DK |
459 | // Arm relocate functions class |
460 | // | |
461 | ||
462 | template<bool big_endian> | |
463 | class Arm_relocate_functions : public Relocate_functions<32, big_endian> | |
464 | { | |
465 | public: | |
466 | typedef enum | |
467 | { | |
468 | STATUS_OKAY, // No error during relocation. | |
469 | STATUS_OVERFLOW, // Relocation oveflow. | |
470 | STATUS_BAD_RELOC // Relocation cannot be applied. | |
471 | } Status; | |
472 | ||
473 | private: | |
474 | typedef Relocate_functions<32, big_endian> Base; | |
475 | typedef Arm_relocate_functions<big_endian> This; | |
476 | ||
477 | // Get an symbol value of *PSYMVAL with an ADDEND. This is a wrapper | |
478 | // to Symbol_value::value(). If HAS_THUMB_BIT is true, that LSB is used | |
479 | // to distinguish ARM and THUMB functions and it is treated specially. | |
480 | static inline Symbol_value<32>::Value | |
481 | arm_symbol_value (const Sized_relobj<32, big_endian> *object, | |
482 | const Symbol_value<32>* psymval, | |
483 | Symbol_value<32>::Value addend, | |
484 | bool has_thumb_bit) | |
485 | { | |
486 | typedef Symbol_value<32>::Value Valtype; | |
487 | ||
488 | if (has_thumb_bit) | |
489 | { | |
490 | Valtype raw = psymval->value(object, 0); | |
491 | Valtype thumb_bit = raw & 1; | |
492 | return ((raw & ~((Valtype) 1)) + addend) | thumb_bit; | |
493 | } | |
494 | else | |
495 | return psymval->value(object, addend); | |
496 | } | |
497 | ||
498 | // FIXME: This probably only works for Android on ARM v5te. We should | |
499 | // following GNU ld for the general case. | |
500 | template<unsigned r_type> | |
501 | static inline typename This::Status | |
502 | arm_branch_common(unsigned char *view, | |
503 | const Sized_relobj<32, big_endian>* object, | |
504 | const Symbol_value<32>* psymval, | |
505 | elfcpp::Elf_types<32>::Elf_Addr address, | |
506 | bool has_thumb_bit) | |
507 | { | |
508 | typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; | |
509 | Valtype* wv = reinterpret_cast<Valtype*>(view); | |
510 | Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); | |
511 | ||
512 | bool insn_is_b = (((val >> 28) & 0xf) <= 0xe) | |
513 | && ((val & 0x0f000000UL) == 0x0a000000UL); | |
514 | bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL; | |
515 | bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe) | |
516 | && ((val & 0x0f000000UL) == 0x0b000000UL); | |
517 | bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL; | |
518 | bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL; | |
519 | ||
520 | if (r_type == elfcpp::R_ARM_CALL) | |
521 | { | |
522 | if (!insn_is_uncond_bl && !insn_is_blx) | |
523 | return This::STATUS_BAD_RELOC; | |
524 | } | |
525 | else if (r_type == elfcpp::R_ARM_JUMP24) | |
526 | { | |
527 | if (!insn_is_b && !insn_is_cond_bl) | |
528 | return This::STATUS_BAD_RELOC; | |
529 | } | |
530 | else if (r_type == elfcpp::R_ARM_PLT32) | |
531 | { | |
532 | if (!insn_is_any_branch) | |
533 | return This::STATUS_BAD_RELOC; | |
534 | } | |
535 | else | |
536 | gold_unreachable(); | |
537 | ||
538 | Valtype addend = utils::sign_extend<26>(val << 2); | |
539 | Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) | |
540 | - address); | |
541 | ||
542 | // If target has thumb bit set, we need to either turn the BL | |
543 | // into a BLX (for ARMv5 or above) or generate a stub. | |
544 | if (x & 1) | |
545 | { | |
546 | // Turn BL to BLX. | |
547 | if (insn_is_uncond_bl) | |
548 | val = (val & 0xffffff) | 0xfa000000 | ((x & 2) << 23); | |
549 | else | |
550 | return This::STATUS_BAD_RELOC; | |
551 | } | |
552 | else | |
553 | gold_assert(!insn_is_blx); | |
554 | ||
555 | val = utils::bit_select(val, (x >> 2), 0xffffffUL); | |
556 | elfcpp::Swap<32, big_endian>::writeval(wv, val); | |
557 | return (utils::has_overflow<26>(x) | |
558 | ? This::STATUS_OVERFLOW : This::STATUS_OKAY); | |
559 | } | |
560 | ||
561 | public: | |
562 | // R_ARM_ABS32: (S + A) | T | |
563 | static inline typename This::Status | |
564 | abs32(unsigned char *view, | |
565 | const Sized_relobj<32, big_endian>* object, | |
566 | const Symbol_value<32>* psymval, | |
567 | bool has_thumb_bit) | |
568 | { | |
569 | typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; | |
570 | Valtype* wv = reinterpret_cast<Valtype*>(view); | |
571 | Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv); | |
572 | Valtype x = This::arm_symbol_value(object, psymval, addend, has_thumb_bit); | |
573 | elfcpp::Swap<32, big_endian>::writeval(wv, x); | |
574 | return This::STATUS_OKAY; | |
575 | } | |
576 | ||
577 | // R_ARM_REL32: (S + A) | T - P | |
578 | static inline typename This::Status | |
579 | rel32(unsigned char *view, | |
580 | const Sized_relobj<32, big_endian>* object, | |
581 | const Symbol_value<32>* psymval, | |
582 | elfcpp::Elf_types<32>::Elf_Addr address, | |
583 | bool has_thumb_bit) | |
584 | { | |
585 | typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; | |
586 | Valtype* wv = reinterpret_cast<Valtype*>(view); | |
587 | Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv); | |
588 | Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) | |
589 | - address); | |
590 | elfcpp::Swap<32, big_endian>::writeval(wv, x); | |
591 | return This::STATUS_OKAY; | |
592 | } | |
593 | ||
594 | // R_ARM_THM_CALL: (S + A) | T - P | |
595 | static inline typename This::Status | |
596 | thm_call(unsigned char *view, | |
597 | const Sized_relobj<32, big_endian>* object, | |
598 | const Symbol_value<32>* psymval, | |
599 | elfcpp::Elf_types<32>::Elf_Addr address, | |
600 | bool has_thumb_bit) | |
601 | { | |
602 | // A thumb call consists of two instructions. | |
603 | typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; | |
604 | typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; | |
605 | Valtype* wv = reinterpret_cast<Valtype*>(view); | |
606 | Valtype hi = elfcpp::Swap<16, big_endian>::readval(wv); | |
607 | Valtype lo = elfcpp::Swap<16, big_endian>::readval(wv + 1); | |
608 | // Must be a BL instruction. lo == 11111xxxxxxxxxxx. | |
609 | gold_assert((lo & 0xf800) == 0xf800); | |
610 | Reltype addend = utils::sign_extend<23>(((hi & 0x7ff) << 12) | |
611 | | ((lo & 0x7ff) << 1)); | |
612 | Reltype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) | |
613 | - address); | |
614 | ||
615 | // If target has no thumb bit set, we need to either turn the BL | |
616 | // into a BLX (for ARMv5 or above) or generate a stub. | |
617 | if ((x & 1) == 0) | |
618 | { | |
619 | // This only works for ARMv5 and above with interworking enabled. | |
620 | lo &= 0xefff; | |
621 | } | |
622 | hi = utils::bit_select(hi, (x >> 12), 0x7ffU); | |
623 | lo = utils::bit_select(lo, (x >> 1), 0x7ffU); | |
624 | elfcpp::Swap<16, big_endian>::writeval(wv, hi); | |
625 | elfcpp::Swap<16, big_endian>::writeval(wv + 1, lo); | |
626 | return (utils::has_overflow<23>(x) | |
627 | ? This::STATUS_OVERFLOW | |
628 | : This::STATUS_OKAY); | |
629 | } | |
630 | ||
631 | // R_ARM_BASE_PREL: B(S) + A - P | |
632 | static inline typename This::Status | |
633 | base_prel(unsigned char* view, | |
634 | elfcpp::Elf_types<32>::Elf_Addr origin, | |
635 | elfcpp::Elf_types<32>::Elf_Addr address) | |
636 | { | |
637 | Base::rel32(view, origin - address); | |
638 | return STATUS_OKAY; | |
639 | } | |
640 | ||
641 | // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG | |
642 | static inline typename This::Status | |
643 | got_brel(unsigned char* view, | |
644 | typename elfcpp::Swap<32, big_endian>::Valtype got_offset) | |
645 | { | |
646 | Base::rel32(view, got_offset); | |
647 | return This::STATUS_OKAY; | |
648 | } | |
649 | ||
650 | // R_ARM_PLT32: (S + A) | T - P | |
651 | static inline typename This::Status | |
652 | plt32(unsigned char *view, | |
653 | const Sized_relobj<32, big_endian>* object, | |
654 | const Symbol_value<32>* psymval, | |
655 | elfcpp::Elf_types<32>::Elf_Addr address, | |
656 | bool has_thumb_bit) | |
657 | { | |
658 | return arm_branch_common<elfcpp::R_ARM_PLT32>(view, object, psymval, | |
659 | address, has_thumb_bit); | |
660 | } | |
661 | ||
662 | // R_ARM_CALL: (S + A) | T - P | |
663 | static inline typename This::Status | |
664 | call(unsigned char *view, | |
665 | const Sized_relobj<32, big_endian>* object, | |
666 | const Symbol_value<32>* psymval, | |
667 | elfcpp::Elf_types<32>::Elf_Addr address, | |
668 | bool has_thumb_bit) | |
669 | { | |
670 | return arm_branch_common<elfcpp::R_ARM_CALL>(view, object, psymval, | |
671 | address, has_thumb_bit); | |
672 | } | |
673 | ||
674 | // R_ARM_JUMP24: (S + A) | T - P | |
675 | static inline typename This::Status | |
676 | jump24(unsigned char *view, | |
677 | const Sized_relobj<32, big_endian>* object, | |
678 | const Symbol_value<32>* psymval, | |
679 | elfcpp::Elf_types<32>::Elf_Addr address, | |
680 | bool has_thumb_bit) | |
681 | { | |
682 | return arm_branch_common<elfcpp::R_ARM_JUMP24>(view, object, psymval, | |
683 | address, has_thumb_bit); | |
684 | } | |
685 | ||
686 | // R_ARM_PREL: (S + A) | T - P | |
687 | static inline typename This::Status | |
688 | prel31(unsigned char *view, | |
689 | const Sized_relobj<32, big_endian>* object, | |
690 | const Symbol_value<32>* psymval, | |
691 | elfcpp::Elf_types<32>::Elf_Addr address, | |
692 | bool has_thumb_bit) | |
693 | { | |
694 | typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; | |
695 | Valtype* wv = reinterpret_cast<Valtype*>(view); | |
696 | Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); | |
697 | Valtype addend = utils::sign_extend<31>(val); | |
698 | Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) | |
699 | - address); | |
700 | val = utils::bit_select(val, x, 0x7fffffffU); | |
701 | elfcpp::Swap<32, big_endian>::writeval(wv, val); | |
702 | return (utils::has_overflow<31>(x) ? | |
703 | This::STATUS_OVERFLOW : This::STATUS_OKAY); | |
704 | } | |
705 | }; | |
706 | ||
94cdfcff DK |
707 | // Get the GOT section, creating it if necessary. |
708 | ||
709 | template<bool big_endian> | |
710 | Output_data_got<32, big_endian>* | |
711 | Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout) | |
712 | { | |
713 | if (this->got_ == NULL) | |
714 | { | |
715 | gold_assert(symtab != NULL && layout != NULL); | |
716 | ||
717 | this->got_ = new Output_data_got<32, big_endian>(); | |
718 | ||
719 | Output_section* os; | |
720 | os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, | |
721 | (elfcpp::SHF_ALLOC | |
722 | | elfcpp::SHF_WRITE), | |
723 | this->got_); | |
724 | os->set_is_relro(); | |
725 | ||
726 | // The old GNU linker creates a .got.plt section. We just | |
727 | // create another set of data in the .got section. Note that we | |
728 | // always create a PLT if we create a GOT, although the PLT | |
729 | // might be empty. | |
730 | this->got_plt_ = new Output_data_space(4, "** GOT PLT"); | |
731 | os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, | |
732 | (elfcpp::SHF_ALLOC | |
733 | | elfcpp::SHF_WRITE), | |
734 | this->got_plt_); | |
735 | os->set_is_relro(); | |
736 | ||
737 | // The first three entries are reserved. | |
738 | this->got_plt_->set_current_data_size(3 * 4); | |
739 | ||
740 | // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. | |
741 | symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, | |
742 | this->got_plt_, | |
743 | 0, 0, elfcpp::STT_OBJECT, | |
744 | elfcpp::STB_LOCAL, | |
745 | elfcpp::STV_HIDDEN, 0, | |
746 | false, false); | |
747 | } | |
748 | return this->got_; | |
749 | } | |
750 | ||
751 | // Get the dynamic reloc section, creating it if necessary. | |
752 | ||
753 | template<bool big_endian> | |
754 | typename Target_arm<big_endian>::Reloc_section* | |
755 | Target_arm<big_endian>::rel_dyn_section(Layout* layout) | |
756 | { | |
757 | if (this->rel_dyn_ == NULL) | |
758 | { | |
759 | gold_assert(layout != NULL); | |
760 | this->rel_dyn_ = new Reloc_section(parameters->options().combreloc()); | |
761 | layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, | |
762 | elfcpp::SHF_ALLOC, this->rel_dyn_); | |
763 | } | |
764 | return this->rel_dyn_; | |
765 | } | |
766 | ||
767 | // A class to handle the PLT data. | |
768 | ||
769 | template<bool big_endian> | |
770 | class Output_data_plt_arm : public Output_section_data | |
771 | { | |
772 | public: | |
773 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian> | |
774 | Reloc_section; | |
775 | ||
776 | Output_data_plt_arm(Layout*, Output_data_space*); | |
777 | ||
778 | // Add an entry to the PLT. | |
779 | void | |
780 | add_entry(Symbol* gsym); | |
781 | ||
782 | // Return the .rel.plt section data. | |
783 | const Reloc_section* | |
784 | rel_plt() const | |
785 | { return this->rel_; } | |
786 | ||
787 | protected: | |
788 | void | |
789 | do_adjust_output_section(Output_section* os); | |
790 | ||
791 | // Write to a map file. | |
792 | void | |
793 | do_print_to_mapfile(Mapfile* mapfile) const | |
794 | { mapfile->print_output_data(this, _("** PLT")); } | |
795 | ||
796 | private: | |
797 | // Template for the first PLT entry. | |
798 | static const uint32_t first_plt_entry[5]; | |
799 | ||
800 | // Template for subsequent PLT entries. | |
801 | static const uint32_t plt_entry[3]; | |
802 | ||
803 | // Set the final size. | |
804 | void | |
805 | set_final_data_size() | |
806 | { | |
807 | this->set_data_size(sizeof(first_plt_entry) | |
808 | + this->count_ * sizeof(plt_entry)); | |
809 | } | |
810 | ||
811 | // Write out the PLT data. | |
812 | void | |
813 | do_write(Output_file*); | |
814 | ||
815 | // The reloc section. | |
816 | Reloc_section* rel_; | |
817 | // The .got.plt section. | |
818 | Output_data_space* got_plt_; | |
819 | // The number of PLT entries. | |
820 | unsigned int count_; | |
821 | }; | |
822 | ||
823 | // Create the PLT section. The ordinary .got section is an argument, | |
824 | // since we need to refer to the start. We also create our own .got | |
825 | // section just for PLT entries. | |
826 | ||
827 | template<bool big_endian> | |
828 | Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout, | |
829 | Output_data_space* got_plt) | |
830 | : Output_section_data(4), got_plt_(got_plt), count_(0) | |
831 | { | |
832 | this->rel_ = new Reloc_section(false); | |
833 | layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, | |
834 | elfcpp::SHF_ALLOC, this->rel_); | |
835 | } | |
836 | ||
837 | template<bool big_endian> | |
838 | void | |
839 | Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os) | |
840 | { | |
841 | os->set_entsize(0); | |
842 | } | |
843 | ||
844 | // Add an entry to the PLT. | |
845 | ||
846 | template<bool big_endian> | |
847 | void | |
848 | Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym) | |
849 | { | |
850 | gold_assert(!gsym->has_plt_offset()); | |
851 | ||
852 | // Note that when setting the PLT offset we skip the initial | |
853 | // reserved PLT entry. | |
854 | gsym->set_plt_offset((this->count_) * sizeof(plt_entry) | |
855 | + sizeof(first_plt_entry)); | |
856 | ||
857 | ++this->count_; | |
858 | ||
859 | section_offset_type got_offset = this->got_plt_->current_data_size(); | |
860 | ||
861 | // Every PLT entry needs a GOT entry which points back to the PLT | |
862 | // entry (this will be changed by the dynamic linker, normally | |
863 | // lazily when the function is called). | |
864 | this->got_plt_->set_current_data_size(got_offset + 4); | |
865 | ||
866 | // Every PLT entry needs a reloc. | |
867 | gsym->set_needs_dynsym_entry(); | |
868 | this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_, | |
869 | got_offset); | |
870 | ||
871 | // Note that we don't need to save the symbol. The contents of the | |
872 | // PLT are independent of which symbols are used. The symbols only | |
873 | // appear in the relocations. | |
874 | } | |
875 | ||
876 | // ARM PLTs. | |
877 | // FIXME: This is not very flexible. Right now this has only been tested | |
878 | // on armv5te. If we are to support additional architecture features like | |
879 | // Thumb-2 or BE8, we need to make this more flexible like GNU ld. | |
880 | ||
881 | // The first entry in the PLT. | |
882 | template<bool big_endian> | |
883 | const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] = | |
884 | { | |
885 | 0xe52de004, // str lr, [sp, #-4]! | |
886 | 0xe59fe004, // ldr lr, [pc, #4] | |
887 | 0xe08fe00e, // add lr, pc, lr | |
888 | 0xe5bef008, // ldr pc, [lr, #8]! | |
889 | 0x00000000, // &GOT[0] - . | |
890 | }; | |
891 | ||
892 | // Subsequent entries in the PLT. | |
893 | ||
894 | template<bool big_endian> | |
895 | const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] = | |
896 | { | |
897 | 0xe28fc600, // add ip, pc, #0xNN00000 | |
898 | 0xe28cca00, // add ip, ip, #0xNN000 | |
899 | 0xe5bcf000, // ldr pc, [ip, #0xNNN]! | |
900 | }; | |
901 | ||
902 | // Write out the PLT. This uses the hand-coded instructions above, | |
903 | // and adjusts them as needed. This is all specified by the arm ELF | |
904 | // Processor Supplement. | |
905 | ||
906 | template<bool big_endian> | |
907 | void | |
908 | Output_data_plt_arm<big_endian>::do_write(Output_file* of) | |
909 | { | |
910 | const off_t offset = this->offset(); | |
911 | const section_size_type oview_size = | |
912 | convert_to_section_size_type(this->data_size()); | |
913 | unsigned char* const oview = of->get_output_view(offset, oview_size); | |
914 | ||
915 | const off_t got_file_offset = this->got_plt_->offset(); | |
916 | const section_size_type got_size = | |
917 | convert_to_section_size_type(this->got_plt_->data_size()); | |
918 | unsigned char* const got_view = of->get_output_view(got_file_offset, | |
919 | got_size); | |
920 | unsigned char* pov = oview; | |
921 | ||
922 | elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); | |
923 | elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); | |
924 | ||
925 | // Write first PLT entry. All but the last word are constants. | |
926 | const size_t num_first_plt_words = (sizeof(first_plt_entry) | |
927 | / sizeof(plt_entry[0])); | |
928 | for (size_t i = 0; i < num_first_plt_words - 1; i++) | |
929 | elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]); | |
930 | // Last word in first PLT entry is &GOT[0] - . | |
931 | elfcpp::Swap<32, big_endian>::writeval(pov + 16, | |
932 | got_address - (plt_address + 16)); | |
933 | pov += sizeof(first_plt_entry); | |
934 | ||
935 | unsigned char* got_pov = got_view; | |
936 | ||
937 | memset(got_pov, 0, 12); | |
938 | got_pov += 12; | |
939 | ||
940 | const int rel_size = elfcpp::Elf_sizes<32>::rel_size; | |
941 | unsigned int plt_offset = sizeof(first_plt_entry); | |
942 | unsigned int plt_rel_offset = 0; | |
943 | unsigned int got_offset = 12; | |
944 | const unsigned int count = this->count_; | |
945 | for (unsigned int i = 0; | |
946 | i < count; | |
947 | ++i, | |
948 | pov += sizeof(plt_entry), | |
949 | got_pov += 4, | |
950 | plt_offset += sizeof(plt_entry), | |
951 | plt_rel_offset += rel_size, | |
952 | got_offset += 4) | |
953 | { | |
954 | // Set and adjust the PLT entry itself. | |
955 | int32_t offset = ((got_address + got_offset) | |
956 | - (plt_address + plt_offset + 8)); | |
957 | ||
958 | gold_assert(offset >= 0 && offset < 0x0fffffff); | |
959 | uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff); | |
960 | elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0); | |
961 | uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff); | |
962 | elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1); | |
963 | uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff); | |
964 | elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2); | |
965 | ||
966 | // Set the entry in the GOT. | |
967 | elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address); | |
968 | } | |
969 | ||
970 | gold_assert(static_cast<section_size_type>(pov - oview) == oview_size); | |
971 | gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size); | |
972 | ||
973 | of->write_output_view(offset, oview_size, oview); | |
974 | of->write_output_view(got_file_offset, got_size, got_view); | |
975 | } | |
976 | ||
977 | // Create a PLT entry for a global symbol. | |
978 | ||
979 | template<bool big_endian> | |
980 | void | |
981 | Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout, | |
982 | Symbol* gsym) | |
983 | { | |
984 | if (gsym->has_plt_offset()) | |
985 | return; | |
986 | ||
987 | if (this->plt_ == NULL) | |
988 | { | |
989 | // Create the GOT sections first. | |
990 | this->got_section(symtab, layout); | |
991 | ||
992 | this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_); | |
993 | layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, | |
994 | (elfcpp::SHF_ALLOC | |
995 | | elfcpp::SHF_EXECINSTR), | |
996 | this->plt_); | |
997 | } | |
998 | this->plt_->add_entry(gsym); | |
999 | } | |
1000 | ||
4a657b0d DK |
1001 | // Report an unsupported relocation against a local symbol. |
1002 | ||
1003 | template<bool big_endian> | |
1004 | void | |
1005 | Target_arm<big_endian>::Scan::unsupported_reloc_local( | |
1006 | Sized_relobj<32, big_endian>* object, | |
1007 | unsigned int r_type) | |
1008 | { | |
1009 | gold_error(_("%s: unsupported reloc %u against local symbol"), | |
1010 | object->name().c_str(), r_type); | |
1011 | } | |
1012 | ||
bec53400 DK |
1013 | // We are about to emit a dynamic relocation of type R_TYPE. If the |
1014 | // dynamic linker does not support it, issue an error. The GNU linker | |
1015 | // only issues a non-PIC error for an allocated read-only section. | |
1016 | // Here we know the section is allocated, but we don't know that it is | |
1017 | // read-only. But we check for all the relocation types which the | |
1018 | // glibc dynamic linker supports, so it seems appropriate to issue an | |
1019 | // error even if the section is not read-only. | |
1020 | ||
1021 | template<bool big_endian> | |
1022 | void | |
1023 | Target_arm<big_endian>::Scan::check_non_pic(Relobj* object, | |
1024 | unsigned int r_type) | |
1025 | { | |
1026 | switch (r_type) | |
1027 | { | |
1028 | // These are the relocation types supported by glibc for ARM. | |
1029 | case elfcpp::R_ARM_RELATIVE: | |
1030 | case elfcpp::R_ARM_COPY: | |
1031 | case elfcpp::R_ARM_GLOB_DAT: | |
1032 | case elfcpp::R_ARM_JUMP_SLOT: | |
1033 | case elfcpp::R_ARM_ABS32: | |
1034 | case elfcpp::R_ARM_PC24: | |
1035 | // FIXME: The following 3 types are not supported by Android's dynamic | |
1036 | // linker. | |
1037 | case elfcpp::R_ARM_TLS_DTPMOD32: | |
1038 | case elfcpp::R_ARM_TLS_DTPOFF32: | |
1039 | case elfcpp::R_ARM_TLS_TPOFF32: | |
1040 | return; | |
1041 | ||
1042 | default: | |
1043 | // This prevents us from issuing more than one error per reloc | |
1044 | // section. But we can still wind up issuing more than one | |
1045 | // error per object file. | |
1046 | if (this->issued_non_pic_error_) | |
1047 | return; | |
1048 | object->error(_("requires unsupported dynamic reloc; " | |
1049 | "recompile with -fPIC")); | |
1050 | this->issued_non_pic_error_ = true; | |
1051 | return; | |
1052 | ||
1053 | case elfcpp::R_ARM_NONE: | |
1054 | gold_unreachable(); | |
1055 | } | |
1056 | } | |
1057 | ||
4a657b0d | 1058 | // Scan a relocation for a local symbol. |
bec53400 DK |
1059 | // FIXME: This only handles a subset of relocation types used by Android |
1060 | // on ARM v5te devices. | |
4a657b0d DK |
1061 | |
1062 | template<bool big_endian> | |
1063 | inline void | |
1064 | Target_arm<big_endian>::Scan::local(const General_options&, | |
bec53400 DK |
1065 | Symbol_table* symtab, |
1066 | Layout* layout, | |
1067 | Target_arm* target, | |
4a657b0d | 1068 | Sized_relobj<32, big_endian>* object, |
bec53400 DK |
1069 | unsigned int data_shndx, |
1070 | Output_section* output_section, | |
1071 | const elfcpp::Rel<32, big_endian>& reloc, | |
4a657b0d DK |
1072 | unsigned int r_type, |
1073 | const elfcpp::Sym<32, big_endian>&) | |
1074 | { | |
1075 | r_type = get_real_reloc_type(r_type); | |
1076 | switch (r_type) | |
1077 | { | |
1078 | case elfcpp::R_ARM_NONE: | |
1079 | break; | |
1080 | ||
bec53400 DK |
1081 | case elfcpp::R_ARM_ABS32: |
1082 | // If building a shared library (or a position-independent | |
1083 | // executable), we need to create a dynamic relocation for | |
1084 | // this location. The relocation applied at link time will | |
1085 | // apply the link-time value, so we flag the location with | |
1086 | // an R_ARM_RELATIVE relocation so the dynamic loader can | |
1087 | // relocate it easily. | |
1088 | if (parameters->options().output_is_position_independent()) | |
1089 | { | |
1090 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1091 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); | |
1092 | // If we are to add more other reloc types than R_ARM_ABS32, | |
1093 | // we need to add check_non_pic(object, r_type) here. | |
1094 | rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE, | |
1095 | output_section, data_shndx, | |
1096 | reloc.get_r_offset()); | |
1097 | } | |
1098 | break; | |
1099 | ||
1100 | case elfcpp::R_ARM_REL32: | |
1101 | case elfcpp::R_ARM_THM_CALL: | |
1102 | case elfcpp::R_ARM_CALL: | |
1103 | case elfcpp::R_ARM_PREL31: | |
1104 | case elfcpp::R_ARM_JUMP24: | |
1105 | case elfcpp::R_ARM_PLT32: | |
1106 | break; | |
1107 | ||
1108 | case elfcpp::R_ARM_GOTOFF32: | |
1109 | // We need a GOT section: | |
1110 | target->got_section(symtab, layout); | |
1111 | break; | |
1112 | ||
1113 | case elfcpp::R_ARM_BASE_PREL: | |
1114 | // FIXME: What about this? | |
1115 | break; | |
1116 | ||
1117 | case elfcpp::R_ARM_GOT_BREL: | |
1118 | { | |
1119 | // The symbol requires a GOT entry. | |
1120 | Output_data_got<32, big_endian>* got = | |
1121 | target->got_section(symtab, layout); | |
1122 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); | |
1123 | if (got->add_local(object, r_sym, GOT_TYPE_STANDARD)) | |
1124 | { | |
1125 | // If we are generating a shared object, we need to add a | |
1126 | // dynamic RELATIVE relocation for this symbol's GOT entry. | |
1127 | if (parameters->options().output_is_position_independent()) | |
1128 | { | |
1129 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1130 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); | |
1131 | rel_dyn->add_local_relative( | |
1132 | object, r_sym, elfcpp::R_ARM_RELATIVE, got, | |
1133 | object->local_got_offset(r_sym, GOT_TYPE_STANDARD)); | |
1134 | } | |
1135 | } | |
1136 | } | |
1137 | break; | |
1138 | ||
1139 | case elfcpp::R_ARM_TARGET1: | |
1140 | // This should have been mapped to another type already. | |
1141 | // Fall through. | |
1142 | case elfcpp::R_ARM_COPY: | |
1143 | case elfcpp::R_ARM_GLOB_DAT: | |
1144 | case elfcpp::R_ARM_JUMP_SLOT: | |
1145 | case elfcpp::R_ARM_RELATIVE: | |
1146 | // These are relocations which should only be seen by the | |
1147 | // dynamic linker, and should never be seen here. | |
1148 | gold_error(_("%s: unexpected reloc %u in object file"), | |
1149 | object->name().c_str(), r_type); | |
1150 | break; | |
1151 | ||
4a657b0d DK |
1152 | default: |
1153 | unsupported_reloc_local(object, r_type); | |
1154 | break; | |
1155 | } | |
1156 | } | |
1157 | ||
1158 | // Report an unsupported relocation against a global symbol. | |
1159 | ||
1160 | template<bool big_endian> | |
1161 | void | |
1162 | Target_arm<big_endian>::Scan::unsupported_reloc_global( | |
1163 | Sized_relobj<32, big_endian>* object, | |
1164 | unsigned int r_type, | |
1165 | Symbol* gsym) | |
1166 | { | |
1167 | gold_error(_("%s: unsupported reloc %u against global symbol %s"), | |
1168 | object->name().c_str(), r_type, gsym->demangled_name().c_str()); | |
1169 | } | |
1170 | ||
1171 | // Scan a relocation for a global symbol. | |
bec53400 DK |
1172 | // FIXME: This only handles a subset of relocation types used by Android |
1173 | // on ARM v5te devices. | |
4a657b0d DK |
1174 | |
1175 | template<bool big_endian> | |
1176 | inline void | |
1177 | Target_arm<big_endian>::Scan::global(const General_options&, | |
bec53400 DK |
1178 | Symbol_table* symtab, |
1179 | Layout* layout, | |
1180 | Target_arm* target, | |
4a657b0d | 1181 | Sized_relobj<32, big_endian>* object, |
bec53400 DK |
1182 | unsigned int data_shndx, |
1183 | Output_section* output_section, | |
1184 | const elfcpp::Rel<32, big_endian>& reloc, | |
4a657b0d DK |
1185 | unsigned int r_type, |
1186 | Symbol* gsym) | |
1187 | { | |
1188 | r_type = get_real_reloc_type(r_type); | |
1189 | switch (r_type) | |
1190 | { | |
1191 | case elfcpp::R_ARM_NONE: | |
1192 | break; | |
1193 | ||
bec53400 DK |
1194 | case elfcpp::R_ARM_ABS32: |
1195 | { | |
1196 | // Make a dynamic relocation if necessary. | |
1197 | if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF)) | |
1198 | { | |
1199 | if (target->may_need_copy_reloc(gsym)) | |
1200 | { | |
1201 | target->copy_reloc(symtab, layout, object, | |
1202 | data_shndx, output_section, gsym, reloc); | |
1203 | } | |
1204 | else if (gsym->can_use_relative_reloc(false)) | |
1205 | { | |
1206 | // If we are to add more other reloc types than R_ARM_ABS32, | |
1207 | // we need to add check_non_pic(object, r_type) here. | |
1208 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1209 | rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE, | |
1210 | output_section, object, | |
1211 | data_shndx, reloc.get_r_offset()); | |
1212 | } | |
1213 | else | |
1214 | { | |
1215 | // If we are to add more other reloc types than R_ARM_ABS32, | |
1216 | // we need to add check_non_pic(object, r_type) here. | |
1217 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1218 | rel_dyn->add_global(gsym, r_type, output_section, object, | |
1219 | data_shndx, reloc.get_r_offset()); | |
1220 | } | |
1221 | } | |
1222 | } | |
1223 | break; | |
1224 | ||
1225 | case elfcpp::R_ARM_REL32: | |
1226 | case elfcpp::R_ARM_PREL31: | |
1227 | { | |
1228 | // Make a dynamic relocation if necessary. | |
1229 | int flags = Symbol::NON_PIC_REF; | |
1230 | if (gsym->needs_dynamic_reloc(flags)) | |
1231 | { | |
1232 | if (target->may_need_copy_reloc(gsym)) | |
1233 | { | |
1234 | target->copy_reloc(symtab, layout, object, | |
1235 | data_shndx, output_section, gsym, reloc); | |
1236 | } | |
1237 | else | |
1238 | { | |
1239 | check_non_pic(object, r_type); | |
1240 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1241 | rel_dyn->add_global(gsym, r_type, output_section, object, | |
1242 | data_shndx, reloc.get_r_offset()); | |
1243 | } | |
1244 | } | |
1245 | } | |
1246 | break; | |
1247 | ||
1248 | case elfcpp::R_ARM_JUMP24: | |
1249 | case elfcpp::R_ARM_THM_CALL: | |
1250 | case elfcpp::R_ARM_CALL: | |
1251 | { | |
1252 | if (Target_arm<big_endian>::Scan::symbol_needs_plt_entry(gsym)) | |
1253 | target->make_plt_entry(symtab, layout, gsym); | |
1254 | // Make a dynamic relocation if necessary. | |
1255 | int flags = Symbol::NON_PIC_REF; | |
1256 | if (gsym->type() == elfcpp::STT_FUNC | |
07800fab | 1257 | || gsym->type() == elfcpp::STT_ARM_TFUNC) |
bec53400 DK |
1258 | flags |= Symbol::FUNCTION_CALL; |
1259 | if (gsym->needs_dynamic_reloc(flags)) | |
1260 | { | |
1261 | if (target->may_need_copy_reloc(gsym)) | |
1262 | { | |
1263 | target->copy_reloc(symtab, layout, object, | |
1264 | data_shndx, output_section, gsym, | |
1265 | reloc); | |
1266 | } | |
1267 | else | |
1268 | { | |
1269 | check_non_pic(object, r_type); | |
1270 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1271 | rel_dyn->add_global(gsym, r_type, output_section, object, | |
1272 | data_shndx, reloc.get_r_offset()); | |
1273 | } | |
1274 | } | |
1275 | } | |
1276 | break; | |
1277 | ||
1278 | case elfcpp::R_ARM_PLT32: | |
1279 | // If the symbol is fully resolved, this is just a relative | |
1280 | // local reloc. Otherwise we need a PLT entry. | |
1281 | if (gsym->final_value_is_known()) | |
1282 | break; | |
1283 | // If building a shared library, we can also skip the PLT entry | |
1284 | // if the symbol is defined in the output file and is protected | |
1285 | // or hidden. | |
1286 | if (gsym->is_defined() | |
1287 | && !gsym->is_from_dynobj() | |
1288 | && !gsym->is_preemptible()) | |
1289 | break; | |
1290 | target->make_plt_entry(symtab, layout, gsym); | |
1291 | break; | |
1292 | ||
1293 | case elfcpp::R_ARM_GOTOFF32: | |
1294 | // We need a GOT section. | |
1295 | target->got_section(symtab, layout); | |
1296 | break; | |
1297 | ||
1298 | case elfcpp::R_ARM_BASE_PREL: | |
1299 | // FIXME: What about this? | |
1300 | break; | |
1301 | ||
1302 | case elfcpp::R_ARM_GOT_BREL: | |
1303 | { | |
1304 | // The symbol requires a GOT entry. | |
1305 | Output_data_got<32, big_endian>* got = | |
1306 | target->got_section(symtab, layout); | |
1307 | if (gsym->final_value_is_known()) | |
1308 | got->add_global(gsym, GOT_TYPE_STANDARD); | |
1309 | else | |
1310 | { | |
1311 | // If this symbol is not fully resolved, we need to add a | |
1312 | // GOT entry with a dynamic relocation. | |
1313 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1314 | if (gsym->is_from_dynobj() | |
1315 | || gsym->is_undefined() | |
1316 | || gsym->is_preemptible()) | |
1317 | got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, | |
1318 | rel_dyn, elfcpp::R_ARM_GLOB_DAT); | |
1319 | else | |
1320 | { | |
1321 | if (got->add_global(gsym, GOT_TYPE_STANDARD)) | |
1322 | rel_dyn->add_global_relative( | |
1323 | gsym, elfcpp::R_ARM_RELATIVE, got, | |
1324 | gsym->got_offset(GOT_TYPE_STANDARD)); | |
1325 | } | |
1326 | } | |
1327 | } | |
1328 | break; | |
1329 | ||
1330 | case elfcpp::R_ARM_TARGET1: | |
1331 | // This should have been mapped to another type already. | |
1332 | // Fall through. | |
1333 | case elfcpp::R_ARM_COPY: | |
1334 | case elfcpp::R_ARM_GLOB_DAT: | |
1335 | case elfcpp::R_ARM_JUMP_SLOT: | |
1336 | case elfcpp::R_ARM_RELATIVE: | |
1337 | // These are relocations which should only be seen by the | |
1338 | // dynamic linker, and should never be seen here. | |
1339 | gold_error(_("%s: unexpected reloc %u in object file"), | |
1340 | object->name().c_str(), r_type); | |
1341 | break; | |
1342 | ||
4a657b0d DK |
1343 | default: |
1344 | unsupported_reloc_global(object, r_type, gsym); | |
1345 | break; | |
1346 | } | |
1347 | } | |
1348 | ||
1349 | // Process relocations for gc. | |
1350 | ||
1351 | template<bool big_endian> | |
1352 | void | |
1353 | Target_arm<big_endian>::gc_process_relocs(const General_options& options, | |
1354 | Symbol_table* symtab, | |
1355 | Layout* layout, | |
1356 | Sized_relobj<32, big_endian>* object, | |
1357 | unsigned int data_shndx, | |
1358 | unsigned int, | |
1359 | const unsigned char* prelocs, | |
1360 | size_t reloc_count, | |
1361 | Output_section* output_section, | |
1362 | bool needs_special_offset_handling, | |
1363 | size_t local_symbol_count, | |
1364 | const unsigned char* plocal_symbols) | |
1365 | { | |
1366 | typedef Target_arm<big_endian> Arm; | |
1367 | typedef typename Target_arm<big_endian>::Scan Scan; | |
1368 | ||
1369 | gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan>( | |
1370 | options, | |
1371 | symtab, | |
1372 | layout, | |
1373 | this, | |
1374 | object, | |
1375 | data_shndx, | |
1376 | prelocs, | |
1377 | reloc_count, | |
1378 | output_section, | |
1379 | needs_special_offset_handling, | |
1380 | local_symbol_count, | |
1381 | plocal_symbols); | |
1382 | } | |
1383 | ||
1384 | // Scan relocations for a section. | |
1385 | ||
1386 | template<bool big_endian> | |
1387 | void | |
1388 | Target_arm<big_endian>::scan_relocs(const General_options& options, | |
1389 | Symbol_table* symtab, | |
1390 | Layout* layout, | |
1391 | Sized_relobj<32, big_endian>* object, | |
1392 | unsigned int data_shndx, | |
1393 | unsigned int sh_type, | |
1394 | const unsigned char* prelocs, | |
1395 | size_t reloc_count, | |
1396 | Output_section* output_section, | |
1397 | bool needs_special_offset_handling, | |
1398 | size_t local_symbol_count, | |
1399 | const unsigned char* plocal_symbols) | |
1400 | { | |
1401 | typedef typename Target_arm<big_endian>::Scan Scan; | |
1402 | if (sh_type == elfcpp::SHT_RELA) | |
1403 | { | |
1404 | gold_error(_("%s: unsupported RELA reloc section"), | |
1405 | object->name().c_str()); | |
1406 | return; | |
1407 | } | |
1408 | ||
1409 | gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>( | |
1410 | options, | |
1411 | symtab, | |
1412 | layout, | |
1413 | this, | |
1414 | object, | |
1415 | data_shndx, | |
1416 | prelocs, | |
1417 | reloc_count, | |
1418 | output_section, | |
1419 | needs_special_offset_handling, | |
1420 | local_symbol_count, | |
1421 | plocal_symbols); | |
1422 | } | |
1423 | ||
1424 | // Finalize the sections. | |
1425 | ||
1426 | template<bool big_endian> | |
1427 | void | |
94cdfcff | 1428 | Target_arm<big_endian>::do_finalize_sections(Layout* layout) |
4a657b0d | 1429 | { |
94cdfcff DK |
1430 | // Fill in some more dynamic tags. |
1431 | Output_data_dynamic* const odyn = layout->dynamic_data(); | |
1432 | if (odyn != NULL) | |
1433 | { | |
1434 | if (this->got_plt_ != NULL) | |
1435 | odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); | |
1436 | ||
1437 | if (this->plt_ != NULL) | |
1438 | { | |
1439 | const Output_data* od = this->plt_->rel_plt(); | |
1440 | odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); | |
1441 | odyn->add_section_address(elfcpp::DT_JMPREL, od); | |
1442 | odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); | |
1443 | } | |
1444 | ||
1445 | if (this->rel_dyn_ != NULL) | |
1446 | { | |
1447 | const Output_data* od = this->rel_dyn_; | |
1448 | odyn->add_section_address(elfcpp::DT_REL, od); | |
1449 | odyn->add_section_size(elfcpp::DT_RELSZ, od); | |
1450 | odyn->add_constant(elfcpp::DT_RELENT, | |
1451 | elfcpp::Elf_sizes<32>::rel_size); | |
1452 | } | |
1453 | ||
1454 | if (!parameters->options().shared()) | |
1455 | { | |
1456 | // The value of the DT_DEBUG tag is filled in by the dynamic | |
1457 | // linker at run time, and used by the debugger. | |
1458 | odyn->add_constant(elfcpp::DT_DEBUG, 0); | |
1459 | } | |
1460 | } | |
1461 | ||
1462 | // Emit any relocs we saved in an attempt to avoid generating COPY | |
1463 | // relocs. | |
1464 | if (this->copy_relocs_.any_saved_relocs()) | |
1465 | this->copy_relocs_.emit(this->rel_dyn_section(layout)); | |
4a657b0d DK |
1466 | } |
1467 | ||
bec53400 DK |
1468 | // Return whether a direct absolute static relocation needs to be applied. |
1469 | // In cases where Scan::local() or Scan::global() has created | |
1470 | // a dynamic relocation other than R_ARM_RELATIVE, the addend | |
1471 | // of the relocation is carried in the data, and we must not | |
1472 | // apply the static relocation. | |
1473 | ||
1474 | template<bool big_endian> | |
1475 | inline bool | |
1476 | Target_arm<big_endian>::Relocate::should_apply_static_reloc( | |
1477 | const Sized_symbol<32>* gsym, | |
1478 | int ref_flags, | |
1479 | bool is_32bit, | |
1480 | Output_section* output_section) | |
1481 | { | |
1482 | // If the output section is not allocated, then we didn't call | |
1483 | // scan_relocs, we didn't create a dynamic reloc, and we must apply | |
1484 | // the reloc here. | |
1485 | if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0) | |
1486 | return true; | |
1487 | ||
1488 | // For local symbols, we will have created a non-RELATIVE dynamic | |
1489 | // relocation only if (a) the output is position independent, | |
1490 | // (b) the relocation is absolute (not pc- or segment-relative), and | |
1491 | // (c) the relocation is not 32 bits wide. | |
1492 | if (gsym == NULL) | |
1493 | return !(parameters->options().output_is_position_independent() | |
1494 | && (ref_flags & Symbol::ABSOLUTE_REF) | |
1495 | && !is_32bit); | |
1496 | ||
1497 | // For global symbols, we use the same helper routines used in the | |
1498 | // scan pass. If we did not create a dynamic relocation, or if we | |
1499 | // created a RELATIVE dynamic relocation, we should apply the static | |
1500 | // relocation. | |
1501 | bool has_dyn = gsym->needs_dynamic_reloc(ref_flags); | |
1502 | bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF) | |
1503 | && gsym->can_use_relative_reloc(ref_flags | |
1504 | & Symbol::FUNCTION_CALL); | |
1505 | return !has_dyn || is_rel; | |
1506 | } | |
1507 | ||
4a657b0d DK |
1508 | // Perform a relocation. |
1509 | ||
1510 | template<bool big_endian> | |
1511 | inline bool | |
1512 | Target_arm<big_endian>::Relocate::relocate( | |
c121c671 DK |
1513 | const Relocate_info<32, big_endian>* relinfo, |
1514 | Target_arm* target, | |
1515 | Output_section *output_section, | |
1516 | size_t relnum, | |
1517 | const elfcpp::Rel<32, big_endian>& rel, | |
4a657b0d | 1518 | unsigned int r_type, |
c121c671 DK |
1519 | const Sized_symbol<32>* gsym, |
1520 | const Symbol_value<32>* psymval, | |
1521 | unsigned char* view, | |
1522 | elfcpp::Elf_types<32>::Elf_Addr address, | |
4a657b0d DK |
1523 | section_size_type /* view_size */ ) |
1524 | { | |
c121c671 DK |
1525 | typedef Arm_relocate_functions<big_endian> Arm_relocate_functions; |
1526 | ||
1527 | r_type = get_real_reloc_type(r_type); | |
1528 | ||
1529 | // If this the symbol may be a Thumb function, set thumb bit to 1. | |
1530 | bool has_thumb_bit = ((gsym != NULL) | |
1531 | && (gsym->type() == elfcpp::STT_FUNC | |
1532 | || gsym->type() == elfcpp::STT_ARM_TFUNC)); | |
1533 | ||
1534 | // Pick the value to use for symbols defined in shared objects. | |
1535 | Symbol_value<32> symval; | |
1536 | if (gsym != NULL | |
1537 | && gsym->use_plt_offset(reloc_is_non_pic(r_type))) | |
1538 | { | |
1539 | symval.set_output_value(target->plt_section()->address() | |
1540 | + gsym->plt_offset()); | |
1541 | psymval = &symval; | |
1542 | has_thumb_bit = 0; | |
1543 | } | |
1544 | ||
1545 | const Sized_relobj<32, big_endian>* object = relinfo->object; | |
1546 | ||
1547 | // Get the GOT offset if needed. | |
1548 | // The GOT pointer points to the end of the GOT section. | |
1549 | // We need to subtract the size of the GOT section to get | |
1550 | // the actual offset to use in the relocation. | |
1551 | bool have_got_offset = false; | |
1552 | unsigned int got_offset = 0; | |
1553 | switch (r_type) | |
1554 | { | |
1555 | case elfcpp::R_ARM_GOT_BREL: | |
1556 | if (gsym != NULL) | |
1557 | { | |
1558 | gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD)); | |
1559 | got_offset = (gsym->got_offset(GOT_TYPE_STANDARD) | |
1560 | - target->got_size()); | |
1561 | } | |
1562 | else | |
1563 | { | |
1564 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); | |
1565 | gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD)); | |
1566 | got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD) | |
1567 | - target->got_size()); | |
1568 | } | |
1569 | have_got_offset = true; | |
1570 | break; | |
1571 | ||
1572 | default: | |
1573 | break; | |
1574 | } | |
1575 | ||
1576 | typename Arm_relocate_functions::Status reloc_status = | |
1577 | Arm_relocate_functions::STATUS_OKAY; | |
4a657b0d DK |
1578 | switch (r_type) |
1579 | { | |
1580 | case elfcpp::R_ARM_NONE: | |
1581 | break; | |
1582 | ||
c121c671 DK |
1583 | case elfcpp::R_ARM_ABS32: |
1584 | if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, | |
1585 | output_section)) | |
1586 | reloc_status = Arm_relocate_functions::abs32(view, object, psymval, | |
1587 | has_thumb_bit); | |
1588 | break; | |
1589 | ||
1590 | case elfcpp::R_ARM_REL32: | |
1591 | reloc_status = Arm_relocate_functions::rel32(view, object, psymval, | |
1592 | address, has_thumb_bit); | |
1593 | break; | |
1594 | ||
1595 | case elfcpp::R_ARM_THM_CALL: | |
1596 | reloc_status = Arm_relocate_functions::thm_call(view, object, psymval, | |
1597 | address, has_thumb_bit); | |
1598 | break; | |
1599 | ||
1600 | case elfcpp::R_ARM_GOTOFF32: | |
1601 | { | |
1602 | elfcpp::Elf_types<32>::Elf_Addr got_origin; | |
1603 | got_origin = target->got_plt_section()->address(); | |
1604 | reloc_status = Arm_relocate_functions::rel32(view, object, psymval, | |
1605 | got_origin, has_thumb_bit); | |
1606 | } | |
1607 | break; | |
1608 | ||
1609 | case elfcpp::R_ARM_BASE_PREL: | |
1610 | { | |
1611 | uint32_t origin; | |
1612 | // Get the addressing origin of the output segment defining the | |
1613 | // symbol gsym (AAELF 4.6.1.2 Relocation types) | |
1614 | gold_assert(gsym != NULL); | |
1615 | if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT) | |
1616 | origin = gsym->output_segment()->vaddr(); | |
1617 | else if (gsym->source () == Symbol::IN_OUTPUT_DATA) | |
1618 | origin = gsym->output_data()->address(); | |
1619 | else | |
1620 | { | |
1621 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), | |
1622 | _("cannot find origin of R_ARM_BASE_PREL")); | |
1623 | return true; | |
1624 | } | |
1625 | reloc_status = Arm_relocate_functions::base_prel(view, origin, address); | |
1626 | } | |
1627 | break; | |
1628 | ||
1629 | case elfcpp::R_ARM_GOT_BREL: | |
1630 | gold_assert(have_got_offset); | |
1631 | reloc_status = Arm_relocate_functions::got_brel(view, got_offset); | |
1632 | break; | |
1633 | ||
1634 | case elfcpp::R_ARM_PLT32: | |
1635 | gold_assert(gsym == NULL | |
1636 | || gsym->has_plt_offset() | |
1637 | || gsym->final_value_is_known() | |
1638 | || (gsym->is_defined() | |
1639 | && !gsym->is_from_dynobj() | |
1640 | && !gsym->is_preemptible())); | |
1641 | reloc_status = Arm_relocate_functions::plt32(view, object, psymval, | |
1642 | address, has_thumb_bit); | |
1643 | break; | |
1644 | ||
1645 | case elfcpp::R_ARM_CALL: | |
1646 | reloc_status = Arm_relocate_functions::call(view, object, psymval, | |
1647 | address, has_thumb_bit); | |
1648 | break; | |
1649 | ||
1650 | case elfcpp::R_ARM_JUMP24: | |
1651 | reloc_status = Arm_relocate_functions::jump24(view, object, psymval, | |
1652 | address, has_thumb_bit); | |
1653 | break; | |
1654 | ||
1655 | case elfcpp::R_ARM_PREL31: | |
1656 | reloc_status = Arm_relocate_functions::prel31(view, object, psymval, | |
1657 | address, has_thumb_bit); | |
1658 | break; | |
1659 | ||
1660 | case elfcpp::R_ARM_TARGET1: | |
1661 | // This should have been mapped to another type already. | |
1662 | // Fall through. | |
1663 | case elfcpp::R_ARM_COPY: | |
1664 | case elfcpp::R_ARM_GLOB_DAT: | |
1665 | case elfcpp::R_ARM_JUMP_SLOT: | |
1666 | case elfcpp::R_ARM_RELATIVE: | |
1667 | // These are relocations which should only be seen by the | |
1668 | // dynamic linker, and should never be seen here. | |
1669 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), | |
1670 | _("unexpected reloc %u in object file"), | |
1671 | r_type); | |
1672 | break; | |
1673 | ||
1674 | default: | |
1675 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), | |
1676 | _("unsupported reloc %u"), | |
1677 | r_type); | |
1678 | break; | |
1679 | } | |
1680 | ||
1681 | // Report any errors. | |
1682 | switch (reloc_status) | |
1683 | { | |
1684 | case Arm_relocate_functions::STATUS_OKAY: | |
1685 | break; | |
1686 | case Arm_relocate_functions::STATUS_OVERFLOW: | |
1687 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), | |
1688 | _("relocation overflow in relocation %u"), | |
1689 | r_type); | |
1690 | break; | |
1691 | case Arm_relocate_functions::STATUS_BAD_RELOC: | |
1692 | gold_error_at_location( | |
1693 | relinfo, | |
1694 | relnum, | |
1695 | rel.get_r_offset(), | |
1696 | _("unexpected opcode while processing relocation %u"), | |
1697 | r_type); | |
1698 | break; | |
4a657b0d DK |
1699 | default: |
1700 | gold_unreachable(); | |
1701 | } | |
1702 | ||
1703 | return true; | |
1704 | } | |
1705 | ||
1706 | // Relocate section data. | |
1707 | ||
1708 | template<bool big_endian> | |
1709 | void | |
1710 | Target_arm<big_endian>::relocate_section( | |
1711 | const Relocate_info<32, big_endian>* relinfo, | |
1712 | unsigned int sh_type, | |
1713 | const unsigned char* prelocs, | |
1714 | size_t reloc_count, | |
1715 | Output_section* output_section, | |
1716 | bool needs_special_offset_handling, | |
1717 | unsigned char* view, | |
1718 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1719 | section_size_type view_size) | |
1720 | { | |
1721 | typedef typename Target_arm<big_endian>::Relocate Arm_relocate; | |
1722 | gold_assert(sh_type == elfcpp::SHT_REL); | |
1723 | ||
1724 | gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL, | |
1725 | Arm_relocate>( | |
1726 | relinfo, | |
1727 | this, | |
1728 | prelocs, | |
1729 | reloc_count, | |
1730 | output_section, | |
1731 | needs_special_offset_handling, | |
1732 | view, | |
1733 | address, | |
1734 | view_size); | |
1735 | } | |
1736 | ||
1737 | // Return the size of a relocation while scanning during a relocatable | |
1738 | // link. | |
1739 | ||
1740 | template<bool big_endian> | |
1741 | unsigned int | |
1742 | Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc( | |
1743 | unsigned int r_type, | |
1744 | Relobj* object) | |
1745 | { | |
1746 | r_type = get_real_reloc_type(r_type); | |
1747 | switch (r_type) | |
1748 | { | |
1749 | case elfcpp::R_ARM_NONE: | |
1750 | return 0; | |
1751 | ||
1752 | case elfcpp::R_ARM_ABS32: | |
1753 | case elfcpp::R_ARM_REL32: | |
1754 | case elfcpp::R_ARM_THM_CALL: | |
1755 | case elfcpp::R_ARM_GOTOFF32: | |
1756 | case elfcpp::R_ARM_BASE_PREL: | |
1757 | case elfcpp::R_ARM_GOT_BREL: | |
1758 | case elfcpp::R_ARM_PLT32: | |
1759 | case elfcpp::R_ARM_CALL: | |
1760 | case elfcpp::R_ARM_JUMP24: | |
1761 | case elfcpp::R_ARM_PREL31: | |
1762 | return 4; | |
1763 | ||
1764 | case elfcpp::R_ARM_TARGET1: | |
1765 | // This should have been mapped to another type already. | |
1766 | // Fall through. | |
1767 | case elfcpp::R_ARM_COPY: | |
1768 | case elfcpp::R_ARM_GLOB_DAT: | |
1769 | case elfcpp::R_ARM_JUMP_SLOT: | |
1770 | case elfcpp::R_ARM_RELATIVE: | |
1771 | // These are relocations which should only be seen by the | |
1772 | // dynamic linker, and should never be seen here. | |
1773 | gold_error(_("%s: unexpected reloc %u in object file"), | |
1774 | object->name().c_str(), r_type); | |
1775 | return 0; | |
1776 | ||
1777 | default: | |
1778 | object->error(_("unsupported reloc %u in object file"), r_type); | |
1779 | return 0; | |
1780 | } | |
1781 | } | |
1782 | ||
1783 | // Scan the relocs during a relocatable link. | |
1784 | ||
1785 | template<bool big_endian> | |
1786 | void | |
1787 | Target_arm<big_endian>::scan_relocatable_relocs( | |
1788 | const General_options& options, | |
1789 | Symbol_table* symtab, | |
1790 | Layout* layout, | |
1791 | Sized_relobj<32, big_endian>* object, | |
1792 | unsigned int data_shndx, | |
1793 | unsigned int sh_type, | |
1794 | const unsigned char* prelocs, | |
1795 | size_t reloc_count, | |
1796 | Output_section* output_section, | |
1797 | bool needs_special_offset_handling, | |
1798 | size_t local_symbol_count, | |
1799 | const unsigned char* plocal_symbols, | |
1800 | Relocatable_relocs* rr) | |
1801 | { | |
1802 | gold_assert(sh_type == elfcpp::SHT_REL); | |
1803 | ||
1804 | typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL, | |
1805 | Relocatable_size_for_reloc> Scan_relocatable_relocs; | |
1806 | ||
1807 | gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL, | |
1808 | Scan_relocatable_relocs>( | |
1809 | options, | |
1810 | symtab, | |
1811 | layout, | |
1812 | object, | |
1813 | data_shndx, | |
1814 | prelocs, | |
1815 | reloc_count, | |
1816 | output_section, | |
1817 | needs_special_offset_handling, | |
1818 | local_symbol_count, | |
1819 | plocal_symbols, | |
1820 | rr); | |
1821 | } | |
1822 | ||
1823 | // Relocate a section during a relocatable link. | |
1824 | ||
1825 | template<bool big_endian> | |
1826 | void | |
1827 | Target_arm<big_endian>::relocate_for_relocatable( | |
1828 | const Relocate_info<32, big_endian>* relinfo, | |
1829 | unsigned int sh_type, | |
1830 | const unsigned char* prelocs, | |
1831 | size_t reloc_count, | |
1832 | Output_section* output_section, | |
1833 | off_t offset_in_output_section, | |
1834 | const Relocatable_relocs* rr, | |
1835 | unsigned char* view, | |
1836 | elfcpp::Elf_types<32>::Elf_Addr view_address, | |
1837 | section_size_type view_size, | |
1838 | unsigned char* reloc_view, | |
1839 | section_size_type reloc_view_size) | |
1840 | { | |
1841 | gold_assert(sh_type == elfcpp::SHT_REL); | |
1842 | ||
1843 | gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>( | |
1844 | relinfo, | |
1845 | prelocs, | |
1846 | reloc_count, | |
1847 | output_section, | |
1848 | offset_in_output_section, | |
1849 | rr, | |
1850 | view, | |
1851 | view_address, | |
1852 | view_size, | |
1853 | reloc_view, | |
1854 | reloc_view_size); | |
1855 | } | |
1856 | ||
94cdfcff DK |
1857 | // Return the value to use for a dynamic symbol which requires special |
1858 | // treatment. This is how we support equality comparisons of function | |
1859 | // pointers across shared library boundaries, as described in the | |
1860 | // processor specific ABI supplement. | |
1861 | ||
4a657b0d DK |
1862 | template<bool big_endian> |
1863 | uint64_t | |
94cdfcff | 1864 | Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const |
4a657b0d | 1865 | { |
94cdfcff DK |
1866 | gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); |
1867 | return this->plt_section()->address() + gsym->plt_offset(); | |
4a657b0d DK |
1868 | } |
1869 | ||
1870 | // Map platform-specific relocs to real relocs | |
1871 | // | |
1872 | template<bool big_endian> | |
1873 | unsigned int | |
1874 | Target_arm<big_endian>::get_real_reloc_type (unsigned int r_type) | |
1875 | { | |
1876 | switch (r_type) | |
1877 | { | |
1878 | case elfcpp::R_ARM_TARGET1: | |
1879 | // This is either R_ARM_ABS32 or R_ARM_REL32; | |
1880 | return elfcpp::R_ARM_ABS32; | |
1881 | ||
1882 | case elfcpp::R_ARM_TARGET2: | |
1883 | // This can be any reloc type but ususally is R_ARM_GOT_PREL | |
1884 | return elfcpp::R_ARM_GOT_PREL; | |
1885 | ||
1886 | default: | |
1887 | return r_type; | |
1888 | } | |
1889 | } | |
1890 | ||
1891 | // The selector for arm object files. | |
1892 | ||
1893 | template<bool big_endian> | |
1894 | class Target_selector_arm : public Target_selector | |
1895 | { | |
1896 | public: | |
1897 | Target_selector_arm() | |
1898 | : Target_selector(elfcpp::EM_ARM, 32, big_endian, | |
1899 | (big_endian ? "elf32-bigarm" : "elf32-littlearm")) | |
1900 | { } | |
1901 | ||
1902 | Target* | |
1903 | do_instantiate_target() | |
1904 | { return new Target_arm<big_endian>(); } | |
1905 | }; | |
1906 | ||
1907 | Target_selector_arm<false> target_selector_arm; | |
1908 | Target_selector_arm<true> target_selector_armbe; | |
1909 | ||
1910 | } // End anonymous namespace. |