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fd0de36e | 1 | /* Linux bpf specific support for 64-bit ELF |
b3adc24a | 2 | Copyright (C) 2019-2020 Free Software Foundation, Inc. |
fd0de36e JM |
3 | Contributed by Oracle Inc. |
4 | ||
5 | This file is part of BFD, the Binary File Descriptor library. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
20 | MA 02110-1301, USA. */ | |
21 | ||
22 | #include "sysdep.h" | |
23 | #include "bfd.h" | |
24 | #include "libbfd.h" | |
25 | #include "elf-bfd.h" | |
26 | #include "elf/bpf.h" | |
27 | #include "libiberty.h" | |
28 | ||
29 | /* In case we're on a 32-bit machine, construct a 64-bit "-1" value. */ | |
30 | #define MINUS_ONE (~ (bfd_vma) 0) | |
31 | ||
32 | #define BASEADDR(SEC) ((SEC)->output_section->vma + (SEC)->output_offset) | |
33 | ||
3ee9565c DF |
34 | static bfd_reloc_status_type bpf_elf_generic_reloc |
35 | (bfd *, arelent *, asymbol *, void *, asection *, bfd *, char **); | |
36 | ||
fd0de36e JM |
37 | /* Relocation tables. */ |
38 | static reloc_howto_type bpf_elf_howto_table [] = | |
39 | { | |
40 | /* This reloc does nothing. */ | |
41 | HOWTO (R_BPF_NONE, /* type */ | |
42 | 0, /* rightshift */ | |
43 | 3, /* size (0 = byte, 1 = short, 2 = long) */ | |
44 | 0, /* bitsize */ | |
45 | FALSE, /* pc_relative */ | |
46 | 0, /* bitpos */ | |
47 | complain_overflow_dont, /* complain_on_overflow */ | |
3ee9565c | 48 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e JM |
49 | "R_BPF_NONE", /* name */ |
50 | FALSE, /* partial_inplace */ | |
51 | 0, /* src_mask */ | |
52 | 0, /* dst_mask */ | |
53 | FALSE), /* pcrel_offset */ | |
54 | ||
55 | /* 64-immediate in LDDW instruction. */ | |
56 | HOWTO (R_BPF_INSN_64, /* type */ | |
57 | 0, /* rightshift */ | |
58 | 4, /* size (0 = byte, 1 = short, 2 = long) */ | |
59 | 64, /* bitsize */ | |
60 | FALSE, /* pc_relative */ | |
3ee9565c | 61 | 32, /* bitpos */ |
fd0de36e | 62 | complain_overflow_signed, /* complain_on_overflow */ |
3ee9565c | 63 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e | 64 | "R_BPF_INSN_64", /* name */ |
3ee9565c DF |
65 | TRUE, /* partial_inplace */ |
66 | MINUS_ONE, /* src_mask */ | |
fd0de36e JM |
67 | MINUS_ONE, /* dst_mask */ |
68 | TRUE), /* pcrel_offset */ | |
69 | ||
3ee9565c | 70 | /* 32-immediate in many instructions. */ |
fd0de36e JM |
71 | HOWTO (R_BPF_INSN_32, /* type */ |
72 | 0, /* rightshift */ | |
73 | 2, /* size (0 = byte, 1 = short, 2 = long) */ | |
74 | 32, /* bitsize */ | |
75 | FALSE, /* pc_relative */ | |
3ee9565c | 76 | 32, /* bitpos */ |
fd0de36e | 77 | complain_overflow_signed, /* complain_on_overflow */ |
3ee9565c | 78 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e | 79 | "R_BPF_INSN_32", /* name */ |
3ee9565c DF |
80 | TRUE, /* partial_inplace */ |
81 | 0xffffffff, /* src_mask */ | |
fd0de36e JM |
82 | 0xffffffff, /* dst_mask */ |
83 | TRUE), /* pcrel_offset */ | |
84 | ||
85 | /* 16-bit offsets in instructions. */ | |
86 | HOWTO (R_BPF_INSN_16, /* type */ | |
87 | 0, /* rightshift */ | |
88 | 1, /* size (0 = byte, 1 = short, 2 = long) */ | |
89 | 16, /* bitsize */ | |
90 | FALSE, /* pc_relative */ | |
3ee9565c | 91 | 16, /* bitpos */ |
fd0de36e | 92 | complain_overflow_signed, /* complain_on_overflow */ |
3ee9565c | 93 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e | 94 | "R_BPF_INSN_16", /* name */ |
3ee9565c DF |
95 | TRUE, /* partial_inplace */ |
96 | 0x0000ffff, /* src_mask */ | |
fd0de36e JM |
97 | 0x0000ffff, /* dst_mask */ |
98 | TRUE), /* pcrel_offset */ | |
99 | ||
100 | /* 16-bit PC-relative address in jump instructions. */ | |
101 | HOWTO (R_BPF_INSN_DISP16, /* type */ | |
102 | 0, /* rightshift */ | |
103 | 1, /* size (0 = byte, 1 = short, 2 = long) */ | |
104 | 16, /* bitsize */ | |
105 | TRUE, /* pc_relative */ | |
3ee9565c | 106 | 16, /* bitpos */ |
fd0de36e | 107 | complain_overflow_signed, /* complain_on_overflow */ |
3ee9565c | 108 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e | 109 | "R_BPF_INSN_DISP16", /* name */ |
3ee9565c | 110 | TRUE, /* partial_inplace */ |
fd0de36e JM |
111 | 0xffff, /* src_mask */ |
112 | 0xffff, /* dst_mask */ | |
113 | TRUE), /* pcrel_offset */ | |
114 | ||
115 | HOWTO (R_BPF_DATA_8_PCREL, | |
116 | 0, /* rightshift */ | |
117 | 0, /* size (0 = byte, 1 = short, 2 = long) */ | |
118 | 8, /* bitsize */ | |
119 | TRUE, /* pc_relative */ | |
120 | 0, /* bitpos */ | |
121 | complain_overflow_signed, /* complain_on_overflow */ | |
3ee9565c | 122 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e | 123 | "R_BPF_8_PCREL", /* name */ |
3ee9565c DF |
124 | TRUE, /* partial_inplace */ |
125 | 0xff, /* src_mask */ | |
fd0de36e JM |
126 | 0xff, /* dst_mask */ |
127 | TRUE), /* pcrel_offset */ | |
128 | ||
129 | HOWTO (R_BPF_DATA_16_PCREL, | |
130 | 0, /* rightshift */ | |
131 | 1, /* size (0 = byte, 1 = short, 2 = long) */ | |
132 | 16, /* bitsize */ | |
133 | TRUE, /* pc_relative */ | |
134 | 0, /* bitpos */ | |
135 | complain_overflow_signed, /* complain_on_overflow */ | |
3ee9565c | 136 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e JM |
137 | "R_BPF_16_PCREL", /* name */ |
138 | FALSE, /* partial_inplace */ | |
3ee9565c | 139 | 0xffff, /* src_mask */ |
fd0de36e JM |
140 | 0xffff, /* dst_mask */ |
141 | TRUE), /* pcrel_offset */ | |
142 | ||
143 | HOWTO (R_BPF_DATA_32_PCREL, | |
144 | 0, /* rightshift */ | |
145 | 2, /* size (0 = byte, 1 = short, 2 = long) */ | |
146 | 32, /* bitsize */ | |
147 | TRUE, /* pc_relative */ | |
148 | 0, /* bitpos */ | |
149 | complain_overflow_signed, /* complain_on_overflow */ | |
3ee9565c | 150 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e JM |
151 | "R_BPF_32_PCREL", /* name */ |
152 | FALSE, /* partial_inplace */ | |
3ee9565c | 153 | 0xffffffff, /* src_mask */ |
fd0de36e JM |
154 | 0xffffffff, /* dst_mask */ |
155 | TRUE), /* pcrel_offset */ | |
156 | ||
157 | HOWTO (R_BPF_DATA_8, | |
158 | 0, /* rightshift */ | |
159 | 0, /* size (0 = byte, 1 = short, 2 = long) */ | |
160 | 8, /* bitsize */ | |
161 | FALSE, /* pc_relative */ | |
162 | 0, /* bitpos */ | |
163 | complain_overflow_unsigned, /* complain_on_overflow */ | |
3ee9565c | 164 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e | 165 | "R_BPF_DATA_8", /* name */ |
3ee9565c DF |
166 | TRUE, /* partial_inplace */ |
167 | 0xff, /* src_mask */ | |
fd0de36e JM |
168 | 0xff, /* dst_mask */ |
169 | FALSE), /* pcrel_offset */ | |
170 | ||
171 | HOWTO (R_BPF_DATA_16, | |
172 | 0, /* rightshift */ | |
173 | 1, /* size (0 = byte, 1 = short, 2 = long) */ | |
174 | 16, /* bitsize */ | |
175 | FALSE, /* pc_relative */ | |
176 | 0, /* bitpos */ | |
177 | complain_overflow_unsigned, /* complain_on_overflow */ | |
3ee9565c | 178 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e JM |
179 | "R_BPF_DATA_16", /* name */ |
180 | FALSE, /* partial_inplace */ | |
3ee9565c | 181 | 0xffff, /* src_mask */ |
fd0de36e JM |
182 | 0xffff, /* dst_mask */ |
183 | FALSE), /* pcrel_offset */ | |
184 | ||
185 | /* 32-bit PC-relative address in call instructions. */ | |
186 | HOWTO (R_BPF_INSN_DISP32, /* type */ | |
187 | 0, /* rightshift */ | |
188 | 2, /* size (0 = byte, 1 = short, 2 = long) */ | |
189 | 32, /* bitsize */ | |
190 | TRUE, /* pc_relative */ | |
3ee9565c | 191 | 32, /* bitpos */ |
fd0de36e | 192 | complain_overflow_signed, /* complain_on_overflow */ |
3ee9565c | 193 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e | 194 | "R_BPF_INSN_DISP32", /* name */ |
3ee9565c | 195 | TRUE, /* partial_inplace */ |
fd0de36e JM |
196 | 0xffffffff, /* src_mask */ |
197 | 0xffffffff, /* dst_mask */ | |
198 | TRUE), /* pcrel_offset */ | |
199 | ||
200 | /* 32-bit data. */ | |
201 | HOWTO (R_BPF_DATA_32, /* type */ | |
202 | 0, /* rightshift */ | |
203 | 2, /* size (0 = byte, 1 = short, 2 = long) */ | |
204 | 32, /* bitsize */ | |
205 | FALSE, /* pc_relative */ | |
206 | 0, /* bitpos */ | |
207 | complain_overflow_bitfield, /* complain_on_overflow */ | |
3ee9565c | 208 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e JM |
209 | "R_BPF_DATA_32", /* name */ |
210 | FALSE, /* partial_inplace */ | |
3ee9565c | 211 | 0xffffffff, /* src_mask */ |
fd0de36e JM |
212 | 0xffffffff, /* dst_mask */ |
213 | TRUE), /* pcrel_offset */ | |
214 | ||
215 | /* 64-bit data. */ | |
216 | HOWTO (R_BPF_DATA_64, /* type */ | |
217 | 0, /* rightshift */ | |
218 | 4, /* size (0 = byte, 1 = short, 2 = long) */ | |
219 | 64, /* bitsize */ | |
220 | FALSE, /* pc_relative */ | |
221 | 0, /* bitpos */ | |
222 | complain_overflow_bitfield, /* complain_on_overflow */ | |
3ee9565c | 223 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e JM |
224 | "R_BPF_DATA_64", /* name */ |
225 | FALSE, /* partial_inplace */ | |
226 | 0, /* src_mask */ | |
227 | MINUS_ONE, /* dst_mask */ | |
228 | TRUE), /* pcrel_offset */ | |
229 | ||
230 | HOWTO (R_BPF_DATA_64_PCREL, | |
231 | 0, /* rightshift */ | |
232 | 4, /* size (0 = byte, 1 = short, 2 = long) */ | |
233 | 64, /* bitsize */ | |
234 | TRUE, /* pc_relative */ | |
235 | 0, /* bitpos */ | |
236 | complain_overflow_signed, /* complain_on_overflow */ | |
3ee9565c | 237 | bpf_elf_generic_reloc, /* special_function */ |
fd0de36e JM |
238 | "R_BPF_64_PCREL", /* name */ |
239 | FALSE, /* partial_inplace */ | |
3ee9565c | 240 | MINUS_ONE, /* src_mask */ |
fd0de36e JM |
241 | MINUS_ONE, /* dst_mask */ |
242 | TRUE), /* pcrel_offset */ | |
243 | }; | |
244 | #undef AHOW | |
245 | ||
246 | /* Map BFD reloc types to bpf ELF reloc types. */ | |
247 | ||
248 | static reloc_howto_type * | |
249 | bpf_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED, | |
250 | bfd_reloc_code_real_type code) | |
251 | { | |
fc8de8e2 JM |
252 | /* Note that the bpf_elf_howto_table is indexed by the R_ constants. |
253 | Thus, the order that the howto records appear in the table *must* | |
254 | match the order of the relocation types defined in | |
fd0de36e JM |
255 | include/elf/bpf.h. */ |
256 | ||
257 | switch (code) | |
258 | { | |
259 | case BFD_RELOC_NONE: | |
260 | return &bpf_elf_howto_table[ (int) R_BPF_NONE]; | |
261 | ||
262 | case BFD_RELOC_8_PCREL: | |
263 | return &bpf_elf_howto_table[ (int) R_BPF_DATA_8_PCREL]; | |
264 | case BFD_RELOC_16_PCREL: | |
265 | return &bpf_elf_howto_table[ (int) R_BPF_DATA_16_PCREL]; | |
266 | case BFD_RELOC_32_PCREL: | |
267 | return &bpf_elf_howto_table[ (int) R_BPF_DATA_32_PCREL]; | |
268 | case BFD_RELOC_64_PCREL: | |
269 | return &bpf_elf_howto_table[ (int) R_BPF_DATA_64_PCREL]; | |
270 | ||
271 | case BFD_RELOC_8: | |
272 | return &bpf_elf_howto_table[ (int) R_BPF_DATA_8]; | |
273 | case BFD_RELOC_16: | |
274 | return &bpf_elf_howto_table[ (int) R_BPF_DATA_16]; | |
275 | case BFD_RELOC_32: | |
276 | return &bpf_elf_howto_table[ (int) R_BPF_DATA_32]; | |
277 | case BFD_RELOC_64: | |
278 | return &bpf_elf_howto_table[ (int) R_BPF_DATA_64]; | |
279 | ||
280 | case BFD_RELOC_BPF_64: | |
281 | return &bpf_elf_howto_table[ (int) R_BPF_INSN_64]; | |
282 | case BFD_RELOC_BPF_32: | |
283 | return &bpf_elf_howto_table[ (int) R_BPF_INSN_32]; | |
284 | case BFD_RELOC_BPF_16: | |
285 | return &bpf_elf_howto_table[ (int) R_BPF_INSN_16]; | |
286 | case BFD_RELOC_BPF_DISP16: | |
287 | return &bpf_elf_howto_table[ (int) R_BPF_INSN_DISP16]; | |
288 | case BFD_RELOC_BPF_DISP32: | |
289 | return &bpf_elf_howto_table[ (int) R_BPF_INSN_DISP32]; | |
290 | ||
291 | default: | |
292 | /* Pacify gcc -Wall. */ | |
293 | return NULL; | |
294 | } | |
295 | return NULL; | |
296 | } | |
297 | ||
298 | /* Map BFD reloc names to bpf ELF reloc names. */ | |
299 | ||
300 | static reloc_howto_type * | |
301 | bpf_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, const char *r_name) | |
302 | { | |
303 | unsigned int i; | |
304 | ||
305 | for (i = 0; i < ARRAY_SIZE (bpf_elf_howto_table); i++) | |
306 | if (bpf_elf_howto_table[i].name != NULL | |
307 | && strcasecmp (bpf_elf_howto_table[i].name, r_name) == 0) | |
308 | return &bpf_elf_howto_table[i]; | |
309 | ||
310 | return NULL; | |
311 | } | |
312 | ||
313 | /* Set the howto pointer for a bpf reloc. */ | |
314 | ||
315 | static bfd_boolean | |
316 | bpf_info_to_howto (bfd *abfd, arelent *bfd_reloc, | |
317 | Elf_Internal_Rela *elf_reloc) | |
318 | { | |
319 | unsigned int r_type; | |
320 | ||
321 | r_type = ELF64_R_TYPE (elf_reloc->r_info); | |
322 | if (r_type >= (unsigned int) R_BPF_max) | |
323 | { | |
324 | /* xgettext:c-format */ | |
325 | _bfd_error_handler (_("%pB: unsupported relocation type %#x"), | |
326 | abfd, r_type); | |
327 | bfd_set_error (bfd_error_bad_value); | |
328 | return FALSE; | |
329 | } | |
330 | ||
331 | bfd_reloc->howto = &bpf_elf_howto_table [r_type]; | |
332 | return TRUE; | |
333 | } | |
334 | ||
fc8de8e2 JM |
335 | /* Relocate an eBPF ELF section. |
336 | ||
337 | The RELOCATE_SECTION function is called by the new ELF backend linker | |
338 | to handle the relocations for a section. | |
339 | ||
340 | The relocs are always passed as Rela structures; if the section | |
341 | actually uses Rel structures, the r_addend field will always be | |
342 | zero. | |
343 | ||
344 | This function is responsible for adjusting the section contents as | |
345 | necessary, and (if using Rela relocs and generating a relocatable | |
346 | output file) adjusting the reloc addend as necessary. | |
347 | ||
348 | This function does not have to worry about setting the reloc | |
349 | address or the reloc symbol index. | |
350 | ||
351 | LOCAL_SYMS is a pointer to the swapped in local symbols. | |
352 | ||
353 | LOCAL_SECTIONS is an array giving the section in the input file | |
354 | corresponding to the st_shndx field of each local symbol. | |
355 | ||
356 | The global hash table entry for the global symbols can be found | |
357 | via elf_sym_hashes (input_bfd). | |
358 | ||
359 | When generating relocatable output, this function must handle | |
360 | STB_LOCAL/STT_SECTION symbols specially. The output symbol is | |
361 | going to be the section symbol corresponding to the output | |
362 | section, which means that the addend must be adjusted | |
363 | accordingly. */ | |
364 | ||
365 | #define sec_addr(sec) ((sec)->output_section->vma + (sec)->output_offset) | |
366 | ||
367 | static bfd_boolean | |
368 | bpf_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED, | |
369 | struct bfd_link_info *info, | |
370 | bfd *input_bfd, | |
371 | asection *input_section, | |
372 | bfd_byte *contents, | |
373 | Elf_Internal_Rela *relocs, | |
374 | Elf_Internal_Sym *local_syms, | |
375 | asection **local_sections) | |
376 | { | |
377 | Elf_Internal_Shdr *symtab_hdr; | |
378 | struct elf_link_hash_entry **sym_hashes; | |
379 | Elf_Internal_Rela *rel; | |
380 | Elf_Internal_Rela *relend; | |
381 | ||
382 | symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr; | |
383 | sym_hashes = elf_sym_hashes (input_bfd); | |
384 | relend = relocs + input_section->reloc_count; | |
385 | ||
386 | for (rel = relocs; rel < relend; rel ++) | |
387 | { | |
388 | reloc_howto_type * howto; | |
389 | unsigned long r_symndx; | |
390 | Elf_Internal_Sym * sym; | |
391 | asection * sec; | |
392 | struct elf_link_hash_entry * h; | |
393 | bfd_vma relocation; | |
394 | bfd_reloc_status_type r; | |
395 | const char * name = NULL; | |
396 | int r_type ATTRIBUTE_UNUSED; | |
3ee9565c DF |
397 | bfd_signed_vma addend; |
398 | bfd_byte * where; | |
fc8de8e2 JM |
399 | |
400 | r_type = ELF64_R_TYPE (rel->r_info); | |
401 | r_symndx = ELF64_R_SYM (rel->r_info); | |
402 | howto = bpf_elf_howto_table + ELF64_R_TYPE (rel->r_info); | |
403 | h = NULL; | |
404 | sym = NULL; | |
405 | sec = NULL; | |
3ee9565c | 406 | where = contents + rel->r_offset; |
fc8de8e2 JM |
407 | |
408 | if (r_symndx < symtab_hdr->sh_info) | |
409 | { | |
410 | sym = local_syms + r_symndx; | |
411 | sec = local_sections [r_symndx]; | |
412 | relocation = BASEADDR (sec) + sym->st_value; | |
413 | ||
414 | name = bfd_elf_string_from_elf_section | |
415 | (input_bfd, symtab_hdr->sh_link, sym->st_name); | |
fd361982 | 416 | name = name == NULL ? bfd_section_name (sec) : name; |
fc8de8e2 JM |
417 | } |
418 | else | |
419 | { | |
420 | bfd_boolean warned ATTRIBUTE_UNUSED; | |
421 | bfd_boolean unresolved_reloc ATTRIBUTE_UNUSED; | |
422 | bfd_boolean ignored ATTRIBUTE_UNUSED; | |
423 | ||
424 | RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, | |
425 | r_symndx, symtab_hdr, sym_hashes, | |
426 | h, sec, relocation, | |
427 | unresolved_reloc, warned, ignored); | |
428 | ||
429 | name = h->root.root.string; | |
430 | } | |
431 | ||
432 | if (sec != NULL && discarded_section (sec)) | |
433 | RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section, | |
434 | rel, 1, relend, howto, 0, contents); | |
435 | ||
436 | if (bfd_link_relocatable (info)) | |
437 | continue; | |
438 | ||
439 | switch (howto->type) | |
440 | { | |
441 | case R_BPF_INSN_DISP16: | |
442 | case R_BPF_INSN_DISP32: | |
443 | { | |
fc8de8e2 | 444 | /* Make the relocation PC-relative, and change its unit to |
d844f10a DF |
445 | 64-bit words. Note we need *signed* arithmetic |
446 | here. */ | |
447 | relocation = ((bfd_signed_vma) relocation | |
448 | - (sec_addr (input_section) + rel->r_offset)); | |
449 | relocation = (bfd_signed_vma) relocation / 8; | |
fc8de8e2 JM |
450 | |
451 | /* Get the addend from the instruction and apply it. */ | |
452 | addend = bfd_get (howto->bitsize, input_bfd, | |
453 | contents + rel->r_offset | |
454 | + (howto->bitsize == 16 ? 2 : 4)); | |
455 | ||
456 | if ((addend & (((~howto->src_mask) >> 1) & howto->src_mask)) != 0) | |
457 | addend -= (((~howto->src_mask) >> 1) & howto->src_mask) << 1; | |
458 | relocation += addend; | |
459 | ||
460 | /* Write out the relocated value. */ | |
461 | bfd_put (howto->bitsize, input_bfd, relocation, | |
462 | contents + rel->r_offset | |
463 | + (howto->bitsize == 16 ? 2 : 4)); | |
464 | ||
465 | r = bfd_reloc_ok; | |
466 | break; | |
467 | } | |
3ee9565c DF |
468 | case R_BPF_DATA_8: |
469 | case R_BPF_DATA_16: | |
470 | case R_BPF_DATA_32: | |
471 | case R_BPF_DATA_64: | |
472 | { | |
473 | addend = bfd_get (howto->bitsize, input_bfd, where); | |
474 | relocation += addend; | |
475 | bfd_put (howto->bitsize, input_bfd, relocation, where); | |
476 | ||
477 | r = bfd_reloc_ok; | |
478 | break; | |
479 | } | |
480 | case R_BPF_INSN_16: | |
481 | { | |
482 | ||
483 | addend = bfd_get_16 (input_bfd, where + 2); | |
484 | relocation += addend; | |
485 | bfd_put_16 (input_bfd, relocation, where + 2); | |
486 | ||
487 | r = bfd_reloc_ok; | |
488 | break; | |
489 | } | |
12adf805 DF |
490 | case R_BPF_INSN_32: |
491 | { | |
492 | /* Write relocated value */ | |
3ee9565c DF |
493 | |
494 | addend = bfd_get_32 (input_bfd, where + 4); | |
495 | relocation += addend; | |
496 | bfd_put_32 (input_bfd, relocation, where + 4); | |
12adf805 DF |
497 | |
498 | r = bfd_reloc_ok; | |
499 | break; | |
500 | } | |
501 | case R_BPF_INSN_64: | |
502 | { | |
503 | /* | |
504 | LDDW instructions are 128 bits long, with a 64-bit immediate. | |
505 | The lower 32 bits of the immediate are in the same position | |
506 | as the imm32 field of other instructions. | |
507 | The upper 32 bits of the immediate are stored at the end of | |
508 | the instruction. | |
509 | */ | |
3ee9565c DF |
510 | |
511 | ||
512 | /* Get the addend. The upper and lower 32 bits are split. | |
513 | 'where' is the beginning of the 16-byte instruction. */ | |
514 | addend = bfd_get_32 (input_bfd, where + 4); | |
515 | addend |= (bfd_get_32 (input_bfd, where + 12) << 32); | |
516 | ||
517 | relocation += addend; | |
518 | ||
519 | bfd_put_32 (input_bfd, (relocation & 0xFFFFFFFF), where + 4); | |
520 | bfd_put_32 (input_bfd, (relocation >> 32), where + 12); | |
12adf805 DF |
521 | r = bfd_reloc_ok; |
522 | break; | |
523 | } | |
fc8de8e2 | 524 | default: |
3ee9565c | 525 | r = bfd_reloc_notsupported; |
fc8de8e2 JM |
526 | } |
527 | ||
3ee9565c DF |
528 | if (r == bfd_reloc_ok) |
529 | r = bfd_check_overflow (howto->complain_on_overflow, | |
530 | howto->bitsize, | |
531 | howto->rightshift, | |
532 | 64, relocation); | |
533 | ||
fc8de8e2 JM |
534 | if (r != bfd_reloc_ok) |
535 | { | |
536 | const char * msg = NULL; | |
537 | ||
538 | switch (r) | |
539 | { | |
540 | case bfd_reloc_overflow: | |
541 | (*info->callbacks->reloc_overflow) | |
542 | (info, (h ? &h->root : NULL), name, howto->name, | |
543 | (bfd_vma) 0, input_bfd, input_section, rel->r_offset); | |
544 | break; | |
545 | ||
546 | case bfd_reloc_undefined: | |
547 | (*info->callbacks->undefined_symbol) | |
548 | (info, name, input_bfd, input_section, rel->r_offset, TRUE); | |
549 | break; | |
550 | ||
551 | case bfd_reloc_outofrange: | |
552 | msg = _("internal error: out of range error"); | |
553 | break; | |
554 | ||
555 | case bfd_reloc_notsupported: | |
556 | if (sym != NULL) /* Only if it's not an unresolved symbol. */ | |
557 | msg = _("internal error: relocation not supported"); | |
558 | break; | |
559 | ||
560 | case bfd_reloc_dangerous: | |
561 | msg = _("internal error: dangerous relocation"); | |
562 | break; | |
563 | ||
564 | default: | |
565 | msg = _("internal error: unknown error"); | |
566 | break; | |
567 | } | |
568 | ||
569 | if (msg) | |
570 | (*info->callbacks->warning) (info, msg, name, input_bfd, | |
571 | input_section, rel->r_offset); | |
572 | } | |
573 | } | |
574 | ||
575 | return TRUE; | |
576 | } | |
577 | ||
fd0de36e JM |
578 | /* Merge backend specific data from an object file to the output |
579 | object file when linking. */ | |
580 | ||
581 | static bfd_boolean | |
582 | elf64_bpf_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info) | |
583 | { | |
584 | /* Check if we have the same endianness. */ | |
585 | if (! _bfd_generic_verify_endian_match (ibfd, info)) | |
586 | return FALSE; | |
587 | ||
588 | return TRUE; | |
589 | } | |
590 | ||
3ee9565c DF |
591 | /* A generic howto special function for installing BPF relocations. |
592 | This function will be called by the assembler (via bfd_install_relocation). | |
593 | At link time, bpf_elf_relocate_section will resolve the final relocations. | |
594 | ||
595 | BPF instructions are always big endian, and this approach avoids problems in | |
596 | bfd_install_relocation. */ | |
597 | ||
598 | static bfd_reloc_status_type | |
599 | bpf_elf_generic_reloc (bfd * abfd, arelent *reloc_entry, asymbol *symbol, | |
600 | void *data, asection *input_section, | |
601 | bfd *output_bfd, | |
602 | char **error_message ATTRIBUTE_UNUSED) | |
603 | { | |
604 | ||
605 | bfd_signed_vma relocation; | |
606 | bfd_reloc_status_type status; | |
607 | bfd_byte *where; | |
608 | ||
609 | /* Sanity check that the address is in range. */ | |
610 | if (reloc_entry->address > bfd_get_section_limit (abfd, input_section)) | |
611 | return bfd_reloc_outofrange; | |
612 | ||
613 | /* Get the symbol value. */ | |
614 | if (bfd_is_com_section (symbol->section)) | |
615 | relocation = 0; | |
616 | else | |
617 | relocation = symbol->value; | |
618 | ||
619 | if (symbol->flags & BSF_SECTION_SYM) | |
620 | /* Relocation against a section symbol: add in the section base address. */ | |
621 | relocation += BASEADDR (symbol->section); | |
622 | ||
623 | relocation += reloc_entry->addend; | |
624 | ||
625 | where = (bfd_byte *) data + reloc_entry->address; | |
626 | ||
627 | status = bfd_check_overflow (reloc_entry->howto->complain_on_overflow, | |
628 | reloc_entry->howto->bitsize, | |
629 | reloc_entry->howto->rightshift, 64, relocation); | |
630 | ||
631 | if (status != bfd_reloc_ok) | |
632 | return status; | |
633 | ||
634 | /* Now finally install the relocation. */ | |
635 | if (reloc_entry->howto->type == R_BPF_INSN_64) | |
636 | { | |
637 | /* lddw is a 128-bit (!) instruction that allows loading a 64-bit | |
638 | immediate into a register. the immediate is split in half, with the | |
639 | lower 32 bits in the same position as the imm32 field of other | |
640 | instructions, and the upper 32 bits placed at the very end of the | |
641 | instruction. that is, there are 32 unused bits between them. */ | |
642 | ||
643 | bfd_put_32 (output_bfd, (relocation & 0xFFFFFFFF), where + 4); | |
644 | bfd_put_32 (output_bfd, (relocation >> 32), where + 12); | |
645 | } | |
646 | else | |
647 | { | |
648 | /* For other kinds of relocations, the relocated value simply goes | |
649 | BITPOS bits from the start of the entry. This is always a multiple | |
650 | of 8, i.e. whole bytes. */ | |
651 | bfd_put (reloc_entry->howto->bitsize, output_bfd, relocation, | |
652 | where + reloc_entry->howto->bitpos / 8); | |
653 | } | |
654 | ||
655 | reloc_entry->addend = relocation; | |
656 | reloc_entry->address += input_section->output_offset; | |
657 | ||
658 | return bfd_reloc_ok; | |
659 | } | |
660 | ||
661 | ||
fd0de36e JM |
662 | /* The macros below configure the architecture. */ |
663 | ||
664 | #define TARGET_LITTLE_SYM bpf_elf64_le_vec | |
665 | #define TARGET_LITTLE_NAME "elf64-bpfle" | |
666 | ||
667 | #define TARGET_BIG_SYM bpf_elf64_be_vec | |
668 | #define TARGET_BIG_NAME "elf64-bpfbe" | |
669 | ||
670 | #define ELF_ARCH bfd_arch_bpf | |
671 | #define ELF_MACHINE_CODE EM_BPF | |
672 | ||
673 | #define ELF_MAXPAGESIZE 0x100000 | |
674 | ||
675 | #define elf_info_to_howto_rel bpf_info_to_howto | |
676 | #define elf_info_to_howto bpf_info_to_howto | |
677 | ||
678 | #define elf_backend_may_use_rel_p 1 | |
679 | #define elf_backend_may_use_rela_p 0 | |
680 | #define elf_backend_default_use_rela_p 0 | |
fc8de8e2 | 681 | #define elf_backend_relocate_section bpf_elf_relocate_section |
fd0de36e JM |
682 | |
683 | #define elf_backend_can_gc_sections 0 | |
684 | ||
685 | #define elf_symbol_leading_char '_' | |
686 | #define bfd_elf64_bfd_reloc_type_lookup bpf_reloc_type_lookup | |
687 | #define bfd_elf64_bfd_reloc_name_lookup bpf_reloc_name_lookup | |
688 | ||
689 | #define bfd_elf64_bfd_merge_private_bfd_data elf64_bpf_merge_private_bfd_data | |
690 | ||
691 | #include "elf64-target.h" |