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1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * Copyright (C) 2017 Zihao Yu
13 */
14
15#include <linux/elf.h>
16#include <linux/err.h>
17#include <linux/errno.h>
18#include <linux/moduleloader.h>
19
20static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v)
21{
22 *(u64 *)location = v;
23 return 0;
24}
25
26static int apply_r_riscv_branch_rela(struct module *me, u32 *location,
27 Elf_Addr v)
28{
29 s64 offset = (void *)v - (void *)location;
30 u32 imm12 = (offset & 0x1000) << (31 - 12);
31 u32 imm11 = (offset & 0x800) >> (11 - 7);
32 u32 imm10_5 = (offset & 0x7e0) << (30 - 10);
33 u32 imm4_1 = (offset & 0x1e) << (11 - 4);
34
35 *location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1;
36 return 0;
37}
38
39static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
40 Elf_Addr v)
41{
42 s64 offset = (void *)v - (void *)location;
43 u32 imm20 = (offset & 0x100000) << (31 - 20);
44 u32 imm19_12 = (offset & 0xff000);
45 u32 imm11 = (offset & 0x800) << (20 - 11);
46 u32 imm10_1 = (offset & 0x7fe) << (30 - 10);
47
48 *location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1;
49 return 0;
50}
51
52static int apply_r_riscv_rcv_branch_rela(struct module *me, u32 *location,
53 Elf_Addr v)
54{
55 s64 offset = (void *)v - (void *)location;
56 u16 imm8 = (offset & 0x100) << (12 - 8);
57 u16 imm7_6 = (offset & 0xc0) >> (6 - 5);
58 u16 imm5 = (offset & 0x20) >> (5 - 2);
59 u16 imm4_3 = (offset & 0x18) << (12 - 5);
60 u16 imm2_1 = (offset & 0x6) << (12 - 10);
61
62 *(u16 *)location = (*(u16 *)location & 0xe383) |
63 imm8 | imm7_6 | imm5 | imm4_3 | imm2_1;
64 return 0;
65}
66
67static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location,
68 Elf_Addr v)
69{
70 s64 offset = (void *)v - (void *)location;
71 u16 imm11 = (offset & 0x800) << (12 - 11);
72 u16 imm10 = (offset & 0x400) >> (10 - 8);
73 u16 imm9_8 = (offset & 0x300) << (12 - 11);
74 u16 imm7 = (offset & 0x80) >> (7 - 6);
75 u16 imm6 = (offset & 0x40) << (12 - 11);
76 u16 imm5 = (offset & 0x20) >> (5 - 2);
77 u16 imm4 = (offset & 0x10) << (12 - 5);
78 u16 imm3_1 = (offset & 0xe) << (12 - 10);
79
80 *(u16 *)location = (*(u16 *)location & 0xe003) |
81 imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1;
82 return 0;
83}
84
85static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location,
86 Elf_Addr v)
87{
88 s64 offset = (void *)v - (void *)location;
89 s32 hi20;
90
91 if (offset != (s32)offset) {
92 pr_err(
93 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
94 me->name, v, location);
95 return -EINVAL;
96 }
97
98 hi20 = (offset + 0x800) & 0xfffff000;
99 *location = (*location & 0xfff) | hi20;
100 return 0;
101}
102
103static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location,
104 Elf_Addr v)
105{
106 /*
107 * v is the lo12 value to fill. It is calculated before calling this
108 * handler.
109 */
110 *location = (*location & 0xfffff) | ((v & 0xfff) << 20);
111 return 0;
112}
113
114static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
115 Elf_Addr v)
116{
117 /*
118 * v is the lo12 value to fill. It is calculated before calling this
119 * handler.
120 */
121 u32 imm11_5 = (v & 0xfe0) << (31 - 11);
122 u32 imm4_0 = (v & 0x1f) << (11 - 4);
123
124 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
125 return 0;
126}
127
128static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,
129 Elf_Addr v)
130{
131 s32 hi20;
132
133 if (IS_ENABLED(CMODEL_MEDLOW)) {
134 pr_err(
135 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
136 me->name, v, location);
137 return -EINVAL;
138 }
139
140 hi20 = ((s32)v + 0x800) & 0xfffff000;
141 *location = (*location & 0xfff) | hi20;
142 return 0;
143}
144
145static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,
146 Elf_Addr v)
147{
148 /* Skip medlow checking because of filtering by HI20 already */
149 s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
150 s32 lo12 = ((s32)v - hi20);
151 *location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20);
152 return 0;
153}
154
155static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,
156 Elf_Addr v)
157{
158 /* Skip medlow checking because of filtering by HI20 already */
159 s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
160 s32 lo12 = ((s32)v - hi20);
161 u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11);
162 u32 imm4_0 = (lo12 & 0x1f) << (11 - 4);
163 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
164 return 0;
165}
166
167static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,
168 Elf_Addr v)
169{
170 s64 offset = (void *)v - (void *)location;
171 s32 hi20;
172
173 /* Always emit the got entry */
174 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
175 offset = module_emit_got_entry(me, v);
176 offset = (void *)offset - (void *)location;
177 } else {
178 pr_err(
179 "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n",
180 me->name, v, location);
181 return -EINVAL;
182 }
183
184 hi20 = (offset + 0x800) & 0xfffff000;
185 *location = (*location & 0xfff) | hi20;
186 return 0;
187}
188
189static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
190 Elf_Addr v)
191{
192 s64 offset = (void *)v - (void *)location;
193 s32 fill_v = offset;
194 u32 hi20, lo12;
195
196 if (offset != fill_v) {
197 /* Only emit the plt entry if offset over 32-bit range */
198 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
199 offset = module_emit_plt_entry(me, v);
200 offset = (void *)offset - (void *)location;
201 } else {
202 pr_err(
203 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
204 me->name, v, location);
205 return -EINVAL;
206 }
207 }
208
209 hi20 = (offset + 0x800) & 0xfffff000;
210 lo12 = (offset - hi20) & 0xfff;
211 *location = (*location & 0xfff) | hi20;
212 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
213 return 0;
214}
215
216static int apply_r_riscv_call_rela(struct module *me, u32 *location,
217 Elf_Addr v)
218{
219 s64 offset = (void *)v - (void *)location;
220 s32 fill_v = offset;
221 u32 hi20, lo12;
222
223 if (offset != fill_v) {
224 pr_err(
225 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
226 me->name, v, location);
227 return -EINVAL;
228 }
229
230 hi20 = (offset + 0x800) & 0xfffff000;
231 lo12 = (offset - hi20) & 0xfff;
232 *location = (*location & 0xfff) | hi20;
233 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
234 return 0;
235}
236
237static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
238 Elf_Addr v)
239{
240 return 0;
241}
242
243static int apply_r_riscv_align_rela(struct module *me, u32 *location,
244 Elf_Addr v)
245{
246 pr_err(
247 "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n",
248 me->name, location);
249 return -EINVAL;
250}
251
252static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
253 Elf_Addr v)
254{
255 *(u32 *)location += (*(u32 *)v);
256 return 0;
257}
258
259static int apply_r_riscv_sub32_rela(struct module *me, u32 *location,
260 Elf_Addr v)
261{
262 *(u32 *)location -= (*(u32 *)v);
263 return 0;
264}
265
266static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
267 Elf_Addr v) = {
268 [R_RISCV_64] = apply_r_riscv_64_rela,
269 [R_RISCV_BRANCH] = apply_r_riscv_branch_rela,
270 [R_RISCV_JAL] = apply_r_riscv_jal_rela,
271 [R_RISCV_RVC_BRANCH] = apply_r_riscv_rcv_branch_rela,
272 [R_RISCV_RVC_JUMP] = apply_r_riscv_rvc_jump_rela,
273 [R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela,
274 [R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela,
275 [R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela,
276 [R_RISCV_HI20] = apply_r_riscv_hi20_rela,
277 [R_RISCV_LO12_I] = apply_r_riscv_lo12_i_rela,
278 [R_RISCV_LO12_S] = apply_r_riscv_lo12_s_rela,
279 [R_RISCV_GOT_HI20] = apply_r_riscv_got_hi20_rela,
280 [R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela,
281 [R_RISCV_CALL] = apply_r_riscv_call_rela,
282 [R_RISCV_RELAX] = apply_r_riscv_relax_rela,
283 [R_RISCV_ALIGN] = apply_r_riscv_align_rela,
284 [R_RISCV_ADD32] = apply_r_riscv_add32_rela,
285 [R_RISCV_SUB32] = apply_r_riscv_sub32_rela,
286};
287
288int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
289 unsigned int symindex, unsigned int relsec,
290 struct module *me)
291{
292 Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
293 int (*handler)(struct module *me, u32 *location, Elf_Addr v);
294 Elf_Sym *sym;
295 u32 *location;
296 unsigned int i, type;
297 Elf_Addr v;
298 int res;
299
300 pr_debug("Applying relocate section %u to %u\n", relsec,
301 sechdrs[relsec].sh_info);
302
303 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
304 /* This is where to make the change */
305 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
306 + rel[i].r_offset;
307 /* This is the symbol it is referring to */
308 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
309 + ELF_RISCV_R_SYM(rel[i].r_info);
310 if (IS_ERR_VALUE(sym->st_value)) {
311 /* Ignore unresolved weak symbol */
312 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
313 continue;
314 pr_warning("%s: Unknown symbol %s\n",
315 me->name, strtab + sym->st_name);
316 return -ENOENT;
317 }
318
319 type = ELF_RISCV_R_TYPE(rel[i].r_info);
320
321 if (type < ARRAY_SIZE(reloc_handlers_rela))
322 handler = reloc_handlers_rela[type];
323 else
324 handler = NULL;
325
326 if (!handler) {
327 pr_err("%s: Unknown relocation type %u\n",
328 me->name, type);
329 return -EINVAL;
330 }
331
332 v = sym->st_value + rel[i].r_addend;
333
334 if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) {
335 unsigned int j;
336
337 for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) {
338 u64 hi20_loc =
339 sechdrs[sechdrs[relsec].sh_info].sh_addr
340 + rel[j].r_offset;
341 u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info);
342
343 /* Find the corresponding HI20 relocation entry */
344 if (hi20_loc == sym->st_value
345 && (hi20_type == R_RISCV_PCREL_HI20
346 || hi20_type == R_RISCV_GOT_HI20)) {
347 s32 hi20, lo12;
348 Elf_Sym *hi20_sym =
349 (Elf_Sym *)sechdrs[symindex].sh_addr
350 + ELF_RISCV_R_SYM(rel[j].r_info);
351 u64 hi20_sym_val =
352 hi20_sym->st_value
353 + rel[j].r_addend;
354
355 /* Calculate lo12 */
356 u64 offset = hi20_sym_val - hi20_loc;
357 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)
358 && hi20_type == R_RISCV_GOT_HI20) {
359 offset = module_emit_got_entry(
360 me, hi20_sym_val);
361 offset = offset - hi20_loc;
362 }
363 hi20 = (offset + 0x800) & 0xfffff000;
364 lo12 = offset - hi20;
365 v = lo12;
366
367 break;
368 }
369 }
370 if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
371 pr_err(
372 "%s: Can not find HI20 relocation information\n",
373 me->name);
374 return -EINVAL;
375 }
376 }
377
378 res = handler(me, location, v);
379 if (res)
380 return res;
381 }
382
383 return 0;
384}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright (C) 2017 Zihao Yu
5 */
6
7#include <linux/elf.h>
8#include <linux/err.h>
9#include <linux/errno.h>
10#include <linux/moduleloader.h>
11#include <linux/vmalloc.h>
12#include <linux/sizes.h>
13#include <linux/pgtable.h>
14#include <asm/alternative.h>
15#include <asm/sections.h>
16
17/*
18 * The auipc+jalr instruction pair can reach any PC-relative offset
19 * in the range [-2^31 - 2^11, 2^31 - 2^11)
20 */
21static bool riscv_insn_valid_32bit_offset(ptrdiff_t val)
22{
23#ifdef CONFIG_32BIT
24 return true;
25#else
26 return (-(1L << 31) - (1L << 11)) <= val && val < ((1L << 31) - (1L << 11));
27#endif
28}
29
30static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v)
31{
32 if (v != (u32)v) {
33 pr_err("%s: value %016llx out of range for 32-bit field\n",
34 me->name, (long long)v);
35 return -EINVAL;
36 }
37 *location = v;
38 return 0;
39}
40
41static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v)
42{
43 *(u64 *)location = v;
44 return 0;
45}
46
47static int apply_r_riscv_branch_rela(struct module *me, u32 *location,
48 Elf_Addr v)
49{
50 ptrdiff_t offset = (void *)v - (void *)location;
51 u32 imm12 = (offset & 0x1000) << (31 - 12);
52 u32 imm11 = (offset & 0x800) >> (11 - 7);
53 u32 imm10_5 = (offset & 0x7e0) << (30 - 10);
54 u32 imm4_1 = (offset & 0x1e) << (11 - 4);
55
56 *location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1;
57 return 0;
58}
59
60static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
61 Elf_Addr v)
62{
63 ptrdiff_t offset = (void *)v - (void *)location;
64 u32 imm20 = (offset & 0x100000) << (31 - 20);
65 u32 imm19_12 = (offset & 0xff000);
66 u32 imm11 = (offset & 0x800) << (20 - 11);
67 u32 imm10_1 = (offset & 0x7fe) << (30 - 10);
68
69 *location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1;
70 return 0;
71}
72
73static int apply_r_riscv_rvc_branch_rela(struct module *me, u32 *location,
74 Elf_Addr v)
75{
76 ptrdiff_t offset = (void *)v - (void *)location;
77 u16 imm8 = (offset & 0x100) << (12 - 8);
78 u16 imm7_6 = (offset & 0xc0) >> (6 - 5);
79 u16 imm5 = (offset & 0x20) >> (5 - 2);
80 u16 imm4_3 = (offset & 0x18) << (12 - 5);
81 u16 imm2_1 = (offset & 0x6) << (12 - 10);
82
83 *(u16 *)location = (*(u16 *)location & 0xe383) |
84 imm8 | imm7_6 | imm5 | imm4_3 | imm2_1;
85 return 0;
86}
87
88static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location,
89 Elf_Addr v)
90{
91 ptrdiff_t offset = (void *)v - (void *)location;
92 u16 imm11 = (offset & 0x800) << (12 - 11);
93 u16 imm10 = (offset & 0x400) >> (10 - 8);
94 u16 imm9_8 = (offset & 0x300) << (12 - 11);
95 u16 imm7 = (offset & 0x80) >> (7 - 6);
96 u16 imm6 = (offset & 0x40) << (12 - 11);
97 u16 imm5 = (offset & 0x20) >> (5 - 2);
98 u16 imm4 = (offset & 0x10) << (12 - 5);
99 u16 imm3_1 = (offset & 0xe) << (12 - 10);
100
101 *(u16 *)location = (*(u16 *)location & 0xe003) |
102 imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1;
103 return 0;
104}
105
106static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location,
107 Elf_Addr v)
108{
109 ptrdiff_t offset = (void *)v - (void *)location;
110 s32 hi20;
111
112 if (!riscv_insn_valid_32bit_offset(offset)) {
113 pr_err(
114 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
115 me->name, (long long)v, location);
116 return -EINVAL;
117 }
118
119 hi20 = (offset + 0x800) & 0xfffff000;
120 *location = (*location & 0xfff) | hi20;
121 return 0;
122}
123
124static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location,
125 Elf_Addr v)
126{
127 /*
128 * v is the lo12 value to fill. It is calculated before calling this
129 * handler.
130 */
131 *location = (*location & 0xfffff) | ((v & 0xfff) << 20);
132 return 0;
133}
134
135static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
136 Elf_Addr v)
137{
138 /*
139 * v is the lo12 value to fill. It is calculated before calling this
140 * handler.
141 */
142 u32 imm11_5 = (v & 0xfe0) << (31 - 11);
143 u32 imm4_0 = (v & 0x1f) << (11 - 4);
144
145 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
146 return 0;
147}
148
149static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,
150 Elf_Addr v)
151{
152 s32 hi20;
153
154 if (IS_ENABLED(CONFIG_CMODEL_MEDLOW)) {
155 pr_err(
156 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
157 me->name, (long long)v, location);
158 return -EINVAL;
159 }
160
161 hi20 = ((s32)v + 0x800) & 0xfffff000;
162 *location = (*location & 0xfff) | hi20;
163 return 0;
164}
165
166static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,
167 Elf_Addr v)
168{
169 /* Skip medlow checking because of filtering by HI20 already */
170 s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
171 s32 lo12 = ((s32)v - hi20);
172 *location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20);
173 return 0;
174}
175
176static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,
177 Elf_Addr v)
178{
179 /* Skip medlow checking because of filtering by HI20 already */
180 s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
181 s32 lo12 = ((s32)v - hi20);
182 u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11);
183 u32 imm4_0 = (lo12 & 0x1f) << (11 - 4);
184 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
185 return 0;
186}
187
188static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,
189 Elf_Addr v)
190{
191 ptrdiff_t offset = (void *)v - (void *)location;
192 s32 hi20;
193
194 /* Always emit the got entry */
195 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
196 offset = module_emit_got_entry(me, v);
197 offset = (void *)offset - (void *)location;
198 } else {
199 pr_err(
200 "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n",
201 me->name, (long long)v, location);
202 return -EINVAL;
203 }
204
205 hi20 = (offset + 0x800) & 0xfffff000;
206 *location = (*location & 0xfff) | hi20;
207 return 0;
208}
209
210static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
211 Elf_Addr v)
212{
213 ptrdiff_t offset = (void *)v - (void *)location;
214 u32 hi20, lo12;
215
216 if (!riscv_insn_valid_32bit_offset(offset)) {
217 /* Only emit the plt entry if offset over 32-bit range */
218 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
219 offset = module_emit_plt_entry(me, v);
220 offset = (void *)offset - (void *)location;
221 } else {
222 pr_err(
223 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
224 me->name, (long long)v, location);
225 return -EINVAL;
226 }
227 }
228
229 hi20 = (offset + 0x800) & 0xfffff000;
230 lo12 = (offset - hi20) & 0xfff;
231 *location = (*location & 0xfff) | hi20;
232 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
233 return 0;
234}
235
236static int apply_r_riscv_call_rela(struct module *me, u32 *location,
237 Elf_Addr v)
238{
239 ptrdiff_t offset = (void *)v - (void *)location;
240 u32 hi20, lo12;
241
242 if (!riscv_insn_valid_32bit_offset(offset)) {
243 pr_err(
244 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
245 me->name, (long long)v, location);
246 return -EINVAL;
247 }
248
249 hi20 = (offset + 0x800) & 0xfffff000;
250 lo12 = (offset - hi20) & 0xfff;
251 *location = (*location & 0xfff) | hi20;
252 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
253 return 0;
254}
255
256static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
257 Elf_Addr v)
258{
259 return 0;
260}
261
262static int apply_r_riscv_align_rela(struct module *me, u32 *location,
263 Elf_Addr v)
264{
265 pr_err(
266 "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n",
267 me->name, location);
268 return -EINVAL;
269}
270
271static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
272 Elf_Addr v)
273{
274 *(u32 *)location += (u32)v;
275 return 0;
276}
277
278static int apply_r_riscv_add64_rela(struct module *me, u32 *location,
279 Elf_Addr v)
280{
281 *(u64 *)location += (u64)v;
282 return 0;
283}
284
285static int apply_r_riscv_sub32_rela(struct module *me, u32 *location,
286 Elf_Addr v)
287{
288 *(u32 *)location -= (u32)v;
289 return 0;
290}
291
292static int apply_r_riscv_sub64_rela(struct module *me, u32 *location,
293 Elf_Addr v)
294{
295 *(u64 *)location -= (u64)v;
296 return 0;
297}
298
299static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
300 Elf_Addr v) = {
301 [R_RISCV_32] = apply_r_riscv_32_rela,
302 [R_RISCV_64] = apply_r_riscv_64_rela,
303 [R_RISCV_BRANCH] = apply_r_riscv_branch_rela,
304 [R_RISCV_JAL] = apply_r_riscv_jal_rela,
305 [R_RISCV_RVC_BRANCH] = apply_r_riscv_rvc_branch_rela,
306 [R_RISCV_RVC_JUMP] = apply_r_riscv_rvc_jump_rela,
307 [R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela,
308 [R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela,
309 [R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela,
310 [R_RISCV_HI20] = apply_r_riscv_hi20_rela,
311 [R_RISCV_LO12_I] = apply_r_riscv_lo12_i_rela,
312 [R_RISCV_LO12_S] = apply_r_riscv_lo12_s_rela,
313 [R_RISCV_GOT_HI20] = apply_r_riscv_got_hi20_rela,
314 [R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela,
315 [R_RISCV_CALL] = apply_r_riscv_call_rela,
316 [R_RISCV_RELAX] = apply_r_riscv_relax_rela,
317 [R_RISCV_ALIGN] = apply_r_riscv_align_rela,
318 [R_RISCV_ADD32] = apply_r_riscv_add32_rela,
319 [R_RISCV_ADD64] = apply_r_riscv_add64_rela,
320 [R_RISCV_SUB32] = apply_r_riscv_sub32_rela,
321 [R_RISCV_SUB64] = apply_r_riscv_sub64_rela,
322};
323
324int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
325 unsigned int symindex, unsigned int relsec,
326 struct module *me)
327{
328 Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
329 int (*handler)(struct module *me, u32 *location, Elf_Addr v);
330 Elf_Sym *sym;
331 u32 *location;
332 unsigned int i, type;
333 Elf_Addr v;
334 int res;
335
336 pr_debug("Applying relocate section %u to %u\n", relsec,
337 sechdrs[relsec].sh_info);
338
339 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
340 /* This is where to make the change */
341 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
342 + rel[i].r_offset;
343 /* This is the symbol it is referring to */
344 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
345 + ELF_RISCV_R_SYM(rel[i].r_info);
346 if (IS_ERR_VALUE(sym->st_value)) {
347 /* Ignore unresolved weak symbol */
348 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
349 continue;
350 pr_warn("%s: Unknown symbol %s\n",
351 me->name, strtab + sym->st_name);
352 return -ENOENT;
353 }
354
355 type = ELF_RISCV_R_TYPE(rel[i].r_info);
356
357 if (type < ARRAY_SIZE(reloc_handlers_rela))
358 handler = reloc_handlers_rela[type];
359 else
360 handler = NULL;
361
362 if (!handler) {
363 pr_err("%s: Unknown relocation type %u\n",
364 me->name, type);
365 return -EINVAL;
366 }
367
368 v = sym->st_value + rel[i].r_addend;
369
370 if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) {
371 unsigned int j;
372
373 for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) {
374 unsigned long hi20_loc =
375 sechdrs[sechdrs[relsec].sh_info].sh_addr
376 + rel[j].r_offset;
377 u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info);
378
379 /* Find the corresponding HI20 relocation entry */
380 if (hi20_loc == sym->st_value
381 && (hi20_type == R_RISCV_PCREL_HI20
382 || hi20_type == R_RISCV_GOT_HI20)) {
383 s32 hi20, lo12;
384 Elf_Sym *hi20_sym =
385 (Elf_Sym *)sechdrs[symindex].sh_addr
386 + ELF_RISCV_R_SYM(rel[j].r_info);
387 unsigned long hi20_sym_val =
388 hi20_sym->st_value
389 + rel[j].r_addend;
390
391 /* Calculate lo12 */
392 size_t offset = hi20_sym_val - hi20_loc;
393 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)
394 && hi20_type == R_RISCV_GOT_HI20) {
395 offset = module_emit_got_entry(
396 me, hi20_sym_val);
397 offset = offset - hi20_loc;
398 }
399 hi20 = (offset + 0x800) & 0xfffff000;
400 lo12 = offset - hi20;
401 v = lo12;
402
403 break;
404 }
405 }
406 if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
407 pr_err(
408 "%s: Can not find HI20 relocation information\n",
409 me->name);
410 return -EINVAL;
411 }
412 }
413
414 res = handler(me, location, v);
415 if (res)
416 return res;
417 }
418
419 return 0;
420}
421
422#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
423void *module_alloc(unsigned long size)
424{
425 return __vmalloc_node_range(size, 1, MODULES_VADDR,
426 MODULES_END, GFP_KERNEL,
427 PAGE_KERNEL, 0, NUMA_NO_NODE,
428 __builtin_return_address(0));
429}
430#endif
431
432static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
433 const Elf_Shdr *sechdrs,
434 const char *name)
435{
436 const Elf_Shdr *s, *se;
437 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
438
439 for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) {
440 if (strcmp(name, secstrs + s->sh_name) == 0)
441 return s;
442 }
443
444 return NULL;
445}
446
447int module_finalize(const Elf_Ehdr *hdr,
448 const Elf_Shdr *sechdrs,
449 struct module *me)
450{
451 const Elf_Shdr *s;
452
453 s = find_section(hdr, sechdrs, ".alternative");
454 if (s)
455 apply_module_alternatives((void *)s->sh_addr, s->sh_size);
456
457 return 0;
458}