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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/sections.h>
15
16static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v)
17{
18 if (v != (u32)v) {
19 pr_err("%s: value %016llx out of range for 32-bit field\n",
20 me->name, (long long)v);
21 return -EINVAL;
22 }
23 *location = v;
24 return 0;
25}
26
27static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v)
28{
29 *(u64 *)location = v;
30 return 0;
31}
32
33static int apply_r_riscv_branch_rela(struct module *me, u32 *location,
34 Elf_Addr v)
35{
36 ptrdiff_t offset = (void *)v - (void *)location;
37 u32 imm12 = (offset & 0x1000) << (31 - 12);
38 u32 imm11 = (offset & 0x800) >> (11 - 7);
39 u32 imm10_5 = (offset & 0x7e0) << (30 - 10);
40 u32 imm4_1 = (offset & 0x1e) << (11 - 4);
41
42 *location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1;
43 return 0;
44}
45
46static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
47 Elf_Addr v)
48{
49 ptrdiff_t offset = (void *)v - (void *)location;
50 u32 imm20 = (offset & 0x100000) << (31 - 20);
51 u32 imm19_12 = (offset & 0xff000);
52 u32 imm11 = (offset & 0x800) << (20 - 11);
53 u32 imm10_1 = (offset & 0x7fe) << (30 - 10);
54
55 *location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1;
56 return 0;
57}
58
59static int apply_r_riscv_rcv_branch_rela(struct module *me, u32 *location,
60 Elf_Addr v)
61{
62 ptrdiff_t offset = (void *)v - (void *)location;
63 u16 imm8 = (offset & 0x100) << (12 - 8);
64 u16 imm7_6 = (offset & 0xc0) >> (6 - 5);
65 u16 imm5 = (offset & 0x20) >> (5 - 2);
66 u16 imm4_3 = (offset & 0x18) << (12 - 5);
67 u16 imm2_1 = (offset & 0x6) << (12 - 10);
68
69 *(u16 *)location = (*(u16 *)location & 0xe383) |
70 imm8 | imm7_6 | imm5 | imm4_3 | imm2_1;
71 return 0;
72}
73
74static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location,
75 Elf_Addr v)
76{
77 ptrdiff_t offset = (void *)v - (void *)location;
78 u16 imm11 = (offset & 0x800) << (12 - 11);
79 u16 imm10 = (offset & 0x400) >> (10 - 8);
80 u16 imm9_8 = (offset & 0x300) << (12 - 11);
81 u16 imm7 = (offset & 0x80) >> (7 - 6);
82 u16 imm6 = (offset & 0x40) << (12 - 11);
83 u16 imm5 = (offset & 0x20) >> (5 - 2);
84 u16 imm4 = (offset & 0x10) << (12 - 5);
85 u16 imm3_1 = (offset & 0xe) << (12 - 10);
86
87 *(u16 *)location = (*(u16 *)location & 0xe003) |
88 imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1;
89 return 0;
90}
91
92static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location,
93 Elf_Addr v)
94{
95 ptrdiff_t offset = (void *)v - (void *)location;
96 s32 hi20;
97
98 if (offset != (s32)offset) {
99 pr_err(
100 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
101 me->name, (long long)v, location);
102 return -EINVAL;
103 }
104
105 hi20 = (offset + 0x800) & 0xfffff000;
106 *location = (*location & 0xfff) | hi20;
107 return 0;
108}
109
110static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location,
111 Elf_Addr v)
112{
113 /*
114 * v is the lo12 value to fill. It is calculated before calling this
115 * handler.
116 */
117 *location = (*location & 0xfffff) | ((v & 0xfff) << 20);
118 return 0;
119}
120
121static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
122 Elf_Addr v)
123{
124 /*
125 * v is the lo12 value to fill. It is calculated before calling this
126 * handler.
127 */
128 u32 imm11_5 = (v & 0xfe0) << (31 - 11);
129 u32 imm4_0 = (v & 0x1f) << (11 - 4);
130
131 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
132 return 0;
133}
134
135static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,
136 Elf_Addr v)
137{
138 s32 hi20;
139
140 if (IS_ENABLED(CONFIG_CMODEL_MEDLOW)) {
141 pr_err(
142 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
143 me->name, (long long)v, location);
144 return -EINVAL;
145 }
146
147 hi20 = ((s32)v + 0x800) & 0xfffff000;
148 *location = (*location & 0xfff) | hi20;
149 return 0;
150}
151
152static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,
153 Elf_Addr v)
154{
155 /* Skip medlow checking because of filtering by HI20 already */
156 s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
157 s32 lo12 = ((s32)v - hi20);
158 *location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20);
159 return 0;
160}
161
162static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,
163 Elf_Addr v)
164{
165 /* Skip medlow checking because of filtering by HI20 already */
166 s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
167 s32 lo12 = ((s32)v - hi20);
168 u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11);
169 u32 imm4_0 = (lo12 & 0x1f) << (11 - 4);
170 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
171 return 0;
172}
173
174static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,
175 Elf_Addr v)
176{
177 ptrdiff_t offset = (void *)v - (void *)location;
178 s32 hi20;
179
180 /* Always emit the got entry */
181 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
182 offset = module_emit_got_entry(me, v);
183 offset = (void *)offset - (void *)location;
184 } else {
185 pr_err(
186 "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n",
187 me->name, (long long)v, location);
188 return -EINVAL;
189 }
190
191 hi20 = (offset + 0x800) & 0xfffff000;
192 *location = (*location & 0xfff) | hi20;
193 return 0;
194}
195
196static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
197 Elf_Addr v)
198{
199 ptrdiff_t offset = (void *)v - (void *)location;
200 s32 fill_v = offset;
201 u32 hi20, lo12;
202
203 if (offset != fill_v) {
204 /* Only emit the plt entry if offset over 32-bit range */
205 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
206 offset = module_emit_plt_entry(me, v);
207 offset = (void *)offset - (void *)location;
208 } else {
209 pr_err(
210 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
211 me->name, (long long)v, location);
212 return -EINVAL;
213 }
214 }
215
216 hi20 = (offset + 0x800) & 0xfffff000;
217 lo12 = (offset - hi20) & 0xfff;
218 *location = (*location & 0xfff) | hi20;
219 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
220 return 0;
221}
222
223static int apply_r_riscv_call_rela(struct module *me, u32 *location,
224 Elf_Addr v)
225{
226 ptrdiff_t offset = (void *)v - (void *)location;
227 s32 fill_v = offset;
228 u32 hi20, lo12;
229
230 if (offset != fill_v) {
231 pr_err(
232 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
233 me->name, (long long)v, location);
234 return -EINVAL;
235 }
236
237 hi20 = (offset + 0x800) & 0xfffff000;
238 lo12 = (offset - hi20) & 0xfff;
239 *location = (*location & 0xfff) | hi20;
240 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
241 return 0;
242}
243
244static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
245 Elf_Addr v)
246{
247 return 0;
248}
249
250static int apply_r_riscv_align_rela(struct module *me, u32 *location,
251 Elf_Addr v)
252{
253 pr_err(
254 "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n",
255 me->name, location);
256 return -EINVAL;
257}
258
259static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
260 Elf_Addr v)
261{
262 *(u32 *)location += (u32)v;
263 return 0;
264}
265
266static int apply_r_riscv_add64_rela(struct module *me, u32 *location,
267 Elf_Addr v)
268{
269 *(u64 *)location += (u64)v;
270 return 0;
271}
272
273static int apply_r_riscv_sub32_rela(struct module *me, u32 *location,
274 Elf_Addr v)
275{
276 *(u32 *)location -= (u32)v;
277 return 0;
278}
279
280static int apply_r_riscv_sub64_rela(struct module *me, u32 *location,
281 Elf_Addr v)
282{
283 *(u64 *)location -= (u64)v;
284 return 0;
285}
286
287static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
288 Elf_Addr v) = {
289 [R_RISCV_32] = apply_r_riscv_32_rela,
290 [R_RISCV_64] = apply_r_riscv_64_rela,
291 [R_RISCV_BRANCH] = apply_r_riscv_branch_rela,
292 [R_RISCV_JAL] = apply_r_riscv_jal_rela,
293 [R_RISCV_RVC_BRANCH] = apply_r_riscv_rcv_branch_rela,
294 [R_RISCV_RVC_JUMP] = apply_r_riscv_rvc_jump_rela,
295 [R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela,
296 [R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela,
297 [R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela,
298 [R_RISCV_HI20] = apply_r_riscv_hi20_rela,
299 [R_RISCV_LO12_I] = apply_r_riscv_lo12_i_rela,
300 [R_RISCV_LO12_S] = apply_r_riscv_lo12_s_rela,
301 [R_RISCV_GOT_HI20] = apply_r_riscv_got_hi20_rela,
302 [R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela,
303 [R_RISCV_CALL] = apply_r_riscv_call_rela,
304 [R_RISCV_RELAX] = apply_r_riscv_relax_rela,
305 [R_RISCV_ALIGN] = apply_r_riscv_align_rela,
306 [R_RISCV_ADD32] = apply_r_riscv_add32_rela,
307 [R_RISCV_ADD64] = apply_r_riscv_add64_rela,
308 [R_RISCV_SUB32] = apply_r_riscv_sub32_rela,
309 [R_RISCV_SUB64] = apply_r_riscv_sub64_rela,
310};
311
312int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
313 unsigned int symindex, unsigned int relsec,
314 struct module *me)
315{
316 Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
317 int (*handler)(struct module *me, u32 *location, Elf_Addr v);
318 Elf_Sym *sym;
319 u32 *location;
320 unsigned int i, type;
321 Elf_Addr v;
322 int res;
323
324 pr_debug("Applying relocate section %u to %u\n", relsec,
325 sechdrs[relsec].sh_info);
326
327 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
328 /* This is where to make the change */
329 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
330 + rel[i].r_offset;
331 /* This is the symbol it is referring to */
332 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
333 + ELF_RISCV_R_SYM(rel[i].r_info);
334 if (IS_ERR_VALUE(sym->st_value)) {
335 /* Ignore unresolved weak symbol */
336 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
337 continue;
338 pr_warn("%s: Unknown symbol %s\n",
339 me->name, strtab + sym->st_name);
340 return -ENOENT;
341 }
342
343 type = ELF_RISCV_R_TYPE(rel[i].r_info);
344
345 if (type < ARRAY_SIZE(reloc_handlers_rela))
346 handler = reloc_handlers_rela[type];
347 else
348 handler = NULL;
349
350 if (!handler) {
351 pr_err("%s: Unknown relocation type %u\n",
352 me->name, type);
353 return -EINVAL;
354 }
355
356 v = sym->st_value + rel[i].r_addend;
357
358 if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) {
359 unsigned int j;
360
361 for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) {
362 unsigned long hi20_loc =
363 sechdrs[sechdrs[relsec].sh_info].sh_addr
364 + rel[j].r_offset;
365 u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info);
366
367 /* Find the corresponding HI20 relocation entry */
368 if (hi20_loc == sym->st_value
369 && (hi20_type == R_RISCV_PCREL_HI20
370 || hi20_type == R_RISCV_GOT_HI20)) {
371 s32 hi20, lo12;
372 Elf_Sym *hi20_sym =
373 (Elf_Sym *)sechdrs[symindex].sh_addr
374 + ELF_RISCV_R_SYM(rel[j].r_info);
375 unsigned long hi20_sym_val =
376 hi20_sym->st_value
377 + rel[j].r_addend;
378
379 /* Calculate lo12 */
380 size_t offset = hi20_sym_val - hi20_loc;
381 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)
382 && hi20_type == R_RISCV_GOT_HI20) {
383 offset = module_emit_got_entry(
384 me, hi20_sym_val);
385 offset = offset - hi20_loc;
386 }
387 hi20 = (offset + 0x800) & 0xfffff000;
388 lo12 = offset - hi20;
389 v = lo12;
390
391 break;
392 }
393 }
394 if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
395 pr_err(
396 "%s: Can not find HI20 relocation information\n",
397 me->name);
398 return -EINVAL;
399 }
400 }
401
402 res = handler(me, location, v);
403 if (res)
404 return res;
405 }
406
407 return 0;
408}
409
410#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
411#define VMALLOC_MODULE_START \
412 max(PFN_ALIGN((unsigned long)&_end - SZ_2G), VMALLOC_START)
413void *module_alloc(unsigned long size)
414{
415 return __vmalloc_node_range(size, 1, VMALLOC_MODULE_START,
416 VMALLOC_END, GFP_KERNEL,
417 PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
418 __builtin_return_address(0));
419}
420#endif