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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
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}