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.
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.
12 * Copyright (C) 2017 Zihao Yu
15 #include <linux/elf.h>
16 #include <linux/err.h>
17 #include <linux/errno.h>
18 #include <linux/moduleloader.h>
20 static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v)
26 static int apply_r_riscv_branch_rela(struct module *me, u32 *location,
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);
35 *location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1;
39 static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
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);
48 *location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1;
52 static int apply_r_riscv_rcv_branch_rela(struct module *me, u32 *location,
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);
62 *(u16 *)location = (*(u16 *)location & 0xe383) |
63 imm8 | imm7_6 | imm5 | imm4_3 | imm2_1;
67 static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location,
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);
80 *(u16 *)location = (*(u16 *)location & 0xe003) |
81 imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1;
85 static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location,
88 s64 offset = (void *)v - (void *)location;
91 if (offset != (s32)offset) {
93 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
94 me->name, v, location);
98 hi20 = (offset + 0x800) & 0xfffff000;
99 *location = (*location & 0xfff) | hi20;
103 static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location,
107 * v is the lo12 value to fill. It is calculated before calling this
110 *location = (*location & 0xfffff) | ((v & 0xfff) << 20);
114 static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
118 * v is the lo12 value to fill. It is calculated before calling this
121 u32 imm11_5 = (v & 0xfe0) << (31 - 11);
122 u32 imm4_0 = (v & 0x1f) << (11 - 4);
124 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
128 static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,
133 if (IS_ENABLED(CMODEL_MEDLOW)) {
135 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
136 me->name, v, location);
140 hi20 = ((s32)v + 0x800) & 0xfffff000;
141 *location = (*location & 0xfff) | hi20;
145 static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,
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);
155 static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,
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;
167 static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,
170 s64 offset = (void *)v - (void *)location;
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;
179 "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n",
180 me->name, v, location);
184 hi20 = (offset + 0x800) & 0xfffff000;
185 *location = (*location & 0xfff) | hi20;
189 static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
192 s64 offset = (void *)v - (void *)location;
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;
203 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
204 me->name, v, location);
209 hi20 = (offset + 0x800) & 0xfffff000;
210 lo12 = (offset - hi20) & 0xfff;
211 *location = (*location & 0xfff) | hi20;
212 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
216 static int apply_r_riscv_call_rela(struct module *me, u32 *location,
219 s64 offset = (void *)v - (void *)location;
223 if (offset != fill_v) {
225 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
226 me->name, v, location);
230 hi20 = (offset + 0x800) & 0xfffff000;
231 lo12 = (offset - hi20) & 0xfff;
232 *location = (*location & 0xfff) | hi20;
233 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
237 static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
243 static int apply_r_riscv_align_rela(struct module *me, u32 *location,
247 "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n",
252 static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
255 *(u32 *)location += (*(u32 *)v);
259 static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
261 [R_RISCV_64] = apply_r_riscv_64_rela,
262 [R_RISCV_BRANCH] = apply_r_riscv_branch_rela,
263 [R_RISCV_JAL] = apply_r_riscv_jal_rela,
264 [R_RISCV_RVC_BRANCH] = apply_r_riscv_rcv_branch_rela,
265 [R_RISCV_RVC_JUMP] = apply_r_riscv_rvc_jump_rela,
266 [R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela,
267 [R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela,
268 [R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela,
269 [R_RISCV_HI20] = apply_r_riscv_hi20_rela,
270 [R_RISCV_LO12_I] = apply_r_riscv_lo12_i_rela,
271 [R_RISCV_LO12_S] = apply_r_riscv_lo12_s_rela,
272 [R_RISCV_GOT_HI20] = apply_r_riscv_got_hi20_rela,
273 [R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela,
274 [R_RISCV_CALL] = apply_r_riscv_call_rela,
275 [R_RISCV_RELAX] = apply_r_riscv_relax_rela,
276 [R_RISCV_ALIGN] = apply_r_riscv_align_rela,
277 [R_RISCV_ADD32] = apply_r_riscv_add32_rela,
280 int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
281 unsigned int symindex, unsigned int relsec,
284 Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
285 int (*handler)(struct module *me, u32 *location, Elf_Addr v);
288 unsigned int i, type;
292 pr_debug("Applying relocate section %u to %u\n", relsec,
293 sechdrs[relsec].sh_info);
295 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
296 /* This is where to make the change */
297 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
299 /* This is the symbol it is referring to */
300 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
301 + ELF_RISCV_R_SYM(rel[i].r_info);
302 if (IS_ERR_VALUE(sym->st_value)) {
303 /* Ignore unresolved weak symbol */
304 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
306 pr_warning("%s: Unknown symbol %s\n",
307 me->name, strtab + sym->st_name);
311 type = ELF_RISCV_R_TYPE(rel[i].r_info);
313 if (type < ARRAY_SIZE(reloc_handlers_rela))
314 handler = reloc_handlers_rela[type];
319 pr_err("%s: Unknown relocation type %u\n",
324 v = sym->st_value + rel[i].r_addend;
326 if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) {
329 for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) {
331 sechdrs[sechdrs[relsec].sh_info].sh_addr
333 u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info);
335 /* Find the corresponding HI20 relocation entry */
336 if (hi20_loc == sym->st_value
337 && (hi20_type == R_RISCV_PCREL_HI20
338 || hi20_type == R_RISCV_GOT_HI20)) {
341 (Elf_Sym *)sechdrs[symindex].sh_addr
342 + ELF_RISCV_R_SYM(rel[j].r_info);
348 u64 offset = hi20_sym_val - hi20_loc;
349 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)
350 && hi20_type == R_RISCV_GOT_HI20) {
351 offset = module_emit_got_entry(
353 offset = offset - hi20_loc;
355 hi20 = (offset + 0x800) & 0xfffff000;
356 lo12 = offset - hi20;
362 if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
364 "%s: Can not find HI20 relocation information\n",
370 res = handler(me, location, v);