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>
19 #include <linux/vmalloc.h>
20 #include <linux/sizes.h>
21 #include <asm/pgtable.h>
22 #include <asm/sections.h>
24 static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v)
27 pr_err("%s: value %016llx out of range for 32-bit field\n",
28 me->name, (long long)v);
35 static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v)
41 static int apply_r_riscv_branch_rela(struct module *me, u32 *location,
44 ptrdiff_t offset = (void *)v - (void *)location;
45 u32 imm12 = (offset & 0x1000) << (31 - 12);
46 u32 imm11 = (offset & 0x800) >> (11 - 7);
47 u32 imm10_5 = (offset & 0x7e0) << (30 - 10);
48 u32 imm4_1 = (offset & 0x1e) << (11 - 4);
50 *location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1;
54 static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
57 ptrdiff_t offset = (void *)v - (void *)location;
58 u32 imm20 = (offset & 0x100000) << (31 - 20);
59 u32 imm19_12 = (offset & 0xff000);
60 u32 imm11 = (offset & 0x800) << (20 - 11);
61 u32 imm10_1 = (offset & 0x7fe) << (30 - 10);
63 *location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1;
67 static int apply_r_riscv_rcv_branch_rela(struct module *me, u32 *location,
70 ptrdiff_t offset = (void *)v - (void *)location;
71 u16 imm8 = (offset & 0x100) << (12 - 8);
72 u16 imm7_6 = (offset & 0xc0) >> (6 - 5);
73 u16 imm5 = (offset & 0x20) >> (5 - 2);
74 u16 imm4_3 = (offset & 0x18) << (12 - 5);
75 u16 imm2_1 = (offset & 0x6) << (12 - 10);
77 *(u16 *)location = (*(u16 *)location & 0xe383) |
78 imm8 | imm7_6 | imm5 | imm4_3 | imm2_1;
82 static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location,
85 ptrdiff_t offset = (void *)v - (void *)location;
86 u16 imm11 = (offset & 0x800) << (12 - 11);
87 u16 imm10 = (offset & 0x400) >> (10 - 8);
88 u16 imm9_8 = (offset & 0x300) << (12 - 11);
89 u16 imm7 = (offset & 0x80) >> (7 - 6);
90 u16 imm6 = (offset & 0x40) << (12 - 11);
91 u16 imm5 = (offset & 0x20) >> (5 - 2);
92 u16 imm4 = (offset & 0x10) << (12 - 5);
93 u16 imm3_1 = (offset & 0xe) << (12 - 10);
95 *(u16 *)location = (*(u16 *)location & 0xe003) |
96 imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1;
100 static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location,
103 ptrdiff_t offset = (void *)v - (void *)location;
106 if (offset != (s32)offset) {
108 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
109 me->name, (long long)v, location);
113 hi20 = (offset + 0x800) & 0xfffff000;
114 *location = (*location & 0xfff) | hi20;
118 static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location,
122 * v is the lo12 value to fill. It is calculated before calling this
125 *location = (*location & 0xfffff) | ((v & 0xfff) << 20);
129 static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
133 * v is the lo12 value to fill. It is calculated before calling this
136 u32 imm11_5 = (v & 0xfe0) << (31 - 11);
137 u32 imm4_0 = (v & 0x1f) << (11 - 4);
139 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
143 static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,
148 if (IS_ENABLED(CMODEL_MEDLOW)) {
150 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
151 me->name, (long long)v, location);
155 hi20 = ((s32)v + 0x800) & 0xfffff000;
156 *location = (*location & 0xfff) | hi20;
160 static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,
163 /* Skip medlow checking because of filtering by HI20 already */
164 s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
165 s32 lo12 = ((s32)v - hi20);
166 *location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20);
170 static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,
173 /* Skip medlow checking because of filtering by HI20 already */
174 s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
175 s32 lo12 = ((s32)v - hi20);
176 u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11);
177 u32 imm4_0 = (lo12 & 0x1f) << (11 - 4);
178 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
182 static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,
185 ptrdiff_t offset = (void *)v - (void *)location;
188 /* Always emit the got entry */
189 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
190 offset = module_emit_got_entry(me, v);
191 offset = (void *)offset - (void *)location;
194 "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n",
195 me->name, (long long)v, location);
199 hi20 = (offset + 0x800) & 0xfffff000;
200 *location = (*location & 0xfff) | hi20;
204 static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
207 ptrdiff_t offset = (void *)v - (void *)location;
211 if (offset != fill_v) {
212 /* Only emit the plt entry if offset over 32-bit range */
213 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
214 offset = module_emit_plt_entry(me, v);
215 offset = (void *)offset - (void *)location;
218 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
219 me->name, (long long)v, location);
224 hi20 = (offset + 0x800) & 0xfffff000;
225 lo12 = (offset - hi20) & 0xfff;
226 *location = (*location & 0xfff) | hi20;
227 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
231 static int apply_r_riscv_call_rela(struct module *me, u32 *location,
234 ptrdiff_t offset = (void *)v - (void *)location;
238 if (offset != fill_v) {
240 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
241 me->name, (long long)v, location);
245 hi20 = (offset + 0x800) & 0xfffff000;
246 lo12 = (offset - hi20) & 0xfff;
247 *location = (*location & 0xfff) | hi20;
248 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
252 static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
258 static int apply_r_riscv_align_rela(struct module *me, u32 *location,
262 "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n",
267 static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
270 *(u32 *)location += (u32)v;
274 static int apply_r_riscv_sub32_rela(struct module *me, u32 *location,
277 *(u32 *)location -= (u32)v;
281 static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
283 [R_RISCV_32] = apply_r_riscv_32_rela,
284 [R_RISCV_64] = apply_r_riscv_64_rela,
285 [R_RISCV_BRANCH] = apply_r_riscv_branch_rela,
286 [R_RISCV_JAL] = apply_r_riscv_jal_rela,
287 [R_RISCV_RVC_BRANCH] = apply_r_riscv_rcv_branch_rela,
288 [R_RISCV_RVC_JUMP] = apply_r_riscv_rvc_jump_rela,
289 [R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela,
290 [R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela,
291 [R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela,
292 [R_RISCV_HI20] = apply_r_riscv_hi20_rela,
293 [R_RISCV_LO12_I] = apply_r_riscv_lo12_i_rela,
294 [R_RISCV_LO12_S] = apply_r_riscv_lo12_s_rela,
295 [R_RISCV_GOT_HI20] = apply_r_riscv_got_hi20_rela,
296 [R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela,
297 [R_RISCV_CALL] = apply_r_riscv_call_rela,
298 [R_RISCV_RELAX] = apply_r_riscv_relax_rela,
299 [R_RISCV_ALIGN] = apply_r_riscv_align_rela,
300 [R_RISCV_ADD32] = apply_r_riscv_add32_rela,
301 [R_RISCV_SUB32] = apply_r_riscv_sub32_rela,
304 int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
305 unsigned int symindex, unsigned int relsec,
308 Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
309 int (*handler)(struct module *me, u32 *location, Elf_Addr v);
312 unsigned int i, type;
316 pr_debug("Applying relocate section %u to %u\n", relsec,
317 sechdrs[relsec].sh_info);
319 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
320 /* This is where to make the change */
321 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
323 /* This is the symbol it is referring to */
324 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
325 + ELF_RISCV_R_SYM(rel[i].r_info);
326 if (IS_ERR_VALUE(sym->st_value)) {
327 /* Ignore unresolved weak symbol */
328 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
330 pr_warning("%s: Unknown symbol %s\n",
331 me->name, strtab + sym->st_name);
335 type = ELF_RISCV_R_TYPE(rel[i].r_info);
337 if (type < ARRAY_SIZE(reloc_handlers_rela))
338 handler = reloc_handlers_rela[type];
343 pr_err("%s: Unknown relocation type %u\n",
348 v = sym->st_value + rel[i].r_addend;
350 if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) {
353 for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) {
354 unsigned long hi20_loc =
355 sechdrs[sechdrs[relsec].sh_info].sh_addr
357 u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info);
359 /* Find the corresponding HI20 relocation entry */
360 if (hi20_loc == sym->st_value
361 && (hi20_type == R_RISCV_PCREL_HI20
362 || hi20_type == R_RISCV_GOT_HI20)) {
365 (Elf_Sym *)sechdrs[symindex].sh_addr
366 + ELF_RISCV_R_SYM(rel[j].r_info);
367 unsigned long hi20_sym_val =
372 size_t offset = hi20_sym_val - hi20_loc;
373 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)
374 && hi20_type == R_RISCV_GOT_HI20) {
375 offset = module_emit_got_entry(
377 offset = offset - hi20_loc;
379 hi20 = (offset + 0x800) & 0xfffff000;
380 lo12 = offset - hi20;
386 if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
388 "%s: Can not find HI20 relocation information\n",
394 res = handler(me, location, v);
402 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
403 #define VMALLOC_MODULE_START \
404 max(PFN_ALIGN((unsigned long)&_end - SZ_2G), VMALLOC_START)
405 void *module_alloc(unsigned long size)
407 return __vmalloc_node_range(size, 1, VMALLOC_MODULE_START,
408 VMALLOC_END, GFP_KERNEL,
409 PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
410 __builtin_return_address(0));