1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Copyright (C) 2017 Zihao Yu
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>
18 * The auipc+jalr instruction pair can reach any PC-relative offset
19 * in the range [-2^31 - 2^11, 2^31 - 2^11)
21 static bool riscv_insn_valid_32bit_offset(ptrdiff_t val)
26 return (-(1L << 31) - (1L << 11)) <= val && val < ((1L << 31) - (1L << 11));
30 static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v)
33 pr_err("%s: value %016llx out of range for 32-bit field\n",
34 me->name, (long long)v);
41 static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v)
47 static int apply_r_riscv_branch_rela(struct module *me, u32 *location,
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);
56 *location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1;
60 static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
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);
69 *location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1;
73 static int apply_r_riscv_rvc_branch_rela(struct module *me, u32 *location,
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);
83 *(u16 *)location = (*(u16 *)location & 0xe383) |
84 imm8 | imm7_6 | imm5 | imm4_3 | imm2_1;
88 static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location,
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);
101 *(u16 *)location = (*(u16 *)location & 0xe003) |
102 imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1;
106 static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location,
109 ptrdiff_t offset = (void *)v - (void *)location;
112 if (!riscv_insn_valid_32bit_offset(offset)) {
114 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
115 me->name, (long long)v, location);
119 hi20 = (offset + 0x800) & 0xfffff000;
120 *location = (*location & 0xfff) | hi20;
124 static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location,
128 * v is the lo12 value to fill. It is calculated before calling this
131 *location = (*location & 0xfffff) | ((v & 0xfff) << 20);
135 static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
139 * v is the lo12 value to fill. It is calculated before calling this
142 u32 imm11_5 = (v & 0xfe0) << (31 - 11);
143 u32 imm4_0 = (v & 0x1f) << (11 - 4);
145 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
149 static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,
154 if (IS_ENABLED(CONFIG_CMODEL_MEDLOW)) {
156 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
157 me->name, (long long)v, location);
161 hi20 = ((s32)v + 0x800) & 0xfffff000;
162 *location = (*location & 0xfff) | hi20;
166 static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,
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);
176 static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,
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;
188 static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,
191 ptrdiff_t offset = (void *)v - (void *)location;
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;
200 "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n",
201 me->name, (long long)v, location);
205 hi20 = (offset + 0x800) & 0xfffff000;
206 *location = (*location & 0xfff) | hi20;
210 static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
213 ptrdiff_t offset = (void *)v - (void *)location;
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;
223 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
224 me->name, (long long)v, location);
229 hi20 = (offset + 0x800) & 0xfffff000;
230 lo12 = (offset - hi20) & 0xfff;
231 *location = (*location & 0xfff) | hi20;
232 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
236 static int apply_r_riscv_call_rela(struct module *me, u32 *location,
239 ptrdiff_t offset = (void *)v - (void *)location;
242 if (!riscv_insn_valid_32bit_offset(offset)) {
244 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
245 me->name, (long long)v, location);
249 hi20 = (offset + 0x800) & 0xfffff000;
250 lo12 = (offset - hi20) & 0xfff;
251 *location = (*location & 0xfff) | hi20;
252 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
256 static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
262 static int apply_r_riscv_align_rela(struct module *me, u32 *location,
266 "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n",
271 static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
274 *(u32 *)location += (u32)v;
278 static int apply_r_riscv_add64_rela(struct module *me, u32 *location,
281 *(u64 *)location += (u64)v;
285 static int apply_r_riscv_sub32_rela(struct module *me, u32 *location,
288 *(u32 *)location -= (u32)v;
292 static int apply_r_riscv_sub64_rela(struct module *me, u32 *location,
295 *(u64 *)location -= (u64)v;
299 static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
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,
324 int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
325 unsigned int symindex, unsigned int relsec,
328 Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
329 int (*handler)(struct module *me, u32 *location, Elf_Addr v);
332 unsigned int i, type;
336 pr_debug("Applying relocate section %u to %u\n", relsec,
337 sechdrs[relsec].sh_info);
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
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)
350 pr_warn("%s: Unknown symbol %s\n",
351 me->name, strtab + sym->st_name);
355 type = ELF_RISCV_R_TYPE(rel[i].r_info);
357 if (type < ARRAY_SIZE(reloc_handlers_rela))
358 handler = reloc_handlers_rela[type];
363 pr_err("%s: Unknown relocation type %u\n",
368 v = sym->st_value + rel[i].r_addend;
370 if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) {
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
377 u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info);
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)) {
385 (Elf_Sym *)sechdrs[symindex].sh_addr
386 + ELF_RISCV_R_SYM(rel[j].r_info);
387 unsigned long hi20_sym_val =
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(
397 offset = offset - hi20_loc;
399 hi20 = (offset + 0x800) & 0xfffff000;
400 lo12 = offset - hi20;
406 if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
408 "%s: Can not find HI20 relocation information\n",
414 res = handler(me, location, v);
422 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
423 void *module_alloc(unsigned long size)
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));
432 static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
433 const Elf_Shdr *sechdrs,
436 const Elf_Shdr *s, *se;
437 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
439 for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) {
440 if (strcmp(name, secstrs + s->sh_name) == 0)
447 int module_finalize(const Elf_Ehdr *hdr,
448 const Elf_Shdr *sechdrs,
453 s = find_section(hdr, sechdrs, ".alternative");
455 apply_module_alternatives((void *)s->sh_addr, s->sh_size);