| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | #include <linux/moduleloader.h> |
| 3 | #include <linux/elf.h> |
| 4 | #include <linux/vmalloc.h> |
| 5 | #include <linux/fs.h> |
| 6 | #include <linux/string.h> |
| 7 | #include <linux/kernel.h> |
| 8 | |
| 9 | int apply_relocate_add(Elf32_Shdr *sechdrs, |
| 10 | const char *strtab, |
| 11 | unsigned int symindex, |
| 12 | unsigned int relsec, |
| 13 | struct module *me) |
| 14 | { |
| 15 | unsigned int i; |
| 16 | Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr; |
| 17 | |
| 18 | pr_debug("Applying relocate section %u to %u\n", relsec, |
| 19 | sechdrs[relsec].sh_info); |
| 20 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) { |
| 21 | /* This is where to make the change */ |
| 22 | uint32_t *loc = |
| 23 | (uint32_t *)(sechdrs[sechdrs[relsec].sh_info].sh_addr |
| 24 | + rela[i].r_offset); |
| 25 | /* This is the symbol it is referring to. Note that all |
| 26 | undefined symbols have been resolved. */ |
| 27 | Elf32_Sym *sym = (Elf32_Sym *)sechdrs[symindex].sh_addr |
| 28 | + ELF32_R_SYM(rela[i].r_info); |
| 29 | uint32_t v = sym->st_value + rela[i].r_addend; |
| 30 | |
| 31 | switch (ELF32_R_TYPE(rela[i].r_info)) { |
| 32 | case R_H8_DIR24R8: |
| 33 | loc = (uint32_t *)((uint32_t)loc - 1); |
| 34 | *loc = (*loc & 0xff000000) | ((*loc & 0xffffff) + v); |
| 35 | break; |
| 36 | case R_H8_DIR24A8: |
| 37 | if (ELF32_R_SYM(rela[i].r_info)) |
| 38 | *loc += v; |
| 39 | break; |
| 40 | case R_H8_DIR32: |
| 41 | case R_H8_DIR32A16: |
| 42 | *loc += v; |
| 43 | break; |
| 44 | case R_H8_PCREL16: |
| 45 | v -= (unsigned long)loc + 2; |
| 46 | if ((Elf32_Sword)v > 0x7fff || |
| 47 | (Elf32_Sword)v < -(Elf32_Sword)0x8000) |
| 48 | goto overflow; |
| 49 | else |
| 50 | *(unsigned short *)loc = v; |
| 51 | break; |
| 52 | case R_H8_PCREL8: |
| 53 | v -= (unsigned long)loc + 1; |
| 54 | if ((Elf32_Sword)v > 0x7f || |
| 55 | (Elf32_Sword)v < -(Elf32_Sword)0x80) |
| 56 | goto overflow; |
| 57 | else |
| 58 | *(unsigned char *)loc = v; |
| 59 | break; |
| 60 | default: |
| 61 | pr_err("module %s: Unknown relocation: %u\n", |
| 62 | me->name, ELF32_R_TYPE(rela[i].r_info)); |
| 63 | return -ENOEXEC; |
| 64 | } |
| 65 | } |
| 66 | return 0; |
| 67 | overflow: |
| 68 | pr_err("module %s: relocation offset overflow: %08x\n", |
| 69 | me->name, rela[i].r_offset); |
| 70 | return -ENOEXEC; |
| 71 | } |