1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/moduleloader.h>
4 #include <linux/vmalloc.h>
6 #include <linux/string.h>
7 #include <linux/kernel.h>
9 int apply_relocate_add(Elf32_Shdr *sechdrs,
11 unsigned int symindex,
16 Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
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 */
23 (uint32_t *)(sechdrs[sechdrs[relsec].sh_info].sh_addr
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;
31 switch (ELF32_R_TYPE(rela[i].r_info)) {
33 loc = (uint32_t *)((uint32_t)loc - 1);
34 *loc = (*loc & 0xff000000) | ((*loc & 0xffffff) + v);
37 if (ELF32_R_SYM(rela[i].r_info))
45 v -= (unsigned long)loc + 2;
46 if ((Elf32_Sword)v > 0x7fff ||
47 (Elf32_Sword)v < -(Elf32_Sword)0x8000)
50 *(unsigned short *)loc = v;
53 v -= (unsigned long)loc + 1;
54 if ((Elf32_Sword)v > 0x7f ||
55 (Elf32_Sword)v < -(Elf32_Sword)0x80)
58 *(unsigned char *)loc = v;
61 pr_err("module %s: Unknown relocation: %u\n",
62 me->name, ELF32_R_TYPE(rela[i].r_info));
68 pr_err("module %s: relocation offset overflow: %08x\n",
69 me->name, rela[i].r_offset);