root/arch/h8300/kernel/module.c

DEFINITIONS

1. apply_relocate_add

   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 }