arch/sh/kernel/module.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*  Kernel module help for SH.
   3
   4     SHcompact version by Kaz Kojima and Paul Mundt.
   5
   6     SHmedia bits:
   7
   8         Copyright 2004 SuperH (UK) Ltd
   9         Author: Richard Curnow
  10
  11         Based on the sh version, and on code from the sh64-specific parts of
  12         modutils, originally written by Richard Curnow and Ben Gaster.
  13 */
  14 #include <linux/moduleloader.h>
  15 #include <linux/elf.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/bug.h>
  18 #include <linux/fs.h>
  19 #include <linux/string.h>
  20 #include <linux/kernel.h>
  21 #include <linux/unaligned.h>
  22 #include <asm/dwarf.h>
  23
  24 int apply_relocate_add(Elf32_Shdr *sechdrs,
  25                    const char *strtab,
  26                    unsigned int symindex,
  27                    unsigned int relsec,
  28                    struct module *me)
  29 {
  30         unsigned int i;
  31         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
  32         Elf32_Sym *sym;
  33         Elf32_Addr relocation;
  34         uint32_t *location;
  35         uint32_t value;
  36
  37         pr_debug("Applying relocate section %u to %u\n", relsec,
  38                  sechdrs[relsec].sh_info);
  39         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  40                 /* This is where to make the change */
  41                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  42                         + rel[i].r_offset;
  43                 /* This is the symbol it is referring to.  Note that all
  44                    undefined symbols have been resolved.  */
  45                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
  46                         + ELF32_R_SYM(rel[i].r_info);
  47                 relocation = sym->st_value + rel[i].r_addend;
  48
  49                 switch (ELF32_R_TYPE(rel[i].r_info)) {
  50                 case R_SH_NONE:
  51                         break;
  52                 case R_SH_DIR32:
  53                         value = get_unaligned(location);
  54                         value += relocation;
  55                         put_unaligned(value, location);
  56                         break;
  57                 case R_SH_REL32:
  58                         relocation = (relocation - (Elf32_Addr) location);
  59                         value = get_unaligned(location);
  60                         value += relocation;
  61                         put_unaligned(value, location);
  62                         break;
  63                 case R_SH_IMM_LOW16:
  64                         *location = (*location & ~0x3fffc00) |
  65                                 ((relocation & 0xffff) << 10);
  66                         break;
  67                 case R_SH_IMM_MEDLOW16:
  68                         *location = (*location & ~0x3fffc00) |
  69                                 (((relocation >> 16) & 0xffff) << 10);
  70                         break;
  71                 case R_SH_IMM_LOW16_PCREL:
  72                         relocation -= (Elf32_Addr) location;
  73                         *location = (*location & ~0x3fffc00) |
  74                                 ((relocation & 0xffff) << 10);
  75                         break;
  76                 case R_SH_IMM_MEDLOW16_PCREL:
  77                         relocation -= (Elf32_Addr) location;
  78                         *location = (*location & ~0x3fffc00) |
  79                                 (((relocation >> 16) & 0xffff) << 10);
  80                         break;
  81                 default:
  82                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
  83                                me->name, ELF32_R_TYPE(rel[i].r_info));
  84                         return -ENOEXEC;
  85                 }
  86         }
  87         return 0;
  88 }
  89
  90 int module_finalize(const Elf_Ehdr *hdr,
  91                     const Elf_Shdr *sechdrs,
  92                     struct module *me)
  93 {
  94         int ret = 0;
  95
  96         ret |= module_dwarf_finalize(hdr, sechdrs, me);
  97
  98         return ret;
  99 }
 100
 101 void module_arch_cleanup(struct module *mod)
 102 {
 103         module_dwarf_cleanup(mod);
 104 }