LXR linux/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 <asm/unaligned.h>
  22#include <asm/dwarf.h>
  23
  24int 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#ifdef CONFIG_SUPERH64
  50                /* For text addresses, bit2 of the st_other field indicates
  51                 * whether the symbol is SHmedia (1) or SHcompact (0).  If
  52                 * SHmedia, the LSB of the symbol needs to be asserted
  53                 * for the CPU to be in SHmedia mode when it starts executing
  54                 * the branch target. */
  55                relocation |= !!(sym->st_other & 4);
  56#endif
  57
  58                switch (ELF32_R_TYPE(rel[i].r_info)) {
  59                case R_SH_NONE:
  60                        break;
  61                case R_SH_DIR32:
  62                        value = get_unaligned(location);
  63                        value += relocation;
  64                        put_unaligned(value, location);
  65                        break;
  66                case R_SH_REL32:
  67                        relocation = (relocation - (Elf32_Addr) location);
  68                        value = get_unaligned(location);
  69                        value += relocation;
  70                        put_unaligned(value, location);
  71                        break;
  72                case R_SH_IMM_LOW16:
  73                        *location = (*location & ~0x3fffc00) |
  74                                ((relocation & 0xffff) << 10);
  75                        break;
  76                case R_SH_IMM_MEDLOW16:
  77                        *location = (*location & ~0x3fffc00) |
  78                                (((relocation >> 16) & 0xffff) << 10);
  79                        break;
  80                case R_SH_IMM_LOW16_PCREL:
  81                        relocation -= (Elf32_Addr) location;
  82                        *location = (*location & ~0x3fffc00) |
  83                                ((relocation & 0xffff) << 10);
  84                        break;
  85                case R_SH_IMM_MEDLOW16_PCREL:
  86                        relocation -= (Elf32_Addr) location;
  87                        *location = (*location & ~0x3fffc00) |
  88                                (((relocation >> 16) & 0xffff) << 10);
  89                        break;
  90                default:
  91                        printk(KERN_ERR "module %s: Unknown relocation: %u\n",
  92                               me->name, ELF32_R_TYPE(rel[i].r_info));
  93                        return -ENOEXEC;
  94                }
  95        }
  96        return 0;
  97}
  98
  99int module_finalize(const Elf_Ehdr *hdr,
 100                    const Elf_Shdr *sechdrs,
 101                    struct module *me)
 102{
 103        int ret = 0;
 104
 105        ret |= module_dwarf_finalize(hdr, sechdrs, me);
 106
 107        return ret;
 108}
 109
 110void module_arch_cleanup(struct module *mod)
 111{
 112        module_dwarf_cleanup(mod);
 113}
 114