LXR linux/arch/nios2/kernel/module.c

   1/*
   2 * Kernel module support for Nios II.
   3 *
   4 * Copyright (C) 2004 Microtronix Datacom Ltd.
   5 *   Written by Wentao Xu <xuwentao@microtronix.com>
   6 * Copyright (C) 2001, 2003 Rusty Russell
   7 *
   8 * This file is subject to the terms and conditions of the GNU General
   9 * Public License.  See the file COPYING in the main directory of this
  10 * archive for more details.
  11 */
  12
  13#include <linux/moduleloader.h>
  14#include <linux/elf.h>
  15#include <linux/mm.h>
  16#include <linux/vmalloc.h>
  17#include <linux/slab.h>
  18#include <linux/fs.h>
  19#include <linux/string.h>
  20#include <linux/kernel.h>
  21
  22#include <asm/pgtable.h>
  23#include <asm/cacheflush.h>
  24
  25/*
  26 * Modules should NOT be allocated with kmalloc for (obvious) reasons.
  27 * But we do it for now to avoid relocation issues. CALL26/PCREL26 cannot reach
  28 * from 0x80000000 (vmalloc area) to 0xc00000000 (kernel) (kmalloc returns
  29 * addresses in 0xc0000000)
  30 */
  31void *module_alloc(unsigned long size)
  32{
  33        if (size == 0)
  34                return NULL;
  35        return kmalloc(size, GFP_KERNEL);
  36}
  37
  38/* Free memory returned from module_alloc */
  39void module_memfree(void *module_region)
  40{
  41        kfree(module_region);
  42}
  43
  44int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
  45                        unsigned int symindex, unsigned int relsec,
  46                        struct module *mod)
  47{
  48        unsigned int i;
  49        Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
  50
  51        pr_debug("Applying relocate section %u to %u\n", relsec,
  52                 sechdrs[relsec].sh_info);
  53
  54        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
  55                /* This is where to make the change */
  56                uint32_t word;
  57                uint32_t *loc
  58                        = ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  59                           + rela[i].r_offset);
  60                /* This is the symbol it is referring to.  Note that all
  61                   undefined symbols have been resolved.  */
  62                Elf32_Sym *sym
  63                        = ((Elf32_Sym *)sechdrs[symindex].sh_addr
  64                                + ELF32_R_SYM(rela[i].r_info));
  65                uint32_t v = sym->st_value + rela[i].r_addend;
  66
  67                pr_debug("reltype %d 0x%x name:<%s>\n",
  68                        ELF32_R_TYPE(rela[i].r_info),
  69                        rela[i].r_offset, strtab + sym->st_name);
  70
  71                switch (ELF32_R_TYPE(rela[i].r_info)) {
  72                case R_NIOS2_NONE:
  73                        break;
  74                case R_NIOS2_BFD_RELOC_32:
  75                        *loc += v;
  76                        break;
  77                case R_NIOS2_PCREL16:
  78                        v -= (uint32_t)loc + 4;
  79                        if ((int32_t)v > 0x7fff ||
  80                                (int32_t)v < -(int32_t)0x8000) {
  81                                pr_err("module %s: relocation overflow\n",
  82                                        mod->name);
  83                                return -ENOEXEC;
  84                        }
  85                        word = *loc;
  86                        *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) |
  87                                (word & 0x3f);
  88                        break;
  89                case R_NIOS2_CALL26:
  90                        if (v & 3) {
  91                                pr_err("module %s: dangerous relocation\n",
  92                                        mod->name);
  93                                return -ENOEXEC;
  94                        }
  95                        if ((v >> 28) != ((uint32_t)loc >> 28)) {
  96                                pr_err("module %s: relocation overflow\n",
  97                                        mod->name);
  98                                return -ENOEXEC;
  99                        }
 100                        *loc = (*loc & 0x3f) | ((v >> 2) << 6);
 101                        break;
 102                case R_NIOS2_HI16:
 103                        word = *loc;
 104                        *loc = ((((word >> 22) << 16) |
 105                                ((v >> 16) & 0xffff)) << 6) | (word & 0x3f);
 106                        break;
 107                case R_NIOS2_LO16:
 108                        word = *loc;
 109                        *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) |
 110                                        (word & 0x3f);
 111                        break;
 112                case R_NIOS2_HIADJ16:
 113                        {
 114                                Elf32_Addr word2;
 115
 116                                word = *loc;
 117                                word2 = ((v >> 16) + ((v >> 15) & 1)) & 0xffff;
 118                                *loc = ((((word >> 22) << 16) | word2) << 6) |
 119                                                (word & 0x3f);
 120                        }
 121                        break;
 122
 123                default:
 124                        pr_err("module %s: Unknown reloc: %u\n",
 125                                mod->name, ELF32_R_TYPE(rela[i].r_info));
 126                        return -ENOEXEC;
 127                }
 128        }
 129
 130        return 0;
 131}
 132
 133int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
 134                        struct module *me)
 135{
 136        flush_cache_all();
 137        return 0;
 138}
 139