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