arch/microblaze/kernel/module.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
   4  * Copyright (C) 2007-2009 PetaLogix
   5  */
   6
   7 #include <linux/export.h>
   8 #include <linux/moduleloader.h>
   9 #include <linux/kernel.h>
  10 #include <linux/elf.h>
  11 #include <linux/vmalloc.h>
  12 #include <linux/fs.h>
  13 #include <linux/string.h>
  14
  15 #include <asm/pgtable.h>
  16 #include <asm/cacheflush.h>
  17
  18 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
  19         unsigned int symindex, unsigned int relsec, struct module *module)
  20 {
  21
  22         unsigned int i;
  23         Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
  24         Elf32_Sym *sym;
  25         unsigned long int *location;
  26         unsigned long int value;
  27 #if __GNUC__ < 4
  28         unsigned long int old_value;
  29 #endif
  30
  31         pr_debug("Applying add relocation section %u to %u\n",
  32                 relsec, sechdrs[relsec].sh_info);
  33
  34         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
  35
  36                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
  37                                 rela[i].r_offset;
  38                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr +
  39                         ELF32_R_SYM(rela[i].r_info);
  40                 value = sym->st_value + rela[i].r_addend;
  41
  42                 switch (ELF32_R_TYPE(rela[i].r_info)) {
  43
  44                 /*
  45                  * Be careful! mb-gcc / mb-ld splits the relocs between the
  46                  * text and the reloc table. In general this means we must
  47                  * read the current contents of (*location), add any offset
  48                  * then store the result back in
  49                  */
  50
  51                 case R_MICROBLAZE_32:
  52 #if __GNUC__ < 4
  53                         old_value = *location;
  54                         *location = value + old_value;
  55
  56                         pr_debug("R_MICROBLAZE_32 (%08lx->%08lx)\n",
  57                                 old_value, value);
  58 #else
  59                         *location = value;
  60 #endif
  61                         break;
  62
  63                 case R_MICROBLAZE_64:
  64 #if __GNUC__ < 4
  65                         /* Split relocs only required/used pre gcc4.1.1 */
  66                         old_value = ((location[0] & 0x0000FFFF) << 16) |
  67                                         (location[1] & 0x0000FFFF);
  68                         value += old_value;
  69 #endif
  70                         location[0] = (location[0] & 0xFFFF0000) |
  71                                         (value >> 16);
  72                         location[1] = (location[1] & 0xFFFF0000) |
  73                                         (value & 0xFFFF);
  74 #if __GNUC__ < 4
  75                         pr_debug("R_MICROBLAZE_64 (%08lx->%08lx)\n",
  76                                 old_value, value);
  77 #endif
  78                         break;
  79
  80                 case R_MICROBLAZE_64_PCREL:
  81 #if __GNUC__ < 4
  82                         old_value = (location[0] & 0xFFFF) << 16 |
  83                                 (location[1] & 0xFFFF);
  84                         value -= old_value;
  85 #endif
  86                         value -= (unsigned long int)(location) + 4;
  87                         location[0] = (location[0] & 0xFFFF0000) |
  88                                         (value >> 16);
  89                         location[1] = (location[1] & 0xFFFF0000) |
  90                                         (value & 0xFFFF);
  91                         pr_debug("R_MICROBLAZE_64_PCREL (%08lx)\n",
  92                                 value);
  93                         break;
  94
  95                 case R_MICROBLAZE_32_PCREL_LO:
  96                         pr_debug("R_MICROBLAZE_32_PCREL_LO\n");
  97                         break;
  98
  99                 case R_MICROBLAZE_64_NONE:
 100                         pr_debug("R_MICROBLAZE_64_NONE\n");
 101                         break;
 102
 103                 case R_MICROBLAZE_NONE:
 104                         pr_debug("R_MICROBLAZE_NONE\n");
 105                         break;
 106
 107                 default:
 108                         pr_err("module %s: Unknown relocation: %u\n",
 109                                 module->name,
 110                                 ELF32_R_TYPE(rela[i].r_info));
 111                         return -ENOEXEC;
 112                 }
 113         }
 114         return 0;
 115 }
 116
 117 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
 118                 struct module *module)
 119 {
 120         flush_dcache();
 121         return 0;
 122 }