arch/csky/kernel/module.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/moduleloader.h>
   5 #include <linux/elf.h>
   6 #include <linux/mm.h>
   7 #include <linux/vmalloc.h>
   8 #include <linux/slab.h>
   9 #include <linux/fs.h>
  10 #include <linux/string.h>
  11 #include <linux/kernel.h>
  12 #include <linux/spinlock.h>
  13 #include <asm/pgtable.h>
  14
  15 #if defined(__CSKYABIV2__)
  16 #define IS_BSR32(hi16, lo16)            (((hi16) & 0xFC00) == 0xE000)
  17 #define IS_JSRI32(hi16, lo16)           ((hi16) == 0xEAE0)
  18
  19 #define CHANGE_JSRI_TO_LRW(addr) do {                                   \
  20         *(uint16_t *)(addr) = (*(uint16_t *)(addr) & 0xFF9F) | 0x001a;  \
  21         *((uint16_t *)(addr) + 1) = *((uint16_t *)(addr) + 1) & 0xFFFF; \
  22 } while (0)
  23
  24 #define SET_JSR32_R26(addr) do {                \
  25         *(uint16_t *)(addr) = 0xE8Fa;           \
  26         *((uint16_t *)(addr) + 1) = 0x0000;     \
  27 } while (0)
  28 #endif
  29
  30 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
  31                 unsigned int symindex, unsigned int relsec, struct module *me)
  32 {
  33         unsigned int i;
  34         Elf32_Rela      *rel = (void *) sechdrs[relsec].sh_addr;
  35         Elf32_Sym       *sym;
  36         uint32_t        *location;
  37         short           *temp;
  38 #if defined(__CSKYABIV2__)
  39         uint16_t        *location_tmp;
  40 #endif
  41
  42         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  43                 /* This is where to make the change */
  44                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  45                                                         + rel[i].r_offset;
  46                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
  47                                                 + ELF32_R_SYM(rel[i].r_info);
  48
  49                 switch (ELF32_R_TYPE(rel[i].r_info)) {
  50                 case R_CSKY_32:
  51                         /* We add the value into the location given */
  52                         *location = rel[i].r_addend + sym->st_value;
  53                         break;
  54                 case R_CSKY_PC32:
  55                         /* Add the value, subtract its postition */
  56                         *location = rel[i].r_addend + sym->st_value
  57                                                         - (uint32_t)location;
  58                         break;
  59                 case R_CSKY_PCRELJSR_IMM11BY2:
  60                         break;
  61                 case R_CSKY_PCRELJSR_IMM26BY2:
  62 #if defined(__CSKYABIV2__)
  63                         location_tmp = (uint16_t *)location;
  64                         if (IS_BSR32(*location_tmp, *(location_tmp + 1)))
  65                                 break;
  66
  67                         if (IS_JSRI32(*location_tmp, *(location_tmp + 1))) {
  68                                 /* jsri 0x...  --> lrw r26, 0x... */
  69                                 CHANGE_JSRI_TO_LRW(location);
  70                                 /* lsli r0, r0 --> jsr r26 */
  71                                 SET_JSR32_R26(location + 1);
  72                         }
  73 #endif
  74                         break;
  75                 case R_CSKY_ADDR_HI16:
  76                         temp = ((short  *)location) + 1;
  77                         *temp = (short)
  78                                 ((rel[i].r_addend + sym->st_value) >> 16);
  79                         break;
  80                 case R_CSKY_ADDR_LO16:
  81                         temp = ((short  *)location) + 1;
  82                         *temp = (short)
  83                                 ((rel[i].r_addend + sym->st_value) & 0xffff);
  84                         break;
  85                 default:
  86                         pr_err("module %s: Unknown relocation: %u\n",
  87                                 me->name, ELF32_R_TYPE(rel[i].r_info));
  88                         return -ENOEXEC;
  89                 }
  90         }
  91         return 0;
  92 }