LXR linux/arch/c6x/kernel/module.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  Port on Texas Instruments TMS320C6x architecture
   4 *
   5 *  Copyright (C) 2005, 2009, 2010, 2011 Texas Instruments Incorporated
   6 *  Author: Thomas Charleux (thomas.charleux@jaluna.com)
   7 */
   8#include <linux/moduleloader.h>
   9#include <linux/elf.h>
  10#include <linux/vmalloc.h>
  11#include <linux/kernel.h>
  12
  13static inline int fixup_pcr(u32 *ip, Elf32_Addr dest, u32 maskbits, int shift)
  14{
  15        u32 opcode;
  16        long ep = (long)ip & ~31;
  17        long delta = ((long)dest - ep) >> 2;
  18        long mask = (1 << maskbits) - 1;
  19
  20        if ((delta >> (maskbits - 1)) == 0 ||
  21            (delta >> (maskbits - 1)) == -1) {
  22                opcode = *ip;
  23                opcode &= ~(mask << shift);
  24                opcode |= ((delta & mask) << shift);
  25                *ip = opcode;
  26
  27                pr_debug("REL PCR_S%d[%p] dest[%p] opcode[%08x]\n",
  28                         maskbits, ip, (void *)dest, opcode);
  29
  30                return 0;
  31        }
  32        pr_err("PCR_S%d reloc %p -> %p out of range!\n",
  33               maskbits, ip, (void *)dest);
  34
  35        return -1;
  36}
  37
  38/*
  39 * apply a RELA relocation
  40 */
  41int apply_relocate_add(Elf32_Shdr *sechdrs,
  42                       const char *strtab,
  43                       unsigned int symindex,
  44                       unsigned int relsec,
  45                       struct module *me)
  46{
  47        Elf32_Rela *rel = (void *) sechdrs[relsec].sh_addr;
  48        Elf_Sym *sym;
  49        u32 *location, opcode;
  50        unsigned int i;
  51        Elf32_Addr v;
  52        Elf_Addr offset = 0;
  53
  54        pr_debug("Applying relocate section %u to %u with offset 0x%x\n",
  55                 relsec, sechdrs[relsec].sh_info, offset);
  56
  57        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  58                /* This is where to make the change */
  59                location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  60                        + rel[i].r_offset - offset;
  61
  62                /* This is the symbol it is referring to.  Note that all
  63                   undefined symbols have been resolved.  */
  64                sym = (Elf_Sym *)sechdrs[symindex].sh_addr
  65                        + ELF32_R_SYM(rel[i].r_info);
  66
  67                /* this is the adjustment to be made */
  68                v = sym->st_value + rel[i].r_addend;
  69
  70                switch (ELF32_R_TYPE(rel[i].r_info)) {
  71                case R_C6000_ABS32:
  72                        pr_debug("RELA ABS32: [%p] = 0x%x\n", location, v);
  73                        *location = v;
  74                        break;
  75                case R_C6000_ABS16:
  76                        pr_debug("RELA ABS16: [%p] = 0x%x\n", location, v);
  77                        *(u16 *)location = v;
  78                        break;
  79                case R_C6000_ABS8:
  80                        pr_debug("RELA ABS8: [%p] = 0x%x\n", location, v);
  81                        *(u8 *)location = v;
  82                        break;
  83                case R_C6000_ABS_L16:
  84                        opcode = *location;
  85                        opcode &= ~0x7fff80;
  86                        opcode |= ((v & 0xffff) << 7);
  87                        pr_debug("RELA ABS_L16[%p] v[0x%x] opcode[0x%x]\n",
  88                                 location, v, opcode);
  89                        *location = opcode;
  90                        break;
  91                case R_C6000_ABS_H16:
  92                        opcode = *location;
  93                        opcode &= ~0x7fff80;
  94                        opcode |= ((v >> 9) & 0x7fff80);
  95                        pr_debug("RELA ABS_H16[%p] v[0x%x] opcode[0x%x]\n",
  96                                 location, v, opcode);
  97                        *location = opcode;
  98                        break;
  99                case R_C6000_PCR_S21:
 100                        if (fixup_pcr(location, v, 21, 7))
 101                                return -ENOEXEC;
 102                        break;
 103                case R_C6000_PCR_S12:
 104                        if (fixup_pcr(location, v, 12, 16))
 105                                return -ENOEXEC;
 106                        break;
 107                case R_C6000_PCR_S10:
 108                        if (fixup_pcr(location, v, 10, 13))
 109                                return -ENOEXEC;
 110                        break;
 111                default:
 112                        pr_err("module %s: Unknown RELA relocation: %u\n",
 113                               me->name, ELF32_R_TYPE(rel[i].r_info));
 114                        return -ENOEXEC;
 115                }
 116        }
 117
 118        return 0;
 119}
 120