1 /* 2 * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu> 3 * Copyright (C) 2007-2009 PetaLogix 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 */ 9 10 #include <linux/export.h> 11 #include <linux/moduleloader.h> 12 #include <linux/kernel.h> 13 #include <linux/elf.h> 14 #include <linux/vmalloc.h> 15 #include <linux/fs.h> 16 #include <linux/string.h> 17 18 #include <asm/pgtable.h> 19 #include <asm/cacheflush.h> 20 21 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, 22 unsigned int symindex, unsigned int relsec, struct module *module) 23 { 24 25 unsigned int i; 26 Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr; 27 Elf32_Sym *sym; 28 unsigned long int *location; 29 unsigned long int value; 30 #if __GNUC__ < 4 31 unsigned long int old_value; 32 #endif 33 34 pr_debug("Applying add relocation section %u to %u\n", 35 relsec, sechdrs[relsec].sh_info); 36 37 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) { 38 39 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + 40 rela[i].r_offset; 41 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr + 42 ELF32_R_SYM(rela[i].r_info); 43 value = sym->st_value + rela[i].r_addend; 44 45 switch (ELF32_R_TYPE(rela[i].r_info)) { 46 47 /* 48 * Be careful! mb-gcc / mb-ld splits the relocs between the 49 * text and the reloc table. In general this means we must 50 * read the current contents of (*location), add any offset 51 * then store the result back in 52 */ 53 54 case R_MICROBLAZE_32: 55 #if __GNUC__ < 4 56 old_value = *location; 57 *location = value + old_value; 58 59 pr_debug("R_MICROBLAZE_32 (%08lx->%08lx)\n", 60 old_value, value); 61 #else 62 *location = value; 63 #endif 64 break; 65 66 case R_MICROBLAZE_64: 67 #if __GNUC__ < 4 68 /* Split relocs only required/used pre gcc4.1.1 */ 69 old_value = ((location[0] & 0x0000FFFF) << 16) | 70 (location[1] & 0x0000FFFF); 71 value += old_value; 72 #endif 73 location[0] = (location[0] & 0xFFFF0000) | 74 (value >> 16); 75 location[1] = (location[1] & 0xFFFF0000) | 76 (value & 0xFFFF); 77 #if __GNUC__ < 4 78 pr_debug("R_MICROBLAZE_64 (%08lx->%08lx)\n", 79 old_value, value); 80 #endif 81 break; 82 83 case R_MICROBLAZE_64_PCREL: 84 #if __GNUC__ < 4 85 old_value = (location[0] & 0xFFFF) << 16 | 86 (location[1] & 0xFFFF); 87 value -= old_value; 88 #endif 89 value -= (unsigned long int)(location) + 4; 90 location[0] = (location[0] & 0xFFFF0000) | 91 (value >> 16); 92 location[1] = (location[1] & 0xFFFF0000) | 93 (value & 0xFFFF); 94 pr_debug("R_MICROBLAZE_64_PCREL (%08lx)\n", 95 value); 96 break; 97 98 case R_MICROBLAZE_32_PCREL_LO: 99 pr_debug("R_MICROBLAZE_32_PCREL_LO\n"); 100 break; 101 102 case R_MICROBLAZE_64_NONE: 103 pr_debug("R_MICROBLAZE_64_NONE\n"); 104 break; 105 106 case R_MICROBLAZE_NONE: 107 pr_debug("R_MICROBLAZE_NONE\n"); 108 break; 109 110 default: 111 pr_err("module %s: Unknown relocation: %u\n", 112 module->name, 113 ELF32_R_TYPE(rela[i].r_info)); 114 return -ENOEXEC; 115 } 116 } 117 return 0; 118 } 119 120 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, 121 struct module *module) 122 { 123 flush_dcache(); 124 return 0; 125 } 126