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 #include <linux/pgtable.h> 15 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 } 123