1 /* 2 * linux/arch/arm/kernel/module.c 3 * 4 * Copyright (C) 2002 Russell King. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * Module allocation method suggested by Andi Kleen. 11 */ 12 #include <linux/config.h> 13 #include <linux/module.h> 14 #include <linux/moduleloader.h> 15 #include <linux/kernel.h> 16 #include <linux/elf.h> 17 #include <linux/vmalloc.h> 18 #include <linux/slab.h> 19 #include <linux/fs.h> 20 #include <linux/string.h> 21 22 #include <asm/pgtable.h> 23 24 #ifdef CONFIG_XIP_KERNEL 25 /* 26 * The XIP kernel text is mapped in the module area for modules and 27 * some other stuff to work without any indirect relocations. 28 * MODULE_START is redefined here and not in asm/memory.h to avoid 29 * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off. 30 */ 31 extern void _etext; 32 #undef MODULE_START 33 #define MODULE_START (((unsigned long)&_etext + ~PGDIR_MASK) & PGDIR_MASK) 34 #endif 35 36 void *module_alloc(unsigned long size) 37 { 38 struct vm_struct *area; 39 40 size = PAGE_ALIGN(size); 41 if (!size) 42 return NULL; 43 44 area = __get_vm_area(size, VM_ALLOC, MODULE_START, MODULE_END); 45 if (!area) 46 return NULL; 47 48 return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL); 49 } 50 51 void module_free(struct module *module, void *region) 52 { 53 vfree(region); 54 } 55 56 int module_frob_arch_sections(Elf_Ehdr *hdr, 57 Elf_Shdr *sechdrs, 58 char *secstrings, 59 struct module *mod) 60 { 61 return 0; 62 } 63 64 int 65 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, 66 unsigned int relindex, struct module *module) 67 { 68 Elf32_Shdr *symsec = sechdrs + symindex; 69 Elf32_Shdr *relsec = sechdrs + relindex; 70 Elf32_Shdr *dstsec = sechdrs + relsec->sh_info; 71 Elf32_Rel *rel = (void *)relsec->sh_addr; 72 unsigned int i; 73 74 for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) { 75 unsigned long loc; 76 Elf32_Sym *sym; 77 s32 offset; 78 79 offset = ELF32_R_SYM(rel->r_info); 80 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) { 81 printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n", 82 module->name, relindex, i); 83 return -ENOEXEC; 84 } 85 86 sym = ((Elf32_Sym *)symsec->sh_addr) + offset; 87 88 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) { 89 printk(KERN_ERR "%s: out of bounds relocation, " 90 "section %d reloc %d offset %d size %d\n", 91 module->name, relindex, i, rel->r_offset, 92 dstsec->sh_size); 93 return -ENOEXEC; 94 } 95 96 loc = dstsec->sh_addr + rel->r_offset; 97 98 switch (ELF32_R_TYPE(rel->r_info)) { 99 case R_ARM_ABS32: 100 *(u32 *)loc += sym->st_value; 101 break; 102 103 case R_ARM_PC24: 104 case R_ARM_CALL: 105 case R_ARM_JUMP24: 106 offset = (*(u32 *)loc & 0x00ffffff) << 2; 107 if (offset & 0x02000000) 108 offset -= 0x04000000; 109 110 offset += sym->st_value - loc; 111 if (offset & 3 || 112 offset <= (s32)0xfc000000 || 113 offset >= (s32)0x04000000) { 114 printk(KERN_ERR 115 "%s: relocation out of range, section " 116 "%d reloc %d sym '%s'\n", module->name, 117 relindex, i, strtab + sym->st_name); 118 return -ENOEXEC; 119 } 120 121 offset >>= 2; 122 123 *(u32 *)loc &= 0xff000000; 124 *(u32 *)loc |= offset & 0x00ffffff; 125 break; 126 127 default: 128 printk(KERN_ERR "%s: unknown relocation: %u\n", 129 module->name, ELF32_R_TYPE(rel->r_info)); 130 return -ENOEXEC; 131 } 132 } 133 return 0; 134 } 135 136 int 137 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, 138 unsigned int symindex, unsigned int relsec, struct module *module) 139 { 140 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n", 141 module->name); 142 return -ENOEXEC; 143 } 144 145 int 146 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, 147 struct module *module) 148 { 149 return 0; 150 } 151 152 void 153 module_arch_cleanup(struct module *mod) 154 { 155 } 156