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