1 /* 2 * linux/arch/arm/kernel/module.c 3 * 4 * Copyright (C) 2002 Russell King. 5 * Modified for nommu by Hyok S. Choi 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * Module allocation method suggested by Andi Kleen. 12 */ 13 #include <linux/module.h> 14 #include <linux/moduleloader.h> 15 #include <linux/kernel.h> 16 #include <linux/mm.h> 17 #include <linux/elf.h> 18 #include <linux/vmalloc.h> 19 #include <linux/slab.h> 20 #include <linux/fs.h> 21 #include <linux/string.h> 22 23 #include <asm/pgtable.h> 24 25 #ifdef CONFIG_XIP_KERNEL 26 /* 27 * The XIP kernel text is mapped in the module area for modules and 28 * some other stuff to work without any indirect relocations. 29 * MODULE_START is redefined here and not in asm/memory.h to avoid 30 * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off. 31 */ 32 extern void _etext; 33 #undef MODULE_START 34 #define MODULE_START (((unsigned long)&_etext + ~PGDIR_MASK) & PGDIR_MASK) 35 #endif 36 37 #ifdef CONFIG_MMU 38 void *module_alloc(unsigned long size) 39 { 40 struct vm_struct *area; 41 42 size = PAGE_ALIGN(size); 43 if (!size) 44 return NULL; 45 46 area = __get_vm_area(size, VM_ALLOC, MODULE_START, MODULE_END); 47 if (!area) 48 return NULL; 49 50 return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC); 51 } 52 #else /* CONFIG_MMU */ 53 void *module_alloc(unsigned long size) 54 { 55 return size == 0 ? NULL : vmalloc(size); 56 } 57 #endif /* !CONFIG_MMU */ 58 59 void module_free(struct module *module, void *region) 60 { 61 vfree(region); 62 } 63 64 int module_frob_arch_sections(Elf_Ehdr *hdr, 65 Elf_Shdr *sechdrs, 66 char *secstrings, 67 struct module *mod) 68 { 69 return 0; 70 } 71 72 int 73 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, 74 unsigned int relindex, struct module *module) 75 { 76 Elf32_Shdr *symsec = sechdrs + symindex; 77 Elf32_Shdr *relsec = sechdrs + relindex; 78 Elf32_Shdr *dstsec = sechdrs + relsec->sh_info; 79 Elf32_Rel *rel = (void *)relsec->sh_addr; 80 unsigned int i; 81 82 for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) { 83 unsigned long loc; 84 Elf32_Sym *sym; 85 s32 offset; 86 87 offset = ELF32_R_SYM(rel->r_info); 88 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) { 89 printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n", 90 module->name, relindex, i); 91 return -ENOEXEC; 92 } 93 94 sym = ((Elf32_Sym *)symsec->sh_addr) + offset; 95 96 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) { 97 printk(KERN_ERR "%s: out of bounds relocation, " 98 "section %d reloc %d offset %d size %d\n", 99 module->name, relindex, i, rel->r_offset, 100 dstsec->sh_size); 101 return -ENOEXEC; 102 } 103 104 loc = dstsec->sh_addr + rel->r_offset; 105 106 switch (ELF32_R_TYPE(rel->r_info)) { 107 case R_ARM_ABS32: 108 *(u32 *)loc += sym->st_value; 109 break; 110 111 case R_ARM_PC24: 112 case R_ARM_CALL: 113 case R_ARM_JUMP24: 114 offset = (*(u32 *)loc & 0x00ffffff) << 2; 115 if (offset & 0x02000000) 116 offset -= 0x04000000; 117 118 offset += sym->st_value - loc; 119 if (offset & 3 || 120 offset <= (s32)0xfe000000 || 121 offset >= (s32)0x02000000) { 122 printk(KERN_ERR 123 "%s: relocation out of range, section " 124 "%d reloc %d sym '%s'\n", module->name, 125 relindex, i, strtab + sym->st_name); 126 return -ENOEXEC; 127 } 128 129 offset >>= 2; 130 131 *(u32 *)loc &= 0xff000000; 132 *(u32 *)loc |= offset & 0x00ffffff; 133 break; 134 135 default: 136 printk(KERN_ERR "%s: unknown relocation: %u\n", 137 module->name, ELF32_R_TYPE(rel->r_info)); 138 return -ENOEXEC; 139 } 140 } 141 return 0; 142 } 143 144 int 145 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, 146 unsigned int symindex, unsigned int relsec, struct module *module) 147 { 148 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n", 149 module->name); 150 return -ENOEXEC; 151 } 152 153 int 154 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, 155 struct module *module) 156 { 157 return 0; 158 } 159 160 void 161 module_arch_cleanup(struct module *mod) 162 { 163 } 164