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 #include <asm/sections.h>
25
26 #ifdef CONFIG_XIP_KERNEL
27 /*
28 * The XIP kernel text is mapped in the module area for modules and
29 * some other stuff to work without any indirect relocations.
30 * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
31 * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
32 */
33 #undef MODULES_VADDR
34 #define MODULES_VADDR (((unsigned long)_etext + ~PGDIR_MASK) & PGDIR_MASK)
35 #endif
36
37 #ifdef CONFIG_MMU
module_alloc(unsigned long size)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, MODULES_VADDR, MODULES_END);
47 if (!area)
48 return NULL;
49
50 return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
51 }
52 #else /* CONFIG_MMU */
module_alloc(unsigned long size)53 void *module_alloc(unsigned long size)
54 {
55 return size == 0 ? NULL : vmalloc(size);
56 }
57 #endif /* !CONFIG_MMU */
58
module_free(struct module * module,void * region)59 void module_free(struct module *module, void *region)
60 {
61 vfree(region);
62 }
63
module_frob_arch_sections(Elf_Ehdr * hdr,Elf_Shdr * sechdrs,char * secstrings,struct module * mod)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
apply_relocate(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relindex,struct module * module)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 case R_ARM_MOVW_ABS_NC:
136 case R_ARM_MOVT_ABS:
137 offset = *(u32 *)loc;
138 offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
139 offset = (offset ^ 0x8000) - 0x8000;
140
141 offset += sym->st_value;
142 if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
143 offset >>= 16;
144
145 *(u32 *)loc &= 0xfff0f000;
146 *(u32 *)loc |= ((offset & 0xf000) << 4) |
147 (offset & 0x0fff);
148 break;
149
150 default:
151 printk(KERN_ERR "%s: unknown relocation: %u\n",
152 module->name, ELF32_R_TYPE(rel->r_info));
153 return -ENOEXEC;
154 }
155 }
156 return 0;
157 }
158
159 int
apply_relocate_add(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * module)160 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
161 unsigned int symindex, unsigned int relsec, struct module *module)
162 {
163 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
164 module->name);
165 return -ENOEXEC;
166 }
167
168 int
module_finalize(const Elf32_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * module)169 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
170 struct module *module)
171 {
172 return 0;
173 }
174
175 void
module_arch_cleanup(struct module * mod)176 module_arch_cleanup(struct module *mod)
177 {
178 }
179