summaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/module.c
blob: 9203ba7d58eeaf7ce2ce05d8975c5bc9d3bd0793 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/*
 *  linux/arch/arm/kernel/module.c
 *
 *  Copyright (C) 2002 Russell King.
 *  Modified for nommu by Hyok S. Choi
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Module allocation method suggested by Andi Kleen.
 */
#include <linux/module.h>
#include <linux/moduleloader.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/string.h>

#include <asm/pgtable.h>

#ifdef CONFIG_XIP_KERNEL
/*
 * The XIP kernel text is mapped in the module area for modules and
 * some other stuff to work without any indirect relocations.
 * MODULE_START is redefined here and not in asm/memory.h to avoid
 * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
 */
extern void _etext;
#undef MODULE_START
#define MODULE_START	(((unsigned long)&_etext + ~PGDIR_MASK) & PGDIR_MASK)
#endif

#ifdef CONFIG_MMU
void *module_alloc(unsigned long size)
{
	struct vm_struct *area;

	size = PAGE_ALIGN(size);
	if (!size)
		return NULL;

	area = __get_vm_area(size, VM_ALLOC, MODULE_START, MODULE_END);
	if (!area)
		return NULL;

	return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
}
#else /* CONFIG_MMU */
void *module_alloc(unsigned long size)
{
	return size == 0 ? NULL : vmalloc(size);
}
#endif /* !CONFIG_MMU */

void module_free(struct module *module, void *region)
{
	vfree(region);
}

int module_frob_arch_sections(Elf_Ehdr *hdr,
			      Elf_Shdr *sechdrs,
			      char *secstrings,
			      struct module *mod)
{
	return 0;
}

int
apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
	       unsigned int relindex, struct module *module)
{
	Elf32_Shdr *symsec = sechdrs + symindex;
	Elf32_Shdr *relsec = sechdrs + relindex;
	Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
	Elf32_Rel *rel = (void *)relsec->sh_addr;
	unsigned int i;

	for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
		unsigned long loc;
		Elf32_Sym *sym;
		s32 offset;

		offset = ELF32_R_SYM(rel->r_info);
		if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
			printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
				module->name, relindex, i);
			return -ENOEXEC;
		}

		sym = ((Elf32_Sym *)symsec->sh_addr) + offset;

		if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
			printk(KERN_ERR "%s: out of bounds relocation, "
				"section %d reloc %d offset %d size %d\n",
				module->name, relindex, i, rel->r_offset,
				dstsec->sh_size);
			return -ENOEXEC;
		}

		loc = dstsec->sh_addr + rel->r_offset;

		switch (ELF32_R_TYPE(rel->r_info)) {
		case R_ARM_ABS32:
			*(u32 *)loc += sym->st_value;
			break;

		case R_ARM_PC24:
		case R_ARM_CALL:
		case R_ARM_JUMP24:
			offset = (*(u32 *)loc & 0x00ffffff) << 2;
			if (offset & 0x02000000)
				offset -= 0x04000000;

			offset += sym->st_value - loc;
			if (offset & 3 ||
			    offset <= (s32)0xfe000000 ||
			    offset >= (s32)0x02000000) {
				printk(KERN_ERR
				       "%s: relocation out of range, section "
				       "%d reloc %d sym '%s'\n", module->name,
				       relindex, i, strtab + sym->st_name);
				return -ENOEXEC;
			}

			offset >>= 2;

			*(u32 *)loc &= 0xff000000;
			*(u32 *)loc |= offset & 0x00ffffff;
			break;

		default:
			printk(KERN_ERR "%s: unknown relocation: %u\n",
			       module->name, ELF32_R_TYPE(rel->r_info));
			return -ENOEXEC;
		}
	}
	return 0;
}

int
apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
		   unsigned int symindex, unsigned int relsec, struct module *module)
{
	printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
	       module->name);
	return -ENOEXEC;
}

int
module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
		struct module *module)
{
	return 0;
}

void
module_arch_cleanup(struct module *mod)
{
}