1
/* Kernel module help for x86.
2
Copyright (C) 2001 Rusty Russell.
4
This program is free software; you can redistribute it and/or modify
5
it under the terms of the GNU General Public License as published by
6
the Free Software Foundation; either version 2 of the License, or
7
(at your option) any later version.
9
This program is distributed in the hope that it will be useful,
10
but WITHOUT ANY WARRANTY; without even the implied warranty of
11
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12
GNU General Public License for more details.
14
You should have received a copy of the GNU General Public License
15
along with this program; if not, write to the Free Software
16
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
#include <linux/moduleloader.h>
19
#include <linux/elf.h>
20
#include <linux/vmalloc.h>
22
#include <linux/string.h>
23
#include <linux/kernel.h>
24
#include <linux/bug.h>
26
#include <linux/gfp.h>
27
#include <linux/jump_label.h>
29
#include <asm/system.h>
31
#include <asm/pgtable.h>
36
#define DEBUGP(fmt...)
39
void *module_alloc(unsigned long size)
41
if (PAGE_ALIGN(size) > MODULES_LEN)
43
return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
44
GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
45
-1, __builtin_return_address(0));
49
int apply_relocate(Elf32_Shdr *sechdrs,
51
unsigned int symindex,
56
Elf32_Rel *rel = (void *)sechdrs[relsec].sh_addr;
60
DEBUGP("Applying relocate section %u to %u\n", relsec,
61
sechdrs[relsec].sh_info);
62
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
63
/* This is where to make the change */
64
location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
66
/* This is the symbol it is referring to. Note that all
67
undefined symbols have been resolved. */
68
sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
69
+ ELF32_R_SYM(rel[i].r_info);
71
switch (ELF32_R_TYPE(rel[i].r_info)) {
73
/* We add the value into the location given */
74
*location += sym->st_value;
77
/* Add the value, subtract its postition */
78
*location += sym->st_value - (uint32_t)location;
81
printk(KERN_ERR "module %s: Unknown relocation: %u\n",
82
me->name, ELF32_R_TYPE(rel[i].r_info));
89
int apply_relocate_add(Elf64_Shdr *sechdrs,
91
unsigned int symindex,
96
Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
101
DEBUGP("Applying relocate section %u to %u\n", relsec,
102
sechdrs[relsec].sh_info);
103
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
104
/* This is where to make the change */
105
loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
108
/* This is the symbol it is referring to. Note that all
109
undefined symbols have been resolved. */
110
sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
111
+ ELF64_R_SYM(rel[i].r_info);
113
DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
114
(int)ELF64_R_TYPE(rel[i].r_info),
115
sym->st_value, rel[i].r_addend, (u64)loc);
117
val = sym->st_value + rel[i].r_addend;
119
switch (ELF64_R_TYPE(rel[i].r_info)) {
127
if (val != *(u32 *)loc)
132
if ((s64)val != *(s32 *)loc)
139
if ((s64)val != *(s32 *)loc)
144
printk(KERN_ERR "module %s: Unknown rela relocation: %llu\n",
145
me->name, ELF64_R_TYPE(rel[i].r_info));
152
printk(KERN_ERR "overflow in relocation type %d val %Lx\n",
153
(int)ELF64_R_TYPE(rel[i].r_info), val);
154
printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n",
160
int module_finalize(const Elf_Ehdr *hdr,
161
const Elf_Shdr *sechdrs,
164
const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
166
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
168
for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
169
if (!strcmp(".text", secstrings + s->sh_name))
171
if (!strcmp(".altinstructions", secstrings + s->sh_name))
173
if (!strcmp(".smp_locks", secstrings + s->sh_name))
175
if (!strcmp(".parainstructions", secstrings + s->sh_name))
180
/* patch .altinstructions */
181
void *aseg = (void *)alt->sh_addr;
182
apply_alternatives(aseg, aseg + alt->sh_size);
185
void *lseg = (void *)locks->sh_addr;
186
void *tseg = (void *)text->sh_addr;
187
alternatives_smp_module_add(me, me->name,
188
lseg, lseg + locks->sh_size,
189
tseg, tseg + text->sh_size);
193
void *pseg = (void *)para->sh_addr;
194
apply_paravirt(pseg, pseg + para->sh_size);
197
/* make jump label nops */
198
jump_label_apply_nops(me);
203
void module_arch_cleanup(struct module *mod)
205
alternatives_smp_module_del(mod);