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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | /* Kernel module help for x86-64
Copyright (C) 2001 Rusty Russell.
Copyright (C) 2002,2003 Andi Kleen, SuSE Labs.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#define DEBUGP(fmt...)
#ifndef CONFIG_UML
void module_free(struct module *mod, void *module_region)
{
vfree(module_region);
/* FIXME: If module_region == mod->init_region, trim exception
table entries. */
}
void *module_alloc(unsigned long size)
{
struct vm_struct *area;
if (!size)
return NULL;
size = PAGE_ALIGN(size);
if (size > MODULES_LEN)
return NULL;
area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
if (!area)
return NULL;
return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
}
#endif
/* We don't need anything special. */
int module_frob_arch_sections(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
char *secstrings,
struct module *mod)
{
return 0;
}
int apply_relocate_add(Elf64_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
unsigned int i;
Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
Elf64_Sym *sym;
void *loc;
u64 val;
DEBUGP("Applying relocate section %u to %u\n", relsec,
sechdrs[relsec].sh_info);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* This is where to make the change */
loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rel[i].r_offset;
/* This is the symbol it is referring to. Note that all
undefined symbols have been resolved. */
sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+ ELF64_R_SYM(rel[i].r_info);
DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
(int)ELF64_R_TYPE(rel[i].r_info),
sym->st_value, rel[i].r_addend, (u64)loc);
val = sym->st_value + rel[i].r_addend;
switch (ELF64_R_TYPE(rel[i].r_info)) {
case R_X86_64_NONE:
break;
case R_X86_64_64:
*(u64 *)loc = val;
break;
case R_X86_64_32:
*(u32 *)loc = val;
if (val != *(u32 *)loc)
goto overflow;
break;
case R_X86_64_32S:
*(s32 *)loc = val;
if ((s64)val != *(s32 *)loc)
goto overflow;
break;
case R_X86_64_PC32:
val -= (u64)loc;
*(u32 *)loc = val;
#if 0
if ((s64)val != *(s32 *)loc)
goto overflow;
#endif
break;
default:
printk(KERN_ERR "module %s: Unknown rela relocation: %Lu\n",
me->name, ELF64_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
}
return 0;
overflow:
printk(KERN_ERR "overflow in relocation type %d val %Lx\n",
(int)ELF64_R_TYPE(rel[i].r_info), val);
printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n",
me->name);
return -ENOEXEC;
}
int apply_relocate(Elf_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
printk("non add relocation not supported\n");
return -ENOSYS;
}
extern void apply_alternatives(void *start, void *end);
int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *me)
{
const Elf_Shdr *s;
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
/* look for .altinstructions to patch */
for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
void *seg;
if (strcmp(".altinstructions", secstrings + s->sh_name))
continue;
seg = (void *)s->sh_addr;
apply_alternatives(seg, seg + s->sh_size);
}
return 0;
}
void module_arch_cleanup(struct module *mod)
{
}
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