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>
30 #include <asm/pgtable.h>
35 #define DEBUGP(fmt...)
38 void *module_alloc(unsigned long size
)
40 if (PAGE_ALIGN(size
) > MODULES_LEN
)
42 return __vmalloc_node_range(size
, 1, MODULES_VADDR
, MODULES_END
,
43 GFP_KERNEL
| __GFP_HIGHMEM
, PAGE_KERNEL_EXEC
,
44 -1, __builtin_return_address(0));
48 int apply_relocate(Elf32_Shdr
*sechdrs
,
50 unsigned int symindex
,
55 Elf32_Rel
*rel
= (void *)sechdrs
[relsec
].sh_addr
;
59 DEBUGP("Applying relocate section %u to %u\n", relsec
,
60 sechdrs
[relsec
].sh_info
);
61 for (i
= 0; i
< sechdrs
[relsec
].sh_size
/ sizeof(*rel
); i
++) {
62 /* This is where to make the change */
63 location
= (void *)sechdrs
[sechdrs
[relsec
].sh_info
].sh_addr
65 /* This is the symbol it is referring to. Note that all
66 undefined symbols have been resolved. */
67 sym
= (Elf32_Sym
*)sechdrs
[symindex
].sh_addr
68 + ELF32_R_SYM(rel
[i
].r_info
);
70 switch (ELF32_R_TYPE(rel
[i
].r_info
)) {
72 /* We add the value into the location given */
73 *location
+= sym
->st_value
;
76 /* Add the value, subtract its postition */
77 *location
+= sym
->st_value
- (uint32_t)location
;
80 printk(KERN_ERR
"module %s: Unknown relocation: %u\n",
81 me
->name
, ELF32_R_TYPE(rel
[i
].r_info
));
88 int apply_relocate_add(Elf64_Shdr
*sechdrs
,
90 unsigned int symindex
,
95 Elf64_Rela
*rel
= (void *)sechdrs
[relsec
].sh_addr
;
100 DEBUGP("Applying relocate section %u to %u\n", relsec
,
101 sechdrs
[relsec
].sh_info
);
102 for (i
= 0; i
< sechdrs
[relsec
].sh_size
/ sizeof(*rel
); i
++) {
103 /* This is where to make the change */
104 loc
= (void *)sechdrs
[sechdrs
[relsec
].sh_info
].sh_addr
107 /* This is the symbol it is referring to. Note that all
108 undefined symbols have been resolved. */
109 sym
= (Elf64_Sym
*)sechdrs
[symindex
].sh_addr
110 + ELF64_R_SYM(rel
[i
].r_info
);
112 DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
113 (int)ELF64_R_TYPE(rel
[i
].r_info
),
114 sym
->st_value
, rel
[i
].r_addend
, (u64
)loc
);
116 val
= sym
->st_value
+ rel
[i
].r_addend
;
118 switch (ELF64_R_TYPE(rel
[i
].r_info
)) {
126 if (val
!= *(u32
*)loc
)
131 if ((s64
)val
!= *(s32
*)loc
)
138 if ((s64
)val
!= *(s32
*)loc
)
143 printk(KERN_ERR
"module %s: Unknown rela relocation: %llu\n",
144 me
->name
, ELF64_R_TYPE(rel
[i
].r_info
));
151 printk(KERN_ERR
"overflow in relocation type %d val %Lx\n",
152 (int)ELF64_R_TYPE(rel
[i
].r_info
), val
);
153 printk(KERN_ERR
"`%s' likely not compiled with -mcmodel=kernel\n",
159 int module_finalize(const Elf_Ehdr
*hdr
,
160 const Elf_Shdr
*sechdrs
,
163 const Elf_Shdr
*s
, *text
= NULL
, *alt
= NULL
, *locks
= NULL
,
165 char *secstrings
= (void *)hdr
+ sechdrs
[hdr
->e_shstrndx
].sh_offset
;
167 for (s
= sechdrs
; s
< sechdrs
+ hdr
->e_shnum
; s
++) {
168 if (!strcmp(".text", secstrings
+ s
->sh_name
))
170 if (!strcmp(".altinstructions", secstrings
+ s
->sh_name
))
172 if (!strcmp(".smp_locks", secstrings
+ s
->sh_name
))
174 if (!strcmp(".parainstructions", secstrings
+ s
->sh_name
))
179 /* patch .altinstructions */
180 void *aseg
= (void *)alt
->sh_addr
;
181 apply_alternatives(aseg
, aseg
+ alt
->sh_size
);
184 void *lseg
= (void *)locks
->sh_addr
;
185 void *tseg
= (void *)text
->sh_addr
;
186 alternatives_smp_module_add(me
, me
->name
,
187 lseg
, lseg
+ locks
->sh_size
,
188 tseg
, tseg
+ text
->sh_size
);
192 void *pseg
= (void *)para
->sh_addr
;
193 apply_paravirt(pseg
, pseg
+ para
->sh_size
);
196 /* make jump label nops */
197 jump_label_apply_nops(me
);
202 void module_arch_cleanup(struct module
*mod
)
204 alternatives_smp_module_del(mod
);