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);