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>
27 #include <asm/system.h>
29 #include <asm/pgtable.h>
34 #define DEBUGP(fmt...)
37 void *module_alloc(unsigned long size)
39 struct vm_struct *area;
43 size = PAGE_ALIGN(size);
44 if (size > MODULES_LEN)
47 area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
51 return __vmalloc_area(area, GFP_KERNEL | __GFP_HIGHMEM,
55 /* Free memory returned from module_alloc */
56 void module_free(struct module *mod, void *module_region)
59 /* FIXME: If module_region == mod->init_region, trim exception
63 /* We don't need anything special. */
64 int module_frob_arch_sections(Elf_Ehdr *hdr,
73 int apply_relocate(Elf32_Shdr *sechdrs,
75 unsigned int symindex,
80 Elf32_Rel *rel = (void *)sechdrs[relsec].sh_addr;
84 DEBUGP("Applying relocate section %u to %u\n", relsec,
85 sechdrs[relsec].sh_info);
86 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
87 /* This is where to make the change */
88 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
90 /* This is the symbol it is referring to. Note that all
91 undefined symbols have been resolved. */
92 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
93 + ELF32_R_SYM(rel[i].r_info);
95 switch (ELF32_R_TYPE(rel[i].r_info)) {
97 /* We add the value into the location given */
98 *location += sym->st_value;
101 /* Add the value, subtract its postition */
102 *location += sym->st_value - (uint32_t)location;
105 printk(KERN_ERR "module %s: Unknown relocation: %u\n",
106 me->name, ELF32_R_TYPE(rel[i].r_info));
113 int apply_relocate_add(Elf32_Shdr *sechdrs,
115 unsigned int symindex,
119 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
124 int apply_relocate_add(Elf64_Shdr *sechdrs,
126 unsigned int symindex,
131 Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
136 DEBUGP("Applying relocate section %u to %u\n", relsec,
137 sechdrs[relsec].sh_info);
138 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
139 /* This is where to make the change */
140 loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
143 /* This is the symbol it is referring to. Note that all
144 undefined symbols have been resolved. */
145 sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
146 + ELF64_R_SYM(rel[i].r_info);
148 DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
149 (int)ELF64_R_TYPE(rel[i].r_info),
150 sym->st_value, rel[i].r_addend, (u64)loc);
152 val = sym->st_value + rel[i].r_addend;
154 switch (ELF64_R_TYPE(rel[i].r_info)) {
162 if (val != *(u32 *)loc)
167 if ((s64)val != *(s32 *)loc)
174 if ((s64)val != *(s32 *)loc)
179 printk(KERN_ERR "module %s: Unknown rela relocation: %llu\n",
180 me->name, ELF64_R_TYPE(rel[i].r_info));
187 printk(KERN_ERR "overflow in relocation type %d val %Lx\n",
188 (int)ELF64_R_TYPE(rel[i].r_info), val);
189 printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n",
194 int apply_relocate(Elf_Shdr *sechdrs,
196 unsigned int symindex,
200 printk(KERN_ERR "non add relocation not supported\n");
206 int module_finalize(const Elf_Ehdr *hdr,
207 const Elf_Shdr *sechdrs,
210 const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
212 char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
214 for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
215 if (!strcmp(".text", secstrings + s->sh_name))
217 if (!strcmp(".altinstructions", secstrings + s->sh_name))
219 if (!strcmp(".smp_locks", secstrings + s->sh_name))
221 if (!strcmp(".parainstructions", secstrings + s->sh_name))
226 /* patch .altinstructions */
227 void *aseg = (void *)alt->sh_addr;
228 apply_alternatives(aseg, aseg + alt->sh_size);
231 void *lseg = (void *)locks->sh_addr;
232 void *tseg = (void *)text->sh_addr;
233 alternatives_smp_module_add(me, me->name,
234 lseg, lseg + locks->sh_size,
235 tseg, tseg + text->sh_size);
239 void *pseg = (void *)para->sh_addr;
240 apply_paravirt(pseg, pseg + para->sh_size);
243 return module_bug_finalize(hdr, sechdrs, me);
246 void module_arch_cleanup(struct module *mod)
248 alternatives_smp_module_del(mod);
249 module_bug_cleanup(mod);