Linux v2.6.13-rc3
[pohmelfs.git] / arch / x86_64 / kernel / module.c
blobbac195c74bccfce81033da6d473fefea1a2cabba
1 /* Kernel module help for x86-64
2 Copyright (C) 2001 Rusty Russell.
3 Copyright (C) 2002,2003 Andi Kleen, SuSE Labs.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/moduleloader.h>
20 #include <linux/elf.h>
21 #include <linux/vmalloc.h>
22 #include <linux/fs.h>
23 #include <linux/string.h>
24 #include <linux/kernel.h>
25 #include <linux/slab.h>
27 #include <asm/system.h>
28 #include <asm/page.h>
29 #include <asm/pgtable.h>
31 #define DEBUGP(fmt...)
33 #ifndef CONFIG_UML
34 void module_free(struct module *mod, void *module_region)
36 vfree(module_region);
37 /* FIXME: If module_region == mod->init_region, trim exception
38 table entries. */
41 void *module_alloc(unsigned long size)
43 struct vm_struct *area;
45 if (!size)
46 return NULL;
47 size = PAGE_ALIGN(size);
48 if (size > MODULES_LEN)
49 return NULL;
51 area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
52 if (!area)
53 return NULL;
55 return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
57 #endif
59 /* We don't need anything special. */
60 int module_frob_arch_sections(Elf_Ehdr *hdr,
61 Elf_Shdr *sechdrs,
62 char *secstrings,
63 struct module *mod)
65 return 0;
68 int apply_relocate_add(Elf64_Shdr *sechdrs,
69 const char *strtab,
70 unsigned int symindex,
71 unsigned int relsec,
72 struct module *me)
74 unsigned int i;
75 Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
76 Elf64_Sym *sym;
77 void *loc;
78 u64 val;
80 DEBUGP("Applying relocate section %u to %u\n", relsec,
81 sechdrs[relsec].sh_info);
82 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
83 /* This is where to make the change */
84 loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
85 + rel[i].r_offset;
87 /* This is the symbol it is referring to. Note that all
88 undefined symbols have been resolved. */
89 sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
90 + ELF64_R_SYM(rel[i].r_info);
92 DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
93 (int)ELF64_R_TYPE(rel[i].r_info),
94 sym->st_value, rel[i].r_addend, (u64)loc);
96 val = sym->st_value + rel[i].r_addend;
98 switch (ELF64_R_TYPE(rel[i].r_info)) {
99 case R_X86_64_NONE:
100 break;
101 case R_X86_64_64:
102 *(u64 *)loc = val;
103 break;
104 case R_X86_64_32:
105 *(u32 *)loc = val;
106 if (val != *(u32 *)loc)
107 goto overflow;
108 break;
109 case R_X86_64_32S:
110 *(s32 *)loc = val;
111 if ((s64)val != *(s32 *)loc)
112 goto overflow;
113 break;
114 case R_X86_64_PC32:
115 val -= (u64)loc;
116 *(u32 *)loc = val;
117 #if 0
118 if ((s64)val != *(s32 *)loc)
119 goto overflow;
120 #endif
121 break;
122 default:
123 printk(KERN_ERR "module %s: Unknown rela relocation: %Lu\n",
124 me->name, ELF64_R_TYPE(rel[i].r_info));
125 return -ENOEXEC;
128 return 0;
130 overflow:
131 printk(KERN_ERR "overflow in relocation type %d val %Lx\n",
132 (int)ELF64_R_TYPE(rel[i].r_info), val);
133 printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n",
134 me->name);
135 return -ENOEXEC;
138 int apply_relocate(Elf_Shdr *sechdrs,
139 const char *strtab,
140 unsigned int symindex,
141 unsigned int relsec,
142 struct module *me)
144 printk("non add relocation not supported\n");
145 return -ENOSYS;
148 extern void apply_alternatives(void *start, void *end);
150 int module_finalize(const Elf_Ehdr *hdr,
151 const Elf_Shdr *sechdrs,
152 struct module *me)
154 const Elf_Shdr *s;
155 char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
157 /* look for .altinstructions to patch */
158 for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
159 void *seg;
160 if (strcmp(".altinstructions", secstrings + s->sh_name))
161 continue;
162 seg = (void *)s->sh_addr;
163 apply_alternatives(seg, seg + s->sh_size);
165 return 0;
168 void module_arch_cleanup(struct module *mod)