Commit | Line | Data |
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2d5bf28f AW |
1 | /* Kernel module help for x86. |
2 | Copyright (C) 2001 Rusty Russell. | |
3 | ||
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. | |
8 | ||
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. | |
13 | ||
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 | |
17 | */ | |
18 | #include <linux/moduleloader.h> | |
19 | #include <linux/elf.h> | |
20 | #include <linux/vmalloc.h> | |
21 | #include <linux/fs.h> | |
22 | #include <linux/string.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/bug.h> | |
25 | #include <linux/mm.h> | |
5a0e3ad6 | 26 | #include <linux/gfp.h> |
2d5bf28f AW |
27 | |
28 | #include <asm/system.h> | |
29 | #include <asm/page.h> | |
30 | #include <asm/pgtable.h> | |
31 | ||
32 | #if 0 | |
33 | #define DEBUGP printk | |
34 | #else | |
35 | #define DEBUGP(fmt...) | |
36 | #endif | |
37 | ||
0fdc83b9 AW |
38 | void *module_alloc(unsigned long size) |
39 | { | |
d0a21265 | 40 | if (PAGE_ALIGN(size) > MODULES_LEN) |
0fdc83b9 | 41 | return NULL; |
d0a21265 DR |
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)); | |
0fdc83b9 | 45 | } |
0fdc83b9 | 46 | |
2d5bf28f AW |
47 | /* Free memory returned from module_alloc */ |
48 | void module_free(struct module *mod, void *module_region) | |
49 | { | |
50 | vfree(module_region); | |
2d5bf28f AW |
51 | } |
52 | ||
53 | /* We don't need anything special. */ | |
54 | int module_frob_arch_sections(Elf_Ehdr *hdr, | |
55 | Elf_Shdr *sechdrs, | |
56 | char *secstrings, | |
57 | struct module *mod) | |
58 | { | |
59 | return 0; | |
60 | } | |
61 | ||
0fdc83b9 AW |
62 | #ifdef CONFIG_X86_32 |
63 | int apply_relocate(Elf32_Shdr *sechdrs, | |
64 | const char *strtab, | |
65 | unsigned int symindex, | |
66 | unsigned int relsec, | |
67 | struct module *me) | |
68 | { | |
69 | unsigned int i; | |
70 | Elf32_Rel *rel = (void *)sechdrs[relsec].sh_addr; | |
71 | Elf32_Sym *sym; | |
72 | uint32_t *location; | |
73 | ||
74 | DEBUGP("Applying relocate section %u to %u\n", relsec, | |
75 | sechdrs[relsec].sh_info); | |
76 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
77 | /* This is where to make the change */ | |
78 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
79 | + rel[i].r_offset; | |
80 | /* This is the symbol it is referring to. Note that all | |
81 | undefined symbols have been resolved. */ | |
82 | sym = (Elf32_Sym *)sechdrs[symindex].sh_addr | |
83 | + ELF32_R_SYM(rel[i].r_info); | |
84 | ||
85 | switch (ELF32_R_TYPE(rel[i].r_info)) { | |
86 | case R_386_32: | |
87 | /* We add the value into the location given */ | |
88 | *location += sym->st_value; | |
89 | break; | |
90 | case R_386_PC32: | |
91 | /* Add the value, subtract its postition */ | |
92 | *location += sym->st_value - (uint32_t)location; | |
93 | break; | |
94 | default: | |
95 | printk(KERN_ERR "module %s: Unknown relocation: %u\n", | |
96 | me->name, ELF32_R_TYPE(rel[i].r_info)); | |
97 | return -ENOEXEC; | |
98 | } | |
99 | } | |
100 | return 0; | |
101 | } | |
102 | ||
103 | int apply_relocate_add(Elf32_Shdr *sechdrs, | |
104 | const char *strtab, | |
105 | unsigned int symindex, | |
106 | unsigned int relsec, | |
107 | struct module *me) | |
108 | { | |
109 | printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n", | |
110 | me->name); | |
111 | return -ENOEXEC; | |
112 | } | |
113 | #else /*X86_64*/ | |
114 | int apply_relocate_add(Elf64_Shdr *sechdrs, | |
115 | const char *strtab, | |
116 | unsigned int symindex, | |
117 | unsigned int relsec, | |
118 | struct module *me) | |
119 | { | |
120 | unsigned int i; | |
121 | Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr; | |
122 | Elf64_Sym *sym; | |
123 | void *loc; | |
124 | u64 val; | |
125 | ||
126 | DEBUGP("Applying relocate section %u to %u\n", relsec, | |
127 | sechdrs[relsec].sh_info); | |
128 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
129 | /* This is where to make the change */ | |
130 | loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
131 | + rel[i].r_offset; | |
132 | ||
133 | /* This is the symbol it is referring to. Note that all | |
134 | undefined symbols have been resolved. */ | |
135 | sym = (Elf64_Sym *)sechdrs[symindex].sh_addr | |
136 | + ELF64_R_SYM(rel[i].r_info); | |
137 | ||
138 | DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n", | |
139 | (int)ELF64_R_TYPE(rel[i].r_info), | |
140 | sym->st_value, rel[i].r_addend, (u64)loc); | |
141 | ||
142 | val = sym->st_value + rel[i].r_addend; | |
143 | ||
144 | switch (ELF64_R_TYPE(rel[i].r_info)) { | |
145 | case R_X86_64_NONE: | |
146 | break; | |
147 | case R_X86_64_64: | |
148 | *(u64 *)loc = val; | |
149 | break; | |
150 | case R_X86_64_32: | |
151 | *(u32 *)loc = val; | |
152 | if (val != *(u32 *)loc) | |
153 | goto overflow; | |
154 | break; | |
155 | case R_X86_64_32S: | |
156 | *(s32 *)loc = val; | |
157 | if ((s64)val != *(s32 *)loc) | |
158 | goto overflow; | |
159 | break; | |
160 | case R_X86_64_PC32: | |
161 | val -= (u64)loc; | |
162 | *(u32 *)loc = val; | |
163 | #if 0 | |
164 | if ((s64)val != *(s32 *)loc) | |
165 | goto overflow; | |
166 | #endif | |
167 | break; | |
168 | default: | |
169 | printk(KERN_ERR "module %s: Unknown rela relocation: %llu\n", | |
170 | me->name, ELF64_R_TYPE(rel[i].r_info)); | |
171 | return -ENOEXEC; | |
172 | } | |
173 | } | |
174 | return 0; | |
175 | ||
176 | overflow: | |
177 | printk(KERN_ERR "overflow in relocation type %d val %Lx\n", | |
178 | (int)ELF64_R_TYPE(rel[i].r_info), val); | |
179 | printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n", | |
180 | me->name); | |
181 | return -ENOEXEC; | |
182 | } | |
183 | ||
184 | int apply_relocate(Elf_Shdr *sechdrs, | |
185 | const char *strtab, | |
186 | unsigned int symindex, | |
187 | unsigned int relsec, | |
188 | struct module *me) | |
189 | { | |
190 | printk(KERN_ERR "non add relocation not supported\n"); | |
191 | return -ENOSYS; | |
192 | } | |
193 | ||
194 | #endif | |
195 | ||
2d5bf28f AW |
196 | int module_finalize(const Elf_Ehdr *hdr, |
197 | const Elf_Shdr *sechdrs, | |
198 | struct module *me) | |
199 | { | |
200 | const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL, | |
201 | *para = NULL; | |
202 | char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; | |
203 | ||
204 | for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { | |
205 | if (!strcmp(".text", secstrings + s->sh_name)) | |
206 | text = s; | |
207 | if (!strcmp(".altinstructions", secstrings + s->sh_name)) | |
208 | alt = s; | |
209 | if (!strcmp(".smp_locks", secstrings + s->sh_name)) | |
210 | locks = s; | |
211 | if (!strcmp(".parainstructions", secstrings + s->sh_name)) | |
212 | para = s; | |
213 | } | |
214 | ||
215 | if (alt) { | |
216 | /* patch .altinstructions */ | |
217 | void *aseg = (void *)alt->sh_addr; | |
218 | apply_alternatives(aseg, aseg + alt->sh_size); | |
219 | } | |
220 | if (locks && text) { | |
221 | void *lseg = (void *)locks->sh_addr; | |
222 | void *tseg = (void *)text->sh_addr; | |
223 | alternatives_smp_module_add(me, me->name, | |
224 | lseg, lseg + locks->sh_size, | |
225 | tseg, tseg + text->sh_size); | |
226 | } | |
227 | ||
228 | if (para) { | |
229 | void *pseg = (void *)para->sh_addr; | |
230 | apply_paravirt(pseg, pseg + para->sh_size); | |
231 | } | |
232 | ||
d9f5ab7b JB |
233 | /* make jump label nops */ |
234 | jump_label_apply_nops(me); | |
235 | ||
5336377d | 236 | return 0; |
2d5bf28f AW |
237 | } |
238 | ||
239 | void module_arch_cleanup(struct module *mod) | |
240 | { | |
241 | alternatives_smp_module_del(mod); | |
2d5bf28f | 242 | } |