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