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1da177e4 LT |
1 | /* Kernel module help for x86-64 |
2 | Copyright (C) 2001 Rusty Russell. | |
3 | Copyright (C) 2002,2003 Andi Kleen, SuSE Labs. | |
4 | ||
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. | |
9 | ||
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. | |
14 | ||
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 | |
18 | */ | |
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> | |
26 | ||
27 | #include <asm/system.h> | |
28 | #include <asm/page.h> | |
29 | #include <asm/pgtable.h> | |
30 | ||
31 | #define DEBUGP(fmt...) | |
32 | ||
33 | void module_free(struct module *mod, void *module_region) | |
34 | { | |
35 | vfree(module_region); | |
36 | } | |
37 | ||
38 | void *module_alloc(unsigned long size) | |
39 | { | |
40 | struct vm_struct *area; | |
41 | ||
42 | if (!size) | |
43 | return NULL; | |
44 | size = PAGE_ALIGN(size); | |
45 | if (size > MODULES_LEN) | |
46 | return NULL; | |
47 | ||
48 | area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END); | |
49 | if (!area) | |
50 | return NULL; | |
51 | ||
52 | return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC); | |
53 | } | |
54 | ||
55 | /* We don't need anything special. */ | |
56 | int module_frob_arch_sections(Elf_Ehdr *hdr, | |
57 | Elf_Shdr *sechdrs, | |
58 | char *secstrings, | |
59 | struct module *mod) | |
60 | { | |
61 | return 0; | |
62 | } | |
63 | ||
64 | int apply_relocate_add(Elf64_Shdr *sechdrs, | |
65 | const char *strtab, | |
66 | unsigned int symindex, | |
67 | unsigned int relsec, | |
68 | struct module *me) | |
69 | { | |
70 | unsigned int i; | |
71 | Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr; | |
72 | Elf64_Sym *sym; | |
73 | void *loc; | |
74 | u64 val; | |
75 | ||
76 | DEBUGP("Applying relocate section %u to %u\n", relsec, | |
77 | sechdrs[relsec].sh_info); | |
78 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
79 | /* This is where to make the change */ | |
80 | loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
81 | + rel[i].r_offset; | |
82 | ||
83 | /* This is the symbol it is referring to. Note that all | |
84 | undefined symbols have been resolved. */ | |
85 | sym = (Elf64_Sym *)sechdrs[symindex].sh_addr | |
86 | + ELF64_R_SYM(rel[i].r_info); | |
87 | ||
88 | DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n", | |
89 | (int)ELF64_R_TYPE(rel[i].r_info), | |
90 | sym->st_value, rel[i].r_addend, (u64)loc); | |
91 | ||
92 | val = sym->st_value + rel[i].r_addend; | |
93 | ||
94 | switch (ELF64_R_TYPE(rel[i].r_info)) { | |
95 | case R_X86_64_NONE: | |
96 | break; | |
97 | case R_X86_64_64: | |
98 | *(u64 *)loc = val; | |
99 | break; | |
100 | case R_X86_64_32: | |
101 | *(u32 *)loc = val; | |
102 | if (val != *(u32 *)loc) | |
103 | goto overflow; | |
104 | break; | |
105 | case R_X86_64_32S: | |
106 | *(s32 *)loc = val; | |
107 | if ((s64)val != *(s32 *)loc) | |
108 | goto overflow; | |
109 | break; | |
110 | case R_X86_64_PC32: | |
111 | val -= (u64)loc; | |
112 | *(u32 *)loc = val; | |
113 | #if 0 | |
114 | if ((s64)val != *(s32 *)loc) | |
115 | goto overflow; | |
116 | #endif | |
117 | break; | |
118 | default: | |
119 | printk(KERN_ERR "module %s: Unknown rela relocation: %Lu\n", | |
120 | me->name, ELF64_R_TYPE(rel[i].r_info)); | |
121 | return -ENOEXEC; | |
122 | } | |
123 | } | |
124 | return 0; | |
125 | ||
126 | overflow: | |
127 | printk(KERN_ERR "overflow in relocation type %d val %Lx\n", | |
128 | (int)ELF64_R_TYPE(rel[i].r_info), val); | |
129 | printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n", | |
130 | me->name); | |
131 | return -ENOEXEC; | |
132 | } | |
133 | ||
134 | int apply_relocate(Elf_Shdr *sechdrs, | |
135 | const char *strtab, | |
136 | unsigned int symindex, | |
137 | unsigned int relsec, | |
138 | struct module *me) | |
139 | { | |
140 | printk("non add relocation not supported\n"); | |
141 | return -ENOSYS; | |
142 | } | |
143 | ||
144 | extern void apply_alternatives(void *start, void *end); | |
145 | ||
146 | int module_finalize(const Elf_Ehdr *hdr, | |
147 | const Elf_Shdr *sechdrs, | |
148 | struct module *me) | |
149 | { | |
150 | const Elf_Shdr *s; | |
151 | char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; | |
152 | ||
153 | /* look for .altinstructions to patch */ | |
154 | for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { | |
155 | void *seg; | |
156 | if (strcmp(".altinstructions", secstrings + s->sh_name)) | |
157 | continue; | |
158 | seg = (void *)s->sh_addr; | |
159 | apply_alternatives(seg, seg + s->sh_size); | |
160 | } | |
161 | return 0; | |
162 | } | |
163 | ||
164 | void module_arch_cleanup(struct module *mod) | |
165 | { | |
166 | } |