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