Amerigo Wang | 2d5bf28 | 2009-06-03 21:46:09 -0400 | [diff] [blame] | 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 | */ |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 18 | |
| 19 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 20 | |
Amerigo Wang | 2d5bf28 | 2009-06-03 21:46:09 -0400 | [diff] [blame] | 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> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 29 | #include <linux/gfp.h> |
Jason Baron | d430d3d | 2011-03-16 17:29:47 -0400 | [diff] [blame] | 30 | #include <linux/jump_label.h> |
Amerigo Wang | 2d5bf28 | 2009-06-03 21:46:09 -0400 | [diff] [blame] | 31 | |
Amerigo Wang | 2d5bf28 | 2009-06-03 21:46:09 -0400 | [diff] [blame] | 32 | #include <asm/page.h> |
| 33 | #include <asm/pgtable.h> |
| 34 | |
| 35 | #if 0 |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 36 | #define DEBUGP(fmt, ...) \ |
| 37 | printk(KERN_DEBUG fmt, ##__VA_ARGS__) |
Amerigo Wang | 2d5bf28 | 2009-06-03 21:46:09 -0400 | [diff] [blame] | 38 | #else |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 39 | #define DEBUGP(fmt, ...) \ |
| 40 | do { \ |
| 41 | if (0) \ |
| 42 | printk(KERN_DEBUG fmt, ##__VA_ARGS__); \ |
| 43 | } while (0) |
Amerigo Wang | 2d5bf28 | 2009-06-03 21:46:09 -0400 | [diff] [blame] | 44 | #endif |
| 45 | |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 46 | void *module_alloc(unsigned long size) |
| 47 | { |
David Rientjes | d0a2126 | 2011-01-13 15:46:02 -0800 | [diff] [blame] | 48 | if (PAGE_ALIGN(size) > MODULES_LEN) |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 49 | return NULL; |
David Rientjes | d0a2126 | 2011-01-13 15:46:02 -0800 | [diff] [blame] | 50 | return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, |
| 51 | GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC, |
Jianguo Wu | 40c3baa | 2013-11-12 15:07:27 -0800 | [diff] [blame] | 52 | NUMA_NO_NODE, __builtin_return_address(0)); |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 53 | } |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 54 | |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 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 | |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 67 | DEBUGP("Applying relocate section %u to %u\n", |
| 68 | relsec, sechdrs[relsec].sh_info); |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 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: |
Geert Uytterhoeven | 2e76c28 | 2012-07-19 22:29:11 +0200 | [diff] [blame] | 84 | /* Add the value, subtract its position */ |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 85 | *location += sym->st_value - (uint32_t)location; |
| 86 | break; |
| 87 | default: |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 88 | pr_err("%s: Unknown relocation: %u\n", |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 89 | me->name, ELF32_R_TYPE(rel[i].r_info)); |
| 90 | return -ENOEXEC; |
| 91 | } |
| 92 | } |
| 93 | return 0; |
| 94 | } |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 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 | |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 108 | DEBUGP("Applying relocate section %u to %u\n", |
| 109 | relsec, sechdrs[relsec].sh_info); |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 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", |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 121 | (int)ELF64_R_TYPE(rel[i].r_info), |
| 122 | sym->st_value, rel[i].r_addend, (u64)loc); |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 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: |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 151 | pr_err("%s: Unknown rela relocation: %llu\n", |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 152 | me->name, ELF64_R_TYPE(rel[i].r_info)); |
| 153 | return -ENOEXEC; |
| 154 | } |
| 155 | } |
| 156 | return 0; |
| 157 | |
| 158 | overflow: |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 159 | pr_err("overflow in relocation type %d val %Lx\n", |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 160 | (int)ELF64_R_TYPE(rel[i].r_info), val); |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 161 | pr_err("`%s' likely not compiled with -mcmodel=kernel\n", |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 162 | me->name); |
| 163 | return -ENOEXEC; |
| 164 | } |
Amerigo Wang | 0fdc83b | 2009-06-03 21:46:19 -0400 | [diff] [blame] | 165 | #endif |
| 166 | |
Amerigo Wang | 2d5bf28 | 2009-06-03 21:46:09 -0400 | [diff] [blame] | 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 | |
Jason Baron | d9f5ab7 | 2010-09-17 11:09:22 -0400 | [diff] [blame] | 204 | /* make jump label nops */ |
| 205 | jump_label_apply_nops(me); |
| 206 | |
Linus Torvalds | 5336377 | 2010-10-05 11:29:27 -0700 | [diff] [blame] | 207 | return 0; |
Amerigo Wang | 2d5bf28 | 2009-06-03 21:46:09 -0400 | [diff] [blame] | 208 | } |
| 209 | |
| 210 | void module_arch_cleanup(struct module *mod) |
| 211 | { |
| 212 | alternatives_smp_module_del(mod); |
Amerigo Wang | 2d5bf28 | 2009-06-03 21:46:09 -0400 | [diff] [blame] | 213 | } |