| 1 | |
| 2 | |
| 3 | * Module version support
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| 4 | *
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| 5 | * Copyright (C) 2008 Rusty Russell
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| 6 |
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| 7 |
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| 8 | #include <linux/module.h>
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| 9 | #include <linux/string.h>
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| 10 | #include <linux/printk.h>
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| 11 | #include "internal.h"
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| 12 |
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| 13 | int check_version(const struct load_info *info,
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| 14 | const char *symname,
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| 15 | struct module *mod,
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| 16 | const s32 *crc)
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| 17 | {
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| 18 | Elf_Shdr *sechdrs = info->sechdrs;
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| 19 | unsigned int versindex = info->index.vers;
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| 20 | unsigned int i, num_versions;
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| 21 | struct modversion_info *versions;
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| 22 |
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| 23 |
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| 24 | if (!crc)
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| 25 | return 1;
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| 26 |
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| 27 |
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| 28 | if (versindex == 0)
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| 29 | return try_to_force_load(mod, symname) == 0;
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| 30 |
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| 31 | versions = (void *)sechdrs[versindex].sh_addr;
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| 32 | num_versions = sechdrs[versindex].sh_size
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| 33 | / sizeof(struct modversion_info);
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| 34 |
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| 35 | for (i = 0; i < num_versions; i++) {
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| 36 | u32 crcval;
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| 37 |
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| 38 | if (strcmp(versions[i].name, symname) != 0)
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| 39 | continue;
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| 40 |
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| 41 | crcval = *crc;
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| 42 | if (versions[i].crc == crcval)
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| 43 | return 1;
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| 44 | pr_debug("Found checksum %X vs module %lX\n",
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| 45 | crcval, versions[i].crc);
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| 46 | goto bad_version;
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| 47 | }
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| 48 |
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| 49 |
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| 50 | pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
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| 51 | return 1;
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| 52 |
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| 53 | bad_version:
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| 54 | pr_warn("%s: disagrees about version of symbol %s\n", info->name, symname);
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| 55 | return 0;
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| 56 | }
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| 57 |
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| 58 | int check_modstruct_version(const struct load_info *info,
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| 59 | struct module *mod)
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| 60 | {
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| 61 | struct find_symbol_arg fsa = {
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| 62 | .name = "module_layout",
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| 63 | .gplok = true,
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| 64 | };
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| 65 |
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| 66 | |
| 67 | * Since this should be found in kernel (which can't be removed), no
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| 68 | * locking is necessary -- use preempt_disable() to placate lockdep.
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| 69 |
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| 70 | preempt_disable();
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| 71 | if (!find_symbol(&fsa)) {
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| 72 | preempt_enable();
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| 73 | BUG();
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| 74 | }
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| 75 | preempt_enable();
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| 76 | return check_version(info, "module_layout", mod, fsa.crc);
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| 77 | }
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| 78 |
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| 79 |
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| 80 | int same_magic(const char *amagic, const char *bmagic,
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| 81 | bool has_crcs)
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| 82 | {
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| 83 | if (has_crcs) {
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| 84 | amagic += strcspn(amagic, " ");
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| 85 | bmagic += strcspn(bmagic, " ");
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| 86 | }
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| 87 | return strcmp(amagic, bmagic) == 0;
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| 88 | }
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| 89 |
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| 90 | |
| 91 | * Generate the signature for all relevant module structures here.
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| 92 | * If these change, we don't want to try to parse the module.
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| 93 |
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| 94 | void module_layout(struct module *mod,
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| 95 | struct modversion_info *ver,
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| 96 | struct kernel_param *kp,
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| 97 | struct kernel_symbol *ks,
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| 98 | struct tracepoint * const *tp)
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| 99 | {
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| 100 | }
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| 101 | EXPORT_SYMBOL(module_layout);
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