75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Module livepatch support
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*
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* Copyright (C) 2016 Jessica Yu <jeyu@redhat.com>
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*/
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include "internal.h"
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/*
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* Persist Elf information about a module. Copy the Elf header,
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* section header table, section string table, and symtab section
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* index from info to mod->klp_info.
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*/
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int copy_module_elf(struct module *mod, struct load_info *info)
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{
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unsigned int size, symndx;
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int ret;
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size = sizeof(*mod->klp_info);
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mod->klp_info = kmalloc(size, GFP_KERNEL);
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if (!mod->klp_info)
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return -ENOMEM;
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/* Elf header */
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size = sizeof(mod->klp_info->hdr);
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memcpy(&mod->klp_info->hdr, info->hdr, size);
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/* Elf section header table */
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size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
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mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
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if (!mod->klp_info->sechdrs) {
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ret = -ENOMEM;
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goto free_info;
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}
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/* Elf section name string table */
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size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
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mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
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if (!mod->klp_info->secstrings) {
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ret = -ENOMEM;
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goto free_sechdrs;
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}
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/* Elf symbol section index */
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symndx = info->index.sym;
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mod->klp_info->symndx = symndx;
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/*
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* For livepatch modules, core_kallsyms.symtab is a complete
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* copy of the original symbol table. Adjust sh_addr to point
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* to core_kallsyms.symtab since the copy of the symtab in module
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* init memory is freed at the end of do_init_module().
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*/
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mod->klp_info->sechdrs[symndx].sh_addr = (unsigned long)mod->core_kallsyms.symtab;
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return 0;
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free_sechdrs:
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kfree(mod->klp_info->sechdrs);
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free_info:
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kfree(mod->klp_info);
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return ret;
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}
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void free_module_elf(struct module *mod)
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{
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kfree(mod->klp_info->sechdrs);
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kfree(mod->klp_info->secstrings);
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kfree(mod->klp_info);
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}
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