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