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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Module livepatch support
*
* Copyright (C) 2016 Jessica Yu <jeyu@redhat.com>
*/
#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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