75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
// 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);
|
|
}
|