// SPDX-License-Identifier: GPL-2.0-or-later/* * Module strict rwx * * Copyright (C) 2015 Rusty Russell */ #include <linux/module.h>#include <linux/mm.h>#include <linux/vmalloc.h>#include <linux/set_memory.h>#include "internal.h" static int module_set_memory(const struct module *mod, enum mod_mem_type type,			     int (*set_memory)(unsigned long start, int num_pages)){	const struct module_memory *mod_mem = &mod->mem[type]; 	if (!mod_mem->base)		return 0; 	set_vm_flush_reset_perms(mod_mem->base);	return set_memory((unsigned long)mod_mem->base, mod_mem->size >> PAGE_SHIFT);} /* * Since some arches are moving towards PAGE_KERNEL module allocations instead * of PAGE_KERNEL_EXEC, keep module_enable_x() independent of * CONFIG_STRICT_MODULE_RWX because they are needed regardless of whether we * are strict. */int module_enable_text_rox(const struct module *mod){	for_class_mod_mem_type(type, text) {		int ret; 		if (mod->mem[type].is_rox)			continue; 		if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX))			ret = module_set_memory(mod, type, set_memory_rox);		else			ret = module_set_memory(mod, type, set_memory_x);		if (ret)			return ret;	}	return 0;} int module_enable_rodata_ro(const struct module *mod, bool after_init){	int ret; 	if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX) || !rodata_enabled)		return 0; 	ret = module_set_memory(mod, MOD_RODATA, set_memory_ro);	if (ret)		return ret;	ret = module_set_memory(mod, MOD_INIT_RODATA, set_memory_ro);	if (ret)		return ret; 	if (after_init)		return module_set_memory(mod, MOD_RO_AFTER_INIT, set_memory_ro); 	return 0;} int module_enable_data_nx(const struct module *mod){	if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))		return 0; 	for_class_mod_mem_type(type, data) {		int ret = module_set_memory(mod, type, set_memory_nx); 		if (ret)			return ret;	}	return 0;} int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,				char *secstrings, struct module *mod){	const unsigned long shf_wx = SHF_WRITE | SHF_EXECINSTR;	int i; 	if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))		return 0; 	for (i = 0; i < hdr->e_shnum; i++) {		if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {			pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",			       mod->name, secstrings + sechdrs[i].sh_name, i);			return -ENOEXEC;		}	} 	return 0;}