linux/kernel/module/internal.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Module internals
 *
 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/elf.h>
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rculist.h>

#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif

/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG - 1))
/* Maximum number of characters written by module_flags() */
#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)

/*
 * Modules' sections will be aligned on page boundaries
 * to ensure complete separation of code and data, but
 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
 */
#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
# define debug_align(X) PAGE_ALIGN(X)
#else
# define debug_align(X) (X)
#endif

extern struct mutex module_mutex;
extern struct list_head modules;

/* Provided by the linker */
extern const struct kernel_symbol __start___ksymtab[];
extern const struct kernel_symbol __stop___ksymtab[];
extern const struct kernel_symbol __start___ksymtab_gpl[];
extern const struct kernel_symbol __stop___ksymtab_gpl[];
extern const s32 __start___kcrctab[];
extern const s32 __start___kcrctab_gpl[];

struct load_info {
	const char *name;
	/* pointer to module in temporary copy, freed at end of load_module() */
	struct module *mod;
	Elf_Ehdr *hdr;
	unsigned long len;
	Elf_Shdr *sechdrs;
	char *secstrings, *strtab;
	unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs;
	struct _ddebug *debug;
	unsigned int num_debug;
	bool sig_ok;
#ifdef CONFIG_KALLSYMS
	unsigned long mod_kallsyms_init_off;
#endif
#ifdef CONFIG_MODULE_DECOMPRESS
	struct page **pages;
	unsigned int max_pages;
	unsigned int used_pages;
#endif
	struct {
		unsigned int sym, str, mod, vers, info, pcpu;
	} index;
};

int mod_verify_sig(const void *mod, struct load_info *info);

#ifdef CONFIG_LIVEPATCH
int copy_module_elf(struct module *mod, struct load_info *info);
void free_module_elf(struct module *mod);
#else /* !CONFIG_LIVEPATCH */
static inline int copy_module_elf(struct module *mod, struct load_info *info)
{
	return 0;
}

static inline void free_module_elf(struct module *mod) { }
#endif /* CONFIG_LIVEPATCH */

static inline bool set_livepatch_module(struct module *mod)
{
#ifdef CONFIG_LIVEPATCH
	mod->klp = true;
	return true;
#else
	return false;
#endif
}

#ifdef CONFIG_MODULE_DECOMPRESS
int module_decompress(struct load_info *info, const void *buf, size_t size);
void module_decompress_cleanup(struct load_info *info);
#else
static inline int module_decompress(struct load_info *info,
				    const void *buf, size_t size)
{
	return -EOPNOTSUPP;
}

static inline void module_decompress_cleanup(struct load_info *info)
{
}
#endif

#ifdef CONFIG_MODULES_TREE_LOOKUP
struct mod_tree_root {
	struct latch_tree_root root;
	unsigned long addr_min;
	unsigned long addr_max;
};

extern struct mod_tree_root mod_tree;

void mod_tree_insert(struct module *mod);
void mod_tree_remove_init(struct module *mod);
void mod_tree_remove(struct module *mod);
struct module *mod_find(unsigned long addr);
#else /* !CONFIG_MODULES_TREE_LOOKUP */

static inline void mod_tree_insert(struct module *mod) { }
static inline void mod_tree_remove_init(struct module *mod) { }
static inline void mod_tree_remove(struct module *mod) { }
static inline struct module *mod_find(unsigned long addr)
{
	struct module *mod;

	list_for_each_entry_rcu(mod, &modules, list,
				lockdep_is_held(&module_mutex)) {
		if (within_module(addr, mod))
			return mod;
	}

	return NULL;
}
#endif /* CONFIG_MODULES_TREE_LOOKUP */

#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
void frob_text(const struct module_layout *layout, int (*set_memory)(unsigned long start,
								     int num_pages));
#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */

#ifdef CONFIG_STRICT_MODULE_RWX
void module_enable_ro(const struct module *mod, bool after_init);
void module_enable_nx(const struct module *mod);
int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
				char *secstrings, struct module *mod);

#else /* !CONFIG_STRICT_MODULE_RWX */
static inline void module_enable_nx(const struct module *mod) { }
static inline void module_enable_ro(const struct module *mod, bool after_init) {}
static inline int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
				       char *secstrings, struct module *mod)
{
	return 0;
}
#endif /* CONFIG_STRICT_MODULE_RWX */

#ifdef CONFIG_MODULE_SIG
int module_sig_check(struct load_info *info, int flags);
#else /* !CONFIG_MODULE_SIG */
static inline int module_sig_check(struct load_info *info, int flags)
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */