/* 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) * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org> */ #include <linux/elf.h>#include <linux/compiler.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/rculist.h>#include <linux/rcupdate.h>#include <linux/mm.h> #ifndef ARCH_SHF_SMALL#define ARCH_SHF_SMALL 0#endif /* * Use highest 4 bits of sh_entsize to store the mod_mem_type of this * section. This leaves 28 bits for offset on 32-bit systems, which is * about 256 MiB (WARN_ON_ONCE if we exceed that). */ #define SH_ENTSIZE_TYPE_BITS	4#define SH_ENTSIZE_TYPE_SHIFT	(BITS_PER_LONG - SH_ENTSIZE_TYPE_BITS)#define SH_ENTSIZE_TYPE_MASK	((1UL << SH_ENTSIZE_TYPE_BITS) - 1)#define SH_ENTSIZE_OFFSET_MASK	((1UL << (BITS_PER_LONG - SH_ENTSIZE_TYPE_BITS)) - 1) /* Maximum number of characters written by module_flags() */#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) struct kernel_symbol {#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS	int value_offset;	int name_offset;	int namespace_offset;#else	unsigned long value;	const char *name;	const char *namespace;#endif}; extern struct mutex module_mutex;extern struct list_head modules; extern const struct module_attribute *const modinfo_attrs[];extern const size_t modinfo_attrs_count; /* 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 u32 __start___kcrctab[];extern const u32 __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;	bool sig_ok;#ifdef CONFIG_KALLSYMS	unsigned long mod_kallsyms_init_off;#endif#ifdef CONFIG_MODULE_DECOMPRESS#ifdef CONFIG_MODULE_STATS	unsigned long compressed_len;#endif	struct page **pages;	unsigned int max_pages;	unsigned int used_pages;#endif	struct {		unsigned int sym;		unsigned int str;		unsigned int mod;		unsigned int vers;		unsigned int info;		unsigned int pcpu;		unsigned int vers_ext_crc;		unsigned int vers_ext_name;	} index;}; enum mod_license {	NOT_GPL_ONLY,	GPL_ONLY,}; struct find_symbol_arg {	/* Input */	const char *name;	bool gplok;	bool warn; 	/* Output */	struct module *owner;	const u32 *crc;	const struct kernel_symbol *sym;	enum mod_license license;}; int mod_verify_sig(const void *mod, struct load_info *info);int try_to_force_load(struct module *mod, const char *reason);bool find_symbol(struct find_symbol_arg *fsa);struct module *find_module_all(const char *name, size_t len, bool even_unformed);int cmp_name(const void *name, const void *sym);long module_get_offset_and_type(struct module *mod, enum mod_mem_type type,				Elf_Shdr *sechdr, unsigned int section);char *module_flags(struct module *mod, char *buf, bool show_state);size_t module_flags_taint(unsigned long taints, char *buf); char *module_next_tag_pair(char *string, unsigned long *secsize); #define for_each_modinfo_entry(entry, info, name) \	for (entry = get_modinfo(info, name); entry; entry = get_next_modinfo(info, name, entry)) static inline unsigned long kernel_symbol_value(const struct kernel_symbol *sym){#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS	return (unsigned long)offset_to_ptr(&sym->value_offset);#else	return sym->value;#endif} #ifdef CONFIG_LIVEPATCHint 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} /** * enum fail_dup_mod_reason - state at which a duplicate module was detected * * @FAIL_DUP_MOD_BECOMING: the module is read properly, passes all checks but * 	we've determined that another module with the same name is already loaded * 	or being processed on our &modules list. This happens on early_mod_check() * 	right before layout_and_allocate(). The kernel would have already * 	vmalloc()'d space for the entire module through finit_module(). If * 	decompression was used two vmap() spaces were used. These failures can * 	happen when userspace has not seen the module present on the kernel and * 	tries to load the module multiple times at same time. * @FAIL_DUP_MOD_LOAD: the module has been read properly, passes all validation *	checks and the kernel determines that the module was unique and because *	of this allocated yet another private kernel copy of the module space in *	layout_and_allocate() but after this determined in add_unformed_module() *	that another module with the same name is already loaded or being processed. *	These failures should be mitigated as much as possible and are indicative *	of really fast races in loading modules. Without module decompression *	they waste twice as much vmap space. With module decompression three *	times the module's size vmap space is wasted. */enum fail_dup_mod_reason {	FAIL_DUP_MOD_BECOMING = 0,	FAIL_DUP_MOD_LOAD,}; #ifdef CONFIG_MODULE_DEBUGFSextern struct dentry *mod_debugfs_root;#endif #ifdef CONFIG_MODULE_STATS #define mod_stat_add_long(count, var) atomic_long_add(count, var)#define mod_stat_inc(name) atomic_inc(name) extern atomic_long_t total_mod_size;extern atomic_long_t total_text_size;extern atomic_long_t invalid_kread_bytes;extern atomic_long_t invalid_decompress_bytes; extern atomic_t modcount;extern atomic_t failed_kreads;extern atomic_t failed_decompress;struct mod_fail_load {	struct list_head list;	char name[MODULE_NAME_LEN];	atomic_long_t count;	unsigned long dup_fail_mask;}; int try_add_failed_module(const char *name, enum fail_dup_mod_reason reason);void mod_stat_bump_invalid(struct load_info *info, int flags);void mod_stat_bump_becoming(struct load_info *info, int flags); #else #define mod_stat_add_long(name, var)#define mod_stat_inc(name) static inline int try_add_failed_module(const char *name,					enum fail_dup_mod_reason reason){	return 0;} static inline void mod_stat_bump_invalid(struct load_info *info, int flags){} static inline void mod_stat_bump_becoming(struct load_info *info, int flags){} #endif /* CONFIG_MODULE_STATS */ #ifdef CONFIG_MODULE_DEBUG_AUTOLOAD_DUPSbool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret);void kmod_dup_request_announce(char *module_name, int ret);#elsestatic inline bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret){	return false;} static inline void kmod_dup_request_announce(char *module_name, int ret){}#endif #ifdef CONFIG_MODULE_UNLOAD_TAINT_TRACKINGstruct mod_unload_taint {	struct list_head list;	char name[MODULE_NAME_LEN];	unsigned long taints;	u64 count;}; int try_add_tainted_module(struct module *mod);void print_unloaded_tainted_modules(void);#else /* !CONFIG_MODULE_UNLOAD_TAINT_TRACKING */static inline int try_add_tainted_module(struct module *mod){	return 0;} static inline void print_unloaded_tainted_modules(void){}#endif /* CONFIG_MODULE_UNLOAD_TAINT_TRACKING */ #ifdef CONFIG_MODULE_DECOMPRESSint module_decompress(struct load_info *info, const void *buf, size_t size);void module_decompress_cleanup(struct load_info *info);#elsestatic 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 struct mod_tree_root {#ifdef CONFIG_MODULES_TREE_LOOKUP	struct latch_tree_root root;#endif	unsigned long addr_min;	unsigned long addr_max;#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC	unsigned long data_addr_min;	unsigned long data_addr_max;#endif}; extern struct mod_tree_root mod_tree; #ifdef CONFIG_MODULES_TREE_LOOKUPvoid 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, struct mod_tree_root *tree);#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 mod_tree_root *tree){	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 */ int module_enable_rodata_ro(const struct module *mod);int module_enable_rodata_ro_after_init(const struct module *mod);int module_enable_data_nx(const struct module *mod);int module_enable_text_rox(const struct module *mod);int module_enforce_rwx_sections(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,				const char *secstrings,				const struct module *mod);void module_mark_ro_after_init(const Elf_Ehdr *hdr, Elf_Shdr *sechdrs,			       const char *secstrings); #ifdef CONFIG_MODULE_SIGint 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 */ #ifdef CONFIG_DEBUG_KMEMLEAKvoid kmemleak_load_module(const struct module *mod, const struct load_info *info);#else /* !CONFIG_DEBUG_KMEMLEAK */static inline void kmemleak_load_module(const struct module *mod,					const struct load_info *info) { }#endif /* CONFIG_DEBUG_KMEMLEAK */ #ifdef CONFIG_KALLSYMSvoid init_build_id(struct module *mod, const struct load_info *info);void layout_symtab(struct module *mod, struct load_info *info);void add_kallsyms(struct module *mod, const struct load_info *info); static inline bool sect_empty(const Elf_Shdr *sect){	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;}#else /* !CONFIG_KALLSYMS */static inline void init_build_id(struct module *mod, const struct load_info *info) { }static inline void layout_symtab(struct module *mod, struct load_info *info) { }static inline void add_kallsyms(struct module *mod, const struct load_info *info) { }#endif /* CONFIG_KALLSYMS */ #ifdef CONFIG_SYSFSint mod_sysfs_setup(struct module *mod, const struct load_info *info,		    struct kernel_param *kparam, unsigned int num_params);void mod_sysfs_teardown(struct module *mod);void init_param_lock(struct module *mod);#else /* !CONFIG_SYSFS */static inline int mod_sysfs_setup(struct module *mod,			   	  const struct load_info *info,			   	  struct kernel_param *kparam,			   	  unsigned int num_params){	return 0;} static inline void mod_sysfs_teardown(struct module *mod) { }static inline void init_param_lock(struct module *mod) { }#endif /* CONFIG_SYSFS */ #ifdef CONFIG_MODVERSIONSint check_version(const struct load_info *info,		  const char *symname, struct module *mod, const u32 *crc);void module_layout(struct module *mod, struct modversion_info *ver, struct kernel_param *kp,		   struct kernel_symbol *ks, struct tracepoint * const *tp);int check_modstruct_version(const struct load_info *info, struct module *mod);int same_magic(const char *amagic, const char *bmagic, bool has_crcs);struct modversion_info_ext {	size_t remaining;	const u32 *crc;	const char *name;};void modversion_ext_start(const struct load_info *info, struct modversion_info_ext *ver);void modversion_ext_advance(struct modversion_info_ext *ver);#define for_each_modversion_info_ext(ver, info) \	for (modversion_ext_start(info, &ver); ver.remaining > 0; modversion_ext_advance(&ver))#else /* !CONFIG_MODVERSIONS */static inline int check_version(const struct load_info *info,				const char *symname,				struct module *mod,				const u32 *crc){	return 1;} static inline int check_modstruct_version(const struct load_info *info,					  struct module *mod){	return 1;} static inline int same_magic(const char *amagic, const char *bmagic, bool has_crcs){	return strcmp(amagic, bmagic) == 0;}#endif /* CONFIG_MODVERSIONS */