| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2002 Richard Henderson |
| * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. |
| */ |
| |
| #define INCLUDE_VERMAGIC |
| |
| #include <linux/export.h> |
| #include <linux/extable.h> |
| #include <linux/moduleloader.h> |
| #include <linux/module_signature.h> |
| #include <linux/trace_events.h> |
| #include <linux/init.h> |
| #include <linux/kallsyms.h> |
| #include <linux/buildid.h> |
| #include <linux/fs.h> |
| #include <linux/kernel.h> |
| #include <linux/kernel_read_file.h> |
| #include <linux/slab.h> |
| #include <linux/vmalloc.h> |
| #include <linux/elf.h> |
| #include <linux/seq_file.h> |
| #include <linux/syscalls.h> |
| #include <linux/fcntl.h> |
| #include <linux/rcupdate.h> |
| #include <linux/capability.h> |
| #include <linux/cpu.h> |
| #include <linux/moduleparam.h> |
| #include <linux/errno.h> |
| #include <linux/err.h> |
| #include <linux/vermagic.h> |
| #include <linux/notifier.h> |
| #include <linux/sched.h> |
| #include <linux/device.h> |
| #include <linux/string.h> |
| #include <linux/mutex.h> |
| #include <linux/rculist.h> |
| #include <linux/uaccess.h> |
| #include <asm/cacheflush.h> |
| #include <linux/set_memory.h> |
| #include <asm/mmu_context.h> |
| #include <linux/license.h> |
| #include <asm/sections.h> |
| #include <linux/tracepoint.h> |
| #include <linux/ftrace.h> |
| #include <linux/livepatch.h> |
| #include <linux/async.h> |
| #include <linux/percpu.h> |
| #include <linux/kmemleak.h> |
| #include <linux/jump_label.h> |
| #include <linux/pfn.h> |
| #include <linux/bsearch.h> |
| #include <linux/dynamic_debug.h> |
| #include <linux/audit.h> |
| #include <uapi/linux/module.h> |
| #include "internal.h" |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/module.h> |
| |
| /* |
| * Mutex protects: |
| * 1) List of modules (also safely readable with preempt_disable), |
| * 2) module_use links, |
| * 3) mod_tree.addr_min/mod_tree.addr_max. |
| * (delete and add uses RCU list operations). |
| */ |
| DEFINE_MUTEX(module_mutex); |
| LIST_HEAD(modules); |
| |
| /* Work queue for freeing init sections in success case */ |
| static void do_free_init(struct work_struct *w); |
| static DECLARE_WORK(init_free_wq, do_free_init); |
| static LLIST_HEAD(init_free_list); |
| |
| struct mod_tree_root mod_tree __cacheline_aligned = { |
| .addr_min = -1UL, |
| }; |
| |
| #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC |
| struct mod_tree_root mod_data_tree __cacheline_aligned = { |
| .addr_min = -1UL, |
| }; |
| #endif |
| |
| #define module_addr_min mod_tree.addr_min |
| #define module_addr_max mod_tree.addr_max |
| |
| struct symsearch { |
| const struct kernel_symbol *start, *stop; |
| const s32 *crcs; |
| enum mod_license license; |
| }; |
| |
| /* |
| * Bounds of module text, for speeding up __module_address. |
| * Protected by module_mutex. |
| */ |
| static void __mod_update_bounds(void *base, unsigned int size, struct mod_tree_root *tree) |
| { |
| unsigned long min = (unsigned long)base; |
| unsigned long max = min + size; |
| |
| if (min < tree->addr_min) |
| tree->addr_min = min; |
| if (max > tree->addr_max) |
| tree->addr_max = max; |
| } |
| |
| static void mod_update_bounds(struct module *mod) |
| { |
| __mod_update_bounds(mod->core_layout.base, mod->core_layout.size, &mod_tree); |
| if (mod->init_layout.size) |
| __mod_update_bounds(mod->init_layout.base, mod->init_layout.size, &mod_tree); |
| #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC |
| __mod_update_bounds(mod->data_layout.base, mod->data_layout.size, &mod_data_tree); |
| #endif |
| } |
| |
| /* Block module loading/unloading? */ |
| int modules_disabled; |
| core_param(nomodule, modules_disabled, bint, 0); |
| |
| /* Waiting for a module to finish initializing? */ |
| static DECLARE_WAIT_QUEUE_HEAD(module_wq); |
| |
| static BLOCKING_NOTIFIER_HEAD(module_notify_list); |
| |
| int register_module_notifier(struct notifier_block *nb) |
| { |
| return blocking_notifier_chain_register(&module_notify_list, nb); |
| } |
| EXPORT_SYMBOL(register_module_notifier); |
| |
| int unregister_module_notifier(struct notifier_block *nb) |
| { |
| return blocking_notifier_chain_unregister(&module_notify_list, nb); |
| } |
| EXPORT_SYMBOL(unregister_module_notifier); |
| |
| /* |
| * We require a truly strong try_module_get(): 0 means success. |
| * Otherwise an error is returned due to ongoing or failed |
| * initialization etc. |
| */ |
| static inline int strong_try_module_get(struct module *mod) |
| { |
| BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); |
| if (mod && mod->state == MODULE_STATE_COMING) |
| return -EBUSY; |
| if (try_module_get(mod)) |
| return 0; |
| else |
| return -ENOENT; |
| } |
| |
| static inline void add_taint_module(struct module *mod, unsigned flag, |
| enum lockdep_ok lockdep_ok) |
| { |
| add_taint(flag, lockdep_ok); |
| set_bit(flag, &mod->taints); |
| } |
| |
| /* |
| * A thread that wants to hold a reference to a module only while it |
| * is running can call this to safely exit. |
| */ |
| void __noreturn __module_put_and_kthread_exit(struct module *mod, long code) |
| { |
| module_put(mod); |
| kthread_exit(code); |
| } |
| EXPORT_SYMBOL(__module_put_and_kthread_exit); |
| |
| /* Find a module section: 0 means not found. */ |
| static unsigned int find_sec(const struct load_info *info, const char *name) |
| { |
| unsigned int i; |
| |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| Elf_Shdr *shdr = &info->sechdrs[i]; |
| /* Alloc bit cleared means "ignore it." */ |
| if ((shdr->sh_flags & SHF_ALLOC) |
| && strcmp(info->secstrings + shdr->sh_name, name) == 0) |
| return i; |
| } |
| return 0; |
| } |
| |
| /* Find a module section, or NULL. */ |
| static void *section_addr(const struct load_info *info, const char *name) |
| { |
| /* Section 0 has sh_addr 0. */ |
| return (void *)info->sechdrs[find_sec(info, name)].sh_addr; |
| } |
| |
| /* Find a module section, or NULL. Fill in number of "objects" in section. */ |
| static void *section_objs(const struct load_info *info, |
| const char *name, |
| size_t object_size, |
| unsigned int *num) |
| { |
| unsigned int sec = find_sec(info, name); |
| |
| /* Section 0 has sh_addr 0 and sh_size 0. */ |
| *num = info->sechdrs[sec].sh_size / object_size; |
| return (void *)info->sechdrs[sec].sh_addr; |
| } |
| |
| /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */ |
| static unsigned int find_any_sec(const struct load_info *info, const char *name) |
| { |
| unsigned int i; |
| |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| Elf_Shdr *shdr = &info->sechdrs[i]; |
| if (strcmp(info->secstrings + shdr->sh_name, name) == 0) |
| return i; |
| } |
| return 0; |
| } |
| |
| /* |
| * Find a module section, or NULL. Fill in number of "objects" in section. |
| * Ignores SHF_ALLOC flag. |
| */ |
| static __maybe_unused void *any_section_objs(const struct load_info *info, |
| const char *name, |
| size_t object_size, |
| unsigned int *num) |
| { |
| unsigned int sec = find_any_sec(info, name); |
| |
| /* Section 0 has sh_addr 0 and sh_size 0. */ |
| *num = info->sechdrs[sec].sh_size / object_size; |
| return (void *)info->sechdrs[sec].sh_addr; |
| } |
| |
| #ifndef CONFIG_MODVERSIONS |
| #define symversion(base, idx) NULL |
| #else |
| #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) |
| #endif |
| |
| static const char *kernel_symbol_name(const struct kernel_symbol *sym) |
| { |
| #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
| return offset_to_ptr(&sym->name_offset); |
| #else |
| return sym->name; |
| #endif |
| } |
| |
| static const char *kernel_symbol_namespace(const struct kernel_symbol *sym) |
| { |
| #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
| if (!sym->namespace_offset) |
| return NULL; |
| return offset_to_ptr(&sym->namespace_offset); |
| #else |
| return sym->namespace; |
| #endif |
| } |
| |
| int cmp_name(const void *name, const void *sym) |
| { |
| return strcmp(name, kernel_symbol_name(sym)); |
| } |
| |
| static bool find_exported_symbol_in_section(const struct symsearch *syms, |
| struct module *owner, |
| struct find_symbol_arg *fsa) |
| { |
| struct kernel_symbol *sym; |
| |
| if (!fsa->gplok && syms->license == GPL_ONLY) |
| return false; |
| |
| sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, |
| sizeof(struct kernel_symbol), cmp_name); |
| if (!sym) |
| return false; |
| |
| fsa->owner = owner; |
| fsa->crc = symversion(syms->crcs, sym - syms->start); |
| fsa->sym = sym; |
| fsa->license = syms->license; |
| |
| return true; |
| } |
| |
| /* |
| * Find an exported symbol and return it, along with, (optional) crc and |
| * (optional) module which owns it. Needs preempt disabled or module_mutex. |
| */ |
| bool find_symbol(struct find_symbol_arg *fsa) |
| { |
| static const struct symsearch arr[] = { |
| { __start___ksymtab, __stop___ksymtab, __start___kcrctab, |
| NOT_GPL_ONLY }, |
| { __start___ksymtab_gpl, __stop___ksymtab_gpl, |
| __start___kcrctab_gpl, |
| GPL_ONLY }, |
| }; |
| struct module *mod; |
| unsigned int i; |
| |
| module_assert_mutex_or_preempt(); |
| |
| for (i = 0; i < ARRAY_SIZE(arr); i++) |
| if (find_exported_symbol_in_section(&arr[i], NULL, fsa)) |
| return true; |
| |
| list_for_each_entry_rcu(mod, &modules, list, |
| lockdep_is_held(&module_mutex)) { |
| struct symsearch arr[] = { |
| { mod->syms, mod->syms + mod->num_syms, mod->crcs, |
| NOT_GPL_ONLY }, |
| { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, |
| mod->gpl_crcs, |
| GPL_ONLY }, |
| }; |
| |
| if (mod->state == MODULE_STATE_UNFORMED) |
| continue; |
| |
| for (i = 0; i < ARRAY_SIZE(arr); i++) |
| if (find_exported_symbol_in_section(&arr[i], mod, fsa)) |
| return true; |
| } |
| |
| pr_debug("Failed to find symbol %s\n", fsa->name); |
| return false; |
| } |
| |
| /* |
| * Search for module by name: must hold module_mutex (or preempt disabled |
| * for read-only access). |
| */ |
| struct module *find_module_all(const char *name, size_t len, |
| bool even_unformed) |
| { |
| struct module *mod; |
| |
| module_assert_mutex_or_preempt(); |
| |
| list_for_each_entry_rcu(mod, &modules, list, |
| lockdep_is_held(&module_mutex)) { |
| if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) |
| continue; |
| if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) |
| return mod; |
| } |
| return NULL; |
| } |
| |
| struct module *find_module(const char *name) |
| { |
| return find_module_all(name, strlen(name), false); |
| } |
| |
| #ifdef CONFIG_SMP |
| |
| static inline void __percpu *mod_percpu(struct module *mod) |
| { |
| return mod->percpu; |
| } |
| |
| static int percpu_modalloc(struct module *mod, struct load_info *info) |
| { |
| Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; |
| unsigned long align = pcpusec->sh_addralign; |
| |
| if (!pcpusec->sh_size) |
| return 0; |
| |
| if (align > PAGE_SIZE) { |
| pr_warn("%s: per-cpu alignment %li > %li\n", |
| mod->name, align, PAGE_SIZE); |
| align = PAGE_SIZE; |
| } |
| |
| mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); |
| if (!mod->percpu) { |
| pr_warn("%s: Could not allocate %lu bytes percpu data\n", |
| mod->name, (unsigned long)pcpusec->sh_size); |
| return -ENOMEM; |
| } |
| mod->percpu_size = pcpusec->sh_size; |
| return 0; |
| } |
| |
| static void percpu_modfree(struct module *mod) |
| { |
| free_percpu(mod->percpu); |
| } |
| |
| static unsigned int find_pcpusec(struct load_info *info) |
| { |
| return find_sec(info, ".data..percpu"); |
| } |
| |
| static void percpu_modcopy(struct module *mod, |
| const void *from, unsigned long size) |
| { |
| int cpu; |
| |
| for_each_possible_cpu(cpu) |
| memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); |
| } |
| |
| bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) |
| { |
| struct module *mod; |
| unsigned int cpu; |
| |
| preempt_disable(); |
| |
| list_for_each_entry_rcu(mod, &modules, list) { |
| if (mod->state == MODULE_STATE_UNFORMED) |
| continue; |
| if (!mod->percpu_size) |
| continue; |
| for_each_possible_cpu(cpu) { |
| void *start = per_cpu_ptr(mod->percpu, cpu); |
| void *va = (void *)addr; |
| |
| if (va >= start && va < start + mod->percpu_size) { |
| if (can_addr) { |
| *can_addr = (unsigned long) (va - start); |
| *can_addr += (unsigned long) |
| per_cpu_ptr(mod->percpu, |
| get_boot_cpu_id()); |
| } |
| preempt_enable(); |
| return true; |
| } |
| } |
| } |
| |
| preempt_enable(); |
| return false; |
| } |
| |
| /** |
| * is_module_percpu_address() - test whether address is from module static percpu |
| * @addr: address to test |
| * |
| * Test whether @addr belongs to module static percpu area. |
| * |
| * Return: %true if @addr is from module static percpu area |
| */ |
| bool is_module_percpu_address(unsigned long addr) |
| { |
| return __is_module_percpu_address(addr, NULL); |
| } |
| |
| #else /* ... !CONFIG_SMP */ |
| |
| static inline void __percpu *mod_percpu(struct module *mod) |
| { |
| return NULL; |
| } |
| static int percpu_modalloc(struct module *mod, struct load_info *info) |
| { |
| /* UP modules shouldn't have this section: ENOMEM isn't quite right */ |
| if (info->sechdrs[info->index.pcpu].sh_size != 0) |
| return -ENOMEM; |
| return 0; |
| } |
| static inline void percpu_modfree(struct module *mod) |
| { |
| } |
| static unsigned int find_pcpusec(struct load_info *info) |
| { |
| return 0; |
| } |
| static inline void percpu_modcopy(struct module *mod, |
| const void *from, unsigned long size) |
| { |
| /* pcpusec should be 0, and size of that section should be 0. */ |
| BUG_ON(size != 0); |
| } |
| bool is_module_percpu_address(unsigned long addr) |
| { |
| return false; |
| } |
| |
| bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) |
| { |
| return false; |
| } |
| |
| #endif /* CONFIG_SMP */ |
| |
| #define MODINFO_ATTR(field) \ |
| static void setup_modinfo_##field(struct module *mod, const char *s) \ |
| { \ |
| mod->field = kstrdup(s, GFP_KERNEL); \ |
| } \ |
| static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ |
| struct module_kobject *mk, char *buffer) \ |
| { \ |
| return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ |
| } \ |
| static int modinfo_##field##_exists(struct module *mod) \ |
| { \ |
| return mod->field != NULL; \ |
| } \ |
| static void free_modinfo_##field(struct module *mod) \ |
| { \ |
| kfree(mod->field); \ |
| mod->field = NULL; \ |
| } \ |
| static struct module_attribute modinfo_##field = { \ |
| .attr = { .name = __stringify(field), .mode = 0444 }, \ |
| .show = show_modinfo_##field, \ |
| .setup = setup_modinfo_##field, \ |
| .test = modinfo_##field##_exists, \ |
| .free = free_modinfo_##field, \ |
| }; |
| |
| MODINFO_ATTR(version); |
| MODINFO_ATTR(srcversion); |
| |
| static struct { |
| char name[MODULE_NAME_LEN + 1]; |
| char taints[MODULE_FLAGS_BUF_SIZE]; |
| } last_unloaded_module; |
| |
| #ifdef CONFIG_MODULE_UNLOAD |
| |
| EXPORT_TRACEPOINT_SYMBOL(module_get); |
| |
| /* MODULE_REF_BASE is the base reference count by kmodule loader. */ |
| #define MODULE_REF_BASE 1 |
| |
| /* Init the unload section of the module. */ |
| static int module_unload_init(struct module *mod) |
| { |
| /* |
| * Initialize reference counter to MODULE_REF_BASE. |
| * refcnt == 0 means module is going. |
| */ |
| atomic_set(&mod->refcnt, MODULE_REF_BASE); |
| |
| INIT_LIST_HEAD(&mod->source_list); |
| INIT_LIST_HEAD(&mod->target_list); |
| |
| /* Hold reference count during initialization. */ |
| atomic_inc(&mod->refcnt); |
| |
| return 0; |
| } |
| |
| /* Does a already use b? */ |
| static int already_uses(struct module *a, struct module *b) |
| { |
| struct module_use *use; |
| |
| list_for_each_entry(use, &b->source_list, source_list) { |
| if (use->source == a) { |
| pr_debug("%s uses %s!\n", a->name, b->name); |
| return 1; |
| } |
| } |
| pr_debug("%s does not use %s!\n", a->name, b->name); |
| return 0; |
| } |
| |
| /* |
| * Module a uses b |
| * - we add 'a' as a "source", 'b' as a "target" of module use |
| * - the module_use is added to the list of 'b' sources (so |
| * 'b' can walk the list to see who sourced them), and of 'a' |
| * targets (so 'a' can see what modules it targets). |
| */ |
| static int add_module_usage(struct module *a, struct module *b) |
| { |
| struct module_use *use; |
| |
| pr_debug("Allocating new usage for %s.\n", a->name); |
| use = kmalloc(sizeof(*use), GFP_ATOMIC); |
| if (!use) |
| return -ENOMEM; |
| |
| use->source = a; |
| use->target = b; |
| list_add(&use->source_list, &b->source_list); |
| list_add(&use->target_list, &a->target_list); |
| return 0; |
| } |
| |
| /* Module a uses b: caller needs module_mutex() */ |
| static int ref_module(struct module *a, struct module *b) |
| { |
| int err; |
| |
| if (b == NULL || already_uses(a, b)) |
| return 0; |
| |
| /* If module isn't available, we fail. */ |
| err = strong_try_module_get(b); |
| if (err) |
| return err; |
| |
| err = add_module_usage(a, b); |
| if (err) { |
| module_put(b); |
| return err; |
| } |
| return 0; |
| } |
| |
| /* Clear the unload stuff of the module. */ |
| static void module_unload_free(struct module *mod) |
| { |
| struct module_use *use, *tmp; |
| |
| mutex_lock(&module_mutex); |
| list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { |
| struct module *i = use->target; |
| pr_debug("%s unusing %s\n", mod->name, i->name); |
| module_put(i); |
| list_del(&use->source_list); |
| list_del(&use->target_list); |
| kfree(use); |
| } |
| mutex_unlock(&module_mutex); |
| } |
| |
| #ifdef CONFIG_MODULE_FORCE_UNLOAD |
| static inline int try_force_unload(unsigned int flags) |
| { |
| int ret = (flags & O_TRUNC); |
| if (ret) |
| add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); |
| return ret; |
| } |
| #else |
| static inline int try_force_unload(unsigned int flags) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_MODULE_FORCE_UNLOAD */ |
| |
| /* Try to release refcount of module, 0 means success. */ |
| static int try_release_module_ref(struct module *mod) |
| { |
| int ret; |
| |
| /* Try to decrement refcnt which we set at loading */ |
| ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); |
| BUG_ON(ret < 0); |
| if (ret) |
| /* Someone can put this right now, recover with checking */ |
| ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); |
| |
| return ret; |
| } |
| |
| static int try_stop_module(struct module *mod, int flags, int *forced) |
| { |
| /* If it's not unused, quit unless we're forcing. */ |
| if (try_release_module_ref(mod) != 0) { |
| *forced = try_force_unload(flags); |
| if (!(*forced)) |
| return -EWOULDBLOCK; |
| } |
| |
| /* Mark it as dying. */ |
| mod->state = MODULE_STATE_GOING; |
| |
| return 0; |
| } |
| |
| /** |
| * module_refcount() - return the refcount or -1 if unloading |
| * @mod: the module we're checking |
| * |
| * Return: |
| * -1 if the module is in the process of unloading |
| * otherwise the number of references in the kernel to the module |
| */ |
| int module_refcount(struct module *mod) |
| { |
| return atomic_read(&mod->refcnt) - MODULE_REF_BASE; |
| } |
| EXPORT_SYMBOL(module_refcount); |
| |
| /* This exists whether we can unload or not */ |
| static void free_module(struct module *mod); |
| |
| SYSCALL_DEFINE2(delete_module, const char __user *, name_user, |
| unsigned int, flags) |
| { |
| struct module *mod; |
| char name[MODULE_NAME_LEN]; |
| char buf[MODULE_FLAGS_BUF_SIZE]; |
| int ret, forced = 0; |
| |
| if (!capable(CAP_SYS_MODULE) || modules_disabled) |
| return -EPERM; |
| |
| if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) |
| return -EFAULT; |
| name[MODULE_NAME_LEN-1] = '\0'; |
| |
| audit_log_kern_module(name); |
| |
| if (mutex_lock_interruptible(&module_mutex) != 0) |
| return -EINTR; |
| |
| mod = find_module(name); |
| if (!mod) { |
| ret = -ENOENT; |
| goto out; |
| } |
| |
| if (!list_empty(&mod->source_list)) { |
| /* Other modules depend on us: get rid of them first. */ |
| ret = -EWOULDBLOCK; |
| goto out; |
| } |
| |
| /* Doing init or already dying? */ |
| if (mod->state != MODULE_STATE_LIVE) { |
| /* FIXME: if (force), slam module count damn the torpedoes */ |
| pr_debug("%s already dying\n", mod->name); |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| /* If it has an init func, it must have an exit func to unload */ |
| if (mod->init && !mod->exit) { |
| forced = try_force_unload(flags); |
| if (!forced) { |
| /* This module can't be removed */ |
| ret = -EBUSY; |
| goto out; |
| } |
| } |
| |
| ret = try_stop_module(mod, flags, &forced); |
| if (ret != 0) |
| goto out; |
| |
| mutex_unlock(&module_mutex); |
| /* Final destruction now no one is using it. */ |
| if (mod->exit != NULL) |
| mod->exit(); |
| blocking_notifier_call_chain(&module_notify_list, |
| MODULE_STATE_GOING, mod); |
| klp_module_going(mod); |
| ftrace_release_mod(mod); |
| |
| async_synchronize_full(); |
| |
| /* Store the name and taints of the last unloaded module for diagnostic purposes */ |
| strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name)); |
| strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints)); |
| |
| free_module(mod); |
| /* someone could wait for the module in add_unformed_module() */ |
| wake_up_all(&module_wq); |
| return 0; |
| out: |
| mutex_unlock(&module_mutex); |
| return ret; |
| } |
| |
| void __symbol_put(const char *symbol) |
| { |
| struct find_symbol_arg fsa = { |
| .name = symbol, |
| .gplok = true, |
| }; |
| |
| preempt_disable(); |
| BUG_ON(!find_symbol(&fsa)); |
| module_put(fsa.owner); |
| preempt_enable(); |
| } |
| EXPORT_SYMBOL(__symbol_put); |
| |
| /* Note this assumes addr is a function, which it currently always is. */ |
| void symbol_put_addr(void *addr) |
| { |
| struct module *modaddr; |
| unsigned long a = (unsigned long)dereference_function_descriptor(addr); |
| |
| if (core_kernel_text(a)) |
| return; |
| |
| /* |
| * Even though we hold a reference on the module; we still need to |
| * disable preemption in order to safely traverse the data structure. |
| */ |
| preempt_disable(); |
| modaddr = __module_text_address(a); |
| BUG_ON(!modaddr); |
| module_put(modaddr); |
| preempt_enable(); |
| } |
| EXPORT_SYMBOL_GPL(symbol_put_addr); |
| |
| static ssize_t show_refcnt(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| return sprintf(buffer, "%i\n", module_refcount(mk->mod)); |
| } |
| |
| static struct module_attribute modinfo_refcnt = |
| __ATTR(refcnt, 0444, show_refcnt, NULL); |
| |
| void __module_get(struct module *module) |
| { |
| if (module) { |
| preempt_disable(); |
| atomic_inc(&module->refcnt); |
| trace_module_get(module, _RET_IP_); |
| preempt_enable(); |
| } |
| } |
| EXPORT_SYMBOL(__module_get); |
| |
| bool try_module_get(struct module *module) |
| { |
| bool ret = true; |
| |
| if (module) { |
| preempt_disable(); |
| /* Note: here, we can fail to get a reference */ |
| if (likely(module_is_live(module) && |
| atomic_inc_not_zero(&module->refcnt) != 0)) |
| trace_module_get(module, _RET_IP_); |
| else |
| ret = false; |
| |
| preempt_enable(); |
| } |
| return ret; |
| } |
| EXPORT_SYMBOL(try_module_get); |
| |
| void module_put(struct module *module) |
| { |
| int ret; |
| |
| if (module) { |
| preempt_disable(); |
| ret = atomic_dec_if_positive(&module->refcnt); |
| WARN_ON(ret < 0); /* Failed to put refcount */ |
| trace_module_put(module, _RET_IP_); |
| preempt_enable(); |
| } |
| } |
| EXPORT_SYMBOL(module_put); |
| |
| #else /* !CONFIG_MODULE_UNLOAD */ |
| static inline void module_unload_free(struct module *mod) |
| { |
| } |
| |
| static int ref_module(struct module *a, struct module *b) |
| { |
| return strong_try_module_get(b); |
| } |
| |
| static inline int module_unload_init(struct module *mod) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_MODULE_UNLOAD */ |
| |
| size_t module_flags_taint(unsigned long taints, char *buf) |
| { |
| size_t l = 0; |
| int i; |
| |
| for (i = 0; i < TAINT_FLAGS_COUNT; i++) { |
| if (taint_flags[i].module && test_bit(i, &taints)) |
| buf[l++] = taint_flags[i].c_true; |
| } |
| |
| return l; |
| } |
| |
| static ssize_t show_initstate(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| const char *state = "unknown"; |
| |
| switch (mk->mod->state) { |
| case MODULE_STATE_LIVE: |
| state = "live"; |
| break; |
| case MODULE_STATE_COMING: |
| state = "coming"; |
| break; |
| case MODULE_STATE_GOING: |
| state = "going"; |
| break; |
| default: |
| BUG(); |
| } |
| return sprintf(buffer, "%s\n", state); |
| } |
| |
| static struct module_attribute modinfo_initstate = |
| __ATTR(initstate, 0444, show_initstate, NULL); |
| |
| static ssize_t store_uevent(struct module_attribute *mattr, |
| struct module_kobject *mk, |
| const char *buffer, size_t count) |
| { |
| int rc; |
| |
| rc = kobject_synth_uevent(&mk->kobj, buffer, count); |
| return rc ? rc : count; |
| } |
| |
| struct module_attribute module_uevent = |
| __ATTR(uevent, 0200, NULL, store_uevent); |
| |
| static ssize_t show_coresize(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| return sprintf(buffer, "%u\n", mk->mod->core_layout.size); |
| } |
| |
| static struct module_attribute modinfo_coresize = |
| __ATTR(coresize, 0444, show_coresize, NULL); |
| |
| #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC |
| static ssize_t show_datasize(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| return sprintf(buffer, "%u\n", mk->mod->data_layout.size); |
| } |
| |
| static struct module_attribute modinfo_datasize = |
| __ATTR(datasize, 0444, show_datasize, NULL); |
| #endif |
| |
| static ssize_t show_initsize(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| return sprintf(buffer, "%u\n", mk->mod->init_layout.size); |
| } |
| |
| static struct module_attribute modinfo_initsize = |
| __ATTR(initsize, 0444, show_initsize, NULL); |
| |
| static ssize_t show_taint(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| size_t l; |
| |
| l = module_flags_taint(mk->mod->taints, buffer); |
| buffer[l++] = '\n'; |
| return l; |
| } |
| |
| static struct module_attribute modinfo_taint = |
| __ATTR(taint, 0444, show_taint, NULL); |
| |
| struct module_attribute *modinfo_attrs[] = { |
| &module_uevent, |
| &modinfo_version, |
| &modinfo_srcversion, |
| &modinfo_initstate, |
| &modinfo_coresize, |
| #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC |
| &modinfo_datasize, |
| #endif |
| &modinfo_initsize, |
| &modinfo_taint, |
| #ifdef CONFIG_MODULE_UNLOAD |
| &modinfo_refcnt, |
| #endif |
| NULL, |
| }; |
| |
| size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs); |
| |
| static const char vermagic[] = VERMAGIC_STRING; |
| |
| int try_to_force_load(struct module *mod, const char *reason) |
| { |
| #ifdef CONFIG_MODULE_FORCE_LOAD |
| if (!test_taint(TAINT_FORCED_MODULE)) |
| pr_warn("%s: %s: kernel tainted.\n", mod->name, reason); |
| add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); |
| return 0; |
| #else |
| return -ENOEXEC; |
| #endif |
| } |
| |
| static char *get_modinfo(const struct load_info *info, const char *tag); |
| static char *get_next_modinfo(const struct load_info *info, const char *tag, |
| char *prev); |
| |
| static int verify_namespace_is_imported(const struct load_info *info, |
| const struct kernel_symbol *sym, |
| struct module *mod) |
| { |
| const char *namespace; |
| char *imported_namespace; |
| |
| namespace = kernel_symbol_namespace(sym); |
| if (namespace && namespace[0]) { |
| imported_namespace = get_modinfo(info, "import_ns"); |
| while (imported_namespace) { |
| if (strcmp(namespace, imported_namespace) == 0) |
| return 0; |
| imported_namespace = get_next_modinfo( |
| info, "import_ns", imported_namespace); |
| } |
| #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS |
| pr_warn( |
| #else |
| pr_err( |
| #endif |
| "%s: module uses symbol (%s) from namespace %s, but does not import it.\n", |
| mod->name, kernel_symbol_name(sym), namespace); |
| #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS |
| return -EINVAL; |
| #endif |
| } |
| return 0; |
| } |
| |
| static bool inherit_taint(struct module *mod, struct module *owner, const char *name) |
| { |
| if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) |
| return true; |
| |
| if (mod->using_gplonly_symbols) { |
| pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n", |
| mod->name, name, owner->name); |
| return false; |
| } |
| |
| if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) { |
| pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n", |
| mod->name, name, owner->name); |
| set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints); |
| } |
| return true; |
| } |
| |
| /* Resolve a symbol for this module. I.e. if we find one, record usage. */ |
| static const struct kernel_symbol *resolve_symbol(struct module *mod, |
| const struct load_info *info, |
| const char *name, |
| char ownername[]) |
| { |
| struct find_symbol_arg fsa = { |
| .name = name, |
| .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), |
| .warn = true, |
| }; |
| int err; |
| |
| /* |
| * The module_mutex should not be a heavily contended lock; |
| * if we get the occasional sleep here, we'll go an extra iteration |
| * in the wait_event_interruptible(), which is harmless. |
| */ |
| sched_annotate_sleep(); |
| mutex_lock(&module_mutex); |
| if (!find_symbol(&fsa)) |
| goto unlock; |
| |
| if (fsa.license == GPL_ONLY) |
| mod->using_gplonly_symbols = true; |
| |
| if (!inherit_taint(mod, fsa.owner, name)) { |
| fsa.sym = NULL; |
| goto getname; |
| } |
| |
| if (!check_version(info, name, mod, fsa.crc)) { |
| fsa.sym = ERR_PTR(-EINVAL); |
| goto getname; |
| } |
| |
| err = verify_namespace_is_imported(info, fsa.sym, mod); |
| if (err) { |
| fsa.sym = ERR_PTR(err); |
| goto getname; |
| } |
| |
| err = ref_module(mod, fsa.owner); |
| if (err) { |
| fsa.sym = ERR_PTR(err); |
| goto getname; |
| } |
| |
| getname: |
| /* We must make copy under the lock if we failed to get ref. */ |
| strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN); |
| unlock: |
| mutex_unlock(&module_mutex); |
| return fsa.sym; |
| } |
| |
| static const struct kernel_symbol * |
| resolve_symbol_wait(struct module *mod, |
| const struct load_info *info, |
| const char *name) |
| { |
| const struct kernel_symbol *ksym; |
| char owner[MODULE_NAME_LEN]; |
| |
| if (wait_event_interruptible_timeout(module_wq, |
| !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) |
| || PTR_ERR(ksym) != -EBUSY, |
| 30 * HZ) <= 0) { |
| pr_warn("%s: gave up waiting for init of module %s.\n", |
| mod->name, owner); |
| } |
| return ksym; |
| } |
| |
| void __weak module_memfree(void *module_region) |
| { |
| /* |
| * This memory may be RO, and freeing RO memory in an interrupt is not |
| * supported by vmalloc. |
| */ |
| WARN_ON(in_interrupt()); |
| vfree(module_region); |
| } |
| |
| void __weak module_arch_cleanup(struct module *mod) |
| { |
| } |
| |
| void __weak module_arch_freeing_init(struct module *mod) |
| { |
| } |
| |
| static void cfi_cleanup(struct module *mod); |
| |
| /* Free a module, remove from lists, etc. */ |
| static void free_module(struct module *mod) |
| { |
| trace_module_free(mod); |
| |
| mod_sysfs_teardown(mod); |
| |
| /* |
| * We leave it in list to prevent duplicate loads, but make sure |
| * that noone uses it while it's being deconstructed. |
| */ |
| mutex_lock(&module_mutex); |
| mod->state = MODULE_STATE_UNFORMED; |
| mutex_unlock(&module_mutex); |
| |
| /* Remove dynamic debug info */ |
| ddebug_remove_module(mod->name); |
| |
| /* Arch-specific cleanup. */ |
| module_arch_cleanup(mod); |
| |
| /* Module unload stuff */ |
| module_unload_free(mod); |
| |
| /* Free any allocated parameters. */ |
| destroy_params(mod->kp, mod->num_kp); |
| |
| if (is_livepatch_module(mod)) |
| free_module_elf(mod); |
| |
| /* Now we can delete it from the lists */ |
| mutex_lock(&module_mutex); |
| /* Unlink carefully: kallsyms could be walking list. */ |
| list_del_rcu(&mod->list); |
| mod_tree_remove(mod); |
| /* Remove this module from bug list, this uses list_del_rcu */ |
| module_bug_cleanup(mod); |
| /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ |
| synchronize_rcu(); |
| if (try_add_tainted_module(mod)) |
| pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n", |
| mod->name); |
| mutex_unlock(&module_mutex); |
| |
| /* Clean up CFI for the module. */ |
| cfi_cleanup(mod); |
| |
| /* This may be empty, but that's OK */ |
| module_arch_freeing_init(mod); |
| module_memfree(mod->init_layout.base); |
| kfree(mod->args); |
| percpu_modfree(mod); |
| |
| /* Free lock-classes; relies on the preceding sync_rcu(). */ |
| lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size); |
| |
| /* Finally, free the core (containing the module structure) */ |
| module_memfree(mod->core_layout.base); |
| #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC |
| vfree(mod->data_layout.base); |
| #endif |
| } |
| |
| void *__symbol_get(const char *symbol) |
| { |
| struct find_symbol_arg fsa = { |
| .name = symbol, |
| .gplok = true, |
| .warn = true, |
| }; |
| |
| preempt_disable(); |
| if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) { |
| preempt_enable(); |
| return NULL; |
| } |
| preempt_enable(); |
| return (void *)kernel_symbol_value(fsa.sym); |
| } |
| EXPORT_SYMBOL_GPL(__symbol_get); |
| |
| /* |
| * Ensure that an exported symbol [global namespace] does not already exist |
| * in the kernel or in some other module's exported symbol table. |
| * |
| * You must hold the module_mutex. |
| */ |
| static int verify_exported_symbols(struct module *mod) |
| { |
| unsigned int i; |
| const struct kernel_symbol *s; |
| struct { |
| const struct kernel_symbol *sym; |
| unsigned int num; |
| } arr[] = { |
| { mod->syms, mod->num_syms }, |
| { mod->gpl_syms, mod->num_gpl_syms }, |
| }; |
| |
| for (i = 0; i < ARRAY_SIZE(arr); i++) { |
| for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { |
| struct find_symbol_arg fsa = { |
| .name = kernel_symbol_name(s), |
| .gplok = true, |
| }; |
| if (find_symbol(&fsa)) { |
| pr_err("%s: exports duplicate symbol %s" |
| " (owned by %s)\n", |
| mod->name, kernel_symbol_name(s), |
| module_name(fsa.owner)); |
| return -ENOEXEC; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| static bool ignore_undef_symbol(Elf_Half emachine, const char *name) |
| { |
| /* |
| * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as |
| * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64. |
| * i386 has a similar problem but may not deserve a fix. |
| * |
| * If we ever have to ignore many symbols, consider refactoring the code to |
| * only warn if referenced by a relocation. |
| */ |
| if (emachine == EM_386 || emachine == EM_X86_64) |
| return !strcmp(name, "_GLOBAL_OFFSET_TABLE_"); |
| return false; |
| } |
| |
| /* Change all symbols so that st_value encodes the pointer directly. */ |
| static int simplify_symbols(struct module *mod, const struct load_info *info) |
| { |
| Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; |
| Elf_Sym *sym = (void *)symsec->sh_addr; |
| unsigned long secbase; |
| unsigned int i; |
| int ret = 0; |
| const struct kernel_symbol *ksym; |
| |
| for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { |
| const char *name = info->strtab + sym[i].st_name; |
| |
| switch (sym[i].st_shndx) { |
| case SHN_COMMON: |
| /* Ignore common symbols */ |
| if (!strncmp(name, "__gnu_lto", 9)) |
| break; |
| |
| /* |
| * We compiled with -fno-common. These are not |
| * supposed to happen. |
| */ |
| pr_debug("Common symbol: %s\n", name); |
| pr_warn("%s: please compile with -fno-common\n", |
| mod->name); |
| ret = -ENOEXEC; |
| break; |
| |
| case SHN_ABS: |
| /* Don't need to do anything */ |
| pr_debug("Absolute symbol: 0x%08lx\n", |
| (long)sym[i].st_value); |
| break; |
| |
| case SHN_LIVEPATCH: |
| /* Livepatch symbols are resolved by livepatch */ |
| break; |
| |
| case SHN_UNDEF: |
| ksym = resolve_symbol_wait(mod, info, name); |
| /* Ok if resolved. */ |
| if (ksym && !IS_ERR(ksym)) { |
| sym[i].st_value = kernel_symbol_value(ksym); |
| break; |
| } |
| |
| /* Ok if weak or ignored. */ |
| if (!ksym && |
| (ELF_ST_BIND(sym[i].st_info) == STB_WEAK || |
| ignore_undef_symbol(info->hdr->e_machine, name))) |
| break; |
| |
| ret = PTR_ERR(ksym) ?: -ENOENT; |
| pr_warn("%s: Unknown symbol %s (err %d)\n", |
| mod->name, name, ret); |
| break; |
| |
| default: |
| /* Divert to percpu allocation if a percpu var. */ |
| if (sym[i].st_shndx == info->index.pcpu) |
| secbase = (unsigned long)mod_percpu(mod); |
| else |
| secbase = info->sechdrs[sym[i].st_shndx].sh_addr; |
| sym[i].st_value += secbase; |
| break; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int apply_relocations(struct module *mod, const struct load_info *info) |
| { |
| unsigned int i; |
| int err = 0; |
| |
| /* Now do relocations. */ |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| unsigned int infosec = info->sechdrs[i].sh_info; |
| |
| /* Not a valid relocation section? */ |
| if (infosec >= info->hdr->e_shnum) |
| continue; |
| |
| /* Don't bother with non-allocated sections */ |
| if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) |
| continue; |
| |
| if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) |
| err = klp_apply_section_relocs(mod, info->sechdrs, |
| info->secstrings, |
| info->strtab, |
| info->index.sym, i, |
| NULL); |
| else if (info->sechdrs[i].sh_type == SHT_REL) |
| err = apply_relocate(info->sechdrs, info->strtab, |
| info->index.sym, i, mod); |
| else if (info->sechdrs[i].sh_type == SHT_RELA) |
| err = apply_relocate_add(info->sechdrs, info->strtab, |
| info->index.sym, i, mod); |
| if (err < 0) |
| break; |
| } |
| return err; |
| } |
| |
| /* Additional bytes needed by arch in front of individual sections */ |
| unsigned int __weak arch_mod_section_prepend(struct module *mod, |
| unsigned int section) |
| { |
| /* default implementation just returns zero */ |
| return 0; |
| } |
| |
| /* Update size with this section: return offset. */ |
| long module_get_offset(struct module *mod, unsigned int *size, |
| Elf_Shdr *sechdr, unsigned int section) |
| { |
| long ret; |
| |
| *size += arch_mod_section_prepend(mod, section); |
| ret = ALIGN(*size, sechdr->sh_addralign ?: 1); |
| *size = ret + sechdr->sh_size; |
| return ret; |
| } |
| |
| static bool module_init_layout_section(const char *sname) |
| { |
| #ifndef CONFIG_MODULE_UNLOAD |
| if (module_exit_section(sname)) |
| return true; |
| #endif |
| return module_init_section(sname); |
| } |
| |
| /* |
| * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld |
| * might -- code, read-only data, read-write data, small data. Tally |
| * sizes, and place the offsets into sh_entsize fields: high bit means it |
| * belongs in init. |
| */ |
| static void layout_sections(struct module *mod, struct load_info *info) |
| { |
| static unsigned long const masks[][2] = { |
| /* |
| * NOTE: all executable code must be the first section |
| * in this array; otherwise modify the text_size |
| * finder in the two loops below |
| */ |
| { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, |
| { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, |
| { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, |
| { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, |
| { ARCH_SHF_SMALL | SHF_ALLOC, 0 } |
| }; |
| unsigned int m, i; |
| |
| for (i = 0; i < info->hdr->e_shnum; i++) |
| info->sechdrs[i].sh_entsize = ~0UL; |
| |
| pr_debug("Core section allocation order:\n"); |
| for (m = 0; m < ARRAY_SIZE(masks); ++m) { |
| for (i = 0; i < info->hdr->e_shnum; ++i) { |
| Elf_Shdr *s = &info->sechdrs[i]; |
| const char *sname = info->secstrings + s->sh_name; |
| unsigned int *sizep; |
| |
| if ((s->sh_flags & masks[m][0]) != masks[m][0] |
| || (s->sh_flags & masks[m][1]) |
| || s->sh_entsize != ~0UL |
| || module_init_layout_section(sname)) |
| continue; |
| sizep = m ? &mod->data_layout.size : &mod->core_layout.size; |
| s->sh_entsize = module_get_offset(mod, sizep, s, i); |
| pr_debug("\t%s\n", sname); |
| } |
| switch (m) { |
| case 0: /* executable */ |
| mod->core_layout.size = strict_align(mod->core_layout.size); |
| mod->core_layout.text_size = mod->core_layout.size; |
| break; |
| case 1: /* RO: text and ro-data */ |
| mod->data_layout.size = strict_align(mod->data_layout.size); |
| mod->data_layout.ro_size = mod->data_layout.size; |
| break; |
| case 2: /* RO after init */ |
| mod->data_layout.size = strict_align(mod->data_layout.size); |
| mod->data_layout.ro_after_init_size = mod->data_layout.size; |
| break; |
| case 4: /* whole core */ |
| mod->data_layout.size = strict_align(mod->data_layout.size); |
| break; |
| } |
| } |
| |
| pr_debug("Init section allocation order:\n"); |
| for (m = 0; m < ARRAY_SIZE(masks); ++m) { |
| for (i = 0; i < info->hdr->e_shnum; ++i) { |
| Elf_Shdr *s = &info->sechdrs[i]; |
| const char *sname = info->secstrings + s->sh_name; |
| |
| if ((s->sh_flags & masks[m][0]) != masks[m][0] |
| || (s->sh_flags & masks[m][1]) |
| || s->sh_entsize != ~0UL |
| || !module_init_layout_section(sname)) |
| continue; |
| s->sh_entsize = (module_get_offset(mod, &mod->init_layout.size, s, i) |
| | INIT_OFFSET_MASK); |
| pr_debug("\t%s\n", sname); |
| } |
| switch (m) { |
| case 0: /* executable */ |
| mod->init_layout.size = strict_align(mod->init_layout.size); |
| mod->init_layout.text_size = mod->init_layout.size; |
| break; |
| case 1: /* RO: text and ro-data */ |
| mod->init_layout.size = strict_align(mod->init_layout.size); |
| mod->init_layout.ro_size = mod->init_layout.size; |
| break; |
| case 2: |
| /* |
| * RO after init doesn't apply to init_layout (only |
| * core_layout), so it just takes the value of ro_size. |
| */ |
| mod->init_layout.ro_after_init_size = mod->init_layout.ro_size; |
| break; |
| case 4: /* whole init */ |
| mod->init_layout.size = strict_align(mod->init_layout.size); |
| break; |
| } |
| } |
| } |
| |
| static void set_license(struct module *mod, const char *license) |
| { |
| if (!license) |
| license = "unspecified"; |
| |
| if (!license_is_gpl_compatible(license)) { |
| if (!test_taint(TAINT_PROPRIETARY_MODULE)) |
| pr_warn("%s: module license '%s' taints kernel.\n", |
| mod->name, license); |
| add_taint_module(mod, TAINT_PROPRIETARY_MODULE, |
| LOCKDEP_NOW_UNRELIABLE); |
| } |
| } |
| |
| /* Parse tag=value strings from .modinfo section */ |
| static char *next_string(char *string, unsigned long *secsize) |
| { |
| /* Skip non-zero chars */ |
| while (string[0]) { |
| string++; |
| if ((*secsize)-- <= 1) |
| return NULL; |
| } |
| |
| /* Skip any zero padding. */ |
| while (!string[0]) { |
| string++; |
| if ((*secsize)-- <= 1) |
| return NULL; |
| } |
| return string; |
| } |
| |
| static char *get_next_modinfo(const struct load_info *info, const char *tag, |
| char *prev) |
| { |
| char *p; |
| unsigned int taglen = strlen(tag); |
| Elf_Shdr *infosec = &info->sechdrs[info->index.info]; |
| unsigned long size = infosec->sh_size; |
| |
| /* |
| * get_modinfo() calls made before rewrite_section_headers() |
| * must use sh_offset, as sh_addr isn't set! |
| */ |
| char *modinfo = (char *)info->hdr + infosec->sh_offset; |
| |
| if (prev) { |
| size -= prev - modinfo; |
| modinfo = next_string(prev, &size); |
| } |
| |
| for (p = modinfo; p; p = next_string(p, &size)) { |
| if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') |
| return p + taglen + 1; |
| } |
| return NULL; |
| } |
| |
| static char *get_modinfo(const struct load_info *info, const char *tag) |
| { |
| return get_next_modinfo(info, tag, NULL); |
| } |
| |
| static void setup_modinfo(struct module *mod, struct load_info *info) |
| { |
| struct module_attribute *attr; |
| int i; |
| |
| for (i = 0; (attr = modinfo_attrs[i]); i++) { |
| if (attr->setup) |
| attr->setup(mod, get_modinfo(info, attr->attr.name)); |
| } |
| } |
| |
| static void free_modinfo(struct module *mod) |
| { |
| struct module_attribute *attr; |
| int i; |
| |
| for (i = 0; (attr = modinfo_attrs[i]); i++) { |
| if (attr->free) |
| attr->free(mod); |
| } |
| } |
| |
| static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num) |
| { |
| if (!debug) |
| return; |
| ddebug_add_module(debug, num, mod->name); |
| } |
| |
| static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) |
| { |
| if (debug) |
| ddebug_remove_module(mod->name); |
| } |
| |
| void * __weak module_alloc(unsigned long size) |
| { |
| return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, |
| GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, |
| NUMA_NO_NODE, __builtin_return_address(0)); |
| } |
| |
| bool __weak module_init_section(const char *name) |
| { |
| return strstarts(name, ".init"); |
| } |
| |
| bool __weak module_exit_section(const char *name) |
| { |
| return strstarts(name, ".exit"); |
| } |
| |
| static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr) |
| { |
| #if defined(CONFIG_64BIT) |
| unsigned long long secend; |
| #else |
| unsigned long secend; |
| #endif |
| |
| /* |
| * Check for both overflow and offset/size being |
| * too large. |
| */ |
| secend = shdr->sh_offset + shdr->sh_size; |
| if (secend < shdr->sh_offset || secend > info->len) |
| return -ENOEXEC; |
| |
| return 0; |
| } |
| |
| /* |
| * Sanity checks against invalid binaries, wrong arch, weird elf version. |
| * |
| * Also do basic validity checks against section offsets and sizes, the |
| * section name string table, and the indices used for it (sh_name). |
| */ |
| static int elf_validity_check(struct load_info *info) |
| { |
| unsigned int i; |
| Elf_Shdr *shdr, *strhdr; |
| int err; |
| |
| if (info->len < sizeof(*(info->hdr))) { |
| pr_err("Invalid ELF header len %lu\n", info->len); |
| goto no_exec; |
| } |
| |
| if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) { |
| pr_err("Invalid ELF header magic: != %s\n", ELFMAG); |
| goto no_exec; |
| } |
| if (info->hdr->e_type != ET_REL) { |
| pr_err("Invalid ELF header type: %u != %u\n", |
| info->hdr->e_type, ET_REL); |
| goto no_exec; |
| } |
| if (!elf_check_arch(info->hdr)) { |
| pr_err("Invalid architecture in ELF header: %u\n", |
| info->hdr->e_machine); |
| goto no_exec; |
| } |
| if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) { |
| pr_err("Invalid ELF section header size\n"); |
| goto no_exec; |
| } |
| |
| /* |
| * e_shnum is 16 bits, and sizeof(Elf_Shdr) is |
| * known and small. So e_shnum * sizeof(Elf_Shdr) |
| * will not overflow unsigned long on any platform. |
| */ |
| if (info->hdr->e_shoff >= info->len |
| || (info->hdr->e_shnum * sizeof(Elf_Shdr) > |
| info->len - info->hdr->e_shoff)) { |
| pr_err("Invalid ELF section header overflow\n"); |
| goto no_exec; |
| } |
| |
| info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; |
| |
| /* |
| * Verify if the section name table index is valid. |
| */ |
| if (info->hdr->e_shstrndx == SHN_UNDEF |
| || info->hdr->e_shstrndx >= info->hdr->e_shnum) { |
| pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n", |
| info->hdr->e_shstrndx, info->hdr->e_shstrndx, |
| info->hdr->e_shnum); |
| goto no_exec; |
| } |
| |
| strhdr = &info->sechdrs[info->hdr->e_shstrndx]; |
| err = validate_section_offset(info, strhdr); |
| if (err < 0) { |
| pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type); |
| return err; |
| } |
| |
| /* |
| * The section name table must be NUL-terminated, as required |
| * by the spec. This makes strcmp and pr_* calls that access |
| * strings in the section safe. |
| */ |
| info->secstrings = (void *)info->hdr + strhdr->sh_offset; |
| if (strhdr->sh_size == 0) { |
| pr_err("empty section name table\n"); |
| goto no_exec; |
| } |
| if (info->secstrings[strhdr->sh_size - 1] != '\0') { |
| pr_err("ELF Spec violation: section name table isn't null terminated\n"); |
| goto no_exec; |
| } |
| |
| /* |
| * The code assumes that section 0 has a length of zero and |
| * an addr of zero, so check for it. |
| */ |
| if (info->sechdrs[0].sh_type != SHT_NULL |
| || info->sechdrs[0].sh_size != 0 |
| || info->sechdrs[0].sh_addr != 0) { |
| pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n", |
| info->sechdrs[0].sh_type); |
| goto no_exec; |
| } |
| |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| shdr = &info->sechdrs[i]; |
| switch (shdr->sh_type) { |
| case SHT_NULL: |
| case SHT_NOBITS: |
| continue; |
| case SHT_SYMTAB: |
| if (shdr->sh_link == SHN_UNDEF |
| || shdr->sh_link >= info->hdr->e_shnum) { |
| pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n", |
| shdr->sh_link, shdr->sh_link, |
| info->hdr->e_shnum); |
| goto no_exec; |
| } |
| fallthrough; |
| default: |
| err = validate_section_offset(info, shdr); |
| if (err < 0) { |
| pr_err("Invalid ELF section in module (section %u type %u)\n", |
| i, shdr->sh_type); |
| return err; |
| } |
| |
| if (shdr->sh_flags & SHF_ALLOC) { |
| if (shdr->sh_name >= strhdr->sh_size) { |
| pr_err("Invalid ELF section name in module (section %u type %u)\n", |
| i, shdr->sh_type); |
| return -ENOEXEC; |
| } |
| } |
| break; |
| } |
| } |
| |
| return 0; |
| |
| no_exec: |
| return -ENOEXEC; |
| } |
| |
| #define COPY_CHUNK_SIZE (16*PAGE_SIZE) |
| |
| static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len) |
| { |
| do { |
| unsigned long n = min(len, COPY_CHUNK_SIZE); |
| |
| if (copy_from_user(dst, usrc, n) != 0) |
| return -EFAULT; |
| cond_resched(); |
| dst += n; |
| usrc += n; |
| len -= n; |
| } while (len); |
| return 0; |
| } |
| |
| static int check_modinfo_livepatch(struct module *mod, struct load_info *info) |
| { |
| if (!get_modinfo(info, "livepatch")) |
| /* Nothing more to do */ |
| return 0; |
| |
| if (set_livepatch_module(mod)) { |
| add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); |
| pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n", |
| mod->name); |
| return 0; |
| } |
| |
| pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", |
| mod->name); |
| return -ENOEXEC; |
| } |
| |
| static void check_modinfo_retpoline(struct module *mod, struct load_info *info) |
| { |
| if (retpoline_module_ok(get_modinfo(info, "retpoline"))) |
| return; |
| |
| pr_warn("%s: loading module not compiled with retpoline compiler.\n", |
| mod->name); |
| } |
| |
| /* Sets info->hdr and info->len. */ |
| static int copy_module_from_user(const void __user *umod, unsigned long len, |
| struct load_info *info) |
| { |
| int err; |
| |
| info->len = len; |
| if (info->len < sizeof(*(info->hdr))) |
| return -ENOEXEC; |
| |
| err = security_kernel_load_data(LOADING_MODULE, true); |
| if (err) |
| return err; |
| |
| /* Suck in entire file: we'll want most of it. */ |
| info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN); |
| if (!info->hdr) |
| return -ENOMEM; |
| |
| if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { |
| err = -EFAULT; |
| goto out; |
| } |
| |
| err = security_kernel_post_load_data((char *)info->hdr, info->len, |
| LOADING_MODULE, "init_module"); |
| out: |
| if (err) |
| vfree(info->hdr); |
| |
| return err; |
| } |
| |
| static void free_copy(struct load_info *info, int flags) |
| { |
| if (flags & MODULE_INIT_COMPRESSED_FILE) |
| module_decompress_cleanup(info); |
| else |
| vfree(info->hdr); |
| } |
| |
| static int rewrite_section_headers(struct load_info *info, int flags) |
| { |
| unsigned int i; |
| |
| /* This should always be true, but let's be sure. */ |
| info->sechdrs[0].sh_addr = 0; |
| |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| Elf_Shdr *shdr = &info->sechdrs[i]; |
| |
| /* |
| * Mark all sections sh_addr with their address in the |
| * temporary image. |
| */ |
| shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; |
| |
| } |
| |
| /* Track but don't keep modinfo and version sections. */ |
| info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; |
| info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; |
| |
| return 0; |
| } |
| |
| /* |
| * Set up our basic convenience variables (pointers to section headers, |
| * search for module section index etc), and do some basic section |
| * verification. |
| * |
| * Set info->mod to the temporary copy of the module in info->hdr. The final one |
| * will be allocated in move_module(). |
| */ |
| static int setup_load_info(struct load_info *info, int flags) |
| { |
| unsigned int i; |
| |
| /* Try to find a name early so we can log errors with a module name */ |
| info->index.info = find_sec(info, ".modinfo"); |
| if (info->index.info) |
| info->name = get_modinfo(info, "name"); |
| |
| /* Find internal symbols and strings. */ |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| if (info->sechdrs[i].sh_type == SHT_SYMTAB) { |
| info->index.sym = i; |
| info->index.str = info->sechdrs[i].sh_link; |
| info->strtab = (char *)info->hdr |
| + info->sechdrs[info->index.str].sh_offset; |
| break; |
| } |
| } |
| |
| if (info->index.sym == 0) { |
| pr_warn("%s: module has no symbols (stripped?)\n", |
| info->name ?: "(missing .modinfo section or name field)"); |
| return -ENOEXEC; |
| } |
| |
| info->index.mod = find_sec(info, ".gnu.linkonce.this_module"); |
| if (!info->index.mod) { |
| pr_warn("%s: No module found in object\n", |
| info->name ?: "(missing .modinfo section or name field)"); |
| return -ENOEXEC; |
| } |
| /* This is temporary: point mod into copy of data. */ |
| info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset; |
| |
| /* |
| * If we didn't load the .modinfo 'name' field earlier, fall back to |
| * on-disk struct mod 'name' field. |
| */ |
| if (!info->name) |
| info->name = info->mod->name; |
| |
| if (flags & MODULE_INIT_IGNORE_MODVERSIONS) |
| info->index.vers = 0; /* Pretend no __versions section! */ |
| else |
| info->index.vers = find_sec(info, "__versions"); |
| |
| info->index.pcpu = find_pcpusec(info); |
| |
| return 0; |
| } |
| |
| static int check_modinfo(struct module *mod, struct load_info *info, int flags) |
| { |
| const char *modmagic = get_modinfo(info, "vermagic"); |
| int err; |
| |
| if (flags & MODULE_INIT_IGNORE_VERMAGIC) |
| modmagic = NULL; |
| |
| /* This is allowed: modprobe --force will invalidate it. */ |
| if (!modmagic) { |
| err = try_to_force_load(mod, "bad vermagic"); |
| if (err) |
| return err; |
| } else if (!same_magic(modmagic, vermagic, info->index.vers)) { |
| pr_err("%s: version magic '%s' should be '%s'\n", |
| info->name, modmagic, vermagic); |
| return -ENOEXEC; |
| } |
| |
| if (!get_modinfo(info, "intree")) { |
| if (!test_taint(TAINT_OOT_MODULE)) |
| pr_warn("%s: loading out-of-tree module taints kernel.\n", |
| mod->name); |
| add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); |
| } |
| |
| check_modinfo_retpoline(mod, info); |
| |
| if (get_modinfo(info, "staging")) { |
| add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); |
| pr_warn("%s: module is from the staging directory, the quality " |
| "is unknown, you have been warned.\n", mod->name); |
| } |
| |
| err = check_modinfo_livepatch(mod, info); |
| if (err) |
| return err; |
| |
| /* Set up license info based on the info section */ |
| set_license(mod, get_modinfo(info, "license")); |
| |
| if (get_modinfo(info, "test")) { |
| if (!test_taint(TAINT_TEST)) |
| pr_warn("%s: loading test module taints kernel.\n", |
| mod->name); |
| add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK); |
| } |
| |
| return 0; |
| } |
| |
| static int find_module_sections(struct module *mod, struct load_info *info) |
| { |
| mod->kp = section_objs(info, "__param", |
| sizeof(*mod->kp), &mod->num_kp); |
| mod->syms = section_objs(info, "__ksymtab", |
| sizeof(*mod->syms), &mod->num_syms); |
| mod->crcs = section_addr(info, "__kcrctab"); |
| mod->gpl_syms = section_objs(info, "__ksymtab_gpl", |
| sizeof(*mod->gpl_syms), |
| &mod->num_gpl_syms); |
| mod->gpl_crcs = section_addr(info, "__kcrctab_gpl"); |
| |
| #ifdef CONFIG_CONSTRUCTORS |
| mod->ctors = section_objs(info, ".ctors", |
| sizeof(*mod->ctors), &mod->num_ctors); |
| if (!mod->ctors) |
| mod->ctors = section_objs(info, ".init_array", |
| sizeof(*mod->ctors), &mod->num_ctors); |
| else if (find_sec(info, ".init_array")) { |
| /* |
| * This shouldn't happen with same compiler and binutils |
| * building all parts of the module. |
| */ |
| pr_warn("%s: has both .ctors and .init_array.\n", |
| mod->name); |
| return -EINVAL; |
| } |
| #endif |
| |
| mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1, |
| &mod->noinstr_text_size); |
| |
| #ifdef CONFIG_TRACEPOINTS |
| mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", |
| sizeof(*mod->tracepoints_ptrs), |
| &mod->num_tracepoints); |
| #endif |
| #ifdef CONFIG_TREE_SRCU |
| mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs", |
| sizeof(*mod->srcu_struct_ptrs), |
| &mod->num_srcu_structs); |
| #endif |
| #ifdef CONFIG_BPF_EVENTS |
| mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map", |
| sizeof(*mod->bpf_raw_events), |
| &mod->num_bpf_raw_events); |
| #endif |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size); |
| #endif |
| #ifdef CONFIG_JUMP_LABEL |
| mod->jump_entries = section_objs(info, "__jump_table", |
| sizeof(*mod->jump_entries), |
| &mod->num_jump_entries); |
| #endif |
| #ifdef CONFIG_EVENT_TRACING |
| mod->trace_events = section_objs(info, "_ftrace_events", |
| sizeof(*mod->trace_events), |
| &mod->num_trace_events); |
| mod->trace_evals = section_objs(info, "_ftrace_eval_map", |
| sizeof(*mod->trace_evals), |
| &mod->num_trace_evals); |
| #endif |
| #ifdef CONFIG_TRACING |
| mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", |
| sizeof(*mod->trace_bprintk_fmt_start), |
| &mod->num_trace_bprintk_fmt); |
| #endif |
| #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
| /* sechdrs[0].sh_size is always zero */ |
| mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION, |
| sizeof(*mod->ftrace_callsites), |
| &mod->num_ftrace_callsites); |
| #endif |
| #ifdef CONFIG_FUNCTION_ERROR_INJECTION |
| mod->ei_funcs = section_objs(info, "_error_injection_whitelist", |
| sizeof(*mod->ei_funcs), |
| &mod->num_ei_funcs); |
| #endif |
| #ifdef CONFIG_KPROBES |
| mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1, |
| &mod->kprobes_text_size); |
| mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist", |
| sizeof(unsigned long), |
| &mod->num_kprobe_blacklist); |
| #endif |
| #ifdef CONFIG_PRINTK_INDEX |
| mod->printk_index_start = section_objs(info, ".printk_index", |
| sizeof(*mod->printk_index_start), |
| &mod->printk_index_size); |
| #endif |
| #ifdef CONFIG_HAVE_STATIC_CALL_INLINE |
| mod->static_call_sites = section_objs(info, ".static_call_sites", |
| sizeof(*mod->static_call_sites), |
| &mod->num_static_call_sites); |
| #endif |
| #ifdef CONFIG_KUNIT |
| mod->kunit_suites = section_objs(info, ".kunit_test_suites", |
| sizeof(*mod->kunit_suites), |
| &mod->num_kunit_suites); |
| #endif |
| |
| mod->extable = section_objs(info, "__ex_table", |
| sizeof(*mod->extable), &mod->num_exentries); |
| |
| if (section_addr(info, "__obsparm")) |
| pr_warn("%s: Ignoring obsolete parameters\n", mod->name); |
| |
| info->debug = section_objs(info, "__dyndbg", |
| sizeof(*info->debug), &info->num_debug); |
| |
| return 0; |
| } |
| |
| static int move_module(struct module *mod, struct load_info *info) |
| { |
| int i; |
| void *ptr; |
| |
| /* Do the allocs. */ |
| ptr = module_alloc(mod->core_layout.size); |
| /* |
| * The pointer to this block is stored in the module structure |
| * which is inside the block. Just mark it as not being a |
| * leak. |
| */ |
| kmemleak_not_leak(ptr); |
| if (!ptr) |
| return -ENOMEM; |
| |
| memset(ptr, 0, mod->core_layout.size); |
| mod->core_layout.base = ptr; |
| |
| if (mod->init_layout.size) { |
| ptr = module_alloc(mod->init_layout.size); |
| /* |
| * The pointer to this block is stored in the module structure |
| * which is inside the block. This block doesn't need to be |
| * scanned as it contains data and code that will be freed |
| * after the module is initialized. |
| */ |
| kmemleak_ignore(ptr); |
| if (!ptr) { |
| module_memfree(mod->core_layout.base); |
| return -ENOMEM; |
| } |
| memset(ptr, 0, mod->init_layout.size); |
| mod->init_layout.base = ptr; |
| } else |
| mod->init_layout.base = NULL; |
| |
| #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC |
| /* Do the allocs. */ |
| ptr = vzalloc(mod->data_layout.size); |
| /* |
| * The pointer to this block is stored in the module structure |
| * which is inside the block. Just mark it as not being a |
| * leak. |
| */ |
| kmemleak_not_leak(ptr); |
| if (!ptr) { |
| module_memfree(mod->core_layout.base); |
| module_memfree(mod->init_layout.base); |
| return -ENOMEM; |
| } |
| |
| mod->data_layout.base = ptr; |
| #endif |
| /* Transfer each section which specifies SHF_ALLOC */ |
| pr_debug("final section addresses:\n"); |
| for (i = 0; i < info->hdr->e_shnum; i++) { |
| void *dest; |
| Elf_Shdr *shdr = &info->sechdrs[i]; |
| |
| if (!(shdr->sh_flags & SHF_ALLOC)) |
| continue; |
| |
| if (shdr->sh_entsize & INIT_OFFSET_MASK) |
| dest = mod->init_layout.base |
| + (shdr->sh_entsize & ~INIT_OFFSET_MASK); |
| else if (!(shdr->sh_flags & SHF_EXECINSTR)) |
| dest = mod->data_layout.base + shdr->sh_entsize; |
| else |
| dest = mod->core_layout.base + shdr->sh_entsize; |
| |
| if (shdr->sh_type != SHT_NOBITS) |
| memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); |
| /* Update sh_addr to point to copy in image. */ |
| shdr->sh_addr = (unsigned long)dest; |
| pr_debug("\t0x%lx %s\n", |
| (long)shdr->sh_addr, info->secstrings + shdr->sh_name); |
| } |
| |
| return 0; |
| } |
| |
| static int check_module_license_and_versions(struct module *mod) |
| { |
| int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE); |
| |
| /* |
| * ndiswrapper is under GPL by itself, but loads proprietary modules. |
| * Don't use add_taint_module(), as it would prevent ndiswrapper from |
| * using GPL-only symbols it needs. |
| */ |
| if (strcmp(mod->name, "ndiswrapper") == 0) |
| add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE); |
| |
| /* driverloader was caught wrongly pretending to be under GPL */ |
| if (strcmp(mod->name, "driverloader") == 0) |
| add_taint_module(mod, TAINT_PROPRIETARY_MODULE, |
| LOCKDEP_NOW_UNRELIABLE); |
| |
| /* lve claims to be GPL but upstream won't provide source */ |
| if (strcmp(mod->name, "lve") == 0) |
| add_taint_module(mod, TAINT_PROPRIETARY_MODULE, |
| LOCKDEP_NOW_UNRELIABLE); |
| |
| if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE)) |
| pr_warn("%s: module license taints kernel.\n", mod->name); |
| |
| #ifdef CONFIG_MODVERSIONS |
| if ((mod->num_syms && !mod->crcs) || |
| (mod->num_gpl_syms && !mod->gpl_crcs)) { |
| return try_to_force_load(mod, |
| "no versions for exported symbols"); |
| } |
| #endif |
| return 0; |
| } |
| |
| static void flush_module_icache(const struct module *mod) |
| { |
| /* |
| * Flush the instruction cache, since we've played with text. |
| * Do it before processing of module parameters, so the module |
| * can provide parameter accessor functions of its own. |
| */ |
| if (mod->init_layout.base) |
| flush_icache_range((unsigned long)mod->init_layout.base, |
| (unsigned long)mod->init_layout.base |
| + mod->init_layout.size); |
| flush_icache_range((unsigned long)mod->core_layout.base, |
| (unsigned long)mod->core_layout.base + mod->core_layout.size); |
| } |
| |
| int __weak module_frob_arch_sections(Elf_Ehdr *hdr, |
| Elf_Shdr *sechdrs, |
| char *secstrings, |
| struct module *mod) |
| { |
| return 0; |
| } |
| |
| /* module_blacklist is a comma-separated list of module names */ |
| static char *module_blacklist; |
| static bool blacklisted(const char *module_name) |
| { |
| const char *p; |
| size_t len; |
| |
| if (!module_blacklist) |
| return false; |
| |
| for (p = module_blacklist; *p; p += len) { |
| len = strcspn(p, ","); |
| if (strlen(module_name) == len && !memcmp(module_name, p, len)) |
| return true; |
| if (p[len] == ',') |
| len++; |
| } |
| return false; |
| } |
| core_param(module_blacklist, module_blacklist, charp, 0400); |
| |
| static struct module *layout_and_allocate(struct load_info *info, int flags) |
| { |
| struct module *mod; |
| unsigned int ndx; |
| int err; |
| |
| err = check_modinfo(info->mod, info, flags); |
| if (err) |
| return ERR_PTR(err); |
| |
| /* Allow arches to frob section contents and sizes. */ |
| err = module_frob_arch_sections(info->hdr, info->sechdrs, |
| info->secstrings, info->mod); |
| if (err < 0) |
| return ERR_PTR(err); |
| |
| err = module_enforce_rwx_sections(info->hdr, info->sechdrs, |
| info->secstrings, info->mod); |
| if (err < 0) |
| return ERR_PTR(err); |
| |
| /* We will do a special allocation for per-cpu sections later. */ |
| info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; |
| |
| /* |
| * Mark ro_after_init section with SHF_RO_AFTER_INIT so that |
| * layout_sections() can put it in the right place. |
| * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set. |
| */ |
| ndx = find_sec(info, ".data..ro_after_init"); |
| if (ndx) |
| info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; |
| /* |
| * Mark the __jump_table section as ro_after_init as well: these data |
| * structures are never modified, with the exception of entries that |
| * refer to code in the __init section, which are annotated as such |
| * at module load time. |
| */ |
| ndx = find_sec(info, "__jump_table"); |
| if (ndx) |
| info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; |
| |
| /* |
| * Determine total sizes, and put offsets in sh_entsize. For now |
| * this is done generically; there doesn't appear to be any |
| * special cases for the architectures. |
| */ |
| layout_sections(info->mod, info); |
| layout_symtab(info->mod, info); |
| |
| /* Allocate and move to the final place */ |
| err = move_module(info->mod, info); |
| if (err) |
| return ERR_PTR(err); |
| |
| /* Module has been copied to its final place now: return it. */ |
| mod = (void *)info->sechdrs[info->index.mod].sh_addr; |
| kmemleak_load_module(mod, info); |
| return mod; |
| } |
| |
| /* mod is no longer valid after this! */ |
| static void module_deallocate(struct module *mod, struct load_info *info) |
| { |
| percpu_modfree(mod); |
| module_arch_freeing_init(mod); |
| module_memfree(mod->init_layout.base); |
| module_memfree(mod->core_layout.base); |
| #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC |
| vfree(mod->data_layout.base); |
| #endif |
| } |
| |
| int __weak module_finalize(const Elf_Ehdr *hdr, |
| const Elf_Shdr *sechdrs, |
| struct module *me) |
| { |
| return 0; |
| } |
| |
| static int post_relocation(struct module *mod, const struct load_info *info) |
| { |
| /* Sort exception table now relocations are done. */ |
| sort_extable(mod->extable, mod->extable + mod->num_exentries); |
| |
| /* Copy relocated percpu area over. */ |
| percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr, |
| info->sechdrs[info->index.pcpu].sh_size); |
| |
| /* Setup kallsyms-specific fields. */ |
| add_kallsyms(mod, info); |
| |
| /* Arch-specific module finalizing. */ |
| return module_finalize(info->hdr, info->sechdrs, mod); |
| } |
| |
| /* Is this module of this name done loading? No locks held. */ |
| static bool finished_loading(const char *name) |
| { |
| struct module *mod; |
| bool ret; |
| |
| /* |
| * The module_mutex should not be a heavily contended lock; |
| * if we get the occasional sleep here, we'll go an extra iteration |
| * in the wait_event_interruptible(), which is harmless. |
| */ |
| sched_annotate_sleep(); |
| mutex_lock(&module_mutex); |
| mod = find_module_all(name, strlen(name), true); |
| ret = !mod || mod->state == MODULE_STATE_LIVE; |
| mutex_unlock(&module_mutex); |
| |
| return ret; |
| } |
| |
| /* Call module constructors. */ |
| static void do_mod_ctors(struct module *mod) |
| { |
| #ifdef CONFIG_CONSTRUCTORS |
| unsigned long i; |
| |
| for (i = 0; i < mod->num_ctors; i++) |
| mod->ctors[i](); |
| #endif |
| } |
| |
| /* For freeing module_init on success, in case kallsyms traversing */ |
| struct mod_initfree { |
| struct llist_node node; |
| void *module_init; |
| }; |
| |
| static void do_free_init(struct work_struct *w) |
| { |
| struct llist_node *pos, *n, *list; |
| struct mod_initfree *initfree; |
| |
| list = llist_del_all(&init_free_list); |
| |
| synchronize_rcu(); |
| |
| llist_for_each_safe(pos, n, list) { |
| initfree = container_of(pos, struct mod_initfree, node); |
| module_memfree(initfree->module_init); |
| kfree(initfree); |
| } |
| } |
| |
| #undef MODULE_PARAM_PREFIX |
| #define MODULE_PARAM_PREFIX "module." |
| /* Default value for module->async_probe_requested */ |
| static bool async_probe; |
| module_param(async_probe, bool, 0644); |
| |
| /* |
| * This is where the real work happens. |
| * |
| * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb |
| * helper command 'lx-symbols'. |
| */ |
| static noinline int do_init_module(struct module *mod) |
| { |
| int ret = 0; |
| struct mod_initfree *freeinit; |
| |
| freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL); |
| if (!freeinit) { |
| ret = -ENOMEM; |
| goto fail; |
| } |
| freeinit->module_init = mod->init_layout.base; |
| |
| do_mod_ctors(mod); |
| /* Start the module */ |
| if (mod->init != NULL) |
| ret = do_one_initcall(mod->init); |
| if (ret < 0) { |
| goto fail_free_freeinit; |
| } |
| if (ret > 0) { |
| pr_warn("%s: '%s'->init suspiciously returned %d, it should " |
| "follow 0/-E convention\n" |
| "%s: loading module anyway...\n", |
| __func__, mod->name, ret, __func__); |
| dump_stack(); |
| } |
| |
| /* Now it's a first class citizen! */ |
| mod->state = MODULE_STATE_LIVE; |
| blocking_notifier_call_chain(&module_notify_list, |
| MODULE_STATE_LIVE, mod); |
| |
| /* Delay uevent until module has finished its init routine */ |
| kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); |
| |
| /* |
| * We need to finish all async code before the module init sequence |
| * is done. This has potential to deadlock if synchronous module |
| * loading is requested from async (which is not allowed!). |
| * |
| * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous |
| * request_module() from async workers") for more details. |
| */ |
| if (!mod->async_probe_requested) |
| async_synchronize_full(); |
| |
| ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base + |
| mod->init_layout.size); |
| mutex_lock(&module_mutex); |
| /* Drop initial reference. */ |
| module_put(mod); |
| trim_init_extable(mod); |
| #ifdef CONFIG_KALLSYMS |
| /* Switch to core kallsyms now init is done: kallsyms may be walking! */ |
| rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms); |
| #endif |
| module_enable_ro(mod, true); |
| mod_tree_remove_init(mod); |
| module_arch_freeing_init(mod); |
| mod->init_layout.base = NULL; |
| mod->init_layout.size = 0; |
| mod->init_layout.ro_size = 0; |
| mod->init_layout.ro_after_init_size = 0; |
| mod->init_layout.text_size = 0; |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */ |
| mod->btf_data = NULL; |
| #endif |
| /* |
| * We want to free module_init, but be aware that kallsyms may be |
| * walking this with preempt disabled. In all the failure paths, we |
| * call synchronize_rcu(), but we don't want to slow down the success |
| * path. module_memfree() cannot be called in an interrupt, so do the |
| * work and call synchronize_rcu() in a work queue. |
| * |
| * Note that module_alloc() on most architectures creates W+X page |
| * mappings which won't be cleaned up until do_free_init() runs. Any |
| * code such as mark_rodata_ro() which depends on those mappings to |
| * be cleaned up needs to sync with the queued work - ie |
| * rcu_barrier() |
| */ |
| if (llist_add(&freeinit->node, &init_free_list)) |
| schedule_work(&init_free_wq); |
| |
| mutex_unlock(&module_mutex); |
| wake_up_all(&module_wq); |
| |
| return 0; |
| |
| fail_free_freeinit: |
| kfree(freeinit); |
| fail: |
| /* Try to protect us from buggy refcounters. */ |
| mod->state = MODULE_STATE_GOING; |
| synchronize_rcu(); |
| module_put(mod); |
| blocking_notifier_call_chain(&module_notify_list, |
| MODULE_STATE_GOING, mod); |
| klp_module_going(mod); |
| ftrace_release_mod(mod); |
| free_module(mod); |
| wake_up_all(&module_wq); |
| return ret; |
| } |
| |
| static int may_init_module(void) |
| { |
| if (!capable(CAP_SYS_MODULE) || modules_disabled) |
| return -EPERM; |
| |
| return 0; |
| } |
| |
| /* |
| * We try to place it in the list now to make sure it's unique before |
| * we dedicate too many resources. In particular, temporary percpu |
| * memory exhaustion. |
| */ |
| static int add_unformed_module(struct module *mod) |
| { |
| int err; |
| struct module *old; |
| |
| mod->state = MODULE_STATE_UNFORMED; |
| |
| again: |
| mutex_lock(&module_mutex); |
| old = find_module_all(mod->name, strlen(mod->name), true); |
| if (old != NULL) { |
| if (old->state != MODULE_STATE_LIVE) { |
| /* Wait in case it fails to load. */ |
| mutex_unlock(&module_mutex); |
| err = wait_event_interruptible(module_wq, |
| finished_loading(mod->name)); |
| if (err) |
| goto out_unlocked; |
| goto again; |
| } |
| err = -EEXIST; |
| goto out; |
| } |
| mod_update_bounds(mod); |
| list_add_rcu(&mod->list, &modules); |
| mod_tree_insert(mod); |
| err = 0; |
| |
| out: |
| mutex_unlock(&module_mutex); |
| out_unlocked: |
| return err; |
| } |
| |
| static int complete_formation(struct module *mod, struct load_info *info) |
| { |
| int err; |
| |
| mutex_lock(&module_mutex); |
| |
| /* Find duplicate symbols (must be called under lock). */ |
| err = verify_exported_symbols(mod); |
| if (err < 0) |
| goto out; |
| |
| /* This relies on module_mutex for list integrity. */ |
| module_bug_finalize(info->hdr, info->sechdrs, mod); |
| |
| if (module_check_misalignment(mod)) |
| goto out_misaligned; |
| |
| module_enable_ro(mod, false); |
| module_enable_nx(mod); |
| module_enable_x(mod); |
| |
| /* |
| * Mark state as coming so strong_try_module_get() ignores us, |
| * but kallsyms etc. can see us. |
| */ |
| mod->state = MODULE_STATE_COMING; |
| mutex_unlock(&module_mutex); |
| |
| return 0; |
| |
| out_misaligned: |
| err = -EINVAL; |
| out: |
| mutex_unlock(&module_mutex); |
| return err; |
| } |
| |
| static int prepare_coming_module(struct module *mod) |
| { |
| int err; |
| |
| ftrace_module_enable(mod); |
| err = klp_module_coming(mod); |
| if (err) |
| return err; |
| |
| err = blocking_notifier_call_chain_robust(&module_notify_list, |
| MODULE_STATE_COMING, MODULE_STATE_GOING, mod); |
| err = notifier_to_errno(err); |
| if (err) |
| klp_module_going(mod); |
| |
| return err; |
| } |
| |
| static int unknown_module_param_cb(char *param, char *val, const char *modname, |
| void *arg) |
| { |
| struct module *mod = arg; |
| int ret; |
| |
| if (strcmp(param, "async_probe") == 0) { |
| if (strtobool(val, &mod->async_probe_requested)) |
| mod->async_probe_requested = true; |
| return 0; |
| } |
| |
| /* Check for magic 'dyndbg' arg */ |
| ret = ddebug_dyndbg_module_param_cb(param, val, modname); |
| if (ret != 0) |
| pr_warn("%s: unknown parameter '%s' ignored\n", modname, param); |
| return 0; |
| } |
| |
| static void cfi_init(struct module *mod); |
| |
| /* |
| * Allocate and load the module: note that size of section 0 is always |
| * zero, and we rely on this for optional sections. |
| */ |
| static int load_module(struct load_info *info, const char __user *uargs, |
| int flags) |
| { |
| struct module *mod; |
| long err = 0; |
| char *after_dashes; |
| |
| /* |
| * Do the signature check (if any) first. All that |
| * the signature check needs is info->len, it does |
| * not need any of the section info. That can be |
| * set up later. This will minimize the chances |
| * of a corrupt module causing problems before |
| * we even get to the signature check. |
| * |
| * The check will also adjust info->len by stripping |
| * off the sig length at the end of the module, making |
| * checks against info->len more correct. |
| */ |
| err = module_sig_check(info, flags); |
| if (err) |
| goto free_copy; |
| |
| /* |
| * Do basic sanity checks against the ELF header and |
| * sections. |
| */ |
| err = elf_validity_check(info); |
| if (err) |
| goto free_copy; |
| |
| /* |
| * Everything checks out, so set up the section info |
| * in the info structure. |
| */ |
| err = setup_load_info(info, flags); |
| if (err) |
| goto free_copy; |
| |
| /* |
| * Now that we know we have the correct module name, check |
| * if it's blacklisted. |
| */ |
| if (blacklisted(info->name)) { |
| err = -EPERM; |
| pr_err("Module %s is blacklisted\n", info->name); |
| goto free_copy; |
| } |
| |
| err = rewrite_section_headers(info, flags); |
| if (err) |
| goto free_copy; |
| |
| /* Check module struct version now, before we try to use module. */ |
| if (!check_modstruct_version(info, info->mod)) { |
| err = -ENOEXEC; |
| goto free_copy; |
| } |
| |
| /* Figure out module layout, and allocate all the memory. */ |
| mod = layout_and_allocate(info, flags); |
| if (IS_ERR(mod)) { |
| err = PTR_ERR(mod); |
| goto free_copy; |
| } |
| |
| audit_log_kern_module(mod->name); |
| |
| /* Reserve our place in the list. */ |
| err = add_unformed_module(mod); |
| if (err) |
| goto free_module; |
| |
| #ifdef CONFIG_MODULE_SIG |
| mod->sig_ok = info->sig_ok; |
| if (!mod->sig_ok) { |
| pr_notice_once("%s: module verification failed: signature " |
| "and/or required key missing - tainting " |
| "kernel\n", mod->name); |
| add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK); |
| } |
| #endif |
| |
| /* To avoid stressing percpu allocator, do this once we're unique. */ |
| err = percpu_modalloc(mod, info); |
| if (err) |
| goto unlink_mod; |
| |
| /* Now module is in final location, initialize linked lists, etc. */ |
| err = module_unload_init(mod); |
| if (err) |
| goto unlink_mod; |
| |
| init_param_lock(mod); |
| |
| /* |
| * Now we've got everything in the final locations, we can |
| * find optional sections. |
| */ |
| err = find_module_sections(mod, info); |
| if (err) |
| goto free_unload; |
| |
| err = check_module_license_and_versions(mod); |
| if (err) |
| goto free_unload; |
| |
| /* Set up MODINFO_ATTR fields */ |
| setup_modinfo(mod, info); |
| |
| /* Fix up syms, so that st_value is a pointer to location. */ |
| err = simplify_symbols(mod, info); |
| if (err < 0) |
| goto free_modinfo; |
| |
| err = apply_relocations(mod, info); |
| if (err < 0) |
| goto free_modinfo; |
| |
| err = post_relocation(mod, info); |
| if (err < 0) |
| goto free_modinfo; |
| |
| flush_module_icache(mod); |
| |
| /* Setup CFI for the module. */ |
| cfi_init(mod); |
| |
| /* Now copy in args */ |
| mod->args = strndup_user(uargs, ~0UL >> 1); |
| if (IS_ERR(mod->args)) { |
| err = PTR_ERR(mod->args); |
| goto free_arch_cleanup; |
| } |
| |
| init_build_id(mod, info); |
| dynamic_debug_setup(mod, info->debug, info->num_debug); |
| |
| /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ |
| ftrace_module_init(mod); |
| |
| /* Finally it's fully formed, ready to start executing. */ |
| err = complete_formation(mod, info); |
| if (err) |
| goto ddebug_cleanup; |
| |
| err = prepare_coming_module(mod); |
| if (err) |
| goto bug_cleanup; |
| |
| mod->async_probe_requested = async_probe; |
| |
| /* Module is ready to execute: parsing args may do that. */ |
| after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, |
| -32768, 32767, mod, |
| unknown_module_param_cb); |
| if (IS_ERR(after_dashes)) { |
| err = PTR_ERR(after_dashes); |
| goto coming_cleanup; |
| } else if (after_dashes) { |
| pr_warn("%s: parameters '%s' after `--' ignored\n", |
| mod->name, after_dashes); |
| } |
| |
| /* Link in to sysfs. */ |
| err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp); |
| if (err < 0) |
| goto coming_cleanup; |
| |
| if (is_livepatch_module(mod)) { |
| err = copy_module_elf(mod, info); |
| if (err < 0) |
| goto sysfs_cleanup; |
| } |
| |
| /* Get rid of temporary copy. */ |
| free_copy(info, flags); |
| |
| /* Done! */ |
| trace_module_load(mod); |
| |
| return do_init_module(mod); |
| |
| sysfs_cleanup: |
| mod_sysfs_teardown(mod); |
| coming_cleanup: |
| mod->state = MODULE_STATE_GOING; |
| destroy_params(mod->kp, mod->num_kp); |
| blocking_notifier_call_chain(&module_notify_list, |
| MODULE_STATE_GOING, mod); |
| klp_module_going(mod); |
| bug_cleanup: |
| mod->state = MODULE_STATE_GOING; |
| /* module_bug_cleanup needs module_mutex protection */ |
| mutex_lock(&module_mutex); |
| module_bug_cleanup(mod); |
| mutex_unlock(&module_mutex); |
| |
| ddebug_cleanup: |
| ftrace_release_mod(mod); |
| dynamic_debug_remove(mod, info->debug); |
| synchronize_rcu(); |
| kfree(mod->args); |
| free_arch_cleanup: |
| cfi_cleanup(mod); |
| module_arch_cleanup(mod); |
| free_modinfo: |
| free_modinfo(mod); |
| free_unload: |
| module_unload_free(mod); |
| unlink_mod: |
| mutex_lock(&module_mutex); |
| /* Unlink carefully: kallsyms could be walking list. */ |
| list_del_rcu(&mod->list); |
| mod_tree_remove(mod); |
| wake_up_all(&module_wq); |
| /* Wait for RCU-sched synchronizing before releasing mod->list. */ |
| synchronize_rcu(); |
| mutex_unlock(&module_mutex); |
| free_module: |
| /* Free lock-classes; relies on the preceding sync_rcu() */ |
| lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size); |
| |
| module_deallocate(mod, info); |
| free_copy: |
| free_copy(info, flags); |
| return err; |
| } |
| |
| SYSCALL_DEFINE3(init_module, void __user *, umod, |
| unsigned long, len, const char __user *, uargs) |
| { |
| int err; |
| struct load_info info = { }; |
| |
| err = may_init_module(); |
| if (err) |
| return err; |
| |
| pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n", |
| umod, len, uargs); |
| |
| err = copy_module_from_user(umod, len, &info); |
| if (err) |
| return err; |
| |
| return load_module(&info, uargs, 0); |
| } |
| |
| SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) |
| { |
| struct load_info info = { }; |
| void *buf = NULL; |
| int len; |
| int err; |
| |
| err = may_init_module(); |
| if (err) |
| return err; |
| |
| pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags); |
| |
| if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS |
| |MODULE_INIT_IGNORE_VERMAGIC |
| |MODULE_INIT_COMPRESSED_FILE)) |
| return -EINVAL; |
| |
| len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL, |
| READING_MODULE); |
| if (len < 0) |
| return len; |
| |
| if (flags & MODULE_INIT_COMPRESSED_FILE) { |
| err = module_decompress(&info, buf, len); |
| vfree(buf); /* compressed data is no longer needed */ |
| if (err) |
| return err; |
| } else { |
| info.hdr = buf; |
| info.len = len; |
| } |
| |
| return load_module(&info, uargs, flags); |
| } |
| |
| static inline int within(unsigned long addr, void *start, unsigned long size) |
| { |
| return ((void *)addr >= start && (void *)addr < start + size); |
| } |
| |
| static void cfi_init(struct module *mod) |
| { |
| #ifdef CONFIG_CFI_CLANG |
| initcall_t *init; |
| #ifdef CONFIG_MODULE_UNLOAD |
| exitcall_t *exit; |
| #endif |
| |
| rcu_read_lock_sched(); |
| mod->cfi_check = (cfi_check_fn) |
| find_kallsyms_symbol_value(mod, "__cfi_check"); |
| init = (initcall_t *) |
| find_kallsyms_symbol_value(mod, "__cfi_jt_init_module"); |
| /* Fix init/exit functions to point to the CFI jump table */ |
| if (init) |
| mod->init = *init; |
| #ifdef CONFIG_MODULE_UNLOAD |
| exit = (exitcall_t *) |
| find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module"); |
| if (exit) |
| mod->exit = *exit; |
| #endif |
| rcu_read_unlock_sched(); |
| |
| cfi_module_add(mod, mod_tree.addr_min); |
| #endif |
| } |
| |
| static void cfi_cleanup(struct module *mod) |
| { |
| #ifdef CONFIG_CFI_CLANG |
| cfi_module_remove(mod, mod_tree.addr_min); |
| #endif |
| } |
| |
| /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */ |
| char *module_flags(struct module *mod, char *buf, bool show_state) |
| { |
| int bx = 0; |
| |
| BUG_ON(mod->state == MODULE_STATE_UNFORMED); |
| if (!mod->taints && !show_state) |
| goto out; |
| if (mod->taints || |
| mod->state == MODULE_STATE_GOING || |
| mod->state == MODULE_STATE_COMING) { |
| buf[bx++] = '('; |
| bx += module_flags_taint(mod->taints, buf + bx); |
| /* Show a - for module-is-being-unloaded */ |
| if (mod->state == MODULE_STATE_GOING && show_state) |
| buf[bx++] = '-'; |
| /* Show a + for module-is-being-loaded */ |
| if (mod->state == MODULE_STATE_COMING && show_state) |
| buf[bx++] = '+'; |
| buf[bx++] = ')'; |
| } |
| out: |
| buf[bx] = '\0'; |
| |
| return buf; |
| } |
| |
| /* Given an address, look for it in the module exception tables. */ |
| const struct exception_table_entry *search_module_extables(unsigned long addr) |
| { |
| const struct exception_table_entry *e = NULL; |
| struct module *mod; |
| |
| preempt_disable(); |
| mod = __module_address(addr); |
| if (!mod) |
| goto out; |
| |
| if (!mod->num_exentries) |
| goto out; |
| |
| e = search_extable(mod->extable, |
| mod->num_exentries, |
| addr); |
| out: |
| preempt_enable(); |
| |
| /* |
| * Now, if we found one, we are running inside it now, hence |
| * we cannot unload the module, hence no refcnt needed. |
| */ |
| return e; |
| } |
| |
| /** |
| * is_module_address() - is this address inside a module? |
| * @addr: the address to check. |
| * |
| * See is_module_text_address() if you simply want to see if the address |
| * is code (not data). |
| */ |
| bool is_module_address(unsigned long addr) |
| { |
| bool ret; |
| |
| preempt_disable(); |
| ret = __module_address(addr) != NULL; |
| preempt_enable(); |
| |
| return ret; |
| } |
| |
| /** |
| * __module_address() - get the module which contains an address. |
| * @addr: the address. |
| * |
| * Must be called with preempt disabled or module mutex held so that |
| * module doesn't get freed during this. |
| */ |
| struct module *__module_address(unsigned long addr) |
| { |
| struct module *mod; |
| struct mod_tree_root *tree; |
| |
| if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max) |
| tree = &mod_tree; |
| #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC |
| else if (addr >= mod_data_tree.addr_min && addr <= mod_data_tree.addr_max) |
| tree = &mod_data_tree; |
| #endif |
| else |
| return NULL; |
| |
| module_assert_mutex_or_preempt(); |
| |
| mod = mod_find(addr, tree); |
| if (mod) { |
| BUG_ON(!within_module(addr, mod)); |
| if (mod->state == MODULE_STATE_UNFORMED) |
| mod = NULL; |
| } |
| return mod; |
| } |
| |
| /** |
| * is_module_text_address() - is this address inside module code? |
| * @addr: the address to check. |
| * |
| |