diff options
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 4513 |
1 files changed, 0 insertions, 4513 deletions
diff --git a/kernel/module.c b/kernel/module.c deleted file mode 100644 index 33569a01d6e1..000000000000 --- a/kernel/module.c +++ /dev/null @@ -1,4513 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - Copyright (C) 2002 Richard Henderson - Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. - -*/ -#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/file.h> -#include <linux/fs.h> -#include <linux/sysfs.h> -#include <linux/kernel.h> -#include <linux/slab.h> -#include <linux/vmalloc.h> -#include <linux/elf.h> -#include <linux/proc_fs.h> -#include <linux/security.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 "module-internal.h" - -#define CREATE_TRACE_POINTS -#include <trace/events/module.h> - -#ifndef ARCH_SHF_SMALL -#define ARCH_SHF_SMALL 0 -#endif - -/* - * Modules' sections will be aligned on page boundaries - * to ensure complete separation of code and data, but - * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y - */ -#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX -# define debug_align(X) ALIGN(X, PAGE_SIZE) -#else -# define debug_align(X) (X) -#endif - -/* If this is set, the section belongs in the init part of the module */ -#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) - -/* - * Mutex protects: - * 1) List of modules (also safely readable with preempt_disable), - * 2) module_use links, - * 3) module_addr_min/module_addr_max. - * (delete and add uses RCU list operations). */ -DEFINE_MUTEX(module_mutex); -EXPORT_SYMBOL_GPL(module_mutex); -static LIST_HEAD(modules); - -/* Work queue for freeing init sections in success case */ -static struct work_struct init_free_wq; -static struct llist_head init_free_list; - -#ifdef CONFIG_MODULES_TREE_LOOKUP - -/* - * Use a latched RB-tree for __module_address(); this allows us to use - * RCU-sched lookups of the address from any context. - * - * This is conditional on PERF_EVENTS || TRACING because those can really hit - * __module_address() hard by doing a lot of stack unwinding; potentially from - * NMI context. - */ - -static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) -{ - struct module_layout *layout = container_of(n, struct module_layout, mtn.node); - - return (unsigned long)layout->base; -} - -static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) -{ - struct module_layout *layout = container_of(n, struct module_layout, mtn.node); - - return (unsigned long)layout->size; -} - -static __always_inline bool -mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b) -{ - return __mod_tree_val(a) < __mod_tree_val(b); -} - -static __always_inline int -mod_tree_comp(void *key, struct latch_tree_node *n) -{ - unsigned long val = (unsigned long)key; - unsigned long start, end; - - start = __mod_tree_val(n); - if (val < start) - return -1; - - end = start + __mod_tree_size(n); - if (val >= end) - return 1; - - return 0; -} - -static const struct latch_tree_ops mod_tree_ops = { - .less = mod_tree_less, - .comp = mod_tree_comp, -}; - -static struct mod_tree_root { - struct latch_tree_root root; - unsigned long addr_min; - unsigned long addr_max; -} mod_tree __cacheline_aligned = { - .addr_min = -1UL, -}; - -#define module_addr_min mod_tree.addr_min -#define module_addr_max mod_tree.addr_max - -static noinline void __mod_tree_insert(struct mod_tree_node *node) -{ - latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops); -} - -static void __mod_tree_remove(struct mod_tree_node *node) -{ - latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops); -} - -/* - * These modifications: insert, remove_init and remove; are serialized by the - * module_mutex. - */ -static void mod_tree_insert(struct module *mod) -{ - mod->core_layout.mtn.mod = mod; - mod->init_layout.mtn.mod = mod; - - __mod_tree_insert(&mod->core_layout.mtn); - if (mod->init_layout.size) - __mod_tree_insert(&mod->init_layout.mtn); -} - -static void mod_tree_remove_init(struct module *mod) -{ - if (mod->init_layout.size) - __mod_tree_remove(&mod->init_layout.mtn); -} - -static void mod_tree_remove(struct module *mod) -{ - __mod_tree_remove(&mod->core_layout.mtn); - mod_tree_remove_init(mod); -} - -static struct module *mod_find(unsigned long addr) -{ - struct latch_tree_node *ltn; - - ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops); - if (!ltn) - return NULL; - - return container_of(ltn, struct mod_tree_node, node)->mod; -} - -#else /* MODULES_TREE_LOOKUP */ - -static unsigned long module_addr_min = -1UL, module_addr_max = 0; - -static void mod_tree_insert(struct module *mod) { } -static void mod_tree_remove_init(struct module *mod) { } -static void mod_tree_remove(struct module *mod) { } - -static struct module *mod_find(unsigned long addr) -{ - struct module *mod; - - list_for_each_entry_rcu(mod, &modules, list, - lockdep_is_held(&module_mutex)) { - if (within_module(addr, mod)) - return mod; - } - - return NULL; -} - -#endif /* MODULES_TREE_LOOKUP */ - -/* - * Bounds of module text, for speeding up __module_address. - * Protected by module_mutex. - */ -static void __mod_update_bounds(void *base, unsigned int size) -{ - unsigned long min = (unsigned long)base; - unsigned long max = min + size; - - if (min < module_addr_min) - module_addr_min = min; - if (max > module_addr_max) - module_addr_max = max; -} - -static void mod_update_bounds(struct module *mod) -{ - __mod_update_bounds(mod->core_layout.base, mod->core_layout.size); - if (mod->init_layout.size) - __mod_update_bounds(mod->init_layout.base, mod->init_layout.size); -} - -#ifdef CONFIG_KGDB_KDB -struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ -#endif /* CONFIG_KGDB_KDB */ - -static void module_assert_mutex(void) -{ - lockdep_assert_held(&module_mutex); -} - -static void module_assert_mutex_or_preempt(void) -{ -#ifdef CONFIG_LOCKDEP - if (unlikely(!debug_locks)) - return; - - WARN_ON_ONCE(!rcu_read_lock_sched_held() && - !lockdep_is_held(&module_mutex)); -#endif -} - -static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); -module_param(sig_enforce, bool_enable_only, 0644); - -/* - * Export sig_enforce kernel cmdline parameter to allow other subsystems rely - * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. - */ -bool is_module_sig_enforced(void) -{ - return sig_enforce; -} -EXPORT_SYMBOL(is_module_sig_enforced); - -void set_module_sig_enforced(void) -{ - sig_enforce = true; -} - -/* Block module loading/unloading? */ -int modules_disabled = 0; -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. nfsd and lockd use this. - */ -void __noreturn __module_put_and_exit(struct module *mod, long code) -{ - module_put(mod); - do_exit(code); -} -EXPORT_SYMBOL(__module_put_and_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; -} - -/* 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 struct kernel_symbol __start___ksymtab_gpl_future[]; -extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; -extern const s32 __start___kcrctab[]; -extern const s32 __start___kcrctab_gpl[]; -extern const s32 __start___kcrctab_gpl_future[]; -#ifdef CONFIG_UNUSED_SYMBOLS -extern const struct kernel_symbol __start___ksymtab_unused[]; -extern const struct kernel_symbol __stop___ksymtab_unused[]; -extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; -extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; -extern const s32 __start___kcrctab_unused[]; -extern const s32 __start___kcrctab_unused_gpl[]; -#endif - -#ifndef CONFIG_MODVERSIONS -#define symversion(base, idx) NULL -#else -#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) -#endif - -static bool each_symbol_in_section(const struct symsearch *arr, - unsigned int arrsize, - struct module *owner, - bool (*fn)(const struct symsearch *syms, - struct module *owner, - void *data), - void *data) -{ - unsigned int j; - - for (j = 0; j < arrsize; j++) { - if (fn(&arr[j], owner, data)) - return true; - } - - return false; -} - -/* Returns true as soon as fn returns true, otherwise false. */ -bool each_symbol_section(bool (*fn)(const struct symsearch *arr, - struct module *owner, - void *data), - void *data) -{ - struct module *mod; - static const struct symsearch arr[] = { - { __start___ksymtab, __stop___ksymtab, __start___kcrctab, - NOT_GPL_ONLY, false }, - { __start___ksymtab_gpl, __stop___ksymtab_gpl, - __start___kcrctab_gpl, - GPL_ONLY, false }, - { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, - __start___kcrctab_gpl_future, - WILL_BE_GPL_ONLY, false }, -#ifdef CONFIG_UNUSED_SYMBOLS - { __start___ksymtab_unused, __stop___ksymtab_unused, - __start___kcrctab_unused, - NOT_GPL_ONLY, true }, - { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, - __start___kcrctab_unused_gpl, - GPL_ONLY, true }, -#endif - }; - - module_assert_mutex_or_preempt(); - - if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) - 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, false }, - { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, - mod->gpl_crcs, - GPL_ONLY, false }, - { mod->gpl_future_syms, - mod->gpl_future_syms + mod->num_gpl_future_syms, - mod->gpl_future_crcs, - WILL_BE_GPL_ONLY, false }, -#ifdef CONFIG_UNUSED_SYMBOLS - { mod->unused_syms, - mod->unused_syms + mod->num_unused_syms, - mod->unused_crcs, - NOT_GPL_ONLY, true }, - { mod->unused_gpl_syms, - mod->unused_gpl_syms + mod->num_unused_gpl_syms, - mod->unused_gpl_crcs, - GPL_ONLY, true }, -#endif - }; - - if (mod->state == MODULE_STATE_UNFORMED) - continue; - - if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) - return true; - } - return false; -} -EXPORT_SYMBOL_GPL(each_symbol_section); - -struct find_symbol_arg { - /* Input */ - const char *name; - bool gplok; - bool warn; - - /* Output */ - struct module *owner; - const s32 *crc; - const struct kernel_symbol *sym; -}; - -static bool check_exported_symbol(const struct symsearch *syms, - struct module *owner, - unsigned int symnum, void *data) -{ - struct find_symbol_arg *fsa = data; - - if (!fsa->gplok) { - if (syms->licence == GPL_ONLY) - return false; - if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { - pr_warn("Symbol %s is being used by a non-GPL module, " - "which will not be allowed in the future\n", - fsa->name); - } - } - -#ifdef CONFIG_UNUSED_SYMBOLS - if (syms->unused && fsa->warn) { - pr_warn("Symbol %s is marked as UNUSED, however this module is " - "using it.\n", fsa->name); - pr_warn("This symbol will go away in the future.\n"); - pr_warn("Please evaluate if this is the right api to use and " - "if it really is, submit a report to the linux kernel " - "mailing list together with submitting your code for " - "inclusion.\n"); - } -#endif - - fsa->owner = owner; - fsa->crc = symversion(syms->crcs, symnum); - fsa->sym = &syms->start[symnum]; - return true; -} - -static 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 -} - -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 -} - -static 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, - void *data) -{ - struct find_symbol_arg *fsa = data; - struct kernel_symbol *sym; - - sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, - sizeof(struct kernel_symbol), cmp_name); - - if (sym != NULL && check_exported_symbol(syms, owner, - sym - syms->start, data)) - return true; - - return false; -} - -/* Find an exported symbol and return it, along with, (optional) crc and - * (optional) module which owns it. Needs preempt disabled or module_mutex. */ -const struct kernel_symbol *find_symbol(const char *name, - struct module **owner, - const s32 **crc, - bool gplok, - bool warn) -{ - struct find_symbol_arg fsa; - - fsa.name = name; - fsa.gplok = gplok; - fsa.warn = warn; - - if (each_symbol_section(find_exported_symbol_in_section, &fsa)) { - if (owner) - *owner = fsa.owner; - if (crc) - *crc = fsa.crc; - return fsa.sym; - } - - pr_debug("Failed to find symbol %s\n", name); - return NULL; -} -EXPORT_SYMBOL_GPL(find_symbol); - -/* - * Search for module by name: must hold module_mutex (or preempt disabled - * for read-only access). - */ -static 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) -{ - module_assert_mutex(); - return find_module_all(name, strlen(name), false); -} -EXPORT_SYMBOL_GPL(find_module); - -#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. - * - * RETURNS: - * %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 char last_unloaded_module[MODULE_NAME_LEN+1]; - -#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() */ -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; -} -EXPORT_SYMBOL_GPL(ref_module); - -/* 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 - * - * Returns: - * -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]; - 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; - } - } - - /* Stop the machine so refcounts can't move and disable module. */ - 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 of the last unloaded module for diagnostic purposes */ - strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); - - 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; -} - -static inline void print_unload_info(struct seq_file *m, struct module *mod) -{ - struct module_use *use; - int printed_something = 0; - - seq_printf(m, " %i ", module_refcount(mod)); - - /* - * Always include a trailing , so userspace can differentiate - * between this and the old multi-field proc format. - */ - list_for_each_entry(use, &mod->source_list, source_list) { - printed_something = 1; - seq_printf(m, "%s,", use->source->name); - } - - if (mod->init != NULL && mod->exit == NULL) { - printed_something = 1; - seq_puts(m, "[permanent],"); - } - - if (!printed_something) - seq_puts(m, "-"); -} - -void __symbol_put(const char *symbol) -{ - struct module *owner; - - preempt_disable(); - if (!find_symbol(symbol, &owner, NULL, true, false)) - BUG(); - module_put(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 print_unload_info(struct seq_file *m, struct module *mod) -{ - /* We don't know the usage count, or what modules are using. */ - seq_puts(m, " - -"); -} - -static inline void module_unload_free(struct module *mod) -{ -} - -int ref_module(struct module *a, struct module *b) -{ - return strong_try_module_get(b); -} -EXPORT_SYMBOL_GPL(ref_module); - -static inline int module_unload_init(struct module *mod) -{ - return 0; -} -#endif /* CONFIG_MODULE_UNLOAD */ - -static size_t module_flags_taint(struct module *mod, char *buf) -{ - size_t l = 0; - int i; - - for (i = 0; i < TAINT_FLAGS_COUNT; i++) { - if (taint_flags[i].module && test_bit(i, &mod->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); - -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, buffer); - buffer[l++] = '\n'; - return l; -} - -static struct module_attribute modinfo_taint = - __ATTR(taint, 0444, show_taint, NULL); - -static struct module_attribute *modinfo_attrs[] = { - &module_uevent, - &modinfo_version, - &modinfo_srcversion, - &modinfo_initstate, - &modinfo_coresize, - &modinfo_initsize, - &modinfo_taint, -#ifdef CONFIG_MODULE_UNLOAD - &modinfo_refcnt, -#endif - NULL, -}; - -static const char vermagic[] = VERMAGIC_STRING; - -static 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 -} - -#ifdef CONFIG_MODVERSIONS - -static u32 resolve_rel_crc(const s32 *crc) -{ - return *(u32 *)((void *)crc + *crc); -} - -static int check_version(const struct load_info *info, - const char *symname, - struct module *mod, - const s32 *crc) -{ - Elf_Shdr *sechdrs = info->sechdrs; - unsigned int versindex = info->index.vers; - unsigned int i, num_versions; - struct modversion_info *versions; - - /* Exporting module didn't supply crcs? OK, we're already tainted. */ - if (!crc) - return 1; - - /* No versions at all? modprobe --force does this. */ - if (versindex == 0) - return try_to_force_load(mod, symname) == 0; - - versions = (void *) sechdrs[versindex].sh_addr; - num_versions = sechdrs[versindex].sh_size - / sizeof(struct modversion_info); - - for (i = 0; i < num_versions; i++) { - u32 crcval; - - if (strcmp(versions[i].name, symname) != 0) - continue; - - if (IS_ENABLED(CONFIG_MODULE_REL_CRCS)) - crcval = resolve_rel_crc(crc); - else - crcval = *crc; - if (versions[i].crc == crcval) - return 1; - pr_debug("Found checksum %X vs module %lX\n", - crcval, versions[i].crc); - goto bad_version; - } - - /* Broken toolchain. Warn once, then let it go.. */ - pr_warn_once("%s: no symbol version for %s\n", info->name, symname); - return 1; - -bad_version: - pr_warn("%s: disagrees about version of symbol %s\n", - info->name, symname); - return 0; -} - -static inline int check_modstruct_version(const struct load_info *info, - struct module *mod) -{ - const s32 *crc; - - /* - * Since this should be found in kernel (which can't be removed), no - * locking is necessary -- use preempt_disable() to placate lockdep. - */ - preempt_disable(); - if (!find_symbol("module_layout", NULL, &crc, true, false)) { - preempt_enable(); - BUG(); - } - preempt_enable(); - return check_version(info, "module_layout", mod, crc); -} - -/* First part is kernel version, which we ignore if module has crcs. */ -static inline int same_magic(const char *amagic, const char *bmagic, - bool has_crcs) -{ - if (has_crcs) { - amagic += strcspn(amagic, " "); - bmagic += strcspn(bmagic, " "); - } - return strcmp(amagic, bmagic) == 0; -} -#else -static inline int check_version(const struct load_info *info, - const char *symname, - struct module *mod, - const s32 *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 */ - -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; -} - - -/* 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 module *owner; - const struct kernel_symbol *sym; - const s32 *crc; - 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); - sym = find_symbol(name, &owner, &crc, - !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); - if (!sym) - goto unlock; - - if (!check_version(info, name, mod, crc)) { - sym = ERR_PTR(-EINVAL); - goto getname; - } - - err = verify_namespace_is_imported(info, sym, mod); - if (err) { - sym = ERR_PTR(err); - goto getname; - } - - err = ref_module(mod, owner); - if (err) { - sym = ERR_PTR(err); - goto getname; - } - -getname: - /* We must make copy under the lock if we failed to get ref. */ - strncpy(ownername, module_name(owner), MODULE_NAME_LEN); -unlock: - mutex_unlock(&module_mutex); - return 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; -} - -/* - * /sys/module/foo/sections stuff - * J. Corbet <corbet@lwn.net> - */ -#ifdef CONFIG_SYSFS - -#ifdef CONFIG_KALLSYMS -static inline bool sect_empty(const Elf_Shdr *sect) -{ - return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; -} - -struct module_sect_attr { - struct module_attribute mattr; - char *name; - unsigned long address; -}; - -struct module_sect_attrs { - struct attribute_group grp; - unsigned int nsections; - struct module_sect_attr attrs[0]; -}; - -static ssize_t module_sect_show(struct module_attribute *mattr, - struct module_kobject *mk, char *buf) -{ - struct module_sect_attr *sattr = - container_of(mattr, struct module_sect_attr, mattr); - return sprintf(buf, "0x%px\n", kptr_restrict < 2 ? - (void *)sattr->address : NULL); -} - -static void free_sect_attrs(struct module_sect_attrs *sect_attrs) -{ - unsigned int section; - - for (section = 0; section < sect_attrs->nsections; section++) - kfree(sect_attrs->attrs[section].name); - kfree(sect_attrs); -} - -static void add_sect_attrs(struct module *mod, const struct load_info *info) -{ - unsigned int nloaded = 0, i, size[2]; - struct module_sect_attrs *sect_attrs; - struct module_sect_attr *sattr; - struct attribute **gattr; - - /* Count loaded sections and allocate structures */ - for (i = 0; i < info->hdr->e_shnum; i++) - if (!sect_empty(&info->sechdrs[i])) - nloaded++; - size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), - sizeof(sect_attrs->grp.attrs[0])); - size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]); - sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); - if (sect_attrs == NULL) - return; - - /* Setup section attributes. */ - sect_attrs->grp.name = "sections"; - sect_attrs->grp.attrs = (void *)sect_attrs + size[0]; - - sect_attrs->nsections = 0; - sattr = §_attrs->attrs[0]; - gattr = §_attrs->grp.attrs[0]; - for (i = 0; i < info->hdr->e_shnum; i++) { - Elf_Shdr *sec = &info->sechdrs[i]; - if (sect_empty(sec)) - continue; - sattr->address = sec->sh_addr; - sattr->name = kstrdup(info->secstrings + sec->sh_name, - GFP_KERNEL); - if (sattr->name == NULL) - goto out; - sect_attrs->nsections++; - sysfs_attr_init(&sattr->mattr.attr); - sattr->mattr.show = module_sect_show; - sattr->mattr.store = NULL; - sattr->mattr.attr.name = sattr->name; - sattr->mattr.attr.mode = S_IRUSR; - *(gattr++) = &(sattr++)->mattr.attr; - } - *gattr = NULL; - - if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) - goto out; - - mod->sect_attrs = sect_attrs; - return; - out: - free_sect_attrs(sect_attrs); -} - -static void remove_sect_attrs(struct module *mod) -{ - if (mod->sect_attrs) { - sysfs_remove_group(&mod->mkobj.kobj, - &mod->sect_attrs->grp); - /* We are positive that no one is using any sect attrs - * at this point. Deallocate immediately. */ - free_sect_attrs(mod->sect_attrs); - mod->sect_attrs = NULL; - } -} - -/* - * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. - */ - -struct module_notes_attrs { - struct kobject *dir; - unsigned int notes; - struct bin_attribute attrs[0]; -}; - -static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buf, loff_t pos, size_t count) -{ - /* - * The caller checked the pos and count against our size. - */ - memcpy(buf, bin_attr->private + pos, count); - return count; -} - -static void free_notes_attrs(struct module_notes_attrs *notes_attrs, - unsigned int i) -{ - if (notes_attrs->dir) { - while (i-- > 0) - sysfs_remove_bin_file(notes_attrs->dir, - ¬es_attrs->attrs[i]); - kobject_put(notes_attrs->dir); - } - kfree(notes_attrs); -} - -static void add_notes_attrs(struct module *mod, const struct load_info *info) -{ - unsigned int notes, loaded, i; - struct module_notes_attrs *notes_attrs; - struct bin_attribute *nattr; - - /* failed to create section attributes, so can't create notes */ - if (!mod->sect_attrs) - return; - - /* Count notes sections and allocate structures. */ - notes = 0; - for (i = 0; i < info->hdr->e_shnum; i++) - if (!sect_empty(&info->sechdrs[i]) && - (info->sechdrs[i].sh_type == SHT_NOTE)) - ++notes; - - if (notes == 0) - return; - - notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), - GFP_KERNEL); - if (notes_attrs == NULL) - return; - - notes_attrs->notes = notes; - nattr = ¬es_attrs->attrs[0]; - for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { - if (sect_empty(&info->sechdrs[i])) - continue; - if (info->sechdrs[i].sh_type == SHT_NOTE) { - sysfs_bin_attr_init(nattr); - nattr->attr.name = mod->sect_attrs->attrs[loaded].name; - nattr->attr.mode = S_IRUGO; - nattr->size = info->sechdrs[i].sh_size; - nattr->private = (void *) info->sechdrs[i].sh_addr; - nattr->read = module_notes_read; - ++nattr; - } - ++loaded; - } - - notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); - if (!notes_attrs->dir) - goto out; - - for (i = 0; i < notes; ++i) - if (sysfs_create_bin_file(notes_attrs->dir, - ¬es_attrs->attrs[i])) - goto out; - - mod->notes_attrs = notes_attrs; - return; - - out: - free_notes_attrs(notes_attrs, i); -} - -static void remove_notes_attrs(struct module *mod) -{ - if (mod->notes_attrs) - free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); -} - -#else - -static inline void add_sect_attrs(struct module *mod, - const struct load_info *info) -{ -} - -static inline void remove_sect_attrs(struct module *mod) -{ -} - -static inline void add_notes_attrs(struct module *mod, - const struct load_info *info) -{ -} - -static inline void remove_notes_attrs(struct module *mod) -{ -} -#endif /* CONFIG_KALLSYMS */ - -static void del_usage_links(struct module *mod) -{ -#ifdef CONFIG_MODULE_UNLOAD - struct module_use *use; - - mutex_lock(&module_mutex); - list_for_each_entry(use, &mod->target_list, target_list) - sysfs_remove_link(use->target->holders_dir, mod->name); - mutex_unlock(&module_mutex); -#endif -} - -static int add_usage_links(struct module *mod) -{ - int ret = 0; -#ifdef CONFIG_MODULE_UNLOAD - struct module_use *use; - - mutex_lock(&module_mutex); - list_for_each_entry(use, &mod->target_list, target_list) { - ret = sysfs_create_link(use->target->holders_dir, - &mod->mkobj.kobj, mod->name); - if (ret) - break; - } - mutex_unlock(&module_mutex); - if (ret) - del_usage_links(mod); -#endif - return ret; -} - -static void module_remove_modinfo_attrs(struct module *mod, int end); - -static int module_add_modinfo_attrs(struct module *mod) -{ - struct module_attribute *attr; - struct module_attribute *temp_attr; - int error = 0; - int i; - - mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * - (ARRAY_SIZE(modinfo_attrs) + 1)), - GFP_KERNEL); - if (!mod->modinfo_attrs) - return -ENOMEM; - - temp_attr = mod->modinfo_attrs; - for (i = 0; (attr = modinfo_attrs[i]); i++) { - if (!attr->test || attr->test(mod)) { - memcpy(temp_attr, attr, sizeof(*temp_attr)); - sysfs_attr_init(&temp_attr->attr); - error = sysfs_create_file(&mod->mkobj.kobj, - &temp_attr->attr); - if (error) - goto error_out; - ++temp_attr; - } - } - - return 0; - -error_out: - if (i > 0) - module_remove_modinfo_attrs(mod, --i); - else - kfree(mod->modinfo_attrs); - return error; -} - -static void module_remove_modinfo_attrs(struct module *mod, int end) -{ - struct module_attribute *attr; - int i; - - for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { - if (end >= 0 && i > end) - break; - /* pick a field to test for end of list */ - if (!attr->attr.name) - break; - sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); - if (attr->free) - attr->free(mod); - } - kfree(mod->modinfo_attrs); -} - -static void mod_kobject_put(struct module *mod) -{ - DECLARE_COMPLETION_ONSTACK(c); - mod->mkobj.kobj_completion = &c; - kobject_put(&mod->mkobj.kobj); - wait_for_completion(&c); -} - -static int mod_sysfs_init(struct module *mod) -{ - int err; - struct kobject *kobj; - - if (!module_sysfs_initialized) { - pr_err("%s: module sysfs not initialized\n", mod->name); - err = -EINVAL; - goto out; - } - - kobj = kset_find_obj(module_kset, mod->name); - if (kobj) { - pr_err("%s: module is already loaded\n", mod->name); - kobject_put(kobj); - err = -EINVAL; - goto out; - } - - mod->mkobj.mod = mod; - - memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); - mod->mkobj.kobj.kset = module_kset; - err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, - "%s", mod->name); - if (err) - mod_kobject_put(mod); - - /* delay uevent until full sysfs population */ -out: - return err; -} - -static int mod_sysfs_setup(struct module *mod, - const struct load_info *info, - struct kernel_param *kparam, - unsigned int num_params) -{ - int err; - - err = mod_sysfs_init(mod); - if (err) - goto out; - - mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); - if (!mod->holders_dir) { - err = -ENOMEM; - goto out_unreg; - } - - err = module_param_sysfs_setup(mod, kparam, num_params); - if (err) - goto out_unreg_holders; - - err = module_add_modinfo_attrs(mod); - if (err) - goto out_unreg_param; - - err = add_usage_links(mod); - if (err) - goto out_unreg_modinfo_attrs; - - add_sect_attrs(mod, info); - add_notes_attrs(mod, info); - - kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); - return 0; - -out_unreg_modinfo_attrs: - module_remove_modinfo_attrs(mod, -1); -out_unreg_param: - module_param_sysfs_remove(mod); -out_unreg_holders: - kobject_put(mod->holders_dir); -out_unreg: - mod_kobject_put(mod); -out: - return err; -} - -static void mod_sysfs_fini(struct module *mod) -{ - remove_notes_attrs(mod); - remove_sect_attrs(mod); - mod_kobject_put(mod); -} - -static void init_param_lock(struct module *mod) -{ - mutex_init(&mod->param_lock); -} -#else /* !CONFIG_SYSFS */ - -static int mod_sysfs_setup(struct module *mod, - const struct load_info *info, - struct kernel_param *kparam, - unsigned int num_params) -{ - return 0; -} - -static void mod_sysfs_fini(struct module *mod) -{ -} - -static void module_remove_modinfo_attrs(struct module *mod, int end) -{ -} - -static void del_usage_links(struct module *mod) -{ -} - -static void init_param_lock(struct module *mod) -{ -} -#endif /* CONFIG_SYSFS */ - -static void mod_sysfs_teardown(struct module *mod) -{ - del_usage_links(mod); - module_remove_modinfo_attrs(mod, -1); - module_param_sysfs_remove(mod); - kobject_put(mod->mkobj.drivers_dir); - kobject_put(mod->holders_dir); - mod_sysfs_fini(mod); -} - -#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX -/* - * LKM RO/NX protection: protect module's text/ro-data - * from modification and any data from execution. - * - * General layout of module is: - * [text] [read-only-data] [ro-after-init] [writable data] - * text_size -----^ ^ ^ ^ - * ro_size ------------------------| | | - * ro_after_init_size -----------------------------| | - * size -----------------------------------------------------------| - * - * These values are always page-aligned (as is base) - */ -static void frob_text(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); - set_memory((unsigned long)layout->base, - layout->text_size >> PAGE_SHIFT); -} - -#ifdef CONFIG_STRICT_MODULE_RWX -static void frob_rodata(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); - set_memory((unsigned long)layout->base + layout->text_size, - (layout->ro_size - layout->text_size) >> PAGE_SHIFT); -} - -static void frob_ro_after_init(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); - set_memory((unsigned long)layout->base + layout->ro_size, - (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); -} - -static void frob_writable_data(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1)); - set_memory((unsigned long)layout->base + layout->ro_after_init_size, - (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); -} - -/* livepatching wants to disable read-only so it can frob module. */ -void module_disable_ro(const struct module *mod) -{ - if (!rodata_enabled) - return; - - frob_text(&mod->core_layout, set_memory_rw); - frob_rodata(&mod->core_layout, set_memory_rw); - frob_ro_after_init(&mod->core_layout, set_memory_rw); - frob_text(&mod->init_layout, set_memory_rw); - frob_rodata(&mod->init_layout, set_memory_rw); -} - -void module_enable_ro(const struct module *mod, bool after_init) -{ - if (!rodata_enabled) - return; - - set_vm_flush_reset_perms(mod->core_layout.base); - set_vm_flush_reset_perms(mod->init_layout.base); - frob_text(&mod->core_layout, set_memory_ro); - - frob_rodata(&mod->core_layout, set_memory_ro); - frob_text(&mod->init_layout, set_memory_ro); - frob_rodata(&mod->init_layout, set_memory_ro); - - if (after_init) - frob_ro_after_init(&mod->core_layout, set_memory_ro); -} - -static void module_enable_nx(const struct module *mod) -{ - frob_rodata(&mod->core_layout, set_memory_nx); - frob_ro_after_init(&mod->core_layout, set_memory_nx); - frob_writable_data(&mod->core_layout, set_memory_nx); - frob_rodata(&mod->init_layout, set_memory_nx); - frob_writable_data(&mod->init_layout, set_memory_nx); -} - -#else /* !CONFIG_STRICT_MODULE_RWX */ -static void module_enable_nx(const struct module *mod) { } -#endif /* CONFIG_STRICT_MODULE_RWX */ -static void module_enable_x(const struct module *mod) -{ - frob_text(&mod->core_layout, set_memory_x); - frob_text(&mod->init_layout, set_memory_x); -} -#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ -static void module_enable_nx(const struct module *mod) { } -static void module_enable_x(const struct module *mod) { } -#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ - - -#ifdef CONFIG_LIVEPATCH -/* - * Persist Elf information about a module. Copy the Elf header, - * section header table, section string table, and symtab section - * index from info to mod->klp_info. - */ -static int copy_module_elf(struct module *mod, struct load_info *info) -{ - unsigned int size, symndx; - int ret; - - size = sizeof(*mod->klp_info); - mod->klp_info = kmalloc(size, GFP_KERNEL); - if (mod->klp_info == NULL) - return -ENOMEM; - - /* Elf header */ - size = sizeof(mod->klp_info->hdr); - memcpy(&mod->klp_info->hdr, info->hdr, size); - - /* Elf section header table */ - size = sizeof(*info->sechdrs) * info->hdr->e_shnum; - mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL); - if (mod->klp_info->sechdrs == NULL) { - ret = -ENOMEM; - goto free_info; - } - - /* Elf section name string table */ - size = info->sechdrs[info->hdr->e_shstrndx].sh_size; - mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL); - if (mod->klp_info->secstrings == NULL) { - ret = -ENOMEM; - goto free_sechdrs; - } - - /* Elf symbol section index */ - symndx = info->index.sym; - mod->klp_info->symndx = symndx; - - /* - * For livepatch modules, core_kallsyms.symtab is a complete - * copy of the original symbol table. Adjust sh_addr to point - * to core_kallsyms.symtab since the copy of the symtab in module - * init memory is freed at the end of do_init_module(). - */ - mod->klp_info->sechdrs[symndx].sh_addr = \ - (unsigned long) mod->core_kallsyms.symtab; - - return 0; - -free_sechdrs: - kfree(mod->klp_info->sechdrs); -free_info: - kfree(mod->klp_info); - return ret; -} - -static void free_module_elf(struct module *mod) -{ - kfree(mod->klp_info->sechdrs); - kfree(mod->klp_info->secstrings); - kfree(mod->klp_info); -} -#else /* !CONFIG_LIVEPATCH */ -static int copy_module_elf(struct module *mod, struct load_info *info) -{ - return 0; -} - -static void free_module_elf(struct module *mod) -{ -} -#endif /* CONFIG_LIVEPATCH */ - -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) -{ -} - -/* 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(); - mutex_unlock(&module_mutex); - - /* 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->core_layout.base, mod->core_layout.size); - - /* Finally, free the core (containing the module structure) */ - module_memfree(mod->core_layout.base); -} - -void *__symbol_get(const char *symbol) -{ - struct module *owner; - const struct kernel_symbol *sym; - - preempt_disable(); - sym = find_symbol(symbol, &owner, NULL, true, true); - if (sym && strong_try_module_get(owner)) - sym = NULL; - preempt_enable(); - - return sym ? (void *)kernel_symbol_value(sym) : NULL; -} -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; - struct module *owner; - 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 }, - { mod->gpl_future_syms, mod->num_gpl_future_syms }, -#ifdef CONFIG_UNUSED_SYMBOLS - { mod->unused_syms, mod->num_unused_syms }, - { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, -#endif - }; - - for (i = 0; i < ARRAY_SIZE(arr); i++) { - for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { - if (find_symbol(kernel_symbol_name(s), &owner, NULL, - true, false)) { - pr_err("%s: exports duplicate symbol %s" - " (owned by %s)\n", - mod->name, kernel_symbol_name(s), - module_name(owner)); - return -ENOEXEC; - } - } - } - return 0; -} - -/* 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. */ - if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK) - 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; - - /* Livepatch relocation sections are applied by livepatch */ - if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) - continue; - - 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. */ -static long 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; -} - -/* 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; - - if ((s->sh_flags & masks[m][0]) != masks[m][0] - || (s->sh_flags & masks[m][1]) - || s->sh_entsize != ~0UL - || strstarts(sname, ".init")) - continue; - s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i); - pr_debug("\t%s\n", sname); - } - switch (m) { - case 0: /* executable */ - mod->core_layout.size = debug_align(mod->core_layout.size); - mod->core_layout.text_size = mod->core_layout.size; - break; - case 1: /* RO: text and ro-data */ - mod->core_layout.size = debug_align(mod->core_layout.size); - mod->core_layout.ro_size = mod->core_layout.size; - break; - case 2: /* RO after init */ - mod->core_layout.size = debug_align(mod->core_layout.size); - mod->core_layout.ro_after_init_size = mod->core_layout.size; - break; - case 4: /* whole core */ - mod->core_layout.size = debug_align(mod->core_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 - || !strstarts(sname, ".init")) - continue; - s->sh_entsize = (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 = debug_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 = debug_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 = debug_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); - } -} - -#ifdef CONFIG_KALLSYMS - -/* Lookup exported symbol in given range of kernel_symbols */ -static const struct kernel_symbol *lookup_exported_symbol(const char *name, - const struct kernel_symbol *start, - const struct kernel_symbol *stop) -{ - return bsearch(name, start, stop - start, - sizeof(struct kernel_symbol), cmp_name); -} - -static int is_exported(const char *name, unsigned long value, - const struct module *mod) -{ - const struct kernel_symbol *ks; - if (!mod) - ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab); - else - ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms); - - return ks != NULL && kernel_symbol_value(ks) == value; -} - -/* As per nm */ -static char elf_type(const Elf_Sym *sym, const struct load_info *info) -{ - const Elf_Shdr *sechdrs = info->sechdrs; - - if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { - if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) - return 'v'; - else - return 'w'; - } - if (sym->st_shndx == SHN_UNDEF) - return 'U'; - if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu) - return 'a'; - if (sym->st_shndx >= SHN_LORESERVE) - return '?'; - if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR) - return 't'; - if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC - && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) { - if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE)) - return 'r'; - else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) - return 'g'; - else - return 'd'; - } - if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { - if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) - return 's'; - else - return 'b'; - } - if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name, - ".debug")) { - return 'n'; - } - return '?'; -} - -static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, - unsigned int shnum, unsigned int pcpundx) -{ - const Elf_Shdr *sec; - - if (src->st_shndx == SHN_UNDEF - || src->st_shndx >= shnum - || !src->st_name) - return false; - -#ifdef CONFIG_KALLSYMS_ALL - if (src->st_shndx == pcpundx) - return true; -#endif - - sec = sechdrs + src->st_shndx; - if (!(sec->sh_flags & SHF_ALLOC) -#ifndef CONFIG_KALLSYMS_ALL - || !(sec->sh_flags & SHF_EXECINSTR) -#endif - || (sec->sh_entsize & INIT_OFFSET_MASK)) - return false; - - return true; -} - -/* - * We only allocate and copy the strings needed by the parts of symtab - * we keep. This is simple, but has the effect of making multiple - * copies of duplicates. We could be more sophisticated, see - * linux-kernel thread starting with - * <73defb5e4bca04a6431392cc341112b1@localhost>. - */ -static void layout_symtab(struct module *mod, struct load_info *info) -{ - Elf_Shdr *symsect = info->sechdrs + info->index.sym; - Elf_Shdr *strsect = info->sechdrs + info->index.str; - const Elf_Sym *src; - unsigned int i, nsrc, ndst, strtab_size = 0; - - /* Put symbol section at end of init part of module. */ - symsect->sh_flags |= SHF_ALLOC; - symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect, - info->index.sym) | INIT_OFFSET_MASK; - pr_debug("\t%s\n", info->secstrings + symsect->sh_name); - - src = (void *)info->hdr + symsect->sh_offset; - nsrc = symsect->sh_size / sizeof(*src); - - /* Compute total space required for the core symbols' strtab. */ - for (ndst = i = 0; i < nsrc; i++) { - if (i == 0 || is_livepatch_module(mod) || - is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, - info->index.pcpu)) { - strtab_size += strlen(&info->strtab[src[i].st_name])+1; - ndst++; - } - } - - /* Append room for core symbols at end of core part. */ - info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1); - info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym); - mod->core_layout.size += strtab_size; - info->core_typeoffs = mod->core_layout.size; - mod->core_layout.size += ndst * sizeof(char); - mod->core_layout.size = debug_align(mod->core_layout.size); - - /* Put string table section at end of init part of module. */ - strsect->sh_flags |= SHF_ALLOC; - strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect, - info->index.str) | INIT_OFFSET_MASK; - pr_debug("\t%s\n", info->secstrings + strsect->sh_name); - - /* We'll tack temporary mod_kallsyms on the end. */ - mod->init_layout.size = ALIGN(mod->init_layout.size, - __alignof__(struct mod_kallsyms)); - info->mod_kallsyms_init_off = mod->init_layout.size; - mod->init_layout.size += sizeof(struct mod_kallsyms); - info->init_typeoffs = mod->init_layout.size; - mod->init_layout.size += nsrc * sizeof(char); - mod->init_layout.size = debug_align(mod->init_layout.size); -} - -/* - * We use the full symtab and strtab which layout_symtab arranged to - * be appended to the init section. Later we switch to the cut-down - * core-only ones. - */ -static void add_kallsyms(struct module *mod, const struct load_info *info) -{ - unsigned int i, ndst; - const Elf_Sym *src; - Elf_Sym *dst; - char *s; - Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; - - /* Set up to point into init section. */ - mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off; - - mod->kallsyms->symtab = (void *)symsec->sh_addr; - mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym); - /* Make sure we get permanent strtab: don't use info->strtab. */ - mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr; - mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs; - - /* - * Now populate the cut down core kallsyms for after init - * and set types up while we still have access to sections. - */ - mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs; - mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs; - mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs; - src = mod->kallsyms->symtab; - for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) { - mod->kallsyms->typetab[i] = elf_type(src + i, info); - if (i == 0 || is_livepatch_module(mod) || - is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, - info->index.pcpu)) { - mod->core_kallsyms.typetab[ndst] = - mod->kallsyms->typetab[i]; - dst[ndst] = src[i]; - dst[ndst++].st_name = s - mod->core_kallsyms.strtab; - s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name], - KSYM_NAME_LEN) + 1; - } - } - mod->core_kallsyms.num_symtab = ndst; -} -#else -static inline void layout_symtab(struct module *mod, struct load_info *info) -{ -} - -static void add_kallsyms(struct module *mod, const struct load_info *info) -{ -} -#endif /* CONFIG_KALLSYMS */ - -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_exec(size); -} - -bool __weak module_exit_section(const char *name) -{ - return strstarts(name, ".exit"); -} - -#ifdef CONFIG_DEBUG_KMEMLEAK -static void kmemleak_load_module(const struct module *mod, - const struct load_info *info) -{ - unsigned int i; - - /* only scan the sections containing data */ - kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); - - for (i = 1; i < info->hdr->e_shnum; i++) { - /* Scan all writable sections that's not executable */ - if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) || - !(info->sechdrs[i].sh_flags & SHF_WRITE) || - (info->sechdrs[i].sh_flags & SHF_EXECINSTR)) - continue; - - kmemleak_scan_area((void *)info->sechdrs[i].sh_addr, - info->sechdrs[i].sh_size, GFP_KERNEL); - } -} -#else -static inline void kmemleak_load_module(const struct module *mod, - const struct load_info *info) -{ -} -#endif - -#ifdef CONFIG_MODULE_SIG -static int module_sig_check(struct load_info *info, int flags) -{ - int err = -ENODATA; - const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; - const char *reason; - const void *mod = info->hdr; - - /* - * Require flags == 0, as a module with version information - * removed is no longer the module that was signed - */ - if (flags == 0 && - info->len > markerlen && - memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { - /* We truncate the module to discard the signature */ - info->len -= markerlen; - err = mod_verify_sig(mod, info); - } - - switch (err) { - case 0: - info->sig_ok = true; - return 0; - - /* We don't permit modules to be loaded into trusted kernels - * without a valid signature on them, but if we're not - * enforcing, certain errors are non-fatal. - */ - case -ENODATA: - reason = "Loading of unsigned module"; - goto decide; - case -ENOPKG: - reason = "Loading of module with unsupported crypto"; - goto decide; - case -ENOKEY: - reason = "Loading of module with unavailable key"; - decide: - if (is_module_sig_enforced()) { - pr_notice("%s: %s is rejected\n", info->name, reason); - return -EKEYREJECTED; - } - - return security_locked_down(LOCKDOWN_MODULE_SIGNATURE); - - /* All other errors are fatal, including nomem, unparseable - * signatures and signature check failures - even if signatures - * aren't required. - */ - default: - return err; - } -} -#else /* !CONFIG_MODULE_SIG */ -static int module_sig_check(struct load_info *info, int flags) -{ - return 0; -} -#endif /* !CONFIG_MODULE_SIG */ - -/* Sanity checks against invalid binaries, wrong arch, weird elf version. */ -static int elf_header_check(struct load_info *info) -{ - if (info->len < sizeof(*(info->hdr))) - return -ENOEXEC; - - if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0 - || info->hdr->e_type != ET_REL - || !elf_check_arch(info->hdr) - || info->hdr->e_shentsize != sizeof(Elf_Shdr)) - return -ENOEXEC; - - if (info->hdr->e_shoff >= info->len - || (info->hdr->e_shnum * sizeof(Elf_Shdr) > - info->len - info->hdr->e_shoff)) - return -ENOEXEC; - - return 0; -} - -#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; -} - -#ifdef CONFIG_LIVEPATCH -static int check_modinfo_livepatch(struct module *mod, struct load_info *info) -{ - if (get_modinfo(info, "livepatch")) { - mod->klp = true; - add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); - pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n", - mod->name); - } - - return 0; -} -#else /* !CONFIG_LIVEPATCH */ -static int check_modinfo_livepatch(struct module *mod, struct load_info *info) -{ - if (get_modinfo(info, "livepatch")) { - pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", - mod->name); - return -ENOEXEC; - } - - return 0; -} -#endif /* CONFIG_LIVEPATCH */ - -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); - if (err) - return err; - - /* Suck in entire file: we'll want most of it. */ - info->hdr = __vmalloc(info->len, - GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL); - if (!info->hdr) - return -ENOMEM; - - if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { - vfree(info->hdr); - return -EFAULT; - } - - return 0; -} - -static void free_copy(struct load_info *info) -{ - 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]; - if (shdr->sh_type != SHT_NOBITS - && info->len < shdr->sh_offset + shdr->sh_size) { - pr_err("Module len %lu truncated\n", info->len); - return -ENOEXEC; - } - - /* Mark all sections sh_addr with their address in the - temporary image. */ - shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; - -#ifndef CONFIG_MODULE_UNLOAD - /* Don't load .exit sections */ - if (module_exit_section(info->secstrings+shdr->sh_name)) - shdr->sh_flags &= ~(unsigned long)SHF_ALLOC; -#endif - } - - /* 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; - - /* Set up the convenience variables */ - info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; - info->secstrings = (void *)info->hdr - + info->sechdrs[info->hdr->e_shstrndx].sh_offset; - - /* 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")); - - 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"); - mod->gpl_future_syms = section_objs(info, - "__ksymtab_gpl_future", - sizeof(*mod->gpl_future_syms), - &mod->num_gpl_future_syms); - mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future"); - -#ifdef CONFIG_UNUSED_SYMBOLS - mod->unused_syms = section_objs(info, "__ksymtab_unused", - sizeof(*mod->unused_syms), - &mod->num_unused_syms); - mod->unused_crcs = section_addr(info, "__kcrctab_unused"); - mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl", - sizeof(*mod->unused_gpl_syms), - &mod->num_unused_gpl_syms); - mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl"); -#endif -#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 - -#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_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 - 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, "__verbose", - 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; - - /* 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 - 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) - || (mod->num_gpl_future_syms && !mod->gpl_future_crcs) -#ifdef CONFIG_UNUSED_SYMBOLS - || (mod->num_unused_syms && !mod->unused_crcs) - || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) -#endif - ) { - return try_to_force_load(mod, - "no versions for exported symbols"); - } -#endif - return 0; -} - -static void flush_module_icache(const struct module *mod) -{ - mm_segment_t old_fs; - - /* flush the icache in correct context */ - old_fs = get_fs(); - set_fs(KERNEL_DS); - - /* - * 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); - - set_fs(old_fs); -} - -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); - - /* 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); -} - -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); - } -} - -static int __init modules_wq_init(void) -{ - INIT_WORK(&init_free_wq, do_free_init); - init_llist_head(&init_free_list); - return 0; -} -module_init(modules_wq_init); - -/* - * 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; - - /* - * We want to find out whether @mod uses async during init. Clear - * PF_USED_ASYNC. async_schedule*() will set it. - */ - current->flags &= ~PF_USED_ASYNC; - - 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); - - /* - * We need to finish all async code before the module init sequence - * is done. This has potential to deadlock. For example, a newly - * detected block device can trigger request_module() of the - * default iosched from async probing task. Once userland helper - * reaches here, async_synchronize_full() will wait on the async - * task waiting on request_module() and deadlock. - * - * This deadlock is avoided by perfomring async_synchronize_full() - * iff module init queued any async jobs. This isn't a full - * solution as it will deadlock the same if module loading from - * async jobs nests more than once; however, due to the various - * constraints, this hack seems to be the best option for now. - * Please refer to the following thread for details. - * - * http://thread.gmane.org/gmane.linux.kernel/1420814 - */ - if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC)) - 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; - /* - * 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); - - 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: - 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; - - blocking_notifier_call_chain(&module_notify_list, - MODULE_STATE_COMING, mod); - return 0; -} - -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) { - 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; -} - -/* 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; - - err = elf_header_check(info); - if (err) - goto free_copy; - - err = setup_load_info(info, flags); - if (err) - goto free_copy; - - if (blacklisted(info->name)) { - err = -EPERM; - goto free_copy; - } - - err = module_sig_check(info, flags); - if (err) - 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); - - /* 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; - } - - 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; - - /* 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); - - /* 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: - /* 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: - 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->core_layout.base, mod->core_layout.size); - - module_deallocate(mod, info); - free_copy: - free_copy(info); - 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 = { }; - loff_t size; - void *hdr; - 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)) - return -EINVAL; - - err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX, - READING_MODULE); - if (err) - return err; - info.hdr = hdr; - info.len = size; - - 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); -} - -#ifdef CONFIG_KALLSYMS -/* - * This ignores the intensely annoying "mapping symbols" found - * in ARM ELF files: $a, $t and $d. - */ -static inline int is_arm_mapping_symbol(const char *str) -{ - if (str[0] == '.' && str[1] == 'L') - return true; - return str[0] == '$' && strchr("axtd", str[1]) - && (str[2] == '\0' || str[2] == '.'); -} - -static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum) -{ - return kallsyms->strtab + kallsyms->symtab[symnum].st_name; -} - -/* - * Given a module and address, find the corresponding symbol and return its name - * while providing its size and offset if needed. - */ -static const char *find_kallsyms_symbol(struct module *mod, - unsigned long addr, - unsigned long *size, - unsigned long *offset) -{ - unsigned int i, best = 0; - unsigned long nextval, bestval; - struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); - - /* At worse, next value is at end of module */ - if (within_module_init(addr, mod)) - nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size; - else - nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size; - - bestval = kallsyms_symbol_value(&kallsyms->symtab[best]); - - /* Scan for closest preceding symbol, and next symbol. (ELF - starts real symbols at 1). */ - for (i = 1; i < kallsyms->num_symtab; i++) { - const Elf_Sym *sym = &kallsyms->symtab[i]; - unsigned long thisval = kallsyms_symbol_value(sym); - - if (sym->st_shndx == SHN_UNDEF) - continue; - - /* We ignore unnamed symbols: they're uninformative - * and inserted at a whim. */ - if (*kallsyms_symbol_name(kallsyms, i) == '\0' - || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i))) - continue; - - if (thisval <= addr && thisval > bestval) { - best = i; - bestval = thisval; - } - if (thisval > addr && thisval < nextval) - nextval = thisval; - } - - if (!best) - return NULL; - - if (size) - *size = nextval - bestval; - if (offset) - *offset = addr - bestval; - - return kallsyms_symbol_name(kallsyms, best); -} - -void * __weak dereference_module_function_descriptor(struct module *mod, - void *ptr) -{ - return ptr; -} - -/* For kallsyms to ask for address resolution. NULL means not found. Careful - * not to lock to avoid deadlock on oopses, simply disable preemption. */ -const char *module_address_lookup(unsigned long addr, - unsigned long *size, - unsigned long *offset, - char **modname, - char *namebuf) -{ - const char *ret = NULL; - struct module *mod; - - preempt_disable(); - mod = __module_address(addr); - if (mod) { - if (modname) - *modname = mod->name; - - ret = find_kallsyms_symbol(mod, addr, size, offset); - } - /* Make a copy in here where it's safe */ - if (ret) { - strncpy(namebuf, ret, KSYM_NAME_LEN - 1); - ret = namebuf; - } - preempt_enable(); - - return ret; -} - -int lookup_module_symbol_name(unsigned long addr, char *symname) -{ - struct module *mod; - - preempt_disable(); - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - if (within_module(addr, mod)) { - const char *sym; - - sym = find_kallsyms_symbol(mod, addr, NULL, NULL); - if (!sym) - goto out; - - strlcpy(symname, sym, KSYM_NAME_LEN); - preempt_enable(); - return 0; - } - } -out: - preempt_enable(); - return -ERANGE; -} - -int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, - unsigned long *offset, char *modname, char *name) -{ - struct module *mod; - - preempt_disable(); - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - if (within_module(addr, mod)) { - const char *sym; - - sym = find_kallsyms_symbol(mod, addr, size, offset); - if (!sym) - goto out; - if (modname) - strlcpy(modname, mod->name, MODULE_NAME_LEN); - if (name) - strlcpy(name, sym, KSYM_NAME_LEN); - preempt_enable(); - return 0; - } - } -out: - preempt_enable(); - return -ERANGE; -} - -int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, - char *name, char *module_name, int *exported) -{ - struct module *mod; - - preempt_disable(); - list_for_each_entry_rcu(mod, &modules, list) { - struct mod_kallsyms *kallsyms; - - if (mod->state == MODULE_STATE_UNFORMED) - continue; - kallsyms = rcu_dereference_sched(mod->kallsyms); - if (symnum < kallsyms->num_symtab) { - const Elf_Sym *sym = &kallsyms->symtab[symnum]; - - *value = kallsyms_symbol_value(sym); - *type = kallsyms->typetab[symnum]; - strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN); - strlcpy(module_name, mod->name, MODULE_NAME_LEN); - *exported = is_exported(name, *value, mod); - preempt_enable(); - return 0; - } - symnum -= kallsyms->num_symtab; - } - preempt_enable(); - return -ERANGE; -} - -/* Given a module and name of symbol, find and return the symbol's value */ -static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name) -{ - unsigned int i; - struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); - - for (i = 0; i < kallsyms->num_symtab; i++) { - const Elf_Sym *sym = &kallsyms->symtab[i]; - - if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 && - sym->st_shndx != SHN_UNDEF) - return kallsyms_symbol_value(sym); - } - return 0; -} - -/* Look for this name: can be of form module:name. */ -unsigned long module_kallsyms_lookup_name(const char *name) -{ - struct module *mod; - char *colon; - unsigned long ret = 0; - - /* Don't lock: we're in enough trouble already. */ - preempt_disable(); - if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) { - if ((mod = find_module_all(name, colon - name, false)) != NULL) - ret = find_kallsyms_symbol_value(mod, colon+1); - } else { - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - if ((ret = find_kallsyms_symbol_value(mod, name)) != 0) - break; - } - } - preempt_enable(); - return ret; -} - -int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, - struct module *, unsigned long), - void *data) -{ - struct module *mod; - unsigned int i; - int ret; - - module_assert_mutex(); - - list_for_each_entry(mod, &modules, list) { - /* We hold module_mutex: no need for rcu_dereference_sched */ - struct mod_kallsyms *kallsyms = mod->kallsyms; - - if (mod->state == MODULE_STATE_UNFORMED) - continue; - for (i = 0; i < kallsyms->num_symtab; i++) { - const Elf_Sym *sym = &kallsyms->symtab[i]; - - if (sym->st_shndx == SHN_UNDEF) - continue; - - ret = fn(data, kallsyms_symbol_name(kallsyms, i), - mod, kallsyms_symbol_value(sym)); - if (ret != 0) - return ret; - } - } - return 0; -} -#endif /* CONFIG_KALLSYMS */ - -/* Maximum number of characters written by module_flags() */ -#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) - -/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */ -static char *module_flags(struct module *mod, char *buf) -{ - int bx = 0; - - BUG_ON(mod->state == MODULE_STATE_UNFORMED); - if (mod->taints || - mod->state == MODULE_STATE_GOING || - mod->state == MODULE_STATE_COMING) { - buf[bx++] = '('; - bx += module_flags_taint(mod, buf + bx); - /* Show a - for module-is-being-unloaded */ - if (mod->state == MODULE_STATE_GOING) - buf[bx++] = '-'; - /* Show a + for module-is-being-loaded */ - if (mod->state == MODULE_STATE_COMING) - buf[bx++] = '+'; - buf[bx++] = ')'; - } - buf[bx] = '\0'; - - return buf; -} - -#ifdef CONFIG_PROC_FS -/* Called by the /proc file system to return a list of modules. */ -static void *m_start(struct seq_file *m, loff_t *pos) -{ - mutex_lock(&module_mutex); - return seq_list_start(&modules, *pos); -} - -static void *m_next(struct seq_file *m, void *p, loff_t *pos) -{ - return seq_list_next(p, &modules, pos); -} - -static void m_stop(struct seq_file *m, void *p) -{ - mutex_unlock(&module_mutex); -} - -static int m_show(struct seq_file *m, void *p) -{ - struct module *mod = list_entry(p, struct module, list); - char buf[MODULE_FLAGS_BUF_SIZE]; - void *value; - - /* We always ignore unformed modules. */ - if (mod->state == MODULE_STATE_UNFORMED) - return 0; - - seq_printf(m, "%s %u", - mod->name, mod->init_layout.size + mod->core_layout.size); - print_unload_info(m, mod); - - /* Informative for users. */ - seq_printf(m, " %s", - mod->state == MODULE_STATE_GOING ? "Unloading" : - mod->state == MODULE_STATE_COMING ? "Loading" : - "Live"); - /* Used by oprofile and other similar tools. */ - value = m->private ? NULL : mod->core_layout.base; - seq_printf(m, " 0x%px", value); - - /* Taints info */ - if (mod->taints) - seq_printf(m, " %s", module_flags(mod, buf)); - - seq_puts(m, "\n"); - return 0; -} - -/* Format: modulename size refcount deps address - - Where refcount is a number or -, and deps is a comma-separated list - of depends or -. -*/ -static const struct seq_operations modules_op = { - .start = m_start, - .next = m_next, - .stop = m_stop, - .show = m_show -}; - -/* - * This also sets the "private" pointer to non-NULL if the - * kernel pointers should be hidden (so you can just test - * "m->private" to see if you should keep the values private). - * - * We use the same logic as for /proc/kallsyms. - */ -static int modules_open(struct inode *inode, struct file *file) -{ - int err = seq_open(file, &modules_op); - - if (!err) { - struct seq_file *m = file->private_data; - m->private = kallsyms_show_value() ? NULL : (void *)8ul; - } - - return err; -} - -static const struct proc_ops modules_proc_ops = { - .proc_open = modules_open, - .proc_read = seq_read, - .proc_lseek = seq_lseek, - .proc_release = seq_release, -}; - -static int __init proc_modules_init(void) -{ - proc_create("modules", 0, NULL, &modules_proc_ops); - return 0; -} -module_init(proc_modules_init); -#endif - -/* 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; - - if (addr < module_addr_min || addr > module_addr_max) - return NULL; - - module_assert_mutex_or_preempt(); - - mod = mod_find(addr); - if (mod) { - BUG_ON(!within_module(addr, mod)); - if (mod->state == MODULE_STATE_UNFORMED) - mod = NULL; - } - return mod; -} -EXPORT_SYMBOL_GPL(__module_address); - -/* - * is_module_text_address - is this address inside module code? - * @addr: the address to check. - * - * See is_module_address() if you simply want to see if the address is - * anywhere in a module. See kernel_text_address() for testing if an - * address corresponds to kernel or module code. - */ -bool is_module_text_address(unsigned long addr) -{ - bool ret; - - preempt_disable(); - ret = __module_text_address(addr) != NULL; - preempt_enable(); - - return ret; -} - -/* - * __module_text_address - get the module whose code 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_text_address(unsigned long addr) -{ - struct module *mod = __module_address(addr); - if (mod) { - /* Make sure it's within the text section. */ - if (!within(addr, mod->init_layout.base, mod->init_layout.text_size) - && !within(addr, mod->core_layout.base, mod->core_layout.text_size)) - mod = NULL; - } - return mod; -} -EXPORT_SYMBOL_GPL(__module_text_address); - -/* Don't grab lock, we're oopsing. */ -void print_modules(void) -{ - struct module *mod; - char buf[MODULE_FLAGS_BUF_SIZE]; - - printk(KERN_DEFAULT "Modules linked in:"); - /* Most callers should already have preempt disabled, but make sure */ - preempt_disable(); - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - pr_cont(" %s%s", mod->name, module_flags(mod, buf)); - } - preempt_enable(); - if (last_unloaded_module[0]) - pr_cont(" [last unloaded: %s]", last_unloaded_module); - pr_cont("\n"); -} - -#ifdef CONFIG_MODVERSIONS -/* Generate the signature for all relevant module structures here. - * If these change, we don't want to try to parse the module. */ -void module_layout(struct module *mod, - struct modversion_info *ver, - struct kernel_param *kp, - struct kernel_symbol *ks, - struct tracepoint * const *tp) -{ -} -EXPORT_SYMBOL(module_layout); -#endif |