| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2002 Richard Henderson |
| * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. |
| */ |
| |
| #define INCLUDE_VERMAGIC |
| |
| #include <linux/export.h> |
| #include <linux/extable.h> |
| #include <linux/moduleloader.h> |
| #include <linux/module_signature.h> |
| #include <linux/trace_events.h> |
| #include <linux/init.h> |
| #include <linux/kallsyms.h> |
| #include <linux/buildid.h> |
| #include <linux/file.h> |
| #include <linux/fs.h> |
| #include <linux/sysfs.h> |
| #include <linux/kernel.h> |
| #include <linux/kernel_read_file.h> |
| #include <linux/slab.h> |
| #include <linux/vmalloc.h> |
| #include <linux/elf.h> |
| #include <linux/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> |
| |
| #undef CREATE_TRACE_POINTS |
| #include <trace/hooks/module.h> |
| #include <trace/hooks/memory.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). |
| */ |
| static DEFINE_MUTEX(module_mutex); |
| static LIST_HEAD(modules); |
| |
| /* Work queue for freeing init sections in success case */ |
| static void do_free_init(struct work_struct *w); |
| static DECLARE_WORK(init_free_wq, do_free_init); |
| static LLIST_HEAD(init_free_list); |
| |
| #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_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 |
| } |
| |
| #if defined(CONFIG_MODULE_SIG) && !defined(CONFIG_MODULE_SIG_PROTECT) |
| static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); |
| module_param(sig_enforce, bool_enable_only, 0644); |
| |
| void set_module_sig_enforced(void) |
| { |
| sig_enforce = true; |
| } |
| #else |
| #define sig_enforce false |
| #endif |
| |
| /* |
| * 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); |
| |
| /* 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; |
| } |
| |
| /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */ |
| static unsigned int find_any_sec(const struct load_info *info, const char *name) |
| { |
| unsigned int i; |
| |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| Elf_Shdr *shdr = &info->sechdrs[i]; |
| if (strcmp(info->secstrings + shdr->sh_name, name) == 0) |
| return i; |
| } |
| return 0; |
| } |
| |
| /* |
| * Find a module section, or NULL. Fill in number of "objects" in section. |
| * Ignores SHF_ALLOC flag. |
| */ |
| static __maybe_unused void *any_section_objs(const struct load_info *info, |
| const char *name, |
| size_t object_size, |
| unsigned int *num) |
| { |
| unsigned int sec = find_any_sec(info, name); |
| |
| /* Section 0 has sh_addr 0 and sh_size 0. */ |
| *num = info->sechdrs[sec].sh_size / object_size; |
| return (void *)info->sechdrs[sec].sh_addr; |
| } |
| |
| /* Provided by the linker */ |
| extern const struct kernel_symbol __start___ksymtab[]; |
| extern const struct kernel_symbol __stop___ksymtab[]; |
| extern const struct kernel_symbol __start___ksymtab_gpl[]; |
| extern const struct kernel_symbol __stop___ksymtab_gpl[]; |
| extern const s32 __start___kcrctab[]; |
| extern const s32 __start___kcrctab_gpl[]; |
| |
| #ifndef CONFIG_MODVERSIONS |
| #define symversion(base, idx) NULL |
| #else |
| #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) |
| #endif |
| |
| struct symsearch { |
| const struct kernel_symbol *start, *stop; |
| const s32 *crcs; |
| enum mod_license { |
| NOT_GPL_ONLY, |
| GPL_ONLY, |
| } license; |
| }; |
| |
| struct find_symbol_arg { |
| /* Input */ |
| const char *name; |
| bool gplok; |
| bool warn; |
| |
| /* Output */ |
| struct module *owner; |
| const s32 *crc; |
| const struct kernel_symbol *sym; |
| enum mod_license license; |
| }; |
| |
| 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 && syms->license == GPL_ONLY) |
| return false; |
| fsa->owner = owner; |
| fsa->crc = symversion(syms->crcs, symnum); |
| fsa->sym = &syms->start[symnum]; |
| fsa->license = syms->license; |
| 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. |
| */ |
| static bool find_symbol(struct find_symbol_arg *fsa) |
| { |
| static const struct symsearch arr[] = { |
| { __start___ksymtab, __stop___ksymtab, __start___kcrctab, |
| NOT_GPL_ONLY }, |
| { __start___ksymtab_gpl, __stop___ksymtab_gpl, |
| __start___kcrctab_gpl, |
| GPL_ONLY }, |
| }; |
| struct module *mod; |
| unsigned int i; |
| |
| module_assert_mutex_or_preempt(); |
| |
| for (i = 0; i < ARRAY_SIZE(arr); i++) |
| if (find_exported_symbol_in_section(&arr[i], NULL, fsa)) |
| return true; |
| |
| list_for_each_entry_rcu(mod, &modules, list, |
| lockdep_is_held(&module_mutex)) { |
| struct symsearch arr[] = { |
| { mod->syms, mod->syms + mod->num_syms, mod->crcs, |
| NOT_GPL_ONLY }, |
| { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, |
| mod->gpl_crcs, |
| GPL_ONLY }, |
| }; |
| |
| if (mod->state == MODULE_STATE_UNFORMED) |
| continue; |
| |
| for (i = 0; i < ARRAY_SIZE(arr); i++) |
| if (find_exported_symbol_in_section(&arr[i], mod, fsa)) |
| return true; |
| } |
| |
| pr_debug("Failed to find symbol %s\n", fsa->name); |
| return false; |
| } |
| |
| /* |
| * Search for module by name: must hold module_mutex (or preempt disabled |
| * for read-only access). |
| */ |
| 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) |
| { |
| return find_module_all(name, strlen(name), false); |
| } |
| |
| #ifdef CONFIG_SMP |
| |
| static inline void __percpu *mod_percpu(struct module *mod) |
| { |
| return mod->percpu; |
| } |
| |
| static int percpu_modalloc(struct module *mod, struct load_info *info) |
| { |
| Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; |
| unsigned long align = pcpusec->sh_addralign; |
| |
| if (!pcpusec->sh_size) |
| return 0; |
| |
| if (align > PAGE_SIZE) { |
| pr_warn("%s: per-cpu alignment %li > %li\n", |
| mod->name, align, PAGE_SIZE); |
| align = PAGE_SIZE; |
| } |
| |
| mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); |
| if (!mod->percpu) { |
| pr_warn("%s: Could not allocate %lu bytes percpu data\n", |
| mod->name, (unsigned long)pcpusec->sh_size); |
| return -ENOMEM; |
| } |
| mod->percpu_size = pcpusec->sh_size; |
| return 0; |
| } |
| |
| static void percpu_modfree(struct module *mod) |
| { |
| free_percpu(mod->percpu); |
| } |
| |
| static unsigned int find_pcpusec(struct load_info *info) |
| { |
| return find_sec(info, ".data..percpu"); |
| } |
| |
| static void percpu_modcopy(struct module *mod, |
| const void *from, unsigned long size) |
| { |
| int cpu; |
| |
| for_each_possible_cpu(cpu) |
| memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); |
| } |
| |
| bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) |
| { |
| struct module *mod; |
| unsigned int cpu; |
| |
| preempt_disable(); |
| |
| list_for_each_entry_rcu(mod, &modules, list) { |
| if (mod->state == MODULE_STATE_UNFORMED) |
| continue; |
| if (!mod->percpu_size) |
| continue; |
| for_each_possible_cpu(cpu) { |
| void *start = per_cpu_ptr(mod->percpu, cpu); |
| void *va = (void *)addr; |
| |
| if (va >= start && va < start + mod->percpu_size) { |
| if (can_addr) { |
| *can_addr = (unsigned long) (va - start); |
| *can_addr += (unsigned long) |
| per_cpu_ptr(mod->percpu, |
| get_boot_cpu_id()); |
| } |
| preempt_enable(); |
| return true; |
| } |
| } |
| } |
| |
| preempt_enable(); |
| return false; |
| } |
| |
| /** |
| * is_module_percpu_address() - test whether address is from module static percpu |
| * @addr: address to test |
| * |
| * Test whether @addr belongs to module static percpu area. |
| * |
| * Return: %true if @addr is from module static percpu area |
| */ |
| bool is_module_percpu_address(unsigned long addr) |
| { |
| return __is_module_percpu_address(addr, NULL); |
| } |
| |
| #else /* ... !CONFIG_SMP */ |
| |
| static inline void __percpu *mod_percpu(struct module *mod) |
| { |
| return NULL; |
| } |
| static int percpu_modalloc(struct module *mod, struct load_info *info) |
| { |
| /* UP modules shouldn't have this section: ENOMEM isn't quite right */ |
| if (info->sechdrs[info->index.pcpu].sh_size != 0) |
| return -ENOMEM; |
| return 0; |
| } |
| static inline void percpu_modfree(struct module *mod) |
| { |
| } |
| static unsigned int find_pcpusec(struct load_info *info) |
| { |
| return 0; |
| } |
| static inline void percpu_modcopy(struct module *mod, |
| const void *from, unsigned long size) |
| { |
| /* pcpusec should be 0, and size of that section should be 0. */ |
| BUG_ON(size != 0); |
| } |
| bool is_module_percpu_address(unsigned long addr) |
| { |
| return false; |
| } |
| |
| bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) |
| { |
| return false; |
| } |
| |
| #endif /* CONFIG_SMP */ |
| |
| #define MODINFO_ATTR(field) \ |
| static void setup_modinfo_##field(struct module *mod, const char *s) \ |
| { \ |
| mod->field = kstrdup(s, GFP_KERNEL); \ |
| } \ |
| static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ |
| struct module_kobject *mk, char *buffer) \ |
| { \ |
| return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ |
| } \ |
| static int modinfo_##field##_exists(struct module *mod) \ |
| { \ |
| return mod->field != NULL; \ |
| } \ |
| static void free_modinfo_##field(struct module *mod) \ |
| { \ |
| kfree(mod->field); \ |
| mod->field = NULL; \ |
| } \ |
| static struct module_attribute modinfo_##field = { \ |
| .attr = { .name = __stringify(field), .mode = 0444 }, \ |
| .show = show_modinfo_##field, \ |
| .setup = setup_modinfo_##field, \ |
| .test = modinfo_##field##_exists, \ |
| .free = free_modinfo_##field, \ |
| }; |
| |
| MODINFO_ATTR(version); |
| MODINFO_ATTR(srcversion); |
| MODINFO_ATTR(scmversion); |
| |
| 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() */ |
| static int ref_module(struct module *a, struct module *b) |
| { |
| int err; |
| |
| if (b == NULL || already_uses(a, b)) |
| return 0; |
| |
| /* If module isn't available, we fail. */ |
| err = strong_try_module_get(b); |
| if (err) |
| return err; |
| |
| err = add_module_usage(a, b); |
| if (err) { |
| module_put(b); |
| return err; |
| } |
| return 0; |
| } |
| |
| /* Clear the unload stuff of the module. */ |
| static void module_unload_free(struct module *mod) |
| { |
| struct module_use *use, *tmp; |
| |
| mutex_lock(&module_mutex); |
| list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { |
| struct module *i = use->target; |
| pr_debug("%s unusing %s\n", mod->name, i->name); |
| module_put(i); |
| list_del(&use->source_list); |
| list_del(&use->target_list); |
| kfree(use); |
| } |
| mutex_unlock(&module_mutex); |
| } |
| |
| #ifdef CONFIG_MODULE_FORCE_UNLOAD |
| static inline int try_force_unload(unsigned int flags) |
| { |
| int ret = (flags & O_TRUNC); |
| if (ret) |
| add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); |
| return ret; |
| } |
| #else |
| static inline int try_force_unload(unsigned int flags) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_MODULE_FORCE_UNLOAD */ |
| |
| /* Try to release refcount of module, 0 means success. */ |
| static int try_release_module_ref(struct module *mod) |
| { |
| int ret; |
| |
| /* Try to decrement refcnt which we set at loading */ |
| ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); |
| BUG_ON(ret < 0); |
| if (ret) |
| /* Someone can put this right now, recover with checking */ |
| ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); |
| |
| return ret; |
| } |
| |
| static int try_stop_module(struct module *mod, int flags, int *forced) |
| { |
| /* If it's not unused, quit unless we're forcing. */ |
| if (try_release_module_ref(mod) != 0) { |
| *forced = try_force_unload(flags); |
| if (!(*forced)) |
| return -EWOULDBLOCK; |
| } |
| |
| /* Mark it as dying. */ |
| mod->state = MODULE_STATE_GOING; |
| |
| return 0; |
| } |
| |
| /** |
| * module_refcount() - return the refcount or -1 if unloading |
| * @mod: the module we're checking |
| * |
| * Return: |
| * -1 if the module is in the process of unloading |
| * otherwise the number of references in the kernel to the module |
| */ |
| int module_refcount(struct module *mod) |
| { |
| return atomic_read(&mod->refcnt) - MODULE_REF_BASE; |
| } |
| EXPORT_SYMBOL(module_refcount); |
| |
| /* This exists whether we can unload or not */ |
| static void free_module(struct module *mod); |
| |
| SYSCALL_DEFINE2(delete_module, const char __user *, name_user, |
| unsigned int, flags) |
| { |
| struct module *mod; |
| char name[MODULE_NAME_LEN]; |
| 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 find_symbol_arg fsa = { |
| .name = symbol, |
| .gplok = true, |
| }; |
| |
| preempt_disable(); |
| BUG_ON(!find_symbol(&fsa)); |
| module_put(fsa.owner); |
| preempt_enable(); |
| } |
| EXPORT_SYMBOL(__symbol_put); |
| |
| /* Note this assumes addr is a function, which it currently always is. */ |
| void symbol_put_addr(void *addr) |
| { |
| struct module *modaddr; |
| unsigned long a = (unsigned long)dereference_function_descriptor(addr); |
| |
| if (core_kernel_text(a)) |
| return; |
| |
| /* |
| * Even though we hold a reference on the module; we still need to |
| * disable preemption in order to safely traverse the data structure. |
| */ |
| preempt_disable(); |
| modaddr = __module_text_address(a); |
| BUG_ON(!modaddr); |
| module_put(modaddr); |
| preempt_enable(); |
| } |
| EXPORT_SYMBOL_GPL(symbol_put_addr); |
| |
| static ssize_t show_refcnt(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| return sprintf(buffer, "%i\n", module_refcount(mk->mod)); |
| } |
| |
| static struct module_attribute modinfo_refcnt = |
| __ATTR(refcnt, 0444, show_refcnt, NULL); |
| |
| void __module_get(struct module *module) |
| { |
| if (module) { |
| preempt_disable(); |
| atomic_inc(&module->refcnt); |
| trace_module_get(module, _RET_IP_); |
| preempt_enable(); |
| } |
| } |
| EXPORT_SYMBOL(__module_get); |
| |
| bool try_module_get(struct module *module) |
| { |
| bool ret = true; |
| |
| if (module) { |
| preempt_disable(); |
| /* Note: here, we can fail to get a reference */ |
| if (likely(module_is_live(module) && |
| atomic_inc_not_zero(&module->refcnt) != 0)) |
| trace_module_get(module, _RET_IP_); |
| else |
| ret = false; |
| |
| preempt_enable(); |
| } |
| return ret; |
| } |
| EXPORT_SYMBOL(try_module_get); |
| |
| void module_put(struct module *module) |
| { |
| int ret; |
| |
| if (module) { |
| preempt_disable(); |
| ret = atomic_dec_if_positive(&module->refcnt); |
| WARN_ON(ret < 0); /* Failed to put refcount */ |
| trace_module_put(module, _RET_IP_); |
| preempt_enable(); |
| } |
| } |
| EXPORT_SYMBOL(module_put); |
| |
| #else /* !CONFIG_MODULE_UNLOAD */ |
| static inline void 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) |
| { |
| } |
| |
| static int ref_module(struct module *a, struct module *b) |
| { |
| return strong_try_module_get(b); |
| } |
| |
| static inline int module_unload_init(struct module *mod) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_MODULE_UNLOAD */ |
| |
| 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_scmversion, |
| &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) |
| { |
| struct find_symbol_arg fsa = { |
| .name = "module_layout", |
| .gplok = true, |
| }; |
| |
| /* |
| * 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(&fsa)) { |
| preempt_enable(); |
| BUG(); |
| } |
| preempt_enable(); |
| return check_version(info, "module_layout", mod, fsa.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; |
| } |
| |
| static bool inherit_taint(struct module *mod, struct module *owner, const char *name) |
| { |
| if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) |
| return true; |
| |
| if (mod->using_gplonly_symbols) { |
| pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n", |
| mod->name, name, owner->name); |
| return false; |
| } |
| |
| if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) { |
| pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n", |
| mod->name, name, owner->name); |
| set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints); |
| } |
| return true; |
| } |
| |
| /* Resolve a symbol for this module. I.e. if we find one, record usage. */ |
| static const struct kernel_symbol *resolve_symbol(struct module *mod, |
| const struct load_info *info, |
| const char *name, |
| char ownername[]) |
| { |
| struct find_symbol_arg fsa = { |
| .name = name, |
| .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), |
| .warn = true, |
| }; |
| int err; |
| |
| /* |
| * The module_mutex should not be a heavily contended lock; |
| * if we get the occasional sleep here, we'll go an extra iteration |
| * in the wait_event_interruptible(), which is harmless. |
| */ |
| sched_annotate_sleep(); |
| mutex_lock(&module_mutex); |
| if (!find_symbol(&fsa)) |
| goto unlock; |
| |
| if (fsa.license == GPL_ONLY) |
| mod->using_gplonly_symbols = true; |
| |
| if (!inherit_taint(mod, fsa.owner, name)) { |
| fsa.sym = NULL; |
| goto getname; |
| } |
| |
| if (!check_version(info, name, mod, fsa.crc)) { |
| fsa.sym = ERR_PTR(-EINVAL); |
| goto getname; |
| } |
| |
| err = verify_namespace_is_imported(info, fsa.sym, mod); |
| if (err) { |
| fsa.sym = ERR_PTR(err); |
| goto getname; |
| } |
| |
| err = ref_module(mod, fsa.owner); |
| if (err) { |
| fsa.sym = ERR_PTR(err); |
| goto getname; |
| } |
| |
| getname: |
| /* We must make copy under the lock if we failed to get ref. */ |
| strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN); |
| unlock: |
| mutex_unlock(&module_mutex); |
| return fsa.sym; |
| } |
| |
| static const struct kernel_symbol * |
| resolve_symbol_wait(struct module *mod, |
| const struct load_info *info, |
| const char *name) |
| { |
| const struct kernel_symbol *ksym; |
| char owner[MODULE_NAME_LEN]; |
| |
| if (wait_event_interruptible_timeout(module_wq, |
| !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) |
| || PTR_ERR(ksym) != -EBUSY, |
| 30 * HZ) <= 0) { |
| pr_warn("%s: gave up waiting for init of module %s.\n", |
| mod->name, owner); |
| } |
| return ksym; |
| } |
| |
| #ifdef CONFIG_KALLSYMS |
| static inline bool sect_empty(const Elf_Shdr *sect) |
| { |
| return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; |
| } |
| #endif |
| |
| /* |
| * /sys/module/foo/sections stuff |
| * J. Corbet <corbet@lwn.net> |
| */ |
| #ifdef CONFIG_SYSFS |
| |
| #ifdef CONFIG_KALLSYMS |
| struct module_sect_attr { |
| struct bin_attribute battr; |
| unsigned long address; |
| }; |
| |
| struct module_sect_attrs { |
| struct attribute_group grp; |
| unsigned int nsections; |
| struct module_sect_attr attrs[]; |
| }; |
| |
| #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4)) |
| static ssize_t module_sect_read(struct file *file, struct kobject *kobj, |
| struct bin_attribute *battr, |
| char *buf, loff_t pos, size_t count) |
| { |
| struct module_sect_attr *sattr = |
| container_of(battr, struct module_sect_attr, battr); |
| char bounce[MODULE_SECT_READ_SIZE + 1]; |
| size_t wrote; |
| |
| if (pos != 0) |
| return -EINVAL; |
| |
| /* |
| * Since we're a binary read handler, we must account for the |
| * trailing NUL byte that sprintf will write: if "buf" is |
| * too small to hold the NUL, or the NUL is exactly the last |
| * byte, the read will look like it got truncated by one byte. |
| * Since there is no way to ask sprintf nicely to not write |
| * the NUL, we have to use a bounce buffer. |
| */ |
| wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n", |
| kallsyms_show_value(file->f_cred) |
| ? (void *)sattr->address : NULL); |
| count = min(count, wrote); |
| memcpy(buf, bounce, count); |
| |
| return count; |
| } |
| |
| 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].battr.attr.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 bin_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.bin_attrs[0])); |
| size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_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.bin_attrs = (void *)sect_attrs + size[0]; |
| |
| sect_attrs->nsections = 0; |
| sattr = §_attrs->attrs[0]; |
| gattr = §_attrs->grp.bin_attrs[0]; |
| for (i = 0; i < info->hdr->e_shnum; i++) { |
| Elf_Shdr *sec = &info->sechdrs[i]; |
| if (sect_empty(sec)) |
| continue; |
| sysfs_bin_attr_init(&sattr->battr); |
| sattr->address = sec->sh_addr; |
| sattr->battr.attr.name = |
| kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); |
| if (sattr->battr.attr.name == NULL) |
| goto out; |
| sect_attrs->nsections++; |
| sattr->battr.read = module_sect_read; |
| sattr->battr.size = MODULE_SECT_READ_SIZE; |
| sattr->battr.attr.mode = 0400; |
| *(gattr++) = &(sattr++)->battr; |
| } |
| *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[]; |
| }; |
| |
| 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].battr.attr.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); |
| |
| 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); |
| |
| 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); |
| } |
| |
| /* |
| * 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) |
| */ |
| |
| /* |
| * Since some arches are moving towards PAGE_KERNEL module allocations instead |
| * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the |
| * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of |
| * whether we are strict. |
| */ |
| #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX |
| 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); |
| } |
| |
| 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_x(const struct module *mod) { } |
| #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ |
| |
| #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); |
| } |
| |
| static 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); |
| } |
| |
| static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, |
| char *secstrings, struct module *mod) |
| { |
| const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR; |
| int i; |
| |
| for (i = 0; i < hdr->e_shnum; i++) { |
| if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) { |
| pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n", |
| mod->name, secstrings + sechdrs[i].sh_name, i); |
| return -ENOEXEC; |
| } |
| } |
| |
| return 0; |
| } |
| |
| #else /* !CONFIG_STRICT_MODULE_RWX */ |
| static void module_enable_nx(const struct module *mod) { } |
| static void module_enable_ro(const struct module *mod, bool after_init) {} |
| static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, |
| char *secstrings, struct module *mod) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_STRICT_MODULE_RWX */ |
| |
| #ifdef CONFIG_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) |
| { |
| } |
| |
| static void cfi_cleanup(struct module *mod); |
| |
| /* Free a module, remove from lists, etc. */ |
| static void free_module(struct module *mod) |
| { |
| trace_module_free(mod); |
| |
| mod_sysfs_teardown(mod); |
| |
| /* |
| * We leave it in list to prevent duplicate loads, but make sure |
| * that noone uses it while it's being deconstructed. |
| */ |
| mutex_lock(&module_mutex); |
| mod->state = MODULE_STATE_UNFORMED; |
| mutex_unlock(&module_mutex); |
| |
| /* Remove dynamic debug info */ |
| ddebug_remove_module(mod->name); |
| |
| /* Arch-specific cleanup. */ |
| module_arch_cleanup(mod); |
| |
| /* Module unload stuff */ |
| module_unload_free(mod); |
| |
| /* Free any allocated parameters. */ |
| destroy_params(mod->kp, mod->num_kp); |
| |
| if (is_livepatch_module(mod)) |
| free_module_elf(mod); |
| |
| /* Now we can delete it from the lists */ |
| mutex_lock(&module_mutex); |
| /* Unlink carefully: kallsyms could be walking list. */ |
| list_del_rcu(&mod->list); |
| mod_tree_remove(mod); |
| /* Remove this module from bug list, this uses list_del_rcu */ |
| module_bug_cleanup(mod); |
| /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ |
| synchronize_rcu(); |
| mutex_unlock(&module_mutex); |
| |
| /* Clean up CFI for the module. */ |
| cfi_cleanup(mod); |
| |
| /* This may be empty, but that's OK */ |
| module_arch_freeing_init(mod); |
| trace_android_vh_set_memory_rw((unsigned long)mod->init_layout.base, |
| (mod->init_layout.size)>>PAGE_SHIFT); |
| trace_android_vh_set_memory_nx((unsigned long)mod->init_layout.base, |
| (mod->init_layout.size)>>PAGE_SHIFT); |
| 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) */ |
| trace_android_vh_set_memory_rw((unsigned long)mod->core_layout.base, |
| (mod->core_layout.size)>>PAGE_SHIFT); |
| trace_android_vh_set_memory_nx((unsigned long)mod->core_layout.base, |
| (mod->core_layout.size)>>PAGE_SHIFT); |
| module_memfree(mod->core_layout.base); |
| } |
| |
| void *__symbol_get(const char *symbol) |
| { |
| struct find_symbol_arg fsa = { |
| .name = symbol, |
| .gplok = true, |
| .warn = true, |
| }; |
| |
| preempt_disable(); |
| if (!find_symbol(&fsa)) |
| goto fail; |
| if (fsa.license != GPL_ONLY) { |
| pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n", |
| symbol); |
| goto fail; |
| } |
| if (strong_try_module_get(fsa.owner)) |
| goto fail; |
| preempt_enable(); |
| return (void *)kernel_symbol_value(fsa.sym); |
| fail: |
| preempt_enable(); |
| return 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; |
| const struct kernel_symbol *s; |
| struct { |
| const struct kernel_symbol *sym; |
| unsigned int num; |
| } arr[] = { |
| { mod->syms, mod->num_syms }, |
| { mod->gpl_syms, mod->num_gpl_syms }, |
| }; |
| |
| for (i = 0; i < ARRAY_SIZE(arr); i++) { |
| for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { |
| struct find_symbol_arg fsa = { |
| .name = kernel_symbol_name(s), |
| .gplok = true, |
| }; |
| |
| if (!mod->sig_ok && gki_is_module_exported_symbol( |
| kernel_symbol_name(s))) { |
| pr_err("%s: exporting protected symbol(%s)\n", |
| mod->name, kernel_symbol_name(s)); |
| return -EACCES; |
| } |
| |
| if (find_symbol(&fsa)) { |
| pr_err("%s: exports duplicate symbol %s" |
| " (owned by %s)\n", |
| mod->name, kernel_symbol_name(s), |
| module_name(fsa.owner)); |
| return -ENOEXEC; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| static bool ignore_undef_symbol(Elf_Half emachine, const char *name) |
| { |
| /* |
| * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as |
| * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64. |
| * i386 has a similar problem but may not deserve a fix. |
| * |
| * If we ever have to ignore many symbols, consider refactoring the code to |
| * only warn if referenced by a relocation. |
| */ |
| if (emachine == EM_386 || emachine == EM_X86_64) |
| return !strcmp(name, "_GLOBAL_OFFSET_TABLE_"); |
| return false; |
| } |
| |
| /* Change all symbols so that st_value encodes the pointer directly. */ |
| static int simplify_symbols(struct module *mod, const struct load_info *info) |
| { |
| Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; |
| Elf_Sym *sym = (void *)symsec->sh_addr; |
| unsigned long secbase; |
| unsigned int i; |
| int ret = 0; |
| const struct kernel_symbol *ksym; |
| |
| for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { |
| const char *name = info->strtab + sym[i].st_name; |
| |
| switch (sym[i].st_shndx) { |
| case SHN_COMMON: |
| /* Ignore common symbols */ |
| if (!strncmp(name, "__gnu_lto", 9)) |
| break; |
| |
| /* |
| * We compiled with -fno-common. These are not |
| * supposed to happen. |
| */ |
| pr_debug("Common symbol: %s\n", name); |
| pr_warn("%s: please compile with -fno-common\n", |
| mod->name); |
| ret = -ENOEXEC; |
| break; |
| |
| case SHN_ABS: |
| /* Don't need to do anything */ |
| pr_debug("Absolute symbol: 0x%08lx\n", |
| (long)sym[i].st_value); |
| break; |
| |
| case SHN_LIVEPATCH: |
| /* Livepatch symbols are resolved by livepatch */ |
| break; |
| |
| case SHN_UNDEF: |
| if (!mod->sig_ok && |
| gki_is_module_protected_symbol(name)) { |
| pr_err("%s: is not an Android GKI signed module. It can not access protected symbol: %s\n", |
| mod->name, name); |
| return -EACCES; |
| } |
| |
| ksym = resolve_symbol_wait(mod, info, name); |
| /* Ok if resolved. */ |
| if (ksym && !IS_ERR(ksym)) { |
| sym[i].st_value = kernel_symbol_value(ksym); |
| break; |
| } |
| |
| /* Ok if weak or ignored. */ |
| if (!ksym && |
| (ELF_ST_BIND(sym[i].st_info) == STB_WEAK || |
| ignore_undef_symbol(info->hdr->e_machine, name))) |
| break; |
| |
| ret = PTR_ERR(ksym) ?: -ENOENT; |
| pr_warn("%s: Unknown symbol %s (err %d)\n", |
| mod->name, name, ret); |
| break; |
| |
| default: |
| /* Divert to percpu allocation if a percpu var. */ |
| if (sym[i].st_shndx == info->index.pcpu) |
| secbase = (unsigned long)mod_percpu(mod); |
| else |
| secbase = info->sechdrs[sym[i].st_shndx].sh_addr; |
| sym[i].st_value += secbase; |
| break; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int apply_relocations(struct module *mod, const struct load_info *info) |
| { |
| unsigned int i; |
| int err = 0; |
| |
| /* Now do relocations. */ |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| unsigned int infosec = info->sechdrs[i].sh_info; |
| |
| /* Not a valid relocation section? */ |
| if (infosec >= info->hdr->e_shnum) |
| continue; |
| |
| /* Don't bother with non-allocated sections */ |
| if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) |
| continue; |
| |
| if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) |
| err = klp_apply_section_relocs(mod, info->sechdrs, |
| info->secstrings, |
| info->strtab, |
| info->index.sym, i, |
| NULL); |
| else if (info->sechdrs[i].sh_type == SHT_REL) |
| err = apply_relocate(info->sechdrs, info->strtab, |
| info->index.sym, i, mod); |
| else if (info->sechdrs[i].sh_type == SHT_RELA) |
| err = apply_relocate_add(info->sechdrs, info->strtab, |
| info->index.sym, i, mod); |
| if (err < 0) |
| break; |
| } |
| return err; |
| } |
| |
| /* Additional bytes needed by arch in front of individual sections */ |
| unsigned int __weak arch_mod_section_prepend(struct module *mod, |
| unsigned int section) |
| { |
| /* default implementation just returns zero */ |
| return 0; |
| } |
| |
| /* Update size with this section: return offset. */ |
| 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; |
| } |
| |
| bool module_init_layout_section(const char *sname) |
| { |
| #ifndef CONFIG_MODULE_UNLOAD |
| if (module_exit_section(sname)) |
| return true; |
| #endif |
| return module_init_section(sname); |
| } |
| |
| /* |
| * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld |
| * might -- code, read-only data, read-write data, small data. Tally |
| * sizes, and place the offsets into sh_entsize fields: high bit means it |
| * belongs in init. |
| */ |
| static void layout_sections(struct module *mod, struct load_info *info) |
| { |
| static unsigned long const masks[][2] = { |
| /* |
| * NOTE: all executable code must be the first section |
| * in this array; otherwise modify the text_size |
| * finder in the two loops below |
| */ |
| { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, |
| { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, |
| { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, |
| { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, |
| { ARCH_SHF_SMALL | SHF_ALLOC, 0 } |
| }; |
| unsigned int m, i; |
| |
| for (i = 0; i < info->hdr->e_shnum; i++) |
| info->sechdrs[i].sh_entsize = ~0UL; |
| |
| pr_debug("Core section allocation order:\n"); |
| for (m = 0; m < ARRAY_SIZE(masks); ++m) { |
| for (i = 0; i < info->hdr->e_shnum; ++i) { |
| Elf_Shdr *s = &info->sechdrs[i]; |
| const char *sname = info->secstrings + s->sh_name; |
| |
| if ((s->sh_flags & masks[m][0]) != masks[m][0] |
| || (s->sh_flags & masks[m][1]) |
| || s->sh_entsize != ~0UL |
| || module_init_layout_section(sname)) |
| continue; |
| s->sh_entsize = 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 |
| || !module_init_layout_section(sname)) |
| 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 */ |
| |
| #if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) |
| static void init_build_id(struct module *mod, const struct load_info *info) |
| { |
| const Elf_Shdr *sechdr; |
| unsigned int i; |
| |
| for (i = 0; i < info->hdr->e_shnum; i++) { |
| sechdr = &info->sechdrs[i]; |
| if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE && |
| !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id, |
| sechdr->sh_size)) |
| break; |
| } |
| } |
| #else |
| static void init_build_id(struct module *mod, const struct load_info *info) |
| { |
| } |
| #endif |
| |
| static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num) |
| { |
| if (!debug) |
| return; |
| ddebug_add_module(debug, num, mod->name); |
| } |
| |
| static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) |
| { |
| if (debug) |
| ddebug_remove_module(mod->name); |
| } |
| |
| void * __weak module_alloc(unsigned long size) |
| { |
| return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, |
| GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, |
| NUMA_NO_NODE, __builtin_return_address(0)); |
| } |
| |
| bool __weak module_init_section(const char *name) |
| { |
| return strstarts(name, ".init"); |
| } |
| |
| bool __weak module_exit_section(const char *name) |
| { |
| return strstarts(name, ".exit"); |
| } |
| |
| #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); |
| if (!err) { |
| info->sig_ok = true; |
| return 0; |
| } |
| } |
| |
| /* |
| * We don't permit modules to be loaded into the trusted kernels |
| * without a valid signature on them, but if we're not enforcing, |
| * certain errors are non-fatal. |
| */ |
| switch (err) { |
| case -ENODATA: |
| reason = "unsigned module"; |
| break; |
| case -ENOPKG: |
| reason = "module with unsupported crypto"; |
| break; |
| case -ENOKEY: |
| reason = "module with unavailable key"; |
| break; |
| |
| default: |
| /* |
| * All other errors are fatal, including lack of memory, |
| * unparseable signatures, and signature check failures -- |
| * even if signatures aren't required. |
| */ |
| return err; |
| } |
| |
| if (is_module_sig_enforced()) { |
| pr_notice("Loading of %s is rejected\n", reason); |
| return -EKEYREJECTED; |
| } |
| |
| /* |
| * ANDROID: GKI: Do not prevent loading of unsigned modules; |
| * as all modules except GKI modules are not signed. |
| */ |
| #ifndef CONFIG_MODULE_SIG_PROTECT |
| return security_locked_down(LOCKDOWN_MODULE_SIGNATURE); |
| #else |
| return 0; |
| #endif |
| } |
| #else /* !CONFIG_MODULE_SIG */ |
| static int module_sig_check(struct load_info *info, int flags) |
| { |
| return 0; |
| } |
| #endif /* !CONFIG_MODULE_SIG */ |
| |
| static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr) |
| { |
| unsigned long secend; |
| |
| /* |
| * Check for both overflow and offset/size being |
| * too large. |
| */ |
| secend = shdr->sh_offset + shdr->sh_size; |
| if (secend < shdr->sh_offset || secend > info->len) |
| return -ENOEXEC; |
| |
| return 0; |
| } |
| |
| /* |
| * Sanity checks against invalid binaries, wrong arch, weird elf version. |
| * |
| * Also do basic validity checks against section offsets and sizes, the |
| * section name string table, and the indices used for it (sh_name). |
| */ |
| static int elf_validity_check(struct load_info *info) |
| { |
| unsigned int i; |
| Elf_Shdr *shdr, *strhdr; |
| int err; |
| |
| if (info->len < sizeof(*(info->hdr))) { |
| pr_err("Invalid ELF header len %lu\n", info->len); |
| goto no_exec; |
| } |
| |
| if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) { |
| pr_err("Invalid ELF header magic: != %s\n", ELFMAG); |
| goto no_exec; |
| } |
| if (info->hdr->e_type != ET_REL) { |
| pr_err("Invalid ELF header type: %u != %u\n", |
| info->hdr->e_type, ET_REL); |
| goto no_exec; |
| } |
| if (!elf_check_arch(info->hdr)) { |
| pr_err("Invalid architecture in ELF header: %u\n", |
| info->hdr->e_machine); |
| goto no_exec; |
| } |
| if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) { |
| pr_err("Invalid ELF section header size\n"); |
| goto no_exec; |
| } |
| |
| /* |
| * e_shnum is 16 bits, and sizeof(Elf_Shdr) is |
| * known and small. So e_shnum * sizeof(Elf_Shdr) |
| * will not overflow unsigned long on any platform. |
| */ |
| if (info->hdr->e_shoff >= info->len |
| || (info->hdr->e_shnum * sizeof(Elf_Shdr) > |
| info->len - info->hdr->e_shoff)) { |
| pr_err("Invalid ELF section header overflow\n"); |
| goto no_exec; |
| } |
| |
| info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; |
| |
| /* |
| * Verify if the section name table index is valid. |
| */ |
| if (info->hdr->e_shstrndx == SHN_UNDEF |
| || info->hdr->e_shstrndx >= info->hdr->e_shnum) { |
| pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n", |
| info->hdr->e_shstrndx, info->hdr->e_shstrndx, |
| info->hdr->e_shnum); |
| goto no_exec; |
| } |
| |
| strhdr = &info->sechdrs[info->hdr->e_shstrndx]; |
| err = validate_section_offset(info, strhdr); |
| if (err < 0) { |
| pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type); |
| return err; |
| } |
| |
| /* |
| * The section name table must be NUL-terminated, as required |
| * by the spec. This makes strcmp and pr_* calls that access |
| * strings in the section safe. |
| */ |
| info->secstrings = (void *)info->hdr + strhdr->sh_offset; |
| if (strhdr->sh_size == 0) { |
| pr_err("empty section name table\n"); |
| goto no_exec; |
| } |
| if (info->secstrings[strhdr->sh_size - 1] != '\0') { |
| pr_err("ELF Spec violation: section name table isn't null terminated\n"); |
| goto no_exec; |
| } |
| |
| /* |
| * The code assumes that section 0 has a length of zero and |
| * an addr of zero, so check for it. |
| */ |
| if (info->sechdrs[0].sh_type != SHT_NULL |
| || info->sechdrs[0].sh_size != 0 |
| || info->sechdrs[0].sh_addr != 0) { |
| pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n", |
| info->sechdrs[0].sh_type); |
| goto no_exec; |
| } |
| |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| shdr = &info->sechdrs[i]; |
| switch (shdr->sh_type) { |
| case SHT_NULL: |
| case SHT_NOBITS: |
| continue; |
| case SHT_SYMTAB: |
| if (shdr->sh_link == SHN_UNDEF |
| || shdr->sh_link >= info->hdr->e_shnum) { |
| pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n", |
| shdr->sh_link, shdr->sh_link, |
| info->hdr->e_shnum); |
| goto no_exec; |
| } |
| fallthrough; |
| default: |
| err = validate_section_offset(info, shdr); |
| if (err < 0) { |
| pr_err("Invalid ELF section in module (section %u type %u)\n", |
| i, shdr->sh_type); |
| return err; |
| } |
| |
| if (shdr->sh_flags & SHF_ALLOC) { |
| if (shdr->sh_name >= strhdr->sh_size) { |
| pr_err("Invalid ELF section name in module (section %u type %u)\n", |
| i, shdr->sh_type); |
| return -ENOEXEC; |
| } |
| } |
| break; |
| } |
| } |
| |
| return 0; |
| |
| no_exec: |
| return -ENOEXEC; |
| } |
| |
| #define COPY_CHUNK_SIZE (16*PAGE_SIZE) |
| |
| static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len) |
| { |
| do { |
| unsigned long n = min(len, COPY_CHUNK_SIZE); |
| |
| if (copy_from_user(dst, usrc, n) != 0) |
| return -EFAULT; |
| cond_resched(); |
| dst += n; |
| usrc += n; |
| len -= n; |
| } while (len); |
| return 0; |
| } |
| |
| #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, true); |
| if (err) |
| return err; |
| |
| /* Suck in entire file: we'll want most of it. */ |
| info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN); |
| if (!info->hdr) |
| return -ENOMEM; |
| |
| if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { |
| err = -EFAULT; |
| goto out; |
| } |
| |
| err = security_kernel_post_load_data((char *)info->hdr, info->len, |
| LOADING_MODULE, "init_module"); |
| out: |
| if (err) |
| vfree(info->hdr); |
| |
| return err; |
| } |
| |
| static void free_copy(struct load_info *info) |
| { |
| vfree(info->hdr); |
| } |
| |
| static int rewrite_section_headers(struct load_info *info, int flags) |
| { |
| unsigned int i; |
| |
| /* This should always be true, but let's be sure. */ |
| info->sechdrs[0].sh_addr = 0; |
| |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| Elf_Shdr *shdr = &info->sechdrs[i]; |
| |
| /* |
| * Mark all sections sh_addr with their address in the |
| * temporary image. |
| */ |
| shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; |
| |
| } |
| |
| /* Track but don't keep modinfo and version sections. */ |
| info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; |
| info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; |
| |
| return 0; |
| } |
| |
| /* |
| * Set up our basic convenience variables (pointers to section headers, |
| * search for module section index etc), and do some basic section |
| * verification. |
| * |
| * Set info->mod to the temporary copy of the module in info->hdr. The final one |
| * will be allocated in move_module(). |
| */ |
| static int setup_load_info(struct load_info *info, int flags) |
| { |
| unsigned int i; |
| |
| /* Try to find a name early so we can log errors with a module name */ |
| info->index.info = find_sec(info, ".modinfo"); |
| if (info->index.info) |
| info->name = get_modinfo(info, "name"); |
| |
| /* Find internal symbols and strings. */ |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| if (info->sechdrs[i].sh_type == SHT_SYMTAB) { |
| info->index.sym = i; |
| info->index.str = info->sechdrs[i].sh_link; |
| info->strtab = (char *)info->hdr |
| + info->sechdrs[info->index.str].sh_offset; |
| break; |
| } |
| } |
| |
| if (info->index.sym == 0) { |
| pr_warn("%s: module has no symbols (stripped?)\n", |
| info->name ?: "(missing .modinfo section or name field)"); |
| return -ENOEXEC; |
| } |
| |
| info->index.mod = find_sec(info, ".gnu.linkonce.this_module"); |
| if (!info->index.mod) { |
| pr_warn("%s: No module found in object\n", |
| info->name ?: "(missing .modinfo section or name field)"); |
| return -ENOEXEC; |
| } |
| /* This is temporary: point mod into copy of data. */ |
| info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset; |
| |
| /* |
| * If we didn't load the .modinfo 'name' field earlier, fall back to |
| * on-disk struct mod 'name' field. |
| */ |
| if (!info->name) |
| info->name = info->mod->name; |
| |
| if (flags & MODULE_INIT_IGNORE_MODVERSIONS) |
| info->index.vers = 0; /* Pretend no __versions section! */ |
| else |
| info->index.vers = find_sec(info, "__versions"); |
| |
| info->index.pcpu = find_pcpusec(info); |
| |
| return 0; |
| } |
| |
| static int check_modinfo(struct module *mod, struct load_info *info, int flags) |
| { |
| const char *modmagic = get_modinfo(info, "vermagic"); |
| int err; |
| |
| if (flags & MODULE_INIT_IGNORE_VERMAGIC) |
| modmagic = NULL; |
| |
| /* This is allowed: modprobe --force will invalidate it. */ |
| if (!modmagic) { |
| err = try_to_force_load(mod, "bad vermagic"); |
| if (err) |
| return err; |
| } else if (!same_magic(modmagic, vermagic, info->index.vers)) { |
| pr_err("%s: version magic '%s' should be '%s'\n", |
| info->name, modmagic, vermagic); |
| return -ENOEXEC; |
| } |
| |
| if (!get_modinfo(info, "intree")) { |
| if (!test_taint(TAINT_OOT_MODULE)) |
| pr_warn("%s: loading out-of-tree module taints kernel.\n", |
| mod->name); |
| add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); |
| } |
| |
| check_modinfo_retpoline(mod, info); |
| |
| if (get_modinfo(info, "staging")) { |
| add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); |
| pr_warn("%s: module is from the staging directory, the quality " |
| "is unknown, you have been warned.\n", mod->name); |
| } |
| |
| err = check_modinfo_livepatch(mod, info); |
| if (err) |
| return err; |
| |
| /* Set up license info based on the info section */ |
| set_license(mod, get_modinfo(info, "license")); |
| |
| return 0; |
| } |
| |
| static int find_module_sections(struct module *mod, struct load_info *info) |
| { |
| mod->kp = section_objs(info, "__param", |
| sizeof(*mod->kp), &mod->num_kp); |
| mod->syms = section_objs(info, "__ksymtab", |
| sizeof(*mod->syms), &mod->num_syms); |
| mod->crcs = section_addr(info, "__kcrctab"); |
| mod->gpl_syms = section_objs(info, "__ksymtab_gpl", |
| sizeof(*mod->gpl_syms), |
| &mod->num_gpl_syms); |
| mod->gpl_crcs = section_addr(info, "__kcrctab_gpl"); |
| |
| #ifdef CONFIG_CONSTRUCTORS |
| mod->ctors = section_objs(info, ".ctors", |
| sizeof(*mod->ctors), &mod->num_ctors); |
| if (!mod->ctors) |
| mod->ctors = section_objs(info, ".init_array", |
| sizeof(*mod->ctors), &mod->num_ctors); |
| else if (find_sec(info, ".init_array")) { |
| /* |
| * This shouldn't happen with same compiler and binutils |
| * building all parts of the module. |
| */ |
| pr_warn("%s: has both .ctors and .init_array.\n", |
| mod->name); |
| return -EINVAL; |
| } |
| #endif |
| |
| mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1, |
| &mod->noinstr_text_size); |
| |
| #ifdef CONFIG_TRACEPOINTS |
| mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", |
| sizeof(*mod->tracepoints_ptrs), |
| &mod->num_tracepoints); |
| #endif |
| #ifdef CONFIG_TREE_SRCU |
| mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs", |
| sizeof(*mod->srcu_struct_ptrs), |
| &mod->num_srcu_structs); |
| #endif |
| #ifdef CONFIG_BPF_EVENTS |
| mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map", |
| sizeof(*mod->bpf_raw_events), |
| &mod->num_bpf_raw_events); |
| #endif |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size); |
| #endif |
| #ifdef CONFIG_JUMP_LABEL |
| mod->jump_entries = section_objs(info, "__jump_table", |
| sizeof(*mod->jump_entries), |
| &mod->num_jump_entries); |
| #endif |
| #ifdef CONFIG_EVENT_TRACING |
| mod->trace_events = section_objs(info, "_ftrace_events", |
| sizeof(*mod->trace_events), |
| &mod->num_trace_events); |
| mod->trace_evals = section_objs(info, "_ftrace_eval_map", |
| sizeof(*mod->trace_evals), |
| &mod->num_trace_evals); |
| #endif |
| #ifdef CONFIG_TRACING |
| mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", |
| sizeof(*mod->trace_bprintk_fmt_start), |
| &mod->num_trace_bprintk_fmt); |
| #endif |
| #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
| /* sechdrs[0].sh_size is always zero */ |
| mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION, |
| sizeof(*mod->ftrace_callsites), |
| &mod->num_ftrace_callsites); |
| #endif |
| #ifdef CONFIG_FUNCTION_ERROR_INJECTION |
| mod->ei_funcs = section_objs(info, "_error_injection_whitelist", |
| sizeof(*mod->ei_funcs), |
| &mod->num_ei_funcs); |
| #endif |
| #ifdef CONFIG_KPROBES |
| mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1, |
| &mod->kprobes_text_size); |
| mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist", |
| sizeof(unsigned long), |
| &mod->num_kprobe_blacklist); |
| #endif |
| #ifdef CONFIG_PRINTK_INDEX |
| mod->printk_index_start = section_objs(info, ".printk_index", |
| sizeof(*mod->printk_index_start), |
| &mod->printk_index_size); |
| #endif |
| #ifdef CONFIG_HAVE_STATIC_CALL_INLINE |
| mod->static_call_sites = section_objs(info, ".static_call_sites", |
| sizeof(*mod->static_call_sites), |
| &mod->num_static_call_sites); |
| #endif |
| mod->extable = section_objs(info, "__ex_table", |
| sizeof(*mod->extable), &mod->num_exentries); |
| |
| if (section_addr(info, "__obsparm")) |
| pr_warn("%s: Ignoring obsolete parameters\n", mod->name); |
| |
| info->debug = section_objs(info, "__dyndbg", |
| sizeof(*info->debug), &info->num_debug); |
| |
| return 0; |
| } |
| |
| static int move_module(struct module *mod, struct load_info *info) |
| { |
| int i; |
| void *ptr; |
| |
| /* Do the allocs. */ |
| ptr = module_alloc(mod->core_layout.size); |
| /* |
| * The pointer to this block is stored in the module structure |
| * which is inside the block. Just mark it as not being a |
| * leak. |
| */ |
| kmemleak_not_leak(ptr); |
| if (!ptr) |
| return -ENOMEM; |
| |
| memset(ptr, 0, mod->core_layout.size); |
| mod->core_layout.base = ptr; |
| |
| if (mod->init_layout.size) { |
| ptr = module_alloc(mod->init_layout.size); |
| /* |
| * The pointer to this block is stored in the module structure |
| * which is inside the block. This block doesn't need to be |
| * scanned as it contains data and code that will be freed |
| * after the module is initialized. |
| */ |
| kmemleak_ignore(ptr); |
| if (!ptr) { |
| module_memfree(mod->core_layout.base); |
| return -ENOMEM; |
| } |
| memset(ptr, 0, mod->init_layout.size); |
| mod->init_layout.base = ptr; |
| } else |
| mod->init_layout.base = NULL; |
| |
| /* 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)) { |
| return try_to_force_load(mod, |
| "no versions for exported symbols"); |
| } |
| #endif |
| return 0; |
| } |
| |
| static void flush_module_icache(const struct module *mod) |
| { |
| /* |
| * Flush the instruction cache, since we've played with text. |
| * Do it before processing of module parameters, so the module |
| * can provide parameter accessor functions of its own. |
| */ |
| if (mod->init_layout.base) |
| flush_icache_range((unsigned long)mod->init_layout.base, |
| (unsigned long)mod->init_layout.base |
| + mod->init_layout.size); |
| flush_icache_range((unsigned long)mod->core_layout.base, |
| (unsigned long)mod->core_layout.base + mod->core_layout.size); |
| } |
| |
| int __weak module_frob_arch_sections(Elf_Ehdr *hdr, |
| Elf_Shdr *sechdrs, |
| char *secstrings, |
| struct module *mod) |
| { |
| return 0; |
| } |
| |
| /* module_blacklist is a comma-separated list of module names */ |
| static char *module_blacklist; |
| static bool blacklisted(const char *module_name) |
| { |
| const char *p; |
| size_t len; |
| |
| if (!module_blacklist) |
| return false; |
| |
| for (p = module_blacklist; *p; p += len) { |
| len = strcspn(p, ","); |
| if (strlen(module_name) == len && !memcmp(module_name, p, len)) |
| return true; |
| if (p[len] == ',') |
| len++; |
| } |
| return false; |
| } |
| core_param(module_blacklist, module_blacklist, charp, 0400); |
| |
| static struct module *layout_and_allocate(struct load_info *info, int flags) |
| { |
| struct module *mod; |
| unsigned int ndx; |
| int err; |
| |
| err = check_modinfo(info->mod, info, flags); |
| if (err) |
| return ERR_PTR(err); |
| |
| /* Allow arches to frob section contents and sizes. */ |
| err = module_frob_arch_sections(info->hdr, info->sechdrs, |
| info->secstrings, info->mod); |
| if (err < 0) |
| return ERR_PTR(err); |
| |
| err = module_enforce_rwx_sections(info->hdr, info->sechdrs, |
| info->secstrings, info->mod); |
| if (err < 0) |
| return ERR_PTR(err); |
| |
| /* We will do a special allocation for per-cpu sections later. */ |
| info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; |
| |
| /* |
| * Mark ro_after_init section with SHF_RO_AFTER_INIT so that |
| * layout_sections() can put it in the right place. |
| * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set. |
| */ |
| ndx = find_sec(info, ".data..ro_after_init"); |
| if (ndx) |
| info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; |
| /* |
| * Mark the __jump_table section as ro_after_init as well: these data |
| * structures are never modified, with the exception of entries that |
| * refer to code in the __init section, which are annotated as such |
| * at module load time. |
| */ |
| ndx = find_sec(info, "__jump_table"); |
| if (ndx) |
| info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; |
| |
| /* |
| * Determine total sizes, and put offsets in sh_entsize. For now |
| * this is done generically; there doesn't appear to be any |
| * special cases for the architectures. |
| */ |
| layout_sections(info->mod, info); |
| layout_symtab(info->mod, info); |
| |
| /* Allocate and move to the final place */ |
| err = move_module(info->mod, info); |
| if (err) |
| return ERR_PTR(err); |
| |
| /* Module has been copied to its final place now: return it. */ |
| mod = (void *)info->sechdrs[info->index.mod].sh_addr; |
| kmemleak_load_module(mod, info); |
| return mod; |
| } |
| |
| /* mod is no longer valid after this! */ |
| static void module_deallocate(struct module *mod, struct load_info *info) |
| { |
| percpu_modfree(mod); |
| module_arch_freeing_init(mod); |
| trace_android_vh_set_memory_rw((unsigned long)mod->init_layout.base, |
| (mod->init_layout.size)>>PAGE_SHIFT); |
| trace_android_vh_set_memory_nx((unsigned long)mod->init_layout.base, |
| (mod->init_layout.size)>>PAGE_SHIFT); |
| module_memfree(mod->init_layout.base); |
| trace_android_vh_set_memory_rw((unsigned long)mod->core_layout.base, |
| (mod->core_layout.size)>>PAGE_SHIFT); |
| trace_android_vh_set_memory_nx((unsigned long)mod->core_layout.base, |
| (mod->core_layout.size)>>PAGE_SHIFT); |
| 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 |
| || mod->state == MODULE_STATE_GOING; |
| 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); |
| } |
| } |
| |
| /* |
| * This is where the real work happens. |
| * |
| * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb |
| * helper command 'lx-symbols'. |
| */ |
| static noinline int do_init_module(struct module *mod) |
| { |
| int ret = 0; |
| struct mod_initfree *freeinit; |
| |
| freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL); |
| if (!freeinit) { |
| ret = -ENOMEM; |
| goto fail; |
| } |
| freeinit->module_init = mod->init_layout.base; |
| |
| do_mod_ctors(mod); |
| /* Start the module */ |
| if (mod->init != NULL) |
| ret = do_one_initcall(mod->init); |
| if (ret < 0) { |
| goto fail_free_freeinit; |
| } |
| if (ret > 0) { |
| pr_warn("%s: '%s'->init suspiciously returned %d, it should " |
| "follow 0/-E convention\n" |
| "%s: loading module anyway...\n", |
| __func__, mod->name, ret, __func__); |
| dump_stack(); |
| } |
| |
| /* Now it's a first class citizen! */ |
| mod->state = MODULE_STATE_LIVE; |
| blocking_notifier_call_chain(&module_notify_list, |
| MODULE_STATE_LIVE, mod); |
| |
| /* Delay uevent until module has finished its init routine */ |
| kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); |
| |
| /* |
| * We need to finish all async code before the module init sequence |
| * is done. This has potential to deadlock if synchronous module |
| * loading is requested from async (which is not allowed!). |
| * |
| * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous |
| * request_module() from async workers") for more details. |
| */ |
| if (!mod->async_probe_requested) |
| async_synchronize_full(); |
| |
| ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base + |
| mod->init_layout.size); |
| mutex_lock(&module_mutex); |
| /* Drop initial reference. */ |
| module_put(mod); |
| trim_init_extable(mod); |
| #ifdef CONFIG_KALLSYMS |
| /* Switch to core kallsyms now init is done: kallsyms may be walking! */ |
| rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms); |
| #endif |
| module_enable_ro(mod, true); |
| trace_android_vh_set_module_permit_after_init(mod); |
| mod_tree_remove_init(mod); |
| module_arch_freeing_init(mod); |
| trace_android_vh_set_memory_rw((unsigned long)mod->init_layout.base, |
| (mod->init_layout.size)>>PAGE_SHIFT); |
| trace_android_vh_set_memory_nx((unsigned long)mod->init_layout.base, |
| (mod->init_layout.size)>>PAGE_SHIFT); |
| mod->init_layout.base = NULL; |
| mod->init_layout.size = 0; |
| mod->init_layout.ro_size = 0; |
| mod->init_layout.ro_after_init_size = 0; |
| mod->init_layout.text_size = 0; |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */ |
| mod->btf_data = NULL; |
| #endif |
| /* |
| * We want to free module_init, but be aware that kallsyms may be |
| * walking this with preempt disabled. In all the failure paths, we |
| * call synchronize_rcu(), but we don't want to slow down the success |
| * path. module_memfree() cannot be called in an interrupt, so do the |
| * work and call synchronize_rcu() in a work queue. |
| * |
| * Note that module_alloc() on most architectures creates W+X page |
| * mappings which won't be cleaned up until do_free_init() runs. Any |
| * code such as mark_rodata_ro() which depends on those mappings to |
| * be cleaned up needs to sync with the queued work - ie |
| * rcu_barrier() |
| */ |
| if (llist_add(&freeinit->node, &init_free_list)) |
| schedule_work(&init_free_wq); |
| |
| mutex_unlock(&module_mutex); |
| wake_up_all(&module_wq); |
| |
| return 0; |
| |
| fail_free_freeinit: |
| kfree(freeinit); |
| fail: |
| /* Try to protect us from buggy refcounters. */ |
| mod->state = MODULE_STATE_GOING; |
| synchronize_rcu(); |
| module_put(mod); |
| blocking_notifier_call_chain(&module_notify_list, |
| MODULE_STATE_GOING, mod); |
| klp_module_going(mod); |
| ftrace_release_mod(mod); |
| free_module(mod); |
| wake_up_all(&module_wq); |
| return ret; |
| } |
| |
| static int may_init_module(void) |
| { |
| if (!capable(CAP_SYS_MODULE) || modules_disabled) |
| return -EPERM; |
| |
| return 0; |
| } |
| |
| /* |
| * We try to place it in the list now to make sure it's unique before |
| * we dedicate too many resources. In particular, temporary percpu |
| * memory exhaustion. |
| */ |
| static int add_unformed_module(struct module *mod) |
| { |
| int err; |
| struct module *old; |
| |
| mod->state = MODULE_STATE_UNFORMED; |
| |
| mutex_lock(&module_mutex); |
| old = find_module_all(mod->name, strlen(mod->name), true); |
| if (old != NULL) { |
| if (old->state == MODULE_STATE_COMING |
| || old->state == MODULE_STATE_UNFORMED) { |
| /* 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; |
| |
| /* The module might have gone in the meantime. */ |
| mutex_lock(&module_mutex); |
| old = find_module_all(mod->name, strlen(mod->name), |
| true); |
| } |
| |
| /* |
| * We are here only when the same module was being loaded. Do |
| * not try to load it again right now. It prevents long delays |
| * caused by serialized module load failures. It might happen |
| * when more devices of the same type trigger load of |
| * a particular module. |
| */ |
| if (old && old->state == MODULE_STATE_LIVE) |
| err = -EEXIST; |
| else |
| err = -EBUSY; |
| 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); |
| trace_android_vh_set_module_permit_before_init(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; |
| |
| err = blocking_notifier_call_chain_robust(&module_notify_list, |
| MODULE_STATE_COMING, MODULE_STATE_GOING, mod); |
| err = notifier_to_errno(err); |
| if (err) |
| klp_module_going(mod); |
| |
| return err; |
| } |
| |
| static int unknown_module_param_cb(char *param, char *val, const char *modname, |
| void *arg) |
| { |
| struct module *mod = arg; |
| int ret; |
| |
| if (strcmp(param, "async_probe") == 0) { |
| mod->async_probe_requested = true; |
| return 0; |
| } |
| |
| /* Check for magic 'dyndbg' arg */ |
| ret = ddebug_dyndbg_module_param_cb(param, val, modname); |
| if (ret != 0) |
| pr_warn("%s: unknown parameter '%s' ignored\n", modname, param); |
| return 0; |
| } |
| |
| static void cfi_init(struct module *mod); |
| |
| /* |
| * Allocate and load the module: note that size of section 0 is always |
| * zero, and we rely on this for optional sections. |
| */ |
| static int load_module(struct load_info *info, const char __user *uargs, |
| int flags) |
| { |
| struct module *mod; |
| long err = 0; |
| char *after_dashes; |
| |
| /* |
| * Do the signature check (if any) first. All that |
| * the signature check needs is info->len, it does |
| * not need any of the section info. That can be |
| * set up later. This will minimize the chances |
| * of a corrupt module causing problems before |
| * we even get to the signature check. |
| * |
| * The check will also adjust info->len by stripping |
| * off the sig length at the end of the module, making |
| * checks against info->len more correct. |
| */ |
| err = module_sig_check(info, flags); |
| if (err) |
| goto free_copy; |
| |
| /* |
| * Do basic sanity checks against the ELF header and |
| * sections. |
| */ |
| err = elf_validity_check(info); |
| if (err) |
| goto free_copy; |
| |
| /* |
| * Everything checks out, so set up the section info |
| * in the info structure. |
| */ |
| err = setup_load_info(info, flags); |
| if (err) |
| goto free_copy; |
| |
| /* |
| * Now that we know we have the correct module name, check |
| * if it's blacklisted. |
| */ |
| if (blacklisted(info->name)) { |
| err = -EPERM; |
| pr_err("Module %s is blacklisted\n", info->name); |
| goto free_copy; |
| } |
| |
| err = rewrite_section_headers(info, flags); |
| if (err) |
| goto free_copy; |
| |
| /* Check module struct version now, before we try to use module. */ |
| if (!check_modstruct_version(info, info->mod)) { |
| err = -ENOEXEC; |
| goto free_copy; |
| } |
| |
| /* Figure out module layout, and allocate all the memory. */ |
| mod = layout_and_allocate(info, flags); |
| if (IS_ERR(mod)) { |
| err = PTR_ERR(mod); |
| goto free_copy; |
| } |
| |
| audit_log_kern_module(mod->name); |
| |
| /* Reserve our place in the list. */ |
| err = add_unformed_module(mod); |
| if (err) |
| goto free_module; |
| |
| #ifdef CONFIG_MODULE_SIG |
| mod->sig_ok = info->sig_ok; |
| if (!mod->sig_ok) { |
| pr_notice_once("%s: module verification failed: signature " |
| "and/or required key missing - tainting " |
| "kernel\n", mod->name); |
| add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK); |
| } |
| #else |
| mod->sig_ok = 0; |
| #endif |
| |
| /* To avoid stressing percpu allocator, do this once we're unique. */ |
| err = percpu_modalloc(mod, info); |
| if (err) |
| goto unlink_mod; |
| |
| /* Now module is in final location, initialize linked lists, etc. */ |
| err = module_unload_init(mod); |
| if (err) |
| goto unlink_mod; |
| |
| init_param_lock(mod); |
| |
| /* |
| * Now we've got everything in the final locations, we can |
| * find optional sections. |
| */ |
| err = find_module_sections(mod, info); |
| if (err) |
| goto free_unload; |
| |
| err = check_module_license_and_versions(mod); |
| if (err) |
| goto free_unload; |
| |
| /* Set up MODINFO_ATTR fields */ |
| setup_modinfo(mod, info); |
| |
| /* Fix up syms, so that st_value is a pointer to location. */ |
| err = simplify_symbols(mod, info); |
| if (err < 0) |
| goto free_modinfo; |
| |
| err = apply_relocations(mod, info); |
| if (err < 0) |
| goto free_modinfo; |
| |
| err = post_relocation(mod, info); |
| if (err < 0) |
| goto free_modinfo; |
| |
| flush_module_icache(mod); |
| |
| /* Setup CFI for the module. */ |
| cfi_init(mod); |
| |
| /* Now copy in args */ |
| mod->args = strndup_user(uargs, ~0UL >> 1); |
| if (IS_ERR(mod->args)) { |
| err = PTR_ERR(mod->args); |
| goto free_arch_cleanup; |
| } |
| |
| init_build_id(mod, info); |
| dynamic_debug_setup(mod, info->debug, info->num_debug); |
| |
| /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ |
| ftrace_module_init(mod); |
| |
| /* Finally it's fully formed, ready to start executing. */ |
| err = complete_formation(mod, info); |
| if (err) |
| goto ddebug_cleanup; |
| |
| err = prepare_coming_module(mod); |
| if (err) |
| goto bug_cleanup; |
| |
| /* 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: |
| mod->state = MODULE_STATE_GOING; |
| /* module_bug_cleanup needs module_mutex protection */ |
| mutex_lock(&module_mutex); |
| module_bug_cleanup(mod); |
| mutex_unlock(&module_mutex); |
| |
| ddebug_cleanup: |
| ftrace_release_mod(mod); |
| dynamic_debug_remove(mod, info->debug); |
| synchronize_rcu(); |
| kfree(mod->args); |
| free_arch_cleanup: |
| cfi_cleanup(mod); |
| module_arch_cleanup(mod); |
| free_modinfo: |
| free_modinfo(mod); |
| free_unload: |
| module_unload_free(mod); |
| unlink_mod: |
| mutex_lock(&module_mutex); |
| /* Unlink carefully: kallsyms could be walking list. */ |
| list_del_rcu(&mod->list); |
| mod_tree_remove(mod); |
| wake_up_all(&module_wq); |
| /* Wait for RCU-sched synchronizing before releasing mod->list. */ |
| synchronize_rcu(); |
| mutex_unlock(&module_mutex); |
| free_module: |
| /* Free lock-classes; relies on the preceding sync_rcu() */ |
| lockdep_free_key_range(mod->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 = { }; |
| void *hdr = NULL; |
| 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, 0, &hdr, INT_MAX, NULL, |
| READING_MODULE); |
| if (err < 0) |
| return err; |
| info.hdr = hdr; |
| info.len = err; |
| |
| 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, |
| const unsigned char **modbuildid, |
| char *namebuf) |
| { |
| const char *ret = NULL; |
| struct module *mod; |
| |
| preempt_disable(); |
| mod = __module_address(addr); |
| if (mod) { |
| if (modname) |
| *modname = mod->name; |
| if (modbuildid) { |
| #if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) |
| *modbuildid = mod->build_id; |
| #else |
| *modbuildid = NULL; |
| #endif |
| } |
| |
| 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 = 0; |
| |
| mutex_lock(&module_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) |
| goto out; |
| } |
| } |
| out: |
| mutex_unlock(&module_mutex); |
| return ret; |
| } |
| #endif /* CONFIG_KALLSYMS */ |
| |
| static void cfi_init(struct module *mod) |
| { |
| #ifdef CONFIG_CFI_CLANG |
| initcall_t *init; |
| exitcall_t *exit; |
| |
| rcu_read_lock_sched(); |
| mod->cfi_check = (cfi_check_fn) |
| find_kallsyms_symbol_value(mod, "__cfi_check"); |
| init = (initcall_t *) |
| find_kallsyms_symbol_value(mod, "__cfi_jt_init_module"); |
| exit = (exitcall_t *) |
| find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module"); |
| rcu_read_unlock_sched(); |
| |
| /* Fix init/exit functions to point to the CFI jump table */ |
| if (init) |
| mod->init = *init; |
| #ifdef CONFIG_MODULE_UNLOAD |
| if (exit) |
| mod->exit = *exit; |
| #endif |
| |
| cfi_module_add(mod, module_addr_min); |
| #endif |
| } |
| |
| static void cfi_cleanup(struct module *mod) |
| { |
| #ifdef CONFIG_CFI_CLANG |
| cfi_module_remove(mod, module_addr_min); |
| #endif |
| } |
| |
| /* 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(file->f_cred) ? NULL : (void *)8ul; |
| } |
| |
| return err; |
| } |
| |
| static const struct proc_ops modules_proc_ops = { |
| .proc_flags = PROC_ENTRY_PERMANENT, |
| .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; |
| } |
| |
| /** |
| * 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; |
| } |
| |
| /* 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_ANDROID_DEBUG_SYMBOLS |
| void android_debug_for_each_module(int (*fn)(const char *mod_name, void *mod_addr, void *data), |
| void *data) |
| { |
| struct module *module; |
| preempt_disable(); |
| list_for_each_entry_rcu(module, &modules, list) { |
| if (fn(module->name, module->core_layout.base, data)) |
| goto out; |
| } |
| out: |
| preempt_enable(); |
| } |
| EXPORT_SYMBOL_NS_GPL(android_debug_for_each_module, MINIDUMP); |
| #endif |
| |
| #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 |