| /* |
| Copyright (C) 2002 Richard Henderson |
| Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| #include <linux/export.h> |
| #include <linux/extable.h> |
| #include <linux/moduleloader.h> |
| #include <linux/trace_events.h> |
| #include <linux/init.h> |
| #include <linux/kallsyms.h> |
| #include <linux/file.h> |
| #include <linux/fs.h> |
| #include <linux/sysfs.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/vmalloc.h> |
| #include <linux/elf.h> |
| #include <linux/proc_fs.h> |
| #include <linux/security.h> |
| #include <linux/seq_file.h> |
| #include <linux/syscalls.h> |
| #include <linux/fcntl.h> |
| #include <linux/rcupdate.h> |
| #include <linux/capability.h> |
| #include <linux/cpu.h> |
| #include <linux/moduleparam.h> |
| #include <linux/errno.h> |
| #include <linux/err.h> |
| #include <linux/vermagic.h> |
| #include <linux/notifier.h> |
| #include <linux/sched.h> |
| #include <linux/device.h> |
| #include <linux/string.h> |
| #include <linux/mutex.h> |
| #include <linux/rculist.h> |
| #include <linux/uaccess.h> |
| #include <asm/cacheflush.h> |
| #include <linux/set_memory.h> |
| #include <asm/mmu_context.h> |
| #include <linux/license.h> |
| #include <asm/sections.h> |
| #include <linux/tracepoint.h> |
| #include <linux/ftrace.h> |
| #include <linux/livepatch.h> |
| #include <linux/async.h> |
| #include <linux/percpu.h> |
| #include <linux/kmemleak.h> |
| #include <linux/jump_label.h> |
| #include <linux/pfn.h> |
| #include <linux/bsearch.h> |
| #include <linux/dynamic_debug.h> |
| #include <linux/audit.h> |
| #include <uapi/linux/module.h> |
| #include "module-internal.h" |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/module.h> |
| |
| #ifndef ARCH_SHF_SMALL |
| #define ARCH_SHF_SMALL 0 |
| #endif |
| |
| /* |
| * Modules' sections will be aligned on page boundaries |
| * to ensure complete separation of code and data |
| */ |
| # define debug_align(X) ALIGN(X, PAGE_SIZE) |
| |
| /* If this is set, the section belongs in the init part of the module */ |
| #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) |
| |
| /* |
| * Mutex protects: |
| * 1) List of modules (also safely readable with preempt_disable), |
| * 2) module_use links, |
| * 3) module_addr_min/module_addr_max. |
| * (delete and add uses RCU list operations). */ |
| DEFINE_MUTEX(module_mutex); |
| EXPORT_SYMBOL_GPL(module_mutex); |
| static LIST_HEAD(modules); |
| |
| #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) { |
| if (within_module(addr, mod)) |
| return mod; |
| } |
| |
| return NULL; |
| } |
| |
| #endif /* MODULES_TREE_LOOKUP */ |
| |
| /* |
| * Bounds of module text, for speeding up __module_address. |
| * Protected by module_mutex. |
| */ |
| static void __mod_update_bounds(void *base, unsigned int size) |
| { |
| unsigned long min = (unsigned long)base; |
| unsigned long max = min + size; |
| |
| if (min < module_addr_min) |
| module_addr_min = min; |
| if (max > module_addr_max) |
| module_addr_max = max; |
| } |
| |
| static void mod_update_bounds(struct module *mod) |
| { |
| __mod_update_bounds(mod->core_layout.base, mod->core_layout.size); |
| if (mod->init_layout.size) |
| __mod_update_bounds(mod->init_layout.base, mod->init_layout.size); |
| } |
| |
| #ifdef CONFIG_KGDB_KDB |
| struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ |
| #endif /* CONFIG_KGDB_KDB */ |
| |
| static void module_assert_mutex(void) |
| { |
| lockdep_assert_held(&module_mutex); |
| } |
| |
| static void module_assert_mutex_or_preempt(void) |
| { |
| #ifdef CONFIG_LOCKDEP |
| if (unlikely(!debug_locks)) |
| return; |
| |
| WARN_ON_ONCE(!rcu_read_lock_sched_held() && |
| !lockdep_is_held(&module_mutex)); |
| #endif |
| } |
| |
| static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); |
| module_param(sig_enforce, bool_enable_only, 0644); |
| |
| /* |
| * Export sig_enforce kernel cmdline parameter to allow other subsystems rely |
| * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. |
| */ |
| bool is_module_sig_enforced(void) |
| { |
| return sig_enforce; |
| } |
| EXPORT_SYMBOL(is_module_sig_enforced); |
| |
| /* Block module loading/unloading? */ |
| int modules_disabled = 0; |
| core_param(nomodule, modules_disabled, bint, 0); |
| |
| /* Waiting for a module to finish initializing? */ |
| static DECLARE_WAIT_QUEUE_HEAD(module_wq); |
| |
| static BLOCKING_NOTIFIER_HEAD(module_notify_list); |
| |
| int register_module_notifier(struct notifier_block *nb) |
| { |
| return blocking_notifier_chain_register(&module_notify_list, nb); |
| } |
| EXPORT_SYMBOL(register_module_notifier); |
| |
| int unregister_module_notifier(struct notifier_block *nb) |
| { |
| return blocking_notifier_chain_unregister(&module_notify_list, nb); |
| } |
| EXPORT_SYMBOL(unregister_module_notifier); |
| |
| /* |
| * We require a truly strong try_module_get(): 0 means success. |
| * Otherwise an error is returned due to ongoing or failed |
| * initialization etc. |
| */ |
| static inline int strong_try_module_get(struct module *mod) |
| { |
| BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); |
| if (mod && mod->state == MODULE_STATE_COMING) |
| return -EBUSY; |
| if (try_module_get(mod)) |
| return 0; |
| else |
| return -ENOENT; |
| } |
| |
| static inline void add_taint_module(struct module *mod, unsigned flag, |
| enum lockdep_ok lockdep_ok) |
| { |
| add_taint(flag, lockdep_ok); |
| set_bit(flag, &mod->taints); |
| } |
| |
| /* |
| * A thread that wants to hold a reference to a module only while it |
| * is running can call this to safely exit. nfsd and lockd use this. |
| */ |
| void __noreturn __module_put_and_exit(struct module *mod, long code) |
| { |
| module_put(mod); |
| do_exit(code); |
| } |
| EXPORT_SYMBOL(__module_put_and_exit); |
| |
| /* Find a module section: 0 means not found. */ |
| static unsigned int find_sec(const struct load_info *info, const char *name) |
| { |
| unsigned int i; |
| |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| Elf_Shdr *shdr = &info->sechdrs[i]; |
| /* Alloc bit cleared means "ignore it." */ |
| if ((shdr->sh_flags & SHF_ALLOC) |
| && strcmp(info->secstrings + shdr->sh_name, name) == 0) |
| return i; |
| } |
| return 0; |
| } |
| |
| /* Find a module section, or NULL. */ |
| static void *section_addr(const struct load_info *info, const char *name) |
| { |
| /* Section 0 has sh_addr 0. */ |
| return (void *)info->sechdrs[find_sec(info, name)].sh_addr; |
| } |
| |
| /* Find a module section, or NULL. Fill in number of "objects" in section. */ |
| static void *section_objs(const struct load_info *info, |
| const char *name, |
| size_t object_size, |
| unsigned int *num) |
| { |
| unsigned int sec = find_sec(info, name); |
| |
| /* Section 0 has sh_addr 0 and sh_size 0. */ |
| *num = info->sechdrs[sec].sh_size / object_size; |
| return (void *)info->sechdrs[sec].sh_addr; |
| } |
| |
| /* Provided by the linker */ |
| extern const struct kernel_symbol __start___ksymtab[]; |
| extern const struct kernel_symbol __stop___ksymtab[]; |
| extern const struct kernel_symbol __start___ksymtab_gpl[]; |
| extern const struct kernel_symbol __stop___ksymtab_gpl[]; |
| extern const struct kernel_symbol __start___ksymtab_gpl_future[]; |
| extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; |
| extern const s32 __start___kcrctab[]; |
| extern const s32 __start___kcrctab_gpl[]; |
| extern const s32 __start___kcrctab_gpl_future[]; |
| #ifdef CONFIG_UNUSED_SYMBOLS |
| extern const struct kernel_symbol __start___ksymtab_unused[]; |
| extern const struct kernel_symbol __stop___ksymtab_unused[]; |
| extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; |
| extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; |
| extern const s32 __start___kcrctab_unused[]; |
| extern const s32 __start___kcrctab_unused_gpl[]; |
| #endif |
| |
| #ifndef CONFIG_MODVERSIONS |
| #define symversion(base, idx) NULL |
| #else |
| #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) |
| #endif |
| |
| static bool each_symbol_in_section(const struct symsearch *arr, |
| unsigned int arrsize, |
| struct module *owner, |
| bool (*fn)(const struct symsearch *syms, |
| struct module *owner, |
| void *data), |
| void *data) |
| { |
| unsigned int j; |
| |
| for (j = 0; j < arrsize; j++) { |
| if (fn(&arr[j], owner, data)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* Returns true as soon as fn returns true, otherwise false. */ |
| bool each_symbol_section(bool (*fn)(const struct symsearch *arr, |
| struct module *owner, |
| void *data), |
| void *data) |
| { |
| struct module *mod; |
| static const struct symsearch arr[] = { |
| { __start___ksymtab, __stop___ksymtab, __start___kcrctab, |
| NOT_GPL_ONLY, false }, |
| { __start___ksymtab_gpl, __stop___ksymtab_gpl, |
| __start___kcrctab_gpl, |
| GPL_ONLY, false }, |
| { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, |
| __start___kcrctab_gpl_future, |
| WILL_BE_GPL_ONLY, false }, |
| #ifdef CONFIG_UNUSED_SYMBOLS |
| { __start___ksymtab_unused, __stop___ksymtab_unused, |
| __start___kcrctab_unused, |
| NOT_GPL_ONLY, true }, |
| { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, |
| __start___kcrctab_unused_gpl, |
| GPL_ONLY, true }, |
| #endif |
| }; |
| |
| module_assert_mutex_or_preempt(); |
| |
| if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) |
| return true; |
| |
| list_for_each_entry_rcu(mod, &modules, list) { |
| struct symsearch arr[] = { |
| { mod->syms, mod->syms + mod->num_syms, mod->crcs, |
| NOT_GPL_ONLY, false }, |
| { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, |
| mod->gpl_crcs, |
| GPL_ONLY, false }, |
| { mod->gpl_future_syms, |
| mod->gpl_future_syms + mod->num_gpl_future_syms, |
| mod->gpl_future_crcs, |
| WILL_BE_GPL_ONLY, false }, |
| #ifdef CONFIG_UNUSED_SYMBOLS |
| { mod->unused_syms, |
| mod->unused_syms + mod->num_unused_syms, |
| mod->unused_crcs, |
| NOT_GPL_ONLY, true }, |
| { mod->unused_gpl_syms, |
| mod->unused_gpl_syms + mod->num_unused_gpl_syms, |
| mod->unused_gpl_crcs, |
| GPL_ONLY, true }, |
| #endif |
| }; |
| |
| if (mod->state == MODULE_STATE_UNFORMED) |
| continue; |
| |
| if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) |
| return true; |
| } |
| return false; |
| } |
| EXPORT_SYMBOL_GPL(each_symbol_section); |
| |
| struct find_symbol_arg { |
| /* Input */ |
| const char *name; |
| bool gplok; |
| bool warn; |
| |
| /* Output */ |
| struct module *owner; |
| const s32 *crc; |
| const struct kernel_symbol *sym; |
| }; |
| |
| static bool check_symbol(const struct symsearch *syms, |
| struct module *owner, |
| unsigned int symnum, void *data) |
| { |
| struct find_symbol_arg *fsa = data; |
| |
| if (!fsa->gplok) { |
| if (syms->licence == GPL_ONLY) |
| return false; |
| if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { |
| pr_warn("Symbol %s is being used by a non-GPL module, " |
| "which will not be allowed in the future\n", |
| fsa->name); |
| } |
| } |
| |
| #ifdef CONFIG_UNUSED_SYMBOLS |
| if (syms->unused && fsa->warn) { |
| pr_warn("Symbol %s is marked as UNUSED, however this module is " |
| "using it.\n", fsa->name); |
| pr_warn("This symbol will go away in the future.\n"); |
| pr_warn("Please evaluate if this is the right api to use and " |
| "if it really is, submit a report to the linux kernel " |
| "mailing list together with submitting your code for " |
| "inclusion.\n"); |
| } |
| #endif |
| |
| fsa->owner = owner; |
| fsa->crc = symversion(syms->crcs, symnum); |
| fsa->sym = &syms->start[symnum]; |
| return true; |
| } |
| |
| static unsigned long kernel_symbol_value(const struct kernel_symbol *sym) |
| { |
| #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
| return (unsigned long)offset_to_ptr(&sym->value_offset); |
| #else |
| return sym->value; |
| #endif |
| } |
| |
| static const char *kernel_symbol_name(const struct kernel_symbol *sym) |
| { |
| #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
| return offset_to_ptr(&sym->name_offset); |
| #else |
| return sym->name; |
| #endif |
| } |
| |
| static int cmp_name(const void *va, const void *vb) |
| { |
| const char *a; |
| const struct kernel_symbol *b; |
| a = va; b = vb; |
| return strcmp(a, kernel_symbol_name(b)); |
| } |
| |
| static bool find_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_symbol(syms, owner, sym - syms->start, data)) |
| return true; |
| |
| return false; |
| } |
| |
| /* Find a symbol and return it, along with, (optional) crc and |
| * (optional) module which owns it. Needs preempt disabled or module_mutex. */ |
| const struct kernel_symbol *find_symbol(const char *name, |
| struct module **owner, |
| const s32 **crc, |
| bool gplok, |
| bool warn) |
| { |
| struct find_symbol_arg fsa; |
| |
| fsa.name = name; |
| fsa.gplok = gplok; |
| fsa.warn = warn; |
| |
| if (each_symbol_section(find_symbol_in_section, &fsa)) { |
| if (owner) |
| *owner = fsa.owner; |
| if (crc) |
| *crc = fsa.crc; |
| return fsa.sym; |
| } |
| |
| pr_debug("Failed to find symbol %s\n", name); |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(find_symbol); |
| |
| /* |
| * Search for module by name: must hold module_mutex (or preempt disabled |
| * for read-only access). |
| */ |
| static struct module *find_module_all(const char *name, size_t len, |
| bool even_unformed) |
| { |
| struct module *mod; |
| |
| module_assert_mutex_or_preempt(); |
| |
| list_for_each_entry_rcu(mod, &modules, list) { |
| if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) |
| continue; |
| if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) |
| return mod; |
| } |
| return NULL; |
| } |
| |
| struct module *find_module(const char *name) |
| { |
| module_assert_mutex(); |
| return find_module_all(name, strlen(name), false); |
| } |
| EXPORT_SYMBOL_GPL(find_module); |
| |
| #ifdef CONFIG_SMP |
| |
| static inline void __percpu *mod_percpu(struct module *mod) |
| { |
| return mod->percpu; |
| } |
| |
| static int percpu_modalloc(struct module *mod, struct load_info *info) |
| { |
| Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; |
| unsigned long align = pcpusec->sh_addralign; |
| |
| if (!pcpusec->sh_size) |
| return 0; |
| |
| if (align > PAGE_SIZE) { |
| pr_warn("%s: per-cpu alignment %li > %li\n", |
| mod->name, align, PAGE_SIZE); |
| align = PAGE_SIZE; |
| } |
| |
| mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); |
| if (!mod->percpu) { |
| pr_warn("%s: Could not allocate %lu bytes percpu data\n", |
| mod->name, (unsigned long)pcpusec->sh_size); |
| return -ENOMEM; |
| } |
| mod->percpu_size = pcpusec->sh_size; |
| return 0; |
| } |
| |
| static void percpu_modfree(struct module *mod) |
| { |
| free_percpu(mod->percpu); |
| } |
| |
| static unsigned int find_pcpusec(struct load_info *info) |
| { |
| return find_sec(info, ".data..percpu"); |
| } |
| |
| static void percpu_modcopy(struct module *mod, |
| const void *from, unsigned long size) |
| { |
| int cpu; |
| |
| for_each_possible_cpu(cpu) |
| memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); |
| } |
| |
| bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) |
| { |
| struct module *mod; |
| unsigned int cpu; |
| |
| preempt_disable(); |
| |
| list_for_each_entry_rcu(mod, &modules, list) { |
| if (mod->state == MODULE_STATE_UNFORMED) |
| continue; |
| if (!mod->percpu_size) |
| continue; |
| for_each_possible_cpu(cpu) { |
| void *start = per_cpu_ptr(mod->percpu, cpu); |
| void *va = (void *)addr; |
| |
| if (va >= start && va < start + mod->percpu_size) { |
| if (can_addr) { |
| *can_addr = (unsigned long) (va - start); |
| *can_addr += (unsigned long) |
| per_cpu_ptr(mod->percpu, |
| get_boot_cpu_id()); |
| } |
| preempt_enable(); |
| return true; |
| } |
| } |
| } |
| |
| preempt_enable(); |
| return false; |
| } |
| |
| /** |
| * is_module_percpu_address - test whether address is from module static percpu |
| * @addr: address to test |
| * |
| * Test whether @addr belongs to module static percpu area. |
| * |
| * RETURNS: |
| * %true if @addr is from module static percpu area |
| */ |
| bool is_module_percpu_address(unsigned long addr) |
| { |
| return __is_module_percpu_address(addr, NULL); |
| } |
| |
| #else /* ... !CONFIG_SMP */ |
| |
| static inline void __percpu *mod_percpu(struct module *mod) |
| { |
| return NULL; |
| } |
| static int percpu_modalloc(struct module *mod, struct load_info *info) |
| { |
| /* UP modules shouldn't have this section: ENOMEM isn't quite right */ |
| if (info->sechdrs[info->index.pcpu].sh_size != 0) |
| return -ENOMEM; |
| return 0; |
| } |
| static inline void percpu_modfree(struct module *mod) |
| { |
| } |
| static unsigned int find_pcpusec(struct load_info *info) |
| { |
| return 0; |
| } |
| static inline void percpu_modcopy(struct module *mod, |
| const void *from, unsigned long size) |
| { |
| /* pcpusec should be 0, and size of that section should be 0. */ |
| BUG_ON(size != 0); |
| } |
| bool is_module_percpu_address(unsigned long addr) |
| { |
| return false; |
| } |
| |
| bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) |
| { |
| return false; |
| } |
| |
| #endif /* CONFIG_SMP */ |
| |
| #define MODINFO_ATTR(field) \ |
| static void setup_modinfo_##field(struct module *mod, const char *s) \ |
| { \ |
| mod->field = kstrdup(s, GFP_KERNEL); \ |
| } \ |
| static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ |
| struct module_kobject *mk, char *buffer) \ |
| { \ |
| return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ |
| } \ |
| static int modinfo_##field##_exists(struct module *mod) \ |
| { \ |
| return mod->field != NULL; \ |
| } \ |
| static void free_modinfo_##field(struct module *mod) \ |
| { \ |
| kfree(mod->field); \ |
| mod->field = NULL; \ |
| } \ |
| static struct module_attribute modinfo_##field = { \ |
| .attr = { .name = __stringify(field), .mode = 0444 }, \ |
| .show = show_modinfo_##field, \ |
| .setup = setup_modinfo_##field, \ |
| .test = modinfo_##field##_exists, \ |
| .free = free_modinfo_##field, \ |
| }; |
| |
| MODINFO_ATTR(version); |
| MODINFO_ATTR(srcversion); |
| |
| static char last_unloaded_module[MODULE_NAME_LEN+1]; |
| |
| #ifdef CONFIG_MODULE_UNLOAD |
| |
| EXPORT_TRACEPOINT_SYMBOL(module_get); |
| |
| /* MODULE_REF_BASE is the base reference count by kmodule loader. */ |
| #define MODULE_REF_BASE 1 |
| |
| /* Init the unload section of the module. */ |
| static int module_unload_init(struct module *mod) |
| { |
| /* |
| * Initialize reference counter to MODULE_REF_BASE. |
| * refcnt == 0 means module is going. |
| */ |
| atomic_set(&mod->refcnt, MODULE_REF_BASE); |
| |
| INIT_LIST_HEAD(&mod->source_list); |
| INIT_LIST_HEAD(&mod->target_list); |
| |
| /* Hold reference count during initialization. */ |
| atomic_inc(&mod->refcnt); |
| |
| return 0; |
| } |
| |
| /* Does a already use b? */ |
| static int already_uses(struct module *a, struct module *b) |
| { |
| struct module_use *use; |
| |
| list_for_each_entry(use, &b->source_list, source_list) { |
| if (use->source == a) { |
| pr_debug("%s uses %s!\n", a->name, b->name); |
| return 1; |
| } |
| } |
| pr_debug("%s does not use %s!\n", a->name, b->name); |
| return 0; |
| } |
| |
| /* |
| * Module a uses b |
| * - we add 'a' as a "source", 'b' as a "target" of module use |
| * - the module_use is added to the list of 'b' sources (so |
| * 'b' can walk the list to see who sourced them), and of 'a' |
| * targets (so 'a' can see what modules it targets). |
| */ |
| static int add_module_usage(struct module *a, struct module *b) |
| { |
| struct module_use *use; |
| |
| pr_debug("Allocating new usage for %s.\n", a->name); |
| use = kmalloc(sizeof(*use), GFP_ATOMIC); |
| if (!use) |
| return -ENOMEM; |
| |
| use->source = a; |
| use->target = b; |
| list_add(&use->source_list, &b->source_list); |
| list_add(&use->target_list, &a->target_list); |
| return 0; |
| } |
| |
| /* Module a uses b: caller needs module_mutex() */ |
| int ref_module(struct module *a, struct module *b) |
| { |
| int err; |
| |
| if (b == NULL || already_uses(a, b)) |
| return 0; |
| |
| /* If module isn't available, we fail. */ |
| err = strong_try_module_get(b); |
| if (err) |
| return err; |
| |
| err = add_module_usage(a, b); |
| if (err) { |
| module_put(b); |
| return err; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(ref_module); |
| |
| /* Clear the unload stuff of the module. */ |
| static void module_unload_free(struct module *mod) |
| { |
| struct module_use *use, *tmp; |
| |
| mutex_lock(&module_mutex); |
| list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { |
| struct module *i = use->target; |
| pr_debug("%s unusing %s\n", mod->name, i->name); |
| module_put(i); |
| list_del(&use->source_list); |
| list_del(&use->target_list); |
| kfree(use); |
| } |
| mutex_unlock(&module_mutex); |
| } |
| |
| #ifdef CONFIG_MODULE_FORCE_UNLOAD |
| static inline int try_force_unload(unsigned int flags) |
| { |
| int ret = (flags & O_TRUNC); |
| if (ret) |
| add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); |
| return ret; |
| } |
| #else |
| static inline int try_force_unload(unsigned int flags) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_MODULE_FORCE_UNLOAD */ |
| |
| /* Try to release refcount of module, 0 means success. */ |
| static int try_release_module_ref(struct module *mod) |
| { |
| int ret; |
| |
| /* Try to decrement refcnt which we set at loading */ |
| ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); |
| BUG_ON(ret < 0); |
| if (ret) |
| /* Someone can put this right now, recover with checking */ |
| ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); |
| |
| return ret; |
| } |
| |
| static int try_stop_module(struct module *mod, int flags, int *forced) |
| { |
| /* If it's not unused, quit unless we're forcing. */ |
| if (try_release_module_ref(mod) != 0) { |
| *forced = try_force_unload(flags); |
| if (!(*forced)) |
| return -EWOULDBLOCK; |
| } |
| |
| /* Mark it as dying. */ |
| mod->state = MODULE_STATE_GOING; |
| |
| return 0; |
| } |
| |
| /** |
| * module_refcount - return the refcount or -1 if unloading |
| * |
| * @mod: the module we're checking |
| * |
| * Returns: |
| * -1 if the module is in the process of unloading |
| * otherwise the number of references in the kernel to the module |
| */ |
| int module_refcount(struct module *mod) |
| { |
| return atomic_read(&mod->refcnt) - MODULE_REF_BASE; |
| } |
| EXPORT_SYMBOL(module_refcount); |
| |
| /* This exists whether we can unload or not */ |
| static void free_module(struct module *mod); |
| |
| SYSCALL_DEFINE2(delete_module, const char __user *, name_user, |
| unsigned int, flags) |
| { |
| struct module *mod; |
| char name[MODULE_NAME_LEN]; |
| int ret, forced = 0; |
| |
| if (!capable(CAP_SYS_MODULE) || modules_disabled) |
| return -EPERM; |
| |
| if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) |
| return -EFAULT; |
| name[MODULE_NAME_LEN-1] = '\0'; |
| |
| audit_log_kern_module(name); |
| |
| if (mutex_lock_interruptible(&module_mutex) != 0) |
| return -EINTR; |
| |
| mod = find_module(name); |
| if (!mod) { |
| ret = -ENOENT; |
| goto out; |
| } |
| |
| if (!list_empty(&mod->source_list)) { |
| /* Other modules depend on us: get rid of them first. */ |
| ret = -EWOULDBLOCK; |
| goto out; |
| } |
| |
| /* Doing init or already dying? */ |
| if (mod->state != MODULE_STATE_LIVE) { |
| /* FIXME: if (force), slam module count damn the torpedoes */ |
| pr_debug("%s already dying\n", mod->name); |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| /* If it has an init func, it must have an exit func to unload */ |
| if (mod->init && !mod->exit) { |
| forced = try_force_unload(flags); |
| if (!forced) { |
| /* This module can't be removed */ |
| ret = -EBUSY; |
| goto out; |
| } |
| } |
| |
| /* Stop the machine so refcounts can't move and disable module. */ |
| ret = try_stop_module(mod, flags, &forced); |
| if (ret != 0) |
| goto out; |
| |
| mutex_unlock(&module_mutex); |
| /* Final destruction now no one is using it. */ |
| if (mod->exit != NULL) |
| mod->exit(); |
| blocking_notifier_call_chain(&module_notify_list, |
| MODULE_STATE_GOING, mod); |
| klp_module_going(mod); |
| ftrace_release_mod(mod); |
| |
| async_synchronize_full(); |
| |
| /* Store the name of the last unloaded module for diagnostic purposes */ |
| strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); |
| |
| free_module(mod); |
| /* someone could wait for the module in add_unformed_module() */ |
| wake_up_all(&module_wq); |
| return 0; |
| out: |
| mutex_unlock(&module_mutex); |
| return ret; |
| } |
| |
| static inline void print_unload_info(struct seq_file *m, struct module *mod) |
| { |
| struct module_use *use; |
| int printed_something = 0; |
| |
| seq_printf(m, " %i ", module_refcount(mod)); |
| |
| /* |
| * Always include a trailing , so userspace can differentiate |
| * between this and the old multi-field proc format. |
| */ |
| list_for_each_entry(use, &mod->source_list, source_list) { |
| printed_something = 1; |
| seq_printf(m, "%s,", use->source->name); |
| } |
| |
| if (mod->init != NULL && mod->exit == NULL) { |
| printed_something = 1; |
| seq_puts(m, "[permanent],"); |
| } |
| |
| if (!printed_something) |
| seq_puts(m, "-"); |
| } |
| |
| void __symbol_put(const char *symbol) |
| { |
| struct module *owner; |
| |
| preempt_disable(); |
| if (!find_symbol(symbol, &owner, NULL, true, false)) |
| BUG(); |
| module_put(owner); |
| preempt_enable(); |
| } |
| EXPORT_SYMBOL(__symbol_put); |
| |
| /* Note this assumes addr is a function, which it currently always is. */ |
| void symbol_put_addr(void *addr) |
| { |
| struct module *modaddr; |
| unsigned long a = (unsigned long)dereference_function_descriptor(addr); |
| |
| if (core_kernel_text(a)) |
| return; |
| |
| /* |
| * Even though we hold a reference on the module; we still need to |
| * disable preemption in order to safely traverse the data structure. |
| */ |
| preempt_disable(); |
| modaddr = __module_text_address(a); |
| BUG_ON(!modaddr); |
| module_put(modaddr); |
| preempt_enable(); |
| } |
| EXPORT_SYMBOL_GPL(symbol_put_addr); |
| |
| static ssize_t show_refcnt(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| return sprintf(buffer, "%i\n", module_refcount(mk->mod)); |
| } |
| |
| static struct module_attribute modinfo_refcnt = |
| __ATTR(refcnt, 0444, show_refcnt, NULL); |
| |
| void __module_get(struct module *module) |
| { |
| if (module) { |
| preempt_disable(); |
| atomic_inc(&module->refcnt); |
| trace_module_get(module, _RET_IP_); |
| preempt_enable(); |
| } |
| } |
| EXPORT_SYMBOL(__module_get); |
| |
| bool try_module_get(struct module *module) |
| { |
| bool ret = true; |
| |
| if (module) { |
| preempt_disable(); |
| /* Note: here, we can fail to get a reference */ |
| if (likely(module_is_live(module) && |
| atomic_inc_not_zero(&module->refcnt) != 0)) |
| trace_module_get(module, _RET_IP_); |
| else |
| ret = false; |
| |
| preempt_enable(); |
| } |
| return ret; |
| } |
| EXPORT_SYMBOL(try_module_get); |
| |
| void module_put(struct module *module) |
| { |
| int ret; |
| |
| if (module) { |
| preempt_disable(); |
| ret = atomic_dec_if_positive(&module->refcnt); |
| WARN_ON(ret < 0); /* Failed to put refcount */ |
| trace_module_put(module, _RET_IP_); |
| preempt_enable(); |
| } |
| } |
| EXPORT_SYMBOL(module_put); |
| |
| #else /* !CONFIG_MODULE_UNLOAD */ |
| static inline void print_unload_info(struct seq_file *m, struct module *mod) |
| { |
| /* We don't know the usage count, or what modules are using. */ |
| seq_puts(m, " - -"); |
| } |
| |
| static inline void module_unload_free(struct module *mod) |
| { |
| } |
| |
| int ref_module(struct module *a, struct module *b) |
| { |
| return strong_try_module_get(b); |
| } |
| EXPORT_SYMBOL_GPL(ref_module); |
| |
| static inline int module_unload_init(struct module *mod) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_MODULE_UNLOAD */ |
| |
| static size_t module_flags_taint(struct module *mod, char *buf) |
| { |
| size_t l = 0; |
| int i; |
| |
| for (i = 0; i < TAINT_FLAGS_COUNT; i++) { |
| if (taint_flags[i].module && test_bit(i, &mod->taints)) |
| buf[l++] = taint_flags[i].c_true; |
| } |
| |
| return l; |
| } |
| |
| static ssize_t show_initstate(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| const char *state = "unknown"; |
| |
| switch (mk->mod->state) { |
| case MODULE_STATE_LIVE: |
| state = "live"; |
| break; |
| case MODULE_STATE_COMING: |
| state = "coming"; |
| break; |
| case MODULE_STATE_GOING: |
| state = "going"; |
| break; |
| default: |
| BUG(); |
| } |
| return sprintf(buffer, "%s\n", state); |
| } |
| |
| static struct module_attribute modinfo_initstate = |
| __ATTR(initstate, 0444, show_initstate, NULL); |
| |
| static ssize_t store_uevent(struct module_attribute *mattr, |
| struct module_kobject *mk, |
| const char *buffer, size_t count) |
| { |
| int rc; |
| |
| rc = kobject_synth_uevent(&mk->kobj, buffer, count); |
| return rc ? rc : count; |
| } |
| |
| struct module_attribute module_uevent = |
| __ATTR(uevent, 0200, NULL, store_uevent); |
| |
| static ssize_t show_coresize(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| return sprintf(buffer, "%u\n", mk->mod->core_layout.size); |
| } |
| |
| static struct module_attribute modinfo_coresize = |
| __ATTR(coresize, 0444, show_coresize, NULL); |
| |
| static ssize_t show_initsize(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| return sprintf(buffer, "%u\n", mk->mod->init_layout.size); |
| } |
| |
| static struct module_attribute modinfo_initsize = |
| __ATTR(initsize, 0444, show_initsize, NULL); |
| |
| static ssize_t show_taint(struct module_attribute *mattr, |
| struct module_kobject *mk, char *buffer) |
| { |
| size_t l; |
| |
| l = module_flags_taint(mk->mod, buffer); |
| buffer[l++] = '\n'; |
| return l; |
| } |
| |
| static struct module_attribute modinfo_taint = |
| __ATTR(taint, 0444, show_taint, NULL); |
| |
| static struct module_attribute *modinfo_attrs[] = { |
| &module_uevent, |
| &modinfo_version, |
| &modinfo_srcversion, |
| &modinfo_initstate, |
| &modinfo_coresize, |
| &modinfo_initsize, |
| &modinfo_taint, |
| #ifdef CONFIG_MODULE_UNLOAD |
| &modinfo_refcnt, |
| #endif |
| NULL, |
| }; |
| |
| static const char vermagic[] = VERMAGIC_STRING; |
| |
| static int try_to_force_load(struct module *mod, const char *reason) |
| { |
| #ifdef CONFIG_MODULE_FORCE_LOAD |
| if (!test_taint(TAINT_FORCED_MODULE)) |
| pr_warn("%s: %s: kernel tainted.\n", mod->name, reason); |
| add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); |
| return 0; |
| #else |
| return -ENOEXEC; |
| #endif |
| } |
| |
| #ifdef CONFIG_MODVERSIONS |
| |
| static u32 resolve_rel_crc(const s32 *crc) |
| { |
| return *(u32 *)((void *)crc + *crc); |
| } |
| |
| static int check_version(const struct load_info *info, |
| const char *symname, |
| struct module *mod, |
| const s32 *crc) |
| { |
| Elf_Shdr *sechdrs = info->sechdrs; |
| unsigned int versindex = info->index.vers; |
| unsigned int i, num_versions; |
| struct modversion_info *versions; |
| |
| /* Exporting module didn't supply crcs? OK, we're already tainted. */ |
| if (!crc) |
| return 1; |
| |
| /* No versions at all? modprobe --force does this. */ |
| if (versindex == 0) |
| return try_to_force_load(mod, symname) == 0; |
| |
| versions = (void *) sechdrs[versindex].sh_addr; |
| num_versions = sechdrs[versindex].sh_size |
| / sizeof(struct modversion_info); |
| |
| for (i = 0; i < num_versions; i++) { |
| u32 crcval; |
| |
| if (strcmp(versions[i].name, symname) != 0) |
| continue; |
| |
| if (IS_ENABLED(CONFIG_MODULE_REL_CRCS)) |
| crcval = resolve_rel_crc(crc); |
| else |
| crcval = *crc; |
| if (versions[i].crc == crcval) |
| return 1; |
| pr_debug("Found checksum %X vs module %lX\n", |
| crcval, versions[i].crc); |
| goto bad_version; |
| } |
| |
| /* Broken toolchain. Warn once, then let it go.. */ |
| pr_warn_once("%s: no symbol version for %s\n", info->name, symname); |
| return 1; |
| |
| bad_version: |
| pr_warn("%s: disagrees about version of symbol %s\n", |
| info->name, symname); |
| return 0; |
| } |
| |
| static inline int check_modstruct_version(const struct load_info *info, |
| struct module *mod) |
| { |
| const s32 *crc; |
| |
| /* |
| * Since this should be found in kernel (which can't be removed), no |
| * locking is necessary -- use preempt_disable() to placate lockdep. |
| */ |
| preempt_disable(); |
| if (!find_symbol("module_layout", NULL, &crc, true, false)) { |
| preempt_enable(); |
| BUG(); |
| } |
| preempt_enable(); |
| return check_version(info, "module_layout", mod, crc); |
| } |
| |
| /* First part is kernel version, which we ignore if module has crcs. */ |
| static inline int same_magic(const char *amagic, const char *bmagic, |
| bool has_crcs) |
| { |
| if (has_crcs) { |
| amagic += strcspn(amagic, " "); |
| bmagic += strcspn(bmagic, " "); |
| } |
| return strcmp(amagic, bmagic) == 0; |
| } |
| #else |
| static inline int check_version(const struct load_info *info, |
| const char *symname, |
| struct module *mod, |
| const s32 *crc) |
| { |
| return 1; |
| } |
| |
| static inline int check_modstruct_version(const struct load_info *info, |
| struct module *mod) |
| { |
| return 1; |
| } |
| |
| static inline int same_magic(const char *amagic, const char *bmagic, |
| bool has_crcs) |
| { |
| return strcmp(amagic, bmagic) == 0; |
| } |
| #endif /* CONFIG_MODVERSIONS */ |
| |
| /* Resolve a symbol for this module. I.e. if we find one, record usage. */ |
| static const struct kernel_symbol *resolve_symbol(struct module *mod, |
| const struct load_info *info, |
| const char *name, |
| char ownername[]) |
| { |
| struct module *owner; |
| const struct kernel_symbol *sym; |
| const s32 *crc; |
| int err; |
| |
| /* |
| * The module_mutex should not be a heavily contended lock; |
| * if we get the occasional sleep here, we'll go an extra iteration |
| * in the wait_event_interruptible(), which is harmless. |
| */ |
| sched_annotate_sleep(); |
| mutex_lock(&module_mutex); |
| sym = find_symbol(name, &owner, &crc, |
| !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); |
| if (!sym) |
| goto unlock; |
| |
| if (!check_version(info, name, mod, crc)) { |
| sym = ERR_PTR(-EINVAL); |
| goto getname; |
| } |
| |
| err = ref_module(mod, owner); |
| if (err) { |
| sym = ERR_PTR(err); |
| goto getname; |
| } |
| |
| getname: |
| /* We must make copy under the lock if we failed to get ref. */ |
| strncpy(ownername, module_name(owner), MODULE_NAME_LEN); |
| unlock: |
| mutex_unlock(&module_mutex); |
| return sym; |
| } |
| |
| static const struct kernel_symbol * |
| resolve_symbol_wait(struct module *mod, |
| const struct load_info *info, |
| const char *name) |
| { |
| const struct kernel_symbol *ksym; |
| char owner[MODULE_NAME_LEN]; |
| |
| if (wait_event_interruptible_timeout(module_wq, |
| !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) |
| || PTR_ERR(ksym) != -EBUSY, |
| 30 * HZ) <= 0) { |
| pr_warn("%s: gave up waiting for init of module %s.\n", |
| mod->name, owner); |
| } |
| return ksym; |
| } |
| |
| /* |
| * /sys/module/foo/sections stuff |
| * J. Corbet <corbet@lwn.net> |
| */ |
| #ifdef CONFIG_SYSFS |
| |
| #ifdef CONFIG_KALLSYMS |
| static inline bool sect_empty(const Elf_Shdr *sect) |
| { |
| return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; |
| } |
| |
| struct module_sect_attr { |
| struct bin_attribute battr; |
| unsigned long address; |
| }; |
| |
| struct module_sect_attrs { |
| struct attribute_group grp; |
| unsigned int nsections; |
| struct module_sect_attr attrs[0]; |
| }; |
| |
| #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[0]; |
| }; |
| |
| static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, |
| struct bin_attribute *bin_attr, |
| char *buf, loff_t pos, size_t count) |
| { |
| /* |
| * The caller checked the pos and count against our size. |
| */ |
| memcpy(buf, bin_attr->private + pos, count); |
| return count; |
| } |
| |
| static void free_notes_attrs(struct module_notes_attrs *notes_attrs, |
| unsigned int i) |
| { |
| if (notes_attrs->dir) { |
| while (i-- > 0) |
| sysfs_remove_bin_file(notes_attrs->dir, |
| ¬es_attrs->attrs[i]); |
| kobject_put(notes_attrs->dir); |
| } |
| kfree(notes_attrs); |
| } |
| |
| static void add_notes_attrs(struct module *mod, const struct load_info *info) |
| { |
| unsigned int notes, loaded, i; |
| struct module_notes_attrs *notes_attrs; |
| struct bin_attribute *nattr; |
| |
| /* failed to create section attributes, so can't create notes */ |
| if (!mod->sect_attrs) |
| return; |
| |
| /* Count notes sections and allocate structures. */ |
| notes = 0; |
| for (i = 0; i < info->hdr->e_shnum; i++) |
| if (!sect_empty(&info->sechdrs[i]) && |
| (info->sechdrs[i].sh_type == SHT_NOTE)) |
| ++notes; |
| |
| if (notes == 0) |
| return; |
| |
| notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), |
| GFP_KERNEL); |
| if (notes_attrs == NULL) |
| return; |
| |
| notes_attrs->notes = notes; |
| nattr = ¬es_attrs->attrs[0]; |
| for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { |
| if (sect_empty(&info->sechdrs[i])) |
| continue; |
| if (info->sechdrs[i].sh_type == SHT_NOTE) { |
| sysfs_bin_attr_init(nattr); |
| nattr->attr.name = mod->sect_attrs->attrs[loaded].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); |
| |
| /* delay uevent until full sysfs population */ |
| out: |
| return err; |
| } |
| |
| static int mod_sysfs_setup(struct module *mod, |
| const struct load_info *info, |
| struct kernel_param *kparam, |
| unsigned int num_params) |
| { |
| int err; |
| |
| err = mod_sysfs_init(mod); |
| if (err) |
| goto out; |
| |
| mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); |
| if (!mod->holders_dir) { |
| err = -ENOMEM; |
| goto out_unreg; |
| } |
| |
| err = module_param_sysfs_setup(mod, kparam, num_params); |
| if (err) |
| goto out_unreg_holders; |
| |
| err = module_add_modinfo_attrs(mod); |
| if (err) |
| goto out_unreg_param; |
| |
| err = add_usage_links(mod); |
| if (err) |
| goto out_unreg_modinfo_attrs; |
| |
| add_sect_attrs(mod, info); |
| add_notes_attrs(mod, info); |
| |
| kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); |
| return 0; |
| |
| out_unreg_modinfo_attrs: |
| module_remove_modinfo_attrs(mod, -1); |
| out_unreg_param: |
| module_param_sysfs_remove(mod); |
| out_unreg_holders: |
| kobject_put(mod->holders_dir); |
| out_unreg: |
| mod_kobject_put(mod); |
| out: |
| return err; |
| } |
| |
| static void mod_sysfs_fini(struct module *mod) |
| { |
| remove_notes_attrs(mod); |
| remove_sect_attrs(mod); |
| mod_kobject_put(mod); |
| } |
| |
| static void init_param_lock(struct module *mod) |
| { |
| mutex_init(&mod->param_lock); |
| } |
| #else /* !CONFIG_SYSFS */ |
| |
| static int mod_sysfs_setup(struct module *mod, |
| const struct load_info *info, |
| struct kernel_param *kparam, |
| unsigned int num_params) |
| { |
| return 0; |
| } |
| |
| static void mod_sysfs_fini(struct module *mod) |
| { |
| } |
| |
| static void module_remove_modinfo_attrs(struct module *mod, int end) |
| { |
| } |
| |
| static void del_usage_links(struct module *mod) |
| { |
| } |
| |
| static void init_param_lock(struct module *mod) |
| { |
| } |
| #endif /* CONFIG_SYSFS */ |
| |
| static void mod_sysfs_teardown(struct module *mod) |
| { |
| del_usage_links(mod); |
| module_remove_modinfo_attrs(mod, -1); |
| module_param_sysfs_remove(mod); |
| kobject_put(mod->mkobj.drivers_dir); |
| kobject_put(mod->holders_dir); |
| mod_sysfs_fini(mod); |
| } |
| |
| #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX |
| /* |
| * LKM RO/NX protection: protect module's text/ro-data |
| * from modification and any data from execution. |
| * |
| * General layout of module is: |
| * [text] [read-only-data] [ro-after-init] [writable data] |
| * text_size -----^ ^ ^ ^ |
| * ro_size ------------------------| | | |
| * ro_after_init_size -----------------------------| | |
| * size -----------------------------------------------------------| |
| * |
| * These values are always page-aligned (as is base) |
| */ |
| static void frob_text(const struct module_layout *layout, |
| int (*set_memory)(unsigned long start, int num_pages)) |
| { |
| BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); |
| BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); |
| set_memory((unsigned long)layout->base, |
| layout->text_size >> PAGE_SHIFT); |
| } |
| |
| #ifdef CONFIG_STRICT_MODULE_RWX |
| static void frob_rodata(const struct module_layout *layout, |
| int (*set_memory)(unsigned long start, int num_pages)) |
| { |
| BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); |
| BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); |
| BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); |
| set_memory((unsigned long)layout->base + layout->text_size, |
| (layout->ro_size - layout->text_size) >> PAGE_SHIFT); |
| } |
| |
| static void frob_ro_after_init(const struct module_layout *layout, |
| int (*set_memory)(unsigned long start, int num_pages)) |
| { |
| BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); |
| BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); |
| BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); |
| set_memory((unsigned long)layout->base + layout->ro_size, |
| (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); |
| } |
| |
| static void frob_writable_data(const struct module_layout *layout, |
| int (*set_memory)(unsigned long start, int num_pages)) |
| { |
| BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); |
| BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); |
| BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1)); |
| set_memory((unsigned long)layout->base + layout->ro_after_init_size, |
| (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); |
| } |
| |
| /* livepatching wants to disable read-only so it can frob module. */ |
| void module_disable_ro(const struct module *mod) |
| { |
| if (!rodata_enabled) |
| return; |
| |
| frob_text(&mod->core_layout, set_memory_rw); |
| frob_rodata(&mod->core_layout, set_memory_rw); |
| frob_ro_after_init(&mod->core_layout, set_memory_rw); |
| frob_text(&mod->init_layout, set_memory_rw); |
| frob_rodata(&mod->init_layout, set_memory_rw); |
| } |
| |
| void module_enable_ro(const struct module *mod, bool after_init) |
| { |
| if (!rodata_enabled) |
| return; |
| |
| 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 void module_disable_nx(const struct module *mod) |
| { |
| frob_rodata(&mod->core_layout, set_memory_x); |
| frob_ro_after_init(&mod->core_layout, set_memory_x); |
| frob_writable_data(&mod->core_layout, set_memory_x); |
| frob_rodata(&mod->init_layout, set_memory_x); |
| frob_writable_data(&mod->init_layout, set_memory_x); |
| } |
| |
| /* Iterate through all modules and set each module's text as RW */ |
| void set_all_modules_text_rw(void) |
| { |
| struct module *mod; |
| |
| if (!rodata_enabled) |
| return; |
| |
| mutex_lock(&module_mutex); |
| list_for_each_entry_rcu(mod, &modules, list) { |
| if (mod->state == MODULE_STATE_UNFORMED) |
| continue; |
| |
| frob_text(&mod->core_layout, set_memory_rw); |
| frob_text(&mod->init_layout, set_memory_rw); |
| } |
| mutex_unlock(&module_mutex); |
| } |
| |
| /* Iterate through all modules and set each module's text as RO */ |
| void set_all_modules_text_ro(void) |
| { |
| struct module *mod; |
| |
| if (!rodata_enabled) |
| return; |
| |
| mutex_lock(&module_mutex); |
| list_for_each_entry_rcu(mod, &modules, list) { |
| /* |
| * Ignore going modules since it's possible that ro |
| * protection has already been disabled, otherwise we'll |
| * run into protection faults at module deallocation. |
| */ |
| if (mod->state == MODULE_STATE_UNFORMED || |
| mod->state == MODULE_STATE_GOING) |
| continue; |
| |
| frob_text(&mod->core_layout, set_memory_ro); |
| frob_text(&mod->init_layout, set_memory_ro); |
| } |
| mutex_unlock(&module_mutex); |
| } |
| |
| static void disable_ro_nx(const struct module_layout *layout) |
| { |
| if (rodata_enabled) { |
| frob_text(layout, set_memory_rw); |
| frob_rodata(layout, set_memory_rw); |
| frob_ro_after_init(layout, set_memory_rw); |
| } |
| frob_rodata(layout, set_memory_x); |
| frob_ro_after_init(layout, set_memory_x); |
| frob_writable_data(layout, set_memory_x); |
| } |
| |
| #else /* !CONFIG_STRICT_MODULE_RWX */ |
| static void disable_ro_nx(const struct module_layout *layout) { } |
| static void module_enable_nx(const struct module *mod) { } |
| static void module_disable_nx(const struct module *mod) { } |
| #endif /* CONFIG_STRICT_MODULE_RWX */ |
| |
| static void module_enable_x(const struct module *mod) |
| { |
| frob_text(&mod->core_layout, set_memory_x); |
| frob_text(&mod->init_layout, set_memory_x); |
| } |
| #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ |
| static void disable_ro_nx(const struct module_layout *layout) { } |
| static void module_enable_nx(const struct module *mod) { } |
| static void module_disable_nx(const struct module *mod) { } |
| static void module_enable_x(const struct module *mod) { } |
| #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ |
| |
| #ifdef CONFIG_LIVEPATCH |
| /* |
| * Persist Elf information about a module. Copy the Elf header, |
| * section header table, section string table, and symtab section |
| * index from info to mod->klp_info. |
| */ |
| static int copy_module_elf(struct module *mod, struct load_info *info) |
| { |
| unsigned int size, symndx; |
| int ret; |
| |
| size = sizeof(*mod->klp_info); |
| mod->klp_info = kmalloc(size, GFP_KERNEL); |
| if (mod->klp_info == NULL) |
| return -ENOMEM; |
| |
| /* Elf header */ |
| size = sizeof(mod->klp_info->hdr); |
| memcpy(&mod->klp_info->hdr, info->hdr, size); |
| |
| /* Elf section header table */ |
| size = sizeof(*info->sechdrs) * info->hdr->e_shnum; |
| mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL); |
| if (mod->klp_info->sechdrs == NULL) { |
| ret = -ENOMEM; |
| goto free_info; |
| } |
| |
| /* Elf section name string table */ |
| size = info->sechdrs[info->hdr->e_shstrndx].sh_size; |
| mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL); |
| if (mod->klp_info->secstrings == NULL) { |
| ret = -ENOMEM; |
| goto free_sechdrs; |
| } |
| |
| /* Elf symbol section index */ |
| symndx = info->index.sym; |
| mod->klp_info->symndx = symndx; |
| |
| /* |
| * For livepatch modules, core_kallsyms.symtab is a complete |
| * copy of the original symbol table. Adjust sh_addr to point |
| * to core_kallsyms.symtab since the copy of the symtab in module |
| * init memory is freed at the end of do_init_module(). |
| */ |
| mod->klp_info->sechdrs[symndx].sh_addr = \ |
| (unsigned long) mod->core_kallsyms.symtab; |
| |
| return 0; |
| |
| free_sechdrs: |
| kfree(mod->klp_info->sechdrs); |
| free_info: |
| kfree(mod->klp_info); |
| return ret; |
| } |
| |
| static void free_module_elf(struct module *mod) |
| { |
| kfree(mod->klp_info->sechdrs); |
| kfree(mod->klp_info->secstrings); |
| kfree(mod->klp_info); |
| } |
| #else /* !CONFIG_LIVEPATCH */ |
| static int copy_module_elf(struct module *mod, struct load_info *info) |
| { |
| return 0; |
| } |
| |
| static void free_module_elf(struct module *mod) |
| { |
| } |
| #endif /* CONFIG_LIVEPATCH */ |
| |
| void __weak module_memfree(void *module_region) |
| { |
| 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_sched(); |
| mutex_unlock(&module_mutex); |
| |
| /* This may be empty, but that's OK */ |
| disable_ro_nx(&mod->init_layout); |
| |
| /* Clean up CFI for the module. */ |
| cfi_cleanup(mod); |
| |
| module_arch_freeing_init(mod); |
| module_memfree(mod->init_layout.base); |
| kfree(mod->args); |
| percpu_modfree(mod); |
| |
| /* Free lock-classes; relies on the preceding sync_rcu(). */ |
| lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); |
| |
| /* Finally, free the core (containing the module structure) */ |
| disable_ro_nx(&mod->core_layout); |
| module_memfree(mod->core_layout.base); |
| } |
| |
| void *__symbol_get(const char *symbol) |
| { |
| struct module *owner; |
| const struct kernel_symbol *sym; |
| |
| preempt_disable(); |
| sym = find_symbol(symbol, &owner, NULL, true, true); |
| if (sym && strong_try_module_get(owner)) |
| sym = NULL; |
| preempt_enable(); |
| |
| return sym ? (void *)kernel_symbol_value(sym) : NULL; |
| } |
| EXPORT_SYMBOL_GPL(__symbol_get); |
| |
| /* |
| * Ensure that an exported symbol [global namespace] does not already exist |
| * in the kernel or in some other module's exported symbol table. |
| * |
| * You must hold the module_mutex. |
| */ |
| static int verify_export_symbols(struct module *mod) |
| { |
| unsigned int i; |
| struct module *owner; |
| const struct kernel_symbol *s; |
| struct { |
| const struct kernel_symbol *sym; |
| unsigned int num; |
| } arr[] = { |
| { mod->syms, mod->num_syms }, |
| { mod->gpl_syms, mod->num_gpl_syms }, |
| { mod->gpl_future_syms, mod->num_gpl_future_syms }, |
| #ifdef CONFIG_UNUSED_SYMBOLS |
| { mod->unused_syms, mod->num_unused_syms }, |
| { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, |
| #endif |
| }; |
| |
| for (i = 0; i < ARRAY_SIZE(arr); i++) { |
| for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { |
| if (find_symbol(kernel_symbol_name(s), &owner, NULL, |
| true, false)) { |
| pr_err("%s: exports duplicate symbol %s" |
| " (owned by %s)\n", |
| mod->name, kernel_symbol_name(s), |
| module_name(owner)); |
| return -ENOEXEC; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /* Change all symbols so that st_value encodes the pointer directly. */ |
| static int simplify_symbols(struct module *mod, const struct load_info *info) |
| { |
| Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; |
| Elf_Sym *sym = (void *)symsec->sh_addr; |
| unsigned long secbase; |
| unsigned int i; |
| int ret = 0; |
| const struct kernel_symbol *ksym; |
| |
| for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { |
| const char *name = info->strtab + sym[i].st_name; |
| |
| switch (sym[i].st_shndx) { |
| case SHN_COMMON: |
| /* Ignore common symbols */ |
| if (!strncmp(name, "__gnu_lto", 9)) |
| break; |
| |
| /* We compiled with -fno-common. These are not |
| supposed to happen. */ |
| pr_debug("Common symbol: %s\n", name); |
| pr_warn("%s: please compile with -fno-common\n", |
| mod->name); |
| ret = -ENOEXEC; |
| break; |
| |
| case SHN_ABS: |
| /* Don't need to do anything */ |
| pr_debug("Absolute symbol: 0x%08lx\n", |
| (long)sym[i].st_value); |
| break; |
| |
| case SHN_LIVEPATCH: |
| /* Livepatch symbols are resolved by livepatch */ |
| break; |
| |
| case SHN_UNDEF: |
| ksym = resolve_symbol_wait(mod, info, name); |
| /* Ok if resolved. */ |
| if (ksym && !IS_ERR(ksym)) { |
| sym[i].st_value = kernel_symbol_value(ksym); |
| break; |
| } |
| |
| /* Ok if weak. */ |
| if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK) |
| break; |
| |
| ret = PTR_ERR(ksym) ?: -ENOENT; |
| pr_warn("%s: Unknown symbol %s (err %d)\n", |
| mod->name, name, ret); |
| break; |
| |
| default: |
| /* Divert to percpu allocation if a percpu var. */ |
| if (sym[i].st_shndx == info->index.pcpu) |
| secbase = (unsigned long)mod_percpu(mod); |
| else |
| secbase = info->sechdrs[sym[i].st_shndx].sh_addr; |
| sym[i].st_value += secbase; |
| break; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int apply_relocations(struct module *mod, const struct load_info *info) |
| { |
| unsigned int i; |
| int err = 0; |
| |
| /* Now do relocations. */ |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| unsigned int infosec = info->sechdrs[i].sh_info; |
| |
| /* Not a valid relocation section? */ |
| if (infosec >= info->hdr->e_shnum) |
| continue; |
| |
| /* Don't bother with non-allocated sections */ |
| if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) |
| continue; |
| |
| /* Livepatch relocation sections are applied by livepatch */ |
| if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) |
| continue; |
| |
| if (info->sechdrs[i].sh_type == SHT_REL) |
| err = apply_relocate(info->sechdrs, info->strtab, |
| info->index.sym, i, mod); |
| else if (info->sechdrs[i].sh_type == SHT_RELA) |
| err = apply_relocate_add(info->sechdrs, info->strtab, |
| info->index.sym, i, mod); |
| if (err < 0) |
| break; |
| } |
| return err; |
| } |
| |
| /* Additional bytes needed by arch in front of individual sections */ |
| unsigned int __weak arch_mod_section_prepend(struct module *mod, |
| unsigned int section) |
| { |
| /* default implementation just returns zero */ |
| return 0; |
| } |
| |
| /* Update size with this section: return offset. */ |
| static long get_offset(struct module *mod, unsigned int *size, |
| Elf_Shdr *sechdr, unsigned int section) |
| { |
| long ret; |
| |
| *size += arch_mod_section_prepend(mod, section); |
| ret = ALIGN(*size, sechdr->sh_addralign ?: 1); |
| *size = ret + sechdr->sh_size; |
| return ret; |
| } |
| |
| /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld |
| might -- code, read-only data, read-write data, small data. Tally |
| sizes, and place the offsets into sh_entsize fields: high bit means it |
| belongs in init. */ |
| static void layout_sections(struct module *mod, struct load_info *info) |
| { |
| static unsigned long const masks[][2] = { |
| /* NOTE: all executable code must be the first section |
| * in this array; otherwise modify the text_size |
| * finder in the two loops below */ |
| { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, |
| { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, |
| { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, |
| { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, |
| { ARCH_SHF_SMALL | SHF_ALLOC, 0 } |
| }; |
| unsigned int m, i; |
| |
| for (i = 0; i < info->hdr->e_shnum; i++) |
| info->sechdrs[i].sh_entsize = ~0UL; |
| |
| pr_debug("Core section allocation order:\n"); |
| for (m = 0; m < ARRAY_SIZE(masks); ++m) { |
| for (i = 0; i < info->hdr->e_shnum; ++i) { |
| Elf_Shdr *s = &info->sechdrs[i]; |
| const char *sname = info->secstrings + s->sh_name; |
| |
| if ((s->sh_flags & masks[m][0]) != masks[m][0] |
| || (s->sh_flags & masks[m][1]) |
| || s->sh_entsize != ~0UL |
| || strstarts(sname, ".init")) |
| continue; |
| s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i); |
| pr_debug("\t%s\n", sname); |
| } |
| switch (m) { |
| case 0: /* executable */ |
| mod->core_layout.size = debug_align(mod->core_layout.size); |
| mod->core_layout.text_size = mod->core_layout.size; |
| break; |
| case 1: /* RO: text and ro-data */ |
| mod->core_layout.size = debug_align(mod->core_layout.size); |
| mod->core_layout.ro_size = mod->core_layout.size; |
| break; |
| case 2: /* RO after init */ |
| mod->core_layout.size = debug_align(mod->core_layout.size); |
| mod->core_layout.ro_after_init_size = mod->core_layout.size; |
| break; |
| case 4: /* whole core */ |
| mod->core_layout.size = debug_align(mod->core_layout.size); |
| break; |
| } |
| } |
| |
| pr_debug("Init section allocation order:\n"); |
| for (m = 0; m < ARRAY_SIZE(masks); ++m) { |
| for (i = 0; i < info->hdr->e_shnum; ++i) { |
| Elf_Shdr *s = &info->sechdrs[i]; |
| const char *sname = info->secstrings + s->sh_name; |
| |
| if ((s->sh_flags & masks[m][0]) != masks[m][0] |
| || (s->sh_flags & masks[m][1]) |
| || s->sh_entsize != ~0UL |
| || !strstarts(sname, ".init")) |
| continue; |
| s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i) |
| | INIT_OFFSET_MASK); |
| pr_debug("\t%s\n", sname); |
| } |
| switch (m) { |
| case 0: /* executable */ |
| mod->init_layout.size = debug_align(mod->init_layout.size); |
| mod->init_layout.text_size = mod->init_layout.size; |
| break; |
| case 1: /* RO: text and ro-data */ |
| mod->init_layout.size = debug_align(mod->init_layout.size); |
| mod->init_layout.ro_size = mod->init_layout.size; |
| break; |
| case 2: |
| /* |
| * RO after init doesn't apply to init_layout (only |
| * core_layout), so it just takes the value of ro_size. |
| */ |
| mod->init_layout.ro_after_init_size = mod->init_layout.ro_size; |
| break; |
| case 4: /* whole init */ |
| mod->init_layout.size = debug_align(mod->init_layout.size); |
| break; |
| } |
| } |
| } |
| |
| static void set_license(struct module *mod, const char *license) |
| { |
| if (!license) |
| license = "unspecified"; |
| |
| if (!license_is_gpl_compatible(license)) { |
| if (!test_taint(TAINT_PROPRIETARY_MODULE)) |
| pr_warn("%s: module license '%s' taints kernel.\n", |
| mod->name, license); |
| add_taint_module(mod, TAINT_PROPRIETARY_MODULE, |
| LOCKDEP_NOW_UNRELIABLE); |
| } |
| } |
| |
| /* Parse tag=value strings from .modinfo section */ |
| static char *next_string(char *string, unsigned long *secsize) |
| { |
| /* Skip non-zero chars */ |
| while (string[0]) { |
| string++; |
| if ((*secsize)-- <= 1) |
| return NULL; |
| } |
| |
| /* Skip any zero padding. */ |
| while (!string[0]) { |
| string++; |
| if ((*secsize)-- <= 1) |
| return NULL; |
| } |
| return string; |
| } |
| |
| static char *get_modinfo(struct load_info *info, const char *tag) |
| { |
| 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! |
| */ |
| for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) { |
| if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') |
| return p + taglen + 1; |
| } |
| return 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 symbol in given range of kernel_symbols */ |
| static const struct kernel_symbol *lookup_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_symbol(name, __start___ksymtab, __stop___ksymtab); |
| else |
| ks = lookup_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; |
| 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); |
| 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; |
| |
| /* Set types up while we still have access to sections. */ |
| for (i = 0; i < mod->kallsyms->num_symtab; i++) |
| mod->kallsyms->symtab[i].st_info |
| = elf_type(&mod->kallsyms->symtab[i], info); |
| |
| /* Now populate the cut down core kallsyms for after init. */ |
| mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs; |
| mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs; |
| src = mod->kallsyms->symtab; |
| for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) { |
| if (i == 0 || is_livepatch_module(mod) || |
| is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, |
| info->index.pcpu)) { |
| dst[ndst] = src[i]; |
| dst[ndst++].st_name = s - mod->core_kallsyms.strtab; |
| s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name], |
| KSYM_NAME_LEN) + 1; |
| } |
| } |
| mod->core_kallsyms.num_symtab = ndst; |
| } |
| #else |
| static inline void layout_symtab(struct module *mod, struct load_info *info) |
| { |
| } |
| |
| static void add_kallsyms(struct module *mod, const struct load_info *info) |
| { |
| } |
| #endif /* CONFIG_KALLSYMS */ |
| |
| static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num) |
| { |
| if (!debug) |
| return; |
| #ifdef CONFIG_DYNAMIC_DEBUG |
| if (ddebug_add_module(debug, num, mod->name)) |
| pr_err("dynamic debug error adding module: %s\n", |
| debug->modname); |
| #endif |
| } |
| |
| static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) |
| { |
| if (debug) |
| ddebug_remove_module(mod->name); |
| } |
| |
| void * __weak module_alloc(unsigned long size) |
| { |
| return vmalloc_exec(size); |
| } |
| |
| #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 = -ENOKEY; |
| const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; |
| 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; |
| } |
| |
| /* Not having a signature is only an error if we're strict. */ |
| if (err == -ENOKEY && !is_module_sig_enforced()) |
| err = 0; |
| |
| return err; |
| } |
| #else /* !CONFIG_MODULE_SIG */ |
| static int module_sig_check(struct load_info *info, int flags) |
| { |
| return 0; |
| } |
| #endif /* !CONFIG_MODULE_SIG */ |
| |
| /* Sanity checks against invalid binaries, wrong arch, weird elf version. */ |
| static int elf_header_check(struct load_info *info) |
| { |
| if (info->len < sizeof(*(info->hdr))) |
| return -ENOEXEC; |
| |
| if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0 |
| || info->hdr->e_type != ET_REL |
| || !elf_check_arch(info->hdr) |
| || info->hdr->e_shentsize != sizeof(Elf_Shdr)) |
| return -ENOEXEC; |
| |
| if (info->hdr->e_shoff >= info->len |
| || (info->hdr->e_shnum * sizeof(Elf_Shdr) > |
| info->len - info->hdr->e_shoff)) |
| return -ENOEXEC; |
| |
| return 0; |
| } |
| |
| #define COPY_CHUNK_SIZE (16*PAGE_SIZE) |
| |
| static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len) |
| { |
| do { |
| unsigned long n = min(len, COPY_CHUNK_SIZE); |
| |
| if (copy_from_user(dst, usrc, n) != 0) |
| return -EFAULT; |
| cond_resched(); |
| dst += n; |
| usrc += n; |
| len -= n; |
| } while (len); |
| return 0; |
| } |
| |
| #ifdef CONFIG_LIVEPATCH |
| static int check_modinfo_livepatch(struct module *mod, struct load_info *info) |
| { |
| if (get_modinfo(info, "livepatch")) { |
| mod->klp = true; |
| add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); |
| pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n", |
| mod->name); |
| } |
| |
| return 0; |
| } |
| #else /* !CONFIG_LIVEPATCH */ |
| static int check_modinfo_livepatch(struct module *mod, struct load_info *info) |
| { |
| if (get_modinfo(info, "livepatch")) { |
| pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", |
| mod->name); |
| return -ENOEXEC; |
| } |
| |
| return 0; |
| } |
| #endif /* CONFIG_LIVEPATCH */ |
| |
| static void check_modinfo_retpoline(struct module *mod, struct load_info *info) |
| { |
| if (retpoline_module_ok(get_modinfo(info, "retpoline"))) |
| return; |
| |
| pr_warn("%s: loading module not compiled with retpoline compiler.\n", |
| mod->name); |
| } |
| |
| /* Sets info->hdr and info->len. */ |
| static int copy_module_from_user(const void __user *umod, unsigned long len, |
| struct load_info *info) |
| { |
| int err; |
| |
| info->len = len; |
| if (info->len < sizeof(*(info->hdr))) |
| return -ENOEXEC; |
| |
| err = security_kernel_load_data(LOADING_MODULE); |
| if (err) |
| return err; |
| |
| /* Suck in entire file: we'll want most of it. */ |
| info->hdr = __vmalloc(info->len, |
| GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL); |
| if (!info->hdr) |
| return -ENOMEM; |
| |
| if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { |
| vfree(info->hdr); |
| return -EFAULT; |
| } |
| |
| return 0; |
| } |
| |
| static void free_copy(struct load_info *info) |
| { |
| vfree(info->hdr); |
| } |
| |
| static int rewrite_section_headers(struct load_info *info, int flags) |
| { |
| unsigned int i; |
| |
| /* This should always be true, but let's be sure. */ |
| info->sechdrs[0].sh_addr = 0; |
| |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| Elf_Shdr *shdr = &info->sechdrs[i]; |
| if (shdr->sh_type != SHT_NOBITS |
| && info->len < shdr->sh_offset + shdr->sh_size) { |
| pr_err("Module len %lu truncated\n", info->len); |
| return -ENOEXEC; |
| } |
| |
| /* Mark all sections sh_addr with their address in the |
| temporary image. */ |
| shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; |
| |
| #ifndef CONFIG_MODULE_UNLOAD |
| /* Don't load .exit sections */ |
| if (strstarts(info->secstrings+shdr->sh_name, ".exit")) |
| shdr->sh_flags &= ~(unsigned long)SHF_ALLOC; |
| #endif |
| } |
| |
| /* Track but don't keep modinfo and version sections. */ |
| info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; |
| info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; |
| |
| return 0; |
| } |
| |
| /* |
| * Set up our basic convenience variables (pointers to section headers, |
| * search for module section index etc), and do some basic section |
| * verification. |
| * |
| * Set info->mod to the temporary copy of the module in info->hdr. The final one |
| * will be allocated in move_module(). |
| */ |
| static int setup_load_info(struct load_info *info, int flags) |
| { |
| unsigned int i; |
| |
| /* Set up the convenience variables */ |
| info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; |
| info->secstrings = (void *)info->hdr |
| + info->sechdrs[info->hdr->e_shstrndx].sh_offset; |
| |
| /* Try to find a name early so we can log errors with a module name */ |
| info->index.info = find_sec(info, ".modinfo"); |
| if (info->index.info) |
| info->name = get_modinfo(info, "name"); |
| |
| /* Find internal symbols and strings. */ |
| for (i = 1; i < info->hdr->e_shnum; i++) { |
| if (info->sechdrs[i].sh_type == SHT_SYMTAB) { |
| info->index.sym = i; |
| info->index.str = info->sechdrs[i].sh_link; |
| info->strtab = (char *)info->hdr |
| + info->sechdrs[info->index.str].sh_offset; |
| break; |
| } |
| } |
| |
| if (info->index.sym == 0) { |
| pr_warn("%s: module has no symbols (stripped?)\n", |
| info->name ?: "(missing .modinfo section or name field)"); |
| return -ENOEXEC; |
| } |
| |
|