TOMOYO Linux Cross Reference
Linux/kernel/module/main.c

   // SPDX-License-Identifier: GPL-2.0-or-later
   /*
    * Copyright (C) 2002 Richard Henderson
    * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
    * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
    */
   
   #define INCLUDE_VERMAGIC
   
  #include <linux/export.h>
  #include <linux/extable.h>
  #include <linux/moduleloader.h>
  #include <linux/module_signature.h>
  #include <linux/trace_events.h>
  #include <linux/init.h>
  #include <linux/kallsyms.h>
  #include <linux/buildid.h>
  #include <linux/fs.h>
  #include <linux/kernel.h>
  #include <linux/kernel_read_file.h>
  #include <linux/kstrtox.h>
  #include <linux/slab.h>
  #include <linux/vmalloc.h>
  #include <linux/elf.h>
  #include <linux/seq_file.h>
  #include <linux/syscalls.h>
  #include <linux/fcntl.h>
  #include <linux/rcupdate.h>
  #include <linux/capability.h>
  #include <linux/cpu.h>
  #include <linux/moduleparam.h>
  #include <linux/errno.h>
  #include <linux/err.h>
  #include <linux/vermagic.h>
  #include <linux/notifier.h>
  #include <linux/sched.h>
  #include <linux/device.h>
  #include <linux/string.h>
  #include <linux/mutex.h>
  #include <linux/rculist.h>
  #include <linux/uaccess.h>
  #include <asm/cacheflush.h>
  #include <linux/set_memory.h>
  #include <asm/mmu_context.h>
  #include <linux/license.h>
  #include <asm/sections.h>
  #include <linux/tracepoint.h>
  #include <linux/ftrace.h>
  #include <linux/livepatch.h>
  #include <linux/async.h>
  #include <linux/percpu.h>
  #include <linux/kmemleak.h>
  #include <linux/jump_label.h>
  #include <linux/pfn.h>
  #include <linux/bsearch.h>
  #include <linux/dynamic_debug.h>
  #include <linux/audit.h>
  #include <linux/cfi.h>
  #include <linux/codetag.h>
  #include <linux/debugfs.h>
  #include <linux/execmem.h>
  #include <uapi/linux/module.h>
  #include "internal.h"
  
  #define CREATE_TRACE_POINTS
  #include <trace/events/module.h>
  #include <linux/ccsecurity.h>
  
  /*
   * Mutex protects:
   * 1) List of modules (also safely readable with preempt_disable),
   * 2) module_use links,
   * 3) mod_tree.addr_min/mod_tree.addr_max.
   * (delete and add uses RCU list operations).
   */
  DEFINE_MUTEX(module_mutex);
  LIST_HEAD(modules);
  
  /* Work queue for freeing init sections in success case */
  static void do_free_init(struct work_struct *w);
  static DECLARE_WORK(init_free_wq, do_free_init);
  static LLIST_HEAD(init_free_list);
  
  struct mod_tree_root mod_tree __cacheline_aligned = {
          .addr_min = -1UL,
  };
  
  struct symsearch {
          const struct kernel_symbol *start, *stop;
          const s32 *crcs;
          enum mod_license license;
  };
  
  /*
   * Bounds of module memory, for speeding up __module_address.
   * Protected by module_mutex.
   */
  static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base,
                                  unsigned int size, struct mod_tree_root *tree)
 {
         unsigned long min = (unsigned long)base;
         unsigned long max = min + size;
 
 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
         if (mod_mem_type_is_core_data(type)) {
                 if (min < tree->data_addr_min)
                         tree->data_addr_min = min;
                 if (max > tree->data_addr_max)
                         tree->data_addr_max = max;
                 return;
         }
 #endif
         if (min < tree->addr_min)
                 tree->addr_min = min;
         if (max > tree->addr_max)
                 tree->addr_max = max;
 }
 
 static void mod_update_bounds(struct module *mod)
 {
         for_each_mod_mem_type(type) {
                 struct module_memory *mod_mem = &mod->mem[type];
 
                 if (mod_mem->size)
                         __mod_update_bounds(type, mod_mem->base, mod_mem->size, &mod_tree);
         }
 }
 
 /* Block module loading/unloading? */
 int modules_disabled;
 core_param(nomodule, modules_disabled, bint, 0);
 
 /* Waiting for a module to finish initializing? */
 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
 
 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
 
 int register_module_notifier(struct notifier_block *nb)
 {
         return blocking_notifier_chain_register(&module_notify_list, nb);
 }
 EXPORT_SYMBOL(register_module_notifier);
 
 int unregister_module_notifier(struct notifier_block *nb)
 {
         return blocking_notifier_chain_unregister(&module_notify_list, nb);
 }
 EXPORT_SYMBOL(unregister_module_notifier);
 
 /*
  * We require a truly strong try_module_get(): 0 means success.
  * Otherwise an error is returned due to ongoing or failed
  * initialization etc.
  */
 static inline int strong_try_module_get(struct module *mod)
 {
         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
         if (mod && mod->state == MODULE_STATE_COMING)
                 return -EBUSY;
         if (try_module_get(mod))
                 return 0;
         else
                 return -ENOENT;
 }
 
 static inline void add_taint_module(struct module *mod, unsigned flag,
                                     enum lockdep_ok lockdep_ok)
 {
         add_taint(flag, lockdep_ok);
         set_bit(flag, &mod->taints);
 }
 
 /*
  * A thread that wants to hold a reference to a module only while it
  * is running can call this to safely exit.
  */
 void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
 {
         module_put(mod);
         kthread_exit(code);
 }
 EXPORT_SYMBOL(__module_put_and_kthread_exit);
 
 /* Find a module section: 0 means not found. */
 static unsigned int find_sec(const struct load_info *info, const char *name)
 {
         unsigned int i;
 
         for (i = 1; i < info->hdr->e_shnum; i++) {
                 Elf_Shdr *shdr = &info->sechdrs[i];
                 /* Alloc bit cleared means "ignore it." */
                 if ((shdr->sh_flags & SHF_ALLOC)
                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
                         return i;
         }
         return 0;
 }
 
 /* Find a module section, or NULL. */
 static void *section_addr(const struct load_info *info, const char *name)
 {
         /* Section 0 has sh_addr 0. */
         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
 }
 
 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
 static void *section_objs(const struct load_info *info,
                           const char *name,
                           size_t object_size,
                           unsigned int *num)
 {
         unsigned int sec = find_sec(info, name);
 
         /* Section 0 has sh_addr 0 and sh_size 0. */
         *num = info->sechdrs[sec].sh_size / object_size;
         return (void *)info->sechdrs[sec].sh_addr;
 }
 
 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
 static unsigned int find_any_sec(const struct load_info *info, const char *name)
 {
         unsigned int i;
 
         for (i = 1; i < info->hdr->e_shnum; i++) {
                 Elf_Shdr *shdr = &info->sechdrs[i];
                 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
                         return i;
         }
         return 0;
 }
 
 /*
  * Find a module section, or NULL. Fill in number of "objects" in section.
  * Ignores SHF_ALLOC flag.
  */
 static __maybe_unused void *any_section_objs(const struct load_info *info,
                                              const char *name,
                                              size_t object_size,
                                              unsigned int *num)
 {
         unsigned int sec = find_any_sec(info, name);
 
         /* Section 0 has sh_addr 0 and sh_size 0. */
         *num = info->sechdrs[sec].sh_size / object_size;
         return (void *)info->sechdrs[sec].sh_addr;
 }
 
 #ifndef CONFIG_MODVERSIONS
 #define symversion(base, idx) NULL
 #else
 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
 #endif
 
 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
 {
 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
         return offset_to_ptr(&sym->name_offset);
 #else
         return sym->name;
 #endif
 }
 
 static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
 {
 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
         if (!sym->namespace_offset)
                 return NULL;
         return offset_to_ptr(&sym->namespace_offset);
 #else
         return sym->namespace;
 #endif
 }
 
 int cmp_name(const void *name, const void *sym)
 {
         return strcmp(name, kernel_symbol_name(sym));
 }
 
 static bool find_exported_symbol_in_section(const struct symsearch *syms,
                                             struct module *owner,
                                             struct find_symbol_arg *fsa)
 {
         struct kernel_symbol *sym;
 
         if (!fsa->gplok && syms->license == GPL_ONLY)
                 return false;
 
         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
                         sizeof(struct kernel_symbol), cmp_name);
         if (!sym)
                 return false;
 
         fsa->owner = owner;
         fsa->crc = symversion(syms->crcs, sym - syms->start);
         fsa->sym = sym;
         fsa->license = syms->license;
 
         return true;
 }
 
 /*
  * Find an exported symbol and return it, along with, (optional) crc and
  * (optional) module which owns it.  Needs preempt disabled or module_mutex.
  */
 bool find_symbol(struct find_symbol_arg *fsa)
 {
         static const struct symsearch arr[] = {
                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
                   NOT_GPL_ONLY },
                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
                   __start___kcrctab_gpl,
                   GPL_ONLY },
         };
         struct module *mod;
         unsigned int i;
 
         module_assert_mutex_or_preempt();
 
         for (i = 0; i < ARRAY_SIZE(arr); i++)
                 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
                         return true;
 
         list_for_each_entry_rcu(mod, &modules, list,
                                 lockdep_is_held(&module_mutex)) {
                 struct symsearch arr[] = {
                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
                           NOT_GPL_ONLY },
                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
                           mod->gpl_crcs,
                           GPL_ONLY },
                 };
 
                 if (mod->state == MODULE_STATE_UNFORMED)
                         continue;
 
                 for (i = 0; i < ARRAY_SIZE(arr); i++)
                         if (find_exported_symbol_in_section(&arr[i], mod, fsa))
                                 return true;
         }
 
         pr_debug("Failed to find symbol %s\n", fsa->name);
         return false;
 }
 
 /*
  * Search for module by name: must hold module_mutex (or preempt disabled
  * for read-only access).
  */
 struct module *find_module_all(const char *name, size_t len,
                                bool even_unformed)
 {
         struct module *mod;
 
         module_assert_mutex_or_preempt();
 
         list_for_each_entry_rcu(mod, &modules, list,
                                 lockdep_is_held(&module_mutex)) {
                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
                         continue;
                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
                         return mod;
         }
         return NULL;
 }
 
 struct module *find_module(const char *name)
 {
         return find_module_all(name, strlen(name), false);
 }
 
 #ifdef CONFIG_SMP
 
 static inline void __percpu *mod_percpu(struct module *mod)
 {
         return mod->percpu;
 }
 
 static int percpu_modalloc(struct module *mod, struct load_info *info)
 {
         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
         unsigned long align = pcpusec->sh_addralign;
 
         if (!pcpusec->sh_size)
                 return 0;
 
         if (align > PAGE_SIZE) {
                 pr_warn("%s: per-cpu alignment %li > %li\n",
                         mod->name, align, PAGE_SIZE);
                 align = PAGE_SIZE;
         }
 
         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
         if (!mod->percpu) {
                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
                         mod->name, (unsigned long)pcpusec->sh_size);
                 return -ENOMEM;
         }
         mod->percpu_size = pcpusec->sh_size;
         return 0;
 }
 
 static void percpu_modfree(struct module *mod)
 {
         free_percpu(mod->percpu);
 }
 
 static unsigned int find_pcpusec(struct load_info *info)
 {
         return find_sec(info, ".data..percpu");
 }
 
 static void percpu_modcopy(struct module *mod,
                            const void *from, unsigned long size)
 {
         int cpu;
 
         for_each_possible_cpu(cpu)
                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
 }
 
 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
 {
         struct module *mod;
         unsigned int cpu;
 
         preempt_disable();
 
         list_for_each_entry_rcu(mod, &modules, list) {
                 if (mod->state == MODULE_STATE_UNFORMED)
                         continue;
                 if (!mod->percpu_size)
                         continue;
                 for_each_possible_cpu(cpu) {
                         void *start = per_cpu_ptr(mod->percpu, cpu);
                         void *va = (void *)addr;
 
                         if (va >= start && va < start + mod->percpu_size) {
                                 if (can_addr) {
                                         *can_addr = (unsigned long) (va - start);
                                         *can_addr += (unsigned long)
                                                 per_cpu_ptr(mod->percpu,
                                                             get_boot_cpu_id());
                                 }
                                 preempt_enable();
                                 return true;
                         }
                 }
         }
 
         preempt_enable();
         return false;
 }
 
 /**
  * is_module_percpu_address() - test whether address is from module static percpu
  * @addr: address to test
  *
  * Test whether @addr belongs to module static percpu area.
  *
  * Return: %true if @addr is from module static percpu area
  */
 bool is_module_percpu_address(unsigned long addr)
 {
         return __is_module_percpu_address(addr, NULL);
 }
 
 #else /* ... !CONFIG_SMP */
 
 static inline void __percpu *mod_percpu(struct module *mod)
 {
         return NULL;
 }
 static int percpu_modalloc(struct module *mod, struct load_info *info)
 {
         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
         if (info->sechdrs[info->index.pcpu].sh_size != 0)
                 return -ENOMEM;
         return 0;
 }
 static inline void percpu_modfree(struct module *mod)
 {
 }
 static unsigned int find_pcpusec(struct load_info *info)
 {
         return 0;
 }
 static inline void percpu_modcopy(struct module *mod,
                                   const void *from, unsigned long size)
 {
         /* pcpusec should be 0, and size of that section should be 0. */
         BUG_ON(size != 0);
 }
 bool is_module_percpu_address(unsigned long addr)
 {
         return false;
 }
 
 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
 {
         return false;
 }
 
 #endif /* CONFIG_SMP */
 
 #define MODINFO_ATTR(field)     \
 static void setup_modinfo_##field(struct module *mod, const char *s)  \
 {                                                                     \
         mod->field = kstrdup(s, GFP_KERNEL);                          \
 }                                                                     \
 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
                         struct module_kobject *mk, char *buffer)      \
 {                                                                     \
         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
 }                                                                     \
 static int modinfo_##field##_exists(struct module *mod)               \
 {                                                                     \
         return mod->field != NULL;                                    \
 }                                                                     \
 static void free_modinfo_##field(struct module *mod)                  \
 {                                                                     \
         kfree(mod->field);                                            \
         mod->field = NULL;                                            \
 }                                                                     \
 static struct module_attribute modinfo_##field = {                    \
         .attr = { .name = __stringify(field), .mode = 0444 },         \
         .show = show_modinfo_##field,                                 \
         .setup = setup_modinfo_##field,                               \
         .test = modinfo_##field##_exists,                             \
         .free = free_modinfo_##field,                                 \
 };
 
 MODINFO_ATTR(version);
 MODINFO_ATTR(srcversion);
 
 static struct {
         char name[MODULE_NAME_LEN + 1];
         char taints[MODULE_FLAGS_BUF_SIZE];
 } last_unloaded_module;
 
 #ifdef CONFIG_MODULE_UNLOAD
 
 EXPORT_TRACEPOINT_SYMBOL(module_get);
 
 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
 #define MODULE_REF_BASE 1
 
 /* Init the unload section of the module. */
 static int module_unload_init(struct module *mod)
 {
         /*
          * Initialize reference counter to MODULE_REF_BASE.
          * refcnt == 0 means module is going.
          */
         atomic_set(&mod->refcnt, MODULE_REF_BASE);
 
         INIT_LIST_HEAD(&mod->source_list);
         INIT_LIST_HEAD(&mod->target_list);
 
         /* Hold reference count during initialization. */
         atomic_inc(&mod->refcnt);
 
         return 0;
 }
 
 /* Does a already use b? */
 static int already_uses(struct module *a, struct module *b)
 {
         struct module_use *use;
 
         list_for_each_entry(use, &b->source_list, source_list) {
                 if (use->source == a)
                         return 1;
         }
         pr_debug("%s does not use %s!\n", a->name, b->name);
         return 0;
 }
 
 /*
  * Module a uses b
  *  - we add 'a' as a "source", 'b' as a "target" of module use
  *  - the module_use is added to the list of 'b' sources (so
  *    'b' can walk the list to see who sourced them), and of 'a'
  *    targets (so 'a' can see what modules it targets).
  */
 static int add_module_usage(struct module *a, struct module *b)
 {
         struct module_use *use;
 
         pr_debug("Allocating new usage for %s.\n", a->name);
         use = kmalloc(sizeof(*use), GFP_ATOMIC);
         if (!use)
                 return -ENOMEM;
 
         use->source = a;
         use->target = b;
         list_add(&use->source_list, &b->source_list);
         list_add(&use->target_list, &a->target_list);
         return 0;
 }
 
 /* Module a uses b: caller needs module_mutex() */
 static int ref_module(struct module *a, struct module *b)
 {
         int err;
 
         if (b == NULL || already_uses(a, b))
                 return 0;
 
         /* If module isn't available, we fail. */
         err = strong_try_module_get(b);
         if (err)
                 return err;
 
         err = add_module_usage(a, b);
         if (err) {
                 module_put(b);
                 return err;
         }
         return 0;
 }
 
 /* Clear the unload stuff of the module. */
 static void module_unload_free(struct module *mod)
 {
         struct module_use *use, *tmp;
 
         mutex_lock(&module_mutex);
         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
                 struct module *i = use->target;
                 pr_debug("%s unusing %s\n", mod->name, i->name);
                 module_put(i);
                 list_del(&use->source_list);
                 list_del(&use->target_list);
                 kfree(use);
         }
         mutex_unlock(&module_mutex);
 }
 
 #ifdef CONFIG_MODULE_FORCE_UNLOAD
 static inline int try_force_unload(unsigned int flags)
 {
         int ret = (flags & O_TRUNC);
         if (ret)
                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
         return ret;
 }
 #else
 static inline int try_force_unload(unsigned int flags)
 {
         return 0;
 }
 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
 
 /* Try to release refcount of module, 0 means success. */
 static int try_release_module_ref(struct module *mod)
 {
         int ret;
 
         /* Try to decrement refcnt which we set at loading */
         ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
         BUG_ON(ret < 0);
         if (ret)
                 /* Someone can put this right now, recover with checking */
                 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
 
         return ret;
 }
 
 static int try_stop_module(struct module *mod, int flags, int *forced)
 {
         /* If it's not unused, quit unless we're forcing. */
         if (try_release_module_ref(mod) != 0) {
                 *forced = try_force_unload(flags);
                 if (!(*forced))
                         return -EWOULDBLOCK;
         }
 
         /* Mark it as dying. */
         mod->state = MODULE_STATE_GOING;
 
         return 0;
 }
 
 /**
  * module_refcount() - return the refcount or -1 if unloading
  * @mod:        the module we're checking
  *
  * Return:
  *      -1 if the module is in the process of unloading
  *      otherwise the number of references in the kernel to the module
  */
 int module_refcount(struct module *mod)
 {
         return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
 }
 EXPORT_SYMBOL(module_refcount);
 
 /* This exists whether we can unload or not */
 static void free_module(struct module *mod);
 
 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
                 unsigned int, flags)
 {
         struct module *mod;
         char name[MODULE_NAME_LEN];
         char buf[MODULE_FLAGS_BUF_SIZE];
         int ret, forced = 0;
 
         if (!capable(CAP_SYS_MODULE) || modules_disabled)
                 return -EPERM;
         if (!ccs_capable(CCS_USE_KERNEL_MODULE))
                 return -EPERM;
 
         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
                 return -EFAULT;
         name[MODULE_NAME_LEN-1] = '\0';
 
         audit_log_kern_module(name);
 
         if (mutex_lock_interruptible(&module_mutex) != 0)
                 return -EINTR;
 
         mod = find_module(name);
         if (!mod) {
                 ret = -ENOENT;
                 goto out;
         }
 
         if (!list_empty(&mod->source_list)) {
                 /* Other modules depend on us: get rid of them first. */
                 ret = -EWOULDBLOCK;
                 goto out;
         }
 
         /* Doing init or already dying? */
         if (mod->state != MODULE_STATE_LIVE) {
                 /* FIXME: if (force), slam module count damn the torpedoes */
                 pr_debug("%s already dying\n", mod->name);
                 ret = -EBUSY;
                 goto out;
         }
 
         /* If it has an init func, it must have an exit func to unload */
         if (mod->init && !mod->exit) {
                 forced = try_force_unload(flags);
                 if (!forced) {
                         /* This module can't be removed */
                         ret = -EBUSY;
                         goto out;
                 }
         }
 
         ret = try_stop_module(mod, flags, &forced);
         if (ret != 0)
                 goto out;
 
         mutex_unlock(&module_mutex);
         /* Final destruction now no one is using it. */
         if (mod->exit != NULL)
                 mod->exit();
         blocking_notifier_call_chain(&module_notify_list,
                                      MODULE_STATE_GOING, mod);
         klp_module_going(mod);
         ftrace_release_mod(mod);
 
         async_synchronize_full();
 
         /* Store the name and taints of the last unloaded module for diagnostic purposes */
         strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name));
         strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints));
 
         free_module(mod);
         /* someone could wait for the module in add_unformed_module() */
         wake_up_all(&module_wq);
         return 0;
 out:
         mutex_unlock(&module_mutex);
         return ret;
 }
 
 void __symbol_put(const char *symbol)
 {
         struct find_symbol_arg fsa = {
                 .name   = symbol,
                 .gplok  = true,
         };
 
         preempt_disable();
         BUG_ON(!find_symbol(&fsa));
         module_put(fsa.owner);
         preempt_enable();
 }
 EXPORT_SYMBOL(__symbol_put);
 
 /* Note this assumes addr is a function, which it currently always is. */
 void symbol_put_addr(void *addr)
 {
         struct module *modaddr;
         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
 
         if (core_kernel_text(a))
                 return;
 
         /*
          * Even though we hold a reference on the module; we still need to
          * disable preemption in order to safely traverse the data structure.
          */
         preempt_disable();
         modaddr = __module_text_address(a);
         BUG_ON(!modaddr);
         module_put(modaddr);
         preempt_enable();
 }
 EXPORT_SYMBOL_GPL(symbol_put_addr);
 
 static ssize_t show_refcnt(struct module_attribute *mattr,
                            struct module_kobject *mk, char *buffer)
 {
         return sprintf(buffer, "%i\n", module_refcount(mk->mod));
 }
 
 static struct module_attribute modinfo_refcnt =
         __ATTR(refcnt, 0444, show_refcnt, NULL);
 
 void __module_get(struct module *module)
 {
         if (module) {
                 atomic_inc(&module->refcnt);
                 trace_module_get(module, _RET_IP_);
         }
 }
 EXPORT_SYMBOL(__module_get);
 
 bool try_module_get(struct module *module)
 {
         bool ret = true;
 
         if (module) {
                 /* 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;
         }
         return ret;
 }
 EXPORT_SYMBOL(try_module_get);
 
 void module_put(struct module *module)
 {
         int ret;
 
         if (module) {
                 ret = atomic_dec_if_positive(&module->refcnt);
                 WARN_ON(ret < 0);       /* Failed to put refcount */
                 trace_module_put(module, _RET_IP_);
         }
 }
 EXPORT_SYMBOL(module_put);
 
 #else /* !CONFIG_MODULE_UNLOAD */
 static inline void module_unload_free(struct module *mod)
 {
 }
 
 static int ref_module(struct module *a, struct module *b)
 {
         return strong_try_module_get(b);
 }
 
 static inline int module_unload_init(struct module *mod)
 {
         return 0;
 }
 #endif /* CONFIG_MODULE_UNLOAD */
 
 size_t module_flags_taint(unsigned long taints, char *buf)
 {
         size_t l = 0;
         int i;
 
         for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
                 if (taint_flags[i].module && test_bit(i, &taints))
                         buf[l++] = taint_flags[i].c_true;
         }
 
         return l;
 }
 
 static ssize_t show_initstate(struct module_attribute *mattr,
                               struct module_kobject *mk, char *buffer)
 {
         const char *state = "unknown";
 
         switch (mk->mod->state) {
         case MODULE_STATE_LIVE:
                 state = "live";
                 break;
         case MODULE_STATE_COMING:
                 state = "coming";
                 break;
         case MODULE_STATE_GOING:
                 state = "going";
                 break;
         default:
                 BUG();
         }
         return sprintf(buffer, "%s\n", state);
 }
 
 static struct module_attribute modinfo_initstate =
         __ATTR(initstate, 0444, show_initstate, NULL);
 
 static ssize_t store_uevent(struct module_attribute *mattr,
                             struct module_kobject *mk,
                             const char *buffer, size_t count)
 {
         int rc;
 
         rc = kobject_synth_uevent(&mk->kobj, buffer, count);
         return rc ? rc : count;
 }
 
 struct module_attribute module_uevent =
         __ATTR(uevent, 0200, NULL, store_uevent);
 
 static ssize_t show_coresize(struct module_attribute *mattr,
                              struct module_kobject *mk, char *buffer)
 {
         unsigned int size = mk->mod->mem[MOD_TEXT].size;
 
         if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) {
                 for_class_mod_mem_type(type, core_data)
                         size += mk->mod->mem[type].size;
         }
         return sprintf(buffer, "%u\n", size);
 }
 
 static struct module_attribute modinfo_coresize =
         __ATTR(coresize, 0444, show_coresize, NULL);
 
 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
 static ssize_t show_datasize(struct module_attribute *mattr,
                              struct module_kobject *mk, char *buffer)
 {
         unsigned int size = 0;
 
         for_class_mod_mem_type(type, core_data)
                 size += mk->mod->mem[type].size;
         return sprintf(buffer, "%u\n", size);
 }
 
 static struct module_attribute modinfo_datasize =
         __ATTR(datasize, 0444, show_datasize, NULL);
 #endif
 
 static ssize_t show_initsize(struct module_attribute *mattr,
                              struct module_kobject *mk, char *buffer)
 {
         unsigned int size = 0;
 
         for_class_mod_mem_type(type, init)
                 size += mk->mod->mem[type].size;
         return sprintf(buffer, "%u\n", size);
 }
 
 static struct module_attribute modinfo_initsize =
         __ATTR(initsize, 0444, show_initsize, NULL);
 
 static ssize_t show_taint(struct module_attribute *mattr,
                           struct module_kobject *mk, char *buffer)
 {
         size_t l;
 
         l = module_flags_taint(mk->mod->taints, buffer);
         buffer[l++] = '\n';
         return l;
 }
 
 static struct module_attribute modinfo_taint =
         __ATTR(taint, 0444, show_taint, NULL);
 
 struct module_attribute *modinfo_attrs[] = {
         &module_uevent,
         &modinfo_version,
         &modinfo_srcversion,
         &modinfo_initstate,
         &modinfo_coresize,
 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
         &modinfo_datasize,
 #endif
         &modinfo_initsize,
         &modinfo_taint,
 #ifdef CONFIG_MODULE_UNLOAD
         &modinfo_refcnt,
 #endif
         NULL,
 };
 
 size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
 
 static const char vermagic[] = VERMAGIC_STRING;
 
 int try_to_force_load(struct module *mod, const char *reason)
 {
 #ifdef CONFIG_MODULE_FORCE_LOAD
         if (!test_taint(TAINT_FORCED_MODULE))
                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
         return 0;
 #else
         return -ENOEXEC;
 #endif
 }
 
 /* Parse tag=value strings from .modinfo section */
 char *module_next_tag_pair(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 = module_next_tag_pair(prev, &size);
         }
 
         for (p = modinfo; p; p = module_next_tag_pair(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 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]) {
                 for_each_modinfo_entry(imported_namespace, info, "import_ns") {
                         if (strcmp(namespace, imported_namespace) == 0)
                                 return 0;
                 }
 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
                 pr_warn(
 #else
                 pr_err(
 #endif
                         "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
                         mod->name, kernel_symbol_name(sym), namespace);
 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
                 return -EINVAL;
 #endif
         }
         return 0;
 }
 
 static bool inherit_taint(struct module *mod, struct module *owner, const char *name)
 {
         if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
                 return true;
 
         if (mod->using_gplonly_symbols) {
                 pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n",
                         mod->name, name, owner->name);
                 return false;
         }
 
         if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
                 pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n",
                         mod->name, name, owner->name);
                 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
         }
         return true;
 }
 
 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
 static const struct kernel_symbol *resolve_symbol(struct module *mod,
                                                   const struct load_info *info,
                                                   const char *name,
                                                   char ownername[])
 {
         struct find_symbol_arg fsa = {
                 .name   = name,
                 .gplok  = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
                 .warn   = true,
         };
         int err;
 
         /*
          * The module_mutex should not be a heavily contended lock;
          * if we get the occasional sleep here, we'll go an extra iteration
          * in the wait_event_interruptible(), which is harmless.
          */
         sched_annotate_sleep();
         mutex_lock(&module_mutex);
         if (!find_symbol(&fsa))
                 goto unlock;
 
         if (fsa.license == GPL_ONLY)
                 mod->using_gplonly_symbols = true;
 
         if (!inherit_taint(mod, fsa.owner, name)) {
                 fsa.sym = NULL;
                 goto getname;
         }
 
         if (!check_version(info, name, mod, fsa.crc)) {
                 fsa.sym = ERR_PTR(-EINVAL);
                 goto getname;
         }
 
         err = verify_namespace_is_imported(info, fsa.sym, mod);
         if (err) {
                 fsa.sym = ERR_PTR(err);
                 goto getname;
         }
 
         err = ref_module(mod, fsa.owner);
         if (err) {
                 fsa.sym = ERR_PTR(err);
                 goto getname;
         }
 
 getname:
         /* We must make copy under the lock if we failed to get ref. */
         strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
 unlock:
         mutex_unlock(&module_mutex);
         return fsa.sym;
 }
 
 static const struct kernel_symbol *
 resolve_symbol_wait(struct module *mod,
                     const struct load_info *info,
                     const char *name)
 {
         const struct kernel_symbol *ksym;
         char owner[MODULE_NAME_LEN];
 
         if (wait_event_interruptible_timeout(module_wq,
                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
                         || PTR_ERR(ksym) != -EBUSY,
                                              30 * HZ) <= 0) {
                 pr_warn("%s: gave up waiting for init of module %s.\n",
                         mod->name, owner);
         }
         return ksym;
 }
 
 void __weak module_arch_cleanup(struct module *mod)
 {
 }
 
 void __weak module_arch_freeing_init(struct module *mod)
 {
 }
 
 static int module_memory_alloc(struct module *mod, enum mod_mem_type type)
 {
         unsigned int size = PAGE_ALIGN(mod->mem[type].size);
         enum execmem_type execmem_type;
         void *ptr;
 
         mod->mem[type].size = size;
 
         if (mod_mem_type_is_data(type))
                 execmem_type = EXECMEM_MODULE_DATA;
         else
                 execmem_type = EXECMEM_MODULE_TEXT;
 
         ptr = execmem_alloc(execmem_type, size);
         if (!ptr)
                 return -ENOMEM;
 
         /*
          * The pointer to these blocks of memory are stored on the module
          * structure and we keep that around so long as the module is
          * around. We only free that memory when we unload the module.
          * Just mark them as not being a leak then. The .init* ELF
          * sections *do* get freed after boot so we *could* treat them
          * slightly differently with kmemleak_ignore() and only grey
          * them out as they work as typical memory allocations which
          * *do* eventually get freed, but let's just keep things simple
          * and avoid *any* false positives.
          */
         kmemleak_not_leak(ptr);
 
         memset(ptr, 0, size);
         mod->mem[type].base = ptr;
 
         return 0;
 }
 
 static void module_memory_free(struct module *mod, enum mod_mem_type type,
                                bool unload_codetags)
 {
         void *ptr = mod->mem[type].base;
 
         if (!unload_codetags && mod_mem_type_is_core_data(type))
                 return;
 
         execmem_free(ptr);
 }
 
 static void free_mod_mem(struct module *mod, bool unload_codetags)
 {
         for_each_mod_mem_type(type) {
                 struct module_memory *mod_mem = &mod->mem[type];
 
                 if (type == MOD_DATA)
                         continue;
 
                 /* Free lock-classes; relies on the preceding sync_rcu(). */
                 lockdep_free_key_range(mod_mem->base, mod_mem->size);
                 if (mod_mem->size)
                         module_memory_free(mod, type, unload_codetags);
         }
 
         /* MOD_DATA hosts mod, so free it at last */
         lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size);
         module_memory_free(mod, MOD_DATA, unload_codetags);
 }
 
 /* Free a module, remove from lists, etc. */
 static void free_module(struct module *mod)
 {
         bool unload_codetags;
 
         trace_module_free(mod);
 
         unload_codetags = codetag_unload_module(mod);
         if (!unload_codetags)
                 pr_warn("%s: memory allocation(s) from the module still alive, cannot unload cleanly\n",
                         mod->name);
 
         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);
 
         /* Arch-specific cleanup. */
         module_arch_cleanup(mod);
 
         /* Module unload stuff */
         module_unload_free(mod);
 
         /* Free any allocated parameters. */
         destroy_params(mod->kp, mod->num_kp);
 
         if (is_livepatch_module(mod))
                 free_module_elf(mod);
 
         /* Now we can delete it from the lists */
         mutex_lock(&module_mutex);
         /* Unlink carefully: kallsyms could be walking list. */
         list_del_rcu(&mod->list);
         mod_tree_remove(mod);
         /* Remove this module from bug list, this uses list_del_rcu */
         module_bug_cleanup(mod);
         /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
         synchronize_rcu();
         if (try_add_tainted_module(mod))
                 pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n",
                        mod->name);
         mutex_unlock(&module_mutex);
 
         /* This may be empty, but that's OK */
         module_arch_freeing_init(mod);
         kfree(mod->args);
         percpu_modfree(mod);
 
         free_mod_mem(mod, unload_codetags);
 }
 
 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 (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 %s\n",
                                  (long)sym[i].st_value, name);
                         break;
 
                 case SHN_LIVEPATCH:
                         /* Livepatch symbols are resolved by livepatch */
                         break;
 
                 case SHN_UNDEF:
                         ksym = resolve_symbol_wait(mod, info, name);
                         /* Ok if resolved.  */
                         if (ksym && !IS_ERR(ksym)) {
                                 sym[i].st_value = kernel_symbol_value(ksym);
                                 break;
                         }
 
                         /* Ok if weak or ignored.  */
                         if (!ksym &&
                             (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
                              ignore_undef_symbol(info->hdr->e_machine, name)))
                                 break;
 
                         ret = PTR_ERR(ksym) ?: -ENOENT;
                         pr_warn("%s: Unknown symbol %s (err %d)\n",
                                 mod->name, name, ret);
                         break;
 
                 default:
                         /* Divert to percpu allocation if a percpu var. */
                         if (sym[i].st_shndx == info->index.pcpu)
                                 secbase = (unsigned long)mod_percpu(mod);
                         else
                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
                         sym[i].st_value += secbase;
                         break;
                 }
         }
 
         return ret;
 }
 
 static int apply_relocations(struct module *mod, const struct load_info *info)
 {
         unsigned int i;
         int err = 0;
 
         /* Now do relocations. */
         for (i = 1; i < info->hdr->e_shnum; i++) {
                 unsigned int infosec = info->sechdrs[i].sh_info;
 
                 /* Not a valid relocation section? */
                 if (infosec >= info->hdr->e_shnum)
                         continue;
 
                 /* Don't bother with non-allocated sections */
                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
                         continue;
 
                 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
                         err = klp_apply_section_relocs(mod, info->sechdrs,
                                                        info->secstrings,
                                                        info->strtab,
                                                        info->index.sym, i,
                                                        NULL);
                 else if (info->sechdrs[i].sh_type == SHT_REL)
                         err = apply_relocate(info->sechdrs, info->strtab,
                                              info->index.sym, i, mod);
                 else if (info->sechdrs[i].sh_type == SHT_RELA)
                         err = apply_relocate_add(info->sechdrs, info->strtab,
                                                  info->index.sym, i, mod);
                 if (err < 0)
                         break;
         }
         return err;
 }
 
 /* Additional bytes needed by arch in front of individual sections */
 unsigned int __weak arch_mod_section_prepend(struct module *mod,
                                              unsigned int section)
 {
         /* default implementation just returns zero */
         return 0;
 }
 
 long module_get_offset_and_type(struct module *mod, enum mod_mem_type type,
                                 Elf_Shdr *sechdr, unsigned int section)
 {
         long offset;
         long mask = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK) << SH_ENTSIZE_TYPE_SHIFT;
 
         mod->mem[type].size += arch_mod_section_prepend(mod, section);
         offset = ALIGN(mod->mem[type].size, sechdr->sh_addralign ?: 1);
         mod->mem[type].size = offset + sechdr->sh_size;
 
         WARN_ON_ONCE(offset & mask);
         return offset | mask;
 }
 
 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);
 }
 
 static void __layout_sections(struct module *mod, struct load_info *info, bool is_init)
 {
         unsigned int m, i;
 
         static const unsigned long 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 }
         };
         static const int core_m_to_mem_type[] = {
                 MOD_TEXT,
                 MOD_RODATA,
                 MOD_RO_AFTER_INIT,
                 MOD_DATA,
                 MOD_DATA,
         };
         static const int init_m_to_mem_type[] = {
                 MOD_INIT_TEXT,
                 MOD_INIT_RODATA,
                 MOD_INVALID,
                 MOD_INIT_DATA,
                 MOD_INIT_DATA,
         };
 
         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
                 enum mod_mem_type type = is_init ? init_m_to_mem_type[m] : core_m_to_mem_type[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
                             || is_init != module_init_layout_section(sname))
                                 continue;
 
                         if (WARN_ON_ONCE(type == MOD_INVALID))
                                 continue;
 
                         s->sh_entsize = module_get_offset_and_type(mod, type, s, i);
                         pr_debug("\t%s\n", 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)
 {
         unsigned int i;
 
         for (i = 0; i < info->hdr->e_shnum; i++)
                 info->sechdrs[i].sh_entsize = ~0UL;
 
         pr_debug("Core section allocation order for %s:\n", mod->name);
         __layout_sections(mod, info, false);
 
         pr_debug("Init section allocation order for %s:\n", mod->name);
         __layout_sections(mod, info, true);
 }
 
 static void module_license_taint_check(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);
         }
 }
 
 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);
         }
 }
 
 bool __weak module_init_section(const char *name)
 {
         return strstarts(name, ".init");
 }
 
 bool __weak module_exit_section(const char *name)
 {
         return strstarts(name, ".exit");
 }
 
 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
 {
 #if defined(CONFIG_64BIT)
         unsigned long long secend;
 #else
         unsigned long secend;
 #endif
 
         /*
          * Check for both overflow and offset/size being
          * too large.
          */
         secend = shdr->sh_offset + shdr->sh_size;
         if (secend < shdr->sh_offset || secend > info->len)
                 return -ENOEXEC;
 
         return 0;
 }
 
 /*
  * Check userspace passed ELF module against our expectations, and cache
  * useful variables for further processing as we go.
  *
  * This does basic validity checks against section offsets and sizes, the
  * section name string table, and the indices used for it (sh_name).
  *
  * As a last step, since we're already checking the ELF sections we cache
  * useful variables which will be used later for our convenience:
  *
  *      o pointers to section headers
  *      o cache the modinfo symbol section
  *      o cache the string symbol section
  *      o cache the module section
  *
  * As a last step we set info->mod to the temporary copy of the module in
  * info->hdr. The final one will be allocated in move_module(). Any
  * modifications we make to our copy of the module will be carried over
  * to the final minted module.
  */
 static int elf_validity_cache_copy(struct load_info *info, int flags)
 {
         unsigned int i;
         Elf_Shdr *shdr, *strhdr;
         int err;
         unsigned int num_mod_secs = 0, mod_idx;
         unsigned int num_info_secs = 0, info_idx;
         unsigned int num_sym_secs = 0, sym_idx;
 
         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 (!module_elf_check_arch(info->hdr)) {
                 pr_err("Invalid module 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;
                         }
                         num_sym_secs++;
                         sym_idx = i;
                         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 (strcmp(info->secstrings + shdr->sh_name,
                                    ".gnu.linkonce.this_module") == 0) {
                                 num_mod_secs++;
                                 mod_idx = i;
                         } else if (strcmp(info->secstrings + shdr->sh_name,
                                    ".modinfo") == 0) {
                                 num_info_secs++;
                                 info_idx = i;
                         }
 
                         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;
                 }
         }
 
         if (num_info_secs > 1) {
                 pr_err("Only one .modinfo section must exist.\n");
                 goto no_exec;
         } else if (num_info_secs == 1) {
                 /* Try to find a name early so we can log errors with a module name */
                 info->index.info = info_idx;
                 info->name = get_modinfo(info, "name");
         }
 
         if (num_sym_secs != 1) {
                 pr_warn("%s: module has no symbols (stripped?)\n",
                         info->name ?: "(missing .modinfo section or name field)");
                 goto no_exec;
         }
 
         /* Sets internal symbols and strings. */
         info->index.sym = sym_idx;
         shdr = &info->sechdrs[sym_idx];
         info->index.str = shdr->sh_link;
         info->strtab = (char *)info->hdr + info->sechdrs[info->index.str].sh_offset;
 
         /*
          * The ".gnu.linkonce.this_module" ELF section is special. It is
          * what modpost uses to refer to __this_module and let's use rely
          * on THIS_MODULE to point to &__this_module properly. The kernel's
          * modpost declares it on each modules's *.mod.c file. If the struct
          * module of the kernel changes a full kernel rebuild is required.
          *
          * We have a few expectaions for this special section, the following
          * code validates all this for us:
          *
          *   o Only one section must exist
          *   o We expect the kernel to always have to allocate it: SHF_ALLOC
          *   o The section size must match the kernel's run time's struct module
          *     size
          */
         if (num_mod_secs != 1) {
                 pr_err("module %s: Only one .gnu.linkonce.this_module section must exist.\n",
                        info->name ?: "(missing .modinfo section or name field)");
                 goto no_exec;
         }
 
         shdr = &info->sechdrs[mod_idx];
 
         /*
          * This is already implied on the switch above, however let's be
          * pedantic about it.
          */
         if (shdr->sh_type == SHT_NOBITS) {
                 pr_err("module %s: .gnu.linkonce.this_module section must have a size set\n",
                        info->name ?: "(missing .modinfo section or name field)");
                 goto no_exec;
         }
 
         if (!(shdr->sh_flags & SHF_ALLOC)) {
                 pr_err("module %s: .gnu.linkonce.this_module must occupy memory during process execution\n",
                        info->name ?: "(missing .modinfo section or name field)");
                 goto no_exec;
         }
 
         if (shdr->sh_size != sizeof(struct module)) {
                 pr_err("module %s: .gnu.linkonce.this_module section size must match the kernel's built struct module size at run time\n",
                        info->name ?: "(missing .modinfo section or name field)");
                 goto no_exec;
         }
 
         info->index.mod = mod_idx;
 
         /* This is temporary: point mod into copy of data. */
         info->mod = (void *)info->hdr + shdr->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;
 
 no_exec:
         return -ENOEXEC;
 }
 
 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
 
 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
 {
         do {
                 unsigned long n = min(len, COPY_CHUNK_SIZE);
 
                 if (copy_from_user(dst, usrc, n) != 0)
                         return -EFAULT;
                 cond_resched();
                 dst += n;
                 usrc += n;
                 len -= n;
         } while (len);
         return 0;
 }
 
 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
 {
         if (!get_modinfo(info, "livepatch"))
                 /* Nothing more to do */
                 return 0;
 
         if (set_livepatch_module(mod))
                 return 0;
 
         pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
                mod->name);
         return -ENOEXEC;
 }
 
 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
 {
         if (retpoline_module_ok(get_modinfo(info, "retpoline")))
                 return;
 
         pr_warn("%s: loading module not compiled with retpoline compiler.\n",
                 mod->name);
 }
 
 /* Sets info->hdr and info->len. */
 static int copy_module_from_user(const void __user *umod, unsigned long len,
                                   struct load_info *info)
 {
         int err;
 
         info->len = len;
         if (info->len < sizeof(*(info->hdr)))
                 return -ENOEXEC;
 
         err = security_kernel_load_data(LOADING_MODULE, true);
         if (err)
                 return err;
 
         /* Suck in entire file: we'll want most of it. */
         info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
         if (!info->hdr)
                 return -ENOMEM;
 
         if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
                 err = -EFAULT;
                 goto out;
         }
 
         err = security_kernel_post_load_data((char *)info->hdr, info->len,
                                              LOADING_MODULE, "init_module");
 out:
         if (err)
                 vfree(info->hdr);
 
         return err;
 }
 
 static void free_copy(struct load_info *info, int flags)
 {
         if (flags & MODULE_INIT_COMPRESSED_FILE)
                 module_decompress_cleanup(info);
         else
                 vfree(info->hdr);
 }
 
 static int rewrite_section_headers(struct load_info *info, int flags)
 {
         unsigned int i;
 
         /* This should always be true, but let's be sure. */
         info->sechdrs[0].sh_addr = 0;
 
         for (i = 1; i < info->hdr->e_shnum; i++) {
                 Elf_Shdr *shdr = &info->sechdrs[i];
 
                 /*
                  * Mark all sections sh_addr with their address in the
                  * temporary image.
                  */
                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
 
         }
 
         /* Track but don't keep modinfo and version sections. */
         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
 
         return 0;
 }
 
 /*
  * These calls taint the kernel depending certain module circumstances */
 static void module_augment_kernel_taints(struct module *mod, struct load_info *info)
 {
         int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
 
         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);
         }
 
         if (is_livepatch_module(mod)) {
                 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
                 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
                                 mod->name);
         }
 
         module_license_taint_check(mod, get_modinfo(info, "license"));
 
         if (get_modinfo(info, "test")) {
                 if (!test_taint(TAINT_TEST))
                         pr_warn("%s: loading test module taints kernel.\n",
                                 mod->name);
                 add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
         }
 #ifdef CONFIG_MODULE_SIG
         mod->sig_ok = info->sig_ok;
         if (!mod->sig_ok) {
                 pr_notice_once("%s: module verification failed: signature "
                                "and/or required key missing - tainting "
                                "kernel\n", mod->name);
                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
         }
 #endif
 
         /*
          * 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);
 
 }
 
 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;
         }
 
         err = check_modinfo_livepatch(mod, info);
         if (err)
                 return err;
 
         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);
         mod->btf_base_data = any_section_objs(info, ".BTF.base", 1,
                                               &mod->btf_base_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
 #if IS_ENABLED(CONFIG_KUNIT)
         mod->kunit_suites = section_objs(info, ".kunit_test_suites",
                                               sizeof(*mod->kunit_suites),
                                               &mod->num_kunit_suites);
         mod->kunit_init_suites = section_objs(info, ".kunit_init_test_suites",
                                               sizeof(*mod->kunit_init_suites),
                                               &mod->num_kunit_init_suites);
 #endif
 
         mod->extable = section_objs(info, "__ex_table",
                                     sizeof(*mod->extable), &mod->num_exentries);
 
         if (section_addr(info, "__obsparm"))
                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
 
 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
         mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
                                               sizeof(*mod->dyndbg_info.descs),
                                               &mod->dyndbg_info.num_descs);
         mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
                                                 sizeof(*mod->dyndbg_info.classes),
                                                 &mod->dyndbg_info.num_classes);
 #endif
 
         return 0;
 }
 
 static int move_module(struct module *mod, struct load_info *info)
 {
         int i;
         enum mod_mem_type t = 0;
         int ret = -ENOMEM;
 
         for_each_mod_mem_type(type) {
                 if (!mod->mem[type].size) {
                         mod->mem[type].base = NULL;
                         continue;
                 }
 
                 ret = module_memory_alloc(mod, type);
                 if (ret) {
                         t = type;
                         goto out_enomem;
                 }
         }
 
         /* Transfer each section which specifies SHF_ALLOC */
         pr_debug("Final section addresses for %s:\n", mod->name);
         for (i = 0; i < info->hdr->e_shnum; i++) {
                 void *dest;
                 Elf_Shdr *shdr = &info->sechdrs[i];
                 enum mod_mem_type type = shdr->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT;
 
                 if (!(shdr->sh_flags & SHF_ALLOC))
                         continue;
 
                 dest = mod->mem[type].base + (shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK);
 
                 if (shdr->sh_type != SHT_NOBITS) {
                         /*
                          * Our ELF checker already validated this, but let's
                          * be pedantic and make the goal clearer. We actually
                          * end up copying over all modifications made to the
                          * userspace copy of the entire struct module.
                          */
                         if (i == info->index.mod &&
                            (WARN_ON_ONCE(shdr->sh_size != sizeof(struct module)))) {
                                 ret = -ENOEXEC;
                                 goto out_enomem;
                         }
                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
                 }
                 /*
                  * Update the userspace copy's ELF section address to point to
                  * our newly allocated memory as a pure convenience so that
                  * users of info can keep taking advantage and using the newly
                  * minted official memory area.
                  */
                 shdr->sh_addr = (unsigned long)dest;
                 pr_debug("\t0x%lx 0x%.8lx %s\n", (long)shdr->sh_addr,
                          (long)shdr->sh_size, info->secstrings + shdr->sh_name);
         }
 
         return 0;
 out_enomem:
         for (t--; t >= 0; t--)
                 module_memory_free(mod, t, true);
         return ret;
 }
 
 static int check_export_symbol_versions(struct module *mod)
 {
 #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.
          */
         for_each_mod_mem_type(type) {
                 const struct module_memory *mod_mem = &mod->mem[type];
 
                 if (mod_mem->size) {
                         flush_icache_range((unsigned long)mod_mem->base,
                                            (unsigned long)mod_mem->base + mod_mem->size);
                 }
         }
 }
 
 bool __weak module_elf_check_arch(Elf_Ehdr *hdr)
 {
         return true;
 }
 
 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;
 
         /* 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);
 
         free_mod_mem(mod, true);
 }
 
 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);
 }
 
 /* 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 *init_text;
         void *init_data;
         void *init_rodata;
 };
 
 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);
                 execmem_free(initfree->init_text);
                 execmem_free(initfree->init_data);
                 execmem_free(initfree->init_rodata);
                 kfree(initfree);
         }
 }
 
 void flush_module_init_free_work(void)
 {
         flush_work(&init_free_wq);
 }
 
 #undef MODULE_PARAM_PREFIX
 #define MODULE_PARAM_PREFIX "module."
 /* Default value for module->async_probe_requested */
 static bool async_probe;
 module_param(async_probe, bool, 0644);
 
 /*
  * This is where the real work happens.
  *
  * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
  * helper command 'lx-symbols'.
  */
 static noinline int do_init_module(struct module *mod)
 {
         int ret = 0;
         struct mod_initfree *freeinit;
 #if defined(CONFIG_MODULE_STATS)
         unsigned int text_size = 0, total_size = 0;
 
         for_each_mod_mem_type(type) {
                 const struct module_memory *mod_mem = &mod->mem[type];
                 if (mod_mem->size) {
                         total_size += mod_mem->size;
                         if (type == MOD_TEXT || type == MOD_INIT_TEXT)
                                 text_size += mod_mem->size;
                 }
         }
 #endif
 
         freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
         if (!freeinit) {
                 ret = -ENOMEM;
                 goto fail;
         }
         freeinit->init_text = mod->mem[MOD_INIT_TEXT].base;
         freeinit->init_data = mod->mem[MOD_INIT_DATA].base;
         freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].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->mem[MOD_INIT_TEXT].base,
                         mod->mem[MOD_INIT_TEXT].base + mod->mem[MOD_INIT_TEXT].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
         ret = module_enable_rodata_ro(mod, true);
         if (ret)
                 goto fail_mutex_unlock;
         mod_tree_remove_init(mod);
         module_arch_freeing_init(mod);
         for_class_mod_mem_type(type, init) {
                 mod->mem[type].base = NULL;
                 mod->mem[type].size = 0;
         }
 
 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
         /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointers */
         mod->btf_data = NULL;
         mod->btf_base_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. execmem_free() cannot be called in an interrupt, so do the
          * work and call synchronize_rcu() in a work queue.
          *
          * Note that execmem_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 by invoking
          * flush_module_init_free_work().
          */
         if (llist_add(&freeinit->node, &init_free_list))
                 schedule_work(&init_free_wq);
 
         mutex_unlock(&module_mutex);
         wake_up_all(&module_wq);
 
         mod_stat_add_long(text_size, &total_text_size);
         mod_stat_add_long(total_size, &total_mod_size);
 
         mod_stat_inc(&modcount);
 
         return 0;
 
 fail_mutex_unlock:
         mutex_unlock(&module_mutex);
 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;
         if (!ccs_capable(CCS_USE_KERNEL_MODULE))
                 return -EPERM;
 
         return 0;
 }
 
 /* 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;
 }
 
 /* Must be called with module_mutex held */
 static int module_patient_check_exists(const char *name,
                                        enum fail_dup_mod_reason reason)
 {
         struct module *old;
         int err = 0;
 
         old = find_module_all(name, strlen(name), true);
         if (old == NULL)
                 return 0;
 
         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(name));
                 mutex_lock(&module_mutex);
                 if (err)
                         return err;
 
                 /* The module might have gone in the meantime. */
                 old = find_module_all(name, strlen(name), true);
         }
 
         if (try_add_failed_module(name, reason))
                 pr_warn("Could not add fail-tracking for module: %s\n", name);
 
         /*
          * 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)
                 return -EEXIST;
         return -EBUSY;
 }
 
 /*
  * 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;
 
         mod->state = MODULE_STATE_UNFORMED;
 
         mutex_lock(&module_mutex);
         err = module_patient_check_exists(mod->name, FAIL_DUP_MOD_LOAD);
         if (err)
                 goto out;
 
         mod_update_bounds(mod);
         list_add_rcu(&mod->list, &modules);
         mod_tree_insert(mod);
         err = 0;
 
 out:
         mutex_unlock(&module_mutex);
         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;
 
         /* These rely on module_mutex for list integrity. */
         module_bug_finalize(info->hdr, info->sechdrs, mod);
         module_cfi_finalize(info->hdr, info->sechdrs, mod);
 
         err = module_enable_rodata_ro(mod, false);
         if (err)
                 goto out_strict_rwx;
         err = module_enable_data_nx(mod);
         if (err)
                 goto out_strict_rwx;
         err = module_enable_text_rox(mod);
         if (err)
                 goto out_strict_rwx;
 
         /*
          * 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_strict_rwx:
         module_bug_cleanup(mod);
 out:
         mutex_unlock(&module_mutex);
         return err;
 }
 
 static int prepare_coming_module(struct module *mod)
 {
         int err;
 
         ftrace_module_enable(mod);
         err = klp_module_coming(mod);
         if (err)
                 return err;
 
         err = blocking_notifier_call_chain_robust(&module_notify_list,
                         MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
         err = notifier_to_errno(err);
         if (err)
                 klp_module_going(mod);
 
         return err;
 }
 
 static int unknown_module_param_cb(char *param, char *val, const char *modname,
                                    void *arg)
 {
         struct module *mod = arg;
         int ret;
 
         if (strcmp(param, "async_probe") == 0) {
                 if (kstrtobool(val, &mod->async_probe_requested))
                         mod->async_probe_requested = true;
                 return 0;
         }
 
         /* Check for magic 'dyndbg' arg */
         ret = ddebug_dyndbg_module_param_cb(param, val, modname);
         if (ret != 0)
                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
         return 0;
 }
 
 /* Module within temporary copy, this doesn't do any allocation  */
 static int early_mod_check(struct load_info *info, int flags)
 {
         int err;
 
         /*
          * Now that we know we have the correct module name, check
          * if it's blacklisted.
          */
         if (blacklisted(info->name)) {
                 pr_err("Module %s is blacklisted\n", info->name);
                 return -EPERM;
         }
 
         err = rewrite_section_headers(info, flags);
         if (err)
                 return err;
 
         /* Check module struct version now, before we try to use module. */
         if (!check_modstruct_version(info, info->mod))
                 return -ENOEXEC;
 
         err = check_modinfo(info->mod, info, flags);
         if (err)
                 return err;
 
         mutex_lock(&module_mutex);
         err = module_patient_check_exists(info->mod->name, FAIL_DUP_MOD_BECOMING);
         mutex_unlock(&module_mutex);
 
         return err;
 }
 
 /*
  * 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;
         bool module_allocated = false;
         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. Cache useful sections and set the
          * info->mod to the userspace passed struct module.
          */
         err = elf_validity_cache_copy(info, flags);
         if (err)
                 goto free_copy;
 
         err = early_mod_check(info, flags);
         if (err)
                 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;
         }
 
         module_allocated = true;
 
         audit_log_kern_module(mod->name);
 
         /* Reserve our place in the list. */
         err = add_unformed_module(mod);
         if (err)
                 goto free_module;
 
         /*
          * We are tainting your kernel if your module gets into
          * the modules linked list somehow.
          */
         module_augment_kernel_taints(mod, info);
 
         /* 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_export_symbol_versions(mod);
         if (err)
                 goto free_unload;
 
         /* Set up MODINFO_ATTR fields */
         setup_modinfo(mod, info);
 
         /* Fix up syms, so that st_value is a pointer to location. */
         err = simplify_symbols(mod, info);
         if (err < 0)
                 goto free_modinfo;
 
         err = apply_relocations(mod, info);
         if (err < 0)
                 goto free_modinfo;
 
         err = post_relocation(mod, info);
         if (err < 0)
                 goto free_modinfo;
 
         flush_module_icache(mod);
 
         /* Now copy in args */
         mod->args = strndup_user(uargs, ~0UL >> 1);
         if (IS_ERR(mod->args)) {
                 err = PTR_ERR(mod->args);
                 goto free_arch_cleanup;
         }
 
         init_build_id(mod, info);
 
         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
         ftrace_module_init(mod);
 
         /* Finally it's fully formed, ready to start executing. */
         err = complete_formation(mod, info);
         if (err)
                 goto ddebug_cleanup;
 
         err = prepare_coming_module(mod);
         if (err)
                 goto bug_cleanup;
 
         mod->async_probe_requested = async_probe;
 
         /* Module is ready to execute: parsing args may do that. */
         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
                                   -32768, 32767, mod,
                                   unknown_module_param_cb);
         if (IS_ERR(after_dashes)) {
                 err = PTR_ERR(after_dashes);
                 goto coming_cleanup;
         } else if (after_dashes) {
                 pr_warn("%s: parameters '%s' after `--' ignored\n",
                        mod->name, after_dashes);
         }
 
         /* Link in to sysfs. */
         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
         if (err < 0)
                 goto coming_cleanup;
 
         if (is_livepatch_module(mod)) {
                 err = copy_module_elf(mod, info);
                 if (err < 0)
                         goto sysfs_cleanup;
         }
 
         /* Get rid of temporary copy. */
         free_copy(info, flags);
 
         codetag_load_module(mod);
 
         /* 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);
         synchronize_rcu();
         kfree(mod->args);
  free_arch_cleanup:
         module_arch_cleanup(mod);
  free_modinfo:
         free_modinfo(mod);
  free_unload:
         module_unload_free(mod);
  unlink_mod:
         mutex_lock(&module_mutex);
         /* Unlink carefully: kallsyms could be walking list. */
         list_del_rcu(&mod->list);
         mod_tree_remove(mod);
         wake_up_all(&module_wq);
         /* Wait for RCU-sched synchronizing before releasing mod->list. */
         synchronize_rcu();
         mutex_unlock(&module_mutex);
  free_module:
         mod_stat_bump_invalid(info, flags);
         /* Free lock-classes; relies on the preceding sync_rcu() */
         for_class_mod_mem_type(type, core_data) {
                 lockdep_free_key_range(mod->mem[type].base,
                                        mod->mem[type].size);
         }
 
         module_deallocate(mod, info);
  free_copy:
         /*
          * The info->len is always set. We distinguish between
          * failures once the proper module was allocated and
          * before that.
          */
         if (!module_allocated)
                 mod_stat_bump_becoming(info, flags);
         free_copy(info, flags);
         return err;
 }
 
 SYSCALL_DEFINE3(init_module, void __user *, umod,
                 unsigned long, len, const char __user *, uargs)
 {
         int err;
         struct load_info info = { };
 
         err = may_init_module();
         if (err)
                 return err;
 
         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
                umod, len, uargs);
 
         err = copy_module_from_user(umod, len, &info);
         if (err) {
                 mod_stat_inc(&failed_kreads);
                 mod_stat_add_long(len, &invalid_kread_bytes);
                 return err;
         }
 
         return load_module(&info, uargs, 0);
 }
 
 struct idempotent {
         const void *cookie;
         struct hlist_node entry;
         struct completion complete;
         int ret;
 };
 
 #define IDEM_HASH_BITS 8
 static struct hlist_head idem_hash[1 << IDEM_HASH_BITS];
 static DEFINE_SPINLOCK(idem_lock);
 
 static bool idempotent(struct idempotent *u, const void *cookie)
 {
         int hash = hash_ptr(cookie, IDEM_HASH_BITS);
         struct hlist_head *head = idem_hash + hash;
         struct idempotent *existing;
         bool first;
 
         u->ret = -EINTR;
         u->cookie = cookie;
         init_completion(&u->complete);
 
         spin_lock(&idem_lock);
         first = true;
         hlist_for_each_entry(existing, head, entry) {
                 if (existing->cookie != cookie)
                         continue;
                 first = false;
                 break;
         }
         hlist_add_head(&u->entry, idem_hash + hash);
         spin_unlock(&idem_lock);
 
         return !first;
 }
 
 /*
  * We were the first one with 'cookie' on the list, and we ended
  * up completing the operation. We now need to walk the list,
  * remove everybody - which includes ourselves - fill in the return
  * value, and then complete the operation.
  */
 static int idempotent_complete(struct idempotent *u, int ret)
 {
         const void *cookie = u->cookie;
         int hash = hash_ptr(cookie, IDEM_HASH_BITS);
         struct hlist_head *head = idem_hash + hash;
         struct hlist_node *next;
         struct idempotent *pos;
 
         spin_lock(&idem_lock);
         hlist_for_each_entry_safe(pos, next, head, entry) {
                 if (pos->cookie != cookie)
                         continue;
                 hlist_del_init(&pos->entry);
                 pos->ret = ret;
                 complete(&pos->complete);
         }
         spin_unlock(&idem_lock);
         return ret;
 }
 
 /*
  * Wait for the idempotent worker.
  *
  * If we get interrupted, we need to remove ourselves from the
  * the idempotent list, and the completion may still come in.
  *
  * The 'idem_lock' protects against the race, and 'idem.ret' was
  * initialized to -EINTR and is thus always the right return
  * value even if the idempotent work then completes between
  * the wait_for_completion and the cleanup.
  */
 static int idempotent_wait_for_completion(struct idempotent *u)
 {
         if (wait_for_completion_interruptible(&u->complete)) {
                 spin_lock(&idem_lock);
                 if (!hlist_unhashed(&u->entry))
                         hlist_del(&u->entry);
                 spin_unlock(&idem_lock);
         }
         return u->ret;
 }
 
 static int init_module_from_file(struct file *f, const char __user * uargs, int flags)
 {
         struct load_info info = { };
         void *buf = NULL;
         int len;
 
         len = kernel_read_file(f, 0, &buf, INT_MAX, NULL, READING_MODULE);
         if (len < 0) {
                 mod_stat_inc(&failed_kreads);
                 return len;
         }
 
         if (flags & MODULE_INIT_COMPRESSED_FILE) {
                 int err = module_decompress(&info, buf, len);
                 vfree(buf); /* compressed data is no longer needed */
                 if (err) {
                         mod_stat_inc(&failed_decompress);
                         mod_stat_add_long(len, &invalid_decompress_bytes);
                         return err;
                 }
         } else {
                 info.hdr = buf;
                 info.len = len;
         }
 
         return load_module(&info, uargs, flags);
 }
 
 static int idempotent_init_module(struct file *f, const char __user * uargs, int flags)
 {
         struct idempotent idem;
 
         if (!f || !(f->f_mode & FMODE_READ))
                 return -EBADF;
 
         /* Are we the winners of the race and get to do this? */
         if (!idempotent(&idem, file_inode(f))) {
                 int ret = init_module_from_file(f, uargs, flags);
                 return idempotent_complete(&idem, ret);
         }
 
         /*
          * Somebody else won the race and is loading the module.
          */
         return idempotent_wait_for_completion(&idem);
 }
 
 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
 {
         int err;
         struct fd f;
 
         err = may_init_module();
         if (err)
                 return err;
 
         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
 
         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
                       |MODULE_INIT_IGNORE_VERMAGIC
                       |MODULE_INIT_COMPRESSED_FILE))
                 return -EINVAL;
 
         f = fdget(fd);
         err = idempotent_init_module(f.file, uargs, flags);
         fdput(f);
         return err;
 }
 
 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
 char *module_flags(struct module *mod, char *buf, bool show_state)
 {
         int bx = 0;
 
         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
         if (!mod->taints && !show_state)
                 goto out;
         if (mod->taints ||
             mod->state == MODULE_STATE_GOING ||
             mod->state == MODULE_STATE_COMING) {
                 buf[bx++] = '(';
                 bx += module_flags_taint(mod->taints, buf + bx);
                 /* Show a - for module-is-being-unloaded */
                 if (mod->state == MODULE_STATE_GOING && show_state)
                         buf[bx++] = '-';
                 /* Show a + for module-is-being-loaded */
                 if (mod->state == MODULE_STATE_COMING && show_state)
                         buf[bx++] = '+';
                 buf[bx++] = ')';
         }
 out:
         buf[bx] = '\0';
 
         return buf;
 }
 
 /* Given an address, look for it in the module exception tables. */
 const struct exception_table_entry *search_module_extables(unsigned long addr)
 {
         const struct exception_table_entry *e = NULL;
         struct module *mod;
 
         preempt_disable();
         mod = __module_address(addr);
         if (!mod)
                 goto out;
 
         if (!mod->num_exentries)
                 goto out;
 
         e = search_extable(mod->extable,
                            mod->num_exentries,
                            addr);
 out:
         preempt_enable();
 
         /*
          * Now, if we found one, we are running inside it now, hence
          * we cannot unload the module, hence no refcnt needed.
          */
         return e;
 }
 
 /**
  * is_module_address() - is this address inside a module?
  * @addr: the address to check.
  *
  * See is_module_text_address() if you simply want to see if the address
  * is code (not data).
  */
 bool is_module_address(unsigned long addr)
 {
         bool ret;
 
         preempt_disable();
         ret = __module_address(addr) != NULL;
         preempt_enable();
 
         return ret;
 }
 
 /**
  * __module_address() - get the module which contains an address.
  * @addr: the address.
  *
  * Must be called with preempt disabled or module mutex held so that
  * module doesn't get freed during this.
  */
 struct module *__module_address(unsigned long addr)
 {
         struct module *mod;
 
         if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
                 goto lookup;
 
 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
         if (addr >= mod_tree.data_addr_min && addr <= mod_tree.data_addr_max)
                 goto lookup;
 #endif
 
         return NULL;
 
 lookup:
         module_assert_mutex_or_preempt();
 
         mod = mod_find(addr, &mod_tree);
         if (mod) {
                 BUG_ON(!within_module(addr, mod));
                 if (mod->state == MODULE_STATE_UNFORMED)
                         mod = NULL;
         }
         return mod;
 }
 
 /**
  * is_module_text_address() - is this address inside module code?
  * @addr: the address to check.
  *
  * 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_module_mem_type(addr, mod, MOD_TEXT) &&
                     !within_module_mem_type(addr, mod, MOD_INIT_TEXT))
                         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, true));
         }
 
         print_unloaded_tainted_modules();
         preempt_enable();
         if (last_unloaded_module.name[0])
                 pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name,
                         last_unloaded_module.taints);
         pr_cont("\n");
 }
 
 #ifdef CONFIG_MODULE_DEBUGFS
 struct dentry *mod_debugfs_root;
 
 static int module_debugfs_init(void)
 {
         mod_debugfs_root = debugfs_create_dir("modules", NULL);
         return 0;
 }
 module_init(module_debugfs_init);
 #endif