/* Rewritten by Rusty Russell, on the backs of many others...
     Copyright (C) 2002 Richard Henderson
     Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
  
      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation; either version 2 of the License, or
      (at your option) any later version.
  
      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU General Public License for more details.
  
      You should have received a copy of the GNU General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
  #include <linux/config.h>
  #include <linux/module.h>
  #include <linux/moduleloader.h>
  #include <linux/init.h>

  #include <linux/kernel.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/stop_machine.h>
  #include <linux/device.h>

  #include <linux/string.h>

  #include <linux/sched.h>

  #include <linux/mutex.h>

  #include <asm/uaccess.h>
  #include <asm/semaphore.h>
  #include <asm/cacheflush.h>
  
  #if 0
  #define DEBUGP printk
  #else
  #define DEBUGP(fmt , a...)
  #endif
  
  #ifndef ARCH_SHF_SMALL
  #define ARCH_SHF_SMALL 0
  #endif
  
  /* If this is set, the section belongs in the init part of the module */
  #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
  
  /* Protects module list */
  static DEFINE_SPINLOCK(modlist_lock);
  
  /* List of modules, protected by module_mutex AND modlist_lock */

  static DEFINE_MUTEX(module_mutex);

  static LIST_HEAD(modules);

  static DEFINE_MUTEX(notify_mutex);

  static struct notifier_block * module_notify_list;
  
  int register_module_notifier(struct notifier_block * nb)
  {
  	int err;

  	mutex_lock(&notify_mutex);

  	err = notifier_chain_register(&module_notify_list, nb);

  	mutex_unlock(&notify_mutex);

  	return err;
  }
  EXPORT_SYMBOL(register_module_notifier);
  
  int unregister_module_notifier(struct notifier_block * nb)
  {
  	int err;

  	mutex_lock(&notify_mutex);

  	err = notifier_chain_unregister(&module_notify_list, nb);

  	mutex_unlock(&notify_mutex);

  	return err;
  }
  EXPORT_SYMBOL(unregister_module_notifier);
  
  /* We require a truly strong try_module_get() */
  static inline int strong_try_module_get(struct module *mod)
  {
  	if (mod && mod->state == MODULE_STATE_COMING)
  		return 0;
  	return try_module_get(mod);
  }
  
  /* A thread that wants to hold a reference to a module only while it
   * is running can call ths to safely exit.
   * nfsd and lockd use this.
   */
  void __module_put_and_exit(struct module *mod, long code)
  {
  	module_put(mod);
  	do_exit(code);
  }
  EXPORT_SYMBOL(__module_put_and_exit);
  	
  /* Find a module section: 0 means not found. */
  static unsigned int find_sec(Elf_Ehdr *hdr,
  			     Elf_Shdr *sechdrs,
  			     const char *secstrings,
  			     const char *name)
  {
  	unsigned int i;
  
  	for (i = 1; i < hdr->e_shnum; i++)
  		/* Alloc bit cleared means "ignore it." */
  		if ((sechdrs[i].sh_flags & SHF_ALLOC)
  		    && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
  			return i;
  	return 0;
  }
  
  /* Provided by the linker */
  extern const struct kernel_symbol __start___ksymtab[];
  extern const struct kernel_symbol __stop___ksymtab[];
  extern const struct kernel_symbol __start___ksymtab_gpl[];
  extern const struct kernel_symbol __stop___ksymtab_gpl[];

  extern const struct kernel_symbol __start___ksymtab_gpl_future[];
  extern const struct kernel_symbol __stop___ksymtab_gpl_future[];

  extern const unsigned long __start___kcrctab[];
  extern const unsigned long __start___kcrctab_gpl[];

  extern const unsigned long __start___kcrctab_gpl_future[];

  
  #ifndef CONFIG_MODVERSIONS
  #define symversion(base, idx) NULL
  #else
  #define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL)
  #endif

  /* lookup symbol in given range of kernel_symbols */
  static const struct kernel_symbol *lookup_symbol(const char *name,
  	const struct kernel_symbol *start,
  	const struct kernel_symbol *stop)
  {
  	const struct kernel_symbol *ks = start;
  	for (; ks < stop; ks++)
  		if (strcmp(ks->name, name) == 0)
  			return ks;
  	return NULL;
  }

  /* Find a symbol, return value, crc and module which owns it */
  static unsigned long __find_symbol(const char *name,
  				   struct module **owner,
  				   const unsigned long **crc,
  				   int gplok)
  {
  	struct module *mod;

  	const struct kernel_symbol *ks;

  
  	/* Core kernel first. */ 
  	*owner = NULL;

  	ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
  	if (ks) {
  		*crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
  		return ks->value;

  	}
  	if (gplok) {

  		ks = lookup_symbol(name, __start___ksymtab_gpl,
  					 __stop___ksymtab_gpl);
  		if (ks) {
  			*crc = symversion(__start___kcrctab_gpl,
  					  (ks - __start___ksymtab_gpl));
  			return ks->value;
  		}

  	}

  	ks = lookup_symbol(name, __start___ksymtab_gpl_future,
  				 __stop___ksymtab_gpl_future);
  	if (ks) {
  		if (!gplok) {
  			printk(KERN_WARNING "Symbol %s is being used "
  			       "by a non-GPL module, which will not "
  			       "be allowed in the future
  ", name);
  			printk(KERN_WARNING "Please see the file "
  			       "Documentation/feature-removal-schedule.txt "
  			       "in the kernel source tree for more "
  			       "details.
  ");
  		}
  		*crc = symversion(__start___kcrctab_gpl_future,
  				  (ks - __start___ksymtab_gpl_future));
  		return ks->value;
  	}

  
  	/* Now try modules. */ 
  	list_for_each_entry(mod, &modules, list) {
  		*owner = mod;

  		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
  		if (ks) {
  			*crc = symversion(mod->crcs, (ks - mod->syms));
  			return ks->value;
  		}

  
  		if (gplok) {

  			ks = lookup_symbol(name, mod->gpl_syms,
  					   mod->gpl_syms + mod->num_gpl_syms);
  			if (ks) {
  				*crc = symversion(mod->gpl_crcs,
  						  (ks - mod->gpl_syms));
  				return ks->value;

  			}
  		}

  		ks = lookup_symbol(name, mod->gpl_future_syms,
  				   (mod->gpl_future_syms +
  				    mod->num_gpl_future_syms));
  		if (ks) {
  			if (!gplok) {
  				printk(KERN_WARNING "Symbol %s is being used "
  				       "by a non-GPL module, which will not "
  				       "be allowed in the future
  ", name);
  				printk(KERN_WARNING "Please see the file "
  				       "Documentation/feature-removal-schedule.txt "
  				       "in the kernel source tree for more "
  				       "details.
  ");
  			}
  			*crc = symversion(mod->gpl_future_crcs,
  					  (ks - mod->gpl_future_syms));
  			return ks->value;
  		}

  	}
  	DEBUGP("Failed to find symbol %s
  ", name);
   	return 0;
  }

  /* Search for module by name: must hold module_mutex. */
  static struct module *find_module(const char *name)
  {
  	struct module *mod;
  
  	list_for_each_entry(mod, &modules, list) {
  		if (strcmp(mod->name, name) == 0)
  			return mod;
  	}
  	return NULL;
  }
  
  #ifdef CONFIG_SMP
  /* Number of blocks used and allocated. */
  static unsigned int pcpu_num_used, pcpu_num_allocated;
  /* Size of each block.  -ve means used. */
  static int *pcpu_size;
  
  static int split_block(unsigned int i, unsigned short size)
  {
  	/* Reallocation required? */
  	if (pcpu_num_used + 1 > pcpu_num_allocated) {
  		int *new = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2,
  				   GFP_KERNEL);
  		if (!new)
  			return 0;
  
  		memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated);
  		pcpu_num_allocated *= 2;
  		kfree(pcpu_size);
  		pcpu_size = new;
  	}
  
  	/* Insert a new subblock */
  	memmove(&pcpu_size[i+1], &pcpu_size[i],
  		sizeof(pcpu_size[0]) * (pcpu_num_used - i));
  	pcpu_num_used++;
  
  	pcpu_size[i+1] -= size;
  	pcpu_size[i] = size;
  	return 1;
  }
  
  static inline unsigned int block_size(int val)
  {
  	if (val < 0)
  		return -val;
  	return val;
  }
  
  /* Created by linker magic */
  extern char __per_cpu_start[], __per_cpu_end[];

  static void *percpu_modalloc(unsigned long size, unsigned long align,
  			     const char *name)

  {
  	unsigned long extra;
  	unsigned int i;
  	void *ptr;

  	if (align > SMP_CACHE_BYTES) {
  		printk(KERN_WARNING "%s: per-cpu alignment %li > %i
  ",
  		       name, align, SMP_CACHE_BYTES);
  		align = SMP_CACHE_BYTES;
  	}

  
  	ptr = __per_cpu_start;
  	for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
  		/* Extra for alignment requirement. */
  		extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
  		BUG_ON(i == 0 && extra != 0);
  
  		if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
  			continue;
  
  		/* Transfer extra to previous block. */
  		if (pcpu_size[i-1] < 0)
  			pcpu_size[i-1] -= extra;
  		else
  			pcpu_size[i-1] += extra;
  		pcpu_size[i] -= extra;
  		ptr += extra;
  
  		/* Split block if warranted */
  		if (pcpu_size[i] - size > sizeof(unsigned long))
  			if (!split_block(i, size))
  				return NULL;
  
  		/* Mark allocated */
  		pcpu_size[i] = -pcpu_size[i];
  		return ptr;
  	}
  
  	printk(KERN_WARNING "Could not allocate %lu bytes percpu data
  ",
  	       size);
  	return NULL;
  }
  
  static void percpu_modfree(void *freeme)
  {
  	unsigned int i;
  	void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
  
  	/* First entry is core kernel percpu data. */
  	for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
  		if (ptr == freeme) {
  			pcpu_size[i] = -pcpu_size[i];
  			goto free;
  		}
  	}
  	BUG();
  
   free:
  	/* Merge with previous? */
  	if (pcpu_size[i-1] >= 0) {
  		pcpu_size[i-1] += pcpu_size[i];
  		pcpu_num_used--;
  		memmove(&pcpu_size[i], &pcpu_size[i+1],
  			(pcpu_num_used - i) * sizeof(pcpu_size[0]));
  		i--;
  	}
  	/* Merge with next? */
  	if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
  		pcpu_size[i] += pcpu_size[i+1];
  		pcpu_num_used--;
  		memmove(&pcpu_size[i+1], &pcpu_size[i+2],
  			(pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
  	}
  }
  
  static unsigned int find_pcpusec(Elf_Ehdr *hdr,
  				 Elf_Shdr *sechdrs,
  				 const char *secstrings)
  {
  	return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
  }
  
  static int percpu_modinit(void)
  {
  	pcpu_num_used = 2;
  	pcpu_num_allocated = 2;
  	pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
  			    GFP_KERNEL);
  	/* Static in-kernel percpu data (used). */
  	pcpu_size[0] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES);
  	/* Free room. */
  	pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
  	if (pcpu_size[1] < 0) {
  		printk(KERN_ERR "No per-cpu room for modules.
  ");
  		pcpu_num_used = 1;
  	}
  
  	return 0;
  }	
  __initcall(percpu_modinit);
  #else /* ... !CONFIG_SMP */

  static inline void *percpu_modalloc(unsigned long size, unsigned long align,
  				    const char *name)

  {
  	return NULL;
  }
  static inline void percpu_modfree(void *pcpuptr)
  {
  	BUG();
  }
  static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
  					Elf_Shdr *sechdrs,
  					const char *secstrings)
  {
  	return 0;
  }
  static inline void percpu_modcopy(void *pcpudst, const void *src,
  				  unsigned long size)
  {
  	/* pcpusec should be 0, and size of that section should be 0. */
  	BUG_ON(size != 0);
  }
  #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 *mod, char *buffer)             \
  {                                                                     \
  	return sprintf(buffer, "%s
  ", 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,           \
  		  .owner = THIS_MODULE },                             \
  	.show = show_modinfo_##field,                                 \
  	.setup = setup_modinfo_##field,                               \
  	.test = modinfo_##field##_exists,                             \
  	.free = free_modinfo_##field,                                 \
  };
  
  MODINFO_ATTR(version);
  MODINFO_ATTR(srcversion);

  #ifdef CONFIG_MODULE_UNLOAD

  /* Init the unload section of the module. */
  static void module_unload_init(struct module *mod)
  {
  	unsigned int i;
  
  	INIT_LIST_HEAD(&mod->modules_which_use_me);
  	for (i = 0; i < NR_CPUS; i++)
  		local_set(&mod->ref[i].count, 0);
  	/* Hold reference count during initialization. */

  	local_set(&mod->ref[raw_smp_processor_id()].count, 1);

  	/* Backwards compatibility macros put refcount during init. */
  	mod->waiter = current;
  }
  
  /* modules using other modules */
  struct module_use
  {
  	struct list_head list;
  	struct module *module_which_uses;
  };
  
  /* 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->modules_which_use_me, list) {
  		if (use->module_which_uses == a) {
  			DEBUGP("%s uses %s!
  ", a->name, b->name);
  			return 1;
  		}
  	}
  	DEBUGP("%s does not use %s!
  ", a->name, b->name);
  	return 0;
  }
  
  /* Module a uses b */
  static int use_module(struct module *a, struct module *b)
  {
  	struct module_use *use;
  	if (b == NULL || already_uses(a, b)) return 1;
  
  	if (!strong_try_module_get(b))
  		return 0;
  
  	DEBUGP("Allocating new usage for %s.
  ", a->name);
  	use = kmalloc(sizeof(*use), GFP_ATOMIC);
  	if (!use) {
  		printk("%s: out of memory loading
  ", a->name);
  		module_put(b);
  		return 0;
  	}
  
  	use->module_which_uses = a;
  	list_add(&use->list, &b->modules_which_use_me);
  	return 1;
  }
  
  /* Clear the unload stuff of the module. */
  static void module_unload_free(struct module *mod)
  {
  	struct module *i;
  
  	list_for_each_entry(i, &modules, list) {
  		struct module_use *use;
  
  		list_for_each_entry(use, &i->modules_which_use_me, list) {
  			if (use->module_which_uses == mod) {
  				DEBUGP("%s unusing %s
  ", mod->name, i->name);
  				module_put(i);
  				list_del(&use->list);
  				kfree(use);
  				/* There can be at most one match. */
  				break;
  			}
  		}
  	}
  }
  
  #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);

  	return ret;
  }
  #else

  static inline int try_force_unload(unsigned int flags)

  {
  	return 0;
  }
  #endif /* CONFIG_MODULE_FORCE_UNLOAD */
  
  struct stopref
  {
  	struct module *mod;
  	int flags;
  	int *forced;
  };
  
  /* Whole machine is stopped with interrupts off when this runs. */
  static int __try_stop_module(void *_sref)
  {
  	struct stopref *sref = _sref;
  
  	/* If it's not unused, quit unless we are told to block. */
  	if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {

  		if (!(*sref->forced = try_force_unload(sref->flags)))

  			return -EWOULDBLOCK;
  	}
  
  	/* Mark it as dying. */
  	sref->mod->state = MODULE_STATE_GOING;
  	return 0;
  }
  
  static int try_stop_module(struct module *mod, int flags, int *forced)
  {
  	struct stopref sref = { mod, flags, forced };
  
  	return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
  }
  
  unsigned int module_refcount(struct module *mod)
  {
  	unsigned int i, total = 0;
  
  	for (i = 0; i < NR_CPUS; i++)
  		total += local_read(&mod->ref[i].count);
  	return total;
  }
  EXPORT_SYMBOL(module_refcount);
  
  /* This exists whether we can unload or not */
  static void free_module(struct module *mod);
  
  static void wait_for_zero_refcount(struct module *mod)
  {
  	/* Since we might sleep for some time, drop the semaphore first */

  	mutex_unlock(&module_mutex);

  	for (;;) {
  		DEBUGP("Looking at refcount...
  ");
  		set_current_state(TASK_UNINTERRUPTIBLE);
  		if (module_refcount(mod) == 0)
  			break;
  		schedule();
  	}
  	current->state = TASK_RUNNING;

  	mutex_lock(&module_mutex);

  }
  
  asmlinkage long
  sys_delete_module(const char __user *name_user, unsigned int flags)
  {
  	struct module *mod;
  	char name[MODULE_NAME_LEN];
  	int ret, forced = 0;
  
  	if (!capable(CAP_SYS_MODULE))
  		return -EPERM;
  
  	if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
  		return -EFAULT;
  	name[MODULE_NAME_LEN-1] = '\0';

  	if (mutex_lock_interruptible(&module_mutex) != 0)

  		return -EINTR;
  
  	mod = find_module(name);
  	if (!mod) {
  		ret = -ENOENT;
  		goto out;
  	}
  
  	if (!list_empty(&mod->modules_which_use_me)) {
  		/* 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 and wake up
                     waiter --RR */
  		DEBUGP("%s already dying
  ", mod->name);
  		ret = -EBUSY;
  		goto out;
  	}
  
  	/* If it has an init func, it must have an exit func to unload */
  	if ((mod->init != NULL && mod->exit == NULL)
  	    || mod->unsafe) {

  		forced = try_force_unload(flags);

  		if (!forced) {
  			/* This module can't be removed */
  			ret = -EBUSY;
  			goto out;
  		}
  	}
  
  	/* Set this up before setting mod->state */
  	mod->waiter = current;
  
  	/* Stop the machine so refcounts can't move and disable module. */
  	ret = try_stop_module(mod, flags, &forced);
  	if (ret != 0)
  		goto out;
  
  	/* Never wait if forced. */
  	if (!forced && module_refcount(mod) != 0)
  		wait_for_zero_refcount(mod);
  
  	/* Final destruction now noone is using it. */
  	if (mod->exit != NULL) {

  		mutex_unlock(&module_mutex);

  		mod->exit();

  		mutex_lock(&module_mutex);

  	}
  	free_module(mod);
  
   out:

  	mutex_unlock(&module_mutex);

  	return ret;
  }
  
  static void print_unload_info(struct seq_file *m, struct module *mod)
  {
  	struct module_use *use;
  	int printed_something = 0;
  
  	seq_printf(m, " %u ", module_refcount(mod));
  
  	/* Always include a trailing , so userspace can differentiate
             between this and the old multi-field proc format. */
  	list_for_each_entry(use, &mod->modules_which_use_me, list) {
  		printed_something = 1;
  		seq_printf(m, "%s,", use->module_which_uses->name);
  	}
  
  	if (mod->unsafe) {
  		printed_something = 1;
  		seq_printf(m, "[unsafe],");
  	}
  
  	if (mod->init != NULL && mod->exit == NULL) {
  		printed_something = 1;
  		seq_printf(m, "[permanent],");
  	}
  
  	if (!printed_something)
  		seq_printf(m, "-");
  }
  
  void __symbol_put(const char *symbol)
  {
  	struct module *owner;
  	unsigned long flags;
  	const unsigned long *crc;
  
  	spin_lock_irqsave(&modlist_lock, flags);
  	if (!__find_symbol(symbol, &owner, &crc, 1))
  		BUG();
  	module_put(owner);
  	spin_unlock_irqrestore(&modlist_lock, flags);
  }
  EXPORT_SYMBOL(__symbol_put);
  
  void symbol_put_addr(void *addr)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&modlist_lock, flags);
  	if (!kernel_text_address((unsigned long)addr))
  		BUG();
  
  	module_put(module_text_address((unsigned long)addr));
  	spin_unlock_irqrestore(&modlist_lock, flags);
  }
  EXPORT_SYMBOL_GPL(symbol_put_addr);
  
  static ssize_t show_refcnt(struct module_attribute *mattr,
  			   struct module *mod, char *buffer)
  {
  	/* sysfs holds a reference */
  	return sprintf(buffer, "%u
  ", module_refcount(mod)-1);
  }
  
  static struct module_attribute refcnt = {
  	.attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
  	.show = show_refcnt,
  };
  
  #else /* !CONFIG_MODULE_UNLOAD */
  static void print_unload_info(struct seq_file *m, struct module *mod)
  {
  	/* We don't know the usage count, or what modules are using. */
  	seq_printf(m, " - -");
  }
  
  static inline void module_unload_free(struct module *mod)
  {
  }
  
  static inline int use_module(struct module *a, struct module *b)
  {
  	return strong_try_module_get(b);
  }
  
  static inline void module_unload_init(struct module *mod)
  {
  }
  #endif /* CONFIG_MODULE_UNLOAD */

  static struct module_attribute *modinfo_attrs[] = {
  	&modinfo_version,
  	&modinfo_srcversion,
  #ifdef CONFIG_MODULE_UNLOAD
  	&refcnt,
  #endif
  	NULL,
  };

  static const char vermagic[] = VERMAGIC_STRING;
  
  #ifdef CONFIG_MODVERSIONS
  static int check_version(Elf_Shdr *sechdrs,
  			 unsigned int versindex,
  			 const char *symname,
  			 struct module *mod, 
  			 const unsigned long *crc)
  {
  	unsigned int i, num_versions;
  	struct modversion_info *versions;
  
  	/* Exporting module didn't supply crcs?  OK, we're already tainted. */
  	if (!crc)
  		return 1;
  
  	versions = (void *) sechdrs[versindex].sh_addr;
  	num_versions = sechdrs[versindex].sh_size
  		/ sizeof(struct modversion_info);
  
  	for (i = 0; i < num_versions; i++) {
  		if (strcmp(versions[i].name, symname) != 0)
  			continue;
  
  		if (versions[i].crc == *crc)
  			return 1;
  		printk("%s: disagrees about version of symbol %s
  ",
  		       mod->name, symname);
  		DEBUGP("Found checksum %lX vs module %lX
  ",
  		       *crc, versions[i].crc);
  		return 0;
  	}
  	/* Not in module's version table.  OK, but that taints the kernel. */
  	if (!(tainted & TAINT_FORCED_MODULE)) {
  		printk("%s: no version for \"%s\" found: kernel tainted.
  ",
  		       mod->name, symname);

  		add_taint(TAINT_FORCED_MODULE);

  	}
  	return 1;
  }
  
  static inline int check_modstruct_version(Elf_Shdr *sechdrs,
  					  unsigned int versindex,
  					  struct module *mod)
  {
  	const unsigned long *crc;
  	struct module *owner;
  
  	if (!__find_symbol("struct_module", &owner, &crc, 1))
  		BUG();
  	return check_version(sechdrs, versindex, "struct_module", mod,
  			     crc);
  }
  
  /* First part is kernel version, which we ignore. */
  static inline int same_magic(const char *amagic, const char *bmagic)
  {
  	amagic += strcspn(amagic, " ");
  	bmagic += strcspn(bmagic, " ");
  	return strcmp(amagic, bmagic) == 0;
  }
  #else
  static inline int check_version(Elf_Shdr *sechdrs,
  				unsigned int versindex,
  				const char *symname,
  				struct module *mod, 
  				const unsigned long *crc)
  {
  	return 1;
  }
  
  static inline int check_modstruct_version(Elf_Shdr *sechdrs,
  					  unsigned int versindex,
  					  struct module *mod)
  {
  	return 1;
  }
  
  static inline int same_magic(const char *amagic, const char *bmagic)
  {
  	return strcmp(amagic, bmagic) == 0;
  }
  #endif /* CONFIG_MODVERSIONS */
  
  /* Resolve a symbol for this module.  I.e. if we find one, record usage.
     Must be holding module_mutex. */
  static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
  				    unsigned int versindex,
  				    const char *name,
  				    struct module *mod)
  {
  	struct module *owner;
  	unsigned long ret;
  	const unsigned long *crc;

  	ret = __find_symbol(name, &owner, &crc, mod->license_gplok);
  	if (ret) {
  		/* use_module can fail due to OOM, or module unloading */
  		if (!check_version(sechdrs, versindex, name, mod, crc) ||
  		    !use_module(mod, owner))
  			ret = 0;
  	}

  	return ret;
  }
  
  
  /*
   * /sys/module/foo/sections stuff
   * J. Corbet <corbet@lwn.net>
   */
  #ifdef CONFIG_KALLSYMS
  static ssize_t module_sect_show(struct module_attribute *mattr,
  				struct module *mod, char *buf)
  {
  	struct module_sect_attr *sattr =
  		container_of(mattr, struct module_sect_attr, mattr);
  	return sprintf(buf, "0x%lx
  ", sattr->address);
  }
  
  static void add_sect_attrs(struct module *mod, unsigned int nsect,
  		char *secstrings, Elf_Shdr *sechdrs)
  {
  	unsigned int nloaded = 0, i, size[2];
  	struct module_sect_attrs *sect_attrs;
  	struct module_sect_attr *sattr;
  	struct attribute **gattr;
  	
  	/* Count loaded sections and allocate structures */
  	for (i = 0; i < nsect; i++)
  		if (sechdrs[i].sh_flags & SHF_ALLOC)
  			nloaded++;
  	size[0] = ALIGN(sizeof(*sect_attrs)
  			+ nloaded * sizeof(sect_attrs->attrs[0]),
  			sizeof(sect_attrs->grp.attrs[0]));
  	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
  	if (! (sect_attrs = kmalloc(size[0] + size[1], GFP_KERNEL)))
  		return;
  
  	/* Setup section attributes. */
  	sect_attrs->grp.name = "sections";
  	sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
  
  	sattr = &sect_attrs->attrs[0];
  	gattr = &sect_attrs->grp.attrs[0];
  	for (i = 0; i < nsect; i++) {
  		if (! (sechdrs[i].sh_flags & SHF_ALLOC))
  			continue;
  		sattr->address = sechdrs[i].sh_addr;
  		strlcpy(sattr->name, secstrings + sechdrs[i].sh_name,
  			MODULE_SECT_NAME_LEN);
  		sattr->mattr.show = module_sect_show;
  		sattr->mattr.store = NULL;
  		sattr->mattr.attr.name = sattr->name;
  		sattr->mattr.attr.owner = mod;
  		sattr->mattr.attr.mode = S_IRUGO;
  		*(gattr++) = &(sattr++)->mattr.attr;
  	}
  	*gattr = NULL;
  
  	if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
  		goto out;
  
  	mod->sect_attrs = sect_attrs;
  	return;
    out:
  	kfree(sect_attrs);
  }
  
  static void remove_sect_attrs(struct module *mod)
  {
  	if (mod->sect_attrs) {
  		sysfs_remove_group(&mod->mkobj.kobj,
  				   &mod->sect_attrs->grp);
  		/* We are positive that no one is using any sect attrs
  		 * at this point.  Deallocate immediately. */
  		kfree(mod->sect_attrs);
  		mod->sect_attrs = NULL;
  	}
  }
  
  
  #else
  static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
  		char *sectstrings, Elf_Shdr *sechdrs)
  {
  }
  
  static inline void remove_sect_attrs(struct module *mod)
  {
  }
  #endif /* CONFIG_KALLSYMS */

  static int module_add_modinfo_attrs(struct module *mod)
  {
  	struct module_attribute *attr;

  	struct module_attribute *temp_attr;

  	int error = 0;
  	int i;

  	mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
  					(ARRAY_SIZE(modinfo_attrs) + 1)),
  					GFP_KERNEL);
  	if (!mod->modinfo_attrs)
  		return -ENOMEM;
  
  	temp_attr = mod->modinfo_attrs;

  	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
  		if (!attr->test ||

  		    (attr->test && attr->test(mod))) {
  			memcpy(temp_attr, attr, sizeof(*temp_attr));
  			temp_attr->attr.owner = mod;
  			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
  			++temp_attr;
  		}

  	}
  	return error;
  }
  
  static void module_remove_modinfo_attrs(struct module *mod)
  {
  	struct module_attribute *attr;
  	int i;

  	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
  		/* pick a field to test for end of list */
  		if (!attr->attr.name)
  			break;

  		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);

  		if (attr->free)
  			attr->free(mod);

  	}

  	kfree(mod->modinfo_attrs);

  }

  
  static int mod_sysfs_setup(struct module *mod,
  			   struct kernel_param *kparam,
  			   unsigned int num_params)
  {
  	int err;
  
  	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
  	err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
  	if (err)
  		goto out;
  	kobj_set_kset_s(&mod->mkobj, module_subsys);
  	mod->mkobj.mod = mod;
  	err = kobject_register(&mod->mkobj.kobj);
  	if (err)
  		goto out;

  	err = module_param_sysfs_setup(mod, kparam, num_params);
  	if (err)
  		goto out_unreg;

  	err = module_add_modinfo_attrs(mod);
  	if (err)
  		goto out_unreg;

  	return 0;
  
  out_unreg:
  	kobject_unregister(&mod->mkobj.kobj);
  out:
  	return err;
  }
  
  static void mod_kobject_remove(struct module *mod)
  {

  	module_remove_modinfo_attrs(mod);

  	module_param_sysfs_remove(mod);
  
  	kobject_unregister(&mod->mkobj.kobj);
  }
  
  /*
   * unlink the module with the whole machine is stopped with interrupts off
   * - this defends against kallsyms not taking locks
   */
  static int __unlink_module(void *_mod)
  {
  	struct module *mod = _mod;
  	list_del(&mod->list);
  	return 0;
  }
  
  /* Free a module, remove from lists, etc (must hold module mutex). */
  static void free_module(struct module *mod)
  {
  	/* Delete from various lists */
  	stop_machine_run(__unlink_module, mod, NR_CPUS);
  	remove_sect_attrs(mod);
  	mod_kobject_remove(mod);
  
  	/* Arch-specific cleanup. */
  	module_arch_cleanup(mod);
  
  	/* Module unload stuff */
  	module_unload_free(mod);
  
  	/* This may be NULL, but that's OK */
  	module_free(mod, mod->module_init);
  	kfree(mod->args);
  	if (mod->percpu)
  		percpu_modfree(mod->percpu);
  
  	/* Finally, free the core (containing the module structure) */
  	module_free(mod, mod->module_core);
  }
  
  void *__symbol_get(const char *symbol)
  {
  	struct module *owner;
  	unsigned long value, flags;
  	const unsigned long *crc;
  
  	spin_lock_irqsave(&modlist_lock, flags);
  	value = __find_symbol(symbol, &owner, &crc, 1);
  	if (value && !strong_try_module_get(owner))
  		value = 0;
  	spin_unlock_irqrestore(&modlist_lock, flags);
  
  	return (void *)value;
  }
  EXPORT_SYMBOL_GPL(__symbol_get);

  /*
   * Ensure that an exported symbol [global namespace] does not already exist
   * in the Kernel or in some other modules exported symbol table.
   */
  static int verify_export_symbols(struct module *mod)
  {
  	const char *name = NULL;
  	unsigned long i, ret = 0;
  	struct module *owner;
  	const unsigned long *crc;
  
  	for (i = 0; i < mod->num_syms; i++)
  	        if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
  			name = mod->syms[i].name;
  			ret = -ENOEXEC;
  			goto dup;
  		}
  
  	for (i = 0; i < mod->num_gpl_syms; i++)
  	        if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
  			name = mod->gpl_syms[i].name;
  			ret = -ENOEXEC;
  			goto dup;
  		}
  
  dup:
  	if (ret)
  		printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)
  ",
  			mod->name, name, module_name(owner));
  
  	return ret;
  }

  /* Change all symbols so that sh_value encodes the pointer directly. */
  static int simplify_symbols(Elf_Shdr *sechdrs,
  			    unsigned int symindex,
  			    const char *strtab,
  			    unsigned int versindex,
  			    unsigned int pcpuindex,
  			    struct module *mod)
  {
  	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
  	unsigned long secbase;
  	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
  	int ret = 0;
  
  	for (i = 1; i < n; i++) {
  		switch (sym[i].st_shndx) {
  		case SHN_COMMON:
  			/* We compiled with -fno-common.  These are not
  			   supposed to happen.  */
  			DEBUGP("Common symbol: %s
  ", strtab + sym[i].st_name);
  			printk("%s: please compile with -fno-common
  ",
  			       mod->name);
  			ret = -ENOEXEC;
  			break;
  
  		case SHN_ABS:
  			/* Don't need to do anything */
  			DEBUGP("Absolute symbol: 0x%08lx
  ",
  			       (long)sym[i].st_value);
  			break;
  
  		case SHN_UNDEF:
  			sym[i].st_value
  			  = resolve_symbol(sechdrs, versindex,
  					   strtab + sym[i].st_name, mod);
  
  			/* Ok if resolved.  */
  			if (sym[i].st_value != 0)
  				break;
  			/* Ok if weak.  */
  			if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
  				break;
  
  			printk(KERN_WARNING "%s: Unknown symbol %s
  ",
  			       mod->name, strtab + sym[i].st_name);
  			ret = -ENOENT;
  			break;
  
  		default:
  			/* Divert to percpu allocation if a percpu var. */
  			if (sym[i].st_shndx == pcpuindex)
  				secbase = (unsigned long)mod->percpu;
  			else
  				secbase = sechdrs[sym[i].st_shndx].sh_addr;
  			sym[i].st_value += secbase;
  			break;
  		}
  	}
  
  	return ret;
  }
  
  /* Update size with this section: return offset. */
  static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
  {
  	long ret;
  
  	ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
  	*size = ret + sechdr->sh_size;
  	return ret;
  }
  
  /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
     might -- code, read-only data, read-write data, small data.  Tally
     sizes, and place the offsets into sh_entsize fields: high bit means it
     belongs in init. */
  static void layout_sections(struct module *mod,
  			    const Elf_Ehdr *hdr,
  			    Elf_Shdr *sechdrs,
  			    const char *secstrings)
  {
  	static unsigned long const masks[][2] = {
  		/* NOTE: all executable code must be the first section
  		 * in this array; otherwise modify the text_size
  		 * finder in the two loops below */
  		{ SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
  		{ SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
  		{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
  		{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
  	};
  	unsigned int m, i;
  
  	for (i = 0; i < hdr->e_shnum; i++)
  		sechdrs[i].sh_entsize = ~0UL;
  
  	DEBUGP("Core section allocation order:
  ");
  	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
  		for (i = 0; i < hdr->e_shnum; ++i) {
  			Elf_Shdr *s = &sechdrs[i];
  
  			if ((s->sh_flags & masks[m][0]) != masks[m][0]
  			    || (s->sh_flags & masks[m][1])
  			    || s->sh_entsize != ~0UL
  			    || strncmp(secstrings + s->sh_name,
  				       ".init", 5) == 0)
  				continue;
  			s->sh_entsize = get_offset(&mod->core_size, s);
  			DEBUGP("\t%s
  ", secstrings + s->sh_name);
  		}
  		if (m == 0)
  			mod->core_text_size = mod->core_size;
  	}
  
  	DEBUGP("Init section allocation order:
  ");
  	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
  		for (i = 0; i < hdr->e_shnum; ++i) {
  			Elf_Shdr *s = &sechdrs[i];
  
  			if ((s->sh_flags & masks[m][0]) != masks[m][0]
  			    || (s->sh_flags & masks[m][1])
  			    || s->sh_entsize != ~0UL
  			    || strncmp(secstrings + s->sh_name,
  				       ".init", 5) != 0)
  				continue;
  			s->sh_entsize = (get_offset(&mod->init_size, s)
  					 | INIT_OFFSET_MASK);
  			DEBUGP("\t%s
  ", secstrings + s->sh_name);
  		}
  		if (m == 0)
  			mod->init_text_size = mod->init_size;
  	}
  }
  
  static inline int license_is_gpl_compatible(const char *license)
  {
  	return (strcmp(license, "GPL") == 0
  		|| strcmp(license, "GPL v2") == 0
  		|| strcmp(license, "GPL and additional rights") == 0
  		|| strcmp(license, "Dual BSD/GPL") == 0
  		|| strcmp(license, "Dual MPL/GPL") == 0);
  }
  
  static void set_license(struct module *mod, const char *license)
  {
  	if (!license)
  		license = "unspecified";
  
  	mod->license_gplok = license_is_gpl_compatible(license);
  	if (!mod->license_gplok && !(tainted & TAINT_PROPRIETARY_MODULE)) {
  		printk(KERN_WARNING "%s: module license '%s' taints kernel.
  ",
  		       mod->name, license);

  		add_taint(TAINT_PROPRIETARY_MODULE);

  	}
  }
  
  /* Parse tag=value strings from .modinfo section */
  static char *next_string(char *string, unsigned long *secsize)
  {
  	/* Skip non-zero chars */
  	while (string[0]) {
  		string++;
  		if ((*secsize)-- <= 1)
  			return NULL;
  	}
  
  	/* Skip any zero padding. */
  	while (!string[0]) {
  		string++;
  		if ((*secsize)-- <= 1)
  			return NULL;
  	}
  	return string;
  }
  
  static char *get_modinfo(Elf_Shdr *sechdrs,
  			 unsigned int info,
  			 const char *tag)
  {
  	char *p;
  	unsigned int taglen = strlen(tag);
  	unsigned long size = sechdrs[info].sh_size;
  
  	for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
  		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
  			return p + taglen + 1;
  	}
  	return NULL;
  }

  static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
  			  unsigned int infoindex)
  {
  	struct module_attribute *attr;
  	int i;
  
  	for (i = 0; (attr = modinfo_attrs[i]); i++) {
  		if (attr->setup)
  			attr->setup(mod,
  				    get_modinfo(sechdrs,
  						infoindex,
  						attr->attr.name));
  	}
  }

  #ifdef CONFIG_KALLSYMS
  int is_exported(const char *name, const struct module *mod)
  {

  	if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
  		return 1;
  	else
  		if (lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))

  			return 1;

  		else
  			return 0;

  }
  
  /* As per nm */
  static char elf_type(const Elf_Sym *sym,
  		     Elf_Shdr *sechdrs,
  		     const char *secstrings,
  		     struct module *mod)
  {
  	if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
  		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
  			return 'v';
  		else
  			return 'w';
  	}
  	if (sym->st_shndx == SHN_UNDEF)
  		return 'U';
  	if (sym->st_shndx == SHN_ABS)
  		return 'a';
  	if (sym->st_shndx >= SHN_LORESERVE)
  		return '?';
  	if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
  		return 't';
  	if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
  	    && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
  		if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
  			return 'r';
  		else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
  			return 'g';
  		else
  			return 'd';
  	}
  	if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
  		if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
  			return 's';
  		else
  			return 'b';
  	}
  	if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
  		    ".debug", strlen(".debug")) == 0)
  		return 'n';
  	return '?';
  }
  
  static void add_kallsyms(struct module *mod,
  			 Elf_Shdr *sechdrs,
  			 unsigned int symindex,
  			 unsigned int strindex,
  			 const char *secstrings)
  {
  	unsigned int i;
  
  	mod->symtab = (void *)sechdrs[symindex].sh_addr;
  	mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
  	mod->strtab = (void *)sechdrs[strindex].sh_addr;
  
  	/* Set types up while we still have access to sections. */
  	for (i = 0; i < mod->num_symtab; i++)
  		mod->symtab[i].st_info
  			= elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
  }
  #else
  static inline void add_kallsyms(struct module *mod,
  				Elf_Shdr *sechdrs,
  				unsigned int symindex,
  				unsigned int strindex,
  				const char *secstrings)
  {
  }
  #endif /* CONFIG_KALLSYMS */
  
  /* Allocate and load the module: note that size of section 0 is always
     zero, and we rely on this for optional sections. */
  static struct module *load_module(void __user *umod,
  				  unsigned long len,
  				  const char __user *uargs)
  {
  	Elf_Ehdr *hdr;
  	Elf_Shdr *sechdrs;
  	char *secstrings, *args, *modmagic, *strtab = NULL;
  	unsigned int i, symindex = 0, strindex = 0, setupindex, exindex,
  		exportindex, modindex, obsparmindex, infoindex, gplindex,

  		crcindex, gplcrcindex, versindex, pcpuindex, gplfutureindex,
  		gplfuturecrcindex;

  	struct module *mod;
  	long err = 0;
  	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
  	struct exception_table_entry *extable;

  	mm_segment_t old_fs;

  
  	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p
  ",
  	       umod, len, uargs);
  	if (len < sizeof(*hdr))
  		return ERR_PTR(-ENOEXEC);
  
  	/* Suck in entire file: we'll want most of it. */
  	/* vmalloc barfs on "unusual" numbers.  Check here */
  	if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
  		return ERR_PTR(-ENOMEM);
  	if (copy_from_user(hdr, umod, len) != 0) {
  		err = -EFAULT;
  		goto free_hdr;
  	}
  
  	/* Sanity checks against insmoding binaries or wrong arch,
             weird elf version */
  	if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
  	    || hdr->e_type != ET_REL
  	    || !elf_check_arch(hdr)
  	    || hdr->e_shentsize != sizeof(*sechdrs)) {
  		err = -ENOEXEC;
  		goto free_hdr;
  	}
  
  	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
  		goto truncated;
  
  	/* Convenience variables */
  	sechdrs = (void *)hdr + hdr->e_shoff;
  	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
  	sechdrs[0].sh_addr = 0;
  
  	for (i = 1; i < hdr->e_shnum; i++) {
  		if (sechdrs[i].sh_type != SHT_NOBITS
  		    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
  			goto truncated;
  
  		/* Mark all sections sh_addr with their address in the
  		   temporary image. */
  		sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
  
  		/* Internal symbols and strings. */
  		if (sechdrs[i].sh_type == SHT_SYMTAB) {
  			symindex = i;
  			strindex = sechdrs[i].sh_link;
  			strtab = (char *)hdr + sechdrs[strindex].sh_offset;
  		}
  #ifndef CONFIG_MODULE_UNLOAD
  		/* Don't load .exit sections */
  		if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
  			sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
  #endif
  	}
  
  	modindex = find_sec(hdr, sechdrs, secstrings,
  			    ".gnu.linkonce.this_module");
  	if (!modindex) {
  		printk(KERN_WARNING "No module found in object
  ");
  		err = -ENOEXEC;
  		goto free_hdr;
  	}
  	mod = (void *)sechdrs[modindex].sh_addr;
  
  	if (symindex == 0) {
  		printk(KERN_WARNING "%s: module has no symbols (stripped?)
  ",
  		       mod->name);
  		err = -ENOEXEC;
  		goto free_hdr;
  	}
  
  	/* Optional sections */
  	exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
  	gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");

  	gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");

  	crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
  	gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");

  	gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");

  	setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
  	exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
  	obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
  	versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
  	infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
  	pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
  
  	/* Don't keep modinfo section */
  	sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
  #ifdef CONFIG_KALLSYMS
  	/* Keep symbol and string tables for decoding later. */
  	sechdrs[symindex].sh_flags |= SHF_ALLOC;
  	sechdrs[strindex].sh_flags |= SHF_ALLOC;
  #endif
  
  	/* Check module struct version now, before we try to use module. */
  	if (!check_modstruct_version(sechdrs, versindex, mod)) {
  		err = -ENOEXEC;
  		goto free_hdr;
  	}
  
  	modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
  	/* This is allowed: modprobe --force will invalidate it. */
  	if (!modmagic) {

  		add_taint(TAINT_FORCED_MODULE);

  		printk(KERN_WARNING "%s: no version magic, tainting kernel.
  ",
  		       mod->name);
  	} else if (!same_magic(modmagic, vermagic)) {
  		printk(KERN_ERR "%s: version magic '%s' should be '%s'
  ",
  		       mod->name, modmagic, vermagic);
  		err = -ENOEXEC;
  		goto free_hdr;
  	}
  
  	/* Now copy in args */

  	args = strndup_user(uargs, ~0UL >> 1);
  	if (IS_ERR(args)) {
  		err = PTR_ERR(args);

  		goto free_hdr;
  	}

  	if (find_module(mod->name)) {
  		err = -EEXIST;
  		goto free_mod;
  	}
  
  	mod->state = MODULE_STATE_COMING;
  
  	/* Allow arches to frob section contents and sizes.  */
  	err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
  	if (err < 0)
  		goto free_mod;
  
  	if (pcpuindex) {
  		/* We have a special allocation for this section. */
  		percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,

  					 sechdrs[pcpuindex].sh_addralign,
  					 mod->name);

  		if (!percpu) {
  			err = -ENOMEM;
  			goto free_mod;
  		}
  		sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
  		mod->percpu = percpu;
  	}
  
  	/* 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(mod, hdr, sechdrs, secstrings);
  
  	/* Do the allocs. */
  	ptr = module_alloc(mod->core_size);
  	if (!ptr) {
  		err = -ENOMEM;
  		goto free_percpu;
  	}
  	memset(ptr, 0, mod->core_size);
  	mod->module_core = ptr;
  
  	ptr = module_alloc(mod->init_size);
  	if (!ptr && mod->init_size) {
  		err = -ENOMEM;
  		goto free_core;
  	}
  	memset(ptr, 0, mod->init_size);
  	mod->module_init = ptr;
  
  	/* Transfer each section which specifies SHF_ALLOC */
  	DEBUGP("final section addresses:
  ");
  	for (i = 0; i < hdr->e_shnum; i++) {
  		void *dest;
  
  		if (!(sechdrs[i].sh_flags & SHF_ALLOC))
  			continue;
  
  		if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
  			dest = mod->module_init
  				+ (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
  		else
  			dest = mod->module_core + sechdrs[i].sh_entsize;
  
  		if (sechdrs[i].sh_type != SHT_NOBITS)
  			memcpy(dest, (void *)sechdrs[i].sh_addr,
  			       sechdrs[i].sh_size);
  		/* Update sh_addr to point to copy in image. */
  		sechdrs[i].sh_addr = (unsigned long)dest;
  		DEBUGP("\t0x%lx %s
  ", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
  	}
  	/* Module has been moved. */
  	mod = (void *)sechdrs[modindex].sh_addr;
  
  	/* Now we've moved module, initialize linked lists, etc. */
  	module_unload_init(mod);
  
  	/* Set up license info based on the info section */
  	set_license(mod, get_modinfo(sechdrs, infoindex, "license"));

  	if (strcmp(mod->name, "ndiswrapper") == 0)
  		add_taint(TAINT_PROPRIETARY_MODULE);
  	if (strcmp(mod->name, "driverloader") == 0)
  		add_taint(TAINT_PROPRIETARY_MODULE);

  	/* Set up MODINFO_ATTR fields */
  	setup_modinfo(mod, sechdrs, infoindex);

  	/* Fix up syms, so that st_value is a pointer to location. */
  	err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
  			       mod);
  	if (err < 0)
  		goto cleanup;
  
  	/* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
  	mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
  	mod->syms = (void *)sechdrs[exportindex].sh_addr;
  	if (crcindex)
  		mod->crcs = (void *)sechdrs[crcindex].sh_addr;
  	mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
  	mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
  	if (gplcrcindex)
  		mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;

  	mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
  					sizeof(*mod->gpl_future_syms);
  	mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
  	if (gplfuturecrcindex)
  		mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;

  
  #ifdef CONFIG_MODVERSIONS
  	if ((mod->num_syms && !crcindex) || 

  	    (mod->num_gpl_syms && !gplcrcindex) ||
  	    (mod->num_gpl_future_syms && !gplfuturecrcindex)) {

  		printk(KERN_WARNING "%s: No versions for exported symbols."
  		       " Tainting kernel.
  ", mod->name);

  		add_taint(TAINT_FORCED_MODULE);

  	}
  #endif
  
  	/* Now do relocations. */
  	for (i = 1; i < hdr->e_shnum; i++) {
  		const char *strtab = (char *)sechdrs[strindex].sh_addr;
  		unsigned int info = sechdrs[i].sh_info;
  
  		/* Not a valid relocation section? */
  		if (info >= hdr->e_shnum)
  			continue;
  
  		/* Don't bother with non-allocated sections */
  		if (!(sechdrs[info].sh_flags & SHF_ALLOC))
  			continue;
  
  		if (sechdrs[i].sh_type == SHT_REL)
  			err = apply_relocate(sechdrs, strtab, symindex, i,mod);
  		else if (sechdrs[i].sh_type == SHT_RELA)
  			err = apply_relocate_add(sechdrs, strtab, symindex, i,
  						 mod);
  		if (err < 0)
  			goto cleanup;
  	}

          /* Find duplicate symbols */
  	err = verify_export_symbols(mod);
  
  	if (err < 0)
  		goto cleanup;

    	/* Set up and sort exception table */
  	mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
  	mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
  	sort_extable(extable, extable + mod->num_exentries);
  
  	/* Finally, copy percpu area over. */
  	percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
  		       sechdrs[pcpuindex].sh_size);
  
  	add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
  
  	err = module_finalize(hdr, sechdrs, mod);
  	if (err < 0)
  		goto cleanup;

  	/* flush the icache in correct context */
  	old_fs = get_fs();
  	set_fs(KERNEL_DS);
  
  	/*
  	 * Flush the instruction cache, since we've played with text.
  	 * Do it before processing of module parameters, so the module
  	 * can provide parameter accessor functions of its own.
  	 */
  	if (mod->module_init)
  		flush_icache_range((unsigned long)mod->module_init,
  				   (unsigned long)mod->module_init
  				   + mod->init_size);
  	flush_icache_range((unsigned long)mod->module_core,
  			   (unsigned long)mod->module_core + mod->core_size);
  
  	set_fs(old_fs);

  	mod->args = args;

  	if (obsparmindex)
  		printk(KERN_WARNING "%s: Ignoring obsolete parameters
  ",
  		       mod->name);
  
  	/* Size of section 0 is 0, so this works well if no params */
  	err = parse_args(mod->name, mod->args,
  			 (struct kernel_param *)
  			 sechdrs[setupindex].sh_addr,
  			 sechdrs[setupindex].sh_size
  			 / sizeof(struct kernel_param),
  			 NULL);

  	if (err < 0)
  		goto arch_cleanup;
  
  	err = mod_sysfs_setup(mod, 
  			      (struct kernel_param *)
  			      sechdrs[setupindex].sh_addr,
  			      sechdrs[setupindex].sh_size
  			      / sizeof(struct kernel_param));
  	if (err < 0)
  		goto arch_cleanup;
  	add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
  
  	/* Get rid of temporary copy */
  	vfree(hdr);
  
  	/* Done! */
  	return mod;
  
   arch_cleanup:
  	module_arch_cleanup(mod);
   cleanup:
  	module_unload_free(mod);
  	module_free(mod, mod->module_init);
   free_core:
  	module_free(mod, mod->module_core);
   free_percpu:
  	if (percpu)
  		percpu_modfree(percpu);
   free_mod:
  	kfree(args);
   free_hdr:
  	vfree(hdr);

  	return ERR_PTR(err);

  
   truncated:
  	printk(KERN_ERR "Module len %lu truncated
  ", len);
  	err = -ENOEXEC;
  	goto free_hdr;
  }
  
  /*
   * link the module with the whole machine is stopped with interrupts off
   * - this defends against kallsyms not taking locks
   */
  static int __link_module(void *_mod)
  {
  	struct module *mod = _mod;
  	list_add(&mod->list, &modules);
  	return 0;
  }
  
  /* This is where the real work happens */
  asmlinkage long
  sys_init_module(void __user *umod,
  		unsigned long len,
  		const char __user *uargs)
  {
  	struct module *mod;
  	int ret = 0;
  
  	/* Must have permission */
  	if (!capable(CAP_SYS_MODULE))
  		return -EPERM;
  
  	/* Only one module load at a time, please */

  	if (mutex_lock_interruptible(&module_mutex) != 0)

  		return -EINTR;
  
  	/* Do all the hard work */
  	mod = load_module(umod, len, uargs);
  	if (IS_ERR(mod)) {

  		mutex_unlock(&module_mutex);

  		return PTR_ERR(mod);
  	}

  	/* Now sew it into the lists.  They won't access us, since
             strong_try_module_get() will fail. */
  	stop_machine_run(__link_module, mod, NR_CPUS);
  
  	/* Drop lock so they can recurse */

  	mutex_unlock(&module_mutex);

  	mutex_lock(&notify_mutex);

  	notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod);

  	mutex_unlock(&notify_mutex);

  
  	/* Start the module */
  	if (mod->init != NULL)
  		ret = mod->init();
  	if (ret < 0) {
  		/* Init routine failed: abort.  Try to protect us from
                     buggy refcounters. */
  		mod->state = MODULE_STATE_GOING;

  		synchronize_sched();

  		if (mod->unsafe)
  			printk(KERN_ERR "%s: module is now stuck!
  ",
  			       mod->name);
  		else {
  			module_put(mod);

  			mutex_lock(&module_mutex);

  			free_module(mod);

  			mutex_unlock(&module_mutex);

  		}
  		return ret;
  	}
  
  	/* Now it's a first class citizen! */

  	mutex_lock(&module_mutex);

  	mod->state = MODULE_STATE_LIVE;
  	/* Drop initial reference. */
  	module_put(mod);
  	module_free(mod, mod->module_init);
  	mod->module_init = NULL;
  	mod->init_size = 0;
  	mod->init_text_size = 0;

  	mutex_unlock(&module_mutex);

  
  	return 0;
  }
  
  static inline int within(unsigned long addr, void *start, unsigned long size)
  {
  	return ((void *)addr >= start && (void *)addr < start + size);
  }
  
  #ifdef CONFIG_KALLSYMS
  /*
   * This ignores the intensely annoying "mapping symbols" found
   * in ARM ELF files: $a, $t and $d.
   */
  static inline int is_arm_mapping_symbol(const char *str)
  {
  	return str[0] == '$' && strchr("atd", str[1]) 
  	       && (str[2] == '\0' || str[2] == '.');
  }
  
  static const char *get_ksymbol(struct module *mod,
  			       unsigned long addr,
  			       unsigned long *size,
  			       unsigned long *offset)
  {
  	unsigned int i, best = 0;
  	unsigned long nextval;
  
  	/* At worse, next value is at end of module */
  	if (within(addr, mod->module_init, mod->init_size))
  		nextval = (unsigned long)mod->module_init+mod->init_text_size;
  	else 
  		nextval = (unsigned long)mod->module_core+mod->core_text_size;
  
  	/* Scan for closest preceeding symbol, and next symbol. (ELF
             starts real symbols at 1). */
  	for (i = 1; i < mod->num_symtab; i++) {
  		if (mod->symtab[i].st_shndx == SHN_UNDEF)
  			continue;
  
  		/* We ignore unnamed symbols: they're uninformative
  		 * and inserted at a whim. */
  		if (mod->symtab[i].st_value <= addr
  		    && mod->symtab[i].st_value > mod->symtab[best].st_value
  		    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
  		    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
  			best = i;
  		if (mod->symtab[i].st_value > addr
  		    && mod->symtab[i].st_value < nextval
  		    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
  		    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
  			nextval = mod->symtab[i].st_value;
  	}
  
  	if (!best)
  		return NULL;
  
  	*size = nextval - mod->symtab[best].st_value;
  	*offset = addr - mod->symtab[best].st_value;
  	return mod->strtab + mod->symtab[best].st_name;
  }
  
  /* For kallsyms to ask for address resolution.  NULL means not found.
     We don't lock, as this is used for oops resolution and races are a
     lesser concern. */
  const char *module_address_lookup(unsigned long addr,
  				  unsigned long *size,
  				  unsigned long *offset,
  				  char **modname)
  {
  	struct module *mod;
  
  	list_for_each_entry(mod, &modules, list) {
  		if (within(addr, mod->module_init, mod->init_size)
  		    || within(addr, mod->module_core, mod->core_size)) {
  			*modname = mod->name;
  			return get_ksymbol(mod, addr, size, offset);
  		}
  	}
  	return NULL;
  }
  
  struct module *module_get_kallsym(unsigned int symnum,
  				  unsigned long *value,
  				  char *type,
  				  char namebuf[128])
  {
  	struct module *mod;

  	mutex_lock(&module_mutex);

  	list_for_each_entry(mod, &modules, list) {
  		if (symnum < mod->num_symtab) {
  			*value = mod->symtab[symnum].st_value;
  			*type = mod->symtab[symnum].st_info;
  			strncpy(namebuf,
  				mod->strtab + mod->symtab[symnum].st_name,
  				127);

  			mutex_unlock(&module_mutex);

  			return mod;
  		}
  		symnum -= mod->num_symtab;
  	}

  	mutex_unlock(&module_mutex);

  	return NULL;
  }
  
  static unsigned long mod_find_symname(struct module *mod, const char *name)
  {
  	unsigned int i;
  
  	for (i = 0; i < mod->num_symtab; i++)

  		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
  		    mod->symtab[i].st_info != 'U')

  			return mod->symtab[i].st_value;
  	return 0;
  }
  
  /* Look for this name: can be of form module:name. */
  unsigned long module_kallsyms_lookup_name(const char *name)
  {
  	struct module *mod;
  	char *colon;
  	unsigned long ret = 0;
  
  	/* Don't lock: we're in enough trouble already. */
  	if ((colon = strchr(name, ':')) != NULL) {
  		*colon = '\0';
  		if ((mod = find_module(name)) != NULL)
  			ret = mod_find_symname(mod, colon+1);
  		*colon = ':';
  	} else {
  		list_for_each_entry(mod, &modules, list)
  			if ((ret = mod_find_symname(mod, name)) != 0)
  				break;
  	}
  	return ret;
  }
  #endif /* CONFIG_KALLSYMS */
  
  /* Called by the /proc file system to return a list of modules. */
  static void *m_start(struct seq_file *m, loff_t *pos)
  {
  	struct list_head *i;
  	loff_t n = 0;

  	mutex_lock(&module_mutex);

  	list_for_each(i, &modules) {
  		if (n++ == *pos)
  			break;
  	}
  	if (i == &modules)
  		return NULL;
  	return i;
  }
  
  static void *m_next(struct seq_file *m, void *p, loff_t *pos)
  {
  	struct list_head *i = p;
  	(*pos)++;
  	if (i->next == &modules)
  		return NULL;
  	return i->next;
  }
  
  static void m_stop(struct seq_file *m, void *p)
  {

  	mutex_unlock(&module_mutex);

  }
  
  static int m_show(struct seq_file *m, void *p)
  {
  	struct module *mod = list_entry(p, struct module, list);
  	seq_printf(m, "%s %lu",
  		   mod->name, mod->init_size + mod->core_size);
  	print_unload_info(m, mod);
  
  	/* Informative for users. */
  	seq_printf(m, " %s",
  		   mod->state == MODULE_STATE_GOING ? "Unloading":
  		   mod->state == MODULE_STATE_COMING ? "Loading":
  		   "Live");
  	/* Used by oprofile and other similar tools. */
  	seq_printf(m, " 0x%p", mod->module_core);
  
  	seq_printf(m, "
  ");
  	return 0;
  }
  
  /* Format: modulename size refcount deps address
  
     Where refcount is a number or -, and deps is a comma-separated list
     of depends or -.
  */
  struct seq_operations modules_op = {
  	.start	= m_start,
  	.next	= m_next,
  	.stop	= m_stop,
  	.show	= m_show
  };
  
  /* Given an address, look for it in the module exception tables. */
  const struct exception_table_entry *search_module_extables(unsigned long addr)
  {
  	unsigned long flags;
  	const struct exception_table_entry *e = NULL;
  	struct module *mod;
  
  	spin_lock_irqsave(&modlist_lock, flags);
  	list_for_each_entry(mod, &modules, list) {
  		if (mod->num_exentries == 0)
  			continue;
  				
  		e = search_extable(mod->extable,
  				   mod->extable + mod->num_exentries - 1,
  				   addr);
  		if (e)
  			break;
  	}
  	spin_unlock_irqrestore(&modlist_lock, flags);
  
  	/* Now, if we found one, we are running inside it now, hence
             we cannot unload the module, hence no refcnt needed. */
  	return e;
  }
  
  /* Is this a valid kernel address?  We don't grab the lock: we are oopsing. */
  struct module *__module_text_address(unsigned long addr)
  {
  	struct module *mod;
  
  	list_for_each_entry(mod, &modules, list)
  		if (within(addr, mod->module_init, mod->init_text_size)
  		    || within(addr, mod->module_core, mod->core_text_size))
  			return mod;
  	return NULL;
  }
  
  struct module *module_text_address(unsigned long addr)
  {
  	struct module *mod;
  	unsigned long flags;
  
  	spin_lock_irqsave(&modlist_lock, flags);
  	mod = __module_text_address(addr);
  	spin_unlock_irqrestore(&modlist_lock, flags);
  
  	return mod;
  }
  
  /* Don't grab lock, we're oopsing. */
  void print_modules(void)
  {
  	struct module *mod;
  
  	printk("Modules linked in:");
  	list_for_each_entry(mod, &modules, list)
  		printk(" %s", mod->name);
  	printk("
  ");
  }
  
  void module_add_driver(struct module *mod, struct device_driver *drv)
  {
  	if (!mod || !drv)
  		return;
  
  	/* Don't check return code; this call is idempotent */
  	sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
  }
  EXPORT_SYMBOL(module_add_driver);
  
  void module_remove_driver(struct device_driver *drv)
  {
  	if (!drv)
  		return;
  	sysfs_remove_link(&drv->kobj, "module");
  }
  EXPORT_SYMBOL(module_remove_driver);
  
  #ifdef CONFIG_MODVERSIONS
  /* Generate the signature for struct module here, too, for modversions. */
  void struct_module(struct module *mod) { return; }
  EXPORT_SYMBOL(struct_module);
  #endif