module.c 72.2 KB
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/*
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   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/module.h>
#include <linux/moduleloader.h>
#include <linux/init.h>
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#include <linux/kallsyms.h>
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#include <linux/fs.h>
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#include <linux/sysfs.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <linux/rcupdate.h>
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#include <linux/capability.h>
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#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/vermagic.h>
#include <linux/notifier.h>
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#include <linux/sched.h>
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#include <linux/stop_machine.h>
#include <linux/device.h>
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#include <linux/string.h>
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#include <linux/mutex.h>
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#include <linux/rculist.h>
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#include <asm/uaccess.h>
#include <asm/cacheflush.h>
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#include <linux/license.h>
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#include <asm/sections.h>
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#include <linux/tracepoint.h>
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#include <linux/ftrace.h>
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#include <linux/async.h>
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#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))

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/* List of modules, protected by module_mutex or preempt_disable
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 * (delete uses stop_machine/add uses RCU list operations). */
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static DEFINE_MUTEX(module_mutex);
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static LIST_HEAD(modules);

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/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);

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static BLOCKING_NOTIFIER_HEAD(module_notify_list);
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/* Bounds of module allocation, for speeding __module_text_address */
static unsigned long module_addr_min = -1UL, module_addr_max = 0;

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int register_module_notifier(struct notifier_block * nb)
{
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	return blocking_notifier_chain_register(&module_notify_list, nb);
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}
EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block * nb)
{
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	return blocking_notifier_chain_unregister(&module_notify_list, nb);
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}
EXPORT_SYMBOL(unregister_module_notifier);

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/* We require a truly strong try_module_get(): 0 means failure due to
   ongoing or failed initialization etc. */
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static inline int strong_try_module_get(struct module *mod)
{
	if (mod && mod->state == MODULE_STATE_COMING)
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		return -EBUSY;
	if (try_module_get(mod))
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		return 0;
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	else
		return -ENOENT;
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}

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static inline void add_taint_module(struct module *mod, unsigned flag)
{
	add_taint(flag);
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	mod->taints |= (1U << flag);
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}

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/*
 * A thread that wants to hold a reference to a module only while it
 * is running can call this to safely exit.  nfsd and lockd use this.
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 */
void __module_put_and_exit(struct module *mod, long code)
{
	module_put(mod);
	do_exit(code);
}
EXPORT_SYMBOL(__module_put_and_exit);
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/* 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;
}

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/* Find a module section, or NULL. */
static void *section_addr(Elf_Ehdr *hdr, Elf_Shdr *shdrs,
			  const char *secstrings, const char *name)
{
	/* Section 0 has sh_addr 0. */
	return (void *)shdrs[find_sec(hdr, shdrs, secstrings, name)].sh_addr;
}

/* Find a module section, or NULL.  Fill in number of "objects" in section. */
static void *section_objs(Elf_Ehdr *hdr,
			  Elf_Shdr *sechdrs,
			  const char *secstrings,
			  const char *name,
			  size_t object_size,
			  unsigned int *num)
{
	unsigned int sec = find_sec(hdr, sechdrs, secstrings, name);

	/* Section 0 has sh_addr 0 and sh_size 0. */
	*num = sechdrs[sec].sh_size / object_size;
	return (void *)sechdrs[sec].sh_addr;
}

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/* 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[];
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extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
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extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
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extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
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extern const unsigned long __start___kcrctab_gpl_future[];
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#ifdef CONFIG_UNUSED_SYMBOLS
extern const struct kernel_symbol __start___ksymtab_unused[];
extern const struct kernel_symbol __stop___ksymtab_unused[];
extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
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extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
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#endif
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#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
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#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
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#endif

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struct symsearch {
	const struct kernel_symbol *start, *stop;
	const unsigned long *crcs;
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	enum {
		NOT_GPL_ONLY,
		GPL_ONLY,
		WILL_BE_GPL_ONLY,
	} licence;
	bool unused;
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};

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static bool each_symbol_in_section(const struct symsearch *arr,
				   unsigned int arrsize,
				   struct module *owner,
				   bool (*fn)(const struct symsearch *syms,
					      struct module *owner,
					      unsigned int symnum, void *data),
				   void *data)
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{
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	unsigned int i, j;
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	for (j = 0; j < arrsize; j++) {
		for (i = 0; i < arr[j].stop - arr[j].start; i++)
			if (fn(&arr[j], owner, i, data))
				return true;
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	}
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	return false;
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}

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/* Returns true as soon as fn returns true, otherwise false. */
static bool each_symbol(bool (*fn)(const struct symsearch *arr,
				   struct module *owner,
				   unsigned int symnum, void *data),
			void *data)
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{
	struct module *mod;
	const struct symsearch arr[] = {
		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
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		  NOT_GPL_ONLY, false },
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		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
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		  __start___kcrctab_gpl,
		  GPL_ONLY, false },
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		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
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		  __start___kcrctab_gpl_future,
		  WILL_BE_GPL_ONLY, false },
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#ifdef CONFIG_UNUSED_SYMBOLS
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		{ __start___ksymtab_unused, __stop___ksymtab_unused,
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		  __start___kcrctab_unused,
		  NOT_GPL_ONLY, true },
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		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
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		  __start___kcrctab_unused_gpl,
		  GPL_ONLY, true },
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#endif
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	};
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	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
		return true;
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	list_for_each_entry_rcu(mod, &modules, list) {
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		struct symsearch arr[] = {
			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
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			  NOT_GPL_ONLY, false },
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			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
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			  mod->gpl_crcs,
			  GPL_ONLY, false },
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			{ mod->gpl_future_syms,
			  mod->gpl_future_syms + mod->num_gpl_future_syms,
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			  mod->gpl_future_crcs,
			  WILL_BE_GPL_ONLY, false },
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#ifdef CONFIG_UNUSED_SYMBOLS
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			{ mod->unused_syms,
			  mod->unused_syms + mod->num_unused_syms,
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			  mod->unused_crcs,
			  NOT_GPL_ONLY, true },
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			{ mod->unused_gpl_syms,
			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,
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			  mod->unused_gpl_crcs,
			  GPL_ONLY, true },
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#endif
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		};

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		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
			return true;
	}
	return false;
}

struct find_symbol_arg {
	/* Input */
	const char *name;
	bool gplok;
	bool warn;

	/* Output */
	struct module *owner;
	const unsigned long *crc;
	unsigned long value;
};

static bool find_symbol_in_section(const struct symsearch *syms,
				   struct module *owner,
				   unsigned int symnum, void *data)
{
	struct find_symbol_arg *fsa = data;

	if (strcmp(syms->start[symnum].name, fsa->name) != 0)
		return false;

	if (!fsa->gplok) {
		if (syms->licence == GPL_ONLY)
			return false;
		if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
			printk(KERN_WARNING "Symbol %s is being used "
			       "by a non-GPL module, which will not "
			       "be allowed in the future\n", fsa->name);
			printk(KERN_WARNING "Please see the file "
			       "Documentation/feature-removal-schedule.txt "
			       "in the kernel source tree for more details.\n");
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		}
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	}
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#ifdef CONFIG_UNUSED_SYMBOLS
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	if (syms->unused && fsa->warn) {
		printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
		       "however this module is using it.\n", fsa->name);
		printk(KERN_WARNING
		       "This symbol will go away in the future.\n");
		printk(KERN_WARNING
		       "Please evalute if this is the right api to use and if "
		       "it really is, submit a report the linux kernel "
		       "mailinglist together with submitting your code for "
		       "inclusion.\n");
	}
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#endif
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	fsa->owner = owner;
	fsa->crc = symversion(syms->crcs, symnum);
	fsa->value = syms->start[symnum].value;
	return true;
}

/* Find a symbol, return value, (optional) crc and (optional) module
 * which owns it */
static unsigned long find_symbol(const char *name,
				 struct module **owner,
				 const unsigned long **crc,
				 bool gplok,
				 bool warn)
{
	struct find_symbol_arg fsa;

	fsa.name = name;
	fsa.gplok = gplok;
	fsa.warn = warn;

	if (each_symbol(find_symbol_in_section, &fsa)) {
		if (owner)
			*owner = fsa.owner;
		if (crc)
			*crc = fsa.crc;
		return fsa.value;
	}

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	DEBUGP("Failed to find symbol %s\n", name);
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	return -ENOENT;
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}

/* 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) {
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		int *new;

		new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2,
			       GFP_KERNEL);
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		if (!new)
			return 0;

		pcpu_num_allocated *= 2;
		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;
}

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static void *percpu_modalloc(unsigned long size, unsigned long align,
			     const char *name)
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{
	unsigned long extra;
	unsigned int i;
	void *ptr;

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

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static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
{
	int cpu;

	for_each_possible_cpu(cpu)
		memcpy(pcpudest + per_cpu_offset(cpu), from, size);
}

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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). */
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	pcpu_size[0] = -(__per_cpu_end-__per_cpu_start);
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	/* 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.\n");
		pcpu_num_used = 1;
	}

	return 0;
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}
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__initcall(percpu_modinit);
#else /* ... !CONFIG_SMP */
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static inline void *percpu_modalloc(unsigned long size, unsigned long align,
				    const char *name)
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{
	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 */

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#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\n", mod->field);                   \
}                                                                     \
static int modinfo_##field##_exists(struct module *mod)               \
{                                                                     \
	return mod->field != NULL;                                    \
}                                                                     \
static void free_modinfo_##field(struct module *mod)                  \
{                                                                     \
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	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
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}                                                                     \
static struct module_attribute modinfo_##field = {                    \
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	.attr = { .name = __stringify(field), .mode = 0444 },         \
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	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

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static char last_unloaded_module[MODULE_NAME_LEN+1];

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#ifdef CONFIG_MODULE_UNLOAD
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/* Init the unload section of the module. */
static void module_unload_init(struct module *mod)
{
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	int cpu;
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	INIT_LIST_HEAD(&mod->modules_which_use_me);
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	for_each_possible_cpu(cpu)
		local_set(__module_ref_addr(mod, cpu), 0);
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	/* Hold reference count during initialization. */
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	local_set(__module_ref_addr(mod, raw_smp_processor_id()), 1);
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	/* 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!\n", a->name, b->name);
			return 1;
		}
	}
	DEBUGP("%s does not use %s!\n", a->name, b->name);
	return 0;
}

/* Module a uses b */
static int use_module(struct module *a, struct module *b)
{
	struct module_use *use;
613
	int no_warn, err;
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	if (b == NULL || already_uses(a, b)) return 1;

617 618 619 620 621 622 623 624 625 626 627
	/* If we're interrupted or time out, we fail. */
	if (wait_event_interruptible_timeout(
		    module_wq, (err = strong_try_module_get(b)) != -EBUSY,
		    30 * HZ) <= 0) {
		printk("%s: gave up waiting for init of module %s.\n",
		       a->name, b->name);
		return 0;
	}

	/* If strong_try_module_get() returned a different error, we fail. */
	if (err)
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		return 0;

	DEBUGP("Allocating new usage for %s.\n", a->name);
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
		printk("%s: out of memory loading\n", a->name);
		module_put(b);
		return 0;
	}

	use->module_which_uses = a;
	list_add(&use->list, &b->modules_which_use_me);
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	no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
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	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\n", mod->name, i->name);
				module_put(i);
				list_del(&use->list);
				kfree(use);
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				sysfs_remove_link(i->holders_dir, mod->name);
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				/* There can be at most one match. */
				break;
			}
		}
	}
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
667
static inline int try_force_unload(unsigned int flags)
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{
	int ret = (flags & O_TRUNC);
	if (ret)
671
		add_taint(TAINT_FORCED_RMMOD);
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	return ret;
}
#else
675
static inline int try_force_unload(unsigned int flags)
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{
	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;

693 694
	/* If it's not unused, quit unless we're forcing. */
	if (module_refcount(sref->mod) != 0) {
695
		if (!(*sref->forced = try_force_unload(sref->flags)))
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			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)
{
706 707
	if (flags & O_NONBLOCK) {
		struct stopref sref = { mod, flags, forced };
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709
		return stop_machine(__try_stop_module, &sref, NULL);
710 711 712 713 714 715
	} else {
		/* We don't need to stop the machine for this. */
		mod->state = MODULE_STATE_GOING;
		synchronize_sched();
		return 0;
	}
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}

unsigned int module_refcount(struct module *mod)
{
720 721
	unsigned int total = 0;
	int cpu;
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723 724
	for_each_possible_cpu(cpu)
		total += local_read(__module_ref_addr(mod, cpu));
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	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)
{
734
	/* Since we might sleep for some time, release the mutex first */
735
	mutex_unlock(&module_mutex);
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	for (;;) {
		DEBUGP("Looking at refcount...\n");
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (module_refcount(mod) == 0)
			break;
		schedule();
	}
	current->state = TASK_RUNNING;
744
	mutex_lock(&module_mutex);
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}

747 748
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
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{
	struct module *mod;
751
	char name[MODULE_NAME_LEN];
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	int ret, forced = 0;

754 755 756 757 758 759 760
	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';

761 762 763 764 765 766 767 768 769 770
	/* Create stop_machine threads since free_module relies on
	 * a non-failing stop_machine call. */
	ret = stop_machine_create();
	if (ret)
		return ret;

	if (mutex_lock_interruptible(&module_mutex) != 0) {
		ret = -EINTR;
		goto out_stop;
	}
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	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\n", mod->name);
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
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	if (mod->init && !mod->exit) {
795
		forced = try_force_unload(flags);
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		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);

815
	mutex_unlock(&module_mutex);
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	/* Final destruction now noone is using it. */
817
	if (mod->exit != NULL)
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		mod->exit();
819 820
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
821
	async_synchronize_full();
822
	mutex_lock(&module_mutex);
823
	/* Store the name of the last unloaded module for diagnostic purposes */
824
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
825
	unregister_dynamic_debug_module(mod->name);
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	free_module(mod);

 out:
829
	mutex_unlock(&module_mutex);
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out_stop:
	stop_machine_destroy();
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	return ret;
}

835
static inline void print_unload_info(struct seq_file *m, struct module *mod)
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{
	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->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;

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	preempt_disable();
863
	if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false)))
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		BUG();
	module_put(owner);
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	preempt_enable();
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}
EXPORT_SYMBOL(__symbol_put);

void symbol_put_addr(void *addr)
{
872
	struct module *modaddr;
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874 875
	if (core_kernel_text((unsigned long)addr))
		return;
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877 878 879
	if (!(modaddr = module_text_address((unsigned long)addr)))
		BUG();
	module_put(modaddr);
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}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
			   struct module *mod, char *buffer)
{
886
	return sprintf(buffer, "%u\n", module_refcount(mod));
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}

static struct module_attribute refcnt = {
890
	.attr = { .name = "refcnt", .mode = 0444 },
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	.show = show_refcnt,
};

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void module_put(struct module *module)
{
	if (module) {
		unsigned int cpu = get_cpu();
898
		local_dec(__module_ref_addr(module, cpu));
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		/* Maybe they're waiting for us to drop reference? */
		if (unlikely(!module_is_live(module)))
			wake_up_process(module->waiter);
		put_cpu();
	}
}
EXPORT_SYMBOL(module_put);

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#else /* !CONFIG_MODULE_UNLOAD */
908
static inline void print_unload_info(struct seq_file *m, struct module *mod)
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{
	/* 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)
{
920
	return strong_try_module_get(b) == 0;
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}

static inline void module_unload_init(struct module *mod)
{
}
#endif /* CONFIG_MODULE_UNLOAD */

928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947
static ssize_t show_initstate(struct module_attribute *mattr,
			   struct module *mod, char *buffer)
{
	const char *state = "unknown";

	switch (mod->state) {
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
	}
	return sprintf(buffer, "%s\n", state);
}

static struct module_attribute initstate = {
948
	.attr = { .name = "initstate", .mode = 0444 },
949 950 951
	.show = show_initstate,
};

952 953 954
static struct module_attribute *modinfo_attrs[] = {
	&modinfo_version,
	&modinfo_srcversion,
955
	&initstate,
956 957 958 959 960 961
#ifdef CONFIG_MODULE_UNLOAD
	&refcnt,
#endif
	NULL,
};

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static const char vermagic[] = VERMAGIC_STRING;

964 965 966
static int try_to_force_load(struct module *mod, const char *symname)
{
#ifdef CONFIG_MODULE_FORCE_LOAD
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	if (!test_taint(TAINT_FORCED_MODULE))
968 969 970 971 972 973 974 975 976
		printk("%s: no version for \"%s\" found: kernel tainted.\n",
		       mod->name, symname);
	add_taint_module(mod, TAINT_FORCED_MODULE);
	return 0;
#else
	return -ENOEXEC;
#endif
}

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#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;

991 992 993 994
	/* No versions at all?  modprobe --force does this. */
	if (versindex == 0)
		return try_to_force_load(mod, symname) == 0;

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	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;
		DEBUGP("Found checksum %lX vs module %lX\n",
		       *crc, versions[i].crc);
1007
		goto bad_version;
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	}
1009

1010 1011 1012
	printk(KERN_WARNING "%s: no symbol version for %s\n",
	       mod->name, symname);
	return 0;
1013 1014 1015 1016 1017

bad_version:
	printk("%s: disagrees about version of symbol %s\n",
	       mod->name, symname);
	return 0;
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}

static inline int check_modstruct_version(Elf_Shdr *sechdrs,
					  unsigned int versindex,
					  struct module *mod)
{
	const unsigned long *crc;

1026
	if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
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		BUG();
1028
	return check_version(sechdrs, versindex, "struct_module", mod, crc);
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}

1031 1032 1033
/* First part is kernel version, which we ignore if module has crcs. */
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
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{
1035 1036 1037 1038
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
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	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;
}

1058 1059
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
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{
	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;

1076
	ret = find_symbol(name, &owner, &crc,
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Andi Kleen 已提交
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			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1078
	if (!IS_ERR_VALUE(ret)) {
1079 1080
		/* use_module can fail due to OOM,
		   or module initialization or unloading */
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		if (!check_version(sechdrs, versindex, name, mod, crc) ||
		    !use_module(mod, owner))
1083
			ret = -EINVAL;
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	}
	return ret;
}

/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
1092
#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106
struct module_sect_attr
{
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

struct module_sect_attrs
{
	struct attribute_group grp;
	unsigned int nsections;
	struct module_sect_attr attrs[0];
};

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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\n", sattr->address);
}

1115 1116
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1117
	unsigned int section;
1118 1119 1120 1121 1122 1123

	for (section = 0; section < sect_attrs->nsections; section++)
		kfree(sect_attrs->attrs[section].name);
	kfree(sect_attrs);
}

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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;
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	/* 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]);
1140 1141
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
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		return;

	/* Setup section attributes. */
	sect_attrs->grp.name = "sections";
	sect_attrs->grp.attrs = (void *)sect_attrs + size[0];

1148
	sect_attrs->nsections = 0;
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	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;
1155 1156 1157 1158 1159
		sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
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		sattr->mattr.show = module_sect_show;
		sattr->mattr.store = NULL;
		sattr->mattr.attr.name = sattr->name;
		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:
1174
	free_sect_attrs(sect_attrs);
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}

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. */
1184
		free_sect_attrs(mod->sect_attrs);
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		mod->sect_attrs = NULL;
	}
}

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/*
 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
 */

struct module_notes_attrs {
	struct kobject *dir;
	unsigned int notes;
	struct bin_attribute attrs[0];
};

static ssize_t module_notes_read(struct kobject *kobj,
				 struct bin_attribute *bin_attr,
				 char *buf, loff_t pos, size_t count)
{
	/*
	 * The caller checked the pos and count against our size.
	 */
	memcpy(buf, bin_attr->private + pos, count);
	return count;
}

static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
			     unsigned int i)
{
	if (notes_attrs->dir) {
		while (i-- > 0)
			sysfs_remove_bin_file(notes_attrs->dir,
					      &notes_attrs->attrs[i]);
1217
		kobject_put(notes_attrs->dir);
R
Roland McGrath 已提交
1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260
	}
	kfree(notes_attrs);
}

static void add_notes_attrs(struct module *mod, unsigned int nsect,
			    char *secstrings, Elf_Shdr *sechdrs)
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

	/* Count notes sections and allocate structures.  */
	notes = 0;
	for (i = 0; i < nsect; i++)
		if ((sechdrs[i].sh_flags & SHF_ALLOC) &&
		    (sechdrs[i].sh_type == SHT_NOTE))
			++notes;

	if (notes == 0)
		return;

	notes_attrs = kzalloc(sizeof(*notes_attrs)
			      + notes * sizeof(notes_attrs->attrs[0]),
			      GFP_KERNEL);
	if (notes_attrs == NULL)
		return;

	notes_attrs->notes = notes;
	nattr = &notes_attrs->attrs[0];
	for (loaded = i = 0; i < nsect; ++i) {
		if (!(sechdrs[i].sh_flags & SHF_ALLOC))
			continue;
		if (sechdrs[i].sh_type == SHT_NOTE) {
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
			nattr->size = sechdrs[i].sh_size;
			nattr->private = (void *) sechdrs[i].sh_addr;
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1261
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
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1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
	if (!notes_attrs->dir)
		goto out;

	for (i = 0; i < notes; ++i)
		if (sysfs_create_bin_file(notes_attrs->dir,
					  &notes_attrs->attrs[i]))
			goto out;

	mod->notes_attrs = notes_attrs;
	return;

  out:
	free_notes_attrs(notes_attrs, i);
}

static void remove_notes_attrs(struct module *mod)
{
	if (mod->notes_attrs)
		free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
}

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1283
#else
1284

L
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1285 1286 1287 1288 1289 1290 1291 1292
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)
{
}
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static inline void add_notes_attrs(struct module *mod, unsigned int nsect,
				   char *sectstrings, Elf_Shdr *sechdrs)
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
1302
#endif
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1304 1305
#ifdef CONFIG_SYSFS
int module_add_modinfo_attrs(struct module *mod)
1306 1307
{
	struct module_attribute *attr;
1308
	struct module_attribute *temp_attr;
1309 1310 1311
	int error = 0;
	int i;

1312 1313 1314 1315 1316 1317 1318
	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;
1319 1320
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1321 1322 1323 1324 1325
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
			++temp_attr;
		}
1326 1327 1328 1329
	}
	return error;
}

1330
void module_remove_modinfo_attrs(struct module *mod)
1331 1332 1333 1334
{
	struct module_attribute *attr;
	int i;

1335 1336 1337 1338
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1339
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1340 1341
		if (attr->free)
			attr->free(mod);
1342
	}
1343
	kfree(mod->modinfo_attrs);
1344
}
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1345

1346
int mod_sysfs_init(struct module *mod)
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1347 1348
{
	int err;
1349
	struct kobject *kobj;
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1351 1352
	if (!module_sysfs_initialized) {
		printk(KERN_ERR "%s: module sysfs not initialized\n",
1353 1354 1355 1356
		       mod->name);
		err = -EINVAL;
		goto out;
	}
1357 1358 1359 1360 1361 1362 1363 1364 1365

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
		printk(KERN_ERR "%s: module is already loaded\n", mod->name);
		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

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	mod->mkobj.mod = mod;
1367

1368 1369 1370 1371 1372 1373
	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
	mod->mkobj.kobj.kset = module_kset;
	err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
				   "%s", mod->name);
	if (err)
		kobject_put(&mod->mkobj.kobj);
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1375
	/* delay uevent until full sysfs population */
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out:
	return err;
}

1380
int mod_sysfs_setup(struct module *mod,
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			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1386
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1387 1388
	if (!mod->holders_dir) {
		err = -ENOMEM;
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		goto out_unreg;
1390
	}
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L
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	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
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		goto out_unreg_holders;
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1396 1397
	err = module_add_modinfo_attrs(mod);
	if (err)
1398
		goto out_unreg_param;
1399

1400
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
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1401 1402
	return 0;

1403 1404
out_unreg_param:
	module_param_sysfs_remove(mod);
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out_unreg_holders:
1406
	kobject_put(mod->holders_dir);
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out_unreg:
1408
	kobject_put(&mod->mkobj.kobj);
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	return err;
}
1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423

static void mod_sysfs_fini(struct module *mod)
{
	kobject_put(&mod->mkobj.kobj);
}

#else /* CONFIG_SYSFS */

static void mod_sysfs_fini(struct module *mod)
{
}

#endif /* CONFIG_SYSFS */
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static void mod_kobject_remove(struct module *mod)
{
1427
	module_remove_modinfo_attrs(mod);
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	module_param_sysfs_remove(mod);
1429 1430
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1431
	mod_sysfs_fini(mod);
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}

/*
 * 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;
}

1445
/* Free a module, remove from lists, etc (must hold module_mutex). */
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static void free_module(struct module *mod)
{
	/* Delete from various lists */
1449
	stop_machine(__unlink_module, mod, NULL);
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Roland McGrath 已提交
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	remove_notes_attrs(mod);
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	remove_sect_attrs(mod);
	mod_kobject_remove(mod);

	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

	/* Module unload stuff */
	module_unload_free(mod);

1460 1461 1462
	/* release any pointers to mcount in this module */
	ftrace_release(mod->module_core, mod->core_size);

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	/* This may be NULL, but that's OK */
	module_free(mod, mod->module_init);
	kfree(mod->args);
	if (mod->percpu)
		percpu_modfree(mod->percpu);
1468 1469 1470 1471
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
	if (mod->refptr)
		percpu_modfree(mod->refptr);
#endif
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	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

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	/* Finally, free the core (containing the module structure) */
	module_free(mod, mod->module_core);
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
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	unsigned long value;
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1483

R
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	preempt_disable();
1485
	value = find_symbol(symbol, &owner, NULL, true, true);
1486 1487 1488
	if (IS_ERR_VALUE(value))
		value = 0;
	else if (strong_try_module_get(owner))
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		value = 0;
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Rusty Russell 已提交
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	preempt_enable();
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	return (void *)value;
}
EXPORT_SYMBOL_GPL(__symbol_get);

1496 1497
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1498
 * in the kernel or in some other module's exported symbol table.
1499 1500 1501
 */
static int verify_export_symbols(struct module *mod)
{
1502
	unsigned int i;
1503
	struct module *owner;
1504 1505 1506 1507 1508 1509 1510 1511
	const struct kernel_symbol *s;
	struct {
		const struct kernel_symbol *sym;
		unsigned int num;
	} arr[] = {
		{ mod->syms, mod->num_syms },
		{ mod->gpl_syms, mod->num_gpl_syms },
		{ mod->gpl_future_syms, mod->num_gpl_future_syms },
1512
#ifdef CONFIG_UNUSED_SYMBOLS
1513 1514
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1515
#endif
1516
	};
1517

1518 1519 1520 1521 1522 1523 1524 1525 1526 1527
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
			if (!IS_ERR_VALUE(find_symbol(s->name, &owner,
						      NULL, true, false))) {
				printk(KERN_ERR
				       "%s: exports duplicate symbol %s"
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
1528
		}
1529 1530
	}
	return 0;
1531 1532
}

1533
/* Change all symbols so that st_value encodes the pointer directly. */
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Linus Torvalds 已提交
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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\n", strtab + sym[i].st_name);
			printk("%s: please compile with -fno-common\n",
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
			DEBUGP("Absolute symbol: 0x%08lx\n",
			       (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.  */
1569
			if (!IS_ERR_VALUE(sym[i].st_value))
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1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593
				break;
			/* Ok if weak.  */
			if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
				break;

			printk(KERN_WARNING "%s: Unknown symbol %s\n",
			       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;
}

1594 1595 1596 1597 1598 1599 1600 1601
/* 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;
}

L
Linus Torvalds 已提交
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/* Update size with this section: return offset. */
1603 1604
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
1605 1606 1607
{
	long ret;

1608
	*size += arch_mod_section_prepend(mod, section);
L
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1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647
	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:\n");
	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;
1648
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
L
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1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665
			DEBUGP("\t%s\n", secstrings + s->sh_name);
		}
		if (m == 0)
			mod->core_text_size = mod->core_size;
	}

	DEBUGP("Init section allocation order:\n");
	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;
1666
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
L
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1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
					 | INIT_OFFSET_MASK);
			DEBUGP("\t%s\n", secstrings + s->sh_name);
		}
		if (m == 0)
			mod->init_text_size = mod->init_size;
	}
}

static void set_license(struct module *mod, const char *license)
{
	if (!license)
		license = "unspecified";

1680
	if (!license_is_gpl_compatible(license)) {
A
Andi Kleen 已提交
1681
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
1682
			printk(KERN_WARNING "%s: module license '%s' taints "
1683 1684
				"kernel.\n", mod->name, license);
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
L
Linus Torvalds 已提交
1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721
	}
}

/* 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;
}

1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736
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));
	}
}

L
Linus Torvalds 已提交
1737
#ifdef CONFIG_KALLSYMS
1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750

/* 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;
}

1751 1752
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
1753
{
1754 1755 1756
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
1757
	else
1758 1759
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829
}

/* 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 */

R
Rusty Russell 已提交
1830
static void dynamic_printk_setup(struct mod_debug *debug, unsigned int num)
1831
{
R
Rusty Russell 已提交
1832 1833
#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG
	unsigned int i;
1834

R
Rusty Russell 已提交
1835 1836 1837 1838 1839 1840
	for (i = 0; i < num; i++) {
		register_dynamic_debug_module(debug[i].modname,
					      debug[i].type,
					      debug[i].logical_modname,
					      debug[i].flag_names,
					      debug[i].hash, debug[i].hash2);
1841 1842
	}
#endif /* CONFIG_DYNAMIC_PRINTK_DEBUG */
R
Rusty Russell 已提交
1843
}
1844

1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858
static void *module_alloc_update_bounds(unsigned long size)
{
	void *ret = module_alloc(size);

	if (ret) {
		/* Update module bounds. */
		if ((unsigned long)ret < module_addr_min)
			module_addr_min = (unsigned long)ret;
		if ((unsigned long)ret + size > module_addr_max)
			module_addr_max = (unsigned long)ret + size;
	}
	return ret;
}

L
Linus Torvalds 已提交
1859 1860
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
1861
static noinline struct module *load_module(void __user *umod,
L
Linus Torvalds 已提交
1862 1863 1864 1865 1866 1867
				  unsigned long len,
				  const char __user *uargs)
{
	Elf_Ehdr *hdr;
	Elf_Shdr *sechdrs;
	char *secstrings, *args, *modmagic, *strtab = NULL;
1868
	char *staging;
A
Andrew Morton 已提交
1869 1870 1871
	unsigned int i;
	unsigned int symindex = 0;
	unsigned int strindex = 0;
R
Rusty Russell 已提交
1872 1873 1874
	unsigned int modindex, versindex, infoindex, pcpuindex;
	unsigned int num_kp, num_mcount;
	struct kernel_param *kp;
L
Linus Torvalds 已提交
1875 1876 1877
	struct module *mod;
	long err = 0;
	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
R
Rusty Russell 已提交
1878
	unsigned long *mseg;
1879
	mm_segment_t old_fs;
L
Linus Torvalds 已提交
1880 1881 1882 1883 1884 1885 1886 1887 1888 1889

	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
	       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);
1890 1891 1892 1893 1894 1895 1896

	/* Create stop_machine threads since the error path relies on
	 * a non-failing stop_machine call. */
	err = stop_machine_create();
	if (err)
		goto free_hdr;

L
Linus Torvalds 已提交
1897 1898 1899 1900 1901 1902 1903
	if (copy_from_user(hdr, umod, len) != 0) {
		err = -EFAULT;
		goto free_hdr;
	}

	/* Sanity checks against insmoding binaries or wrong arch,
           weird elf version */
1904
	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
L
Linus Torvalds 已提交
1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948
	    || 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\n");
		err = -ENOEXEC;
		goto free_hdr;
	}
R
Rusty Russell 已提交
1949
	/* This is temporary: point mod into copy of data. */
L
Linus Torvalds 已提交
1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962
	mod = (void *)sechdrs[modindex].sh_addr;

	if (symindex == 0) {
		printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
		       mod->name);
		err = -ENOEXEC;
		goto free_hdr;
	}

	versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
	infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
	pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);

1963
	/* Don't keep modinfo and version sections. */
L
Linus Torvalds 已提交
1964
	sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1965
	sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
L
Linus Torvalds 已提交
1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980
#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) {
1981 1982 1983
		err = try_to_force_load(mod, "magic");
		if (err)
			goto free_hdr;
1984
	} else if (!same_magic(modmagic, vermagic, versindex)) {
L
Linus Torvalds 已提交
1985 1986 1987 1988 1989 1990
		printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
		       mod->name, modmagic, vermagic);
		err = -ENOEXEC;
		goto free_hdr;
	}

1991 1992 1993 1994 1995 1996 1997 1998
	staging = get_modinfo(sechdrs, infoindex, "staging");
	if (staging) {
		add_taint_module(mod, TAINT_CRAP);
		printk(KERN_WARNING "%s: module is from the staging directory,"
		       " the quality is unknown, you have been warned.\n",
		       mod->name);
	}

L
Linus Torvalds 已提交
1999
	/* Now copy in args */
2000 2001 2002
	args = strndup_user(uargs, ~0UL >> 1);
	if (IS_ERR(args)) {
		err = PTR_ERR(args);
L
Linus Torvalds 已提交
2003 2004
		goto free_hdr;
	}
2005

L
Linus Torvalds 已提交
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
	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,
2021 2022
					 sechdrs[pcpuindex].sh_addralign,
					 mod->name);
L
Linus Torvalds 已提交
2023 2024
		if (!percpu) {
			err = -ENOMEM;
2025
			goto free_mod;
L
Linus Torvalds 已提交
2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036
		}
		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. */
2037
	ptr = module_alloc_update_bounds(mod->core_size);
L
Linus Torvalds 已提交
2038 2039 2040 2041 2042 2043 2044
	if (!ptr) {
		err = -ENOMEM;
		goto free_percpu;
	}
	memset(ptr, 0, mod->core_size);
	mod->module_core = ptr;

2045
	ptr = module_alloc_update_bounds(mod->init_size);
L
Linus Torvalds 已提交
2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076
	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:\n");
	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\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
	}
	/* Module has been moved. */
	mod = (void *)sechdrs[modindex].sh_addr;

2077 2078 2079 2080 2081 2082 2083 2084
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
	mod->refptr = percpu_modalloc(sizeof(local_t), __alignof__(local_t),
				      mod->name);
	if (!mod->refptr) {
		err = -ENOMEM;
		goto free_init;
	}
#endif
L
Linus Torvalds 已提交
2085 2086 2087
	/* Now we've moved module, initialize linked lists, etc. */
	module_unload_init(mod);

2088
	/* add kobject, so we can reference it. */
2089 2090
	err = mod_sysfs_init(mod);
	if (err)
2091
		goto free_unload;
K
Kay Sievers 已提交
2092

L
Linus Torvalds 已提交
2093 2094 2095
	/* Set up license info based on the info section */
	set_license(mod, get_modinfo(sechdrs, infoindex, "license"));

2096 2097 2098 2099 2100
	/*
	 * 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.
	 */
2101
	if (strcmp(mod->name, "ndiswrapper") == 0)
2102 2103 2104
		add_taint(TAINT_PROPRIETARY_MODULE);

	/* driverloader was caught wrongly pretending to be under GPL */
2105 2106
	if (strcmp(mod->name, "driverloader") == 0)
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2107

2108 2109 2110
	/* Set up MODINFO_ATTR fields */
	setup_modinfo(mod, sechdrs, infoindex);

L
Linus Torvalds 已提交
2111 2112 2113 2114 2115 2116
	/* 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;

R
Rusty Russell 已提交
2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
	kp = section_objs(hdr, sechdrs, secstrings, "__param", sizeof(*kp),
			  &num_kp);
	mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab",
				 sizeof(*mod->syms), &mod->num_syms);
	mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab");
	mod->gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl",
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
	mod->gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(hdr, sechdrs, secstrings,
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
	mod->gpl_future_crcs = section_addr(hdr, sechdrs, secstrings,
					    "__kcrctab_gpl_future");
L
Linus Torvalds 已提交
2134

2135
#ifdef CONFIG_UNUSED_SYMBOLS
R
Rusty Russell 已提交
2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158
	mod->unused_syms = section_objs(hdr, sechdrs, secstrings,
					"__ksymtab_unused",
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
	mod->unused_crcs = section_addr(hdr, sechdrs, secstrings,
					"__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(hdr, sechdrs, secstrings,
					    "__ksymtab_unused_gpl",
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
	mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings,
					    "__kcrctab_unused_gpl");
#endif

#ifdef CONFIG_MARKERS
	mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers",
				    sizeof(*mod->markers), &mod->num_markers);
#endif
#ifdef CONFIG_TRACEPOINTS
	mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
					"__tracepoints",
					sizeof(*mod->tracepoints),
					&mod->num_tracepoints);
2159
#endif
2160

L
Linus Torvalds 已提交
2161
#ifdef CONFIG_MODVERSIONS
R
Rusty Russell 已提交
2162 2163 2164
	if ((mod->num_syms && !mod->crcs)
	    || (mod->num_gpl_syms && !mod->gpl_crcs)
	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2165
#ifdef CONFIG_UNUSED_SYMBOLS
R
Rusty Russell 已提交
2166 2167
	    || (mod->num_unused_syms && !mod->unused_crcs)
	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2168 2169
#endif
		) {
2170 2171 2172 2173
		printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name);
		err = try_to_force_load(mod, "nocrc");
		if (err)
			goto cleanup;
L
Linus Torvalds 已提交
2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198
	}
#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;
	}

2199 2200 2201 2202 2203
        /* Find duplicate symbols */
	err = verify_export_symbols(mod);
	if (err < 0)
		goto cleanup;

L
Linus Torvalds 已提交
2204
  	/* Set up and sort exception table */
R
Rusty Russell 已提交
2205 2206 2207
	mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);
	sort_extable(mod->extable, mod->extable + mod->num_exentries);
L
Linus Torvalds 已提交
2208 2209 2210 2211 2212 2213 2214

	/* 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);

M
Mathieu Desnoyers 已提交
2215
	if (!mod->taints) {
R
Rusty Russell 已提交
2216 2217 2218 2219 2220 2221
		struct mod_debug *debug;
		unsigned int num_debug;

		debug = section_objs(hdr, sechdrs, secstrings, "__verbose",
				     sizeof(*debug), &num_debug);
		dynamic_printk_setup(debug, num_debug);
M
Mathieu Desnoyers 已提交
2222
	}
2223

2224
	/* sechdrs[0].sh_size is always zero */
R
Rusty Russell 已提交
2225 2226
	mseg = section_objs(hdr, sechdrs, secstrings, "__mcount_loc",
			    sizeof(*mseg), &num_mcount);
2227
	ftrace_init_module(mod, mseg, mseg + num_mcount);
2228

L
Linus Torvalds 已提交
2229 2230 2231 2232
	err = module_finalize(hdr, sechdrs, mod);
	if (err < 0)
		goto cleanup;

2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250
	/* 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);

L
Linus Torvalds 已提交
2251
	mod->args = args;
R
Rusty Russell 已提交
2252
	if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
R
Rusty Russell 已提交
2253 2254 2255
		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
		       mod->name);

2256
	/* Now sew it into the lists so we can get lockdep and oops
2257 2258 2259 2260 2261 2262 2263
	 * info during argument parsing.  Noone should access us, since
	 * strong_try_module_get() will fail.
	 * lockdep/oops can run asynchronous, so use the RCU list insertion
	 * function to insert in a way safe to concurrent readers.
	 * The mutex protects against concurrent writers.
	 */
	list_add_rcu(&mod->list, &modules);
2264

R
Rusty Russell 已提交
2265
	err = parse_args(mod->name, mod->args, kp, num_kp, NULL);
L
Linus Torvalds 已提交
2266
	if (err < 0)
2267
		goto unlink;
L
Linus Torvalds 已提交
2268

R
Rusty Russell 已提交
2269
	err = mod_sysfs_setup(mod, kp, num_kp);
L
Linus Torvalds 已提交
2270
	if (err < 0)
2271
		goto unlink;
L
Linus Torvalds 已提交
2272
	add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
R
Roland McGrath 已提交
2273
	add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
L
Linus Torvalds 已提交
2274 2275 2276 2277

	/* Get rid of temporary copy */
	vfree(hdr);

2278
	stop_machine_destroy();
L
Linus Torvalds 已提交
2279 2280 2281
	/* Done! */
	return mod;

2282
 unlink:
2283
	stop_machine(__unlink_module, mod, NULL);
L
Linus Torvalds 已提交
2284 2285
	module_arch_cleanup(mod);
 cleanup:
2286 2287
	kobject_del(&mod->mkobj.kobj);
	kobject_put(&mod->mkobj.kobj);
2288
	ftrace_release(mod->module_core, mod->core_size);
2289
 free_unload:
L
Linus Torvalds 已提交
2290
	module_unload_free(mod);
2291 2292 2293 2294
 free_init:
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
	percpu_modfree(mod->refptr);
#endif
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2295 2296 2297
	module_free(mod, mod->module_init);
 free_core:
	module_free(mod, mod->module_core);
2298
	/* mod will be freed with core. Don't access it beyond this line! */
L
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2299 2300 2301 2302 2303 2304 2305
 free_percpu:
	if (percpu)
		percpu_modfree(percpu);
 free_mod:
	kfree(args);
 free_hdr:
	vfree(hdr);
2306
	stop_machine_destroy();
2307
	return ERR_PTR(err);
L
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2308 2309 2310 2311 2312 2313 2314 2315

 truncated:
	printk(KERN_ERR "Module len %lu truncated\n", len);
	err = -ENOEXEC;
	goto free_hdr;
}

/* This is where the real work happens */
2316 2317
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
2318 2319 2320 2321 2322 2323 2324 2325 2326
{
	struct module *mod;
	int ret = 0;

	/* Must have permission */
	if (!capable(CAP_SYS_MODULE))
		return -EPERM;

	/* Only one module load at a time, please */
2327
	if (mutex_lock_interruptible(&module_mutex) != 0)
L
Linus Torvalds 已提交
2328 2329 2330 2331 2332
		return -EINTR;

	/* Do all the hard work */
	mod = load_module(umod, len, uargs);
	if (IS_ERR(mod)) {
2333
		mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2334 2335 2336 2337
		return PTR_ERR(mod);
	}

	/* Drop lock so they can recurse */
2338
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2339

2340 2341
	blocking_notifier_call_chain(&module_notify_list,
			MODULE_STATE_COMING, mod);
L
Linus Torvalds 已提交
2342 2343 2344

	/* Start the module */
	if (mod->init != NULL)
2345
		ret = do_one_initcall(mod->init);
L
Linus Torvalds 已提交
2346 2347 2348 2349
	if (ret < 0) {
		/* Init routine failed: abort.  Try to protect us from
                   buggy refcounters. */
		mod->state = MODULE_STATE_GOING;
2350
		synchronize_sched();
R
Rusty Russell 已提交
2351
		module_put(mod);
2352 2353
		blocking_notifier_call_chain(&module_notify_list,
					     MODULE_STATE_GOING, mod);
R
Rusty Russell 已提交
2354 2355 2356
		mutex_lock(&module_mutex);
		free_module(mod);
		mutex_unlock(&module_mutex);
2357
		wake_up(&module_wq);
L
Linus Torvalds 已提交
2358 2359
		return ret;
	}
2360 2361 2362 2363 2364 2365 2366 2367
	if (ret > 0) {
		printk(KERN_WARNING "%s: '%s'->init suspiciously returned %d, "
				    "it should follow 0/-E convention\n"
		       KERN_WARNING "%s: loading module anyway...\n",
		       __func__, mod->name, ret,
		       __func__);
		dump_stack();
	}
L
Linus Torvalds 已提交
2368

2369
	/* Now it's a first class citizen!  Wake up anyone waiting for it. */
L
Linus Torvalds 已提交
2370
	mod->state = MODULE_STATE_LIVE;
2371
	wake_up(&module_wq);
2372 2373
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_LIVE, mod);
2374 2375

	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
2376 2377 2378 2379 2380 2381
	/* 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;
2382
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398

	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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
D
Daniel Walker 已提交
2399
	return str[0] == '$' && strchr("atd", str[1])
L
Linus Torvalds 已提交
2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411
	       && (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 */
2412
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
2413
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
D
Daniel Walker 已提交
2414
	else
L
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2415 2416 2417
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

	/* Scan for closest preceeding symbol, and next symbol. (ELF
D
Daniel Walker 已提交
2418
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439
	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;

A
Alexey Dobriyan 已提交
2440 2441 2442 2443
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
2444 2445 2446
	return mod->strtab + mod->symtab[best].st_name;
}

2447 2448
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
2449
const char *module_address_lookup(unsigned long addr,
2450 2451 2452 2453
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
2454 2455
{
	struct module *mod;
2456
	const char *ret = NULL;
L
Linus Torvalds 已提交
2457

2458
	preempt_disable();
2459
	list_for_each_entry_rcu(mod, &modules, list) {
2460 2461
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
2462 2463
			if (modname)
				*modname = mod->name;
2464 2465
			ret = get_ksymbol(mod, addr, size, offset);
			break;
L
Linus Torvalds 已提交
2466 2467
		}
	}
2468 2469 2470 2471 2472
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
2473
	preempt_enable();
2474
	return ret;
L
Linus Torvalds 已提交
2475 2476
}

2477 2478 2479 2480
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

2481
	preempt_disable();
2482
	list_for_each_entry_rcu(mod, &modules, list) {
2483 2484
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
2485 2486 2487 2488 2489
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
2490
			strlcpy(symname, sym, KSYM_NAME_LEN);
2491
			preempt_enable();
2492 2493 2494 2495
			return 0;
		}
	}
out:
2496
	preempt_enable();
2497 2498 2499
	return -ERANGE;
}

2500 2501 2502 2503 2504
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

2505
	preempt_disable();
2506
	list_for_each_entry_rcu(mod, &modules, list) {
2507 2508
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
2509 2510 2511 2512 2513 2514
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
2515
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
2516
			if (name)
2517
				strlcpy(name, sym, KSYM_NAME_LEN);
2518
			preempt_enable();
2519 2520 2521 2522
			return 0;
		}
	}
out:
2523
	preempt_enable();
2524 2525 2526
	return -ERANGE;
}

2527 2528
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
			char *name, char *module_name, int *exported)
L
Linus Torvalds 已提交
2529 2530 2531
{
	struct module *mod;

2532
	preempt_disable();
2533
	list_for_each_entry_rcu(mod, &modules, list) {
L
Linus Torvalds 已提交
2534 2535 2536
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
2537
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2538 2539
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
2540
			*exported = is_exported(name, *value, mod);
2541
			preempt_enable();
2542
			return 0;
L
Linus Torvalds 已提交
2543 2544 2545
		}
		symnum -= mod->num_symtab;
	}
2546
	preempt_enable();
2547
	return -ERANGE;
L
Linus Torvalds 已提交
2548 2549 2550 2551 2552 2553 2554
}

static unsigned long mod_find_symname(struct module *mod, const char *name)
{
	unsigned int i;

	for (i = 0; i < mod->num_symtab; i++)
2555 2556
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568
			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. */
2569
	preempt_disable();
L
Linus Torvalds 已提交
2570 2571 2572 2573 2574 2575
	if ((colon = strchr(name, ':')) != NULL) {
		*colon = '\0';
		if ((mod = find_module(name)) != NULL)
			ret = mod_find_symname(mod, colon+1);
		*colon = ':';
	} else {
2576
		list_for_each_entry_rcu(mod, &modules, list)
L
Linus Torvalds 已提交
2577 2578 2579
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
	}
2580
	preempt_enable();
L
Linus Torvalds 已提交
2581 2582 2583 2584
	return ret;
}
#endif /* CONFIG_KALLSYMS */

2585
static char *module_flags(struct module *mod, char *buf)
2586 2587 2588
{
	int bx = 0;

2589 2590 2591
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
2592
		buf[bx++] = '(';
A
Andi Kleen 已提交
2593
		if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
2594
			buf[bx++] = 'P';
A
Andi Kleen 已提交
2595
		if (mod->taints & (1 << TAINT_FORCED_MODULE))
2596
			buf[bx++] = 'F';
2597
		if (mod->taints & (1 << TAINT_CRAP))
2598
			buf[bx++] = 'C';
2599 2600 2601 2602 2603
		/*
		 * TAINT_FORCED_RMMOD: could be added.
		 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
		 * apply to modules.
		 */
2604 2605 2606 2607 2608 2609 2610

		/* Show a - for module-is-being-unloaded */
		if (mod->state == MODULE_STATE_GOING)
			buf[bx++] = '-';
		/* Show a + for module-is-being-loaded */
		if (mod->state == MODULE_STATE_COMING)
			buf[bx++] = '+';
2611 2612 2613 2614 2615 2616 2617
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635
#ifdef CONFIG_PROC_FS
/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&module_mutex);
	return seq_list_start(&modules, *pos);
}

static void *m_next(struct seq_file *m, void *p, loff_t *pos)
{
	return seq_list_next(p, &modules, pos);
}

static void m_stop(struct seq_file *m, void *p)
{
	mutex_unlock(&module_mutex);
}

L
Linus Torvalds 已提交
2636 2637 2638
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
2639 2640
	char buf[8];

2641
	seq_printf(m, "%s %u",
L
Linus Torvalds 已提交
2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652
		   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);

2653 2654
	/* Taints info */
	if (mod->taints)
2655
		seq_printf(m, " %s", module_flags(mod, buf));
2656

L
Linus Torvalds 已提交
2657 2658 2659 2660 2661 2662 2663 2664 2665
	seq_printf(m, "\n");
	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
2666
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
2667 2668 2669 2670 2671 2672
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692
static int modules_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &modules_op);
}

static const struct file_operations proc_modules_operations = {
	.open		= modules_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

static int __init proc_modules_init(void)
{
	proc_create("modules", 0, NULL, &proc_modules_operations);
	return 0;
}
module_init(proc_modules_init);
#endif

L
Linus Torvalds 已提交
2693 2694 2695 2696 2697 2698
/* 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;

R
Rusty Russell 已提交
2699
	preempt_disable();
2700
	list_for_each_entry_rcu(mod, &modules, list) {
L
Linus Torvalds 已提交
2701 2702
		if (mod->num_exentries == 0)
			continue;
D
Daniel Walker 已提交
2703

L
Linus Torvalds 已提交
2704 2705 2706 2707 2708 2709
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
R
Rusty Russell 已提交
2710
	preempt_enable();
L
Linus Torvalds 已提交
2711 2712

	/* Now, if we found one, we are running inside it now, hence
D
Daniel Walker 已提交
2713
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
2714 2715 2716
	return e;
}

2717 2718 2719 2720 2721 2722 2723
/*
 * Is this a valid module address?
 */
int is_module_address(unsigned long addr)
{
	struct module *mod;

R
Rusty Russell 已提交
2724
	preempt_disable();
2725

2726
	list_for_each_entry_rcu(mod, &modules, list) {
2727
		if (within_module_core(addr, mod)) {
R
Rusty Russell 已提交
2728
			preempt_enable();
2729 2730 2731 2732
			return 1;
		}
	}

R
Rusty Russell 已提交
2733
	preempt_enable();
2734 2735 2736 2737 2738

	return 0;
}


R
Rusty Russell 已提交
2739
/* Is this a valid kernel address? */
2740
__notrace_funcgraph struct module *__module_text_address(unsigned long addr)
L
Linus Torvalds 已提交
2741 2742 2743
{
	struct module *mod;

2744 2745 2746
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

2747
	list_for_each_entry_rcu(mod, &modules, list)
L
Linus Torvalds 已提交
2748 2749 2750 2751 2752 2753 2754 2755 2756 2757
		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;

R
Rusty Russell 已提交
2758
	preempt_disable();
L
Linus Torvalds 已提交
2759
	mod = __module_text_address(addr);
R
Rusty Russell 已提交
2760
	preempt_enable();
L
Linus Torvalds 已提交
2761 2762 2763 2764 2765 2766 2767 2768

	return mod;
}

/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
2769
	char buf[8];
L
Linus Torvalds 已提交
2770 2771

	printk("Modules linked in:");
2772 2773 2774
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
	list_for_each_entry_rcu(mod, &modules, list)
2775
		printk(" %s%s", mod->name, module_flags(mod, buf));
2776
	preempt_enable();
2777 2778
	if (last_unloaded_module[0])
		printk(" [last unloaded: %s]", last_unloaded_module);
L
Linus Torvalds 已提交
2779 2780 2781 2782 2783 2784 2785 2786
	printk("\n");
}

#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
M
Mathieu Desnoyers 已提交
2787 2788

#ifdef CONFIG_MARKERS
2789
void module_update_markers(void)
M
Mathieu Desnoyers 已提交
2790 2791 2792 2793 2794 2795 2796
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry(mod, &modules, list)
		if (!mod->taints)
			marker_update_probe_range(mod->markers,
2797
				mod->markers + mod->num_markers);
M
Mathieu Desnoyers 已提交
2798 2799 2800
	mutex_unlock(&module_mutex);
}
#endif
M
Mathieu Desnoyers 已提交
2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847

#ifdef CONFIG_TRACEPOINTS
void module_update_tracepoints(void)
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry(mod, &modules, list)
		if (!mod->taints)
			tracepoint_update_probe_range(mod->tracepoints,
				mod->tracepoints + mod->num_tracepoints);
	mutex_unlock(&module_mutex);
}

/*
 * Returns 0 if current not found.
 * Returns 1 if current found.
 */
int module_get_iter_tracepoints(struct tracepoint_iter *iter)
{
	struct module *iter_mod;
	int found = 0;

	mutex_lock(&module_mutex);
	list_for_each_entry(iter_mod, &modules, list) {
		if (!iter_mod->taints) {
			/*
			 * Sorted module list
			 */
			if (iter_mod < iter->module)
				continue;
			else if (iter_mod > iter->module)
				iter->tracepoint = NULL;
			found = tracepoint_get_iter_range(&iter->tracepoint,
				iter_mod->tracepoints,
				iter_mod->tracepoints
					+ iter_mod->num_tracepoints);
			if (found) {
				iter->module = iter_mod;
				break;
			}
		}
	}
	mutex_unlock(&module_mutex);
	return found;
}
#endif