module.c 71.7 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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#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)
{
	unsigned int i;

	INIT_LIST_HEAD(&mod->modules_which_use_me);
	for (i = 0; i < NR_CPUS; i++)
		local_set(&mod->ref[i].count, 0);
	/* Hold reference count during initialization. */
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	local_set(&mod->ref[raw_smp_processor_id()].count, 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;
612
	int no_warn, err;
K
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	if (b == NULL || already_uses(a, b)) return 1;

616 617 618 619 620 621 622 623 624 625 626
	/* 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
666
static inline int try_force_unload(unsigned int flags)
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{
	int ret = (flags & O_TRUNC);
	if (ret)
670
		add_taint(TAINT_FORCED_RMMOD);
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	return ret;
}
#else
674
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;

692 693
	/* If it's not unused, quit unless we're forcing. */
	if (module_refcount(sref->mod) != 0) {
694
		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)
{
705 706
	if (flags & O_NONBLOCK) {
		struct stopref sref = { mod, flags, forced };
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708
		return stop_machine(__try_stop_module, &sref, NULL);
709 710 711 712 713 714
	} 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)
{
	unsigned int i, total = 0;

	for (i = 0; i < NR_CPUS; i++)
		total += local_read(&mod->ref[i].count);
	return total;
}
EXPORT_SYMBOL(module_refcount);

/* This exists whether we can unload or not */
static void free_module(struct module *mod);

static void wait_for_zero_refcount(struct module *mod)
{
732
	/* Since we might sleep for some time, release the mutex first */
733
	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;
742
	mutex_lock(&module_mutex);
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}

745 746
asmlinkage long
sys_delete_module(const char __user *name_user, unsigned int flags)
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{
	struct module *mod;
749
	char name[MODULE_NAME_LEN];
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	int ret, forced = 0;

752 753 754 755 756 757 758
	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';

759 760 761 762 763 764 765 766 767 768
	/* 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) {
793
		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);

813
	mutex_unlock(&module_mutex);
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	/* Final destruction now noone is using it. */
815
	if (mod->exit != NULL)
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		mod->exit();
817 818 819
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
	mutex_lock(&module_mutex);
820
	/* Store the name of the last unloaded module for diagnostic purposes */
821
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
822
	unregister_dynamic_debug_module(mod->name);
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	free_module(mod);

 out:
826
	mutex_unlock(&module_mutex);
827 828
out_stop:
	stop_machine_destroy();
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	return ret;
}

832
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;

R
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	preempt_disable();
860
	if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false)))
L
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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)
{
869
	struct module *modaddr;
L
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871 872
	if (core_kernel_text((unsigned long)addr))
		return;
L
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873

874 875 876
	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)
{
883
	return sprintf(buffer, "%u\n", module_refcount(mod));
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}

static struct module_attribute refcnt = {
887
	.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();
		local_dec(&module->ref[cpu].count);
		/* 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 */
905
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)
{
917
	return strong_try_module_get(b) == 0;
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}

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

925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944
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 = {
945
	.attr = { .name = "initstate", .mode = 0444 },
946 947 948
	.show = show_initstate,
};

949 950 951
static struct module_attribute *modinfo_attrs[] = {
	&modinfo_version,
	&modinfo_srcversion,
952
	&initstate,
953 954 955 956 957 958
#ifdef CONFIG_MODULE_UNLOAD
	&refcnt,
#endif
	NULL,
};

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static const char vermagic[] = VERMAGIC_STRING;

961 962 963
static int try_to_force_load(struct module *mod, const char *symname)
{
#ifdef CONFIG_MODULE_FORCE_LOAD
A
Andi Kleen 已提交
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	if (!test_taint(TAINT_FORCED_MODULE))
965 966 967 968 969 970 971 972 973
		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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974 975 976 977 978 979 980 981 982 983 984 985 986 987
#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;

988 989 990 991
	/* 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);
1004
		goto bad_version;
L
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1005
	}
1006

1007 1008 1009
	printk(KERN_WARNING "%s: no symbol version for %s\n",
	       mod->name, symname);
	return 0;
1010 1011 1012 1013 1014

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;

1023
	if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
L
Linus Torvalds 已提交
1024
		BUG();
1025
	return check_version(sechdrs, versindex, "struct_module", mod, crc);
L
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}

1028 1029 1030
/* 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)
L
Linus Torvalds 已提交
1031
{
1032 1033 1034 1035
	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;
}

1055 1056
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;

1073
	ret = find_symbol(name, &owner, &crc,
A
Andi Kleen 已提交
1074
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1075
	if (!IS_ERR_VALUE(ret)) {
1076 1077
		/* use_module can fail due to OOM,
		   or module initialization or unloading */
L
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		if (!check_version(sechdrs, versindex, name, mod, crc) ||
		    !use_module(mod, owner))
1080
			ret = -EINVAL;
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	}
	return ret;
}

/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
1089
#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103
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);
}

1112 1113
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1114
	unsigned int section;
1115 1116 1117 1118 1119 1120

	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;
D
Daniel Walker 已提交
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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]);
1137 1138
	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];

1145
	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;
1152 1153 1154 1155 1156
		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:
1171
	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. */
1181
		free_sect_attrs(mod->sect_attrs);
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		mod->sect_attrs = NULL;
	}
}

R
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1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
/*
 * /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]);
1214
		kobject_put(notes_attrs->dir);
R
Roland McGrath 已提交
1215 1216 1217 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
	}
	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;
	}

1258
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
R
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1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279
	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);
}

L
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1280
#else
1281

L
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1282 1283 1284 1285 1286 1287 1288 1289
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)
{
}
R
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1290 1291 1292 1293 1294 1295 1296 1297 1298

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)
{
}
1299
#endif
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1300

1301 1302
#ifdef CONFIG_SYSFS
int module_add_modinfo_attrs(struct module *mod)
1303 1304
{
	struct module_attribute *attr;
1305
	struct module_attribute *temp_attr;
1306 1307 1308
	int error = 0;
	int i;

1309 1310 1311 1312 1313 1314 1315
	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;
1316 1317
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1318 1319 1320 1321 1322
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
			++temp_attr;
		}
1323 1324 1325 1326
	}
	return error;
}

1327
void module_remove_modinfo_attrs(struct module *mod)
1328 1329 1330 1331
{
	struct module_attribute *attr;
	int i;

1332 1333 1334 1335
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1336
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1337 1338
		if (attr->free)
			attr->free(mod);
1339
	}
1340
	kfree(mod->modinfo_attrs);
1341
}
L
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1342

1343
int mod_sysfs_init(struct module *mod)
L
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1344 1345
{
	int err;
1346
	struct kobject *kobj;
L
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1347

1348 1349
	if (!module_sysfs_initialized) {
		printk(KERN_ERR "%s: module sysfs not initialized\n",
1350 1351 1352 1353
		       mod->name);
		err = -EINVAL;
		goto out;
	}
1354 1355 1356 1357 1358 1359 1360 1361 1362

	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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1363
	mod->mkobj.mod = mod;
1364

1365 1366 1367 1368 1369 1370
	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);
K
Kay Sievers 已提交
1371

1372
	/* delay uevent until full sysfs population */
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1373 1374 1375 1376
out:
	return err;
}

1377
int mod_sysfs_setup(struct module *mod,
K
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1378 1379 1380 1381 1382
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1383
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1384 1385
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1386
		goto out_unreg;
1387
	}
K
Kay Sievers 已提交
1388

L
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1389 1390
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1391
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1392

1393 1394
	err = module_add_modinfo_attrs(mod);
	if (err)
1395
		goto out_unreg_param;
1396

1397
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
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1398 1399
	return 0;

1400 1401
out_unreg_param:
	module_param_sysfs_remove(mod);
K
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1402
out_unreg_holders:
1403
	kobject_put(mod->holders_dir);
K
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1404
out_unreg:
1405
	kobject_put(&mod->mkobj.kobj);
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1406 1407
	return err;
}
1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420

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)
{
1424
	module_remove_modinfo_attrs(mod);
L
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1425
	module_param_sysfs_remove(mod);
1426 1427
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1428
	mod_sysfs_fini(mod);
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1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441
}

/*
 * 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;
}

1442
/* Free a module, remove from lists, etc (must hold module_mutex). */
L
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static void free_module(struct module *mod)
{
	/* Delete from various lists */
1446
	stop_machine(__unlink_module, mod, NULL);
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Roland McGrath 已提交
1447
	remove_notes_attrs(mod);
L
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1448 1449 1450 1451 1452 1453 1454 1455 1456
	remove_sect_attrs(mod);
	mod_kobject_remove(mod);

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

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

1457 1458 1459
	/* 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);

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Ingo Molnar 已提交
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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;
R
Rusty Russell 已提交
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	unsigned long value;
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1477

R
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	preempt_disable();
1479
	value = find_symbol(symbol, &owner, NULL, true, true);
1480 1481 1482
	if (IS_ERR_VALUE(value))
		value = 0;
	else if (strong_try_module_get(owner))
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		value = 0;
R
Rusty Russell 已提交
1484
	preempt_enable();
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1485 1486 1487 1488 1489

	return (void *)value;
}
EXPORT_SYMBOL_GPL(__symbol_get);

1490 1491
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1492
 * in the kernel or in some other module's exported symbol table.
1493 1494 1495
 */
static int verify_export_symbols(struct module *mod)
{
1496
	unsigned int i;
1497
	struct module *owner;
1498 1499 1500 1501 1502 1503 1504 1505
	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 },
1506
#ifdef CONFIG_UNUSED_SYMBOLS
1507 1508
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1509
#endif
1510
	};
1511

1512 1513 1514 1515 1516 1517 1518 1519 1520 1521
	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;
			}
1522
		}
1523 1524
	}
	return 0;
1525 1526
}

1527
/* Change all symbols so that st_value encodes the pointer directly. */
L
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.  */
1563
			if (!IS_ERR_VALUE(sym[i].st_value))
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1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587
				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;
}

1588 1589 1590 1591 1592 1593 1594 1595
/* 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
1596
/* Update size with this section: return offset. */
1597 1598
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
1599 1600 1601
{
	long ret;

1602
	*size += arch_mod_section_prepend(mod, section);
L
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1603 1604 1605 1606 1607 1608 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
	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;
1642
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
L
Linus Torvalds 已提交
1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659
			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;
1660
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
L
Linus Torvalds 已提交
1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673
					 | 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";

1674
	if (!license_is_gpl_compatible(license)) {
A
Andi Kleen 已提交
1675
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
1676
			printk(KERN_WARNING "%s: module license '%s' taints "
1677 1678
				"kernel.\n", mod->name, license);
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
L
Linus Torvalds 已提交
1679 1680 1681 1682 1683 1684 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
	}
}

/* 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;
}

1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730
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
1731
#ifdef CONFIG_KALLSYMS
1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744

/* 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;
}

1745 1746
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
1747
{
1748 1749 1750
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
1751
	else
1752 1753
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
1754 1755 1756 1757 1758 1759 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
}

/* 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
1824
static void dynamic_printk_setup(struct mod_debug *debug, unsigned int num)
1825
{
R
Rusty Russell 已提交
1826 1827
#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG
	unsigned int i;
1828

R
Rusty Russell 已提交
1829 1830 1831 1832 1833 1834
	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);
1835 1836
	}
#endif /* CONFIG_DYNAMIC_PRINTK_DEBUG */
R
Rusty Russell 已提交
1837
}
1838

1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852
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
1853 1854
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
1855
static noinline struct module *load_module(void __user *umod,
L
Linus Torvalds 已提交
1856 1857 1858 1859 1860 1861
				  unsigned long len,
				  const char __user *uargs)
{
	Elf_Ehdr *hdr;
	Elf_Shdr *sechdrs;
	char *secstrings, *args, *modmagic, *strtab = NULL;
1862
	char *staging;
A
Andrew Morton 已提交
1863 1864 1865
	unsigned int i;
	unsigned int symindex = 0;
	unsigned int strindex = 0;
R
Rusty Russell 已提交
1866 1867 1868
	unsigned int modindex, versindex, infoindex, pcpuindex;
	unsigned int num_kp, num_mcount;
	struct kernel_param *kp;
L
Linus Torvalds 已提交
1869 1870 1871
	struct module *mod;
	long err = 0;
	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
R
Rusty Russell 已提交
1872
	unsigned long *mseg;
1873
	mm_segment_t old_fs;
L
Linus Torvalds 已提交
1874 1875 1876 1877 1878 1879 1880 1881 1882 1883

	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);
1884 1885 1886 1887 1888 1889 1890

	/* 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
1891 1892 1893 1894 1895 1896 1897
	if (copy_from_user(hdr, umod, len) != 0) {
		err = -EFAULT;
		goto free_hdr;
	}

	/* Sanity checks against insmoding binaries or wrong arch,
           weird elf version */
1898
	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
L
Linus Torvalds 已提交
1899 1900 1901 1902 1903 1904 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
	    || 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
1943
	/* This is temporary: point mod into copy of data. */
L
Linus Torvalds 已提交
1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956
	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);

1957
	/* Don't keep modinfo and version sections. */
L
Linus Torvalds 已提交
1958
	sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1959
	sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
L
Linus Torvalds 已提交
1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974
#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) {
1975 1976 1977
		err = try_to_force_load(mod, "magic");
		if (err)
			goto free_hdr;
1978
	} else if (!same_magic(modmagic, vermagic, versindex)) {
L
Linus Torvalds 已提交
1979 1980 1981 1982 1983 1984
		printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
		       mod->name, modmagic, vermagic);
		err = -ENOEXEC;
		goto free_hdr;
	}

1985 1986 1987 1988 1989 1990 1991 1992
	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
1993
	/* Now copy in args */
1994 1995 1996
	args = strndup_user(uargs, ~0UL >> 1);
	if (IS_ERR(args)) {
		err = PTR_ERR(args);
L
Linus Torvalds 已提交
1997 1998
		goto free_hdr;
	}
1999

L
Linus Torvalds 已提交
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
	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,
2015 2016
					 sechdrs[pcpuindex].sh_addralign,
					 mod->name);
L
Linus Torvalds 已提交
2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
		if (!percpu) {
			err = -ENOMEM;
			goto free_mod;
		}
		sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
		mod->percpu = percpu;
	}

	/* Determine total sizes, and put offsets in sh_entsize.  For now
	   this is done generically; there doesn't appear to be any
	   special cases for the architectures. */
	layout_sections(mod, hdr, sechdrs, secstrings);

	/* Do the allocs. */
2031
	ptr = module_alloc_update_bounds(mod->core_size);
L
Linus Torvalds 已提交
2032 2033 2034 2035 2036 2037 2038
	if (!ptr) {
		err = -ENOMEM;
		goto free_percpu;
	}
	memset(ptr, 0, mod->core_size);
	mod->module_core = ptr;

2039
	ptr = module_alloc_update_bounds(mod->init_size);
L
Linus Torvalds 已提交
2040 2041 2042 2043 2044 2045 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
	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;

	/* Now we've moved module, initialize linked lists, etc. */
	module_unload_init(mod);

2074
	/* add kobject, so we can reference it. */
2075 2076
	err = mod_sysfs_init(mod);
	if (err)
2077
		goto free_unload;
K
Kay Sievers 已提交
2078

L
Linus Torvalds 已提交
2079 2080 2081
	/* Set up license info based on the info section */
	set_license(mod, get_modinfo(sechdrs, infoindex, "license"));

2082 2083 2084 2085 2086
	/*
	 * 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.
	 */
2087
	if (strcmp(mod->name, "ndiswrapper") == 0)
2088 2089 2090
		add_taint(TAINT_PROPRIETARY_MODULE);

	/* driverloader was caught wrongly pretending to be under GPL */
2091 2092
	if (strcmp(mod->name, "driverloader") == 0)
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2093

2094 2095 2096
	/* Set up MODINFO_ATTR fields */
	setup_modinfo(mod, sechdrs, infoindex);

L
Linus Torvalds 已提交
2097 2098 2099 2100 2101 2102
	/* 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
2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119
	/* 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
2120

2121
#ifdef CONFIG_UNUSED_SYMBOLS
R
Rusty Russell 已提交
2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144
	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);
2145
#endif
2146

L
Linus Torvalds 已提交
2147
#ifdef CONFIG_MODVERSIONS
R
Rusty Russell 已提交
2148 2149 2150
	if ((mod->num_syms && !mod->crcs)
	    || (mod->num_gpl_syms && !mod->gpl_crcs)
	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2151
#ifdef CONFIG_UNUSED_SYMBOLS
R
Rusty Russell 已提交
2152 2153
	    || (mod->num_unused_syms && !mod->unused_crcs)
	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2154 2155
#endif
		) {
2156 2157 2158 2159
		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
2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184
	}
#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;
	}

2185 2186 2187 2188 2189
        /* Find duplicate symbols */
	err = verify_export_symbols(mod);
	if (err < 0)
		goto cleanup;

L
Linus Torvalds 已提交
2190
  	/* Set up and sort exception table */
R
Rusty Russell 已提交
2191 2192 2193
	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
2194 2195 2196 2197 2198 2199 2200

	/* 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
2201
	if (!mod->taints) {
R
Rusty Russell 已提交
2202 2203 2204 2205 2206 2207
		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
2208
	}
2209

2210
	/* sechdrs[0].sh_size is always zero */
R
Rusty Russell 已提交
2211 2212
	mseg = section_objs(hdr, sechdrs, secstrings, "__mcount_loc",
			    sizeof(*mseg), &num_mcount);
2213
	ftrace_init_module(mod, mseg, mseg + num_mcount);
2214

L
Linus Torvalds 已提交
2215 2216 2217 2218
	err = module_finalize(hdr, sechdrs, mod);
	if (err < 0)
		goto cleanup;

2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236
	/* 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
2237
	mod->args = args;
R
Rusty Russell 已提交
2238
	if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
R
Rusty Russell 已提交
2239 2240 2241
		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
		       mod->name);

2242
	/* Now sew it into the lists so we can get lockdep and oops
2243 2244 2245 2246 2247 2248 2249
	 * 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);
2250

R
Rusty Russell 已提交
2251
	err = parse_args(mod->name, mod->args, kp, num_kp, NULL);
L
Linus Torvalds 已提交
2252
	if (err < 0)
2253
		goto unlink;
L
Linus Torvalds 已提交
2254

R
Rusty Russell 已提交
2255
	err = mod_sysfs_setup(mod, kp, num_kp);
L
Linus Torvalds 已提交
2256
	if (err < 0)
2257
		goto unlink;
L
Linus Torvalds 已提交
2258
	add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
R
Roland McGrath 已提交
2259
	add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
L
Linus Torvalds 已提交
2260 2261 2262 2263

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

2264
	stop_machine_destroy();
L
Linus Torvalds 已提交
2265 2266 2267
	/* Done! */
	return mod;

2268
 unlink:
2269
	stop_machine(__unlink_module, mod, NULL);
L
Linus Torvalds 已提交
2270 2271
	module_arch_cleanup(mod);
 cleanup:
2272 2273
	kobject_del(&mod->mkobj.kobj);
	kobject_put(&mod->mkobj.kobj);
2274
	ftrace_release(mod->module_core, mod->core_size);
2275
 free_unload:
L
Linus Torvalds 已提交
2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286
	module_unload_free(mod);
	module_free(mod, mod->module_init);
 free_core:
	module_free(mod, mod->module_core);
 free_percpu:
	if (percpu)
		percpu_modfree(percpu);
 free_mod:
	kfree(args);
 free_hdr:
	vfree(hdr);
2287
	stop_machine_destroy();
2288
	return ERR_PTR(err);
L
Linus Torvalds 已提交
2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309

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

/* This is where the real work happens */
asmlinkage long
sys_init_module(void __user *umod,
		unsigned long len,
		const char __user *uargs)
{
	struct module *mod;
	int ret = 0;

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

	/* Only one module load at a time, please */
2310
	if (mutex_lock_interruptible(&module_mutex) != 0)
L
Linus Torvalds 已提交
2311 2312 2313 2314 2315
		return -EINTR;

	/* Do all the hard work */
	mod = load_module(umod, len, uargs);
	if (IS_ERR(mod)) {
2316
		mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2317 2318 2319 2320
		return PTR_ERR(mod);
	}

	/* Drop lock so they can recurse */
2321
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2322

2323 2324
	blocking_notifier_call_chain(&module_notify_list,
			MODULE_STATE_COMING, mod);
L
Linus Torvalds 已提交
2325 2326 2327

	/* Start the module */
	if (mod->init != NULL)
2328
		ret = do_one_initcall(mod->init);
L
Linus Torvalds 已提交
2329 2330 2331 2332
	if (ret < 0) {
		/* Init routine failed: abort.  Try to protect us from
                   buggy refcounters. */
		mod->state = MODULE_STATE_GOING;
2333
		synchronize_sched();
R
Rusty Russell 已提交
2334
		module_put(mod);
2335 2336
		blocking_notifier_call_chain(&module_notify_list,
					     MODULE_STATE_GOING, mod);
R
Rusty Russell 已提交
2337 2338 2339
		mutex_lock(&module_mutex);
		free_module(mod);
		mutex_unlock(&module_mutex);
2340
		wake_up(&module_wq);
L
Linus Torvalds 已提交
2341 2342
		return ret;
	}
2343 2344 2345 2346 2347 2348 2349 2350
	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
2351

2352
	/* Now it's a first class citizen!  Wake up anyone waiting for it. */
L
Linus Torvalds 已提交
2353
	mod->state = MODULE_STATE_LIVE;
2354
	wake_up(&module_wq);
2355 2356
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_LIVE, mod);
2357 2358

	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
2359 2360 2361 2362 2363 2364
	/* 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;
2365
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381

	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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
D
Daniel Walker 已提交
2382
	return str[0] == '$' && strchr("atd", str[1])
L
Linus Torvalds 已提交
2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394
	       && (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 */
2395
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
2396
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
D
Daniel Walker 已提交
2397
	else
L
Linus Torvalds 已提交
2398 2399 2400
		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
2401
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422
	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
2423 2424 2425 2426
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
2427 2428 2429
	return mod->strtab + mod->symtab[best].st_name;
}

2430 2431
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
2432
const char *module_address_lookup(unsigned long addr,
2433 2434 2435 2436
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
2437 2438
{
	struct module *mod;
2439
	const char *ret = NULL;
L
Linus Torvalds 已提交
2440

2441
	preempt_disable();
2442
	list_for_each_entry_rcu(mod, &modules, list) {
2443 2444
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
2445 2446
			if (modname)
				*modname = mod->name;
2447 2448
			ret = get_ksymbol(mod, addr, size, offset);
			break;
L
Linus Torvalds 已提交
2449 2450
		}
	}
2451 2452 2453 2454 2455
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
2456
	preempt_enable();
2457
	return ret;
L
Linus Torvalds 已提交
2458 2459
}

2460 2461 2462 2463
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

2464
	preempt_disable();
2465
	list_for_each_entry_rcu(mod, &modules, list) {
2466 2467
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
2468 2469 2470 2471 2472
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
2473
			strlcpy(symname, sym, KSYM_NAME_LEN);
2474
			preempt_enable();
2475 2476 2477 2478
			return 0;
		}
	}
out:
2479
	preempt_enable();
2480 2481 2482
	return -ERANGE;
}

2483 2484 2485 2486 2487
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

2488
	preempt_disable();
2489
	list_for_each_entry_rcu(mod, &modules, list) {
2490 2491
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
2492 2493 2494 2495 2496 2497
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
2498
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
2499
			if (name)
2500
				strlcpy(name, sym, KSYM_NAME_LEN);
2501
			preempt_enable();
2502 2503 2504 2505
			return 0;
		}
	}
out:
2506
	preempt_enable();
2507 2508 2509
	return -ERANGE;
}

2510 2511
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
2512 2513 2514
{
	struct module *mod;

2515
	preempt_disable();
2516
	list_for_each_entry_rcu(mod, &modules, list) {
L
Linus Torvalds 已提交
2517 2518 2519
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
2520
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2521 2522
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
2523
			*exported = is_exported(name, *value, mod);
2524
			preempt_enable();
2525
			return 0;
L
Linus Torvalds 已提交
2526 2527 2528
		}
		symnum -= mod->num_symtab;
	}
2529
	preempt_enable();
2530
	return -ERANGE;
L
Linus Torvalds 已提交
2531 2532 2533 2534 2535 2536 2537
}

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

	for (i = 0; i < mod->num_symtab; i++)
2538 2539
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551
			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. */
2552
	preempt_disable();
L
Linus Torvalds 已提交
2553 2554 2555 2556 2557 2558
	if ((colon = strchr(name, ':')) != NULL) {
		*colon = '\0';
		if ((mod = find_module(name)) != NULL)
			ret = mod_find_symname(mod, colon+1);
		*colon = ':';
	} else {
2559
		list_for_each_entry_rcu(mod, &modules, list)
L
Linus Torvalds 已提交
2560 2561 2562
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
	}
2563
	preempt_enable();
L
Linus Torvalds 已提交
2564 2565 2566 2567
	return ret;
}
#endif /* CONFIG_KALLSYMS */

2568
static char *module_flags(struct module *mod, char *buf)
2569 2570 2571
{
	int bx = 0;

2572 2573 2574
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
2575
		buf[bx++] = '(';
A
Andi Kleen 已提交
2576
		if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
2577
			buf[bx++] = 'P';
A
Andi Kleen 已提交
2578
		if (mod->taints & (1 << TAINT_FORCED_MODULE))
2579
			buf[bx++] = 'F';
2580
		if (mod->taints & (1 << TAINT_CRAP))
2581
			buf[bx++] = 'C';
2582 2583 2584 2585 2586
		/*
		 * TAINT_FORCED_RMMOD: could be added.
		 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
		 * apply to modules.
		 */
2587 2588 2589 2590 2591 2592 2593

		/* 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++] = '+';
2594 2595 2596 2597 2598 2599 2600
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618
#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
2619 2620 2621
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
2622 2623
	char buf[8];

2624
	seq_printf(m, "%s %u",
L
Linus Torvalds 已提交
2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635
		   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);

2636 2637
	/* Taints info */
	if (mod->taints)
2638
		seq_printf(m, " %s", module_flags(mod, buf));
2639

L
Linus Torvalds 已提交
2640 2641 2642 2643 2644 2645 2646 2647 2648
	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 -.
*/
2649
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
2650 2651 2652 2653 2654 2655
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675
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
2676 2677 2678 2679 2680 2681
/* 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
2682
	preempt_disable();
2683
	list_for_each_entry_rcu(mod, &modules, list) {
L
Linus Torvalds 已提交
2684 2685
		if (mod->num_exentries == 0)
			continue;
D
Daniel Walker 已提交
2686

L
Linus Torvalds 已提交
2687 2688 2689 2690 2691 2692
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
R
Rusty Russell 已提交
2693
	preempt_enable();
L
Linus Torvalds 已提交
2694 2695

	/* Now, if we found one, we are running inside it now, hence
D
Daniel Walker 已提交
2696
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
2697 2698 2699
	return e;
}

2700 2701 2702 2703 2704 2705 2706
/*
 * Is this a valid module address?
 */
int is_module_address(unsigned long addr)
{
	struct module *mod;

R
Rusty Russell 已提交
2707
	preempt_disable();
2708

2709
	list_for_each_entry_rcu(mod, &modules, list) {
2710
		if (within_module_core(addr, mod)) {
R
Rusty Russell 已提交
2711
			preempt_enable();
2712 2713 2714 2715
			return 1;
		}
	}

R
Rusty Russell 已提交
2716
	preempt_enable();
2717 2718 2719 2720 2721

	return 0;
}


R
Rusty Russell 已提交
2722
/* Is this a valid kernel address? */
2723
__notrace_funcgraph struct module *__module_text_address(unsigned long addr)
L
Linus Torvalds 已提交
2724 2725 2726
{
	struct module *mod;

2727 2728 2729
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

2730
	list_for_each_entry_rcu(mod, &modules, list)
L
Linus Torvalds 已提交
2731 2732 2733 2734 2735 2736 2737 2738 2739 2740
		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
2741
	preempt_disable();
L
Linus Torvalds 已提交
2742
	mod = __module_text_address(addr);
R
Rusty Russell 已提交
2743
	preempt_enable();
L
Linus Torvalds 已提交
2744 2745 2746 2747 2748 2749 2750 2751

	return mod;
}

/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
2752
	char buf[8];
L
Linus Torvalds 已提交
2753 2754

	printk("Modules linked in:");
2755 2756 2757
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
	list_for_each_entry_rcu(mod, &modules, list)
2758
		printk(" %s%s", mod->name, module_flags(mod, buf));
2759
	preempt_enable();
2760 2761
	if (last_unloaded_module[0])
		printk(" [last unloaded: %s]", last_unloaded_module);
L
Linus Torvalds 已提交
2762 2763 2764 2765 2766 2767 2768 2769
	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
2770 2771

#ifdef CONFIG_MARKERS
2772
void module_update_markers(void)
M
Mathieu Desnoyers 已提交
2773 2774 2775 2776 2777 2778 2779
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry(mod, &modules, list)
		if (!mod->taints)
			marker_update_probe_range(mod->markers,
2780
				mod->markers + mod->num_markers);
M
Mathieu Desnoyers 已提交
2781 2782 2783
	mutex_unlock(&module_mutex);
}
#endif
M
Mathieu Desnoyers 已提交
2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 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

#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