module.c 67.4 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/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>
#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/unwind.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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#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
 * (add/delete uses stop_machine). */
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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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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);
	mod->taints |= flag;
}

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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;
}

/* 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_unused[];
extern const struct kernel_symbol __stop___ksymtab_unused[];
extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
extern const 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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extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
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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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/* 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;
}

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static bool always_ok(bool gplok, bool warn, const char *name)
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{
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	return true;
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}

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static bool printk_unused_warning(bool gplok, bool warn, const char *name)
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{
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	if (warn) {
		printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
		       "however this module is using it.\n", 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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	}
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	return true;
}

static bool gpl_only_unused_warning(bool gplok, bool warn, const char *name)
{
	if (!gplok)
		return false;
	return printk_unused_warning(gplok, warn, name);
}

static bool gpl_only(bool gplok, bool warn, const char *name)
{
	return gplok;
}

static bool warn_if_not_gpl(bool gplok, bool warn, const char *name)
{
	if (!gplok && warn) {
		printk(KERN_WARNING "Symbol %s is being used "
		       "by a non-GPL module, which will not "
		       "be allowed in the future\n", 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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	return true;
}
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struct symsearch {
	const struct kernel_symbol *start, *stop;
	const unsigned long *crcs;
	bool (*check)(bool gplok, bool warn, const char *name);
};

/* Look through this array of symbol tables for a symbol match which
 * passes the check function. */
static const struct kernel_symbol *search_symarrays(const struct symsearch *arr,
						    unsigned int num,
						    const char *name,
						    bool gplok,
						    bool warn,
						    const unsigned long **crc)
{
	unsigned int i;
	const struct kernel_symbol *ks;

	for (i = 0; i < num; i++) {
		ks = lookup_symbol(name, arr[i].start, arr[i].stop);
		if (!ks || !arr[i].check(gplok, warn, name))
			continue;

		if (crc)
			*crc = symversion(arr[i].crcs, ks - arr[i].start);
		return ks;
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	}
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	return NULL;
}

/* 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 module *mod;
	const struct kernel_symbol *ks;
	const struct symsearch arr[] = {
		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
		  always_ok },
		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
		  __start___kcrctab_gpl, gpl_only },
		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
		  __start___kcrctab_gpl_future, warn_if_not_gpl },
		{ __start___ksymtab_unused, __stop___ksymtab_unused,
		  __start___kcrctab_unused, printk_unused_warning },
		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
		  __start___kcrctab_unused_gpl, gpl_only_unused_warning },
	};
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	/* Core kernel first. */
	ks = search_symarrays(arr, ARRAY_SIZE(arr), name, gplok, warn, crc);
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	if (ks) {
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		if (owner)
			*owner = NULL;
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		return ks->value;
	}

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	/* Now try modules. */
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	list_for_each_entry(mod, &modules, list) {
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		struct symsearch arr[] = {
			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
			  always_ok },
			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
			  mod->gpl_crcs, gpl_only },
			{ mod->gpl_future_syms,
			  mod->gpl_future_syms + mod->num_gpl_future_syms,
			  mod->gpl_future_crcs, warn_if_not_gpl },
			{ mod->unused_syms,
			  mod->unused_syms + mod->num_unused_syms,
			  mod->unused_crcs, printk_unused_warning },
			{ mod->unused_gpl_syms,
			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,
			  mod->unused_gpl_crcs, gpl_only_unused_warning },
		};

		ks = search_symarrays(arr, ARRAY_SIZE(arr),
				      name, gplok, warn, crc);
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		if (ks) {
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			if (owner)
				*owner = mod;
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			return ks->value;
		}
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	}
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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;
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	int no_warn, err;
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	if (b == NULL || already_uses(a, b)) return 1;

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	/* 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
616
static inline int try_force_unload(unsigned int flags)
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{
	int ret = (flags & O_TRUNC);
	if (ret)
620
		add_taint(TAINT_FORCED_RMMOD);
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	return ret;
}
#else
624
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;

	/* If it's not unused, quit unless we are told to block. */
	if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
644
		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)
{
	struct stopref sref = { mod, flags, forced };

	return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
}

unsigned int module_refcount(struct module *mod)
{
	unsigned int i, total = 0;

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

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

static void wait_for_zero_refcount(struct module *mod)
{
675
	/* Since we might sleep for some time, release the mutex first */
676
	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;
685
	mutex_lock(&module_mutex);
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}

688 689
asmlinkage long
sys_delete_module(const char __user *name_user, unsigned int flags)
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{
	struct module *mod;
692
	char name[MODULE_NAME_LEN];
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	int ret, forced = 0;

695 696 697 698 699 700 701
	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';

702
	if (mutex_lock_interruptible(&module_mutex) != 0)
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		return -EINTR;

	mod = find_module(name);
	if (!mod) {
		ret = -ENOENT;
		goto out;
	}

	if (!list_empty(&mod->modules_which_use_me)) {
		/* Other modules depend on us: get rid of them first. */
		ret = -EWOULDBLOCK;
		goto out;
	}

	/* Doing init or already dying? */
	if (mod->state != MODULE_STATE_LIVE) {
		/* FIXME: if (force), slam module count and wake up
                   waiter --RR */
		DEBUGP("%s already dying\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) {
728
		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);

748
	mutex_unlock(&module_mutex);
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	/* Final destruction now noone is using it. */
750
	if (mod->exit != NULL)
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		mod->exit();
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	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
	mutex_lock(&module_mutex);
755
	/* Store the name of the last unloaded module for diagnostic purposes */
756
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
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	free_module(mod);

 out:
760
	mutex_unlock(&module_mutex);
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	return ret;
}

static void print_unload_info(struct seq_file *m, struct module *mod)
{
	struct module_use *use;
	int printed_something = 0;

	seq_printf(m, " %u ", module_refcount(mod));

	/* Always include a trailing , so userspace can differentiate
           between this and the old multi-field proc format. */
	list_for_each_entry(use, &mod->modules_which_use_me, list) {
		printed_something = 1;
		seq_printf(m, "%s,", use->module_which_uses->name);
	}

	if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
		seq_printf(m, "[permanent],");
	}

	if (!printed_something)
		seq_printf(m, "-");
}

void __symbol_put(const char *symbol)
{
	struct module *owner;

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	preempt_disable();
792
	if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false)))
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		BUG();
	module_put(owner);
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	preempt_enable();
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}
EXPORT_SYMBOL(__symbol_put);

void symbol_put_addr(void *addr)
{
801
	struct module *modaddr;
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803 804
	if (core_kernel_text((unsigned long)addr))
		return;
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806 807 808
	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)
{
815
	return sprintf(buffer, "%u\n", module_refcount(mod));
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}

static struct module_attribute refcnt = {
819
	.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 */
static void print_unload_info(struct seq_file *m, struct module *mod)
{
	/* We don't know the usage count, or what modules are using. */
	seq_printf(m, " - -");
}

static inline void module_unload_free(struct module *mod)
{
}

static inline int use_module(struct module *a, struct module *b)
{
849
	return strong_try_module_get(b) == 0;
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}

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

857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876
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 = {
877
	.attr = { .name = "initstate", .mode = 0444 },
878 879 880
	.show = show_initstate,
};

881 882 883
static struct module_attribute *modinfo_attrs[] = {
	&modinfo_version,
	&modinfo_srcversion,
884
	&initstate,
885 886 887 888 889 890
#ifdef CONFIG_MODULE_UNLOAD
	&refcnt,
#endif
	NULL,
};

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static const char vermagic[] = VERMAGIC_STRING;

#ifdef CONFIG_MODVERSIONS
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
			 struct module *mod, 
			 const unsigned long *crc)
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

	/* Exporting module didn't supply crcs?  OK, we're already tainted. */
	if (!crc)
		return 1;

	versions = (void *) sechdrs[versindex].sh_addr;
	num_versions = sechdrs[versindex].sh_size
		/ sizeof(struct modversion_info);

	for (i = 0; i < num_versions; i++) {
		if (strcmp(versions[i].name, symname) != 0)
			continue;

		if (versions[i].crc == *crc)
			return 1;
		printk("%s: disagrees about version of symbol %s\n",
		       mod->name, symname);
		DEBUGP("Found checksum %lX vs module %lX\n",
		       *crc, versions[i].crc);
		return 0;
	}
	/* Not in module's version table.  OK, but that taints the kernel. */
924
	if (!(tainted & TAINT_FORCED_MODULE))
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		printk("%s: no version for \"%s\" found: kernel tainted.\n",
		       mod->name, symname);
927
	add_taint_module(mod, TAINT_FORCED_MODULE);
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	return 1;
}

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

937
	if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
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		BUG();
939
	return check_version(sechdrs, versindex, "struct_module", mod, crc);
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}

/* First part is kernel version, which we ignore. */
static inline int same_magic(const char *amagic, const char *bmagic)
{
	amagic += strcspn(amagic, " ");
	bmagic += strcspn(bmagic, " ");
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
				struct module *mod, 
				const unsigned long *crc)
{
	return 1;
}

static inline int check_modstruct_version(Elf_Shdr *sechdrs,
					  unsigned int versindex,
					  struct module *mod)
{
	return 1;
}

static inline int same_magic(const char *amagic, const char *bmagic)
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

/* Resolve a symbol for this module.  I.e. if we find one, record usage.
   Must be holding module_mutex. */
static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
				    unsigned int versindex,
				    const char *name,
				    struct module *mod)
{
	struct module *owner;
	unsigned long ret;
	const unsigned long *crc;

983 984
	ret = find_symbol(name, &owner, &crc,
			  !(mod->taints & TAINT_PROPRIETARY_MODULE), true);
985
	if (!IS_ERR_VALUE(ret)) {
986 987
		/* use_module can fail due to OOM,
		   or module initialization or unloading */
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		if (!check_version(sechdrs, versindex, name, mod, crc) ||
		    !use_module(mod, owner))
990
			ret = -EINVAL;
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	}
	return ret;
}

/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
999
#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013
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);
}

1022 1023
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1024
	unsigned int section;
1025 1026 1027 1028 1029 1030

	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
1038

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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]);
1047 1048
	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];

1055
	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;
1062 1063 1064 1065 1066
		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:
1081
	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. */
1091
		free_sect_attrs(mod->sect_attrs);
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		mod->sect_attrs = NULL;
	}
}

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

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

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

static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
			     unsigned int i)
{
	if (notes_attrs->dir) {
		while (i-- > 0)
			sysfs_remove_bin_file(notes_attrs->dir,
					      &notes_attrs->attrs[i]);
		kobject_del(notes_attrs->dir);
	}
	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;
	}

1168
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
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	if (!notes_attrs->dir)
		goto out;

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

	mod->notes_attrs = notes_attrs;
	return;

  out:
	free_notes_attrs(notes_attrs, i);
}

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

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#else
1191

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static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
		char *sectstrings, Elf_Shdr *sechdrs)
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
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static inline void add_notes_attrs(struct module *mod, unsigned int nsect,
				   char *sectstrings, Elf_Shdr *sechdrs)
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
1209
#endif
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1211 1212
#ifdef CONFIG_SYSFS
int module_add_modinfo_attrs(struct module *mod)
1213 1214
{
	struct module_attribute *attr;
1215
	struct module_attribute *temp_attr;
1216 1217 1218
	int error = 0;
	int i;

1219 1220 1221 1222 1223 1224 1225
	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;
1226 1227
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1228 1229 1230 1231 1232
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
			++temp_attr;
		}
1233 1234 1235 1236
	}
	return error;
}

1237
void module_remove_modinfo_attrs(struct module *mod)
1238 1239 1240 1241
{
	struct module_attribute *attr;
	int i;

1242 1243 1244 1245
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1246
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1247 1248
		if (attr->free)
			attr->free(mod);
1249
	}
1250
	kfree(mod->modinfo_attrs);
1251
}
L
Linus Torvalds 已提交
1252

1253
int mod_sysfs_init(struct module *mod)
L
Linus Torvalds 已提交
1254 1255
{
	int err;
1256
	struct kobject *kobj;
L
Linus Torvalds 已提交
1257

1258 1259
	if (!module_sysfs_initialized) {
		printk(KERN_ERR "%s: module sysfs not initialized\n",
1260 1261 1262 1263
		       mod->name);
		err = -EINVAL;
		goto out;
	}
1264 1265 1266 1267 1268 1269 1270 1271 1272

	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;
	}

L
Linus Torvalds 已提交
1273
	mod->mkobj.mod = mod;
1274

1275 1276 1277 1278 1279 1280
	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
1281

1282
	/* delay uevent until full sysfs population */
K
Kay Sievers 已提交
1283 1284 1285 1286
out:
	return err;
}

1287
int mod_sysfs_setup(struct module *mod,
K
Kay Sievers 已提交
1288 1289 1290 1291 1292
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1293
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1294 1295
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1296
		goto out_unreg;
1297
	}
K
Kay Sievers 已提交
1298

L
Linus Torvalds 已提交
1299 1300
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1301
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1302

1303 1304
	err = module_add_modinfo_attrs(mod);
	if (err)
1305
		goto out_unreg_param;
1306

1307
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
Linus Torvalds 已提交
1308 1309
	return 0;

1310 1311
out_unreg_param:
	module_param_sysfs_remove(mod);
K
Kay Sievers 已提交
1312
out_unreg_holders:
1313
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1314
out_unreg:
1315
	kobject_put(&mod->mkobj.kobj);
L
Linus Torvalds 已提交
1316 1317
	return err;
}
1318
#endif
L
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1319 1320 1321

static void mod_kobject_remove(struct module *mod)
{
1322
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1323
	module_param_sysfs_remove(mod);
1324 1325 1326
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
	kobject_put(&mod->mkobj.kobj);
L
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1327 1328
}

1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339
/*
 * link the module with the whole machine is stopped with interrupts off
 * - this defends against kallsyms not taking locks
 */
static int __link_module(void *_mod)
{
	struct module *mod = _mod;
	list_add(&mod->list, &modules);
	return 0;
}

L
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1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350
/*
 * 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;
}

1351
/* Free a module, remove from lists, etc (must hold module_mutex). */
L
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1352 1353 1354 1355
static void free_module(struct module *mod)
{
	/* Delete from various lists */
	stop_machine_run(__unlink_module, mod, NR_CPUS);
R
Roland McGrath 已提交
1356
	remove_notes_attrs(mod);
L
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1357 1358 1359
	remove_sect_attrs(mod);
	mod_kobject_remove(mod);

1360 1361
	unwind_remove_table(mod->unwind_info, 0);

L
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1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

	/* This may be NULL, but that's OK */
	module_free(mod, mod->module_init);
	kfree(mod->args);
	if (mod->percpu)
		percpu_modfree(mod->percpu);

I
Ingo Molnar 已提交
1374 1375 1376
	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

L
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1377 1378 1379 1380 1381 1382 1383
	/* 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
1384
	unsigned long value;
L
Linus Torvalds 已提交
1385

R
Rusty Russell 已提交
1386
	preempt_disable();
1387
	value = find_symbol(symbol, &owner, NULL, true, true);
1388 1389 1390
	if (IS_ERR_VALUE(value))
		value = 0;
	else if (strong_try_module_get(owner))
L
Linus Torvalds 已提交
1391
		value = 0;
R
Rusty Russell 已提交
1392
	preempt_enable();
L
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1393 1394 1395 1396 1397

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

1398 1399
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1400
 * in the kernel or in some other module's exported symbol table.
1401 1402 1403
 */
static int verify_export_symbols(struct module *mod)
{
1404
	unsigned int i;
1405
	struct module *owner;
1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416
	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 },
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
	};
1417

1418 1419 1420 1421 1422 1423 1424 1425 1426 1427
	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;
			}
1428
		}
1429 1430
	}
	return 0;
1431 1432
}

1433
/* Change all symbols so that st_value encodes the pointer directly. */
L
Linus Torvalds 已提交
1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468
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.  */
1469
			if (!IS_ERR_VALUE(sym[i].st_value))
L
Linus Torvalds 已提交
1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569
				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;
}

/* Update size with this section: return offset. */
static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
{
	long ret;

	ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
	*size = ret + sechdr->sh_size;
	return ret;
}

/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
   might -- code, read-only data, read-write data, small data.  Tally
   sizes, and place the offsets into sh_entsize fields: high bit means it
   belongs in init. */
static void layout_sections(struct module *mod,
			    const Elf_Ehdr *hdr,
			    Elf_Shdr *sechdrs,
			    const char *secstrings)
{
	static unsigned long const masks[][2] = {
		/* NOTE: all executable code must be the first section
		 * in this array; otherwise modify the text_size
		 * finder in the two loops below */
		{ SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
		{ SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
		{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
		{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
	};
	unsigned int m, i;

	for (i = 0; i < hdr->e_shnum; i++)
		sechdrs[i].sh_entsize = ~0UL;

	DEBUGP("Core section allocation order:\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;
			s->sh_entsize = get_offset(&mod->core_size, s);
			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;
			s->sh_entsize = (get_offset(&mod->init_size, s)
					 | 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";

1570 1571
	if (!license_is_gpl_compatible(license)) {
		if (!(tainted & TAINT_PROPRIETARY_MODULE))
1572
			printk(KERN_WARNING "%s: module license '%s' taints "
1573 1574
				"kernel.\n", mod->name, license);
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
L
Linus Torvalds 已提交
1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611
	}
}

/* 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;
}

1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626
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
1627
#ifdef CONFIG_KALLSYMS
1628
static int is_exported(const char *name, const struct module *mod)
L
Linus Torvalds 已提交
1629
{
1630 1631 1632
	if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
		return 1;
	else
1633
		if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
L
Linus Torvalds 已提交
1634
			return 1;
1635 1636
		else
			return 0;
L
Linus Torvalds 已提交
1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 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
}

/* As per nm */
static char elf_type(const Elf_Sym *sym,
		     Elf_Shdr *sechdrs,
		     const char *secstrings,
		     struct module *mod)
{
	if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
			return 'v';
		else
			return 'w';
	}
	if (sym->st_shndx == SHN_UNDEF)
		return 'U';
	if (sym->st_shndx == SHN_ABS)
		return 'a';
	if (sym->st_shndx >= SHN_LORESERVE)
		return '?';
	if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
		return 't';
	if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
	    && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
		if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
			return 'r';
		else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
			return 'g';
		else
			return 'd';
	}
	if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
		if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
			return 's';
		else
			return 'b';
	}
	if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
		    ".debug", strlen(".debug")) == 0)
		return 'n';
	return '?';
}

static void add_kallsyms(struct module *mod,
			 Elf_Shdr *sechdrs,
			 unsigned int symindex,
			 unsigned int strindex,
			 const char *secstrings)
{
	unsigned int i;

	mod->symtab = (void *)sechdrs[symindex].sh_addr;
	mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
	mod->strtab = (void *)sechdrs[strindex].sh_addr;

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
		mod->symtab[i].st_info
			= elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
}
#else
static inline void add_kallsyms(struct module *mod,
				Elf_Shdr *sechdrs,
				unsigned int symindex,
				unsigned int strindex,
				const char *secstrings)
{
}
#endif /* CONFIG_KALLSYMS */

/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
static struct module *load_module(void __user *umod,
				  unsigned long len,
				  const char __user *uargs)
{
	Elf_Ehdr *hdr;
	Elf_Shdr *sechdrs;
	char *secstrings, *args, *modmagic, *strtab = NULL;
A
Andrew Morton 已提交
1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736
	unsigned int i;
	unsigned int symindex = 0;
	unsigned int strindex = 0;
	unsigned int setupindex;
	unsigned int exindex;
	unsigned int exportindex;
	unsigned int modindex;
	unsigned int obsparmindex;
	unsigned int infoindex;
	unsigned int gplindex;
	unsigned int crcindex;
	unsigned int gplcrcindex;
	unsigned int versindex;
	unsigned int pcpuindex;
	unsigned int gplfutureindex;
	unsigned int gplfuturecrcindex;
	unsigned int unwindex = 0;
	unsigned int unusedindex;
	unsigned int unusedcrcindex;
	unsigned int unusedgplindex;
	unsigned int unusedgplcrcindex;
M
Mathieu Desnoyers 已提交
1737 1738
	unsigned int markersindex;
	unsigned int markersstringsindex;
L
Linus Torvalds 已提交
1739 1740 1741 1742
	struct module *mod;
	long err = 0;
	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
	struct exception_table_entry *extable;
1743
	mm_segment_t old_fs;
L
Linus Torvalds 已提交
1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 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

	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);
	if (copy_from_user(hdr, umod, len) != 0) {
		err = -EFAULT;
		goto free_hdr;
	}

	/* Sanity checks against insmoding binaries or wrong arch,
           weird elf version */
	if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
	    || hdr->e_type != ET_REL
	    || !elf_check_arch(hdr)
	    || hdr->e_shentsize != sizeof(*sechdrs)) {
		err = -ENOEXEC;
		goto free_hdr;
	}

	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
		goto truncated;

	/* Convenience variables */
	sechdrs = (void *)hdr + hdr->e_shoff;
	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
	sechdrs[0].sh_addr = 0;

	for (i = 1; i < hdr->e_shnum; i++) {
		if (sechdrs[i].sh_type != SHT_NOBITS
		    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
			goto truncated;

		/* Mark all sections sh_addr with their address in the
		   temporary image. */
		sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;

		/* Internal symbols and strings. */
		if (sechdrs[i].sh_type == SHT_SYMTAB) {
			symindex = i;
			strindex = sechdrs[i].sh_link;
			strtab = (char *)hdr + sechdrs[strindex].sh_offset;
		}
#ifndef CONFIG_MODULE_UNLOAD
		/* Don't load .exit sections */
		if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
			sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
#endif
	}

	modindex = find_sec(hdr, sechdrs, secstrings,
			    ".gnu.linkonce.this_module");
	if (!modindex) {
		printk(KERN_WARNING "No module found in object\n");
		err = -ENOEXEC;
		goto free_hdr;
	}
	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;
	}

	/* Optional sections */
	exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
	gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1818
	gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1819 1820
	unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
	unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
L
Linus Torvalds 已提交
1821 1822
	crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
	gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1823
	gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1824 1825
	unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
	unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
L
Linus Torvalds 已提交
1826 1827 1828 1829 1830 1831
	setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
	exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
	obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
	versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
	infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
	pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1832 1833 1834
#ifdef ARCH_UNWIND_SECTION_NAME
	unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
#endif
L
Linus Torvalds 已提交
1835

1836
	/* Don't keep modinfo and version sections. */
L
Linus Torvalds 已提交
1837
	sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1838
	sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
L
Linus Torvalds 已提交
1839 1840 1841 1842 1843
#ifdef CONFIG_KALLSYMS
	/* Keep symbol and string tables for decoding later. */
	sechdrs[symindex].sh_flags |= SHF_ALLOC;
	sechdrs[strindex].sh_flags |= SHF_ALLOC;
#endif
1844 1845
	if (unwindex)
		sechdrs[unwindex].sh_flags |= SHF_ALLOC;
L
Linus Torvalds 已提交
1846 1847 1848 1849 1850 1851 1852 1853 1854 1855

	/* 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) {
1856
		add_taint_module(mod, TAINT_FORCED_MODULE);
L
Linus Torvalds 已提交
1857 1858 1859 1860 1861 1862 1863 1864 1865 1866
		printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
		       mod->name);
	} else if (!same_magic(modmagic, vermagic)) {
		printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
		       mod->name, modmagic, vermagic);
		err = -ENOEXEC;
		goto free_hdr;
	}

	/* Now copy in args */
1867 1868 1869
	args = strndup_user(uargs, ~0UL >> 1);
	if (IS_ERR(args)) {
		err = PTR_ERR(args);
L
Linus Torvalds 已提交
1870 1871
		goto free_hdr;
	}
1872

L
Linus Torvalds 已提交
1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887
	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,
1888 1889
					 sechdrs[pcpuindex].sh_addralign,
					 mod->name);
L
Linus Torvalds 已提交
1890 1891 1892 1893 1894 1895 1896 1897 1898 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 1943 1944 1945 1946
		if (!percpu) {
			err = -ENOMEM;
			goto free_mod;
		}
		sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
		mod->percpu = percpu;
	}

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

	/* Do the allocs. */
	ptr = module_alloc(mod->core_size);
	if (!ptr) {
		err = -ENOMEM;
		goto free_percpu;
	}
	memset(ptr, 0, mod->core_size);
	mod->module_core = ptr;

	ptr = module_alloc(mod->init_size);
	if (!ptr && mod->init_size) {
		err = -ENOMEM;
		goto free_core;
	}
	memset(ptr, 0, mod->init_size);
	mod->module_init = ptr;

	/* Transfer each section which specifies SHF_ALLOC */
	DEBUGP("final section addresses:\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);

1947
	/* add kobject, so we can reference it. */
1948 1949
	err = mod_sysfs_init(mod);
	if (err)
1950
		goto free_unload;
K
Kay Sievers 已提交
1951

L
Linus Torvalds 已提交
1952 1953 1954
	/* Set up license info based on the info section */
	set_license(mod, get_modinfo(sechdrs, infoindex, "license"));

1955 1956 1957 1958 1959
	/*
	 * 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.
	 */
1960
	if (strcmp(mod->name, "ndiswrapper") == 0)
1961 1962 1963
		add_taint(TAINT_PROPRIETARY_MODULE);

	/* driverloader was caught wrongly pretending to be under GPL */
1964 1965
	if (strcmp(mod->name, "driverloader") == 0)
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1966

1967 1968 1969
	/* Set up MODINFO_ATTR fields */
	setup_modinfo(mod, sechdrs, infoindex);

L
Linus Torvalds 已提交
1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984
	/* Fix up syms, so that st_value is a pointer to location. */
	err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
			       mod);
	if (err < 0)
		goto cleanup;

	/* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
	mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
	mod->syms = (void *)sechdrs[exportindex].sh_addr;
	if (crcindex)
		mod->crcs = (void *)sechdrs[crcindex].sh_addr;
	mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
	mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
	if (gplcrcindex)
		mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1985 1986
	mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
					sizeof(*mod->gpl_future_syms);
1987 1988 1989 1990
	mod->num_unused_syms = sechdrs[unusedindex].sh_size /
					sizeof(*mod->unused_syms);
	mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
					sizeof(*mod->unused_gpl_syms);
1991 1992 1993
	mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
	if (gplfuturecrcindex)
		mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
L
Linus Torvalds 已提交
1994

1995 1996 1997 1998 1999
	mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
	if (unusedcrcindex)
		mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
	mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
	if (unusedgplcrcindex)
2000 2001
		mod->unused_gpl_crcs
			= (void *)sechdrs[unusedgplcrcindex].sh_addr;
2002

L
Linus Torvalds 已提交
2003
#ifdef CONFIG_MODVERSIONS
D
Daniel Walker 已提交
2004
	if ((mod->num_syms && !crcindex) ||
2005
	    (mod->num_gpl_syms && !gplcrcindex) ||
2006 2007 2008
	    (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
	    (mod->num_unused_syms && !unusedcrcindex) ||
	    (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
L
Linus Torvalds 已提交
2009 2010
		printk(KERN_WARNING "%s: No versions for exported symbols."
		       " Tainting kernel.\n", mod->name);
2011
		add_taint_module(mod, TAINT_FORCED_MODULE);
L
Linus Torvalds 已提交
2012 2013
	}
#endif
M
Mathieu Desnoyers 已提交
2014 2015 2016
	markersindex = find_sec(hdr, sechdrs, secstrings, "__markers");
 	markersstringsindex = find_sec(hdr, sechdrs, secstrings,
					"__markers_strings");
L
Linus Torvalds 已提交
2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038

	/* 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;
	}
M
Mathieu Desnoyers 已提交
2039 2040 2041 2042 2043
#ifdef CONFIG_MARKERS
	mod->markers = (void *)sechdrs[markersindex].sh_addr;
	mod->num_markers =
		sechdrs[markersindex].sh_size / sizeof(*mod->markers);
#endif
L
Linus Torvalds 已提交
2044

2045 2046 2047 2048 2049 2050
        /* Find duplicate symbols */
	err = verify_export_symbols(mod);

	if (err < 0)
		goto cleanup;

L
Linus Torvalds 已提交
2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061
  	/* Set up and sort exception table */
	mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
	mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
	sort_extable(extable, extable + mod->num_exentries);

	/* Finally, copy percpu area over. */
	percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
		       sechdrs[pcpuindex].sh_size);

	add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);

M
Mathieu Desnoyers 已提交
2062 2063 2064
#ifdef CONFIG_MARKERS
	if (!mod->taints)
		marker_update_probe_range(mod->markers,
2065
			mod->markers + mod->num_markers);
M
Mathieu Desnoyers 已提交
2066
#endif
L
Linus Torvalds 已提交
2067 2068 2069 2070
	err = module_finalize(hdr, sechdrs, mod);
	if (err < 0)
		goto cleanup;

2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088
	/* 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
2089
	mod->args = args;
R
Rusty Russell 已提交
2090 2091 2092 2093
	if (obsparmindex)
		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
		       mod->name);

2094 2095 2096 2097 2098
	/* Now sew it into the lists so we can get lockdep and oops
         * info during argument parsing.  Noone should access us, since
         * strong_try_module_get() will fail. */
	stop_machine_run(__link_module, mod, NR_CPUS);

R
Rusty Russell 已提交
2099 2100 2101 2102 2103 2104 2105
	/* Size of section 0 is 0, so this works well if no params */
	err = parse_args(mod->name, mod->args,
			 (struct kernel_param *)
			 sechdrs[setupindex].sh_addr,
			 sechdrs[setupindex].sh_size
			 / sizeof(struct kernel_param),
			 NULL);
L
Linus Torvalds 已提交
2106
	if (err < 0)
2107
		goto unlink;
L
Linus Torvalds 已提交
2108

D
Daniel Walker 已提交
2109
	err = mod_sysfs_setup(mod,
L
Linus Torvalds 已提交
2110 2111 2112 2113 2114
			      (struct kernel_param *)
			      sechdrs[setupindex].sh_addr,
			      sechdrs[setupindex].sh_size
			      / sizeof(struct kernel_param));
	if (err < 0)
2115
		goto unlink;
L
Linus Torvalds 已提交
2116
	add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
R
Roland McGrath 已提交
2117
	add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
L
Linus Torvalds 已提交
2118

2119 2120
	/* Size of section 0 is 0, so this works well if no unwind info. */
	mod->unwind_info = unwind_add_table(mod,
D
Daniel Walker 已提交
2121 2122
					    (void *)sechdrs[unwindex].sh_addr,
					    sechdrs[unwindex].sh_size);
2123

L
Linus Torvalds 已提交
2124 2125 2126 2127 2128 2129
	/* Get rid of temporary copy */
	vfree(hdr);

	/* Done! */
	return mod;

2130 2131
 unlink:
	stop_machine_run(__unlink_module, mod, NR_CPUS);
L
Linus Torvalds 已提交
2132 2133
	module_arch_cleanup(mod);
 cleanup:
2134 2135 2136
	kobject_del(&mod->mkobj.kobj);
	kobject_put(&mod->mkobj.kobj);
 free_unload:
L
Linus Torvalds 已提交
2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147
	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);
2148
	return ERR_PTR(err);
L
Linus Torvalds 已提交
2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169

 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 */
2170
	if (mutex_lock_interruptible(&module_mutex) != 0)
L
Linus Torvalds 已提交
2171 2172 2173 2174 2175
		return -EINTR;

	/* Do all the hard work */
	mod = load_module(umod, len, uargs);
	if (IS_ERR(mod)) {
2176
		mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2177 2178 2179 2180
		return PTR_ERR(mod);
	}

	/* Drop lock so they can recurse */
2181
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2182

2183 2184
	blocking_notifier_call_chain(&module_notify_list,
			MODULE_STATE_COMING, mod);
L
Linus Torvalds 已提交
2185 2186 2187 2188 2189 2190 2191 2192

	/* Start the module */
	if (mod->init != NULL)
		ret = mod->init();
	if (ret < 0) {
		/* Init routine failed: abort.  Try to protect us from
                   buggy refcounters. */
		mod->state = MODULE_STATE_GOING;
2193
		synchronize_sched();
R
Rusty Russell 已提交
2194
		module_put(mod);
2195 2196
		blocking_notifier_call_chain(&module_notify_list,
					     MODULE_STATE_GOING, mod);
R
Rusty Russell 已提交
2197 2198 2199
		mutex_lock(&module_mutex);
		free_module(mod);
		mutex_unlock(&module_mutex);
2200
		wake_up(&module_wq);
L
Linus Torvalds 已提交
2201 2202
		return ret;
	}
2203 2204 2205 2206 2207 2208 2209 2210
	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
2211

2212
	/* Now it's a first class citizen!  Wake up anyone waiting for it. */
L
Linus Torvalds 已提交
2213
	mod->state = MODULE_STATE_LIVE;
2214 2215 2216
	wake_up(&module_wq);

	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
2217 2218
	/* Drop initial reference. */
	module_put(mod);
2219
	unwind_remove_table(mod->unwind_info, 1);
L
Linus Torvalds 已提交
2220 2221 2222 2223
	module_free(mod, mod->module_init);
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_text_size = 0;
2224
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240

	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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
D
Daniel Walker 已提交
2241
	return str[0] == '$' && strchr("atd", str[1])
L
Linus Torvalds 已提交
2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255
	       && (str[2] == '\0' || str[2] == '.');
}

static const char *get_ksymbol(struct module *mod,
			       unsigned long addr,
			       unsigned long *size,
			       unsigned long *offset)
{
	unsigned int i, best = 0;
	unsigned long nextval;

	/* At worse, next value is at end of module */
	if (within(addr, mod->module_init, mod->init_size))
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
D
Daniel Walker 已提交
2256
	else
L
Linus Torvalds 已提交
2257 2258 2259
		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
2260
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281
	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
2282 2283 2284 2285
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
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	return mod->strtab + mod->symtab[best].st_name;
}

2289 2290
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
2291
const char *module_address_lookup(unsigned long addr,
2292 2293 2294 2295
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
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2296 2297
{
	struct module *mod;
2298
	const char *ret = NULL;
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2299

2300
	preempt_disable();
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	list_for_each_entry(mod, &modules, list) {
		if (within(addr, mod->module_init, mod->init_size)
		    || within(addr, mod->module_core, mod->core_size)) {
2304 2305
			if (modname)
				*modname = mod->name;
2306 2307
			ret = get_ksymbol(mod, addr, size, offset);
			break;
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2308 2309
		}
	}
2310 2311 2312 2313 2314
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
2315
	preempt_enable();
2316
	return ret;
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}

2319 2320 2321 2322
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

2323
	preempt_disable();
2324 2325 2326 2327 2328 2329 2330 2331
	list_for_each_entry(mod, &modules, list) {
		if (within(addr, mod->module_init, mod->init_size) ||
		    within(addr, mod->module_core, mod->core_size)) {
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
2332
			strlcpy(symname, sym, KSYM_NAME_LEN);
2333
			preempt_enable();
2334 2335 2336 2337
			return 0;
		}
	}
out:
2338
	preempt_enable();
2339 2340 2341
	return -ERANGE;
}

2342 2343 2344 2345 2346
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

2347
	preempt_disable();
2348 2349 2350 2351 2352 2353 2354 2355 2356
	list_for_each_entry(mod, &modules, list) {
		if (within(addr, mod->module_init, mod->init_size) ||
		    within(addr, mod->module_core, mod->core_size)) {
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
2357
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
2358
			if (name)
2359
				strlcpy(name, sym, KSYM_NAME_LEN);
2360
			preempt_enable();
2361 2362 2363 2364
			return 0;
		}
	}
out:
2365
	preempt_enable();
2366 2367 2368
	return -ERANGE;
}

2369 2370
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
			char *name, char *module_name, int *exported)
L
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2371 2372 2373
{
	struct module *mod;

2374
	preempt_disable();
L
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2375 2376 2377 2378
	list_for_each_entry(mod, &modules, list) {
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
2379
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2380 2381
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
2382
			*exported = is_exported(name, mod);
2383
			preempt_enable();
2384
			return 0;
L
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2385 2386 2387
		}
		symnum -= mod->num_symtab;
	}
2388
	preempt_enable();
2389
	return -ERANGE;
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2390 2391 2392 2393 2394 2395 2396
}

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

	for (i = 0; i < mod->num_symtab; i++)
2397 2398
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
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2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410
			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. */
2411
	preempt_disable();
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2412 2413 2414 2415 2416 2417 2418 2419 2420 2421
	if ((colon = strchr(name, ':')) != NULL) {
		*colon = '\0';
		if ((mod = find_module(name)) != NULL)
			ret = mod_find_symname(mod, colon+1);
		*colon = ':';
	} else {
		list_for_each_entry(mod, &modules, list)
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
	}
2422
	preempt_enable();
L
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2423 2424 2425 2426 2427 2428 2429
	return ret;
}
#endif /* CONFIG_KALLSYMS */

/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
2430
	mutex_lock(&module_mutex);
2431
	return seq_list_start(&modules, *pos);
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2432 2433 2434 2435
}

static void *m_next(struct seq_file *m, void *p, loff_t *pos)
{
2436
	return seq_list_next(p, &modules, pos);
L
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2437 2438 2439 2440
}

static void m_stop(struct seq_file *m, void *p)
{
2441
	mutex_unlock(&module_mutex);
L
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2442 2443
}

2444
static char *module_flags(struct module *mod, char *buf)
2445 2446 2447
{
	int bx = 0;

2448 2449 2450
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
2451
		buf[bx++] = '(';
2452
		if (mod->taints & TAINT_PROPRIETARY_MODULE)
2453
			buf[bx++] = 'P';
2454
		if (mod->taints & TAINT_FORCED_MODULE)
2455 2456 2457 2458 2459 2460
			buf[bx++] = 'F';
		/*
		 * TAINT_FORCED_RMMOD: could be added.
		 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
		 * apply to modules.
		 */
2461 2462 2463 2464 2465 2466 2467

		/* 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++] = '+';
2468 2469 2470 2471 2472 2473 2474
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

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2475 2476 2477
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
2478 2479
	char buf[8];

L
Linus Torvalds 已提交
2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491
	seq_printf(m, "%s %lu",
		   mod->name, mod->init_size + mod->core_size);
	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
		   mod->state == MODULE_STATE_GOING ? "Unloading":
		   mod->state == MODULE_STATE_COMING ? "Loading":
		   "Live");
	/* Used by oprofile and other similar tools. */
	seq_printf(m, " 0x%p", mod->module_core);

2492 2493
	/* Taints info */
	if (mod->taints)
2494
		seq_printf(m, " %s", module_flags(mod, buf));
2495

L
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2496 2497 2498 2499 2500 2501 2502 2503 2504
	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 -.
*/
2505
const struct seq_operations modules_op = {
L
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2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
	const struct exception_table_entry *e = NULL;
	struct module *mod;

R
Rusty Russell 已提交
2518
	preempt_disable();
L
Linus Torvalds 已提交
2519 2520 2521
	list_for_each_entry(mod, &modules, list) {
		if (mod->num_exentries == 0)
			continue;
D
Daniel Walker 已提交
2522

L
Linus Torvalds 已提交
2523 2524 2525 2526 2527 2528
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
R
Rusty Russell 已提交
2529
	preempt_enable();
L
Linus Torvalds 已提交
2530 2531

	/* Now, if we found one, we are running inside it now, hence
D
Daniel Walker 已提交
2532
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
2533 2534 2535
	return e;
}

2536 2537 2538 2539 2540 2541 2542
/*
 * Is this a valid module address?
 */
int is_module_address(unsigned long addr)
{
	struct module *mod;

R
Rusty Russell 已提交
2543
	preempt_disable();
2544 2545 2546

	list_for_each_entry(mod, &modules, list) {
		if (within(addr, mod->module_core, mod->core_size)) {
R
Rusty Russell 已提交
2547
			preempt_enable();
2548 2549 2550 2551
			return 1;
		}
	}

R
Rusty Russell 已提交
2552
	preempt_enable();
2553 2554 2555 2556 2557

	return 0;
}


R
Rusty Russell 已提交
2558
/* Is this a valid kernel address? */
L
Linus Torvalds 已提交
2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573
struct module *__module_text_address(unsigned long addr)
{
	struct module *mod;

	list_for_each_entry(mod, &modules, list)
		if (within(addr, mod->module_init, mod->init_text_size)
		    || within(addr, mod->module_core, mod->core_text_size))
			return mod;
	return NULL;
}

struct module *module_text_address(unsigned long addr)
{
	struct module *mod;

R
Rusty Russell 已提交
2574
	preempt_disable();
L
Linus Torvalds 已提交
2575
	mod = __module_text_address(addr);
R
Rusty Russell 已提交
2576
	preempt_enable();
L
Linus Torvalds 已提交
2577 2578 2579 2580 2581 2582 2583 2584

	return mod;
}

/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
2585
	char buf[8];
L
Linus Torvalds 已提交
2586 2587 2588

	printk("Modules linked in:");
	list_for_each_entry(mod, &modules, list)
2589
		printk(" %s%s", mod->name, module_flags(mod, buf));
2590 2591
	if (last_unloaded_module[0])
		printk(" [last unloaded: %s]", last_unloaded_module);
L
Linus Torvalds 已提交
2592 2593 2594 2595 2596 2597 2598 2599
	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
2600 2601

#ifdef CONFIG_MARKERS
2602
void module_update_markers(void)
M
Mathieu Desnoyers 已提交
2603 2604 2605 2606 2607 2608 2609
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry(mod, &modules, list)
		if (!mod->taints)
			marker_update_probe_range(mod->markers,
2610
				mod->markers + mod->num_markers);
M
Mathieu Desnoyers 已提交
2611 2612 2613
	mutex_unlock(&module_mutex);
}
#endif