Root/kernel/module.c

1/*
2   Copyright (C) 2002 Richard Henderson
3   Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
4
5    This program is free software; you can redistribute it and/or modify
6    it under the terms of the GNU General Public License as published by
7    the Free Software Foundation; either version 2 of the License, or
8    (at your option) any later version.
9
10    This program is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13    GNU General Public License for more details.
14
15    You should have received a copy of the GNU General Public License
16    along with this program; if not, write to the Free Software
17    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18*/
19#include <linux/module.h>
20#include <linux/moduleloader.h>
21#include <linux/ftrace_event.h>
22#include <linux/init.h>
23#include <linux/kallsyms.h>
24#include <linux/fs.h>
25#include <linux/sysfs.h>
26#include <linux/kernel.h>
27#include <linux/slab.h>
28#include <linux/vmalloc.h>
29#include <linux/elf.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/syscalls.h>
33#include <linux/fcntl.h>
34#include <linux/rcupdate.h>
35#include <linux/capability.h>
36#include <linux/cpu.h>
37#include <linux/moduleparam.h>
38#include <linux/errno.h>
39#include <linux/err.h>
40#include <linux/vermagic.h>
41#include <linux/notifier.h>
42#include <linux/sched.h>
43#include <linux/stop_machine.h>
44#include <linux/device.h>
45#include <linux/string.h>
46#include <linux/mutex.h>
47#include <linux/rculist.h>
48#include <asm/uaccess.h>
49#include <asm/cacheflush.h>
50#include <asm/mmu_context.h>
51#include <linux/license.h>
52#include <asm/sections.h>
53#include <linux/tracepoint.h>
54#include <linux/ftrace.h>
55#include <linux/async.h>
56#include <linux/percpu.h>
57#include <linux/kmemleak.h>
58
59#define CREATE_TRACE_POINTS
60#include <trace/events/module.h>
61
62#if 0
63#define DEBUGP printk
64#else
65#define DEBUGP(fmt , a...)
66#endif
67
68#ifndef ARCH_SHF_SMALL
69#define ARCH_SHF_SMALL 0
70#endif
71
72/* If this is set, the section belongs in the init part of the module */
73#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
74
75/*
76 * Mutex protects:
77 * 1) List of modules (also safely readable with preempt_disable),
78 * 2) module_use links,
79 * 3) module_addr_min/module_addr_max.
80 * (delete uses stop_machine/add uses RCU list operations). */
81DEFINE_MUTEX(module_mutex);
82EXPORT_SYMBOL_GPL(module_mutex);
83static LIST_HEAD(modules);
84#ifdef CONFIG_KGDB_KDB
85struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
86#endif /* CONFIG_KGDB_KDB */
87
88
89/* Block module loading/unloading? */
90int modules_disabled = 0;
91
92/* Waiting for a module to finish initializing? */
93static DECLARE_WAIT_QUEUE_HEAD(module_wq);
94
95static BLOCKING_NOTIFIER_HEAD(module_notify_list);
96
97/* Bounds of module allocation, for speeding __module_address.
98 * Protected by module_mutex. */
99static unsigned long module_addr_min = -1UL, module_addr_max = 0;
100
101int register_module_notifier(struct notifier_block * nb)
102{
103    return blocking_notifier_chain_register(&module_notify_list, nb);
104}
105EXPORT_SYMBOL(register_module_notifier);
106
107int unregister_module_notifier(struct notifier_block * nb)
108{
109    return blocking_notifier_chain_unregister(&module_notify_list, nb);
110}
111EXPORT_SYMBOL(unregister_module_notifier);
112
113struct load_info {
114    Elf_Ehdr *hdr;
115    unsigned long len;
116    Elf_Shdr *sechdrs;
117    char *secstrings, *strtab;
118    unsigned long *strmap;
119    unsigned long symoffs, stroffs;
120    struct _ddebug *debug;
121    unsigned int num_debug;
122    struct {
123        unsigned int sym, str, mod, vers, info, pcpu;
124    } index;
125};
126
127/* We require a truly strong try_module_get(): 0 means failure due to
128   ongoing or failed initialization etc. */
129static inline int strong_try_module_get(struct module *mod)
130{
131    if (mod && mod->state == MODULE_STATE_COMING)
132        return -EBUSY;
133    if (try_module_get(mod))
134        return 0;
135    else
136        return -ENOENT;
137}
138
139static inline void add_taint_module(struct module *mod, unsigned flag)
140{
141    add_taint(flag);
142    mod->taints |= (1U << flag);
143}
144
145/*
146 * A thread that wants to hold a reference to a module only while it
147 * is running can call this to safely exit. nfsd and lockd use this.
148 */
149void __module_put_and_exit(struct module *mod, long code)
150{
151    module_put(mod);
152    do_exit(code);
153}
154EXPORT_SYMBOL(__module_put_and_exit);
155
156/* Find a module section: 0 means not found. */
157static unsigned int find_sec(const struct load_info *info, const char *name)
158{
159    unsigned int i;
160
161    for (i = 1; i < info->hdr->e_shnum; i++) {
162        Elf_Shdr *shdr = &info->sechdrs[i];
163        /* Alloc bit cleared means "ignore it." */
164        if ((shdr->sh_flags & SHF_ALLOC)
165            && strcmp(info->secstrings + shdr->sh_name, name) == 0)
166            return i;
167    }
168    return 0;
169}
170
171/* Find a module section, or NULL. */
172static void *section_addr(const struct load_info *info, const char *name)
173{
174    /* Section 0 has sh_addr 0. */
175    return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
176}
177
178/* Find a module section, or NULL. Fill in number of "objects" in section. */
179static void *section_objs(const struct load_info *info,
180              const char *name,
181              size_t object_size,
182              unsigned int *num)
183{
184    unsigned int sec = find_sec(info, name);
185
186    /* Section 0 has sh_addr 0 and sh_size 0. */
187    *num = info->sechdrs[sec].sh_size / object_size;
188    return (void *)info->sechdrs[sec].sh_addr;
189}
190
191/* Provided by the linker */
192extern const struct kernel_symbol __start___ksymtab[];
193extern const struct kernel_symbol __stop___ksymtab[];
194extern const struct kernel_symbol __start___ksymtab_gpl[];
195extern const struct kernel_symbol __stop___ksymtab_gpl[];
196extern const struct kernel_symbol __start___ksymtab_gpl_future[];
197extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
198extern const unsigned long __start___kcrctab[];
199extern const unsigned long __start___kcrctab_gpl[];
200extern const unsigned long __start___kcrctab_gpl_future[];
201#ifdef CONFIG_UNUSED_SYMBOLS
202extern const struct kernel_symbol __start___ksymtab_unused[];
203extern const struct kernel_symbol __stop___ksymtab_unused[];
204extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
205extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
206extern const unsigned long __start___kcrctab_unused[];
207extern const unsigned long __start___kcrctab_unused_gpl[];
208#endif
209
210#ifndef CONFIG_MODVERSIONS
211#define symversion(base, idx) NULL
212#else
213#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
214#endif
215
216static bool each_symbol_in_section(const struct symsearch *arr,
217                   unsigned int arrsize,
218                   struct module *owner,
219                   bool (*fn)(const struct symsearch *syms,
220                          struct module *owner,
221                          unsigned int symnum, void *data),
222                   void *data)
223{
224    unsigned int i, j;
225
226    for (j = 0; j < arrsize; j++) {
227        for (i = 0; i < arr[j].stop - arr[j].start; i++)
228            if (fn(&arr[j], owner, i, data))
229                return true;
230    }
231
232    return false;
233}
234
235/* Returns true as soon as fn returns true, otherwise false. */
236bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
237                unsigned int symnum, void *data), void *data)
238{
239    struct module *mod;
240    static const struct symsearch arr[] = {
241        { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
242          NOT_GPL_ONLY, false },
243        { __start___ksymtab_gpl, __stop___ksymtab_gpl,
244          __start___kcrctab_gpl,
245          GPL_ONLY, false },
246        { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
247          __start___kcrctab_gpl_future,
248          WILL_BE_GPL_ONLY, false },
249#ifdef CONFIG_UNUSED_SYMBOLS
250        { __start___ksymtab_unused, __stop___ksymtab_unused,
251          __start___kcrctab_unused,
252          NOT_GPL_ONLY, true },
253        { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
254          __start___kcrctab_unused_gpl,
255          GPL_ONLY, true },
256#endif
257    };
258
259    if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
260        return true;
261
262    list_for_each_entry_rcu(mod, &modules, list) {
263        struct symsearch arr[] = {
264            { mod->syms, mod->syms + mod->num_syms, mod->crcs,
265              NOT_GPL_ONLY, false },
266            { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
267              mod->gpl_crcs,
268              GPL_ONLY, false },
269            { mod->gpl_future_syms,
270              mod->gpl_future_syms + mod->num_gpl_future_syms,
271              mod->gpl_future_crcs,
272              WILL_BE_GPL_ONLY, false },
273#ifdef CONFIG_UNUSED_SYMBOLS
274            { mod->unused_syms,
275              mod->unused_syms + mod->num_unused_syms,
276              mod->unused_crcs,
277              NOT_GPL_ONLY, true },
278            { mod->unused_gpl_syms,
279              mod->unused_gpl_syms + mod->num_unused_gpl_syms,
280              mod->unused_gpl_crcs,
281              GPL_ONLY, true },
282#endif
283        };
284
285        if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
286            return true;
287    }
288    return false;
289}
290EXPORT_SYMBOL_GPL(each_symbol);
291
292struct find_symbol_arg {
293    /* Input */
294    const char *name;
295    bool gplok;
296    bool warn;
297
298    /* Output */
299    struct module *owner;
300    const unsigned long *crc;
301    const struct kernel_symbol *sym;
302};
303
304static bool find_symbol_in_section(const struct symsearch *syms,
305                   struct module *owner,
306                   unsigned int symnum, void *data)
307{
308    struct find_symbol_arg *fsa = data;
309
310    if (strcmp(syms->start[symnum].name, fsa->name) != 0)
311        return false;
312
313    if (!fsa->gplok) {
314        if (syms->licence == GPL_ONLY)
315            return false;
316        if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
317            printk(KERN_WARNING "Symbol %s is being used "
318                   "by a non-GPL module, which will not "
319                   "be allowed in the future\n", fsa->name);
320            printk(KERN_WARNING "Please see the file "
321                   "Documentation/feature-removal-schedule.txt "
322                   "in the kernel source tree for more details.\n");
323        }
324    }
325
326#ifdef CONFIG_UNUSED_SYMBOLS
327    if (syms->unused && fsa->warn) {
328        printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
329               "however this module is using it.\n", fsa->name);
330        printk(KERN_WARNING
331               "This symbol will go away in the future.\n");
332        printk(KERN_WARNING
333               "Please evalute if this is the right api to use and if "
334               "it really is, submit a report the linux kernel "
335               "mailinglist together with submitting your code for "
336               "inclusion.\n");
337    }
338#endif
339
340    fsa->owner = owner;
341    fsa->crc = symversion(syms->crcs, symnum);
342    fsa->sym = &syms->start[symnum];
343    return true;
344}
345
346/* Find a symbol and return it, along with, (optional) crc and
347 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
348const struct kernel_symbol *find_symbol(const char *name,
349                    struct module **owner,
350                    const unsigned long **crc,
351                    bool gplok,
352                    bool warn)
353{
354    struct find_symbol_arg fsa;
355
356    fsa.name = name;
357    fsa.gplok = gplok;
358    fsa.warn = warn;
359
360    if (each_symbol(find_symbol_in_section, &fsa)) {
361        if (owner)
362            *owner = fsa.owner;
363        if (crc)
364            *crc = fsa.crc;
365        return fsa.sym;
366    }
367
368    DEBUGP("Failed to find symbol %s\n", name);
369    return NULL;
370}
371EXPORT_SYMBOL_GPL(find_symbol);
372
373/* Search for module by name: must hold module_mutex. */
374struct module *find_module(const char *name)
375{
376    struct module *mod;
377
378    list_for_each_entry(mod, &modules, list) {
379        if (strcmp(mod->name, name) == 0)
380            return mod;
381    }
382    return NULL;
383}
384EXPORT_SYMBOL_GPL(find_module);
385
386#ifdef CONFIG_SMP
387
388static inline void __percpu *mod_percpu(struct module *mod)
389{
390    return mod->percpu;
391}
392
393static int percpu_modalloc(struct module *mod,
394               unsigned long size, unsigned long align)
395{
396    if (align > PAGE_SIZE) {
397        printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
398               mod->name, align, PAGE_SIZE);
399        align = PAGE_SIZE;
400    }
401
402    mod->percpu = __alloc_reserved_percpu(size, align);
403    if (!mod->percpu) {
404        printk(KERN_WARNING
405               "%s: Could not allocate %lu bytes percpu data\n",
406               mod->name, size);
407        return -ENOMEM;
408    }
409    mod->percpu_size = size;
410    return 0;
411}
412
413static void percpu_modfree(struct module *mod)
414{
415    free_percpu(mod->percpu);
416}
417
418static unsigned int find_pcpusec(struct load_info *info)
419{
420    return find_sec(info, ".data..percpu");
421}
422
423static void percpu_modcopy(struct module *mod,
424               const void *from, unsigned long size)
425{
426    int cpu;
427
428    for_each_possible_cpu(cpu)
429        memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
430}
431
432/**
433 * is_module_percpu_address - test whether address is from module static percpu
434 * @addr: address to test
435 *
436 * Test whether @addr belongs to module static percpu area.
437 *
438 * RETURNS:
439 * %true if @addr is from module static percpu area
440 */
441bool is_module_percpu_address(unsigned long addr)
442{
443    struct module *mod;
444    unsigned int cpu;
445
446    preempt_disable();
447
448    list_for_each_entry_rcu(mod, &modules, list) {
449        if (!mod->percpu_size)
450            continue;
451        for_each_possible_cpu(cpu) {
452            void *start = per_cpu_ptr(mod->percpu, cpu);
453
454            if ((void *)addr >= start &&
455                (void *)addr < start + mod->percpu_size) {
456                preempt_enable();
457                return true;
458            }
459        }
460    }
461
462    preempt_enable();
463    return false;
464}
465
466#else /* ... !CONFIG_SMP */
467
468static inline void __percpu *mod_percpu(struct module *mod)
469{
470    return NULL;
471}
472static inline int percpu_modalloc(struct module *mod,
473                  unsigned long size, unsigned long align)
474{
475    return -ENOMEM;
476}
477static inline void percpu_modfree(struct module *mod)
478{
479}
480static unsigned int find_pcpusec(struct load_info *info)
481{
482    return 0;
483}
484static inline void percpu_modcopy(struct module *mod,
485                  const void *from, unsigned long size)
486{
487    /* pcpusec should be 0, and size of that section should be 0. */
488    BUG_ON(size != 0);
489}
490bool is_module_percpu_address(unsigned long addr)
491{
492    return false;
493}
494
495#endif /* CONFIG_SMP */
496
497#define MODINFO_ATTR(field) \
498static void setup_modinfo_##field(struct module *mod, const char *s) \
499{ \
500    mod->field = kstrdup(s, GFP_KERNEL); \
501} \
502static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
503                    struct module *mod, char *buffer) \
504{ \
505    return sprintf(buffer, "%s\n", mod->field); \
506} \
507static int modinfo_##field##_exists(struct module *mod) \
508{ \
509    return mod->field != NULL; \
510} \
511static void free_modinfo_##field(struct module *mod) \
512{ \
513    kfree(mod->field); \
514    mod->field = NULL; \
515} \
516static struct module_attribute modinfo_##field = { \
517    .attr = { .name = __stringify(field), .mode = 0444 }, \
518    .show = show_modinfo_##field, \
519    .setup = setup_modinfo_##field, \
520    .test = modinfo_##field##_exists, \
521    .free = free_modinfo_##field, \
522};
523
524MODINFO_ATTR(version);
525MODINFO_ATTR(srcversion);
526
527static char last_unloaded_module[MODULE_NAME_LEN+1];
528
529#ifdef CONFIG_MODULE_UNLOAD
530
531EXPORT_TRACEPOINT_SYMBOL(module_get);
532
533/* Init the unload section of the module. */
534static int module_unload_init(struct module *mod)
535{
536    mod->refptr = alloc_percpu(struct module_ref);
537    if (!mod->refptr)
538        return -ENOMEM;
539
540    INIT_LIST_HEAD(&mod->source_list);
541    INIT_LIST_HEAD(&mod->target_list);
542
543    /* Hold reference count during initialization. */
544    __this_cpu_write(mod->refptr->incs, 1);
545    /* Backwards compatibility macros put refcount during init. */
546    mod->waiter = current;
547
548    return 0;
549}
550
551/* Does a already use b? */
552static int already_uses(struct module *a, struct module *b)
553{
554    struct module_use *use;
555
556    list_for_each_entry(use, &b->source_list, source_list) {
557        if (use->source == a) {
558            DEBUGP("%s uses %s!\n", a->name, b->name);
559            return 1;
560        }
561    }
562    DEBUGP("%s does not use %s!\n", a->name, b->name);
563    return 0;
564}
565
566/*
567 * Module a uses b
568 * - we add 'a' as a "source", 'b' as a "target" of module use
569 * - the module_use is added to the list of 'b' sources (so
570 * 'b' can walk the list to see who sourced them), and of 'a'
571 * targets (so 'a' can see what modules it targets).
572 */
573static int add_module_usage(struct module *a, struct module *b)
574{
575    struct module_use *use;
576
577    DEBUGP("Allocating new usage for %s.\n", a->name);
578    use = kmalloc(sizeof(*use), GFP_ATOMIC);
579    if (!use) {
580        printk(KERN_WARNING "%s: out of memory loading\n", a->name);
581        return -ENOMEM;
582    }
583
584    use->source = a;
585    use->target = b;
586    list_add(&use->source_list, &b->source_list);
587    list_add(&use->target_list, &a->target_list);
588    return 0;
589}
590
591/* Module a uses b: caller needs module_mutex() */
592int ref_module(struct module *a, struct module *b)
593{
594    int err;
595
596    if (b == NULL || already_uses(a, b))
597        return 0;
598
599    /* If module isn't available, we fail. */
600    err = strong_try_module_get(b);
601    if (err)
602        return err;
603
604    err = add_module_usage(a, b);
605    if (err) {
606        module_put(b);
607        return err;
608    }
609    return 0;
610}
611EXPORT_SYMBOL_GPL(ref_module);
612
613/* Clear the unload stuff of the module. */
614static void module_unload_free(struct module *mod)
615{
616    struct module_use *use, *tmp;
617
618    mutex_lock(&module_mutex);
619    list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
620        struct module *i = use->target;
621        DEBUGP("%s unusing %s\n", mod->name, i->name);
622        module_put(i);
623        list_del(&use->source_list);
624        list_del(&use->target_list);
625        kfree(use);
626    }
627    mutex_unlock(&module_mutex);
628
629    free_percpu(mod->refptr);
630}
631
632#ifdef CONFIG_MODULE_FORCE_UNLOAD
633static inline int try_force_unload(unsigned int flags)
634{
635    int ret = (flags & O_TRUNC);
636    if (ret)
637        add_taint(TAINT_FORCED_RMMOD);
638    return ret;
639}
640#else
641static inline int try_force_unload(unsigned int flags)
642{
643    return 0;
644}
645#endif /* CONFIG_MODULE_FORCE_UNLOAD */
646
647struct stopref
648{
649    struct module *mod;
650    int flags;
651    int *forced;
652};
653
654/* Whole machine is stopped with interrupts off when this runs. */
655static int __try_stop_module(void *_sref)
656{
657    struct stopref *sref = _sref;
658
659    /* If it's not unused, quit unless we're forcing. */
660    if (module_refcount(sref->mod) != 0) {
661        if (!(*sref->forced = try_force_unload(sref->flags)))
662            return -EWOULDBLOCK;
663    }
664
665    /* Mark it as dying. */
666    sref->mod->state = MODULE_STATE_GOING;
667    return 0;
668}
669
670static int try_stop_module(struct module *mod, int flags, int *forced)
671{
672    if (flags & O_NONBLOCK) {
673        struct stopref sref = { mod, flags, forced };
674
675        return stop_machine(__try_stop_module, &sref, NULL);
676    } else {
677        /* We don't need to stop the machine for this. */
678        mod->state = MODULE_STATE_GOING;
679        synchronize_sched();
680        return 0;
681    }
682}
683
684unsigned int module_refcount(struct module *mod)
685{
686    unsigned int incs = 0, decs = 0;
687    int cpu;
688
689    for_each_possible_cpu(cpu)
690        decs += per_cpu_ptr(mod->refptr, cpu)->decs;
691    /*
692     * ensure the incs are added up after the decs.
693     * module_put ensures incs are visible before decs with smp_wmb.
694     *
695     * This 2-count scheme avoids the situation where the refcount
696     * for CPU0 is read, then CPU0 increments the module refcount,
697     * then CPU1 drops that refcount, then the refcount for CPU1 is
698     * read. We would record a decrement but not its corresponding
699     * increment so we would see a low count (disaster).
700     *
701     * Rare situation? But module_refcount can be preempted, and we
702     * might be tallying up 4096+ CPUs. So it is not impossible.
703     */
704    smp_rmb();
705    for_each_possible_cpu(cpu)
706        incs += per_cpu_ptr(mod->refptr, cpu)->incs;
707    return incs - decs;
708}
709EXPORT_SYMBOL(module_refcount);
710
711/* This exists whether we can unload or not */
712static void free_module(struct module *mod);
713
714static void wait_for_zero_refcount(struct module *mod)
715{
716    /* Since we might sleep for some time, release the mutex first */
717    mutex_unlock(&module_mutex);
718    for (;;) {
719        DEBUGP("Looking at refcount...\n");
720        set_current_state(TASK_UNINTERRUPTIBLE);
721        if (module_refcount(mod) == 0)
722            break;
723        schedule();
724    }
725    current->state = TASK_RUNNING;
726    mutex_lock(&module_mutex);
727}
728
729SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
730        unsigned int, flags)
731{
732    struct module *mod;
733    char name[MODULE_NAME_LEN];
734    int ret, forced = 0;
735
736    if (!capable(CAP_SYS_MODULE) || modules_disabled)
737        return -EPERM;
738
739    if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
740        return -EFAULT;
741    name[MODULE_NAME_LEN-1] = '\0';
742
743    if (mutex_lock_interruptible(&module_mutex) != 0)
744        return -EINTR;
745
746    mod = find_module(name);
747    if (!mod) {
748        ret = -ENOENT;
749        goto out;
750    }
751
752    if (!list_empty(&mod->source_list)) {
753        /* Other modules depend on us: get rid of them first. */
754        ret = -EWOULDBLOCK;
755        goto out;
756    }
757
758    /* Doing init or already dying? */
759    if (mod->state != MODULE_STATE_LIVE) {
760        /* FIXME: if (force), slam module count and wake up
761                   waiter --RR */
762        DEBUGP("%s already dying\n", mod->name);
763        ret = -EBUSY;
764        goto out;
765    }
766
767    /* If it has an init func, it must have an exit func to unload */
768    if (mod->init && !mod->exit) {
769        forced = try_force_unload(flags);
770        if (!forced) {
771            /* This module can't be removed */
772            ret = -EBUSY;
773            goto out;
774        }
775    }
776
777    /* Set this up before setting mod->state */
778    mod->waiter = current;
779
780    /* Stop the machine so refcounts can't move and disable module. */
781    ret = try_stop_module(mod, flags, &forced);
782    if (ret != 0)
783        goto out;
784
785    /* Never wait if forced. */
786    if (!forced && module_refcount(mod) != 0)
787        wait_for_zero_refcount(mod);
788
789    mutex_unlock(&module_mutex);
790    /* Final destruction now noone is using it. */
791    if (mod->exit != NULL)
792        mod->exit();
793    blocking_notifier_call_chain(&module_notify_list,
794                     MODULE_STATE_GOING, mod);
795    async_synchronize_full();
796
797    /* Store the name of the last unloaded module for diagnostic purposes */
798    strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
799
800    free_module(mod);
801    return 0;
802out:
803    mutex_unlock(&module_mutex);
804    return ret;
805}
806
807static inline void print_unload_info(struct seq_file *m, struct module *mod)
808{
809    struct module_use *use;
810    int printed_something = 0;
811
812    seq_printf(m, " %u ", module_refcount(mod));
813
814    /* Always include a trailing , so userspace can differentiate
815           between this and the old multi-field proc format. */
816    list_for_each_entry(use, &mod->source_list, source_list) {
817        printed_something = 1;
818        seq_printf(m, "%s,", use->source->name);
819    }
820
821    if (mod->init != NULL && mod->exit == NULL) {
822        printed_something = 1;
823        seq_printf(m, "[permanent],");
824    }
825
826    if (!printed_something)
827        seq_printf(m, "-");
828}
829
830void __symbol_put(const char *symbol)
831{
832    struct module *owner;
833
834    preempt_disable();
835    if (!find_symbol(symbol, &owner, NULL, true, false))
836        BUG();
837    module_put(owner);
838    preempt_enable();
839}
840EXPORT_SYMBOL(__symbol_put);
841
842/* Note this assumes addr is a function, which it currently always is. */
843void symbol_put_addr(void *addr)
844{
845    struct module *modaddr;
846    unsigned long a = (unsigned long)dereference_function_descriptor(addr);
847
848    if (core_kernel_text(a))
849        return;
850
851    /* module_text_address is safe here: we're supposed to have reference
852     * to module from symbol_get, so it can't go away. */
853    modaddr = __module_text_address(a);
854    BUG_ON(!modaddr);
855    module_put(modaddr);
856}
857EXPORT_SYMBOL_GPL(symbol_put_addr);
858
859static ssize_t show_refcnt(struct module_attribute *mattr,
860               struct module *mod, char *buffer)
861{
862    return sprintf(buffer, "%u\n", module_refcount(mod));
863}
864
865static struct module_attribute refcnt = {
866    .attr = { .name = "refcnt", .mode = 0444 },
867    .show = show_refcnt,
868};
869
870void module_put(struct module *module)
871{
872    if (module) {
873        preempt_disable();
874        smp_wmb(); /* see comment in module_refcount */
875        __this_cpu_inc(module->refptr->decs);
876
877        trace_module_put(module, _RET_IP_);
878        /* Maybe they're waiting for us to drop reference? */
879        if (unlikely(!module_is_live(module)))
880            wake_up_process(module->waiter);
881        preempt_enable();
882    }
883}
884EXPORT_SYMBOL(module_put);
885
886#else /* !CONFIG_MODULE_UNLOAD */
887static inline void print_unload_info(struct seq_file *m, struct module *mod)
888{
889    /* We don't know the usage count, or what modules are using. */
890    seq_printf(m, " - -");
891}
892
893static inline void module_unload_free(struct module *mod)
894{
895}
896
897int ref_module(struct module *a, struct module *b)
898{
899    return strong_try_module_get(b);
900}
901EXPORT_SYMBOL_GPL(ref_module);
902
903static inline int module_unload_init(struct module *mod)
904{
905    return 0;
906}
907#endif /* CONFIG_MODULE_UNLOAD */
908
909static ssize_t show_initstate(struct module_attribute *mattr,
910               struct module *mod, char *buffer)
911{
912    const char *state = "unknown";
913
914    switch (mod->state) {
915    case MODULE_STATE_LIVE:
916        state = "live";
917        break;
918    case MODULE_STATE_COMING:
919        state = "coming";
920        break;
921    case MODULE_STATE_GOING:
922        state = "going";
923        break;
924    }
925    return sprintf(buffer, "%s\n", state);
926}
927
928static struct module_attribute initstate = {
929    .attr = { .name = "initstate", .mode = 0444 },
930    .show = show_initstate,
931};
932
933static struct module_attribute *modinfo_attrs[] = {
934    &modinfo_version,
935    &modinfo_srcversion,
936    &initstate,
937#ifdef CONFIG_MODULE_UNLOAD
938    &refcnt,
939#endif
940    NULL,
941};
942
943static const char vermagic[] = VERMAGIC_STRING;
944
945static int try_to_force_load(struct module *mod, const char *reason)
946{
947#ifdef CONFIG_MODULE_FORCE_LOAD
948    if (!test_taint(TAINT_FORCED_MODULE))
949        printk(KERN_WARNING "%s: %s: kernel tainted.\n",
950               mod->name, reason);
951    add_taint_module(mod, TAINT_FORCED_MODULE);
952    return 0;
953#else
954    return -ENOEXEC;
955#endif
956}
957
958#ifdef CONFIG_MODVERSIONS
959/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
960static unsigned long maybe_relocated(unsigned long crc,
961                     const struct module *crc_owner)
962{
963#ifdef ARCH_RELOCATES_KCRCTAB
964    if (crc_owner == NULL)
965        return crc - (unsigned long)reloc_start;
966#endif
967    return crc;
968}
969
970static int check_version(Elf_Shdr *sechdrs,
971             unsigned int versindex,
972             const char *symname,
973             struct module *mod,
974             const unsigned long *crc,
975             const struct module *crc_owner)
976{
977    unsigned int i, num_versions;
978    struct modversion_info *versions;
979
980    /* Exporting module didn't supply crcs? OK, we're already tainted. */
981    if (!crc)
982        return 1;
983
984    /* No versions at all? modprobe --force does this. */
985    if (versindex == 0)
986        return try_to_force_load(mod, symname) == 0;
987
988    versions = (void *) sechdrs[versindex].sh_addr;
989    num_versions = sechdrs[versindex].sh_size
990        / sizeof(struct modversion_info);
991
992    for (i = 0; i < num_versions; i++) {
993        if (strcmp(versions[i].name, symname) != 0)
994            continue;
995
996        if (versions[i].crc == maybe_relocated(*crc, crc_owner))
997            return 1;
998        DEBUGP("Found checksum %lX vs module %lX\n",
999               maybe_relocated(*crc, crc_owner), versions[i].crc);
1000        goto bad_version;
1001    }
1002
1003    printk(KERN_WARNING "%s: no symbol version for %s\n",
1004           mod->name, symname);
1005    return 0;
1006
1007bad_version:
1008    printk("%s: disagrees about version of symbol %s\n",
1009           mod->name, symname);
1010    return 0;
1011}
1012
1013static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1014                      unsigned int versindex,
1015                      struct module *mod)
1016{
1017    const unsigned long *crc;
1018
1019    /* Since this should be found in kernel (which can't be removed),
1020     * no locking is necessary. */
1021    if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1022             &crc, true, false))
1023        BUG();
1024    return check_version(sechdrs, versindex, "module_layout", mod, crc,
1025                 NULL);
1026}
1027
1028/* First part is kernel version, which we ignore if module has crcs. */
1029static inline int same_magic(const char *amagic, const char *bmagic,
1030                 bool has_crcs)
1031{
1032    if (has_crcs) {
1033        amagic += strcspn(amagic, " ");
1034        bmagic += strcspn(bmagic, " ");
1035    }
1036    return strcmp(amagic, bmagic) == 0;
1037}
1038#else
1039static inline int check_version(Elf_Shdr *sechdrs,
1040                unsigned int versindex,
1041                const char *symname,
1042                struct module *mod,
1043                const unsigned long *crc,
1044                const struct module *crc_owner)
1045{
1046    return 1;
1047}
1048
1049static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1050                      unsigned int versindex,
1051                      struct module *mod)
1052{
1053    return 1;
1054}
1055
1056static inline int same_magic(const char *amagic, const char *bmagic,
1057                 bool has_crcs)
1058{
1059    return strcmp(amagic, bmagic) == 0;
1060}
1061#endif /* CONFIG_MODVERSIONS */
1062
1063/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1064static const struct kernel_symbol *resolve_symbol(struct module *mod,
1065                          const struct load_info *info,
1066                          const char *name,
1067                          char ownername[])
1068{
1069    struct module *owner;
1070    const struct kernel_symbol *sym;
1071    const unsigned long *crc;
1072    int err;
1073
1074    mutex_lock(&module_mutex);
1075    sym = find_symbol(name, &owner, &crc,
1076              !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1077    if (!sym)
1078        goto unlock;
1079
1080    if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1081               owner)) {
1082        sym = ERR_PTR(-EINVAL);
1083        goto getname;
1084    }
1085
1086    err = ref_module(mod, owner);
1087    if (err) {
1088        sym = ERR_PTR(err);
1089        goto getname;
1090    }
1091
1092getname:
1093    /* We must make copy under the lock if we failed to get ref. */
1094    strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1095unlock:
1096    mutex_unlock(&module_mutex);
1097    return sym;
1098}
1099
1100static const struct kernel_symbol *
1101resolve_symbol_wait(struct module *mod,
1102            const struct load_info *info,
1103            const char *name)
1104{
1105    const struct kernel_symbol *ksym;
1106    char owner[MODULE_NAME_LEN];
1107
1108    if (wait_event_interruptible_timeout(module_wq,
1109            !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1110            || PTR_ERR(ksym) != -EBUSY,
1111                         30 * HZ) <= 0) {
1112        printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1113               mod->name, owner);
1114    }
1115    return ksym;
1116}
1117
1118/*
1119 * /sys/module/foo/sections stuff
1120 * J. Corbet <corbet@lwn.net>
1121 */
1122#ifdef CONFIG_SYSFS
1123
1124#ifdef CONFIG_KALLSYMS
1125static inline bool sect_empty(const Elf_Shdr *sect)
1126{
1127    return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1128}
1129
1130struct module_sect_attr
1131{
1132    struct module_attribute mattr;
1133    char *name;
1134    unsigned long address;
1135};
1136
1137struct module_sect_attrs
1138{
1139    struct attribute_group grp;
1140    unsigned int nsections;
1141    struct module_sect_attr attrs[0];
1142};
1143
1144static ssize_t module_sect_show(struct module_attribute *mattr,
1145                struct module *mod, char *buf)
1146{
1147    struct module_sect_attr *sattr =
1148        container_of(mattr, struct module_sect_attr, mattr);
1149    return sprintf(buf, "0x%lx\n", sattr->address);
1150}
1151
1152static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1153{
1154    unsigned int section;
1155
1156    for (section = 0; section < sect_attrs->nsections; section++)
1157        kfree(sect_attrs->attrs[section].name);
1158    kfree(sect_attrs);
1159}
1160
1161static void add_sect_attrs(struct module *mod, const struct load_info *info)
1162{
1163    unsigned int nloaded = 0, i, size[2];
1164    struct module_sect_attrs *sect_attrs;
1165    struct module_sect_attr *sattr;
1166    struct attribute **gattr;
1167
1168    /* Count loaded sections and allocate structures */
1169    for (i = 0; i < info->hdr->e_shnum; i++)
1170        if (!sect_empty(&info->sechdrs[i]))
1171            nloaded++;
1172    size[0] = ALIGN(sizeof(*sect_attrs)
1173            + nloaded * sizeof(sect_attrs->attrs[0]),
1174            sizeof(sect_attrs->grp.attrs[0]));
1175    size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1176    sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1177    if (sect_attrs == NULL)
1178        return;
1179
1180    /* Setup section attributes. */
1181    sect_attrs->grp.name = "sections";
1182    sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1183
1184    sect_attrs->nsections = 0;
1185    sattr = &sect_attrs->attrs[0];
1186    gattr = &sect_attrs->grp.attrs[0];
1187    for (i = 0; i < info->hdr->e_shnum; i++) {
1188        Elf_Shdr *sec = &info->sechdrs[i];
1189        if (sect_empty(sec))
1190            continue;
1191        sattr->address = sec->sh_addr;
1192        sattr->name = kstrdup(info->secstrings + sec->sh_name,
1193                    GFP_KERNEL);
1194        if (sattr->name == NULL)
1195            goto out;
1196        sect_attrs->nsections++;
1197        sysfs_attr_init(&sattr->mattr.attr);
1198        sattr->mattr.show = module_sect_show;
1199        sattr->mattr.store = NULL;
1200        sattr->mattr.attr.name = sattr->name;
1201        sattr->mattr.attr.mode = S_IRUGO;
1202        *(gattr++) = &(sattr++)->mattr.attr;
1203    }
1204    *gattr = NULL;
1205
1206    if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1207        goto out;
1208
1209    mod->sect_attrs = sect_attrs;
1210    return;
1211  out:
1212    free_sect_attrs(sect_attrs);
1213}
1214
1215static void remove_sect_attrs(struct module *mod)
1216{
1217    if (mod->sect_attrs) {
1218        sysfs_remove_group(&mod->mkobj.kobj,
1219                   &mod->sect_attrs->grp);
1220        /* We are positive that no one is using any sect attrs
1221         * at this point. Deallocate immediately. */
1222        free_sect_attrs(mod->sect_attrs);
1223        mod->sect_attrs = NULL;
1224    }
1225}
1226
1227/*
1228 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1229 */
1230
1231struct module_notes_attrs {
1232    struct kobject *dir;
1233    unsigned int notes;
1234    struct bin_attribute attrs[0];
1235};
1236
1237static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1238                 struct bin_attribute *bin_attr,
1239                 char *buf, loff_t pos, size_t count)
1240{
1241    /*
1242     * The caller checked the pos and count against our size.
1243     */
1244    memcpy(buf, bin_attr->private + pos, count);
1245    return count;
1246}
1247
1248static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1249                 unsigned int i)
1250{
1251    if (notes_attrs->dir) {
1252        while (i-- > 0)
1253            sysfs_remove_bin_file(notes_attrs->dir,
1254                          &notes_attrs->attrs[i]);
1255        kobject_put(notes_attrs->dir);
1256    }
1257    kfree(notes_attrs);
1258}
1259
1260static void add_notes_attrs(struct module *mod, const struct load_info *info)
1261{
1262    unsigned int notes, loaded, i;
1263    struct module_notes_attrs *notes_attrs;
1264    struct bin_attribute *nattr;
1265
1266    /* failed to create section attributes, so can't create notes */
1267    if (!mod->sect_attrs)
1268        return;
1269
1270    /* Count notes sections and allocate structures. */
1271    notes = 0;
1272    for (i = 0; i < info->hdr->e_shnum; i++)
1273        if (!sect_empty(&info->sechdrs[i]) &&
1274            (info->sechdrs[i].sh_type == SHT_NOTE))
1275            ++notes;
1276
1277    if (notes == 0)
1278        return;
1279
1280    notes_attrs = kzalloc(sizeof(*notes_attrs)
1281                  + notes * sizeof(notes_attrs->attrs[0]),
1282                  GFP_KERNEL);
1283    if (notes_attrs == NULL)
1284        return;
1285
1286    notes_attrs->notes = notes;
1287    nattr = &notes_attrs->attrs[0];
1288    for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1289        if (sect_empty(&info->sechdrs[i]))
1290            continue;
1291        if (info->sechdrs[i].sh_type == SHT_NOTE) {
1292            sysfs_bin_attr_init(nattr);
1293            nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1294            nattr->attr.mode = S_IRUGO;
1295            nattr->size = info->sechdrs[i].sh_size;
1296            nattr->private = (void *) info->sechdrs[i].sh_addr;
1297            nattr->read = module_notes_read;
1298            ++nattr;
1299        }
1300        ++loaded;
1301    }
1302
1303    notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1304    if (!notes_attrs->dir)
1305        goto out;
1306
1307    for (i = 0; i < notes; ++i)
1308        if (sysfs_create_bin_file(notes_attrs->dir,
1309                      &notes_attrs->attrs[i]))
1310            goto out;
1311
1312    mod->notes_attrs = notes_attrs;
1313    return;
1314
1315  out:
1316    free_notes_attrs(notes_attrs, i);
1317}
1318
1319static void remove_notes_attrs(struct module *mod)
1320{
1321    if (mod->notes_attrs)
1322        free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1323}
1324
1325#else
1326
1327static inline void add_sect_attrs(struct module *mod,
1328                  const struct load_info *info)
1329{
1330}
1331
1332static inline void remove_sect_attrs(struct module *mod)
1333{
1334}
1335
1336static inline void add_notes_attrs(struct module *mod,
1337                   const struct load_info *info)
1338{
1339}
1340
1341static inline void remove_notes_attrs(struct module *mod)
1342{
1343}
1344#endif /* CONFIG_KALLSYMS */
1345
1346static void add_usage_links(struct module *mod)
1347{
1348#ifdef CONFIG_MODULE_UNLOAD
1349    struct module_use *use;
1350    int nowarn;
1351
1352    mutex_lock(&module_mutex);
1353    list_for_each_entry(use, &mod->target_list, target_list) {
1354        nowarn = sysfs_create_link(use->target->holders_dir,
1355                       &mod->mkobj.kobj, mod->name);
1356    }
1357    mutex_unlock(&module_mutex);
1358#endif
1359}
1360
1361static void del_usage_links(struct module *mod)
1362{
1363#ifdef CONFIG_MODULE_UNLOAD
1364    struct module_use *use;
1365
1366    mutex_lock(&module_mutex);
1367    list_for_each_entry(use, &mod->target_list, target_list)
1368        sysfs_remove_link(use->target->holders_dir, mod->name);
1369    mutex_unlock(&module_mutex);
1370#endif
1371}
1372
1373static int module_add_modinfo_attrs(struct module *mod)
1374{
1375    struct module_attribute *attr;
1376    struct module_attribute *temp_attr;
1377    int error = 0;
1378    int i;
1379
1380    mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1381                    (ARRAY_SIZE(modinfo_attrs) + 1)),
1382                    GFP_KERNEL);
1383    if (!mod->modinfo_attrs)
1384        return -ENOMEM;
1385
1386    temp_attr = mod->modinfo_attrs;
1387    for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1388        if (!attr->test ||
1389            (attr->test && attr->test(mod))) {
1390            memcpy(temp_attr, attr, sizeof(*temp_attr));
1391            sysfs_attr_init(&temp_attr->attr);
1392            error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1393            ++temp_attr;
1394        }
1395    }
1396    return error;
1397}
1398
1399static void module_remove_modinfo_attrs(struct module *mod)
1400{
1401    struct module_attribute *attr;
1402    int i;
1403
1404    for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1405        /* pick a field to test for end of list */
1406        if (!attr->attr.name)
1407            break;
1408        sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1409        if (attr->free)
1410            attr->free(mod);
1411    }
1412    kfree(mod->modinfo_attrs);
1413}
1414
1415static int mod_sysfs_init(struct module *mod)
1416{
1417    int err;
1418    struct kobject *kobj;
1419
1420    if (!module_sysfs_initialized) {
1421        printk(KERN_ERR "%s: module sysfs not initialized\n",
1422               mod->name);
1423        err = -EINVAL;
1424        goto out;
1425    }
1426
1427    kobj = kset_find_obj(module_kset, mod->name);
1428    if (kobj) {
1429        printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1430        kobject_put(kobj);
1431        err = -EINVAL;
1432        goto out;
1433    }
1434
1435    mod->mkobj.mod = mod;
1436
1437    memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1438    mod->mkobj.kobj.kset = module_kset;
1439    err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1440                   "%s", mod->name);
1441    if (err)
1442        kobject_put(&mod->mkobj.kobj);
1443
1444    /* delay uevent until full sysfs population */
1445out:
1446    return err;
1447}
1448
1449static int mod_sysfs_setup(struct module *mod,
1450               const struct load_info *info,
1451               struct kernel_param *kparam,
1452               unsigned int num_params)
1453{
1454    int err;
1455
1456    err = mod_sysfs_init(mod);
1457    if (err)
1458        goto out;
1459
1460    mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1461    if (!mod->holders_dir) {
1462        err = -ENOMEM;
1463        goto out_unreg;
1464    }
1465
1466    err = module_param_sysfs_setup(mod, kparam, num_params);
1467    if (err)
1468        goto out_unreg_holders;
1469
1470    err = module_add_modinfo_attrs(mod);
1471    if (err)
1472        goto out_unreg_param;
1473
1474    add_usage_links(mod);
1475    add_sect_attrs(mod, info);
1476    add_notes_attrs(mod, info);
1477
1478    kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1479    return 0;
1480
1481out_unreg_param:
1482    module_param_sysfs_remove(mod);
1483out_unreg_holders:
1484    kobject_put(mod->holders_dir);
1485out_unreg:
1486    kobject_put(&mod->mkobj.kobj);
1487out:
1488    return err;
1489}
1490
1491static void mod_sysfs_fini(struct module *mod)
1492{
1493    remove_notes_attrs(mod);
1494    remove_sect_attrs(mod);
1495    kobject_put(&mod->mkobj.kobj);
1496}
1497
1498#else /* !CONFIG_SYSFS */
1499
1500static int mod_sysfs_setup(struct module *mod,
1501               const struct load_info *info,
1502               struct kernel_param *kparam,
1503               unsigned int num_params)
1504{
1505    return 0;
1506}
1507
1508static void mod_sysfs_fini(struct module *mod)
1509{
1510}
1511
1512static void module_remove_modinfo_attrs(struct module *mod)
1513{
1514}
1515
1516static void del_usage_links(struct module *mod)
1517{
1518}
1519
1520#endif /* CONFIG_SYSFS */
1521
1522static void mod_sysfs_teardown(struct module *mod)
1523{
1524    del_usage_links(mod);
1525    module_remove_modinfo_attrs(mod);
1526    module_param_sysfs_remove(mod);
1527    kobject_put(mod->mkobj.drivers_dir);
1528    kobject_put(mod->holders_dir);
1529    mod_sysfs_fini(mod);
1530}
1531
1532/*
1533 * unlink the module with the whole machine is stopped with interrupts off
1534 * - this defends against kallsyms not taking locks
1535 */
1536static int __unlink_module(void *_mod)
1537{
1538    struct module *mod = _mod;
1539    list_del(&mod->list);
1540    module_bug_cleanup(mod);
1541    return 0;
1542}
1543
1544/* Free a module, remove from lists, etc. */
1545static void free_module(struct module *mod)
1546{
1547    trace_module_free(mod);
1548
1549    /* Delete from various lists */
1550    mutex_lock(&module_mutex);
1551    stop_machine(__unlink_module, mod, NULL);
1552    mutex_unlock(&module_mutex);
1553    mod_sysfs_teardown(mod);
1554
1555    /* Remove dynamic debug info */
1556    ddebug_remove_module(mod->name);
1557
1558    /* Arch-specific cleanup. */
1559    module_arch_cleanup(mod);
1560
1561    /* Module unload stuff */
1562    module_unload_free(mod);
1563
1564    /* Free any allocated parameters. */
1565    destroy_params(mod->kp, mod->num_kp);
1566
1567    /* This may be NULL, but that's OK */
1568    module_free(mod, mod->module_init);
1569    kfree(mod->args);
1570    percpu_modfree(mod);
1571
1572    /* Free lock-classes: */
1573    lockdep_free_key_range(mod->module_core, mod->core_size);
1574
1575    /* Finally, free the core (containing the module structure) */
1576    module_free(mod, mod->module_core);
1577
1578#ifdef CONFIG_MPU
1579    update_protections(current->mm);
1580#endif
1581}
1582
1583void *__symbol_get(const char *symbol)
1584{
1585    struct module *owner;
1586    const struct kernel_symbol *sym;
1587
1588    preempt_disable();
1589    sym = find_symbol(symbol, &owner, NULL, true, true);
1590    if (sym && strong_try_module_get(owner))
1591        sym = NULL;
1592    preempt_enable();
1593
1594    return sym ? (void *)sym->value : NULL;
1595}
1596EXPORT_SYMBOL_GPL(__symbol_get);
1597
1598/*
1599 * Ensure that an exported symbol [global namespace] does not already exist
1600 * in the kernel or in some other module's exported symbol table.
1601 *
1602 * You must hold the module_mutex.
1603 */
1604static int verify_export_symbols(struct module *mod)
1605{
1606    unsigned int i;
1607    struct module *owner;
1608    const struct kernel_symbol *s;
1609    struct {
1610        const struct kernel_symbol *sym;
1611        unsigned int num;
1612    } arr[] = {
1613        { mod->syms, mod->num_syms },
1614        { mod->gpl_syms, mod->num_gpl_syms },
1615        { mod->gpl_future_syms, mod->num_gpl_future_syms },
1616#ifdef CONFIG_UNUSED_SYMBOLS
1617        { mod->unused_syms, mod->num_unused_syms },
1618        { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1619#endif
1620    };
1621
1622    for (i = 0; i < ARRAY_SIZE(arr); i++) {
1623        for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1624            if (find_symbol(s->name, &owner, NULL, true, false)) {
1625                printk(KERN_ERR
1626                       "%s: exports duplicate symbol %s"
1627                       " (owned by %s)\n",
1628                       mod->name, s->name, module_name(owner));
1629                return -ENOEXEC;
1630            }
1631        }
1632    }
1633    return 0;
1634}
1635
1636/* Change all symbols so that st_value encodes the pointer directly. */
1637static int simplify_symbols(struct module *mod, const struct load_info *info)
1638{
1639    Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1640    Elf_Sym *sym = (void *)symsec->sh_addr;
1641    unsigned long secbase;
1642    unsigned int i;
1643    int ret = 0;
1644    const struct kernel_symbol *ksym;
1645
1646    for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1647        const char *name = info->strtab + sym[i].st_name;
1648
1649        switch (sym[i].st_shndx) {
1650        case SHN_COMMON:
1651            /* We compiled with -fno-common. These are not
1652               supposed to happen. */
1653            DEBUGP("Common symbol: %s\n", name);
1654            printk("%s: please compile with -fno-common\n",
1655                   mod->name);
1656            ret = -ENOEXEC;
1657            break;
1658
1659        case SHN_ABS:
1660            /* Don't need to do anything */
1661            DEBUGP("Absolute symbol: 0x%08lx\n",
1662                   (long)sym[i].st_value);
1663            break;
1664
1665        case SHN_UNDEF:
1666            ksym = resolve_symbol_wait(mod, info, name);
1667            /* Ok if resolved. */
1668            if (ksym && !IS_ERR(ksym)) {
1669                sym[i].st_value = ksym->value;
1670                break;
1671            }
1672
1673            /* Ok if weak. */
1674            if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1675                break;
1676
1677            printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1678                   mod->name, name, PTR_ERR(ksym));
1679            ret = PTR_ERR(ksym) ?: -ENOENT;
1680            break;
1681
1682        default:
1683            /* Divert to percpu allocation if a percpu var. */
1684            if (sym[i].st_shndx == info->index.pcpu)
1685                secbase = (unsigned long)mod_percpu(mod);
1686            else
1687                secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1688            sym[i].st_value += secbase;
1689            break;
1690        }
1691    }
1692
1693    return ret;
1694}
1695
1696static int apply_relocations(struct module *mod, const struct load_info *info)
1697{
1698    unsigned int i;
1699    int err = 0;
1700
1701    /* Now do relocations. */
1702    for (i = 1; i < info->hdr->e_shnum; i++) {
1703        unsigned int infosec = info->sechdrs[i].sh_info;
1704
1705        /* Not a valid relocation section? */
1706        if (infosec >= info->hdr->e_shnum)
1707            continue;
1708
1709        /* Don't bother with non-allocated sections */
1710        if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1711            continue;
1712
1713        if (info->sechdrs[i].sh_type == SHT_REL)
1714            err = apply_relocate(info->sechdrs, info->strtab,
1715                         info->index.sym, i, mod);
1716        else if (info->sechdrs[i].sh_type == SHT_RELA)
1717            err = apply_relocate_add(info->sechdrs, info->strtab,
1718                         info->index.sym, i, mod);
1719        if (err < 0)
1720            break;
1721    }
1722    return err;
1723}
1724
1725/* Additional bytes needed by arch in front of individual sections */
1726unsigned int __weak arch_mod_section_prepend(struct module *mod,
1727                         unsigned int section)
1728{
1729    /* default implementation just returns zero */
1730    return 0;
1731}
1732
1733/* Update size with this section: return offset. */
1734static long get_offset(struct module *mod, unsigned int *size,
1735               Elf_Shdr *sechdr, unsigned int section)
1736{
1737    long ret;
1738
1739    *size += arch_mod_section_prepend(mod, section);
1740    ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1741    *size = ret + sechdr->sh_size;
1742    return ret;
1743}
1744
1745/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1746   might -- code, read-only data, read-write data, small data. Tally
1747   sizes, and place the offsets into sh_entsize fields: high bit means it
1748   belongs in init. */
1749static void layout_sections(struct module *mod, struct load_info *info)
1750{
1751    static unsigned long const masks[][2] = {
1752        /* NOTE: all executable code must be the first section
1753         * in this array; otherwise modify the text_size
1754         * finder in the two loops below */
1755        { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1756        { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1757        { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1758        { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1759    };
1760    unsigned int m, i;
1761
1762    for (i = 0; i < info->hdr->e_shnum; i++)
1763        info->sechdrs[i].sh_entsize = ~0UL;
1764
1765    DEBUGP("Core section allocation order:\n");
1766    for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1767        for (i = 0; i < info->hdr->e_shnum; ++i) {
1768            Elf_Shdr *s = &info->sechdrs[i];
1769            const char *sname = info->secstrings + s->sh_name;
1770
1771            if ((s->sh_flags & masks[m][0]) != masks[m][0]
1772                || (s->sh_flags & masks[m][1])
1773                || s->sh_entsize != ~0UL
1774                || strstarts(sname, ".init"))
1775                continue;
1776            s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
1777            DEBUGP("\t%s\n", name);
1778        }
1779        if (m == 0)
1780            mod->core_text_size = mod->core_size;
1781    }
1782
1783    DEBUGP("Init section allocation order:\n");
1784    for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1785        for (i = 0; i < info->hdr->e_shnum; ++i) {
1786            Elf_Shdr *s = &info->sechdrs[i];
1787            const char *sname = info->secstrings + s->sh_name;
1788
1789            if ((s->sh_flags & masks[m][0]) != masks[m][0]
1790                || (s->sh_flags & masks[m][1])
1791                || s->sh_entsize != ~0UL
1792                || !strstarts(sname, ".init"))
1793                continue;
1794            s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
1795                     | INIT_OFFSET_MASK);
1796            DEBUGP("\t%s\n", sname);
1797        }
1798        if (m == 0)
1799            mod->init_text_size = mod->init_size;
1800    }
1801}
1802
1803static void set_license(struct module *mod, const char *license)
1804{
1805    if (!license)
1806        license = "unspecified";
1807
1808    if (!license_is_gpl_compatible(license)) {
1809        if (!test_taint(TAINT_PROPRIETARY_MODULE))
1810            printk(KERN_WARNING "%s: module license '%s' taints "
1811                "kernel.\n", mod->name, license);
1812        add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1813    }
1814}
1815
1816/* Parse tag=value strings from .modinfo section */
1817static char *next_string(char *string, unsigned long *secsize)
1818{
1819    /* Skip non-zero chars */
1820    while (string[0]) {
1821        string++;
1822        if ((*secsize)-- <= 1)
1823            return NULL;
1824    }
1825
1826    /* Skip any zero padding. */
1827    while (!string[0]) {
1828        string++;
1829        if ((*secsize)-- <= 1)
1830            return NULL;
1831    }
1832    return string;
1833}
1834
1835static char *get_modinfo(struct load_info *info, const char *tag)
1836{
1837    char *p;
1838    unsigned int taglen = strlen(tag);
1839    Elf_Shdr *infosec = &info->sechdrs[info->index.info];
1840    unsigned long size = infosec->sh_size;
1841
1842    for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
1843        if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1844            return p + taglen + 1;
1845    }
1846    return NULL;
1847}
1848
1849static void setup_modinfo(struct module *mod, struct load_info *info)
1850{
1851    struct module_attribute *attr;
1852    int i;
1853
1854    for (i = 0; (attr = modinfo_attrs[i]); i++) {
1855        if (attr->setup)
1856            attr->setup(mod, get_modinfo(info, attr->attr.name));
1857    }
1858}
1859
1860static void free_modinfo(struct module *mod)
1861{
1862    struct module_attribute *attr;
1863    int i;
1864
1865    for (i = 0; (attr = modinfo_attrs[i]); i++) {
1866        if (attr->free)
1867            attr->free(mod);
1868    }
1869}
1870
1871#ifdef CONFIG_KALLSYMS
1872
1873/* lookup symbol in given range of kernel_symbols */
1874static const struct kernel_symbol *lookup_symbol(const char *name,
1875    const struct kernel_symbol *start,
1876    const struct kernel_symbol *stop)
1877{
1878    const struct kernel_symbol *ks = start;
1879    for (; ks < stop; ks++)
1880        if (strcmp(ks->name, name) == 0)
1881            return ks;
1882    return NULL;
1883}
1884
1885static int is_exported(const char *name, unsigned long value,
1886               const struct module *mod)
1887{
1888    const struct kernel_symbol *ks;
1889    if (!mod)
1890        ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
1891    else
1892        ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
1893    return ks != NULL && ks->value == value;
1894}
1895
1896/* As per nm */
1897static char elf_type(const Elf_Sym *sym, const struct load_info *info)
1898{
1899    const Elf_Shdr *sechdrs = info->sechdrs;
1900
1901    if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1902        if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1903            return 'v';
1904        else
1905            return 'w';
1906    }
1907    if (sym->st_shndx == SHN_UNDEF)
1908        return 'U';
1909    if (sym->st_shndx == SHN_ABS)
1910        return 'a';
1911    if (sym->st_shndx >= SHN_LORESERVE)
1912        return '?';
1913    if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1914        return 't';
1915    if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1916        && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1917        if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1918            return 'r';
1919        else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1920            return 'g';
1921        else
1922            return 'd';
1923    }
1924    if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1925        if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1926            return 's';
1927        else
1928            return 'b';
1929    }
1930    if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
1931              ".debug")) {
1932        return 'n';
1933    }
1934    return '?';
1935}
1936
1937static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
1938                           unsigned int shnum)
1939{
1940    const Elf_Shdr *sec;
1941
1942    if (src->st_shndx == SHN_UNDEF
1943        || src->st_shndx >= shnum
1944        || !src->st_name)
1945        return false;
1946
1947    sec = sechdrs + src->st_shndx;
1948    if (!(sec->sh_flags & SHF_ALLOC)
1949#ifndef CONFIG_KALLSYMS_ALL
1950        || !(sec->sh_flags & SHF_EXECINSTR)
1951#endif
1952        || (sec->sh_entsize & INIT_OFFSET_MASK))
1953        return false;
1954
1955    return true;
1956}
1957
1958static void layout_symtab(struct module *mod, struct load_info *info)
1959{
1960    Elf_Shdr *symsect = info->sechdrs + info->index.sym;
1961    Elf_Shdr *strsect = info->sechdrs + info->index.str;
1962    const Elf_Sym *src;
1963    unsigned int i, nsrc, ndst;
1964
1965    /* Put symbol section at end of init part of module. */
1966    symsect->sh_flags |= SHF_ALLOC;
1967    symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
1968                     info->index.sym) | INIT_OFFSET_MASK;
1969    DEBUGP("\t%s\n", info->secstrings + symsect->sh_name);
1970
1971    src = (void *)info->hdr + symsect->sh_offset;
1972    nsrc = symsect->sh_size / sizeof(*src);
1973    for (ndst = i = 1; i < nsrc; ++i, ++src)
1974        if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
1975            unsigned int j = src->st_name;
1976
1977            while (!__test_and_set_bit(j, info->strmap)
1978                   && info->strtab[j])
1979                ++j;
1980            ++ndst;
1981        }
1982
1983    /* Append room for core symbols at end of core part. */
1984    info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
1985    mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
1986
1987    /* Put string table section at end of init part of module. */
1988    strsect->sh_flags |= SHF_ALLOC;
1989    strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
1990                     info->index.str) | INIT_OFFSET_MASK;
1991    DEBUGP("\t%s\n", info->secstrings + strsect->sh_name);
1992
1993    /* Append room for core symbols' strings at end of core part. */
1994    info->stroffs = mod->core_size;
1995    __set_bit(0, info->strmap);
1996    mod->core_size += bitmap_weight(info->strmap, strsect->sh_size);
1997}
1998
1999static void add_kallsyms(struct module *mod, const struct load_info *info)
2000{
2001    unsigned int i, ndst;
2002    const Elf_Sym *src;
2003    Elf_Sym *dst;
2004    char *s;
2005    Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2006
2007    mod->symtab = (void *)symsec->sh_addr;
2008    mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2009    /* Make sure we get permanent strtab: don't use info->strtab. */
2010    mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2011
2012    /* Set types up while we still have access to sections. */
2013    for (i = 0; i < mod->num_symtab; i++)
2014        mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2015
2016    mod->core_symtab = dst = mod->module_core + info->symoffs;
2017    src = mod->symtab;
2018    *dst = *src;
2019    for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2020        if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2021            continue;
2022        dst[ndst] = *src;
2023        dst[ndst].st_name = bitmap_weight(info->strmap,
2024                          dst[ndst].st_name);
2025        ++ndst;
2026    }
2027    mod->core_num_syms = ndst;
2028
2029    mod->core_strtab = s = mod->module_core + info->stroffs;
2030    for (*s = 0, i = 1; i < info->sechdrs[info->index.str].sh_size; ++i)
2031        if (test_bit(i, info->strmap))
2032            *++s = mod->strtab[i];
2033}
2034#else
2035static inline void layout_symtab(struct module *mod, struct load_info *info)
2036{
2037}
2038
2039static void add_kallsyms(struct module *mod, struct load_info *info)
2040{
2041}
2042#endif /* CONFIG_KALLSYMS */
2043
2044static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2045{
2046    if (!debug)
2047        return;
2048#ifdef CONFIG_DYNAMIC_DEBUG
2049    if (ddebug_add_module(debug, num, debug->modname))
2050        printk(KERN_ERR "dynamic debug error adding module: %s\n",
2051                    debug->modname);
2052#endif
2053}
2054
2055static void dynamic_debug_remove(struct _ddebug *debug)
2056{
2057    if (debug)
2058        ddebug_remove_module(debug->modname);
2059}
2060
2061static void *module_alloc_update_bounds(unsigned long size)
2062{
2063    void *ret = module_alloc(size);
2064
2065    if (ret) {
2066        mutex_lock(&module_mutex);
2067        /* Update module bounds. */
2068        if ((unsigned long)ret < module_addr_min)
2069            module_addr_min = (unsigned long)ret;
2070        if ((unsigned long)ret + size > module_addr_max)
2071            module_addr_max = (unsigned long)ret + size;
2072        mutex_unlock(&module_mutex);
2073    }
2074    return ret;
2075}
2076
2077#ifdef CONFIG_DEBUG_KMEMLEAK
2078static void kmemleak_load_module(const struct module *mod,
2079                 const struct load_info *info)
2080{
2081    unsigned int i;
2082
2083    /* only scan the sections containing data */
2084    kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2085
2086    for (i = 1; i < info->hdr->e_shnum; i++) {
2087        const char *name = info->secstrings + info->sechdrs[i].sh_name;
2088        if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2089            continue;
2090        if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2091            continue;
2092
2093        kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2094                   info->sechdrs[i].sh_size, GFP_KERNEL);
2095    }
2096}
2097#else
2098static inline void kmemleak_load_module(const struct module *mod,
2099                    const struct load_info *info)
2100{
2101}
2102#endif
2103
2104/* Sets info->hdr and info->len. */
2105static int copy_and_check(struct load_info *info,
2106              const void __user *umod, unsigned long len,
2107              const char __user *uargs)
2108{
2109    int err;
2110    Elf_Ehdr *hdr;
2111
2112    if (len < sizeof(*hdr))
2113        return -ENOEXEC;
2114
2115    /* Suck in entire file: we'll want most of it. */
2116    /* vmalloc barfs on "unusual" numbers. Check here */
2117    if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
2118        return -ENOMEM;
2119
2120    if (copy_from_user(hdr, umod, len) != 0) {
2121        err = -EFAULT;
2122        goto free_hdr;
2123    }
2124
2125    /* Sanity checks against insmoding binaries or wrong arch,
2126       weird elf version */
2127    if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2128        || hdr->e_type != ET_REL
2129        || !elf_check_arch(hdr)
2130        || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2131        err = -ENOEXEC;
2132        goto free_hdr;
2133    }
2134
2135    if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
2136        err = -ENOEXEC;
2137        goto free_hdr;
2138    }
2139
2140    info->hdr = hdr;
2141    info->len = len;
2142    return 0;
2143
2144free_hdr:
2145    vfree(hdr);
2146    return err;
2147}
2148
2149static void free_copy(struct load_info *info)
2150{
2151    vfree(info->hdr);
2152}
2153
2154static int rewrite_section_headers(struct load_info *info)
2155{
2156    unsigned int i;
2157
2158    /* This should always be true, but let's be sure. */
2159    info->sechdrs[0].sh_addr = 0;
2160
2161    for (i = 1; i < info->hdr->e_shnum; i++) {
2162        Elf_Shdr *shdr = &info->sechdrs[i];
2163        if (shdr->sh_type != SHT_NOBITS
2164            && info->len < shdr->sh_offset + shdr->sh_size) {
2165            printk(KERN_ERR "Module len %lu truncated\n",
2166                   info->len);
2167            return -ENOEXEC;
2168        }
2169
2170        /* Mark all sections sh_addr with their address in the
2171           temporary image. */
2172        shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2173
2174#ifndef CONFIG_MODULE_UNLOAD
2175        /* Don't load .exit sections */
2176        if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2177            shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2178#endif
2179    }
2180
2181    /* Track but don't keep modinfo and version sections. */
2182    info->index.vers = find_sec(info, "__versions");
2183    info->index.info = find_sec(info, ".modinfo");
2184    info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2185    info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2186    return 0;
2187}
2188
2189/*
2190 * Set up our basic convenience variables (pointers to section headers,
2191 * search for module section index etc), and do some basic section
2192 * verification.
2193 *
2194 * Return the temporary module pointer (we'll replace it with the final
2195 * one when we move the module sections around).
2196 */
2197static struct module *setup_load_info(struct load_info *info)
2198{
2199    unsigned int i;
2200    int err;
2201    struct module *mod;
2202
2203    /* Set up the convenience variables */
2204    info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2205    info->secstrings = (void *)info->hdr
2206        + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2207
2208    err = rewrite_section_headers(info);
2209    if (err)
2210        return ERR_PTR(err);
2211
2212    /* Find internal symbols and strings. */
2213    for (i = 1; i < info->hdr->e_shnum; i++) {
2214        if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2215            info->index.sym = i;
2216            info->index.str = info->sechdrs[i].sh_link;
2217            info->strtab = (char *)info->hdr
2218                + info->sechdrs[info->index.str].sh_offset;
2219            break;
2220        }
2221    }
2222
2223    info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2224    if (!info->index.mod) {
2225        printk(KERN_WARNING "No module found in object\n");
2226        return ERR_PTR(-ENOEXEC);
2227    }
2228    /* This is temporary: point mod into copy of data. */
2229    mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2230
2231    if (info->index.sym == 0) {
2232        printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2233               mod->name);
2234        return ERR_PTR(-ENOEXEC);
2235    }
2236
2237    info->index.pcpu = find_pcpusec(info);
2238
2239    /* Check module struct version now, before we try to use module. */
2240    if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2241        return ERR_PTR(-ENOEXEC);
2242
2243    return mod;
2244}
2245
2246static int check_modinfo(struct module *mod, struct load_info *info)
2247{
2248    const char *modmagic = get_modinfo(info, "vermagic");
2249    int err;
2250
2251    /* This is allowed: modprobe --force will invalidate it. */
2252    if (!modmagic) {
2253        err = try_to_force_load(mod, "bad vermagic");
2254        if (err)
2255            return err;
2256    } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2257        printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2258               mod->name, modmagic, vermagic);
2259        return -ENOEXEC;
2260    }
2261
2262    if (get_modinfo(info, "staging")) {
2263        add_taint_module(mod, TAINT_CRAP);
2264        printk(KERN_WARNING "%s: module is from the staging directory,"
2265               " the quality is unknown, you have been warned.\n",
2266               mod->name);
2267    }
2268
2269    /* Set up license info based on the info section */
2270    set_license(mod, get_modinfo(info, "license"));
2271
2272    return 0;
2273}
2274
2275static void find_module_sections(struct module *mod, struct load_info *info)
2276{
2277    mod->kp = section_objs(info, "__param",
2278                   sizeof(*mod->kp), &mod->num_kp);
2279    mod->syms = section_objs(info, "__ksymtab",
2280                 sizeof(*mod->syms), &mod->num_syms);
2281    mod->crcs = section_addr(info, "__kcrctab");
2282    mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2283                     sizeof(*mod->gpl_syms),
2284                     &mod->num_gpl_syms);
2285    mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2286    mod->gpl_future_syms = section_objs(info,
2287                        "__ksymtab_gpl_future",
2288                        sizeof(*mod->gpl_future_syms),
2289                        &mod->num_gpl_future_syms);
2290    mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2291
2292#ifdef CONFIG_UNUSED_SYMBOLS
2293    mod->unused_syms = section_objs(info, "__ksymtab_unused",
2294                    sizeof(*mod->unused_syms),
2295                    &mod->num_unused_syms);
2296    mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2297    mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2298                        sizeof(*mod->unused_gpl_syms),
2299                        &mod->num_unused_gpl_syms);
2300    mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2301#endif
2302#ifdef CONFIG_CONSTRUCTORS
2303    mod->ctors = section_objs(info, ".ctors",
2304                  sizeof(*mod->ctors), &mod->num_ctors);
2305#endif
2306
2307#ifdef CONFIG_TRACEPOINTS
2308    mod->tracepoints = section_objs(info, "__tracepoints",
2309                    sizeof(*mod->tracepoints),
2310                    &mod->num_tracepoints);
2311#endif
2312#ifdef CONFIG_EVENT_TRACING
2313    mod->trace_events = section_objs(info, "_ftrace_events",
2314                     sizeof(*mod->trace_events),
2315                     &mod->num_trace_events);
2316    /*
2317     * This section contains pointers to allocated objects in the trace
2318     * code and not scanning it leads to false positives.
2319     */
2320    kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2321               mod->num_trace_events, GFP_KERNEL);
2322#endif
2323#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2324    /* sechdrs[0].sh_size is always zero */
2325    mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2326                         sizeof(*mod->ftrace_callsites),
2327                         &mod->num_ftrace_callsites);
2328#endif
2329
2330    mod->extable = section_objs(info, "__ex_table",
2331                    sizeof(*mod->extable), &mod->num_exentries);
2332
2333    if (section_addr(info, "__obsparm"))
2334        printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2335               mod->name);
2336
2337    info->debug = section_objs(info, "__verbose",
2338                   sizeof(*info->debug), &info->num_debug);
2339}
2340
2341static int move_module(struct module *mod, struct load_info *info)
2342{
2343    int i;
2344    void *ptr;
2345
2346    /* Do the allocs. */
2347    ptr = module_alloc_update_bounds(mod->core_size);
2348    /*
2349     * The pointer to this block is stored in the module structure
2350     * which is inside the block. Just mark it as not being a
2351     * leak.
2352     */
2353    kmemleak_not_leak(ptr);
2354    if (!ptr)
2355        return -ENOMEM;
2356
2357    memset(ptr, 0, mod->core_size);
2358    mod->module_core = ptr;
2359
2360    ptr = module_alloc_update_bounds(mod->init_size);
2361    /*
2362     * The pointer to this block is stored in the module structure
2363     * which is inside the block. This block doesn't need to be
2364     * scanned as it contains data and code that will be freed
2365     * after the module is initialized.
2366     */
2367    kmemleak_ignore(ptr);
2368    if (!ptr && mod->init_size) {
2369        module_free(mod, mod->module_core);
2370        return -ENOMEM;
2371    }
2372    memset(ptr, 0, mod->init_size);
2373    mod->module_init = ptr;
2374
2375    /* Transfer each section which specifies SHF_ALLOC */
2376    DEBUGP("final section addresses:\n");
2377    for (i = 0; i < info->hdr->e_shnum; i++) {
2378        void *dest;
2379        Elf_Shdr *shdr = &info->sechdrs[i];
2380
2381        if (!(shdr->sh_flags & SHF_ALLOC))
2382            continue;
2383
2384        if (shdr->sh_entsize & INIT_OFFSET_MASK)
2385            dest = mod->module_init
2386                + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2387        else
2388            dest = mod->module_core + shdr->sh_entsize;
2389
2390        if (shdr->sh_type != SHT_NOBITS)
2391            memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2392        /* Update sh_addr to point to copy in image. */
2393        shdr->sh_addr = (unsigned long)dest;
2394        DEBUGP("\t0x%lx %s\n",
2395               shdr->sh_addr, info->secstrings + shdr->sh_name);
2396    }
2397
2398    return 0;
2399}
2400
2401static int check_module_license_and_versions(struct module *mod)
2402{
2403    /*
2404     * ndiswrapper is under GPL by itself, but loads proprietary modules.
2405     * Don't use add_taint_module(), as it would prevent ndiswrapper from
2406     * using GPL-only symbols it needs.
2407     */
2408    if (strcmp(mod->name, "ndiswrapper") == 0)
2409        add_taint(TAINT_PROPRIETARY_MODULE);
2410
2411    /* driverloader was caught wrongly pretending to be under GPL */
2412    if (strcmp(mod->name, "driverloader") == 0)
2413        add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2414
2415#ifdef CONFIG_MODVERSIONS
2416    if ((mod->num_syms && !mod->crcs)
2417        || (mod->num_gpl_syms && !mod->gpl_crcs)
2418        || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2419#ifdef CONFIG_UNUSED_SYMBOLS
2420        || (mod->num_unused_syms && !mod->unused_crcs)
2421        || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2422#endif
2423        ) {
2424        return try_to_force_load(mod,
2425                     "no versions for exported symbols");
2426    }
2427#endif
2428    return 0;
2429}
2430
2431static void flush_module_icache(const struct module *mod)
2432{
2433    mm_segment_t old_fs;
2434
2435    /* flush the icache in correct context */
2436    old_fs = get_fs();
2437    set_fs(KERNEL_DS);
2438
2439    /*
2440     * Flush the instruction cache, since we've played with text.
2441     * Do it before processing of module parameters, so the module
2442     * can provide parameter accessor functions of its own.
2443     */
2444    if (mod->module_init)
2445        flush_icache_range((unsigned long)mod->module_init,
2446                   (unsigned long)mod->module_init
2447                   + mod->init_size);
2448    flush_icache_range((unsigned long)mod->module_core,
2449               (unsigned long)mod->module_core + mod->core_size);
2450
2451    set_fs(old_fs);
2452}
2453
2454static struct module *layout_and_allocate(struct load_info *info)
2455{
2456    /* Module within temporary copy. */
2457    struct module *mod;
2458    Elf_Shdr *pcpusec;
2459    int err;
2460
2461    mod = setup_load_info(info);
2462    if (IS_ERR(mod))
2463        return mod;
2464
2465    err = check_modinfo(mod, info);
2466    if (err)
2467        return ERR_PTR(err);
2468
2469    /* Allow arches to frob section contents and sizes. */
2470    err = module_frob_arch_sections(info->hdr, info->sechdrs,
2471                    info->secstrings, mod);
2472    if (err < 0)
2473        goto out;
2474
2475    pcpusec = &info->sechdrs[info->index.pcpu];
2476    if (pcpusec->sh_size) {
2477        /* We have a special allocation for this section. */
2478        err = percpu_modalloc(mod,
2479                      pcpusec->sh_size, pcpusec->sh_addralign);
2480        if (err)
2481            goto out;
2482        pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2483    }
2484
2485    /* Determine total sizes, and put offsets in sh_entsize. For now
2486       this is done generically; there doesn't appear to be any
2487       special cases for the architectures. */
2488    layout_sections(mod, info);
2489
2490    info->strmap = kzalloc(BITS_TO_LONGS(info->sechdrs[info->index.str].sh_size)
2491             * sizeof(long), GFP_KERNEL);
2492    if (!info->strmap) {
2493        err = -ENOMEM;
2494        goto free_percpu;
2495    }
2496    layout_symtab(mod, info);
2497
2498    /* Allocate and move to the final place */
2499    err = move_module(mod, info);
2500    if (err)
2501        goto free_strmap;
2502
2503    /* Module has been copied to its final place now: return it. */
2504    mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2505    kmemleak_load_module(mod, info);
2506    return mod;
2507
2508free_strmap:
2509    kfree(info->strmap);
2510free_percpu:
2511    percpu_modfree(mod);
2512out:
2513    return ERR_PTR(err);
2514}
2515
2516/* mod is no longer valid after this! */
2517static void module_deallocate(struct module *mod, struct load_info *info)
2518{
2519    kfree(info->strmap);
2520    percpu_modfree(mod);
2521    module_free(mod, mod->module_init);
2522    module_free(mod, mod->module_core);
2523}
2524
2525static int post_relocation(struct module *mod, const struct load_info *info)
2526{
2527    /* Sort exception table now relocations are done. */
2528    sort_extable(mod->extable, mod->extable + mod->num_exentries);
2529
2530    /* Copy relocated percpu area over. */
2531    percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2532               info->sechdrs[info->index.pcpu].sh_size);
2533
2534    /* Setup kallsyms-specific fields. */
2535    add_kallsyms(mod, info);
2536
2537    /* Arch-specific module finalizing. */
2538    return module_finalize(info->hdr, info->sechdrs, mod);
2539}
2540
2541/* Allocate and load the module: note that size of section 0 is always
2542   zero, and we rely on this for optional sections. */
2543static struct module *load_module(void __user *umod,
2544                  unsigned long len,
2545                  const char __user *uargs)
2546{
2547    struct load_info info = { NULL, };
2548    struct module *mod;
2549    long err;
2550
2551    DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
2552           umod, len, uargs);
2553
2554    /* Copy in the blobs from userspace, check they are vaguely sane. */
2555    err = copy_and_check(&info, umod, len, uargs);
2556    if (err)
2557        return ERR_PTR(err);
2558
2559    /* Figure out module layout, and allocate all the memory. */
2560    mod = layout_and_allocate(&info);
2561    if (IS_ERR(mod)) {
2562        err = PTR_ERR(mod);
2563        goto free_copy;
2564    }
2565
2566    /* Now module is in final location, initialize linked lists, etc. */
2567    err = module_unload_init(mod);
2568    if (err)
2569        goto free_module;
2570
2571    /* Now we've got everything in the final locations, we can
2572     * find optional sections. */
2573    find_module_sections(mod, &info);
2574
2575    err = check_module_license_and_versions(mod);
2576    if (err)
2577        goto free_unload;
2578
2579    /* Set up MODINFO_ATTR fields */
2580    setup_modinfo(mod, &info);
2581
2582    /* Fix up syms, so that st_value is a pointer to location. */
2583    err = simplify_symbols(mod, &info);
2584    if (err < 0)
2585        goto free_modinfo;
2586
2587    err = apply_relocations(mod, &info);
2588    if (err < 0)
2589        goto free_modinfo;
2590
2591    err = post_relocation(mod, &info);
2592    if (err < 0)
2593        goto free_modinfo;
2594
2595    flush_module_icache(mod);
2596
2597    /* Now copy in args */
2598    mod->args = strndup_user(uargs, ~0UL >> 1);
2599    if (IS_ERR(mod->args)) {
2600        err = PTR_ERR(mod->args);
2601        goto free_arch_cleanup;
2602    }
2603
2604    /* Mark state as coming so strong_try_module_get() ignores us. */
2605    mod->state = MODULE_STATE_COMING;
2606
2607    /* Now sew it into the lists so we can get lockdep and oops
2608     * info during argument parsing. Noone should access us, since
2609     * strong_try_module_get() will fail.
2610     * lockdep/oops can run asynchronous, so use the RCU list insertion
2611     * function to insert in a way safe to concurrent readers.
2612     * The mutex protects against concurrent writers.
2613     */
2614    mutex_lock(&module_mutex);
2615    if (find_module(mod->name)) {
2616        err = -EEXIST;
2617        goto unlock;
2618    }
2619
2620    /* This has to be done once we're sure module name is unique. */
2621    if (!mod->taints)
2622        dynamic_debug_setup(info.debug, info.num_debug);
2623
2624    /* Find duplicate symbols */
2625    err = verify_export_symbols(mod);
2626    if (err < 0)
2627        goto ddebug;
2628
2629    module_bug_finalize(info.hdr, info.sechdrs, mod);
2630    list_add_rcu(&mod->list, &modules);
2631    mutex_unlock(&module_mutex);
2632
2633    /* Module is ready to execute: parsing args may do that. */
2634    err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
2635    if (err < 0)
2636        goto unlink;
2637
2638    /* Link in to syfs. */
2639    err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2640    if (err < 0)
2641        goto unlink;
2642
2643    /* Get rid of temporary copy and strmap. */
2644    kfree(info.strmap);
2645    free_copy(&info);
2646
2647    /* Done! */
2648    trace_module_load(mod);
2649    return mod;
2650
2651 unlink:
2652    mutex_lock(&module_mutex);
2653    /* Unlink carefully: kallsyms could be walking list. */
2654    list_del_rcu(&mod->list);
2655    module_bug_cleanup(mod);
2656
2657 ddebug:
2658    if (!mod->taints)
2659        dynamic_debug_remove(info.debug);
2660 unlock:
2661    mutex_unlock(&module_mutex);
2662    synchronize_sched();
2663    kfree(mod->args);
2664 free_arch_cleanup:
2665    module_arch_cleanup(mod);
2666 free_modinfo:
2667    free_modinfo(mod);
2668 free_unload:
2669    module_unload_free(mod);
2670 free_module:
2671    module_deallocate(mod, &info);
2672 free_copy:
2673    free_copy(&info);
2674    return ERR_PTR(err);
2675}
2676
2677/* Call module constructors. */
2678static void do_mod_ctors(struct module *mod)
2679{
2680#ifdef CONFIG_CONSTRUCTORS
2681    unsigned long i;
2682
2683    for (i = 0; i < mod->num_ctors; i++)
2684        mod->ctors[i]();
2685#endif
2686}
2687
2688/* This is where the real work happens */
2689SYSCALL_DEFINE3(init_module, void __user *, umod,
2690        unsigned long, len, const char __user *, uargs)
2691{
2692    struct module *mod;
2693    int ret = 0;
2694
2695    /* Must have permission */
2696    if (!capable(CAP_SYS_MODULE) || modules_disabled)
2697        return -EPERM;
2698
2699    /* Do all the hard work */
2700    mod = load_module(umod, len, uargs);
2701    if (IS_ERR(mod))
2702        return PTR_ERR(mod);
2703
2704    blocking_notifier_call_chain(&module_notify_list,
2705            MODULE_STATE_COMING, mod);
2706
2707    do_mod_ctors(mod);
2708    /* Start the module */
2709    if (mod->init != NULL)
2710        ret = do_one_initcall(mod->init);
2711    if (ret < 0) {
2712        /* Init routine failed: abort. Try to protect us from
2713                   buggy refcounters. */
2714        mod->state = MODULE_STATE_GOING;
2715        synchronize_sched();
2716        module_put(mod);
2717        blocking_notifier_call_chain(&module_notify_list,
2718                         MODULE_STATE_GOING, mod);
2719        free_module(mod);
2720        wake_up(&module_wq);
2721        return ret;
2722    }
2723    if (ret > 0) {
2724        printk(KERN_WARNING
2725"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
2726"%s: loading module anyway...\n",
2727               __func__, mod->name, ret,
2728               __func__);
2729        dump_stack();
2730    }
2731
2732    /* Now it's a first class citizen! Wake up anyone waiting for it. */
2733    mod->state = MODULE_STATE_LIVE;
2734    wake_up(&module_wq);
2735    blocking_notifier_call_chain(&module_notify_list,
2736                     MODULE_STATE_LIVE, mod);
2737
2738    /* We need to finish all async code before the module init sequence is done */
2739    async_synchronize_full();
2740
2741    mutex_lock(&module_mutex);
2742    /* Drop initial reference. */
2743    module_put(mod);
2744    trim_init_extable(mod);
2745#ifdef CONFIG_KALLSYMS
2746    mod->num_symtab = mod->core_num_syms;
2747    mod->symtab = mod->core_symtab;
2748    mod->strtab = mod->core_strtab;
2749#endif
2750    module_free(mod, mod->module_init);
2751    mod->module_init = NULL;
2752    mod->init_size = 0;
2753    mod->init_text_size = 0;
2754    mutex_unlock(&module_mutex);
2755
2756    return 0;
2757}
2758
2759static inline int within(unsigned long addr, void *start, unsigned long size)
2760{
2761    return ((void *)addr >= start && (void *)addr < start + size);
2762}
2763
2764#ifdef CONFIG_KALLSYMS
2765/*
2766 * This ignores the intensely annoying "mapping symbols" found
2767 * in ARM ELF files: $a, $t and $d.
2768 */
2769static inline int is_arm_mapping_symbol(const char *str)
2770{
2771    return str[0] == '$' && strchr("atd", str[1])
2772           && (str[2] == '\0' || str[2] == '.');
2773}
2774
2775static const char *get_ksymbol(struct module *mod,
2776                   unsigned long addr,
2777                   unsigned long *size,
2778                   unsigned long *offset)
2779{
2780    unsigned int i, best = 0;
2781    unsigned long nextval;
2782
2783    /* At worse, next value is at end of module */
2784    if (within_module_init(addr, mod))
2785        nextval = (unsigned long)mod->module_init+mod->init_text_size;
2786    else
2787        nextval = (unsigned long)mod->module_core+mod->core_text_size;
2788
2789    /* Scan for closest preceeding symbol, and next symbol. (ELF
2790       starts real symbols at 1). */
2791    for (i = 1; i < mod->num_symtab; i++) {
2792        if (mod->symtab[i].st_shndx == SHN_UNDEF)
2793            continue;
2794
2795        /* We ignore unnamed symbols: they're uninformative
2796         * and inserted at a whim. */
2797        if (mod->symtab[i].st_value <= addr
2798            && mod->symtab[i].st_value > mod->symtab[best].st_value
2799            && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2800            && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2801            best = i;
2802        if (mod->symtab[i].st_value > addr
2803            && mod->symtab[i].st_value < nextval
2804            && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2805            && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2806            nextval = mod->symtab[i].st_value;
2807    }
2808
2809    if (!best)
2810        return NULL;
2811
2812    if (size)
2813        *size = nextval - mod->symtab[best].st_value;
2814    if (offset)
2815        *offset = addr - mod->symtab[best].st_value;
2816    return mod->strtab + mod->symtab[best].st_name;
2817}
2818
2819/* For kallsyms to ask for address resolution. NULL means not found. Careful
2820 * not to lock to avoid deadlock on oopses, simply disable preemption. */
2821const char *module_address_lookup(unsigned long addr,
2822                unsigned long *size,
2823                unsigned long *offset,
2824                char **modname,
2825                char *namebuf)
2826{
2827    struct module *mod;
2828    const char *ret = NULL;
2829
2830    preempt_disable();
2831    list_for_each_entry_rcu(mod, &modules, list) {
2832        if (within_module_init(addr, mod) ||
2833            within_module_core(addr, mod)) {
2834            if (modname)
2835                *modname = mod->name;
2836            ret = get_ksymbol(mod, addr, size, offset);
2837            break;
2838        }
2839    }
2840    /* Make a copy in here where it's safe */
2841    if (ret) {
2842        strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
2843        ret = namebuf;
2844    }
2845    preempt_enable();
2846    return ret;
2847}
2848
2849int lookup_module_symbol_name(unsigned long addr, char *symname)
2850{
2851    struct module *mod;
2852
2853    preempt_disable();
2854    list_for_each_entry_rcu(mod, &modules, list) {
2855        if (within_module_init(addr, mod) ||
2856            within_module_core(addr, mod)) {
2857            const char *sym;
2858
2859            sym = get_ksymbol(mod, addr, NULL, NULL);
2860            if (!sym)
2861                goto out;
2862            strlcpy(symname, sym, KSYM_NAME_LEN);
2863            preempt_enable();
2864            return 0;
2865        }
2866    }
2867out:
2868    preempt_enable();
2869    return -ERANGE;
2870}
2871
2872int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
2873            unsigned long *offset, char *modname, char *name)
2874{
2875    struct module *mod;
2876
2877    preempt_disable();
2878    list_for_each_entry_rcu(mod, &modules, list) {
2879        if (within_module_init(addr, mod) ||
2880            within_module_core(addr, mod)) {
2881            const char *sym;
2882
2883            sym = get_ksymbol(mod, addr, size, offset);
2884            if (!sym)
2885                goto out;
2886            if (modname)
2887                strlcpy(modname, mod->name, MODULE_NAME_LEN);
2888            if (name)
2889                strlcpy(name, sym, KSYM_NAME_LEN);
2890            preempt_enable();
2891            return 0;
2892        }
2893    }
2894out:
2895    preempt_enable();
2896    return -ERANGE;
2897}
2898
2899int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
2900            char *name, char *module_name, int *exported)
2901{
2902    struct module *mod;
2903
2904    preempt_disable();
2905    list_for_each_entry_rcu(mod, &modules, list) {
2906        if (symnum < mod->num_symtab) {
2907            *value = mod->symtab[symnum].st_value;
2908            *type = mod->symtab[symnum].st_info;
2909            strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2910                KSYM_NAME_LEN);
2911            strlcpy(module_name, mod->name, MODULE_NAME_LEN);
2912            *exported = is_exported(name, *value, mod);
2913            preempt_enable();
2914            return 0;
2915        }
2916        symnum -= mod->num_symtab;
2917    }
2918    preempt_enable();
2919    return -ERANGE;
2920}
2921
2922static unsigned long mod_find_symname(struct module *mod, const char *name)
2923{
2924    unsigned int i;
2925
2926    for (i = 0; i < mod->num_symtab; i++)
2927        if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2928            mod->symtab[i].st_info != 'U')
2929            return mod->symtab[i].st_value;
2930    return 0;
2931}
2932
2933/* Look for this name: can be of form module:name. */
2934unsigned long module_kallsyms_lookup_name(const char *name)
2935{
2936    struct module *mod;
2937    char *colon;
2938    unsigned long ret = 0;
2939
2940    /* Don't lock: we're in enough trouble already. */
2941    preempt_disable();
2942    if ((colon = strchr(name, ':')) != NULL) {
2943        *colon = '\0';
2944        if ((mod = find_module(name)) != NULL)
2945            ret = mod_find_symname(mod, colon+1);
2946        *colon = ':';
2947    } else {
2948        list_for_each_entry_rcu(mod, &modules, list)
2949            if ((ret = mod_find_symname(mod, name)) != 0)
2950                break;
2951    }
2952    preempt_enable();
2953    return ret;
2954}
2955
2956int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
2957                         struct module *, unsigned long),
2958                   void *data)
2959{
2960    struct module *mod;
2961    unsigned int i;
2962    int ret;
2963
2964    list_for_each_entry(mod, &modules, list) {
2965        for (i = 0; i < mod->num_symtab; i++) {
2966            ret = fn(data, mod->strtab + mod->symtab[i].st_name,
2967                 mod, mod->symtab[i].st_value);
2968            if (ret != 0)
2969                return ret;
2970        }
2971    }
2972    return 0;
2973}
2974#endif /* CONFIG_KALLSYMS */
2975
2976static char *module_flags(struct module *mod, char *buf)
2977{
2978    int bx = 0;
2979
2980    if (mod->taints ||
2981        mod->state == MODULE_STATE_GOING ||
2982        mod->state == MODULE_STATE_COMING) {
2983        buf[bx++] = '(';
2984        if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
2985            buf[bx++] = 'P';
2986        if (mod->taints & (1 << TAINT_FORCED_MODULE))
2987            buf[bx++] = 'F';
2988        if (mod->taints & (1 << TAINT_CRAP))
2989            buf[bx++] = 'C';
2990        /*
2991         * TAINT_FORCED_RMMOD: could be added.
2992         * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2993         * apply to modules.
2994         */
2995
2996        /* Show a - for module-is-being-unloaded */
2997        if (mod->state == MODULE_STATE_GOING)
2998            buf[bx++] = '-';
2999        /* Show a + for module-is-being-loaded */
3000        if (mod->state == MODULE_STATE_COMING)
3001            buf[bx++] = '+';
3002        buf[bx++] = ')';
3003    }
3004    buf[bx] = '\0';
3005
3006    return buf;
3007}
3008
3009#ifdef CONFIG_PROC_FS
3010/* Called by the /proc file system to return a list of modules. */
3011static void *m_start(struct seq_file *m, loff_t *pos)
3012{
3013    mutex_lock(&module_mutex);
3014    return seq_list_start(&modules, *pos);
3015}
3016
3017static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3018{
3019    return seq_list_next(p, &modules, pos);
3020}
3021
3022static void m_stop(struct seq_file *m, void *p)
3023{
3024    mutex_unlock(&module_mutex);
3025}
3026
3027static int m_show(struct seq_file *m, void *p)
3028{
3029    struct module *mod = list_entry(p, struct module, list);
3030    char buf[8];
3031
3032    seq_printf(m, "%s %u",
3033           mod->name, mod->init_size + mod->core_size);
3034    print_unload_info(m, mod);
3035
3036    /* Informative for users. */
3037    seq_printf(m, " %s",
3038           mod->state == MODULE_STATE_GOING ? "Unloading":
3039           mod->state == MODULE_STATE_COMING ? "Loading":
3040           "Live");
3041    /* Used by oprofile and other similar tools. */
3042    seq_printf(m, " 0x%p", mod->module_core);
3043
3044    /* Taints info */
3045    if (mod->taints)
3046        seq_printf(m, " %s", module_flags(mod, buf));
3047
3048    seq_printf(m, "\n");
3049    return 0;
3050}
3051
3052/* Format: modulename size refcount deps address
3053
3054   Where refcount is a number or -, and deps is a comma-separated list
3055   of depends or -.
3056*/
3057static const struct seq_operations modules_op = {
3058    .start = m_start,
3059    .next = m_next,
3060    .stop = m_stop,
3061    .show = m_show
3062};
3063
3064static int modules_open(struct inode *inode, struct file *file)
3065{
3066    return seq_open(file, &modules_op);
3067}
3068
3069static const struct file_operations proc_modules_operations = {
3070    .open = modules_open,
3071    .read = seq_read,
3072    .llseek = seq_lseek,
3073    .release = seq_release,
3074};
3075
3076static int __init proc_modules_init(void)
3077{
3078    proc_create("modules", 0, NULL, &proc_modules_operations);
3079    return 0;
3080}
3081module_init(proc_modules_init);
3082#endif
3083
3084/* Given an address, look for it in the module exception tables. */
3085const struct exception_table_entry *search_module_extables(unsigned long addr)
3086{
3087    const struct exception_table_entry *e = NULL;
3088    struct module *mod;
3089
3090    preempt_disable();
3091    list_for_each_entry_rcu(mod, &modules, list) {
3092        if (mod->num_exentries == 0)
3093            continue;
3094
3095        e = search_extable(mod->extable,
3096                   mod->extable + mod->num_exentries - 1,
3097                   addr);
3098        if (e)
3099            break;
3100    }
3101    preempt_enable();
3102
3103    /* Now, if we found one, we are running inside it now, hence
3104       we cannot unload the module, hence no refcnt needed. */
3105    return e;
3106}
3107
3108/*
3109 * is_module_address - is this address inside a module?
3110 * @addr: the address to check.
3111 *
3112 * See is_module_text_address() if you simply want to see if the address
3113 * is code (not data).
3114 */
3115bool is_module_address(unsigned long addr)
3116{
3117    bool ret;
3118
3119    preempt_disable();
3120    ret = __module_address(addr) != NULL;
3121    preempt_enable();
3122
3123    return ret;
3124}
3125
3126/*
3127 * __module_address - get the module which contains an address.
3128 * @addr: the address.
3129 *
3130 * Must be called with preempt disabled or module mutex held so that
3131 * module doesn't get freed during this.
3132 */
3133struct module *__module_address(unsigned long addr)
3134{
3135    struct module *mod;
3136
3137    if (addr < module_addr_min || addr > module_addr_max)
3138        return NULL;
3139
3140    list_for_each_entry_rcu(mod, &modules, list)
3141        if (within_module_core(addr, mod)
3142            || within_module_init(addr, mod))
3143            return mod;
3144    return NULL;
3145}
3146EXPORT_SYMBOL_GPL(__module_address);
3147
3148/*
3149 * is_module_text_address - is this address inside module code?
3150 * @addr: the address to check.
3151 *
3152 * See is_module_address() if you simply want to see if the address is
3153 * anywhere in a module. See kernel_text_address() for testing if an
3154 * address corresponds to kernel or module code.
3155 */
3156bool is_module_text_address(unsigned long addr)
3157{
3158    bool ret;
3159
3160    preempt_disable();
3161    ret = __module_text_address(addr) != NULL;
3162    preempt_enable();
3163
3164    return ret;
3165}
3166
3167/*
3168 * __module_text_address - get the module whose code contains an address.
3169 * @addr: the address.
3170 *
3171 * Must be called with preempt disabled or module mutex held so that
3172 * module doesn't get freed during this.
3173 */
3174struct module *__module_text_address(unsigned long addr)
3175{
3176    struct module *mod = __module_address(addr);
3177    if (mod) {
3178        /* Make sure it's within the text section. */
3179        if (!within(addr, mod->module_init, mod->init_text_size)
3180            && !within(addr, mod->module_core, mod->core_text_size))
3181            mod = NULL;
3182    }
3183    return mod;
3184}
3185EXPORT_SYMBOL_GPL(__module_text_address);
3186
3187/* Don't grab lock, we're oopsing. */
3188void print_modules(void)
3189{
3190    struct module *mod;
3191    char buf[8];
3192
3193    printk(KERN_DEFAULT "Modules linked in:");
3194    /* Most callers should already have preempt disabled, but make sure */
3195    preempt_disable();
3196    list_for_each_entry_rcu(mod, &modules, list)
3197        printk(" %s%s", mod->name, module_flags(mod, buf));
3198    preempt_enable();
3199    if (last_unloaded_module[0])
3200        printk(" [last unloaded: %s]", last_unloaded_module);
3201    printk("\n");
3202}
3203
3204#ifdef CONFIG_MODVERSIONS
3205/* Generate the signature for all relevant module structures here.
3206 * If these change, we don't want to try to parse the module. */
3207void module_layout(struct module *mod,
3208           struct modversion_info *ver,
3209           struct kernel_param *kp,
3210           struct kernel_symbol *ks,
3211           struct tracepoint *tp)
3212{
3213}
3214EXPORT_SYMBOL(module_layout);
3215#endif
3216
3217#ifdef CONFIG_TRACEPOINTS
3218void module_update_tracepoints(void)
3219{
3220    struct module *mod;
3221
3222    mutex_lock(&module_mutex);
3223    list_for_each_entry(mod, &modules, list)
3224        if (!mod->taints)
3225            tracepoint_update_probe_range(mod->tracepoints,
3226                mod->tracepoints + mod->num_tracepoints);
3227    mutex_unlock(&module_mutex);
3228}
3229
3230/*
3231 * Returns 0 if current not found.
3232 * Returns 1 if current found.
3233 */
3234int module_get_iter_tracepoints(struct tracepoint_iter *iter)
3235{
3236    struct module *iter_mod;
3237    int found = 0;
3238
3239    mutex_lock(&module_mutex);
3240    list_for_each_entry(iter_mod, &modules, list) {
3241        if (!iter_mod->taints) {
3242            /*
3243             * Sorted module list
3244             */
3245            if (iter_mod < iter->module)
3246                continue;
3247            else if (iter_mod > iter->module)
3248                iter->tracepoint = NULL;
3249            found = tracepoint_get_iter_range(&iter->tracepoint,
3250                iter_mod->tracepoints,
3251                iter_mod->tracepoints
3252                    + iter_mod->num_tracepoints);
3253            if (found) {
3254                iter->module = iter_mod;
3255                break;
3256            }
3257        }
3258    }
3259    mutex_unlock(&module_mutex);
3260    return found;
3261}
3262#endif
3263

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