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/export.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#include <linux/jump_label.h>
59#include <linux/pfn.h>
60#include <linux/bsearch.h>
61
62#define CREATE_TRACE_POINTS
63#include <trace/events/module.h>
64
65#ifndef ARCH_SHF_SMALL
66#define ARCH_SHF_SMALL 0
67#endif
68
69/*
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
73 */
74#ifdef CONFIG_DEBUG_SET_MODULE_RONX
75# define debug_align(X) ALIGN(X, PAGE_SIZE)
76#else
77# define debug_align(X) (X)
78#endif
79
80/*
81 * Given BASE and SIZE this macro calculates the number of pages the
82 * memory regions occupies
83 */
84#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
85        (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
86             PFN_DOWN((unsigned long)BASE) + 1) \
87        : (0UL))
88
89/* If this is set, the section belongs in the init part of the module */
90#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
91
92/*
93 * Mutex protects:
94 * 1) List of modules (also safely readable with preempt_disable),
95 * 2) module_use links,
96 * 3) module_addr_min/module_addr_max.
97 * (delete uses stop_machine/add uses RCU list operations). */
98DEFINE_MUTEX(module_mutex);
99EXPORT_SYMBOL_GPL(module_mutex);
100static LIST_HEAD(modules);
101#ifdef CONFIG_KGDB_KDB
102struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
103#endif /* CONFIG_KGDB_KDB */
104
105
106/* Block module loading/unloading? */
107int modules_disabled = 0;
108core_param(nomodule, modules_disabled, bint, 0);
109
110/* Waiting for a module to finish initializing? */
111static DECLARE_WAIT_QUEUE_HEAD(module_wq);
112
113static BLOCKING_NOTIFIER_HEAD(module_notify_list);
114
115/* Bounds of module allocation, for speeding __module_address.
116 * Protected by module_mutex. */
117static unsigned long module_addr_min = -1UL, module_addr_max = 0;
118
119int register_module_notifier(struct notifier_block * nb)
120{
121    return blocking_notifier_chain_register(&module_notify_list, nb);
122}
123EXPORT_SYMBOL(register_module_notifier);
124
125int unregister_module_notifier(struct notifier_block * nb)
126{
127    return blocking_notifier_chain_unregister(&module_notify_list, nb);
128}
129EXPORT_SYMBOL(unregister_module_notifier);
130
131struct load_info {
132    Elf_Ehdr *hdr;
133    unsigned long len;
134    Elf_Shdr *sechdrs;
135    char *secstrings, *strtab;
136    unsigned long symoffs, stroffs;
137    struct _ddebug *debug;
138    unsigned int num_debug;
139    struct {
140        unsigned int sym, str, mod, vers, info, pcpu;
141    } index;
142};
143
144/* We require a truly strong try_module_get(): 0 means failure due to
145   ongoing or failed initialization etc. */
146static inline int strong_try_module_get(struct module *mod)
147{
148    if (mod && mod->state == MODULE_STATE_COMING)
149        return -EBUSY;
150    if (try_module_get(mod))
151        return 0;
152    else
153        return -ENOENT;
154}
155
156static inline void add_taint_module(struct module *mod, unsigned flag)
157{
158    add_taint(flag);
159    mod->taints |= (1U << flag);
160}
161
162/*
163 * A thread that wants to hold a reference to a module only while it
164 * is running can call this to safely exit. nfsd and lockd use this.
165 */
166void __module_put_and_exit(struct module *mod, long code)
167{
168    module_put(mod);
169    do_exit(code);
170}
171EXPORT_SYMBOL(__module_put_and_exit);
172
173/* Find a module section: 0 means not found. */
174static unsigned int find_sec(const struct load_info *info, const char *name)
175{
176    unsigned int i;
177
178    for (i = 1; i < info->hdr->e_shnum; i++) {
179        Elf_Shdr *shdr = &info->sechdrs[i];
180        /* Alloc bit cleared means "ignore it." */
181        if ((shdr->sh_flags & SHF_ALLOC)
182            && strcmp(info->secstrings + shdr->sh_name, name) == 0)
183            return i;
184    }
185    return 0;
186}
187
188/* Find a module section, or NULL. */
189static void *section_addr(const struct load_info *info, const char *name)
190{
191    /* Section 0 has sh_addr 0. */
192    return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
193}
194
195/* Find a module section, or NULL. Fill in number of "objects" in section. */
196static void *section_objs(const struct load_info *info,
197              const char *name,
198              size_t object_size,
199              unsigned int *num)
200{
201    unsigned int sec = find_sec(info, name);
202
203    /* Section 0 has sh_addr 0 and sh_size 0. */
204    *num = info->sechdrs[sec].sh_size / object_size;
205    return (void *)info->sechdrs[sec].sh_addr;
206}
207
208/* Provided by the linker */
209extern const struct kernel_symbol __start___ksymtab[];
210extern const struct kernel_symbol __stop___ksymtab[];
211extern const struct kernel_symbol __start___ksymtab_gpl[];
212extern const struct kernel_symbol __stop___ksymtab_gpl[];
213extern const struct kernel_symbol __start___ksymtab_gpl_future[];
214extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
215extern const unsigned long __start___kcrctab[];
216extern const unsigned long __start___kcrctab_gpl[];
217extern const unsigned long __start___kcrctab_gpl_future[];
218#ifdef CONFIG_UNUSED_SYMBOLS
219extern const struct kernel_symbol __start___ksymtab_unused[];
220extern const struct kernel_symbol __stop___ksymtab_unused[];
221extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
222extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
223extern const unsigned long __start___kcrctab_unused[];
224extern const unsigned long __start___kcrctab_unused_gpl[];
225#endif
226
227#ifndef CONFIG_MODVERSIONS
228#define symversion(base, idx) NULL
229#else
230#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
231#endif
232
233static bool each_symbol_in_section(const struct symsearch *arr,
234                   unsigned int arrsize,
235                   struct module *owner,
236                   bool (*fn)(const struct symsearch *syms,
237                          struct module *owner,
238                          void *data),
239                   void *data)
240{
241    unsigned int j;
242
243    for (j = 0; j < arrsize; j++) {
244        if (fn(&arr[j], owner, data))
245            return true;
246    }
247
248    return false;
249}
250
251/* Returns true as soon as fn returns true, otherwise false. */
252bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
253                    struct module *owner,
254                    void *data),
255             void *data)
256{
257    struct module *mod;
258    static const struct symsearch arr[] = {
259        { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
260          NOT_GPL_ONLY, false },
261        { __start___ksymtab_gpl, __stop___ksymtab_gpl,
262          __start___kcrctab_gpl,
263          GPL_ONLY, false },
264        { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
265          __start___kcrctab_gpl_future,
266          WILL_BE_GPL_ONLY, false },
267#ifdef CONFIG_UNUSED_SYMBOLS
268        { __start___ksymtab_unused, __stop___ksymtab_unused,
269          __start___kcrctab_unused,
270          NOT_GPL_ONLY, true },
271        { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
272          __start___kcrctab_unused_gpl,
273          GPL_ONLY, true },
274#endif
275    };
276
277    if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
278        return true;
279
280    list_for_each_entry_rcu(mod, &modules, list) {
281        struct symsearch arr[] = {
282            { mod->syms, mod->syms + mod->num_syms, mod->crcs,
283              NOT_GPL_ONLY, false },
284            { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
285              mod->gpl_crcs,
286              GPL_ONLY, false },
287            { mod->gpl_future_syms,
288              mod->gpl_future_syms + mod->num_gpl_future_syms,
289              mod->gpl_future_crcs,
290              WILL_BE_GPL_ONLY, false },
291#ifdef CONFIG_UNUSED_SYMBOLS
292            { mod->unused_syms,
293              mod->unused_syms + mod->num_unused_syms,
294              mod->unused_crcs,
295              NOT_GPL_ONLY, true },
296            { mod->unused_gpl_syms,
297              mod->unused_gpl_syms + mod->num_unused_gpl_syms,
298              mod->unused_gpl_crcs,
299              GPL_ONLY, true },
300#endif
301        };
302
303        if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
304            return true;
305    }
306    return false;
307}
308EXPORT_SYMBOL_GPL(each_symbol_section);
309
310struct find_symbol_arg {
311    /* Input */
312    const char *name;
313    bool gplok;
314    bool warn;
315
316    /* Output */
317    struct module *owner;
318    const unsigned long *crc;
319    const struct kernel_symbol *sym;
320};
321
322static bool check_symbol(const struct symsearch *syms,
323                 struct module *owner,
324                 unsigned int symnum, void *data)
325{
326    struct find_symbol_arg *fsa = data;
327
328    if (!fsa->gplok) {
329        if (syms->licence == GPL_ONLY)
330            return false;
331        if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
332            printk(KERN_WARNING "Symbol %s is being used "
333                   "by a non-GPL module, which will not "
334                   "be allowed in the future\n", fsa->name);
335            printk(KERN_WARNING "Please see the file "
336                   "Documentation/feature-removal-schedule.txt "
337                   "in the kernel source tree for more details.\n");
338        }
339    }
340
341#ifdef CONFIG_UNUSED_SYMBOLS
342    if (syms->unused && fsa->warn) {
343        printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
344               "however this module is using it.\n", fsa->name);
345        printk(KERN_WARNING
346               "This symbol will go away in the future.\n");
347        printk(KERN_WARNING
348               "Please evalute if this is the right api to use and if "
349               "it really is, submit a report the linux kernel "
350               "mailinglist together with submitting your code for "
351               "inclusion.\n");
352    }
353#endif
354
355    fsa->owner = owner;
356    fsa->crc = symversion(syms->crcs, symnum);
357    fsa->sym = &syms->start[symnum];
358    return true;
359}
360
361static int cmp_name(const void *va, const void *vb)
362{
363    const char *a;
364    const struct kernel_symbol *b;
365    a = va; b = vb;
366    return strcmp(a, b->name);
367}
368
369static bool find_symbol_in_section(const struct symsearch *syms,
370                   struct module *owner,
371                   void *data)
372{
373    struct find_symbol_arg *fsa = data;
374    struct kernel_symbol *sym;
375
376    sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
377            sizeof(struct kernel_symbol), cmp_name);
378
379    if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
380        return true;
381
382    return false;
383}
384
385/* Find a symbol and return it, along with, (optional) crc and
386 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
387const struct kernel_symbol *find_symbol(const char *name,
388                    struct module **owner,
389                    const unsigned long **crc,
390                    bool gplok,
391                    bool warn)
392{
393    struct find_symbol_arg fsa;
394
395    fsa.name = name;
396    fsa.gplok = gplok;
397    fsa.warn = warn;
398
399    if (each_symbol_section(find_symbol_in_section, &fsa)) {
400        if (owner)
401            *owner = fsa.owner;
402        if (crc)
403            *crc = fsa.crc;
404        return fsa.sym;
405    }
406
407    pr_debug("Failed to find symbol %s\n", name);
408    return NULL;
409}
410EXPORT_SYMBOL_GPL(find_symbol);
411
412/* Search for module by name: must hold module_mutex. */
413struct module *find_module(const char *name)
414{
415    struct module *mod;
416
417    list_for_each_entry(mod, &modules, list) {
418        if (strcmp(mod->name, name) == 0)
419            return mod;
420    }
421    return NULL;
422}
423EXPORT_SYMBOL_GPL(find_module);
424
425#ifdef CONFIG_SMP
426
427static inline void __percpu *mod_percpu(struct module *mod)
428{
429    return mod->percpu;
430}
431
432static int percpu_modalloc(struct module *mod,
433               unsigned long size, unsigned long align)
434{
435    if (align > PAGE_SIZE) {
436        printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
437               mod->name, align, PAGE_SIZE);
438        align = PAGE_SIZE;
439    }
440
441    mod->percpu = __alloc_reserved_percpu(size, align);
442    if (!mod->percpu) {
443        printk(KERN_WARNING
444               "%s: Could not allocate %lu bytes percpu data\n",
445               mod->name, size);
446        return -ENOMEM;
447    }
448    mod->percpu_size = size;
449    return 0;
450}
451
452static void percpu_modfree(struct module *mod)
453{
454    free_percpu(mod->percpu);
455}
456
457static unsigned int find_pcpusec(struct load_info *info)
458{
459    return find_sec(info, ".data..percpu");
460}
461
462static void percpu_modcopy(struct module *mod,
463               const void *from, unsigned long size)
464{
465    int cpu;
466
467    for_each_possible_cpu(cpu)
468        memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
469}
470
471/**
472 * is_module_percpu_address - test whether address is from module static percpu
473 * @addr: address to test
474 *
475 * Test whether @addr belongs to module static percpu area.
476 *
477 * RETURNS:
478 * %true if @addr is from module static percpu area
479 */
480bool is_module_percpu_address(unsigned long addr)
481{
482    struct module *mod;
483    unsigned int cpu;
484
485    preempt_disable();
486
487    list_for_each_entry_rcu(mod, &modules, list) {
488        if (!mod->percpu_size)
489            continue;
490        for_each_possible_cpu(cpu) {
491            void *start = per_cpu_ptr(mod->percpu, cpu);
492
493            if ((void *)addr >= start &&
494                (void *)addr < start + mod->percpu_size) {
495                preempt_enable();
496                return true;
497            }
498        }
499    }
500
501    preempt_enable();
502    return false;
503}
504
505#else /* ... !CONFIG_SMP */
506
507static inline void __percpu *mod_percpu(struct module *mod)
508{
509    return NULL;
510}
511static inline int percpu_modalloc(struct module *mod,
512                  unsigned long size, unsigned long align)
513{
514    return -ENOMEM;
515}
516static inline void percpu_modfree(struct module *mod)
517{
518}
519static unsigned int find_pcpusec(struct load_info *info)
520{
521    return 0;
522}
523static inline void percpu_modcopy(struct module *mod,
524                  const void *from, unsigned long size)
525{
526    /* pcpusec should be 0, and size of that section should be 0. */
527    BUG_ON(size != 0);
528}
529bool is_module_percpu_address(unsigned long addr)
530{
531    return false;
532}
533
534#endif /* CONFIG_SMP */
535
536#define MODINFO_ATTR(field) \
537static void setup_modinfo_##field(struct module *mod, const char *s) \
538{ \
539    mod->field = kstrdup(s, GFP_KERNEL); \
540} \
541static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
542            struct module_kobject *mk, char *buffer) \
543{ \
544    return sprintf(buffer, "%s\n", mk->mod->field); \
545} \
546static int modinfo_##field##_exists(struct module *mod) \
547{ \
548    return mod->field != NULL; \
549} \
550static void free_modinfo_##field(struct module *mod) \
551{ \
552    kfree(mod->field); \
553    mod->field = NULL; \
554} \
555static struct module_attribute modinfo_##field = { \
556    .attr = { .name = __stringify(field), .mode = 0444 }, \
557    .show = show_modinfo_##field, \
558    .setup = setup_modinfo_##field, \
559    .test = modinfo_##field##_exists, \
560    .free = free_modinfo_##field, \
561};
562
563MODINFO_ATTR(version);
564MODINFO_ATTR(srcversion);
565
566static char last_unloaded_module[MODULE_NAME_LEN+1];
567
568#ifdef CONFIG_MODULE_UNLOAD
569
570EXPORT_TRACEPOINT_SYMBOL(module_get);
571
572/* Init the unload section of the module. */
573static int module_unload_init(struct module *mod)
574{
575    mod->refptr = alloc_percpu(struct module_ref);
576    if (!mod->refptr)
577        return -ENOMEM;
578
579    INIT_LIST_HEAD(&mod->source_list);
580    INIT_LIST_HEAD(&mod->target_list);
581
582    /* Hold reference count during initialization. */
583    __this_cpu_write(mod->refptr->incs, 1);
584    /* Backwards compatibility macros put refcount during init. */
585    mod->waiter = current;
586
587    return 0;
588}
589
590/* Does a already use b? */
591static int already_uses(struct module *a, struct module *b)
592{
593    struct module_use *use;
594
595    list_for_each_entry(use, &b->source_list, source_list) {
596        if (use->source == a) {
597            pr_debug("%s uses %s!\n", a->name, b->name);
598            return 1;
599        }
600    }
601    pr_debug("%s does not use %s!\n", a->name, b->name);
602    return 0;
603}
604
605/*
606 * Module a uses b
607 * - we add 'a' as a "source", 'b' as a "target" of module use
608 * - the module_use is added to the list of 'b' sources (so
609 * 'b' can walk the list to see who sourced them), and of 'a'
610 * targets (so 'a' can see what modules it targets).
611 */
612static int add_module_usage(struct module *a, struct module *b)
613{
614    struct module_use *use;
615
616    pr_debug("Allocating new usage for %s.\n", a->name);
617    use = kmalloc(sizeof(*use), GFP_ATOMIC);
618    if (!use) {
619        printk(KERN_WARNING "%s: out of memory loading\n", a->name);
620        return -ENOMEM;
621    }
622
623    use->source = a;
624    use->target = b;
625    list_add(&use->source_list, &b->source_list);
626    list_add(&use->target_list, &a->target_list);
627    return 0;
628}
629
630/* Module a uses b: caller needs module_mutex() */
631int ref_module(struct module *a, struct module *b)
632{
633    int err;
634
635    if (b == NULL || already_uses(a, b))
636        return 0;
637
638    /* If module isn't available, we fail. */
639    err = strong_try_module_get(b);
640    if (err)
641        return err;
642
643    err = add_module_usage(a, b);
644    if (err) {
645        module_put(b);
646        return err;
647    }
648    return 0;
649}
650EXPORT_SYMBOL_GPL(ref_module);
651
652/* Clear the unload stuff of the module. */
653static void module_unload_free(struct module *mod)
654{
655    struct module_use *use, *tmp;
656
657    mutex_lock(&module_mutex);
658    list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
659        struct module *i = use->target;
660        pr_debug("%s unusing %s\n", mod->name, i->name);
661        module_put(i);
662        list_del(&use->source_list);
663        list_del(&use->target_list);
664        kfree(use);
665    }
666    mutex_unlock(&module_mutex);
667
668    free_percpu(mod->refptr);
669}
670
671#ifdef CONFIG_MODULE_FORCE_UNLOAD
672static inline int try_force_unload(unsigned int flags)
673{
674    int ret = (flags & O_TRUNC);
675    if (ret)
676        add_taint(TAINT_FORCED_RMMOD);
677    return ret;
678}
679#else
680static inline int try_force_unload(unsigned int flags)
681{
682    return 0;
683}
684#endif /* CONFIG_MODULE_FORCE_UNLOAD */
685
686struct stopref
687{
688    struct module *mod;
689    int flags;
690    int *forced;
691};
692
693/* Whole machine is stopped with interrupts off when this runs. */
694static int __try_stop_module(void *_sref)
695{
696    struct stopref *sref = _sref;
697
698    /* If it's not unused, quit unless we're forcing. */
699    if (module_refcount(sref->mod) != 0) {
700        if (!(*sref->forced = try_force_unload(sref->flags)))
701            return -EWOULDBLOCK;
702    }
703
704    /* Mark it as dying. */
705    sref->mod->state = MODULE_STATE_GOING;
706    return 0;
707}
708
709static int try_stop_module(struct module *mod, int flags, int *forced)
710{
711    if (flags & O_NONBLOCK) {
712        struct stopref sref = { mod, flags, forced };
713
714        return stop_machine(__try_stop_module, &sref, NULL);
715    } else {
716        /* We don't need to stop the machine for this. */
717        mod->state = MODULE_STATE_GOING;
718        synchronize_sched();
719        return 0;
720    }
721}
722
723unsigned long module_refcount(struct module *mod)
724{
725    unsigned long incs = 0, decs = 0;
726    int cpu;
727
728    for_each_possible_cpu(cpu)
729        decs += per_cpu_ptr(mod->refptr, cpu)->decs;
730    /*
731     * ensure the incs are added up after the decs.
732     * module_put ensures incs are visible before decs with smp_wmb.
733     *
734     * This 2-count scheme avoids the situation where the refcount
735     * for CPU0 is read, then CPU0 increments the module refcount,
736     * then CPU1 drops that refcount, then the refcount for CPU1 is
737     * read. We would record a decrement but not its corresponding
738     * increment so we would see a low count (disaster).
739     *
740     * Rare situation? But module_refcount can be preempted, and we
741     * might be tallying up 4096+ CPUs. So it is not impossible.
742     */
743    smp_rmb();
744    for_each_possible_cpu(cpu)
745        incs += per_cpu_ptr(mod->refptr, cpu)->incs;
746    return incs - decs;
747}
748EXPORT_SYMBOL(module_refcount);
749
750/* This exists whether we can unload or not */
751static void free_module(struct module *mod);
752
753static void wait_for_zero_refcount(struct module *mod)
754{
755    /* Since we might sleep for some time, release the mutex first */
756    mutex_unlock(&module_mutex);
757    for (;;) {
758        pr_debug("Looking at refcount...\n");
759        set_current_state(TASK_UNINTERRUPTIBLE);
760        if (module_refcount(mod) == 0)
761            break;
762        schedule();
763    }
764    current->state = TASK_RUNNING;
765    mutex_lock(&module_mutex);
766}
767
768SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
769        unsigned int, flags)
770{
771    struct module *mod;
772    char name[MODULE_NAME_LEN];
773    int ret, forced = 0;
774
775    if (!capable(CAP_SYS_MODULE) || modules_disabled)
776        return -EPERM;
777
778    if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
779        return -EFAULT;
780    name[MODULE_NAME_LEN-1] = '\0';
781
782    if (mutex_lock_interruptible(&module_mutex) != 0)
783        return -EINTR;
784
785    mod = find_module(name);
786    if (!mod) {
787        ret = -ENOENT;
788        goto out;
789    }
790
791    if (!list_empty(&mod->source_list)) {
792        /* Other modules depend on us: get rid of them first. */
793        ret = -EWOULDBLOCK;
794        goto out;
795    }
796
797    /* Doing init or already dying? */
798    if (mod->state != MODULE_STATE_LIVE) {
799        /* FIXME: if (force), slam module count and wake up
800                   waiter --RR */
801        pr_debug("%s already dying\n", mod->name);
802        ret = -EBUSY;
803        goto out;
804    }
805
806    /* If it has an init func, it must have an exit func to unload */
807    if (mod->init && !mod->exit) {
808        forced = try_force_unload(flags);
809        if (!forced) {
810            /* This module can't be removed */
811            ret = -EBUSY;
812            goto out;
813        }
814    }
815
816    /* Set this up before setting mod->state */
817    mod->waiter = current;
818
819    /* Stop the machine so refcounts can't move and disable module. */
820    ret = try_stop_module(mod, flags, &forced);
821    if (ret != 0)
822        goto out;
823
824    /* Never wait if forced. */
825    if (!forced && module_refcount(mod) != 0)
826        wait_for_zero_refcount(mod);
827
828    mutex_unlock(&module_mutex);
829    /* Final destruction now no one is using it. */
830    if (mod->exit != NULL)
831        mod->exit();
832    blocking_notifier_call_chain(&module_notify_list,
833                     MODULE_STATE_GOING, mod);
834    async_synchronize_full();
835
836    /* Store the name of the last unloaded module for diagnostic purposes */
837    strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
838
839    free_module(mod);
840    return 0;
841out:
842    mutex_unlock(&module_mutex);
843    return ret;
844}
845
846static inline void print_unload_info(struct seq_file *m, struct module *mod)
847{
848    struct module_use *use;
849    int printed_something = 0;
850
851    seq_printf(m, " %lu ", module_refcount(mod));
852
853    /* Always include a trailing , so userspace can differentiate
854           between this and the old multi-field proc format. */
855    list_for_each_entry(use, &mod->source_list, source_list) {
856        printed_something = 1;
857        seq_printf(m, "%s,", use->source->name);
858    }
859
860    if (mod->init != NULL && mod->exit == NULL) {
861        printed_something = 1;
862        seq_printf(m, "[permanent],");
863    }
864
865    if (!printed_something)
866        seq_printf(m, "-");
867}
868
869void __symbol_put(const char *symbol)
870{
871    struct module *owner;
872
873    preempt_disable();
874    if (!find_symbol(symbol, &owner, NULL, true, false))
875        BUG();
876    module_put(owner);
877    preempt_enable();
878}
879EXPORT_SYMBOL(__symbol_put);
880
881/* Note this assumes addr is a function, which it currently always is. */
882void symbol_put_addr(void *addr)
883{
884    struct module *modaddr;
885    unsigned long a = (unsigned long)dereference_function_descriptor(addr);
886
887    if (core_kernel_text(a))
888        return;
889
890    /* module_text_address is safe here: we're supposed to have reference
891     * to module from symbol_get, so it can't go away. */
892    modaddr = __module_text_address(a);
893    BUG_ON(!modaddr);
894    module_put(modaddr);
895}
896EXPORT_SYMBOL_GPL(symbol_put_addr);
897
898static ssize_t show_refcnt(struct module_attribute *mattr,
899               struct module_kobject *mk, char *buffer)
900{
901    return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
902}
903
904static struct module_attribute modinfo_refcnt =
905    __ATTR(refcnt, 0444, show_refcnt, NULL);
906
907void __module_get(struct module *module)
908{
909    if (module) {
910        preempt_disable();
911        __this_cpu_inc(module->refptr->incs);
912        trace_module_get(module, _RET_IP_);
913        preempt_enable();
914    }
915}
916EXPORT_SYMBOL(__module_get);
917
918bool try_module_get(struct module *module)
919{
920    bool ret = true;
921
922    if (module) {
923        preempt_disable();
924
925        if (likely(module_is_live(module))) {
926            __this_cpu_inc(module->refptr->incs);
927            trace_module_get(module, _RET_IP_);
928        } else
929            ret = false;
930
931        preempt_enable();
932    }
933    return ret;
934}
935EXPORT_SYMBOL(try_module_get);
936
937void module_put(struct module *module)
938{
939    if (module) {
940        preempt_disable();
941        smp_wmb(); /* see comment in module_refcount */
942        __this_cpu_inc(module->refptr->decs);
943
944        trace_module_put(module, _RET_IP_);
945        /* Maybe they're waiting for us to drop reference? */
946        if (unlikely(!module_is_live(module)))
947            wake_up_process(module->waiter);
948        preempt_enable();
949    }
950}
951EXPORT_SYMBOL(module_put);
952
953#else /* !CONFIG_MODULE_UNLOAD */
954static inline void print_unload_info(struct seq_file *m, struct module *mod)
955{
956    /* We don't know the usage count, or what modules are using. */
957    seq_printf(m, " - -");
958}
959
960static inline void module_unload_free(struct module *mod)
961{
962}
963
964int ref_module(struct module *a, struct module *b)
965{
966    return strong_try_module_get(b);
967}
968EXPORT_SYMBOL_GPL(ref_module);
969
970static inline int module_unload_init(struct module *mod)
971{
972    return 0;
973}
974#endif /* CONFIG_MODULE_UNLOAD */
975
976static size_t module_flags_taint(struct module *mod, char *buf)
977{
978    size_t l = 0;
979
980    if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
981        buf[l++] = 'P';
982    if (mod->taints & (1 << TAINT_OOT_MODULE))
983        buf[l++] = 'O';
984    if (mod->taints & (1 << TAINT_FORCED_MODULE))
985        buf[l++] = 'F';
986    if (mod->taints & (1 << TAINT_CRAP))
987        buf[l++] = 'C';
988    /*
989     * TAINT_FORCED_RMMOD: could be added.
990     * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
991     * apply to modules.
992     */
993    return l;
994}
995
996static ssize_t show_initstate(struct module_attribute *mattr,
997                  struct module_kobject *mk, char *buffer)
998{
999    const char *state = "unknown";
1000
1001    switch (mk->mod->state) {
1002    case MODULE_STATE_LIVE:
1003        state = "live";
1004        break;
1005    case MODULE_STATE_COMING:
1006        state = "coming";
1007        break;
1008    case MODULE_STATE_GOING:
1009        state = "going";
1010        break;
1011    }
1012    return sprintf(buffer, "%s\n", state);
1013}
1014
1015static struct module_attribute modinfo_initstate =
1016    __ATTR(initstate, 0444, show_initstate, NULL);
1017
1018static ssize_t store_uevent(struct module_attribute *mattr,
1019                struct module_kobject *mk,
1020                const char *buffer, size_t count)
1021{
1022    enum kobject_action action;
1023
1024    if (kobject_action_type(buffer, count, &action) == 0)
1025        kobject_uevent(&mk->kobj, action);
1026    return count;
1027}
1028
1029struct module_attribute module_uevent =
1030    __ATTR(uevent, 0200, NULL, store_uevent);
1031
1032static ssize_t show_coresize(struct module_attribute *mattr,
1033                 struct module_kobject *mk, char *buffer)
1034{
1035    return sprintf(buffer, "%u\n", mk->mod->core_size);
1036}
1037
1038static struct module_attribute modinfo_coresize =
1039    __ATTR(coresize, 0444, show_coresize, NULL);
1040
1041static ssize_t show_initsize(struct module_attribute *mattr,
1042                 struct module_kobject *mk, char *buffer)
1043{
1044    return sprintf(buffer, "%u\n", mk->mod->init_size);
1045}
1046
1047static struct module_attribute modinfo_initsize =
1048    __ATTR(initsize, 0444, show_initsize, NULL);
1049
1050static ssize_t show_taint(struct module_attribute *mattr,
1051              struct module_kobject *mk, char *buffer)
1052{
1053    size_t l;
1054
1055    l = module_flags_taint(mk->mod, buffer);
1056    buffer[l++] = '\n';
1057    return l;
1058}
1059
1060static struct module_attribute modinfo_taint =
1061    __ATTR(taint, 0444, show_taint, NULL);
1062
1063static struct module_attribute *modinfo_attrs[] = {
1064    &module_uevent,
1065    &modinfo_version,
1066    &modinfo_srcversion,
1067    &modinfo_initstate,
1068    &modinfo_coresize,
1069    &modinfo_initsize,
1070    &modinfo_taint,
1071#ifdef CONFIG_MODULE_UNLOAD
1072    &modinfo_refcnt,
1073#endif
1074    NULL,
1075};
1076
1077static const char vermagic[] = VERMAGIC_STRING;
1078
1079static int try_to_force_load(struct module *mod, const char *reason)
1080{
1081#ifdef CONFIG_MODULE_FORCE_LOAD
1082    if (!test_taint(TAINT_FORCED_MODULE))
1083        printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1084               mod->name, reason);
1085    add_taint_module(mod, TAINT_FORCED_MODULE);
1086    return 0;
1087#else
1088    return -ENOEXEC;
1089#endif
1090}
1091
1092#ifdef CONFIG_MODVERSIONS
1093/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1094static unsigned long maybe_relocated(unsigned long crc,
1095                     const struct module *crc_owner)
1096{
1097#ifdef ARCH_RELOCATES_KCRCTAB
1098    if (crc_owner == NULL)
1099        return crc - (unsigned long)reloc_start;
1100#endif
1101    return crc;
1102}
1103
1104static int check_version(Elf_Shdr *sechdrs,
1105             unsigned int versindex,
1106             const char *symname,
1107             struct module *mod,
1108             const unsigned long *crc,
1109             const struct module *crc_owner)
1110{
1111    unsigned int i, num_versions;
1112    struct modversion_info *versions;
1113
1114    /* Exporting module didn't supply crcs? OK, we're already tainted. */
1115    if (!crc)
1116        return 1;
1117
1118    /* No versions at all? modprobe --force does this. */
1119    if (versindex == 0)
1120        return try_to_force_load(mod, symname) == 0;
1121
1122    versions = (void *) sechdrs[versindex].sh_addr;
1123    num_versions = sechdrs[versindex].sh_size
1124        / sizeof(struct modversion_info);
1125
1126    for (i = 0; i < num_versions; i++) {
1127        if (strcmp(versions[i].name, symname) != 0)
1128            continue;
1129
1130        if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1131            return 1;
1132        pr_debug("Found checksum %lX vs module %lX\n",
1133               maybe_relocated(*crc, crc_owner), versions[i].crc);
1134        goto bad_version;
1135    }
1136
1137    printk(KERN_WARNING "%s: no symbol version for %s\n",
1138           mod->name, symname);
1139    return 0;
1140
1141bad_version:
1142    printk("%s: disagrees about version of symbol %s\n",
1143           mod->name, symname);
1144    return 0;
1145}
1146
1147static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1148                      unsigned int versindex,
1149                      struct module *mod)
1150{
1151    const unsigned long *crc;
1152
1153    /* Since this should be found in kernel (which can't be removed),
1154     * no locking is necessary. */
1155    if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1156             &crc, true, false))
1157        BUG();
1158    return check_version(sechdrs, versindex, "module_layout", mod, crc,
1159                 NULL);
1160}
1161
1162/* First part is kernel version, which we ignore if module has crcs. */
1163static inline int same_magic(const char *amagic, const char *bmagic,
1164                 bool has_crcs)
1165{
1166    if (has_crcs) {
1167        amagic += strcspn(amagic, " ");
1168        bmagic += strcspn(bmagic, " ");
1169    }
1170    return strcmp(amagic, bmagic) == 0;
1171}
1172#else
1173static inline int check_version(Elf_Shdr *sechdrs,
1174                unsigned int versindex,
1175                const char *symname,
1176                struct module *mod,
1177                const unsigned long *crc,
1178                const struct module *crc_owner)
1179{
1180    return 1;
1181}
1182
1183static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1184                      unsigned int versindex,
1185                      struct module *mod)
1186{
1187    return 1;
1188}
1189
1190static inline int same_magic(const char *amagic, const char *bmagic,
1191                 bool has_crcs)
1192{
1193    return strcmp(amagic, bmagic) == 0;
1194}
1195#endif /* CONFIG_MODVERSIONS */
1196
1197/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1198static const struct kernel_symbol *resolve_symbol(struct module *mod,
1199                          const struct load_info *info,
1200                          const char *name,
1201                          char ownername[])
1202{
1203    struct module *owner;
1204    const struct kernel_symbol *sym;
1205    const unsigned long *crc;
1206    int err;
1207
1208    mutex_lock(&module_mutex);
1209    sym = find_symbol(name, &owner, &crc,
1210              !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1211    if (!sym)
1212        goto unlock;
1213
1214    if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1215               owner)) {
1216        sym = ERR_PTR(-EINVAL);
1217        goto getname;
1218    }
1219
1220    err = ref_module(mod, owner);
1221    if (err) {
1222        sym = ERR_PTR(err);
1223        goto getname;
1224    }
1225
1226getname:
1227    /* We must make copy under the lock if we failed to get ref. */
1228    strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1229unlock:
1230    mutex_unlock(&module_mutex);
1231    return sym;
1232}
1233
1234static const struct kernel_symbol *
1235resolve_symbol_wait(struct module *mod,
1236            const struct load_info *info,
1237            const char *name)
1238{
1239    const struct kernel_symbol *ksym;
1240    char owner[MODULE_NAME_LEN];
1241
1242    if (wait_event_interruptible_timeout(module_wq,
1243            !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1244            || PTR_ERR(ksym) != -EBUSY,
1245                         30 * HZ) <= 0) {
1246        printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1247               mod->name, owner);
1248    }
1249    return ksym;
1250}
1251
1252/*
1253 * /sys/module/foo/sections stuff
1254 * J. Corbet <corbet@lwn.net>
1255 */
1256#ifdef CONFIG_SYSFS
1257
1258#ifdef CONFIG_KALLSYMS
1259static inline bool sect_empty(const Elf_Shdr *sect)
1260{
1261    return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1262}
1263
1264struct module_sect_attr
1265{
1266    struct module_attribute mattr;
1267    char *name;
1268    unsigned long address;
1269};
1270
1271struct module_sect_attrs
1272{
1273    struct attribute_group grp;
1274    unsigned int nsections;
1275    struct module_sect_attr attrs[0];
1276};
1277
1278static ssize_t module_sect_show(struct module_attribute *mattr,
1279                struct module_kobject *mk, char *buf)
1280{
1281    struct module_sect_attr *sattr =
1282        container_of(mattr, struct module_sect_attr, mattr);
1283    return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1284}
1285
1286static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1287{
1288    unsigned int section;
1289
1290    for (section = 0; section < sect_attrs->nsections; section++)
1291        kfree(sect_attrs->attrs[section].name);
1292    kfree(sect_attrs);
1293}
1294
1295static void add_sect_attrs(struct module *mod, const struct load_info *info)
1296{
1297    unsigned int nloaded = 0, i, size[2];
1298    struct module_sect_attrs *sect_attrs;
1299    struct module_sect_attr *sattr;
1300    struct attribute **gattr;
1301
1302    /* Count loaded sections and allocate structures */
1303    for (i = 0; i < info->hdr->e_shnum; i++)
1304        if (!sect_empty(&info->sechdrs[i]))
1305            nloaded++;
1306    size[0] = ALIGN(sizeof(*sect_attrs)
1307            + nloaded * sizeof(sect_attrs->attrs[0]),
1308            sizeof(sect_attrs->grp.attrs[0]));
1309    size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1310    sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1311    if (sect_attrs == NULL)
1312        return;
1313
1314    /* Setup section attributes. */
1315    sect_attrs->grp.name = "sections";
1316    sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1317
1318    sect_attrs->nsections = 0;
1319    sattr = &sect_attrs->attrs[0];
1320    gattr = &sect_attrs->grp.attrs[0];
1321    for (i = 0; i < info->hdr->e_shnum; i++) {
1322        Elf_Shdr *sec = &info->sechdrs[i];
1323        if (sect_empty(sec))
1324            continue;
1325        sattr->address = sec->sh_addr;
1326        sattr->name = kstrdup(info->secstrings + sec->sh_name,
1327                    GFP_KERNEL);
1328        if (sattr->name == NULL)
1329            goto out;
1330        sect_attrs->nsections++;
1331        sysfs_attr_init(&sattr->mattr.attr);
1332        sattr->mattr.show = module_sect_show;
1333        sattr->mattr.store = NULL;
1334        sattr->mattr.attr.name = sattr->name;
1335        sattr->mattr.attr.mode = S_IRUGO;
1336        *(gattr++) = &(sattr++)->mattr.attr;
1337    }
1338    *gattr = NULL;
1339
1340    if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1341        goto out;
1342
1343    mod->sect_attrs = sect_attrs;
1344    return;
1345  out:
1346    free_sect_attrs(sect_attrs);
1347}
1348
1349static void remove_sect_attrs(struct module *mod)
1350{
1351    if (mod->sect_attrs) {
1352        sysfs_remove_group(&mod->mkobj.kobj,
1353                   &mod->sect_attrs->grp);
1354        /* We are positive that no one is using any sect attrs
1355         * at this point. Deallocate immediately. */
1356        free_sect_attrs(mod->sect_attrs);
1357        mod->sect_attrs = NULL;
1358    }
1359}
1360
1361/*
1362 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1363 */
1364
1365struct module_notes_attrs {
1366    struct kobject *dir;
1367    unsigned int notes;
1368    struct bin_attribute attrs[0];
1369};
1370
1371static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1372                 struct bin_attribute *bin_attr,
1373                 char *buf, loff_t pos, size_t count)
1374{
1375    /*
1376     * The caller checked the pos and count against our size.
1377     */
1378    memcpy(buf, bin_attr->private + pos, count);
1379    return count;
1380}
1381
1382static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1383                 unsigned int i)
1384{
1385    if (notes_attrs->dir) {
1386        while (i-- > 0)
1387            sysfs_remove_bin_file(notes_attrs->dir,
1388                          &notes_attrs->attrs[i]);
1389        kobject_put(notes_attrs->dir);
1390    }
1391    kfree(notes_attrs);
1392}
1393
1394static void add_notes_attrs(struct module *mod, const struct load_info *info)
1395{
1396    unsigned int notes, loaded, i;
1397    struct module_notes_attrs *notes_attrs;
1398    struct bin_attribute *nattr;
1399
1400    /* failed to create section attributes, so can't create notes */
1401    if (!mod->sect_attrs)
1402        return;
1403
1404    /* Count notes sections and allocate structures. */
1405    notes = 0;
1406    for (i = 0; i < info->hdr->e_shnum; i++)
1407        if (!sect_empty(&info->sechdrs[i]) &&
1408            (info->sechdrs[i].sh_type == SHT_NOTE))
1409            ++notes;
1410
1411    if (notes == 0)
1412        return;
1413
1414    notes_attrs = kzalloc(sizeof(*notes_attrs)
1415                  + notes * sizeof(notes_attrs->attrs[0]),
1416                  GFP_KERNEL);
1417    if (notes_attrs == NULL)
1418        return;
1419
1420    notes_attrs->notes = notes;
1421    nattr = &notes_attrs->attrs[0];
1422    for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1423        if (sect_empty(&info->sechdrs[i]))
1424            continue;
1425        if (info->sechdrs[i].sh_type == SHT_NOTE) {
1426            sysfs_bin_attr_init(nattr);
1427            nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1428            nattr->attr.mode = S_IRUGO;
1429            nattr->size = info->sechdrs[i].sh_size;
1430            nattr->private = (void *) info->sechdrs[i].sh_addr;
1431            nattr->read = module_notes_read;
1432            ++nattr;
1433        }
1434        ++loaded;
1435    }
1436
1437    notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1438    if (!notes_attrs->dir)
1439        goto out;
1440
1441    for (i = 0; i < notes; ++i)
1442        if (sysfs_create_bin_file(notes_attrs->dir,
1443                      &notes_attrs->attrs[i]))
1444            goto out;
1445
1446    mod->notes_attrs = notes_attrs;
1447    return;
1448
1449  out:
1450    free_notes_attrs(notes_attrs, i);
1451}
1452
1453static void remove_notes_attrs(struct module *mod)
1454{
1455    if (mod->notes_attrs)
1456        free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1457}
1458
1459#else
1460
1461static inline void add_sect_attrs(struct module *mod,
1462                  const struct load_info *info)
1463{
1464}
1465
1466static inline void remove_sect_attrs(struct module *mod)
1467{
1468}
1469
1470static inline void add_notes_attrs(struct module *mod,
1471                   const struct load_info *info)
1472{
1473}
1474
1475static inline void remove_notes_attrs(struct module *mod)
1476{
1477}
1478#endif /* CONFIG_KALLSYMS */
1479
1480static void add_usage_links(struct module *mod)
1481{
1482#ifdef CONFIG_MODULE_UNLOAD
1483    struct module_use *use;
1484    int nowarn;
1485
1486    mutex_lock(&module_mutex);
1487    list_for_each_entry(use, &mod->target_list, target_list) {
1488        nowarn = sysfs_create_link(use->target->holders_dir,
1489                       &mod->mkobj.kobj, mod->name);
1490    }
1491    mutex_unlock(&module_mutex);
1492#endif
1493}
1494
1495static void del_usage_links(struct module *mod)
1496{
1497#ifdef CONFIG_MODULE_UNLOAD
1498    struct module_use *use;
1499
1500    mutex_lock(&module_mutex);
1501    list_for_each_entry(use, &mod->target_list, target_list)
1502        sysfs_remove_link(use->target->holders_dir, mod->name);
1503    mutex_unlock(&module_mutex);
1504#endif
1505}
1506
1507static int module_add_modinfo_attrs(struct module *mod)
1508{
1509    struct module_attribute *attr;
1510    struct module_attribute *temp_attr;
1511    int error = 0;
1512    int i;
1513
1514    mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1515                    (ARRAY_SIZE(modinfo_attrs) + 1)),
1516                    GFP_KERNEL);
1517    if (!mod->modinfo_attrs)
1518        return -ENOMEM;
1519
1520    temp_attr = mod->modinfo_attrs;
1521    for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1522        if (!attr->test ||
1523            (attr->test && attr->test(mod))) {
1524            memcpy(temp_attr, attr, sizeof(*temp_attr));
1525            sysfs_attr_init(&temp_attr->attr);
1526            error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1527            ++temp_attr;
1528        }
1529    }
1530    return error;
1531}
1532
1533static void module_remove_modinfo_attrs(struct module *mod)
1534{
1535    struct module_attribute *attr;
1536    int i;
1537
1538    for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1539        /* pick a field to test for end of list */
1540        if (!attr->attr.name)
1541            break;
1542        sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1543        if (attr->free)
1544            attr->free(mod);
1545    }
1546    kfree(mod->modinfo_attrs);
1547}
1548
1549static int mod_sysfs_init(struct module *mod)
1550{
1551    int err;
1552    struct kobject *kobj;
1553
1554    if (!module_sysfs_initialized) {
1555        printk(KERN_ERR "%s: module sysfs not initialized\n",
1556               mod->name);
1557        err = -EINVAL;
1558        goto out;
1559    }
1560
1561    kobj = kset_find_obj(module_kset, mod->name);
1562    if (kobj) {
1563        printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1564        kobject_put(kobj);
1565        err = -EINVAL;
1566        goto out;
1567    }
1568
1569    mod->mkobj.mod = mod;
1570
1571    memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1572    mod->mkobj.kobj.kset = module_kset;
1573    err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1574                   "%s", mod->name);
1575    if (err)
1576        kobject_put(&mod->mkobj.kobj);
1577
1578    /* delay uevent until full sysfs population */
1579out:
1580    return err;
1581}
1582
1583static int mod_sysfs_setup(struct module *mod,
1584               const struct load_info *info,
1585               struct kernel_param *kparam,
1586               unsigned int num_params)
1587{
1588    int err;
1589
1590    err = mod_sysfs_init(mod);
1591    if (err)
1592        goto out;
1593
1594    mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1595    if (!mod->holders_dir) {
1596        err = -ENOMEM;
1597        goto out_unreg;
1598    }
1599
1600    err = module_param_sysfs_setup(mod, kparam, num_params);
1601    if (err)
1602        goto out_unreg_holders;
1603
1604    err = module_add_modinfo_attrs(mod);
1605    if (err)
1606        goto out_unreg_param;
1607
1608    add_usage_links(mod);
1609    add_sect_attrs(mod, info);
1610    add_notes_attrs(mod, info);
1611
1612    kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1613    return 0;
1614
1615out_unreg_param:
1616    module_param_sysfs_remove(mod);
1617out_unreg_holders:
1618    kobject_put(mod->holders_dir);
1619out_unreg:
1620    kobject_put(&mod->mkobj.kobj);
1621out:
1622    return err;
1623}
1624
1625static void mod_sysfs_fini(struct module *mod)
1626{
1627    remove_notes_attrs(mod);
1628    remove_sect_attrs(mod);
1629    kobject_put(&mod->mkobj.kobj);
1630}
1631
1632#else /* !CONFIG_SYSFS */
1633
1634static int mod_sysfs_setup(struct module *mod,
1635               const struct load_info *info,
1636               struct kernel_param *kparam,
1637               unsigned int num_params)
1638{
1639    return 0;
1640}
1641
1642static void mod_sysfs_fini(struct module *mod)
1643{
1644}
1645
1646static void module_remove_modinfo_attrs(struct module *mod)
1647{
1648}
1649
1650static void del_usage_links(struct module *mod)
1651{
1652}
1653
1654#endif /* CONFIG_SYSFS */
1655
1656static void mod_sysfs_teardown(struct module *mod)
1657{
1658    del_usage_links(mod);
1659    module_remove_modinfo_attrs(mod);
1660    module_param_sysfs_remove(mod);
1661    kobject_put(mod->mkobj.drivers_dir);
1662    kobject_put(mod->holders_dir);
1663    mod_sysfs_fini(mod);
1664}
1665
1666/*
1667 * unlink the module with the whole machine is stopped with interrupts off
1668 * - this defends against kallsyms not taking locks
1669 */
1670static int __unlink_module(void *_mod)
1671{
1672    struct module *mod = _mod;
1673    list_del(&mod->list);
1674    module_bug_cleanup(mod);
1675    return 0;
1676}
1677
1678#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1679/*
1680 * LKM RO/NX protection: protect module's text/ro-data
1681 * from modification and any data from execution.
1682 */
1683void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1684{
1685    unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1686    unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1687
1688    if (end_pfn > begin_pfn)
1689        set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1690}
1691
1692static void set_section_ro_nx(void *base,
1693            unsigned long text_size,
1694            unsigned long ro_size,
1695            unsigned long total_size)
1696{
1697    /* begin and end PFNs of the current subsection */
1698    unsigned long begin_pfn;
1699    unsigned long end_pfn;
1700
1701    /*
1702     * Set RO for module text and RO-data:
1703     * - Always protect first page.
1704     * - Do not protect last partial page.
1705     */
1706    if (ro_size > 0)
1707        set_page_attributes(base, base + ro_size, set_memory_ro);
1708
1709    /*
1710     * Set NX permissions for module data:
1711     * - Do not protect first partial page.
1712     * - Always protect last page.
1713     */
1714    if (total_size > text_size) {
1715        begin_pfn = PFN_UP((unsigned long)base + text_size);
1716        end_pfn = PFN_UP((unsigned long)base + total_size);
1717        if (end_pfn > begin_pfn)
1718            set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1719    }
1720}
1721
1722static void unset_module_core_ro_nx(struct module *mod)
1723{
1724    set_page_attributes(mod->module_core + mod->core_text_size,
1725        mod->module_core + mod->core_size,
1726        set_memory_x);
1727    set_page_attributes(mod->module_core,
1728        mod->module_core + mod->core_ro_size,
1729        set_memory_rw);
1730}
1731
1732static void unset_module_init_ro_nx(struct module *mod)
1733{
1734    set_page_attributes(mod->module_init + mod->init_text_size,
1735        mod->module_init + mod->init_size,
1736        set_memory_x);
1737    set_page_attributes(mod->module_init,
1738        mod->module_init + mod->init_ro_size,
1739        set_memory_rw);
1740}
1741
1742/* Iterate through all modules and set each module's text as RW */
1743void set_all_modules_text_rw(void)
1744{
1745    struct module *mod;
1746
1747    mutex_lock(&module_mutex);
1748    list_for_each_entry_rcu(mod, &modules, list) {
1749        if ((mod->module_core) && (mod->core_text_size)) {
1750            set_page_attributes(mod->module_core,
1751                        mod->module_core + mod->core_text_size,
1752                        set_memory_rw);
1753        }
1754        if ((mod->module_init) && (mod->init_text_size)) {
1755            set_page_attributes(mod->module_init,
1756                        mod->module_init + mod->init_text_size,
1757                        set_memory_rw);
1758        }
1759    }
1760    mutex_unlock(&module_mutex);
1761}
1762
1763/* Iterate through all modules and set each module's text as RO */
1764void set_all_modules_text_ro(void)
1765{
1766    struct module *mod;
1767
1768    mutex_lock(&module_mutex);
1769    list_for_each_entry_rcu(mod, &modules, list) {
1770        if ((mod->module_core) && (mod->core_text_size)) {
1771            set_page_attributes(mod->module_core,
1772                        mod->module_core + mod->core_text_size,
1773                        set_memory_ro);
1774        }
1775        if ((mod->module_init) && (mod->init_text_size)) {
1776            set_page_attributes(mod->module_init,
1777                        mod->module_init + mod->init_text_size,
1778                        set_memory_ro);
1779        }
1780    }
1781    mutex_unlock(&module_mutex);
1782}
1783#else
1784static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1785static void unset_module_core_ro_nx(struct module *mod) { }
1786static void unset_module_init_ro_nx(struct module *mod) { }
1787#endif
1788
1789void __weak module_free(struct module *mod, void *module_region)
1790{
1791    vfree(module_region);
1792}
1793
1794void __weak module_arch_cleanup(struct module *mod)
1795{
1796}
1797
1798/* Free a module, remove from lists, etc. */
1799static void free_module(struct module *mod)
1800{
1801    trace_module_free(mod);
1802
1803    /* Delete from various lists */
1804    mutex_lock(&module_mutex);
1805    stop_machine(__unlink_module, mod, NULL);
1806    mutex_unlock(&module_mutex);
1807    mod_sysfs_teardown(mod);
1808
1809    /* Remove dynamic debug info */
1810    ddebug_remove_module(mod->name);
1811
1812    /* Arch-specific cleanup. */
1813    module_arch_cleanup(mod);
1814
1815    /* Module unload stuff */
1816    module_unload_free(mod);
1817
1818    /* Free any allocated parameters. */
1819    destroy_params(mod->kp, mod->num_kp);
1820
1821    /* This may be NULL, but that's OK */
1822    unset_module_init_ro_nx(mod);
1823    module_free(mod, mod->module_init);
1824    kfree(mod->args);
1825    percpu_modfree(mod);
1826
1827    /* Free lock-classes: */
1828    lockdep_free_key_range(mod->module_core, mod->core_size);
1829
1830    /* Finally, free the core (containing the module structure) */
1831    unset_module_core_ro_nx(mod);
1832    module_free(mod, mod->module_core);
1833
1834#ifdef CONFIG_MPU
1835    update_protections(current->mm);
1836#endif
1837}
1838
1839void *__symbol_get(const char *symbol)
1840{
1841    struct module *owner;
1842    const struct kernel_symbol *sym;
1843
1844    preempt_disable();
1845    sym = find_symbol(symbol, &owner, NULL, true, true);
1846    if (sym && strong_try_module_get(owner))
1847        sym = NULL;
1848    preempt_enable();
1849
1850    return sym ? (void *)sym->value : NULL;
1851}
1852EXPORT_SYMBOL_GPL(__symbol_get);
1853
1854/*
1855 * Ensure that an exported symbol [global namespace] does not already exist
1856 * in the kernel or in some other module's exported symbol table.
1857 *
1858 * You must hold the module_mutex.
1859 */
1860static int verify_export_symbols(struct module *mod)
1861{
1862    unsigned int i;
1863    struct module *owner;
1864    const struct kernel_symbol *s;
1865    struct {
1866        const struct kernel_symbol *sym;
1867        unsigned int num;
1868    } arr[] = {
1869        { mod->syms, mod->num_syms },
1870        { mod->gpl_syms, mod->num_gpl_syms },
1871        { mod->gpl_future_syms, mod->num_gpl_future_syms },
1872#ifdef CONFIG_UNUSED_SYMBOLS
1873        { mod->unused_syms, mod->num_unused_syms },
1874        { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1875#endif
1876    };
1877
1878    for (i = 0; i < ARRAY_SIZE(arr); i++) {
1879        for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1880            if (find_symbol(s->name, &owner, NULL, true, false)) {
1881                printk(KERN_ERR
1882                       "%s: exports duplicate symbol %s"
1883                       " (owned by %s)\n",
1884                       mod->name, s->name, module_name(owner));
1885                return -ENOEXEC;
1886            }
1887        }
1888    }
1889    return 0;
1890}
1891
1892/* Change all symbols so that st_value encodes the pointer directly. */
1893static int simplify_symbols(struct module *mod, const struct load_info *info)
1894{
1895    Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1896    Elf_Sym *sym = (void *)symsec->sh_addr;
1897    unsigned long secbase;
1898    unsigned int i;
1899    int ret = 0;
1900    const struct kernel_symbol *ksym;
1901
1902    for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1903        const char *name = info->strtab + sym[i].st_name;
1904
1905        switch (sym[i].st_shndx) {
1906        case SHN_COMMON:
1907            /* We compiled with -fno-common. These are not
1908               supposed to happen. */
1909            pr_debug("Common symbol: %s\n", name);
1910            printk("%s: please compile with -fno-common\n",
1911                   mod->name);
1912            ret = -ENOEXEC;
1913            break;
1914
1915        case SHN_ABS:
1916            /* Don't need to do anything */
1917            pr_debug("Absolute symbol: 0x%08lx\n",
1918                   (long)sym[i].st_value);
1919            break;
1920
1921        case SHN_UNDEF:
1922            ksym = resolve_symbol_wait(mod, info, name);
1923            /* Ok if resolved. */
1924            if (ksym && !IS_ERR(ksym)) {
1925                sym[i].st_value = ksym->value;
1926                break;
1927            }
1928
1929            /* Ok if weak. */
1930            if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1931                break;
1932
1933            printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1934                   mod->name, name, PTR_ERR(ksym));
1935            ret = PTR_ERR(ksym) ?: -ENOENT;
1936            break;
1937
1938        default:
1939            /* Divert to percpu allocation if a percpu var. */
1940            if (sym[i].st_shndx == info->index.pcpu)
1941                secbase = (unsigned long)mod_percpu(mod);
1942            else
1943                secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1944            sym[i].st_value += secbase;
1945            break;
1946        }
1947    }
1948
1949    return ret;
1950}
1951
1952int __weak apply_relocate(Elf_Shdr *sechdrs,
1953              const char *strtab,
1954              unsigned int symindex,
1955              unsigned int relsec,
1956              struct module *me)
1957{
1958    pr_err("module %s: REL relocation unsupported\n", me->name);
1959    return -ENOEXEC;
1960}
1961
1962int __weak apply_relocate_add(Elf_Shdr *sechdrs,
1963                  const char *strtab,
1964                  unsigned int symindex,
1965                  unsigned int relsec,
1966                  struct module *me)
1967{
1968    pr_err("module %s: RELA relocation unsupported\n", me->name);
1969    return -ENOEXEC;
1970}
1971
1972static int apply_relocations(struct module *mod, const struct load_info *info)
1973{
1974    unsigned int i;
1975    int err = 0;
1976
1977    /* Now do relocations. */
1978    for (i = 1; i < info->hdr->e_shnum; i++) {
1979        unsigned int infosec = info->sechdrs[i].sh_info;
1980
1981        /* Not a valid relocation section? */
1982        if (infosec >= info->hdr->e_shnum)
1983            continue;
1984
1985        /* Don't bother with non-allocated sections */
1986        if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1987            continue;
1988
1989        if (info->sechdrs[i].sh_type == SHT_REL)
1990            err = apply_relocate(info->sechdrs, info->strtab,
1991                         info->index.sym, i, mod);
1992        else if (info->sechdrs[i].sh_type == SHT_RELA)
1993            err = apply_relocate_add(info->sechdrs, info->strtab,
1994                         info->index.sym, i, mod);
1995        if (err < 0)
1996            break;
1997    }
1998    return err;
1999}
2000
2001/* Additional bytes needed by arch in front of individual sections */
2002unsigned int __weak arch_mod_section_prepend(struct module *mod,
2003                         unsigned int section)
2004{
2005    /* default implementation just returns zero */
2006    return 0;
2007}
2008
2009/* Update size with this section: return offset. */
2010static long get_offset(struct module *mod, unsigned int *size,
2011               Elf_Shdr *sechdr, unsigned int section)
2012{
2013    long ret;
2014
2015    *size += arch_mod_section_prepend(mod, section);
2016    ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2017    *size = ret + sechdr->sh_size;
2018    return ret;
2019}
2020
2021/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2022   might -- code, read-only data, read-write data, small data. Tally
2023   sizes, and place the offsets into sh_entsize fields: high bit means it
2024   belongs in init. */
2025static void layout_sections(struct module *mod, struct load_info *info)
2026{
2027    static unsigned long const masks[][2] = {
2028        /* NOTE: all executable code must be the first section
2029         * in this array; otherwise modify the text_size
2030         * finder in the two loops below */
2031        { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2032        { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2033        { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2034        { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2035    };
2036    unsigned int m, i;
2037
2038    for (i = 0; i < info->hdr->e_shnum; i++)
2039        info->sechdrs[i].sh_entsize = ~0UL;
2040
2041    pr_debug("Core section allocation order:\n");
2042    for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2043        for (i = 0; i < info->hdr->e_shnum; ++i) {
2044            Elf_Shdr *s = &info->sechdrs[i];
2045            const char *sname = info->secstrings + s->sh_name;
2046
2047            if ((s->sh_flags & masks[m][0]) != masks[m][0]
2048                || (s->sh_flags & masks[m][1])
2049                || s->sh_entsize != ~0UL
2050                || strstarts(sname, ".init"))
2051                continue;
2052            s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2053            pr_debug("\t%s\n", sname);
2054        }
2055        switch (m) {
2056        case 0: /* executable */
2057            mod->core_size = debug_align(mod->core_size);
2058            mod->core_text_size = mod->core_size;
2059            break;
2060        case 1: /* RO: text and ro-data */
2061            mod->core_size = debug_align(mod->core_size);
2062            mod->core_ro_size = mod->core_size;
2063            break;
2064        case 3: /* whole core */
2065            mod->core_size = debug_align(mod->core_size);
2066            break;
2067        }
2068    }
2069
2070    pr_debug("Init section allocation order:\n");
2071    for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2072        for (i = 0; i < info->hdr->e_shnum; ++i) {
2073            Elf_Shdr *s = &info->sechdrs[i];
2074            const char *sname = info->secstrings + s->sh_name;
2075
2076            if ((s->sh_flags & masks[m][0]) != masks[m][0]
2077                || (s->sh_flags & masks[m][1])
2078                || s->sh_entsize != ~0UL
2079                || !strstarts(sname, ".init"))
2080                continue;
2081            s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2082                     | INIT_OFFSET_MASK);
2083            pr_debug("\t%s\n", sname);
2084        }
2085        switch (m) {
2086        case 0: /* executable */
2087            mod->init_size = debug_align(mod->init_size);
2088            mod->init_text_size = mod->init_size;
2089            break;
2090        case 1: /* RO: text and ro-data */
2091            mod->init_size = debug_align(mod->init_size);
2092            mod->init_ro_size = mod->init_size;
2093            break;
2094        case 3: /* whole init */
2095            mod->init_size = debug_align(mod->init_size);
2096            break;
2097        }
2098    }
2099}
2100
2101static void set_license(struct module *mod, const char *license)
2102{
2103    if (!license)
2104        license = "unspecified";
2105
2106    if (!license_is_gpl_compatible(license)) {
2107        if (!test_taint(TAINT_PROPRIETARY_MODULE))
2108            printk(KERN_WARNING "%s: module license '%s' taints "
2109                "kernel.\n", mod->name, license);
2110        add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2111    }
2112}
2113
2114/* Parse tag=value strings from .modinfo section */
2115static char *next_string(char *string, unsigned long *secsize)
2116{
2117    /* Skip non-zero chars */
2118    while (string[0]) {
2119        string++;
2120        if ((*secsize)-- <= 1)
2121            return NULL;
2122    }
2123
2124    /* Skip any zero padding. */
2125    while (!string[0]) {
2126        string++;
2127        if ((*secsize)-- <= 1)
2128            return NULL;
2129    }
2130    return string;
2131}
2132
2133static char *get_modinfo(struct load_info *info, const char *tag)
2134{
2135    char *p;
2136    unsigned int taglen = strlen(tag);
2137    Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2138    unsigned long size = infosec->sh_size;
2139
2140    for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2141        if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2142            return p + taglen + 1;
2143    }
2144    return NULL;
2145}
2146
2147static void setup_modinfo(struct module *mod, struct load_info *info)
2148{
2149    struct module_attribute *attr;
2150    int i;
2151
2152    for (i = 0; (attr = modinfo_attrs[i]); i++) {
2153        if (attr->setup)
2154            attr->setup(mod, get_modinfo(info, attr->attr.name));
2155    }
2156}
2157
2158static void free_modinfo(struct module *mod)
2159{
2160    struct module_attribute *attr;
2161    int i;
2162
2163    for (i = 0; (attr = modinfo_attrs[i]); i++) {
2164        if (attr->free)
2165            attr->free(mod);
2166    }
2167}
2168
2169#ifdef CONFIG_KALLSYMS
2170
2171/* lookup symbol in given range of kernel_symbols */
2172static const struct kernel_symbol *lookup_symbol(const char *name,
2173    const struct kernel_symbol *start,
2174    const struct kernel_symbol *stop)
2175{
2176    return bsearch(name, start, stop - start,
2177            sizeof(struct kernel_symbol), cmp_name);
2178}
2179
2180static int is_exported(const char *name, unsigned long value,
2181               const struct module *mod)
2182{
2183    const struct kernel_symbol *ks;
2184    if (!mod)
2185        ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2186    else
2187        ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2188    return ks != NULL && ks->value == value;
2189}
2190
2191/* As per nm */
2192static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2193{
2194    const Elf_Shdr *sechdrs = info->sechdrs;
2195
2196    if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2197        if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2198            return 'v';
2199        else
2200            return 'w';
2201    }
2202    if (sym->st_shndx == SHN_UNDEF)
2203        return 'U';
2204    if (sym->st_shndx == SHN_ABS)
2205        return 'a';
2206    if (sym->st_shndx >= SHN_LORESERVE)
2207        return '?';
2208    if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2209        return 't';
2210    if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2211        && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2212        if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2213            return 'r';
2214        else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2215            return 'g';
2216        else
2217            return 'd';
2218    }
2219    if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2220        if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2221            return 's';
2222        else
2223            return 'b';
2224    }
2225    if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2226              ".debug")) {
2227        return 'n';
2228    }
2229    return '?';
2230}
2231
2232static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2233                           unsigned int shnum)
2234{
2235    const Elf_Shdr *sec;
2236
2237    if (src->st_shndx == SHN_UNDEF
2238        || src->st_shndx >= shnum
2239        || !src->st_name)
2240        return false;
2241
2242    sec = sechdrs + src->st_shndx;
2243    if (!(sec->sh_flags & SHF_ALLOC)
2244#ifndef CONFIG_KALLSYMS_ALL
2245        || !(sec->sh_flags & SHF_EXECINSTR)
2246#endif
2247        || (sec->sh_entsize & INIT_OFFSET_MASK))
2248        return false;
2249
2250    return true;
2251}
2252
2253/*
2254 * We only allocate and copy the strings needed by the parts of symtab
2255 * we keep. This is simple, but has the effect of making multiple
2256 * copies of duplicates. We could be more sophisticated, see
2257 * linux-kernel thread starting with
2258 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2259 */
2260static void layout_symtab(struct module *mod, struct load_info *info)
2261{
2262    Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2263    Elf_Shdr *strsect = info->sechdrs + info->index.str;
2264    const Elf_Sym *src;
2265    unsigned int i, nsrc, ndst, strtab_size;
2266
2267    /* Put symbol section at end of init part of module. */
2268    symsect->sh_flags |= SHF_ALLOC;
2269    symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2270                     info->index.sym) | INIT_OFFSET_MASK;
2271    pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2272
2273    src = (void *)info->hdr + symsect->sh_offset;
2274    nsrc = symsect->sh_size / sizeof(*src);
2275
2276    /* Compute total space required for the core symbols' strtab. */
2277    for (ndst = i = strtab_size = 1; i < nsrc; ++i, ++src)
2278        if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
2279            strtab_size += strlen(&info->strtab[src->st_name]) + 1;
2280            ndst++;
2281        }
2282
2283    /* Append room for core symbols at end of core part. */
2284    info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2285    info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2286    mod->core_size += strtab_size;
2287
2288    /* Put string table section at end of init part of module. */
2289    strsect->sh_flags |= SHF_ALLOC;
2290    strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2291                     info->index.str) | INIT_OFFSET_MASK;
2292    pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2293}
2294
2295static void add_kallsyms(struct module *mod, const struct load_info *info)
2296{
2297    unsigned int i, ndst;
2298    const Elf_Sym *src;
2299    Elf_Sym *dst;
2300    char *s;
2301    Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2302
2303    mod->symtab = (void *)symsec->sh_addr;
2304    mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2305    /* Make sure we get permanent strtab: don't use info->strtab. */
2306    mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2307
2308    /* Set types up while we still have access to sections. */
2309    for (i = 0; i < mod->num_symtab; i++)
2310        mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2311
2312    mod->core_symtab = dst = mod->module_core + info->symoffs;
2313    mod->core_strtab = s = mod->module_core + info->stroffs;
2314    src = mod->symtab;
2315    *dst = *src;
2316    *s++ = 0;
2317    for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2318        if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2319            continue;
2320
2321        dst[ndst] = *src;
2322        dst[ndst++].st_name = s - mod->core_strtab;
2323        s += strlcpy(s, &mod->strtab[src->st_name], KSYM_NAME_LEN) + 1;
2324    }
2325    mod->core_num_syms = ndst;
2326}
2327#else
2328static inline void layout_symtab(struct module *mod, struct load_info *info)
2329{
2330}
2331
2332static void add_kallsyms(struct module *mod, const struct load_info *info)
2333{
2334}
2335#endif /* CONFIG_KALLSYMS */
2336
2337static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2338{
2339    if (!debug)
2340        return;
2341#ifdef CONFIG_DYNAMIC_DEBUG
2342    if (ddebug_add_module(debug, num, debug->modname))
2343        printk(KERN_ERR "dynamic debug error adding module: %s\n",
2344                    debug->modname);
2345#endif
2346}
2347
2348static void dynamic_debug_remove(struct _ddebug *debug)
2349{
2350    if (debug)
2351        ddebug_remove_module(debug->modname);
2352}
2353
2354void * __weak module_alloc(unsigned long size)
2355{
2356    return size == 0 ? NULL : vmalloc_exec(size);
2357}
2358
2359static void *module_alloc_update_bounds(unsigned long size)
2360{
2361    void *ret = module_alloc(size);
2362
2363    if (ret) {
2364        mutex_lock(&module_mutex);
2365        /* Update module bounds. */
2366        if ((unsigned long)ret < module_addr_min)
2367            module_addr_min = (unsigned long)ret;
2368        if ((unsigned long)ret + size > module_addr_max)
2369            module_addr_max = (unsigned long)ret + size;
2370        mutex_unlock(&module_mutex);
2371    }
2372    return ret;
2373}
2374
2375#ifdef CONFIG_DEBUG_KMEMLEAK
2376static void kmemleak_load_module(const struct module *mod,
2377                 const struct load_info *info)
2378{
2379    unsigned int i;
2380
2381    /* only scan the sections containing data */
2382    kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2383
2384    for (i = 1; i < info->hdr->e_shnum; i++) {
2385        const char *name = info->secstrings + info->sechdrs[i].sh_name;
2386        if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2387            continue;
2388        if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2389            continue;
2390
2391        kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2392                   info->sechdrs[i].sh_size, GFP_KERNEL);
2393    }
2394}
2395#else
2396static inline void kmemleak_load_module(const struct module *mod,
2397                    const struct load_info *info)
2398{
2399}
2400#endif
2401
2402/* Sets info->hdr and info->len. */
2403static int copy_and_check(struct load_info *info,
2404              const void __user *umod, unsigned long len,
2405              const char __user *uargs)
2406{
2407    int err;
2408    Elf_Ehdr *hdr;
2409
2410    if (len < sizeof(*hdr))
2411        return -ENOEXEC;
2412
2413    /* Suck in entire file: we'll want most of it. */
2414    if ((hdr = vmalloc(len)) == NULL)
2415        return -ENOMEM;
2416
2417    if (copy_from_user(hdr, umod, len) != 0) {
2418        err = -EFAULT;
2419        goto free_hdr;
2420    }
2421
2422    /* Sanity checks against insmoding binaries or wrong arch,
2423       weird elf version */
2424    if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2425        || hdr->e_type != ET_REL
2426        || !elf_check_arch(hdr)
2427        || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2428        err = -ENOEXEC;
2429        goto free_hdr;
2430    }
2431
2432    if (hdr->e_shoff >= len ||
2433        hdr->e_shnum * sizeof(Elf_Shdr) > len - hdr->e_shoff) {
2434        err = -ENOEXEC;
2435        goto free_hdr;
2436    }
2437
2438    info->hdr = hdr;
2439    info->len = len;
2440    return 0;
2441
2442free_hdr:
2443    vfree(hdr);
2444    return err;
2445}
2446
2447static void free_copy(struct load_info *info)
2448{
2449    vfree(info->hdr);
2450}
2451
2452static int rewrite_section_headers(struct load_info *info)
2453{
2454    unsigned int i;
2455
2456    /* This should always be true, but let's be sure. */
2457    info->sechdrs[0].sh_addr = 0;
2458
2459    for (i = 1; i < info->hdr->e_shnum; i++) {
2460        Elf_Shdr *shdr = &info->sechdrs[i];
2461        if (shdr->sh_type != SHT_NOBITS
2462            && info->len < shdr->sh_offset + shdr->sh_size) {
2463            printk(KERN_ERR "Module len %lu truncated\n",
2464                   info->len);
2465            return -ENOEXEC;
2466        }
2467
2468        /* Mark all sections sh_addr with their address in the
2469           temporary image. */
2470        shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2471
2472#ifndef CONFIG_MODULE_UNLOAD
2473        /* Don't load .exit sections */
2474        if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2475            shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2476#endif
2477    }
2478
2479    /* Track but don't keep modinfo and version sections. */
2480    info->index.vers = find_sec(info, "__versions");
2481    info->index.info = find_sec(info, ".modinfo");
2482    info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2483    info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2484    return 0;
2485}
2486
2487/*
2488 * Set up our basic convenience variables (pointers to section headers,
2489 * search for module section index etc), and do some basic section
2490 * verification.
2491 *
2492 * Return the temporary module pointer (we'll replace it with the final
2493 * one when we move the module sections around).
2494 */
2495static struct module *setup_load_info(struct load_info *info)
2496{
2497    unsigned int i;
2498    int err;
2499    struct module *mod;
2500
2501    /* Set up the convenience variables */
2502    info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2503    info->secstrings = (void *)info->hdr
2504        + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2505
2506    err = rewrite_section_headers(info);
2507    if (err)
2508        return ERR_PTR(err);
2509
2510    /* Find internal symbols and strings. */
2511    for (i = 1; i < info->hdr->e_shnum; i++) {
2512        if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2513            info->index.sym = i;
2514            info->index.str = info->sechdrs[i].sh_link;
2515            info->strtab = (char *)info->hdr
2516                + info->sechdrs[info->index.str].sh_offset;
2517            break;
2518        }
2519    }
2520
2521    info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2522    if (!info->index.mod) {
2523        printk(KERN_WARNING "No module found in object\n");
2524        return ERR_PTR(-ENOEXEC);
2525    }
2526    /* This is temporary: point mod into copy of data. */
2527    mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2528
2529    if (info->index.sym == 0) {
2530        printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2531               mod->name);
2532        return ERR_PTR(-ENOEXEC);
2533    }
2534
2535    info->index.pcpu = find_pcpusec(info);
2536
2537    /* Check module struct version now, before we try to use module. */
2538    if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2539        return ERR_PTR(-ENOEXEC);
2540
2541    return mod;
2542}
2543
2544static int check_modinfo(struct module *mod, struct load_info *info)
2545{
2546    const char *modmagic = get_modinfo(info, "vermagic");
2547    int err;
2548
2549    /* This is allowed: modprobe --force will invalidate it. */
2550    if (!modmagic) {
2551        err = try_to_force_load(mod, "bad vermagic");
2552        if (err)
2553            return err;
2554    } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2555        printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2556               mod->name, modmagic, vermagic);
2557        return -ENOEXEC;
2558    }
2559
2560    if (!get_modinfo(info, "intree"))
2561        add_taint_module(mod, TAINT_OOT_MODULE);
2562
2563    if (get_modinfo(info, "staging")) {
2564        add_taint_module(mod, TAINT_CRAP);
2565        printk(KERN_WARNING "%s: module is from the staging directory,"
2566               " the quality is unknown, you have been warned.\n",
2567               mod->name);
2568    }
2569
2570    /* Set up license info based on the info section */
2571    set_license(mod, get_modinfo(info, "license"));
2572
2573    return 0;
2574}
2575
2576static void find_module_sections(struct module *mod, struct load_info *info)
2577{
2578    mod->kp = section_objs(info, "__param",
2579                   sizeof(*mod->kp), &mod->num_kp);
2580    mod->syms = section_objs(info, "__ksymtab",
2581                 sizeof(*mod->syms), &mod->num_syms);
2582    mod->crcs = section_addr(info, "__kcrctab");
2583    mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2584                     sizeof(*mod->gpl_syms),
2585                     &mod->num_gpl_syms);
2586    mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2587    mod->gpl_future_syms = section_objs(info,
2588                        "__ksymtab_gpl_future",
2589                        sizeof(*mod->gpl_future_syms),
2590                        &mod->num_gpl_future_syms);
2591    mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2592
2593#ifdef CONFIG_UNUSED_SYMBOLS
2594    mod->unused_syms = section_objs(info, "__ksymtab_unused",
2595                    sizeof(*mod->unused_syms),
2596                    &mod->num_unused_syms);
2597    mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2598    mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2599                        sizeof(*mod->unused_gpl_syms),
2600                        &mod->num_unused_gpl_syms);
2601    mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2602#endif
2603#ifdef CONFIG_CONSTRUCTORS
2604    mod->ctors = section_objs(info, ".ctors",
2605                  sizeof(*mod->ctors), &mod->num_ctors);
2606#endif
2607
2608#ifdef CONFIG_TRACEPOINTS
2609    mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2610                         sizeof(*mod->tracepoints_ptrs),
2611                         &mod->num_tracepoints);
2612#endif
2613#ifdef HAVE_JUMP_LABEL
2614    mod->jump_entries = section_objs(info, "__jump_table",
2615                    sizeof(*mod->jump_entries),
2616                    &mod->num_jump_entries);
2617#endif
2618#ifdef CONFIG_EVENT_TRACING
2619    mod->trace_events = section_objs(info, "_ftrace_events",
2620                     sizeof(*mod->trace_events),
2621                     &mod->num_trace_events);
2622    /*
2623     * This section contains pointers to allocated objects in the trace
2624     * code and not scanning it leads to false positives.
2625     */
2626    kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2627               mod->num_trace_events, GFP_KERNEL);
2628#endif
2629#ifdef CONFIG_TRACING
2630    mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2631                     sizeof(*mod->trace_bprintk_fmt_start),
2632                     &mod->num_trace_bprintk_fmt);
2633    /*
2634     * This section contains pointers to allocated objects in the trace
2635     * code and not scanning it leads to false positives.
2636     */
2637    kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2638               sizeof(*mod->trace_bprintk_fmt_start) *
2639               mod->num_trace_bprintk_fmt, GFP_KERNEL);
2640#endif
2641#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2642    /* sechdrs[0].sh_size is always zero */
2643    mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2644                         sizeof(*mod->ftrace_callsites),
2645                         &mod->num_ftrace_callsites);
2646#endif
2647
2648    mod->extable = section_objs(info, "__ex_table",
2649                    sizeof(*mod->extable), &mod->num_exentries);
2650
2651    if (section_addr(info, "__obsparm"))
2652        printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2653               mod->name);
2654
2655    info->debug = section_objs(info, "__verbose",
2656                   sizeof(*info->debug), &info->num_debug);
2657}
2658
2659static int move_module(struct module *mod, struct load_info *info)
2660{
2661    int i;
2662    void *ptr;
2663
2664    /* Do the allocs. */
2665    ptr = module_alloc_update_bounds(mod->core_size);
2666    /*
2667     * The pointer to this block is stored in the module structure
2668     * which is inside the block. Just mark it as not being a
2669     * leak.
2670     */
2671    kmemleak_not_leak(ptr);
2672    if (!ptr)
2673        return -ENOMEM;
2674
2675    memset(ptr, 0, mod->core_size);
2676    mod->module_core = ptr;
2677
2678    ptr = module_alloc_update_bounds(mod->init_size);
2679    /*
2680     * The pointer to this block is stored in the module structure
2681     * which is inside the block. This block doesn't need to be
2682     * scanned as it contains data and code that will be freed
2683     * after the module is initialized.
2684     */
2685    kmemleak_ignore(ptr);
2686    if (!ptr && mod->init_size) {
2687        module_free(mod, mod->module_core);
2688        return -ENOMEM;
2689    }
2690    memset(ptr, 0, mod->init_size);
2691    mod->module_init = ptr;
2692
2693    /* Transfer each section which specifies SHF_ALLOC */
2694    pr_debug("final section addresses:\n");
2695    for (i = 0; i < info->hdr->e_shnum; i++) {
2696        void *dest;
2697        Elf_Shdr *shdr = &info->sechdrs[i];
2698
2699        if (!(shdr->sh_flags & SHF_ALLOC))
2700            continue;
2701
2702        if (shdr->sh_entsize & INIT_OFFSET_MASK)
2703            dest = mod->module_init
2704                + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2705        else
2706            dest = mod->module_core + shdr->sh_entsize;
2707
2708        if (shdr->sh_type != SHT_NOBITS)
2709            memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2710        /* Update sh_addr to point to copy in image. */
2711        shdr->sh_addr = (unsigned long)dest;
2712        pr_debug("\t0x%lx %s\n",
2713             (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2714    }
2715
2716    return 0;
2717}
2718
2719static int check_module_license_and_versions(struct module *mod)
2720{
2721    /*
2722     * ndiswrapper is under GPL by itself, but loads proprietary modules.
2723     * Don't use add_taint_module(), as it would prevent ndiswrapper from
2724     * using GPL-only symbols it needs.
2725     */
2726    if (strcmp(mod->name, "ndiswrapper") == 0)
2727        add_taint(TAINT_PROPRIETARY_MODULE);
2728
2729    /* driverloader was caught wrongly pretending to be under GPL */
2730    if (strcmp(mod->name, "driverloader") == 0)
2731        add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2732
2733#ifdef CONFIG_MODVERSIONS
2734    if ((mod->num_syms && !mod->crcs)
2735        || (mod->num_gpl_syms && !mod->gpl_crcs)
2736        || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2737#ifdef CONFIG_UNUSED_SYMBOLS
2738        || (mod->num_unused_syms && !mod->unused_crcs)
2739        || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2740#endif
2741        ) {
2742        return try_to_force_load(mod,
2743                     "no versions for exported symbols");
2744    }
2745#endif
2746    return 0;
2747}
2748
2749static void flush_module_icache(const struct module *mod)
2750{
2751    mm_segment_t old_fs;
2752
2753    /* flush the icache in correct context */
2754    old_fs = get_fs();
2755    set_fs(KERNEL_DS);
2756
2757    /*
2758     * Flush the instruction cache, since we've played with text.
2759     * Do it before processing of module parameters, so the module
2760     * can provide parameter accessor functions of its own.
2761     */
2762    if (mod->module_init)
2763        flush_icache_range((unsigned long)mod->module_init,
2764                   (unsigned long)mod->module_init
2765                   + mod->init_size);
2766    flush_icache_range((unsigned long)mod->module_core,
2767               (unsigned long)mod->module_core + mod->core_size);
2768
2769    set_fs(old_fs);
2770}
2771
2772int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2773                     Elf_Shdr *sechdrs,
2774                     char *secstrings,
2775                     struct module *mod)
2776{
2777    return 0;
2778}
2779
2780static struct module *layout_and_allocate(struct load_info *info)
2781{
2782    /* Module within temporary copy. */
2783    struct module *mod;
2784    Elf_Shdr *pcpusec;
2785    int err;
2786
2787    mod = setup_load_info(info);
2788    if (IS_ERR(mod))
2789        return mod;
2790
2791    err = check_modinfo(mod, info);
2792    if (err)
2793        return ERR_PTR(err);
2794
2795    /* Allow arches to frob section contents and sizes. */
2796    err = module_frob_arch_sections(info->hdr, info->sechdrs,
2797                    info->secstrings, mod);
2798    if (err < 0)
2799        goto out;
2800
2801    pcpusec = &info->sechdrs[info->index.pcpu];
2802    if (pcpusec->sh_size) {
2803        /* We have a special allocation for this section. */
2804        err = percpu_modalloc(mod,
2805                      pcpusec->sh_size, pcpusec->sh_addralign);
2806        if (err)
2807            goto out;
2808        pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2809    }
2810
2811    /* Determine total sizes, and put offsets in sh_entsize. For now
2812       this is done generically; there doesn't appear to be any
2813       special cases for the architectures. */
2814    layout_sections(mod, info);
2815    layout_symtab(mod, info);
2816
2817    /* Allocate and move to the final place */
2818    err = move_module(mod, info);
2819    if (err)
2820        goto free_percpu;
2821
2822    /* Module has been copied to its final place now: return it. */
2823    mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2824    kmemleak_load_module(mod, info);
2825    return mod;
2826
2827free_percpu:
2828    percpu_modfree(mod);
2829out:
2830    return ERR_PTR(err);
2831}
2832
2833/* mod is no longer valid after this! */
2834static void module_deallocate(struct module *mod, struct load_info *info)
2835{
2836    percpu_modfree(mod);
2837    module_free(mod, mod->module_init);
2838    module_free(mod, mod->module_core);
2839}
2840
2841int __weak module_finalize(const Elf_Ehdr *hdr,
2842               const Elf_Shdr *sechdrs,
2843               struct module *me)
2844{
2845    return 0;
2846}
2847
2848static int post_relocation(struct module *mod, const struct load_info *info)
2849{
2850    /* Sort exception table now relocations are done. */
2851    sort_extable(mod->extable, mod->extable + mod->num_exentries);
2852
2853    /* Copy relocated percpu area over. */
2854    percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2855               info->sechdrs[info->index.pcpu].sh_size);
2856
2857    /* Setup kallsyms-specific fields. */
2858    add_kallsyms(mod, info);
2859
2860    /* Arch-specific module finalizing. */
2861    return module_finalize(info->hdr, info->sechdrs, mod);
2862}
2863
2864/* Allocate and load the module: note that size of section 0 is always
2865   zero, and we rely on this for optional sections. */
2866static struct module *load_module(void __user *umod,
2867                  unsigned long len,
2868                  const char __user *uargs)
2869{
2870    struct load_info info = { NULL, };
2871    struct module *mod;
2872    long err;
2873
2874    pr_debug("load_module: umod=%p, len=%lu, uargs=%p\n",
2875           umod, len, uargs);
2876
2877    /* Copy in the blobs from userspace, check they are vaguely sane. */
2878    err = copy_and_check(&info, umod, len, uargs);
2879    if (err)
2880        return ERR_PTR(err);
2881
2882    /* Figure out module layout, and allocate all the memory. */
2883    mod = layout_and_allocate(&info);
2884    if (IS_ERR(mod)) {
2885        err = PTR_ERR(mod);
2886        goto free_copy;
2887    }
2888
2889    /* Now module is in final location, initialize linked lists, etc. */
2890    err = module_unload_init(mod);
2891    if (err)
2892        goto free_module;
2893
2894    /* Now we've got everything in the final locations, we can
2895     * find optional sections. */
2896    find_module_sections(mod, &info);
2897
2898    err = check_module_license_and_versions(mod);
2899    if (err)
2900        goto free_unload;
2901
2902    /* Set up MODINFO_ATTR fields */
2903    setup_modinfo(mod, &info);
2904
2905    /* Fix up syms, so that st_value is a pointer to location. */
2906    err = simplify_symbols(mod, &info);
2907    if (err < 0)
2908        goto free_modinfo;
2909
2910    err = apply_relocations(mod, &info);
2911    if (err < 0)
2912        goto free_modinfo;
2913
2914    err = post_relocation(mod, &info);
2915    if (err < 0)
2916        goto free_modinfo;
2917
2918    flush_module_icache(mod);
2919
2920    /* Now copy in args */
2921    mod->args = strndup_user(uargs, ~0UL >> 1);
2922    if (IS_ERR(mod->args)) {
2923        err = PTR_ERR(mod->args);
2924        goto free_arch_cleanup;
2925    }
2926
2927    /* Mark state as coming so strong_try_module_get() ignores us. */
2928    mod->state = MODULE_STATE_COMING;
2929
2930    /* Now sew it into the lists so we can get lockdep and oops
2931     * info during argument parsing. No one should access us, since
2932     * strong_try_module_get() will fail.
2933     * lockdep/oops can run asynchronous, so use the RCU list insertion
2934     * function to insert in a way safe to concurrent readers.
2935     * The mutex protects against concurrent writers.
2936     */
2937    mutex_lock(&module_mutex);
2938    if (find_module(mod->name)) {
2939        err = -EEXIST;
2940        goto unlock;
2941    }
2942
2943    /* This has to be done once we're sure module name is unique. */
2944    dynamic_debug_setup(info.debug, info.num_debug);
2945
2946    /* Find duplicate symbols */
2947    err = verify_export_symbols(mod);
2948    if (err < 0)
2949        goto ddebug;
2950
2951    module_bug_finalize(info.hdr, info.sechdrs, mod);
2952    list_add_rcu(&mod->list, &modules);
2953    mutex_unlock(&module_mutex);
2954
2955    /* Module is ready to execute: parsing args may do that. */
2956    err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
2957             -32768, 32767, &ddebug_dyndbg_module_param_cb);
2958    if (err < 0)
2959        goto unlink;
2960
2961    /* Link in to syfs. */
2962    err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2963    if (err < 0)
2964        goto unlink;
2965
2966    /* Get rid of temporary copy. */
2967    free_copy(&info);
2968
2969    /* Done! */
2970    trace_module_load(mod);
2971    return mod;
2972
2973 unlink:
2974    mutex_lock(&module_mutex);
2975    /* Unlink carefully: kallsyms could be walking list. */
2976    list_del_rcu(&mod->list);
2977    module_bug_cleanup(mod);
2978
2979 ddebug:
2980    dynamic_debug_remove(info.debug);
2981 unlock:
2982    mutex_unlock(&module_mutex);
2983    synchronize_sched();
2984    kfree(mod->args);
2985 free_arch_cleanup:
2986    module_arch_cleanup(mod);
2987 free_modinfo:
2988    free_modinfo(mod);
2989 free_unload:
2990    module_unload_free(mod);
2991 free_module:
2992    module_deallocate(mod, &info);
2993 free_copy:
2994    free_copy(&info);
2995    return ERR_PTR(err);
2996}
2997
2998/* Call module constructors. */
2999static void do_mod_ctors(struct module *mod)
3000{
3001#ifdef CONFIG_CONSTRUCTORS
3002    unsigned long i;
3003
3004    for (i = 0; i < mod->num_ctors; i++)
3005        mod->ctors[i]();
3006#endif
3007}
3008
3009/* This is where the real work happens */
3010SYSCALL_DEFINE3(init_module, void __user *, umod,
3011        unsigned long, len, const char __user *, uargs)
3012{
3013    struct module *mod;
3014    int ret = 0;
3015
3016    /* Must have permission */
3017    if (!capable(CAP_SYS_MODULE) || modules_disabled)
3018        return -EPERM;
3019
3020    /* Do all the hard work */
3021    mod = load_module(umod, len, uargs);
3022    if (IS_ERR(mod))
3023        return PTR_ERR(mod);
3024
3025    blocking_notifier_call_chain(&module_notify_list,
3026            MODULE_STATE_COMING, mod);
3027
3028    /* Set RO and NX regions for core */
3029    set_section_ro_nx(mod->module_core,
3030                mod->core_text_size,
3031                mod->core_ro_size,
3032                mod->core_size);
3033
3034    /* Set RO and NX regions for init */
3035    set_section_ro_nx(mod->module_init,
3036                mod->init_text_size,
3037                mod->init_ro_size,
3038                mod->init_size);
3039
3040    do_mod_ctors(mod);
3041    /* Start the module */
3042    if (mod->init != NULL)
3043        ret = do_one_initcall(mod->init);
3044    if (ret < 0) {
3045        /* Init routine failed: abort. Try to protect us from
3046                   buggy refcounters. */
3047        mod->state = MODULE_STATE_GOING;
3048        synchronize_sched();
3049        module_put(mod);
3050        blocking_notifier_call_chain(&module_notify_list,
3051                         MODULE_STATE_GOING, mod);
3052        free_module(mod);
3053        wake_up(&module_wq);
3054        return ret;
3055    }
3056    if (ret > 0) {
3057        printk(KERN_WARNING
3058"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
3059"%s: loading module anyway...\n",
3060               __func__, mod->name, ret,
3061               __func__);
3062        dump_stack();
3063    }
3064
3065    /* Now it's a first class citizen! Wake up anyone waiting for it. */
3066    mod->state = MODULE_STATE_LIVE;
3067    wake_up(&module_wq);
3068    blocking_notifier_call_chain(&module_notify_list,
3069                     MODULE_STATE_LIVE, mod);
3070
3071    /* We need to finish all async code before the module init sequence is done */
3072    async_synchronize_full();
3073
3074    mutex_lock(&module_mutex);
3075    /* Drop initial reference. */
3076    module_put(mod);
3077    trim_init_extable(mod);
3078#ifdef CONFIG_KALLSYMS
3079    mod->num_symtab = mod->core_num_syms;
3080    mod->symtab = mod->core_symtab;
3081    mod->strtab = mod->core_strtab;
3082#endif
3083    unset_module_init_ro_nx(mod);
3084    module_free(mod, mod->module_init);
3085    mod->module_init = NULL;
3086    mod->init_size = 0;
3087    mod->init_ro_size = 0;
3088    mod->init_text_size = 0;
3089    mutex_unlock(&module_mutex);
3090
3091    return 0;
3092}
3093
3094static inline int within(unsigned long addr, void *start, unsigned long size)
3095{
3096    return ((void *)addr >= start && (void *)addr < start + size);
3097}
3098
3099#ifdef CONFIG_KALLSYMS
3100/*
3101 * This ignores the intensely annoying "mapping symbols" found
3102 * in ARM ELF files: $a, $t and $d.
3103 */
3104static inline int is_arm_mapping_symbol(const char *str)
3105{
3106    return str[0] == '$' && strchr("atd", str[1])
3107           && (str[2] == '\0' || str[2] == '.');
3108}
3109
3110static const char *get_ksymbol(struct module *mod,
3111                   unsigned long addr,
3112                   unsigned long *size,
3113                   unsigned long *offset)
3114{
3115    unsigned int i, best = 0;
3116    unsigned long nextval;
3117
3118    /* At worse, next value is at end of module */
3119    if (within_module_init(addr, mod))
3120        nextval = (unsigned long)mod->module_init+mod->init_text_size;
3121    else
3122        nextval = (unsigned long)mod->module_core+mod->core_text_size;
3123
3124    /* Scan for closest preceding symbol, and next symbol. (ELF
3125       starts real symbols at 1). */
3126    for (i = 1; i < mod->num_symtab; i++) {
3127        if (mod->symtab[i].st_shndx == SHN_UNDEF)
3128            continue;
3129
3130        /* We ignore unnamed symbols: they're uninformative
3131         * and inserted at a whim. */
3132        if (mod->symtab[i].st_value <= addr
3133            && mod->symtab[i].st_value > mod->symtab[best].st_value
3134            && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3135            && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3136            best = i;
3137        if (mod->symtab[i].st_value > addr
3138            && mod->symtab[i].st_value < nextval
3139            && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3140            && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3141            nextval = mod->symtab[i].st_value;
3142    }
3143
3144    if (!best)
3145        return NULL;
3146
3147    if (size)
3148        *size = nextval - mod->symtab[best].st_value;
3149    if (offset)
3150        *offset = addr - mod->symtab[best].st_value;
3151    return mod->strtab + mod->symtab[best].st_name;
3152}
3153
3154/* For kallsyms to ask for address resolution. NULL means not found. Careful
3155 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3156const char *module_address_lookup(unsigned long addr,
3157                unsigned long *size,
3158                unsigned long *offset,
3159                char **modname,
3160                char *namebuf)
3161{
3162    struct module *mod;
3163    const char *ret = NULL;
3164
3165    preempt_disable();
3166    list_for_each_entry_rcu(mod, &modules, list) {
3167        if (within_module_init(addr, mod) ||
3168            within_module_core(addr, mod)) {
3169            if (modname)
3170                *modname = mod->name;
3171            ret = get_ksymbol(mod, addr, size, offset);
3172            break;
3173        }
3174    }
3175    /* Make a copy in here where it's safe */
3176    if (ret) {
3177        strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3178        ret = namebuf;
3179    }
3180    preempt_enable();
3181    return ret;
3182}
3183
3184int lookup_module_symbol_name(unsigned long addr, char *symname)
3185{
3186    struct module *mod;
3187
3188    preempt_disable();
3189    list_for_each_entry_rcu(mod, &modules, list) {
3190        if (within_module_init(addr, mod) ||
3191            within_module_core(addr, mod)) {
3192            const char *sym;
3193
3194            sym = get_ksymbol(mod, addr, NULL, NULL);
3195            if (!sym)
3196                goto out;
3197            strlcpy(symname, sym, KSYM_NAME_LEN);
3198            preempt_enable();
3199            return 0;
3200        }
3201    }
3202out:
3203    preempt_enable();
3204    return -ERANGE;
3205}
3206
3207int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3208            unsigned long *offset, char *modname, char *name)
3209{
3210    struct module *mod;
3211
3212    preempt_disable();
3213    list_for_each_entry_rcu(mod, &modules, list) {
3214        if (within_module_init(addr, mod) ||
3215            within_module_core(addr, mod)) {
3216            const char *sym;
3217
3218            sym = get_ksymbol(mod, addr, size, offset);
3219            if (!sym)
3220                goto out;
3221            if (modname)
3222                strlcpy(modname, mod->name, MODULE_NAME_LEN);
3223            if (name)
3224                strlcpy(name, sym, KSYM_NAME_LEN);
3225            preempt_enable();
3226            return 0;
3227        }
3228    }
3229out:
3230    preempt_enable();
3231    return -ERANGE;
3232}
3233
3234int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3235            char *name, char *module_name, int *exported)
3236{
3237    struct module *mod;
3238
3239    preempt_disable();
3240    list_for_each_entry_rcu(mod, &modules, list) {
3241        if (symnum < mod->num_symtab) {
3242            *value = mod->symtab[symnum].st_value;
3243            *type = mod->symtab[symnum].st_info;
3244            strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3245                KSYM_NAME_LEN);
3246            strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3247            *exported = is_exported(name, *value, mod);
3248            preempt_enable();
3249            return 0;
3250        }
3251        symnum -= mod->num_symtab;
3252    }
3253    preempt_enable();
3254    return -ERANGE;
3255}
3256
3257static unsigned long mod_find_symname(struct module *mod, const char *name)
3258{
3259    unsigned int i;
3260
3261    for (i = 0; i < mod->num_symtab; i++)
3262        if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3263            mod->symtab[i].st_info != 'U')
3264            return mod->symtab[i].st_value;
3265    return 0;
3266}
3267
3268/* Look for this name: can be of form module:name. */
3269unsigned long module_kallsyms_lookup_name(const char *name)
3270{
3271    struct module *mod;
3272    char *colon;
3273    unsigned long ret = 0;
3274
3275    /* Don't lock: we're in enough trouble already. */
3276    preempt_disable();
3277    if ((colon = strchr(name, ':')) != NULL) {
3278        *colon = '\0';
3279        if ((mod = find_module(name)) != NULL)
3280            ret = mod_find_symname(mod, colon+1);
3281        *colon = ':';
3282    } else {
3283        list_for_each_entry_rcu(mod, &modules, list)
3284            if ((ret = mod_find_symname(mod, name)) != 0)
3285                break;
3286    }
3287    preempt_enable();
3288    return ret;
3289}
3290
3291int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3292                         struct module *, unsigned long),
3293                   void *data)
3294{
3295    struct module *mod;
3296    unsigned int i;
3297    int ret;
3298
3299    list_for_each_entry(mod, &modules, list) {
3300        for (i = 0; i < mod->num_symtab; i++) {
3301            ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3302                 mod, mod->symtab[i].st_value);
3303            if (ret != 0)
3304                return ret;
3305        }
3306    }
3307    return 0;
3308}
3309#endif /* CONFIG_KALLSYMS */
3310
3311static char *module_flags(struct module *mod, char *buf)
3312{
3313    int bx = 0;
3314
3315    if (mod->taints ||
3316        mod->state == MODULE_STATE_GOING ||
3317        mod->state == MODULE_STATE_COMING) {
3318        buf[bx++] = '(';
3319        bx += module_flags_taint(mod, buf + bx);
3320        /* Show a - for module-is-being-unloaded */
3321        if (mod->state == MODULE_STATE_GOING)
3322            buf[bx++] = '-';
3323        /* Show a + for module-is-being-loaded */
3324        if (mod->state == MODULE_STATE_COMING)
3325            buf[bx++] = '+';
3326        buf[bx++] = ')';
3327    }
3328    buf[bx] = '\0';
3329
3330    return buf;
3331}
3332
3333#ifdef CONFIG_PROC_FS
3334/* Called by the /proc file system to return a list of modules. */
3335static void *m_start(struct seq_file *m, loff_t *pos)
3336{
3337    mutex_lock(&module_mutex);
3338    return seq_list_start(&modules, *pos);
3339}
3340
3341static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3342{
3343    return seq_list_next(p, &modules, pos);
3344}
3345
3346static void m_stop(struct seq_file *m, void *p)
3347{
3348    mutex_unlock(&module_mutex);
3349}
3350
3351static int m_show(struct seq_file *m, void *p)
3352{
3353    struct module *mod = list_entry(p, struct module, list);
3354    char buf[8];
3355
3356    seq_printf(m, "%s %u",
3357           mod->name, mod->init_size + mod->core_size);
3358    print_unload_info(m, mod);
3359
3360    /* Informative for users. */
3361    seq_printf(m, " %s",
3362           mod->state == MODULE_STATE_GOING ? "Unloading":
3363           mod->state == MODULE_STATE_COMING ? "Loading":
3364           "Live");
3365    /* Used by oprofile and other similar tools. */
3366    seq_printf(m, " 0x%pK", mod->module_core);
3367
3368    /* Taints info */
3369    if (mod->taints)
3370        seq_printf(m, " %s", module_flags(mod, buf));
3371
3372    seq_printf(m, "\n");
3373    return 0;
3374}
3375
3376/* Format: modulename size refcount deps address
3377
3378   Where refcount is a number or -, and deps is a comma-separated list
3379   of depends or -.
3380*/
3381static const struct seq_operations modules_op = {
3382    .start = m_start,
3383    .next = m_next,
3384    .stop = m_stop,
3385    .show = m_show
3386};
3387
3388static int modules_open(struct inode *inode, struct file *file)
3389{
3390    return seq_open(file, &modules_op);
3391}
3392
3393static const struct file_operations proc_modules_operations = {
3394    .open = modules_open,
3395    .read = seq_read,
3396    .llseek = seq_lseek,
3397    .release = seq_release,
3398};
3399
3400static int __init proc_modules_init(void)
3401{
3402    proc_create("modules", 0, NULL, &proc_modules_operations);
3403    return 0;
3404}
3405module_init(proc_modules_init);
3406#endif
3407
3408/* Given an address, look for it in the module exception tables. */
3409const struct exception_table_entry *search_module_extables(unsigned long addr)
3410{
3411    const struct exception_table_entry *e = NULL;
3412    struct module *mod;
3413
3414    preempt_disable();
3415    list_for_each_entry_rcu(mod, &modules, list) {
3416        if (mod->num_exentries == 0)
3417            continue;
3418
3419        e = search_extable(mod->extable,
3420                   mod->extable + mod->num_exentries - 1,
3421                   addr);
3422        if (e)
3423            break;
3424    }
3425    preempt_enable();
3426
3427    /* Now, if we found one, we are running inside it now, hence
3428       we cannot unload the module, hence no refcnt needed. */
3429    return e;
3430}
3431
3432/*
3433 * is_module_address - is this address inside a module?
3434 * @addr: the address to check.
3435 *
3436 * See is_module_text_address() if you simply want to see if the address
3437 * is code (not data).
3438 */
3439bool is_module_address(unsigned long addr)
3440{
3441    bool ret;
3442
3443    preempt_disable();
3444    ret = __module_address(addr) != NULL;
3445    preempt_enable();
3446
3447    return ret;
3448}
3449
3450/*
3451 * __module_address - get the module which contains an address.
3452 * @addr: the address.
3453 *
3454 * Must be called with preempt disabled or module mutex held so that
3455 * module doesn't get freed during this.
3456 */
3457struct module *__module_address(unsigned long addr)
3458{
3459    struct module *mod;
3460
3461    if (addr < module_addr_min || addr > module_addr_max)
3462        return NULL;
3463
3464    list_for_each_entry_rcu(mod, &modules, list)
3465        if (within_module_core(addr, mod)
3466            || within_module_init(addr, mod))
3467            return mod;
3468    return NULL;
3469}
3470EXPORT_SYMBOL_GPL(__module_address);
3471
3472/*
3473 * is_module_text_address - is this address inside module code?
3474 * @addr: the address to check.
3475 *
3476 * See is_module_address() if you simply want to see if the address is
3477 * anywhere in a module. See kernel_text_address() for testing if an
3478 * address corresponds to kernel or module code.
3479 */
3480bool is_module_text_address(unsigned long addr)
3481{
3482    bool ret;
3483
3484    preempt_disable();
3485    ret = __module_text_address(addr) != NULL;
3486    preempt_enable();
3487
3488    return ret;
3489}
3490
3491/*
3492 * __module_text_address - get the module whose code contains an address.
3493 * @addr: the address.
3494 *
3495 * Must be called with preempt disabled or module mutex held so that
3496 * module doesn't get freed during this.
3497 */
3498struct module *__module_text_address(unsigned long addr)
3499{
3500    struct module *mod = __module_address(addr);
3501    if (mod) {
3502        /* Make sure it's within the text section. */
3503        if (!within(addr, mod->module_init, mod->init_text_size)
3504            && !within(addr, mod->module_core, mod->core_text_size))
3505            mod = NULL;
3506    }
3507    return mod;
3508}
3509EXPORT_SYMBOL_GPL(__module_text_address);
3510
3511/* Don't grab lock, we're oopsing. */
3512void print_modules(void)
3513{
3514    struct module *mod;
3515    char buf[8];
3516
3517    printk(KERN_DEFAULT "Modules linked in:");
3518    /* Most callers should already have preempt disabled, but make sure */
3519    preempt_disable();
3520    list_for_each_entry_rcu(mod, &modules, list)
3521        printk(" %s%s", mod->name, module_flags(mod, buf));
3522    preempt_enable();
3523    if (last_unloaded_module[0])
3524        printk(" [last unloaded: %s]", last_unloaded_module);
3525    printk("\n");
3526}
3527
3528#ifdef CONFIG_MODVERSIONS
3529/* Generate the signature for all relevant module structures here.
3530 * If these change, we don't want to try to parse the module. */
3531void module_layout(struct module *mod,
3532           struct modversion_info *ver,
3533           struct kernel_param *kp,
3534           struct kernel_symbol *ks,
3535           struct tracepoint * const *tp)
3536{
3537}
3538EXPORT_SYMBOL(module_layout);
3539#endif
3540

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