Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5

Linux/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/trace_events.h>
 22 #include <linux/init.h>
 23 #include <linux/kallsyms.h>
 24 #include <linux/file.h>
 25 #include <linux/fs.h>
 26 #include <linux/sysfs.h>
 27 #include <linux/kernel.h>
 28 #include <linux/slab.h>
 29 #include <linux/vmalloc.h>
 30 #include <linux/elf.h>
 31 #include <linux/proc_fs.h>
 32 #include <linux/security.h>
 33 #include <linux/seq_file.h>
 34 #include <linux/syscalls.h>
 35 #include <linux/fcntl.h>
 36 #include <linux/rcupdate.h>
 37 #include <linux/capability.h>
 38 #include <linux/cpu.h>
 39 #include <linux/moduleparam.h>
 40 #include <linux/errno.h>
 41 #include <linux/err.h>
 42 #include <linux/vermagic.h>
 43 #include <linux/notifier.h>
 44 #include <linux/sched.h>
 45 #include <linux/device.h>
 46 #include <linux/string.h>
 47 #include <linux/mutex.h>
 48 #include <linux/rculist.h>
 49 #include <asm/uaccess.h>
 50 #include <asm/cacheflush.h>
 51 #include <asm/mmu_context.h>
 52 #include <linux/license.h>
 53 #include <asm/sections.h>
 54 #include <linux/tracepoint.h>
 55 #include <linux/ftrace.h>
 56 #include <linux/async.h>
 57 #include <linux/percpu.h>
 58 #include <linux/kmemleak.h>
 59 #include <linux/jump_label.h>
 60 #include <linux/pfn.h>
 61 #include <linux/bsearch.h>
 62 #include <uapi/linux/module.h>
 63 #include "module-internal.h"
 64 
 65 #define CREATE_TRACE_POINTS
 66 #include <trace/events/module.h>
 67 
 68 #ifndef ARCH_SHF_SMALL
 69 #define ARCH_SHF_SMALL 0
 70 #endif
 71 
 72 /*
 73  * Modules' sections will be aligned on page boundaries
 74  * to ensure complete separation of code and data, but
 75  * only when CONFIG_DEBUG_SET_MODULE_RONX=y
 76  */
 77 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 78 # define debug_align(X) ALIGN(X, PAGE_SIZE)
 79 #else
 80 # define debug_align(X) (X)
 81 #endif
 82 
 83 /* If this is set, the section belongs in the init part of the module */
 84 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
 85 
 86 /*
 87  * Mutex protects:
 88  * 1) List of modules (also safely readable with preempt_disable),
 89  * 2) module_use links,
 90  * 3) module_addr_min/module_addr_max.
 91  * (delete and add uses RCU list operations). */
 92 DEFINE_MUTEX(module_mutex);
 93 EXPORT_SYMBOL_GPL(module_mutex);
 94 static LIST_HEAD(modules);
 95 
 96 #ifdef CONFIG_MODULES_TREE_LOOKUP
 97 
 98 /*
 99  * Use a latched RB-tree for __module_address(); this allows us to use
100  * RCU-sched lookups of the address from any context.
101  *
102  * This is conditional on PERF_EVENTS || TRACING because those can really hit
103  * __module_address() hard by doing a lot of stack unwinding; potentially from
104  * NMI context.
105  */
106 
107 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
108 {
109         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
110 
111         return (unsigned long)layout->base;
112 }
113 
114 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
115 {
116         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
117 
118         return (unsigned long)layout->size;
119 }
120 
121 static __always_inline bool
122 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
123 {
124         return __mod_tree_val(a) < __mod_tree_val(b);
125 }
126 
127 static __always_inline int
128 mod_tree_comp(void *key, struct latch_tree_node *n)
129 {
130         unsigned long val = (unsigned long)key;
131         unsigned long start, end;
132 
133         start = __mod_tree_val(n);
134         if (val < start)
135                 return -1;
136 
137         end = start + __mod_tree_size(n);
138         if (val >= end)
139                 return 1;
140 
141         return 0;
142 }
143 
144 static const struct latch_tree_ops mod_tree_ops = {
145         .less = mod_tree_less,
146         .comp = mod_tree_comp,
147 };
148 
149 static struct mod_tree_root {
150         struct latch_tree_root root;
151         unsigned long addr_min;
152         unsigned long addr_max;
153 } mod_tree __cacheline_aligned = {
154         .addr_min = -1UL,
155 };
156 
157 #define module_addr_min mod_tree.addr_min
158 #define module_addr_max mod_tree.addr_max
159 
160 static noinline void __mod_tree_insert(struct mod_tree_node *node)
161 {
162         latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
163 }
164 
165 static void __mod_tree_remove(struct mod_tree_node *node)
166 {
167         latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
168 }
169 
170 /*
171  * These modifications: insert, remove_init and remove; are serialized by the
172  * module_mutex.
173  */
174 static void mod_tree_insert(struct module *mod)
175 {
176         mod->core_layout.mtn.mod = mod;
177         mod->init_layout.mtn.mod = mod;
178 
179         __mod_tree_insert(&mod->core_layout.mtn);
180         if (mod->init_layout.size)
181                 __mod_tree_insert(&mod->init_layout.mtn);
182 }
183 
184 static void mod_tree_remove_init(struct module *mod)
185 {
186         if (mod->init_layout.size)
187                 __mod_tree_remove(&mod->init_layout.mtn);
188 }
189 
190 static void mod_tree_remove(struct module *mod)
191 {
192         __mod_tree_remove(&mod->core_layout.mtn);
193         mod_tree_remove_init(mod);
194 }
195 
196 static struct module *mod_find(unsigned long addr)
197 {
198         struct latch_tree_node *ltn;
199 
200         ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
201         if (!ltn)
202                 return NULL;
203 
204         return container_of(ltn, struct mod_tree_node, node)->mod;
205 }
206 
207 #else /* MODULES_TREE_LOOKUP */
208 
209 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
210 
211 static void mod_tree_insert(struct module *mod) { }
212 static void mod_tree_remove_init(struct module *mod) { }
213 static void mod_tree_remove(struct module *mod) { }
214 
215 static struct module *mod_find(unsigned long addr)
216 {
217         struct module *mod;
218 
219         list_for_each_entry_rcu(mod, &modules, list) {
220                 if (within_module(addr, mod))
221                         return mod;
222         }
223 
224         return NULL;
225 }
226 
227 #endif /* MODULES_TREE_LOOKUP */
228 
229 /*
230  * Bounds of module text, for speeding up __module_address.
231  * Protected by module_mutex.
232  */
233 static void __mod_update_bounds(void *base, unsigned int size)
234 {
235         unsigned long min = (unsigned long)base;
236         unsigned long max = min + size;
237 
238         if (min < module_addr_min)
239                 module_addr_min = min;
240         if (max > module_addr_max)
241                 module_addr_max = max;
242 }
243 
244 static void mod_update_bounds(struct module *mod)
245 {
246         __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
247         if (mod->init_layout.size)
248                 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
249 }
250 
251 #ifdef CONFIG_KGDB_KDB
252 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
253 #endif /* CONFIG_KGDB_KDB */
254 
255 static void module_assert_mutex(void)
256 {
257         lockdep_assert_held(&module_mutex);
258 }
259 
260 static void module_assert_mutex_or_preempt(void)
261 {
262 #ifdef CONFIG_LOCKDEP
263         if (unlikely(!debug_locks))
264                 return;
265 
266         WARN_ON(!rcu_read_lock_sched_held() &&
267                 !lockdep_is_held(&module_mutex));
268 #endif
269 }
270 
271 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
272 #ifndef CONFIG_MODULE_SIG_FORCE
273 module_param(sig_enforce, bool_enable_only, 0644);
274 #endif /* !CONFIG_MODULE_SIG_FORCE */
275 
276 /* Block module loading/unloading? */
277 int modules_disabled = 0;
278 core_param(nomodule, modules_disabled, bint, 0);
279 
280 /* Waiting for a module to finish initializing? */
281 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
282 
283 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
284 
285 int register_module_notifier(struct notifier_block *nb)
286 {
287         return blocking_notifier_chain_register(&module_notify_list, nb);
288 }
289 EXPORT_SYMBOL(register_module_notifier);
290 
291 int unregister_module_notifier(struct notifier_block *nb)
292 {
293         return blocking_notifier_chain_unregister(&module_notify_list, nb);
294 }
295 EXPORT_SYMBOL(unregister_module_notifier);
296 
297 struct load_info {
298         Elf_Ehdr *hdr;
299         unsigned long len;
300         Elf_Shdr *sechdrs;
301         char *secstrings, *strtab;
302         unsigned long symoffs, stroffs;
303         struct _ddebug *debug;
304         unsigned int num_debug;
305         bool sig_ok;
306 #ifdef CONFIG_KALLSYMS
307         unsigned long mod_kallsyms_init_off;
308 #endif
309         struct {
310                 unsigned int sym, str, mod, vers, info, pcpu;
311         } index;
312 };
313 
314 /* We require a truly strong try_module_get(): 0 means failure due to
315    ongoing or failed initialization etc. */
316 static inline int strong_try_module_get(struct module *mod)
317 {
318         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
319         if (mod && mod->state == MODULE_STATE_COMING)
320                 return -EBUSY;
321         if (try_module_get(mod))
322                 return 0;
323         else
324                 return -ENOENT;
325 }
326 
327 static inline void add_taint_module(struct module *mod, unsigned flag,
328                                     enum lockdep_ok lockdep_ok)
329 {
330         add_taint(flag, lockdep_ok);
331         mod->taints |= (1U << flag);
332 }
333 
334 /*
335  * A thread that wants to hold a reference to a module only while it
336  * is running can call this to safely exit.  nfsd and lockd use this.
337  */
338 void __module_put_and_exit(struct module *mod, long code)
339 {
340         module_put(mod);
341         do_exit(code);
342 }
343 EXPORT_SYMBOL(__module_put_and_exit);
344 
345 /* Find a module section: 0 means not found. */
346 static unsigned int find_sec(const struct load_info *info, const char *name)
347 {
348         unsigned int i;
349 
350         for (i = 1; i < info->hdr->e_shnum; i++) {
351                 Elf_Shdr *shdr = &info->sechdrs[i];
352                 /* Alloc bit cleared means "ignore it." */
353                 if ((shdr->sh_flags & SHF_ALLOC)
354                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
355                         return i;
356         }
357         return 0;
358 }
359 
360 /* Find a module section, or NULL. */
361 static void *section_addr(const struct load_info *info, const char *name)
362 {
363         /* Section 0 has sh_addr 0. */
364         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
365 }
366 
367 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
368 static void *section_objs(const struct load_info *info,
369                           const char *name,
370                           size_t object_size,
371                           unsigned int *num)
372 {
373         unsigned int sec = find_sec(info, name);
374 
375         /* Section 0 has sh_addr 0 and sh_size 0. */
376         *num = info->sechdrs[sec].sh_size / object_size;
377         return (void *)info->sechdrs[sec].sh_addr;
378 }
379 
380 /* Provided by the linker */
381 extern const struct kernel_symbol __start___ksymtab[];
382 extern const struct kernel_symbol __stop___ksymtab[];
383 extern const struct kernel_symbol __start___ksymtab_gpl[];
384 extern const struct kernel_symbol __stop___ksymtab_gpl[];
385 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
386 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
387 extern const unsigned long __start___kcrctab[];
388 extern const unsigned long __start___kcrctab_gpl[];
389 extern const unsigned long __start___kcrctab_gpl_future[];
390 #ifdef CONFIG_UNUSED_SYMBOLS
391 extern const struct kernel_symbol __start___ksymtab_unused[];
392 extern const struct kernel_symbol __stop___ksymtab_unused[];
393 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
394 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
395 extern const unsigned long __start___kcrctab_unused[];
396 extern const unsigned long __start___kcrctab_unused_gpl[];
397 #endif
398 
399 #ifndef CONFIG_MODVERSIONS
400 #define symversion(base, idx) NULL
401 #else
402 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
403 #endif
404 
405 static bool each_symbol_in_section(const struct symsearch *arr,
406                                    unsigned int arrsize,
407                                    struct module *owner,
408                                    bool (*fn)(const struct symsearch *syms,
409                                               struct module *owner,
410                                               void *data),
411                                    void *data)
412 {
413         unsigned int j;
414 
415         for (j = 0; j < arrsize; j++) {
416                 if (fn(&arr[j], owner, data))
417                         return true;
418         }
419 
420         return false;
421 }
422 
423 /* Returns true as soon as fn returns true, otherwise false. */
424 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
425                                     struct module *owner,
426                                     void *data),
427                          void *data)
428 {
429         struct module *mod;
430         static const struct symsearch arr[] = {
431                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
432                   NOT_GPL_ONLY, false },
433                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
434                   __start___kcrctab_gpl,
435                   GPL_ONLY, false },
436                 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
437                   __start___kcrctab_gpl_future,
438                   WILL_BE_GPL_ONLY, false },
439 #ifdef CONFIG_UNUSED_SYMBOLS
440                 { __start___ksymtab_unused, __stop___ksymtab_unused,
441                   __start___kcrctab_unused,
442                   NOT_GPL_ONLY, true },
443                 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
444                   __start___kcrctab_unused_gpl,
445                   GPL_ONLY, true },
446 #endif
447         };
448 
449         module_assert_mutex_or_preempt();
450 
451         if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
452                 return true;
453 
454         list_for_each_entry_rcu(mod, &modules, list) {
455                 struct symsearch arr[] = {
456                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
457                           NOT_GPL_ONLY, false },
458                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
459                           mod->gpl_crcs,
460                           GPL_ONLY, false },
461                         { mod->gpl_future_syms,
462                           mod->gpl_future_syms + mod->num_gpl_future_syms,
463                           mod->gpl_future_crcs,
464                           WILL_BE_GPL_ONLY, false },
465 #ifdef CONFIG_UNUSED_SYMBOLS
466                         { mod->unused_syms,
467                           mod->unused_syms + mod->num_unused_syms,
468                           mod->unused_crcs,
469                           NOT_GPL_ONLY, true },
470                         { mod->unused_gpl_syms,
471                           mod->unused_gpl_syms + mod->num_unused_gpl_syms,
472                           mod->unused_gpl_crcs,
473                           GPL_ONLY, true },
474 #endif
475                 };
476 
477                 if (mod->state == MODULE_STATE_UNFORMED)
478                         continue;
479 
480                 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
481                         return true;
482         }
483         return false;
484 }
485 EXPORT_SYMBOL_GPL(each_symbol_section);
486 
487 struct find_symbol_arg {
488         /* Input */
489         const char *name;
490         bool gplok;
491         bool warn;
492 
493         /* Output */
494         struct module *owner;
495         const unsigned long *crc;
496         const struct kernel_symbol *sym;
497 };
498 
499 static bool check_symbol(const struct symsearch *syms,
500                                  struct module *owner,
501                                  unsigned int symnum, void *data)
502 {
503         struct find_symbol_arg *fsa = data;
504 
505         if (!fsa->gplok) {
506                 if (syms->licence == GPL_ONLY)
507                         return false;
508                 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
509                         pr_warn("Symbol %s is being used by a non-GPL module, "
510                                 "which will not be allowed in the future\n",
511                                 fsa->name);
512                 }
513         }
514 
515 #ifdef CONFIG_UNUSED_SYMBOLS
516         if (syms->unused && fsa->warn) {
517                 pr_warn("Symbol %s is marked as UNUSED, however this module is "
518                         "using it.\n", fsa->name);
519                 pr_warn("This symbol will go away in the future.\n");
520                 pr_warn("Please evaluate if this is the right api to use and "
521                         "if it really is, submit a report to the linux kernel "
522                         "mailing list together with submitting your code for "
523                         "inclusion.\n");
524         }
525 #endif
526 
527         fsa->owner = owner;
528         fsa->crc = symversion(syms->crcs, symnum);
529         fsa->sym = &syms->start[symnum];
530         return true;
531 }
532 
533 static int cmp_name(const void *va, const void *vb)
534 {
535         const char *a;
536         const struct kernel_symbol *b;
537         a = va; b = vb;
538         return strcmp(a, b->name);
539 }
540 
541 static bool find_symbol_in_section(const struct symsearch *syms,
542                                    struct module *owner,
543                                    void *data)
544 {
545         struct find_symbol_arg *fsa = data;
546         struct kernel_symbol *sym;
547 
548         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
549                         sizeof(struct kernel_symbol), cmp_name);
550 
551         if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
552                 return true;
553 
554         return false;
555 }
556 
557 /* Find a symbol and return it, along with, (optional) crc and
558  * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
559 const struct kernel_symbol *find_symbol(const char *name,
560                                         struct module **owner,
561                                         const unsigned long **crc,
562                                         bool gplok,
563                                         bool warn)
564 {
565         struct find_symbol_arg fsa;
566 
567         fsa.name = name;
568         fsa.gplok = gplok;
569         fsa.warn = warn;
570 
571         if (each_symbol_section(find_symbol_in_section, &fsa)) {
572                 if (owner)
573                         *owner = fsa.owner;
574                 if (crc)
575                         *crc = fsa.crc;
576                 return fsa.sym;
577         }
578 
579         pr_debug("Failed to find symbol %s\n", name);
580         return NULL;
581 }
582 EXPORT_SYMBOL_GPL(find_symbol);
583 
584 /*
585  * Search for module by name: must hold module_mutex (or preempt disabled
586  * for read-only access).
587  */
588 static struct module *find_module_all(const char *name, size_t len,
589                                       bool even_unformed)
590 {
591         struct module *mod;
592 
593         module_assert_mutex_or_preempt();
594 
595         list_for_each_entry(mod, &modules, list) {
596                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
597                         continue;
598                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
599                         return mod;
600         }
601         return NULL;
602 }
603 
604 struct module *find_module(const char *name)
605 {
606         module_assert_mutex();
607         return find_module_all(name, strlen(name), false);
608 }
609 EXPORT_SYMBOL_GPL(find_module);
610 
611 #ifdef CONFIG_SMP
612 
613 static inline void __percpu *mod_percpu(struct module *mod)
614 {
615         return mod->percpu;
616 }
617 
618 static int percpu_modalloc(struct module *mod, struct load_info *info)
619 {
620         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
621         unsigned long align = pcpusec->sh_addralign;
622 
623         if (!pcpusec->sh_size)
624                 return 0;
625 
626         if (align > PAGE_SIZE) {
627                 pr_warn("%s: per-cpu alignment %li > %li\n",
628                         mod->name, align, PAGE_SIZE);
629                 align = PAGE_SIZE;
630         }
631 
632         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
633         if (!mod->percpu) {
634                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
635                         mod->name, (unsigned long)pcpusec->sh_size);
636                 return -ENOMEM;
637         }
638         mod->percpu_size = pcpusec->sh_size;
639         return 0;
640 }
641 
642 static void percpu_modfree(struct module *mod)
643 {
644         free_percpu(mod->percpu);
645 }
646 
647 static unsigned int find_pcpusec(struct load_info *info)
648 {
649         return find_sec(info, ".data..percpu");
650 }
651 
652 static void percpu_modcopy(struct module *mod,
653                            const void *from, unsigned long size)
654 {
655         int cpu;
656 
657         for_each_possible_cpu(cpu)
658                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
659 }
660 
661 /**
662  * is_module_percpu_address - test whether address is from module static percpu
663  * @addr: address to test
664  *
665  * Test whether @addr belongs to module static percpu area.
666  *
667  * RETURNS:
668  * %true if @addr is from module static percpu area
669  */
670 bool is_module_percpu_address(unsigned long addr)
671 {
672         struct module *mod;
673         unsigned int cpu;
674 
675         preempt_disable();
676 
677         list_for_each_entry_rcu(mod, &modules, list) {
678                 if (mod->state == MODULE_STATE_UNFORMED)
679                         continue;
680                 if (!mod->percpu_size)
681                         continue;
682                 for_each_possible_cpu(cpu) {
683                         void *start = per_cpu_ptr(mod->percpu, cpu);
684 
685                         if ((void *)addr >= start &&
686                             (void *)addr < start + mod->percpu_size) {
687                                 preempt_enable();
688                                 return true;
689                         }
690                 }
691         }
692 
693         preempt_enable();
694         return false;
695 }
696 
697 #else /* ... !CONFIG_SMP */
698 
699 static inline void __percpu *mod_percpu(struct module *mod)
700 {
701         return NULL;
702 }
703 static int percpu_modalloc(struct module *mod, struct load_info *info)
704 {
705         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
706         if (info->sechdrs[info->index.pcpu].sh_size != 0)
707                 return -ENOMEM;
708         return 0;
709 }
710 static inline void percpu_modfree(struct module *mod)
711 {
712 }
713 static unsigned int find_pcpusec(struct load_info *info)
714 {
715         return 0;
716 }
717 static inline void percpu_modcopy(struct module *mod,
718                                   const void *from, unsigned long size)
719 {
720         /* pcpusec should be 0, and size of that section should be 0. */
721         BUG_ON(size != 0);
722 }
723 bool is_module_percpu_address(unsigned long addr)
724 {
725         return false;
726 }
727 
728 #endif /* CONFIG_SMP */
729 
730 #define MODINFO_ATTR(field)     \
731 static void setup_modinfo_##field(struct module *mod, const char *s)  \
732 {                                                                     \
733         mod->field = kstrdup(s, GFP_KERNEL);                          \
734 }                                                                     \
735 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
736                         struct module_kobject *mk, char *buffer)      \
737 {                                                                     \
738         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
739 }                                                                     \
740 static int modinfo_##field##_exists(struct module *mod)               \
741 {                                                                     \
742         return mod->field != NULL;                                    \
743 }                                                                     \
744 static void free_modinfo_##field(struct module *mod)                  \
745 {                                                                     \
746         kfree(mod->field);                                            \
747         mod->field = NULL;                                            \
748 }                                                                     \
749 static struct module_attribute modinfo_##field = {                    \
750         .attr = { .name = __stringify(field), .mode = 0444 },         \
751         .show = show_modinfo_##field,                                 \
752         .setup = setup_modinfo_##field,                               \
753         .test = modinfo_##field##_exists,                             \
754         .free = free_modinfo_##field,                                 \
755 };
756 
757 MODINFO_ATTR(version);
758 MODINFO_ATTR(srcversion);
759 
760 static char last_unloaded_module[MODULE_NAME_LEN+1];
761 
762 #ifdef CONFIG_MODULE_UNLOAD
763 
764 EXPORT_TRACEPOINT_SYMBOL(module_get);
765 
766 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
767 #define MODULE_REF_BASE 1
768 
769 /* Init the unload section of the module. */
770 static int module_unload_init(struct module *mod)
771 {
772         /*
773          * Initialize reference counter to MODULE_REF_BASE.
774          * refcnt == 0 means module is going.
775          */
776         atomic_set(&mod->refcnt, MODULE_REF_BASE);
777 
778         INIT_LIST_HEAD(&mod->source_list);
779         INIT_LIST_HEAD(&mod->target_list);
780 
781         /* Hold reference count during initialization. */
782         atomic_inc(&mod->refcnt);
783 
784         return 0;
785 }
786 
787 /* Does a already use b? */
788 static int already_uses(struct module *a, struct module *b)
789 {
790         struct module_use *use;
791 
792         list_for_each_entry(use, &b->source_list, source_list) {
793                 if (use->source == a) {
794                         pr_debug("%s uses %s!\n", a->name, b->name);
795                         return 1;
796                 }
797         }
798         pr_debug("%s does not use %s!\n", a->name, b->name);
799         return 0;
800 }
801 
802 /*
803  * Module a uses b
804  *  - we add 'a' as a "source", 'b' as a "target" of module use
805  *  - the module_use is added to the list of 'b' sources (so
806  *    'b' can walk the list to see who sourced them), and of 'a'
807  *    targets (so 'a' can see what modules it targets).
808  */
809 static int add_module_usage(struct module *a, struct module *b)
810 {
811         struct module_use *use;
812 
813         pr_debug("Allocating new usage for %s.\n", a->name);
814         use = kmalloc(sizeof(*use), GFP_ATOMIC);
815         if (!use) {
816                 pr_warn("%s: out of memory loading\n", a->name);
817                 return -ENOMEM;
818         }
819 
820         use->source = a;
821         use->target = b;
822         list_add(&use->source_list, &b->source_list);
823         list_add(&use->target_list, &a->target_list);
824         return 0;
825 }
826 
827 /* Module a uses b: caller needs module_mutex() */
828 int ref_module(struct module *a, struct module *b)
829 {
830         int err;
831 
832         if (b == NULL || already_uses(a, b))
833                 return 0;
834 
835         /* If module isn't available, we fail. */
836         err = strong_try_module_get(b);
837         if (err)
838                 return err;
839 
840         err = add_module_usage(a, b);
841         if (err) {
842                 module_put(b);
843                 return err;
844         }
845         return 0;
846 }
847 EXPORT_SYMBOL_GPL(ref_module);
848 
849 /* Clear the unload stuff of the module. */
850 static void module_unload_free(struct module *mod)
851 {
852         struct module_use *use, *tmp;
853 
854         mutex_lock(&module_mutex);
855         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
856                 struct module *i = use->target;
857                 pr_debug("%s unusing %s\n", mod->name, i->name);
858                 module_put(i);
859                 list_del(&use->source_list);
860                 list_del(&use->target_list);
861                 kfree(use);
862         }
863         mutex_unlock(&module_mutex);
864 }
865 
866 #ifdef CONFIG_MODULE_FORCE_UNLOAD
867 static inline int try_force_unload(unsigned int flags)
868 {
869         int ret = (flags & O_TRUNC);
870         if (ret)
871                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
872         return ret;
873 }
874 #else
875 static inline int try_force_unload(unsigned int flags)
876 {
877         return 0;
878 }
879 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
880 
881 /* Try to release refcount of module, 0 means success. */
882 static int try_release_module_ref(struct module *mod)
883 {
884         int ret;
885 
886         /* Try to decrement refcnt which we set at loading */
887         ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
888         BUG_ON(ret < 0);
889         if (ret)
890                 /* Someone can put this right now, recover with checking */
891                 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
892 
893         return ret;
894 }
895 
896 static int try_stop_module(struct module *mod, int flags, int *forced)
897 {
898         /* If it's not unused, quit unless we're forcing. */
899         if (try_release_module_ref(mod) != 0) {
900                 *forced = try_force_unload(flags);
901                 if (!(*forced))
902                         return -EWOULDBLOCK;
903         }
904 
905         /* Mark it as dying. */
906         mod->state = MODULE_STATE_GOING;
907 
908         return 0;
909 }
910 
911 /**
912  * module_refcount - return the refcount or -1 if unloading
913  *
914  * @mod:        the module we're checking
915  *
916  * Returns:
917  *      -1 if the module is in the process of unloading
918  *      otherwise the number of references in the kernel to the module
919  */
920 int module_refcount(struct module *mod)
921 {
922         return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
923 }
924 EXPORT_SYMBOL(module_refcount);
925 
926 /* This exists whether we can unload or not */
927 static void free_module(struct module *mod);
928 
929 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
930                 unsigned int, flags)
931 {
932         struct module *mod;
933         char name[MODULE_NAME_LEN];
934         int ret, forced = 0;
935 
936         if (!capable(CAP_SYS_MODULE) || modules_disabled)
937                 return -EPERM;
938 
939         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
940                 return -EFAULT;
941         name[MODULE_NAME_LEN-1] = '\0';
942 
943         if (mutex_lock_interruptible(&module_mutex) != 0)
944                 return -EINTR;
945 
946         mod = find_module(name);
947         if (!mod) {
948                 ret = -ENOENT;
949                 goto out;
950         }
951 
952         if (!list_empty(&mod->source_list)) {
953                 /* Other modules depend on us: get rid of them first. */
954                 ret = -EWOULDBLOCK;
955                 goto out;
956         }
957 
958         /* Doing init or already dying? */
959         if (mod->state != MODULE_STATE_LIVE) {
960                 /* FIXME: if (force), slam module count damn the torpedoes */
961                 pr_debug("%s already dying\n", mod->name);
962                 ret = -EBUSY;
963                 goto out;
964         }
965 
966         /* If it has an init func, it must have an exit func to unload */
967         if (mod->init && !mod->exit) {
968                 forced = try_force_unload(flags);
969                 if (!forced) {
970                         /* This module can't be removed */
971                         ret = -EBUSY;
972                         goto out;
973                 }
974         }
975 
976         /* Stop the machine so refcounts can't move and disable module. */
977         ret = try_stop_module(mod, flags, &forced);
978         if (ret != 0)
979                 goto out;
980 
981         mutex_unlock(&module_mutex);
982         /* Final destruction now no one is using it. */
983         if (mod->exit != NULL)
984                 mod->exit();
985         blocking_notifier_call_chain(&module_notify_list,
986                                      MODULE_STATE_GOING, mod);
987         ftrace_release_mod(mod);
988 
989         async_synchronize_full();
990 
991         /* Store the name of the last unloaded module for diagnostic purposes */
992         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
993 
994         free_module(mod);
995         return 0;
996 out:
997         mutex_unlock(&module_mutex);
998         return ret;
999 }
1000 
1001 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1002 {
1003         struct module_use *use;
1004         int printed_something = 0;
1005 
1006         seq_printf(m, " %i ", module_refcount(mod));
1007 
1008         /*
1009          * Always include a trailing , so userspace can differentiate
1010          * between this and the old multi-field proc format.
1011          */
1012         list_for_each_entry(use, &mod->source_list, source_list) {
1013                 printed_something = 1;
1014                 seq_printf(m, "%s,", use->source->name);
1015         }
1016 
1017         if (mod->init != NULL && mod->exit == NULL) {
1018                 printed_something = 1;
1019                 seq_puts(m, "[permanent],");
1020         }
1021 
1022         if (!printed_something)
1023                 seq_puts(m, "-");
1024 }
1025 
1026 void __symbol_put(const char *symbol)
1027 {
1028         struct module *owner;
1029 
1030         preempt_disable();
1031         if (!find_symbol(symbol, &owner, NULL, true, false))
1032                 BUG();
1033         module_put(owner);
1034         preempt_enable();
1035 }
1036 EXPORT_SYMBOL(__symbol_put);
1037 
1038 /* Note this assumes addr is a function, which it currently always is. */
1039 void symbol_put_addr(void *addr)
1040 {
1041         struct module *modaddr;
1042         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1043 
1044         if (core_kernel_text(a))
1045                 return;
1046 
1047         /*
1048          * Even though we hold a reference on the module; we still need to
1049          * disable preemption in order to safely traverse the data structure.
1050          */
1051         preempt_disable();
1052         modaddr = __module_text_address(a);
1053         BUG_ON(!modaddr);
1054         module_put(modaddr);
1055         preempt_enable();
1056 }
1057 EXPORT_SYMBOL_GPL(symbol_put_addr);
1058 
1059 static ssize_t show_refcnt(struct module_attribute *mattr,
1060                            struct module_kobject *mk, char *buffer)
1061 {
1062         return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1063 }
1064 
1065 static struct module_attribute modinfo_refcnt =
1066         __ATTR(refcnt, 0444, show_refcnt, NULL);
1067 
1068 void __module_get(struct module *module)
1069 {
1070         if (module) {
1071                 preempt_disable();
1072                 atomic_inc(&module->refcnt);
1073                 trace_module_get(module, _RET_IP_);
1074                 preempt_enable();
1075         }
1076 }
1077 EXPORT_SYMBOL(__module_get);
1078 
1079 bool try_module_get(struct module *module)
1080 {
1081         bool ret = true;
1082 
1083         if (module) {
1084                 preempt_disable();
1085                 /* Note: here, we can fail to get a reference */
1086                 if (likely(module_is_live(module) &&
1087                            atomic_inc_not_zero(&module->refcnt) != 0))
1088                         trace_module_get(module, _RET_IP_);
1089                 else
1090                         ret = false;
1091 
1092                 preempt_enable();
1093         }
1094         return ret;
1095 }
1096 EXPORT_SYMBOL(try_module_get);
1097 
1098 void module_put(struct module *module)
1099 {
1100         int ret;
1101 
1102         if (module) {
1103                 preempt_disable();
1104                 ret = atomic_dec_if_positive(&module->refcnt);
1105                 WARN_ON(ret < 0);       /* Failed to put refcount */
1106                 trace_module_put(module, _RET_IP_);
1107                 preempt_enable();
1108         }
1109 }
1110 EXPORT_SYMBOL(module_put);
1111 
1112 #else /* !CONFIG_MODULE_UNLOAD */
1113 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1114 {
1115         /* We don't know the usage count, or what modules are using. */
1116         seq_puts(m, " - -");
1117 }
1118 
1119 static inline void module_unload_free(struct module *mod)
1120 {
1121 }
1122 
1123 int ref_module(struct module *a, struct module *b)
1124 {
1125         return strong_try_module_get(b);
1126 }
1127 EXPORT_SYMBOL_GPL(ref_module);
1128 
1129 static inline int module_unload_init(struct module *mod)
1130 {
1131         return 0;
1132 }
1133 #endif /* CONFIG_MODULE_UNLOAD */
1134 
1135 static size_t module_flags_taint(struct module *mod, char *buf)
1136 {
1137         size_t l = 0;
1138 
1139         if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1140                 buf[l++] = 'P';
1141         if (mod->taints & (1 << TAINT_OOT_MODULE))
1142                 buf[l++] = 'O';
1143         if (mod->taints & (1 << TAINT_FORCED_MODULE))
1144                 buf[l++] = 'F';
1145         if (mod->taints & (1 << TAINT_CRAP))
1146                 buf[l++] = 'C';
1147         if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1148                 buf[l++] = 'E';
1149         /*
1150          * TAINT_FORCED_RMMOD: could be added.
1151          * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1152          * apply to modules.
1153          */
1154         return l;
1155 }
1156 
1157 static ssize_t show_initstate(struct module_attribute *mattr,
1158                               struct module_kobject *mk, char *buffer)
1159 {
1160         const char *state = "unknown";
1161 
1162         switch (mk->mod->state) {
1163         case MODULE_STATE_LIVE:
1164                 state = "live";
1165                 break;
1166         case MODULE_STATE_COMING:
1167                 state = "coming";
1168                 break;
1169         case MODULE_STATE_GOING:
1170                 state = "going";
1171                 break;
1172         default:
1173                 BUG();
1174         }
1175         return sprintf(buffer, "%s\n", state);
1176 }
1177 
1178 static struct module_attribute modinfo_initstate =
1179         __ATTR(initstate, 0444, show_initstate, NULL);
1180 
1181 static ssize_t store_uevent(struct module_attribute *mattr,
1182                             struct module_kobject *mk,
1183                             const char *buffer, size_t count)
1184 {
1185         enum kobject_action action;
1186 
1187         if (kobject_action_type(buffer, count, &action) == 0)
1188                 kobject_uevent(&mk->kobj, action);
1189         return count;
1190 }
1191 
1192 struct module_attribute module_uevent =
1193         __ATTR(uevent, 0200, NULL, store_uevent);
1194 
1195 static ssize_t show_coresize(struct module_attribute *mattr,
1196                              struct module_kobject *mk, char *buffer)
1197 {
1198         return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1199 }
1200 
1201 static struct module_attribute modinfo_coresize =
1202         __ATTR(coresize, 0444, show_coresize, NULL);
1203 
1204 static ssize_t show_initsize(struct module_attribute *mattr,
1205                              struct module_kobject *mk, char *buffer)
1206 {
1207         return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1208 }
1209 
1210 static struct module_attribute modinfo_initsize =
1211         __ATTR(initsize, 0444, show_initsize, NULL);
1212 
1213 static ssize_t show_taint(struct module_attribute *mattr,
1214                           struct module_kobject *mk, char *buffer)
1215 {
1216         size_t l;
1217 
1218         l = module_flags_taint(mk->mod, buffer);
1219         buffer[l++] = '\n';
1220         return l;
1221 }
1222 
1223 static struct module_attribute modinfo_taint =
1224         __ATTR(taint, 0444, show_taint, NULL);
1225 
1226 static struct module_attribute *modinfo_attrs[] = {
1227         &module_uevent,
1228         &modinfo_version,
1229         &modinfo_srcversion,
1230         &modinfo_initstate,
1231         &modinfo_coresize,
1232         &modinfo_initsize,
1233         &modinfo_taint,
1234 #ifdef CONFIG_MODULE_UNLOAD
1235         &modinfo_refcnt,
1236 #endif
1237         NULL,
1238 };
1239 
1240 static const char vermagic[] = VERMAGIC_STRING;
1241 
1242 static int try_to_force_load(struct module *mod, const char *reason)
1243 {
1244 #ifdef CONFIG_MODULE_FORCE_LOAD
1245         if (!test_taint(TAINT_FORCED_MODULE))
1246                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1247         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1248         return 0;
1249 #else
1250         return -ENOEXEC;
1251 #endif
1252 }
1253 
1254 #ifdef CONFIG_MODVERSIONS
1255 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1256 static unsigned long maybe_relocated(unsigned long crc,
1257                                      const struct module *crc_owner)
1258 {
1259 #ifdef ARCH_RELOCATES_KCRCTAB
1260         if (crc_owner == NULL)
1261                 return crc - (unsigned long)reloc_start;
1262 #endif
1263         return crc;
1264 }
1265 
1266 static int check_version(Elf_Shdr *sechdrs,
1267                          unsigned int versindex,
1268                          const char *symname,
1269                          struct module *mod,
1270                          const unsigned long *crc,
1271                          const struct module *crc_owner)
1272 {
1273         unsigned int i, num_versions;
1274         struct modversion_info *versions;
1275 
1276         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1277         if (!crc)
1278                 return 1;
1279 
1280         /* No versions at all?  modprobe --force does this. */
1281         if (versindex == 0)
1282                 return try_to_force_load(mod, symname) == 0;
1283 
1284         versions = (void *) sechdrs[versindex].sh_addr;
1285         num_versions = sechdrs[versindex].sh_size
1286                 / sizeof(struct modversion_info);
1287 
1288         for (i = 0; i < num_versions; i++) {
1289                 if (strcmp(versions[i].name, symname) != 0)
1290                         continue;
1291 
1292                 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1293                         return 1;
1294                 pr_debug("Found checksum %lX vs module %lX\n",
1295                        maybe_relocated(*crc, crc_owner), versions[i].crc);
1296                 goto bad_version;
1297         }
1298 
1299         pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1300         return 0;
1301 
1302 bad_version:
1303         pr_warn("%s: disagrees about version of symbol %s\n",
1304                mod->name, symname);
1305         return 0;
1306 }
1307 
1308 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1309                                           unsigned int versindex,
1310                                           struct module *mod)
1311 {
1312         const unsigned long *crc;
1313 
1314         /*
1315          * Since this should be found in kernel (which can't be removed), no
1316          * locking is necessary -- use preempt_disable() to placate lockdep.
1317          */
1318         preempt_disable();
1319         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1320                          &crc, true, false)) {
1321                 preempt_enable();
1322                 BUG();
1323         }
1324         preempt_enable();
1325         return check_version(sechdrs, versindex,
1326                              VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1327                              NULL);
1328 }
1329 
1330 /* First part is kernel version, which we ignore if module has crcs. */
1331 static inline int same_magic(const char *amagic, const char *bmagic,
1332                              bool has_crcs)
1333 {
1334         if (has_crcs) {
1335                 amagic += strcspn(amagic, " ");
1336                 bmagic += strcspn(bmagic, " ");
1337         }
1338         return strcmp(amagic, bmagic) == 0;
1339 }
1340 #else
1341 static inline int check_version(Elf_Shdr *sechdrs,
1342                                 unsigned int versindex,
1343                                 const char *symname,
1344                                 struct module *mod,
1345                                 const unsigned long *crc,
1346                                 const struct module *crc_owner)
1347 {
1348         return 1;
1349 }
1350 
1351 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1352                                           unsigned int versindex,
1353                                           struct module *mod)
1354 {
1355         return 1;
1356 }
1357 
1358 static inline int same_magic(const char *amagic, const char *bmagic,
1359                              bool has_crcs)
1360 {
1361         return strcmp(amagic, bmagic) == 0;
1362 }
1363 #endif /* CONFIG_MODVERSIONS */
1364 
1365 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1366 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1367                                                   const struct load_info *info,
1368                                                   const char *name,
1369                                                   char ownername[])
1370 {
1371         struct module *owner;
1372         const struct kernel_symbol *sym;
1373         const unsigned long *crc;
1374         int err;
1375 
1376         /*
1377          * The module_mutex should not be a heavily contended lock;
1378          * if we get the occasional sleep here, we'll go an extra iteration
1379          * in the wait_event_interruptible(), which is harmless.
1380          */
1381         sched_annotate_sleep();
1382         mutex_lock(&module_mutex);
1383         sym = find_symbol(name, &owner, &crc,
1384                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1385         if (!sym)
1386                 goto unlock;
1387 
1388         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1389                            owner)) {
1390                 sym = ERR_PTR(-EINVAL);
1391                 goto getname;
1392         }
1393 
1394         err = ref_module(mod, owner);
1395         if (err) {
1396                 sym = ERR_PTR(err);
1397                 goto getname;
1398         }
1399 
1400 getname:
1401         /* We must make copy under the lock if we failed to get ref. */
1402         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1403 unlock:
1404         mutex_unlock(&module_mutex);
1405         return sym;
1406 }
1407 
1408 static const struct kernel_symbol *
1409 resolve_symbol_wait(struct module *mod,
1410                     const struct load_info *info,
1411                     const char *name)
1412 {
1413         const struct kernel_symbol *ksym;
1414         char owner[MODULE_NAME_LEN];
1415 
1416         if (wait_event_interruptible_timeout(module_wq,
1417                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1418                         || PTR_ERR(ksym) != -EBUSY,
1419                                              30 * HZ) <= 0) {
1420                 pr_warn("%s: gave up waiting for init of module %s.\n",
1421                         mod->name, owner);
1422         }
1423         return ksym;
1424 }
1425 
1426 /*
1427  * /sys/module/foo/sections stuff
1428  * J. Corbet <corbet@lwn.net>
1429  */
1430 #ifdef CONFIG_SYSFS
1431 
1432 #ifdef CONFIG_KALLSYMS
1433 static inline bool sect_empty(const Elf_Shdr *sect)
1434 {
1435         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1436 }
1437 
1438 struct module_sect_attr {
1439         struct module_attribute mattr;
1440         char *name;
1441         unsigned long address;
1442 };
1443 
1444 struct module_sect_attrs {
1445         struct attribute_group grp;
1446         unsigned int nsections;
1447         struct module_sect_attr attrs[0];
1448 };
1449 
1450 static ssize_t module_sect_show(struct module_attribute *mattr,
1451                                 struct module_kobject *mk, char *buf)
1452 {
1453         struct module_sect_attr *sattr =
1454                 container_of(mattr, struct module_sect_attr, mattr);
1455         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1456 }
1457 
1458 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1459 {
1460         unsigned int section;
1461 
1462         for (section = 0; section < sect_attrs->nsections; section++)
1463                 kfree(sect_attrs->attrs[section].name);
1464         kfree(sect_attrs);
1465 }
1466 
1467 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1468 {
1469         unsigned int nloaded = 0, i, size[2];
1470         struct module_sect_attrs *sect_attrs;
1471         struct module_sect_attr *sattr;
1472         struct attribute **gattr;
1473 
1474         /* Count loaded sections and allocate structures */
1475         for (i = 0; i < info->hdr->e_shnum; i++)
1476                 if (!sect_empty(&info->sechdrs[i]))
1477                         nloaded++;
1478         size[0] = ALIGN(sizeof(*sect_attrs)
1479                         + nloaded * sizeof(sect_attrs->attrs[0]),
1480                         sizeof(sect_attrs->grp.attrs[0]));
1481         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1482         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1483         if (sect_attrs == NULL)
1484                 return;
1485 
1486         /* Setup section attributes. */
1487         sect_attrs->grp.name = "sections";
1488         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1489 
1490         sect_attrs->nsections = 0;
1491         sattr = &sect_attrs->attrs[0];
1492         gattr = &sect_attrs->grp.attrs[0];
1493         for (i = 0; i < info->hdr->e_shnum; i++) {
1494                 Elf_Shdr *sec = &info->sechdrs[i];
1495                 if (sect_empty(sec))
1496                         continue;
1497                 sattr->address = sec->sh_addr;
1498                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1499                                         GFP_KERNEL);
1500                 if (sattr->name == NULL)
1501                         goto out;
1502                 sect_attrs->nsections++;
1503                 sysfs_attr_init(&sattr->mattr.attr);
1504                 sattr->mattr.show = module_sect_show;
1505                 sattr->mattr.store = NULL;
1506                 sattr->mattr.attr.name = sattr->name;
1507                 sattr->mattr.attr.mode = S_IRUGO;
1508                 *(gattr++) = &(sattr++)->mattr.attr;
1509         }
1510         *gattr = NULL;
1511 
1512         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1513                 goto out;
1514 
1515         mod->sect_attrs = sect_attrs;
1516         return;
1517   out:
1518         free_sect_attrs(sect_attrs);
1519 }
1520 
1521 static void remove_sect_attrs(struct module *mod)
1522 {
1523         if (mod->sect_attrs) {
1524                 sysfs_remove_group(&mod->mkobj.kobj,
1525                                    &mod->sect_attrs->grp);
1526                 /* We are positive that no one is using any sect attrs
1527                  * at this point.  Deallocate immediately. */
1528                 free_sect_attrs(mod->sect_attrs);
1529                 mod->sect_attrs = NULL;
1530         }
1531 }
1532 
1533 /*
1534  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1535  */
1536 
1537 struct module_notes_attrs {
1538         struct kobject *dir;
1539         unsigned int notes;
1540         struct bin_attribute attrs[0];
1541 };
1542 
1543 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1544                                  struct bin_attribute *bin_attr,
1545                                  char *buf, loff_t pos, size_t count)
1546 {
1547         /*
1548          * The caller checked the pos and count against our size.
1549          */
1550         memcpy(buf, bin_attr->private + pos, count);
1551         return count;
1552 }
1553 
1554 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1555                              unsigned int i)
1556 {
1557         if (notes_attrs->dir) {
1558                 while (i-- > 0)
1559                         sysfs_remove_bin_file(notes_attrs->dir,
1560                                               &notes_attrs->attrs[i]);
1561                 kobject_put(notes_attrs->dir);
1562         }
1563         kfree(notes_attrs);
1564 }
1565 
1566 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1567 {
1568         unsigned int notes, loaded, i;
1569         struct module_notes_attrs *notes_attrs;
1570         struct bin_attribute *nattr;
1571 
1572         /* failed to create section attributes, so can't create notes */
1573         if (!mod->sect_attrs)
1574                 return;
1575 
1576         /* Count notes sections and allocate structures.  */
1577         notes = 0;
1578         for (i = 0; i < info->hdr->e_shnum; i++)
1579                 if (!sect_empty(&info->sechdrs[i]) &&
1580                     (info->sechdrs[i].sh_type == SHT_NOTE))
1581                         ++notes;
1582 
1583         if (notes == 0)
1584                 return;
1585 
1586         notes_attrs = kzalloc(sizeof(*notes_attrs)
1587                               + notes * sizeof(notes_attrs->attrs[0]),
1588                               GFP_KERNEL);
1589         if (notes_attrs == NULL)
1590                 return;
1591 
1592         notes_attrs->notes = notes;
1593         nattr = &notes_attrs->attrs[0];
1594         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1595                 if (sect_empty(&info->sechdrs[i]))
1596                         continue;
1597                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1598                         sysfs_bin_attr_init(nattr);
1599                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1600                         nattr->attr.mode = S_IRUGO;
1601                         nattr->size = info->sechdrs[i].sh_size;
1602                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1603                         nattr->read = module_notes_read;
1604                         ++nattr;
1605                 }
1606                 ++loaded;
1607         }
1608 
1609         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1610         if (!notes_attrs->dir)
1611                 goto out;
1612 
1613         for (i = 0; i < notes; ++i)
1614                 if (sysfs_create_bin_file(notes_attrs->dir,
1615                                           &notes_attrs->attrs[i]))
1616                         goto out;
1617 
1618         mod->notes_attrs = notes_attrs;
1619         return;
1620 
1621   out:
1622         free_notes_attrs(notes_attrs, i);
1623 }
1624 
1625 static void remove_notes_attrs(struct module *mod)
1626 {
1627         if (mod->notes_attrs)
1628                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1629 }
1630 
1631 #else
1632 
1633 static inline void add_sect_attrs(struct module *mod,
1634                                   const struct load_info *info)
1635 {
1636 }
1637 
1638 static inline void remove_sect_attrs(struct module *mod)
1639 {
1640 }
1641 
1642 static inline void add_notes_attrs(struct module *mod,
1643                                    const struct load_info *info)
1644 {
1645 }
1646 
1647 static inline void remove_notes_attrs(struct module *mod)
1648 {
1649 }
1650 #endif /* CONFIG_KALLSYMS */
1651 
1652 static void add_usage_links(struct module *mod)
1653 {
1654 #ifdef CONFIG_MODULE_UNLOAD
1655         struct module_use *use;
1656         int nowarn;
1657 
1658         mutex_lock(&module_mutex);
1659         list_for_each_entry(use, &mod->target_list, target_list) {
1660                 nowarn = sysfs_create_link(use->target->holders_dir,
1661                                            &mod->mkobj.kobj, mod->name);
1662         }
1663         mutex_unlock(&module_mutex);
1664 #endif
1665 }
1666 
1667 static void del_usage_links(struct module *mod)
1668 {
1669 #ifdef CONFIG_MODULE_UNLOAD
1670         struct module_use *use;
1671 
1672         mutex_lock(&module_mutex);
1673         list_for_each_entry(use, &mod->target_list, target_list)
1674                 sysfs_remove_link(use->target->holders_dir, mod->name);
1675         mutex_unlock(&module_mutex);
1676 #endif
1677 }
1678 
1679 static int module_add_modinfo_attrs(struct module *mod)
1680 {
1681         struct module_attribute *attr;
1682         struct module_attribute *temp_attr;
1683         int error = 0;
1684         int i;
1685 
1686         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1687                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1688                                         GFP_KERNEL);
1689         if (!mod->modinfo_attrs)
1690                 return -ENOMEM;
1691 
1692         temp_attr = mod->modinfo_attrs;
1693         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1694                 if (!attr->test ||
1695                     (attr->test && attr->test(mod))) {
1696                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1697                         sysfs_attr_init(&temp_attr->attr);
1698                         error = sysfs_create_file(&mod->mkobj.kobj,
1699                                         &temp_attr->attr);
1700                         ++temp_attr;
1701                 }
1702         }
1703         return error;
1704 }
1705 
1706 static void module_remove_modinfo_attrs(struct module *mod)
1707 {
1708         struct module_attribute *attr;
1709         int i;
1710 
1711         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1712                 /* pick a field to test for end of list */
1713                 if (!attr->attr.name)
1714                         break;
1715                 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1716                 if (attr->free)
1717                         attr->free(mod);
1718         }
1719         kfree(mod->modinfo_attrs);
1720 }
1721 
1722 static void mod_kobject_put(struct module *mod)
1723 {
1724         DECLARE_COMPLETION_ONSTACK(c);
1725         mod->mkobj.kobj_completion = &c;
1726         kobject_put(&mod->mkobj.kobj);
1727         wait_for_completion(&c);
1728 }
1729 
1730 static int mod_sysfs_init(struct module *mod)
1731 {
1732         int err;
1733         struct kobject *kobj;
1734 
1735         if (!module_sysfs_initialized) {
1736                 pr_err("%s: module sysfs not initialized\n", mod->name);
1737                 err = -EINVAL;
1738                 goto out;
1739         }
1740 
1741         kobj = kset_find_obj(module_kset, mod->name);
1742         if (kobj) {
1743                 pr_err("%s: module is already loaded\n", mod->name);
1744                 kobject_put(kobj);
1745                 err = -EINVAL;
1746                 goto out;
1747         }
1748 
1749         mod->mkobj.mod = mod;
1750 
1751         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1752         mod->mkobj.kobj.kset = module_kset;
1753         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1754                                    "%s", mod->name);
1755         if (err)
1756                 mod_kobject_put(mod);
1757 
1758         /* delay uevent until full sysfs population */
1759 out:
1760         return err;
1761 }
1762 
1763 static int mod_sysfs_setup(struct module *mod,
1764                            const struct load_info *info,
1765                            struct kernel_param *kparam,
1766                            unsigned int num_params)
1767 {
1768         int err;
1769 
1770         err = mod_sysfs_init(mod);
1771         if (err)
1772                 goto out;
1773 
1774         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1775         if (!mod->holders_dir) {
1776                 err = -ENOMEM;
1777                 goto out_unreg;
1778         }
1779 
1780         err = module_param_sysfs_setup(mod, kparam, num_params);
1781         if (err)
1782                 goto out_unreg_holders;
1783 
1784         err = module_add_modinfo_attrs(mod);
1785         if (err)
1786                 goto out_unreg_param;
1787 
1788         add_usage_links(mod);
1789         add_sect_attrs(mod, info);
1790         add_notes_attrs(mod, info);
1791 
1792         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1793         return 0;
1794 
1795 out_unreg_param:
1796         module_param_sysfs_remove(mod);
1797 out_unreg_holders:
1798         kobject_put(mod->holders_dir);
1799 out_unreg:
1800         mod_kobject_put(mod);
1801 out:
1802         return err;
1803 }
1804 
1805 static void mod_sysfs_fini(struct module *mod)
1806 {
1807         remove_notes_attrs(mod);
1808         remove_sect_attrs(mod);
1809         mod_kobject_put(mod);
1810 }
1811 
1812 static void init_param_lock(struct module *mod)
1813 {
1814         mutex_init(&mod->param_lock);
1815 }
1816 #else /* !CONFIG_SYSFS */
1817 
1818 static int mod_sysfs_setup(struct module *mod,
1819                            const struct load_info *info,
1820                            struct kernel_param *kparam,
1821                            unsigned int num_params)
1822 {
1823         return 0;
1824 }
1825 
1826 static void mod_sysfs_fini(struct module *mod)
1827 {
1828 }
1829 
1830 static void module_remove_modinfo_attrs(struct module *mod)
1831 {
1832 }
1833 
1834 static void del_usage_links(struct module *mod)
1835 {
1836 }
1837 
1838 static void init_param_lock(struct module *mod)
1839 {
1840 }
1841 #endif /* CONFIG_SYSFS */
1842 
1843 static void mod_sysfs_teardown(struct module *mod)
1844 {
1845         del_usage_links(mod);
1846         module_remove_modinfo_attrs(mod);
1847         module_param_sysfs_remove(mod);
1848         kobject_put(mod->mkobj.drivers_dir);
1849         kobject_put(mod->holders_dir);
1850         mod_sysfs_fini(mod);
1851 }
1852 
1853 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1854 /*
1855  * LKM RO/NX protection: protect module's text/ro-data
1856  * from modification and any data from execution.
1857  *
1858  * General layout of module is:
1859  *          [text] [read-only-data] [writable data]
1860  * text_size -----^                ^               ^
1861  * ro_size ------------------------|               |
1862  * size -------------------------------------------|
1863  *
1864  * These values are always page-aligned (as is base)
1865  */
1866 static void frob_text(const struct module_layout *layout,
1867                       int (*set_memory)(unsigned long start, int num_pages))
1868 {
1869         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1870         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1871         set_memory((unsigned long)layout->base,
1872                    layout->text_size >> PAGE_SHIFT);
1873 }
1874 
1875 static void frob_rodata(const struct module_layout *layout,
1876                         int (*set_memory)(unsigned long start, int num_pages))
1877 {
1878         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1879         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1880         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1881         set_memory((unsigned long)layout->base + layout->text_size,
1882                    (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1883 }
1884 
1885 static void frob_writable_data(const struct module_layout *layout,
1886                                int (*set_memory)(unsigned long start, int num_pages))
1887 {
1888         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1889         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1890         BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1891         set_memory((unsigned long)layout->base + layout->ro_size,
1892                    (layout->size - layout->ro_size) >> PAGE_SHIFT);
1893 }
1894 
1895 /* livepatching wants to disable read-only so it can frob module. */
1896 void module_disable_ro(const struct module *mod)
1897 {
1898         frob_text(&mod->core_layout, set_memory_rw);
1899         frob_rodata(&mod->core_layout, set_memory_rw);
1900         frob_text(&mod->init_layout, set_memory_rw);
1901         frob_rodata(&mod->init_layout, set_memory_rw);
1902 }
1903 
1904 void module_enable_ro(const struct module *mod)
1905 {
1906         frob_text(&mod->core_layout, set_memory_ro);
1907         frob_rodata(&mod->core_layout, set_memory_ro);
1908         frob_text(&mod->init_layout, set_memory_ro);
1909         frob_rodata(&mod->init_layout, set_memory_ro);
1910 }
1911 
1912 static void module_enable_nx(const struct module *mod)
1913 {
1914         frob_rodata(&mod->core_layout, set_memory_nx);
1915         frob_writable_data(&mod->core_layout, set_memory_nx);
1916         frob_rodata(&mod->init_layout, set_memory_nx);
1917         frob_writable_data(&mod->init_layout, set_memory_nx);
1918 }
1919 
1920 static void module_disable_nx(const struct module *mod)
1921 {
1922         frob_rodata(&mod->core_layout, set_memory_x);
1923         frob_writable_data(&mod->core_layout, set_memory_x);
1924         frob_rodata(&mod->init_layout, set_memory_x);
1925         frob_writable_data(&mod->init_layout, set_memory_x);
1926 }
1927 
1928 /* Iterate through all modules and set each module's text as RW */
1929 void set_all_modules_text_rw(void)
1930 {
1931         struct module *mod;
1932 
1933         mutex_lock(&module_mutex);
1934         list_for_each_entry_rcu(mod, &modules, list) {
1935                 if (mod->state == MODULE_STATE_UNFORMED)
1936                         continue;
1937 
1938                 frob_text(&mod->core_layout, set_memory_rw);
1939                 frob_text(&mod->init_layout, set_memory_rw);
1940         }
1941         mutex_unlock(&module_mutex);
1942 }
1943 
1944 /* Iterate through all modules and set each module's text as RO */
1945 void set_all_modules_text_ro(void)
1946 {
1947         struct module *mod;
1948 
1949         mutex_lock(&module_mutex);
1950         list_for_each_entry_rcu(mod, &modules, list) {
1951                 if (mod->state == MODULE_STATE_UNFORMED)
1952                         continue;
1953 
1954                 frob_text(&mod->core_layout, set_memory_ro);
1955                 frob_text(&mod->init_layout, set_memory_ro);
1956         }
1957         mutex_unlock(&module_mutex);
1958 }
1959 
1960 static void disable_ro_nx(const struct module_layout *layout)
1961 {
1962         frob_text(layout, set_memory_rw);
1963         frob_rodata(layout, set_memory_rw);
1964         frob_rodata(layout, set_memory_x);
1965         frob_writable_data(layout, set_memory_x);
1966 }
1967 
1968 #else
1969 static void disable_ro_nx(const struct module_layout *layout) { }
1970 static void module_enable_nx(const struct module *mod) { }
1971 static void module_disable_nx(const struct module *mod) { }
1972 #endif
1973 
1974 void __weak module_memfree(void *module_region)
1975 {
1976         vfree(module_region);
1977 }
1978 
1979 void __weak module_arch_cleanup(struct module *mod)
1980 {
1981 }
1982 
1983 void __weak module_arch_freeing_init(struct module *mod)
1984 {
1985 }
1986 
1987 /* Free a module, remove from lists, etc. */
1988 static void free_module(struct module *mod)
1989 {
1990         trace_module_free(mod);
1991 
1992         mod_sysfs_teardown(mod);
1993 
1994         /* We leave it in list to prevent duplicate loads, but make sure
1995          * that noone uses it while it's being deconstructed. */
1996         mutex_lock(&module_mutex);
1997         mod->state = MODULE_STATE_UNFORMED;
1998         mutex_unlock(&module_mutex);
1999 
2000         /* Remove dynamic debug info */
2001         ddebug_remove_module(mod->name);
2002 
2003         /* Arch-specific cleanup. */
2004         module_arch_cleanup(mod);
2005 
2006         /* Module unload stuff */
2007         module_unload_free(mod);
2008 
2009         /* Free any allocated parameters. */
2010         destroy_params(mod->kp, mod->num_kp);
2011 
2012         /* Now we can delete it from the lists */
2013         mutex_lock(&module_mutex);
2014         /* Unlink carefully: kallsyms could be walking list. */
2015         list_del_rcu(&mod->list);
2016         mod_tree_remove(mod);
2017         /* Remove this module from bug list, this uses list_del_rcu */
2018         module_bug_cleanup(mod);
2019         /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2020         synchronize_sched();
2021         mutex_unlock(&module_mutex);
2022 
2023         /* This may be empty, but that's OK */
2024         disable_ro_nx(&mod->init_layout);
2025         module_arch_freeing_init(mod);
2026         module_memfree(mod->init_layout.base);
2027         kfree(mod->args);
2028         percpu_modfree(mod);
2029 
2030         /* Free lock-classes; relies on the preceding sync_rcu(). */
2031         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2032 
2033         /* Finally, free the core (containing the module structure) */
2034         disable_ro_nx(&mod->core_layout);
2035         module_memfree(mod->core_layout.base);
2036 
2037 #ifdef CONFIG_MPU
2038         update_protections(current->mm);
2039 #endif
2040 }
2041 
2042 void *__symbol_get(const char *symbol)
2043 {
2044         struct module *owner;
2045         const struct kernel_symbol *sym;
2046 
2047         preempt_disable();
2048         sym = find_symbol(symbol, &owner, NULL, true, true);
2049         if (sym && strong_try_module_get(owner))
2050                 sym = NULL;
2051         preempt_enable();
2052 
2053         return sym ? (void *)sym->value : NULL;
2054 }
2055 EXPORT_SYMBOL_GPL(__symbol_get);
2056 
2057 /*
2058  * Ensure that an exported symbol [global namespace] does not already exist
2059  * in the kernel or in some other module's exported symbol table.
2060  *
2061  * You must hold the module_mutex.
2062  */
2063 static int verify_export_symbols(struct module *mod)
2064 {
2065         unsigned int i;
2066         struct module *owner;
2067         const struct kernel_symbol *s;
2068         struct {
2069                 const struct kernel_symbol *sym;
2070                 unsigned int num;
2071         } arr[] = {
2072                 { mod->syms, mod->num_syms },
2073                 { mod->gpl_syms, mod->num_gpl_syms },
2074                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2075 #ifdef CONFIG_UNUSED_SYMBOLS
2076                 { mod->unused_syms, mod->num_unused_syms },
2077                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2078 #endif
2079         };
2080 
2081         for (i = 0; i < ARRAY_SIZE(arr); i++) {
2082                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2083                         if (find_symbol(s->name, &owner, NULL, true, false)) {
2084                                 pr_err("%s: exports duplicate symbol %s"
2085                                        " (owned by %s)\n",
2086                                        mod->name, s->name, module_name(owner));
2087                                 return -ENOEXEC;
2088                         }
2089                 }
2090         }
2091         return 0;
2092 }
2093 
2094 /* Change all symbols so that st_value encodes the pointer directly. */
2095 static int simplify_symbols(struct module *mod, const struct load_info *info)
2096 {
2097         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2098         Elf_Sym *sym = (void *)symsec->sh_addr;
2099         unsigned long secbase;
2100         unsigned int i;
2101         int ret = 0;
2102         const struct kernel_symbol *ksym;
2103 
2104         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2105                 const char *name = info->strtab + sym[i].st_name;
2106 
2107                 switch (sym[i].st_shndx) {
2108                 case SHN_COMMON:
2109                         /* Ignore common symbols */
2110                         if (!strncmp(name, "__gnu_lto", 9))
2111                                 break;
2112 
2113                         /* We compiled with -fno-common.  These are not
2114                            supposed to happen.  */
2115                         pr_debug("Common symbol: %s\n", name);
2116                         pr_warn("%s: please compile with -fno-common\n",
2117                                mod->name);
2118                         ret = -ENOEXEC;
2119                         break;
2120 
2121                 case SHN_ABS:
2122                         /* Don't need to do anything */
2123                         pr_debug("Absolute symbol: 0x%08lx\n",
2124                                (long)sym[i].st_value);
2125                         break;
2126 
2127                 case SHN_UNDEF:
2128                         ksym = resolve_symbol_wait(mod, info, name);
2129                         /* Ok if resolved.  */
2130                         if (ksym && !IS_ERR(ksym)) {
2131                                 sym[i].st_value = ksym->value;
2132                                 break;
2133                         }
2134 
2135                         /* Ok if weak.  */
2136                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2137                                 break;
2138 
2139                         pr_warn("%s: Unknown symbol %s (err %li)\n",
2140                                 mod->name, name, PTR_ERR(ksym));
2141                         ret = PTR_ERR(ksym) ?: -ENOENT;
2142                         break;
2143 
2144                 default:
2145                         /* Divert to percpu allocation if a percpu var. */
2146                         if (sym[i].st_shndx == info->index.pcpu)
2147                                 secbase = (unsigned long)mod_percpu(mod);
2148                         else
2149                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2150                         sym[i].st_value += secbase;
2151                         break;
2152                 }
2153         }
2154 
2155         return ret;
2156 }
2157 
2158 static int apply_relocations(struct module *mod, const struct load_info *info)
2159 {
2160         unsigned int i;
2161         int err = 0;
2162 
2163         /* Now do relocations. */
2164         for (i = 1; i < info->hdr->e_shnum; i++) {
2165                 unsigned int infosec = info->sechdrs[i].sh_info;
2166 
2167                 /* Not a valid relocation section? */
2168                 if (infosec >= info->hdr->e_shnum)
2169                         continue;
2170 
2171                 /* Don't bother with non-allocated sections */
2172                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2173                         continue;
2174 
2175                 if (info->sechdrs[i].sh_type == SHT_REL)
2176                         err = apply_relocate(info->sechdrs, info->strtab,
2177                                              info->index.sym, i, mod);
2178                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2179                         err = apply_relocate_add(info->sechdrs, info->strtab,
2180                                                  info->index.sym, i, mod);
2181                 if (err < 0)
2182                         break;
2183         }
2184         return err;
2185 }
2186 
2187 /* Additional bytes needed by arch in front of individual sections */
2188 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2189                                              unsigned int section)
2190 {
2191         /* default implementation just returns zero */
2192         return 0;
2193 }
2194 
2195 /* Update size with this section: return offset. */
2196 static long get_offset(struct module *mod, unsigned int *size,
2197                        Elf_Shdr *sechdr, unsigned int section)
2198 {
2199         long ret;
2200 
2201         *size += arch_mod_section_prepend(mod, section);
2202         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2203         *size = ret + sechdr->sh_size;
2204         return ret;
2205 }
2206 
2207 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2208    might -- code, read-only data, read-write data, small data.  Tally
2209    sizes, and place the offsets into sh_entsize fields: high bit means it
2210    belongs in init. */
2211 static void layout_sections(struct module *mod, struct load_info *info)
2212 {
2213         static unsigned long const masks[][2] = {
2214                 /* NOTE: all executable code must be the first section
2215                  * in this array; otherwise modify the text_size
2216                  * finder in the two loops below */
2217                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2218                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2219                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2220                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2221         };
2222         unsigned int m, i;
2223 
2224         for (i = 0; i < info->hdr->e_shnum; i++)
2225                 info->sechdrs[i].sh_entsize = ~0UL;
2226 
2227         pr_debug("Core section allocation order:\n");
2228         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2229                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2230                         Elf_Shdr *s = &info->sechdrs[i];
2231                         const char *sname = info->secstrings + s->sh_name;
2232 
2233                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2234                             || (s->sh_flags & masks[m][1])
2235                             || s->sh_entsize != ~0UL
2236                             || strstarts(sname, ".init"))
2237                                 continue;
2238                         s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2239                         pr_debug("\t%s\n", sname);
2240                 }
2241                 switch (m) {
2242                 case 0: /* executable */
2243                         mod->core_layout.size = debug_align(mod->core_layout.size);
2244                         mod->core_layout.text_size = mod->core_layout.size;
2245                         break;
2246                 case 1: /* RO: text and ro-data */
2247                         mod->core_layout.size = debug_align(mod->core_layout.size);
2248                         mod->core_layout.ro_size = mod->core_layout.size;
2249                         break;
2250                 case 3: /* whole core */
2251                         mod->core_layout.size = debug_align(mod->core_layout.size);
2252                         break;
2253                 }
2254         }
2255 
2256         pr_debug("Init section allocation order:\n");
2257         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2258                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2259                         Elf_Shdr *s = &info->sechdrs[i];
2260                         const char *sname = info->secstrings + s->sh_name;
2261 
2262                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2263                             || (s->sh_flags & masks[m][1])
2264                             || s->sh_entsize != ~0UL
2265                             || !strstarts(sname, ".init"))
2266                                 continue;
2267                         s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2268                                          | INIT_OFFSET_MASK);
2269                         pr_debug("\t%s\n", sname);
2270                 }
2271                 switch (m) {
2272                 case 0: /* executable */
2273                         mod->init_layout.size = debug_align(mod->init_layout.size);
2274                         mod->init_layout.text_size = mod->init_layout.size;
2275                         break;
2276                 case 1: /* RO: text and ro-data */
2277                         mod->init_layout.size = debug_align(mod->init_layout.size);
2278                         mod->init_layout.ro_size = mod->init_layout.size;
2279                         break;
2280                 case 3: /* whole init */
2281                         mod->init_layout.size = debug_align(mod->init_layout.size);
2282                         break;
2283                 }
2284         }
2285 }
2286 
2287 static void set_license(struct module *mod, const char *license)
2288 {
2289         if (!license)
2290                 license = "unspecified";
2291 
2292         if (!license_is_gpl_compatible(license)) {
2293                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2294                         pr_warn("%s: module license '%s' taints kernel.\n",
2295                                 mod->name, license);
2296                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2297                                  LOCKDEP_NOW_UNRELIABLE);
2298         }
2299 }
2300 
2301 /* Parse tag=value strings from .modinfo section */
2302 static char *next_string(char *string, unsigned long *secsize)
2303 {
2304         /* Skip non-zero chars */
2305         while (string[0]) {
2306                 string++;
2307                 if ((*secsize)-- <= 1)
2308                         return NULL;
2309         }
2310 
2311         /* Skip any zero padding. */
2312         while (!string[0]) {
2313                 string++;
2314                 if ((*secsize)-- <= 1)
2315                         return NULL;
2316         }
2317         return string;
2318 }
2319 
2320 static char *get_modinfo(struct load_info *info, const char *tag)
2321 {
2322         char *p;
2323         unsigned int taglen = strlen(tag);
2324         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2325         unsigned long size = infosec->sh_size;
2326 
2327         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2328                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2329                         return p + taglen + 1;
2330         }
2331         return NULL;
2332 }
2333 
2334 static void setup_modinfo(struct module *mod, struct load_info *info)
2335 {
2336         struct module_attribute *attr;
2337         int i;
2338 
2339         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2340                 if (attr->setup)
2341                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2342         }
2343 }
2344 
2345 static void free_modinfo(struct module *mod)
2346 {
2347         struct module_attribute *attr;
2348         int i;
2349 
2350         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2351                 if (attr->free)
2352                         attr->free(mod);
2353         }
2354 }
2355 
2356 #ifdef CONFIG_KALLSYMS
2357 
2358 /* lookup symbol in given range of kernel_symbols */
2359 static const struct kernel_symbol *lookup_symbol(const char *name,
2360         const struct kernel_symbol *start,
2361         const struct kernel_symbol *stop)
2362 {
2363         return bsearch(name, start, stop - start,
2364                         sizeof(struct kernel_symbol), cmp_name);
2365 }
2366 
2367 static int is_exported(const char *name, unsigned long value,
2368                        const struct module *mod)
2369 {
2370         const struct kernel_symbol *ks;
2371         if (!mod)
2372                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2373         else
2374                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2375         return ks != NULL && ks->value == value;
2376 }
2377 
2378 /* As per nm */
2379 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2380 {
2381         const Elf_Shdr *sechdrs = info->sechdrs;
2382 
2383         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2384                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2385                         return 'v';
2386                 else
2387                         return 'w';
2388         }
2389         if (sym->st_shndx == SHN_UNDEF)
2390                 return 'U';
2391         if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2392                 return 'a';
2393         if (sym->st_shndx >= SHN_LORESERVE)
2394                 return '?';
2395         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2396                 return 't';
2397         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2398             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2399                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2400                         return 'r';
2401                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2402                         return 'g';
2403                 else
2404                         return 'd';
2405         }
2406         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2407                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2408                         return 's';
2409                 else
2410                         return 'b';
2411         }
2412         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2413                       ".debug")) {
2414                 return 'n';
2415         }
2416         return '?';
2417 }
2418 
2419 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2420                         unsigned int shnum, unsigned int pcpundx)
2421 {
2422         const Elf_Shdr *sec;
2423 
2424         if (src->st_shndx == SHN_UNDEF
2425             || src->st_shndx >= shnum
2426             || !src->st_name)
2427                 return false;
2428 
2429 #ifdef CONFIG_KALLSYMS_ALL
2430         if (src->st_shndx == pcpundx)
2431                 return true;
2432 #endif
2433 
2434         sec = sechdrs + src->st_shndx;
2435         if (!(sec->sh_flags & SHF_ALLOC)
2436 #ifndef CONFIG_KALLSYMS_ALL
2437             || !(sec->sh_flags & SHF_EXECINSTR)
2438 #endif
2439             || (sec->sh_entsize & INIT_OFFSET_MASK))
2440                 return false;
2441 
2442         return true;
2443 }
2444 
2445 /*
2446  * We only allocate and copy the strings needed by the parts of symtab
2447  * we keep.  This is simple, but has the effect of making multiple
2448  * copies of duplicates.  We could be more sophisticated, see
2449  * linux-kernel thread starting with
2450  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2451  */
2452 static void layout_symtab(struct module *mod, struct load_info *info)
2453 {
2454         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2455         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2456         const Elf_Sym *src;
2457         unsigned int i, nsrc, ndst, strtab_size = 0;
2458 
2459         /* Put symbol section at end of init part of module. */
2460         symsect->sh_flags |= SHF_ALLOC;
2461         symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2462                                          info->index.sym) | INIT_OFFSET_MASK;
2463         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2464 
2465         src = (void *)info->hdr + symsect->sh_offset;
2466         nsrc = symsect->sh_size / sizeof(*src);
2467 
2468         /* Compute total space required for the core symbols' strtab. */
2469         for (ndst = i = 0; i < nsrc; i++) {
2470                 if (i == 0 ||
2471                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2472                                    info->index.pcpu)) {
2473                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2474                         ndst++;
2475                 }
2476         }
2477 
2478         /* Append room for core symbols at end of core part. */
2479         info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2480         info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2481         mod->core_layout.size += strtab_size;
2482         mod->core_layout.size = debug_align(mod->core_layout.size);
2483 
2484         /* Put string table section at end of init part of module. */
2485         strsect->sh_flags |= SHF_ALLOC;
2486         strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2487                                          info->index.str) | INIT_OFFSET_MASK;
2488         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2489 
2490         /* We'll tack temporary mod_kallsyms on the end. */
2491         mod->init_layout.size = ALIGN(mod->init_layout.size,
2492                                       __alignof__(struct mod_kallsyms));
2493         info->mod_kallsyms_init_off = mod->init_layout.size;
2494         mod->init_layout.size += sizeof(struct mod_kallsyms);
2495         mod->init_layout.size = debug_align(mod->init_layout.size);
2496 }
2497 
2498 /*
2499  * We use the full symtab and strtab which layout_symtab arranged to
2500  * be appended to the init section.  Later we switch to the cut-down
2501  * core-only ones.
2502  */
2503 static void add_kallsyms(struct module *mod, const struct load_info *info)
2504 {
2505         unsigned int i, ndst;
2506         const Elf_Sym *src;
2507         Elf_Sym *dst;
2508         char *s;
2509         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2510 
2511         /* Set up to point into init section. */
2512         mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2513 
2514         mod->kallsyms->symtab = (void *)symsec->sh_addr;
2515         mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2516         /* Make sure we get permanent strtab: don't use info->strtab. */
2517         mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2518 
2519         /* Set types up while we still have access to sections. */
2520         for (i = 0; i < mod->kallsyms->num_symtab; i++)
2521                 mod->kallsyms->symtab[i].st_info
2522                         = elf_type(&mod->kallsyms->symtab[i], info);
2523 
2524         /* Now populate the cut down core kallsyms for after init. */
2525         mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2526         mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2527         src = mod->kallsyms->symtab;
2528         for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2529                 if (i == 0 ||
2530                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2531                                    info->index.pcpu)) {
2532                         dst[ndst] = src[i];
2533                         dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2534                         s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2535                                      KSYM_NAME_LEN) + 1;
2536                 }
2537         }
2538         mod->core_kallsyms.num_symtab = ndst;
2539 }
2540 #else
2541 static inline void layout_symtab(struct module *mod, struct load_info *info)
2542 {
2543 }
2544 
2545 static void add_kallsyms(struct module *mod, const struct load_info *info)
2546 {
2547 }
2548 #endif /* CONFIG_KALLSYMS */
2549 
2550 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2551 {
2552         if (!debug)
2553                 return;
2554 #ifdef CONFIG_DYNAMIC_DEBUG
2555         if (ddebug_add_module(debug, num, debug->modname))
2556                 pr_err("dynamic debug error adding module: %s\n",
2557                         debug->modname);
2558 #endif
2559 }
2560 
2561 static void dynamic_debug_remove(struct _ddebug *debug)
2562 {
2563         if (debug)
2564                 ddebug_remove_module(debug->modname);
2565 }
2566 
2567 void * __weak module_alloc(unsigned long size)
2568 {
2569         return vmalloc_exec(size);
2570 }
2571 
2572 #ifdef CONFIG_DEBUG_KMEMLEAK
2573 static void kmemleak_load_module(const struct module *mod,
2574                                  const struct load_info *info)
2575 {
2576         unsigned int i;
2577 
2578         /* only scan the sections containing data */
2579         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2580 
2581         for (i = 1; i < info->hdr->e_shnum; i++) {
2582                 /* Scan all writable sections that's not executable */
2583                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2584                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2585                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2586                         continue;
2587 
2588                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2589                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2590         }
2591 }
2592 #else
2593 static inline void kmemleak_load_module(const struct module *mod,
2594                                         const struct load_info *info)
2595 {
2596 }
2597 #endif
2598 
2599 #ifdef CONFIG_MODULE_SIG
2600 static int module_sig_check(struct load_info *info)
2601 {
2602         int err = -ENOKEY;
2603         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2604         const void *mod = info->hdr;
2605 
2606         if (info->len > markerlen &&
2607             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2608                 /* We truncate the module to discard the signature */
2609                 info->len -= markerlen;
2610                 err = mod_verify_sig(mod, &info->len);
2611         }
2612 
2613         if (!err) {
2614                 info->sig_ok = true;
2615                 return 0;
2616         }
2617 
2618         /* Not having a signature is only an error if we're strict. */
2619         if (err == -ENOKEY && !sig_enforce)
2620                 err = 0;
2621 
2622         return err;
2623 }
2624 #else /* !CONFIG_MODULE_SIG */
2625 static int module_sig_check(struct load_info *info)
2626 {
2627         return 0;
2628 }
2629 #endif /* !CONFIG_MODULE_SIG */
2630 
2631 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2632 static int elf_header_check(struct load_info *info)
2633 {
2634         if (info->len < sizeof(*(info->hdr)))
2635                 return -ENOEXEC;
2636 
2637         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2638             || info->hdr->e_type != ET_REL
2639             || !elf_check_arch(info->hdr)
2640             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2641                 return -ENOEXEC;
2642 
2643         if (info->hdr->e_shoff >= info->len
2644             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2645                 info->len - info->hdr->e_shoff))
2646                 return -ENOEXEC;
2647 
2648         return 0;
2649 }
2650 
2651 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2652 
2653 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2654 {
2655         do {
2656                 unsigned long n = min(len, COPY_CHUNK_SIZE);
2657 
2658                 if (copy_from_user(dst, usrc, n) != 0)
2659                         return -EFAULT;
2660                 cond_resched();
2661                 dst += n;
2662                 usrc += n;
2663                 len -= n;
2664         } while (len);
2665         return 0;
2666 }
2667 
2668 /* Sets info->hdr and info->len. */
2669 static int copy_module_from_user(const void __user *umod, unsigned long len,
2670                                   struct load_info *info)
2671 {
2672         int err;
2673 
2674         info->len = len;
2675         if (info->len < sizeof(*(info->hdr)))
2676                 return -ENOEXEC;
2677 
2678         err = security_kernel_module_from_file(NULL);
2679         if (err)
2680                 return err;
2681 
2682         /* Suck in entire file: we'll want most of it. */
2683         info->hdr = __vmalloc(info->len,
2684                         GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2685         if (!info->hdr)
2686                 return -ENOMEM;
2687 
2688         if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2689                 vfree(info->hdr);
2690                 return -EFAULT;
2691         }
2692 
2693         return 0;
2694 }
2695 
2696 /* Sets info->hdr and info->len. */
2697 static int copy_module_from_fd(int fd, struct load_info *info)
2698 {
2699         struct fd f = fdget(fd);
2700         int err;
2701         struct kstat stat;
2702         loff_t pos;
2703         ssize_t bytes = 0;
2704 
2705         if (!f.file)
2706                 return -ENOEXEC;
2707 
2708         err = security_kernel_module_from_file(f.file);
2709         if (err)
2710                 goto out;
2711 
2712         err = vfs_getattr(&f.file->f_path, &stat);
2713         if (err)
2714                 goto out;
2715 
2716         if (stat.size > INT_MAX) {
2717                 err = -EFBIG;
2718                 goto out;
2719         }
2720 
2721         /* Don't hand 0 to vmalloc, it whines. */
2722         if (stat.size == 0) {
2723                 err = -EINVAL;
2724                 goto out;
2725         }
2726 
2727         info->hdr = vmalloc(stat.size);
2728         if (!info->hdr) {
2729                 err = -ENOMEM;
2730                 goto out;
2731         }
2732 
2733         pos = 0;
2734         while (pos < stat.size) {
2735                 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2736                                     stat.size - pos);
2737                 if (bytes < 0) {
2738                         vfree(info->hdr);
2739                         err = bytes;
2740                         goto out;
2741                 }
2742                 if (bytes == 0)
2743                         break;
2744                 pos += bytes;
2745         }
2746         info->len = pos;
2747 
2748 out:
2749         fdput(f);
2750         return err;
2751 }
2752 
2753 static void free_copy(struct load_info *info)
2754 {
2755         vfree(info->hdr);
2756 }
2757 
2758 static int rewrite_section_headers(struct load_info *info, int flags)
2759 {
2760         unsigned int i;
2761 
2762         /* This should always be true, but let's be sure. */
2763         info->sechdrs[0].sh_addr = 0;
2764 
2765         for (i = 1; i < info->hdr->e_shnum; i++) {
2766                 Elf_Shdr *shdr = &info->sechdrs[i];
2767                 if (shdr->sh_type != SHT_NOBITS
2768                     && info->len < shdr->sh_offset + shdr->sh_size) {
2769                         pr_err("Module len %lu truncated\n", info->len);
2770                         return -ENOEXEC;
2771                 }
2772 
2773                 /* Mark all sections sh_addr with their address in the
2774                    temporary image. */
2775                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2776 
2777 #ifndef CONFIG_MODULE_UNLOAD
2778                 /* Don't load .exit sections */
2779                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2780                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2781 #endif
2782         }
2783 
2784         /* Track but don't keep modinfo and version sections. */
2785         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2786                 info->index.vers = 0; /* Pretend no __versions section! */
2787         else
2788                 info->index.vers = find_sec(info, "__versions");
2789         info->index.info = find_sec(info, ".modinfo");
2790         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2791         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2792         return 0;
2793 }
2794 
2795 /*
2796  * Set up our basic convenience variables (pointers to section headers,
2797  * search for module section index etc), and do some basic section
2798  * verification.
2799  *
2800  * Return the temporary module pointer (we'll replace it with the final
2801  * one when we move the module sections around).
2802  */
2803 static struct module *setup_load_info(struct load_info *info, int flags)
2804 {
2805         unsigned int i;
2806         int err;
2807         struct module *mod;
2808 
2809         /* Set up the convenience variables */
2810         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2811         info->secstrings = (void *)info->hdr
2812                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2813 
2814         err = rewrite_section_headers(info, flags);
2815         if (err)
2816                 return ERR_PTR(err);
2817 
2818         /* Find internal symbols and strings. */
2819         for (i = 1; i < info->hdr->e_shnum; i++) {
2820                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2821                         info->index.sym = i;
2822                         info->index.str = info->sechdrs[i].sh_link;
2823                         info->strtab = (char *)info->hdr
2824                                 + info->sechdrs[info->index.str].sh_offset;
2825                         break;
2826                 }
2827         }
2828 
2829         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2830         if (!info->index.mod) {
2831                 pr_warn("No module found in object\n");
2832                 return ERR_PTR(-ENOEXEC);
2833         }
2834         /* This is temporary: point mod into copy of data. */
2835         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2836 
2837         if (info->index.sym == 0) {
2838                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2839                 return ERR_PTR(-ENOEXEC);
2840         }
2841 
2842         info->index.pcpu = find_pcpusec(info);
2843 
2844         /* Check module struct version now, before we try to use module. */
2845         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2846                 return ERR_PTR(-ENOEXEC);
2847 
2848         return mod;
2849 }
2850 
2851 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2852 {
2853         const char *modmagic = get_modinfo(info, "vermagic");
2854         int err;
2855 
2856         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2857                 modmagic = NULL;
2858 
2859         /* This is allowed: modprobe --force will invalidate it. */
2860         if (!modmagic) {
2861                 err = try_to_force_load(mod, "bad vermagic");
2862                 if (err)
2863                         return err;
2864         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2865                 pr_err("%s: version magic '%s' should be '%s'\n",
2866                        mod->name, modmagic, vermagic);
2867                 return -ENOEXEC;
2868         }
2869 
2870         if (!get_modinfo(info, "intree"))
2871                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2872 
2873         if (get_modinfo(info, "staging")) {
2874                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2875                 pr_warn("%s: module is from the staging directory, the quality "
2876                         "is unknown, you have been warned.\n", mod->name);
2877         }
2878 
2879         /* Set up license info based on the info section */
2880         set_license(mod, get_modinfo(info, "license"));
2881 
2882         return 0;
2883 }
2884 
2885 static int find_module_sections(struct module *mod, struct load_info *info)
2886 {
2887         mod->kp = section_objs(info, "__param",
2888                                sizeof(*mod->kp), &mod->num_kp);
2889         mod->syms = section_objs(info, "__ksymtab",
2890                                  sizeof(*mod->syms), &mod->num_syms);
2891         mod->crcs = section_addr(info, "__kcrctab");
2892         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2893                                      sizeof(*mod->gpl_syms),
2894                                      &mod->num_gpl_syms);
2895         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2896         mod->gpl_future_syms = section_objs(info,
2897                                             "__ksymtab_gpl_future",
2898                                             sizeof(*mod->gpl_future_syms),
2899                                             &mod->num_gpl_future_syms);
2900         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2901 
2902 #ifdef CONFIG_UNUSED_SYMBOLS
2903         mod->unused_syms = section_objs(info, "__ksymtab_unused",
2904                                         sizeof(*mod->unused_syms),
2905                                         &mod->num_unused_syms);
2906         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2907         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2908                                             sizeof(*mod->unused_gpl_syms),
2909                                             &mod->num_unused_gpl_syms);
2910         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2911 #endif
2912 #ifdef CONFIG_CONSTRUCTORS
2913         mod->ctors = section_objs(info, ".ctors",
2914                                   sizeof(*mod->ctors), &mod->num_ctors);
2915         if (!mod->ctors)
2916                 mod->ctors = section_objs(info, ".init_array",
2917                                 sizeof(*mod->ctors), &mod->num_ctors);
2918         else if (find_sec(info, ".init_array")) {
2919                 /*
2920                  * This shouldn't happen with same compiler and binutils
2921                  * building all parts of the module.
2922                  */
2923                 pr_warn("%s: has both .ctors and .init_array.\n",
2924                        mod->name);
2925                 return -EINVAL;
2926         }
2927 #endif
2928 
2929 #ifdef CONFIG_TRACEPOINTS
2930         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2931                                              sizeof(*mod->tracepoints_ptrs),
2932                                              &mod->num_tracepoints);
2933 #endif
2934 #ifdef HAVE_JUMP_LABEL
2935         mod->jump_entries = section_objs(info, "__jump_table",
2936                                         sizeof(*mod->jump_entries),
2937                                         &mod->num_jump_entries);
2938 #endif
2939 #ifdef CONFIG_EVENT_TRACING
2940         mod->trace_events = section_objs(info, "_ftrace_events",
2941                                          sizeof(*mod->trace_events),
2942                                          &mod->num_trace_events);
2943         mod->trace_enums = section_objs(info, "_ftrace_enum_map",
2944                                         sizeof(*mod->trace_enums),
2945                                         &mod->num_trace_enums);
2946 #endif
2947 #ifdef CONFIG_TRACING
2948         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2949                                          sizeof(*mod->trace_bprintk_fmt_start),
2950                                          &mod->num_trace_bprintk_fmt);
2951 #endif
2952 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2953         /* sechdrs[0].sh_size is always zero */
2954         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2955                                              sizeof(*mod->ftrace_callsites),
2956                                              &mod->num_ftrace_callsites);
2957 #endif
2958 
2959         mod->extable = section_objs(info, "__ex_table",
2960                                     sizeof(*mod->extable), &mod->num_exentries);
2961 
2962         if (section_addr(info, "__obsparm"))
2963                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2964 
2965         info->debug = section_objs(info, "__verbose",
2966                                    sizeof(*info->debug), &info->num_debug);
2967 
2968         return 0;
2969 }
2970 
2971 static int move_module(struct module *mod, struct load_info *info)
2972 {
2973         int i;
2974         void *ptr;
2975 
2976         /* Do the allocs. */
2977         ptr = module_alloc(mod->core_layout.size);
2978         /*
2979          * The pointer to this block is stored in the module structure
2980          * which is inside the block. Just mark it as not being a
2981          * leak.
2982          */
2983         kmemleak_not_leak(ptr);
2984         if (!ptr)
2985                 return -ENOMEM;
2986 
2987         memset(ptr, 0, mod->core_layout.size);
2988         mod->core_layout.base = ptr;
2989 
2990         if (mod->init_layout.size) {
2991                 ptr = module_alloc(mod->init_layout.size);
2992                 /*
2993                  * The pointer to this block is stored in the module structure
2994                  * which is inside the block. This block doesn't need to be
2995                  * scanned as it contains data and code that will be freed
2996                  * after the module is initialized.
2997                  */
2998                 kmemleak_ignore(ptr);
2999                 if (!ptr) {
3000                         module_memfree(mod->core_layout.base);
3001                         return -ENOMEM;
3002                 }
3003                 memset(ptr, 0, mod->init_layout.size);
3004                 mod->init_layout.base = ptr;
3005         } else
3006                 mod->init_layout.base = NULL;
3007 
3008         /* Transfer each section which specifies SHF_ALLOC */
3009         pr_debug("final section addresses:\n");
3010         for (i = 0; i < info->hdr->e_shnum; i++) {
3011                 void *dest;
3012                 Elf_Shdr *shdr = &info->sechdrs[i];
3013 
3014                 if (!(shdr->sh_flags & SHF_ALLOC))
3015                         continue;
3016 
3017                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3018                         dest = mod->init_layout.base
3019                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3020                 else
3021                         dest = mod->core_layout.base + shdr->sh_entsize;
3022 
3023                 if (shdr->sh_type != SHT_NOBITS)
3024                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3025                 /* Update sh_addr to point to copy in image. */
3026                 shdr->sh_addr = (unsigned long)dest;
3027                 pr_debug("\t0x%lx %s\n",
3028                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3029         }
3030 
3031         return 0;
3032 }
3033 
3034 static int check_module_license_and_versions(struct module *mod)
3035 {
3036         /*
3037          * ndiswrapper is under GPL by itself, but loads proprietary modules.
3038          * Don't use add_taint_module(), as it would prevent ndiswrapper from
3039          * using GPL-only symbols it needs.
3040          */
3041         if (strcmp(mod->name, "ndiswrapper") == 0)
3042                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3043 
3044         /* driverloader was caught wrongly pretending to be under GPL */
3045         if (strcmp(mod->name, "driverloader") == 0)
3046                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3047                                  LOCKDEP_NOW_UNRELIABLE);
3048 
3049         /* lve claims to be GPL but upstream won't provide source */
3050         if (strcmp(mod->name, "lve") == 0)
3051                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3052                                  LOCKDEP_NOW_UNRELIABLE);
3053 
3054 #ifdef CONFIG_MODVERSIONS
3055         if ((mod->num_syms && !mod->crcs)
3056             || (mod->num_gpl_syms && !mod->gpl_crcs)
3057             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3058 #ifdef CONFIG_UNUSED_SYMBOLS
3059             || (mod->num_unused_syms && !mod->unused_crcs)
3060             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3061 #endif
3062                 ) {
3063                 return try_to_force_load(mod,
3064                                          "no versions for exported symbols");
3065         }
3066 #endif
3067         return 0;
3068 }
3069 
3070 static void flush_module_icache(const struct module *mod)
3071 {
3072         mm_segment_t old_fs;
3073 
3074         /* flush the icache in correct context */
3075         old_fs = get_fs();
3076         set_fs(KERNEL_DS);
3077 
3078         /*
3079          * Flush the instruction cache, since we've played with text.
3080          * Do it before processing of module parameters, so the module
3081          * can provide parameter accessor functions of its own.
3082          */
3083         if (mod->init_layout.base)
3084                 flush_icache_range((unsigned long)mod->init_layout.base,
3085                                    (unsigned long)mod->init_layout.base
3086                                    + mod->init_layout.size);
3087         flush_icache_range((unsigned long)mod->core_layout.base,
3088                            (unsigned long)mod->core_layout.base + mod->core_layout.size);
3089 
3090         set_fs(old_fs);
3091 }
3092 
3093 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3094                                      Elf_Shdr *sechdrs,
3095                                      char *secstrings,
3096                                      struct module *mod)
3097 {
3098         return 0;
3099 }
3100 
3101 static struct module *layout_and_allocate(struct load_info *info, int flags)
3102 {
3103         /* Module within temporary copy. */
3104         struct module *mod;
3105         int err;
3106 
3107         mod = setup_load_info(info, flags);
3108         if (IS_ERR(mod))
3109                 return mod;
3110 
3111         err = check_modinfo(mod, info, flags);
3112         if (err)
3113                 return ERR_PTR(err);
3114 
3115         /* Allow arches to frob section contents and sizes.  */
3116         err = module_frob_arch_sections(info->hdr, info->sechdrs,
3117                                         info->secstrings, mod);
3118         if (err < 0)
3119                 return ERR_PTR(err);
3120 
3121         /* We will do a special allocation for per-cpu sections later. */
3122         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3123 
3124         /* Determine total sizes, and put offsets in sh_entsize.  For now
3125            this is done generically; there doesn't appear to be any
3126            special cases for the architectures. */
3127         layout_sections(mod, info);
3128         layout_symtab(mod, info);
3129 
3130         /* Allocate and move to the final place */
3131         err = move_module(mod, info);
3132         if (err)
3133                 return ERR_PTR(err);
3134 
3135         /* Module has been copied to its final place now: return it. */
3136         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3137         kmemleak_load_module(mod, info);
3138         return mod;
3139 }
3140 
3141 /* mod is no longer valid after this! */
3142 static void module_deallocate(struct module *mod, struct load_info *info)
3143 {
3144         percpu_modfree(mod);
3145         module_arch_freeing_init(mod);
3146         module_memfree(mod->init_layout.base);
3147         module_memfree(mod->core_layout.base);
3148 }
3149 
3150 int __weak module_finalize(const Elf_Ehdr *hdr,
3151                            const Elf_Shdr *sechdrs,
3152                            struct module *me)
3153 {
3154         return 0;
3155 }
3156 
3157 static int post_relocation(struct module *mod, const struct load_info *info)
3158 {
3159         /* Sort exception table now relocations are done. */
3160         sort_extable(mod->extable, mod->extable + mod->num_exentries);
3161 
3162         /* Copy relocated percpu area over. */
3163         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3164                        info->sechdrs[info->index.pcpu].sh_size);
3165 
3166         /* Setup kallsyms-specific fields. */
3167         add_kallsyms(mod, info);
3168 
3169         /* Arch-specific module finalizing. */
3170         return module_finalize(info->hdr, info->sechdrs, mod);
3171 }
3172 
3173 /* Is this module of this name done loading?  No locks held. */
3174 static bool finished_loading(const char *name)
3175 {
3176         struct module *mod;
3177         bool ret;
3178 
3179         /*
3180          * The module_mutex should not be a heavily contended lock;
3181          * if we get the occasional sleep here, we'll go an extra iteration
3182          * in the wait_event_interruptible(), which is harmless.
3183          */
3184         sched_annotate_sleep();
3185         mutex_lock(&module_mutex);
3186         mod = find_module_all(name, strlen(name), true);
3187         ret = !mod || mod->state == MODULE_STATE_LIVE
3188                 || mod->state == MODULE_STATE_GOING;
3189         mutex_unlock(&module_mutex);
3190 
3191         return ret;
3192 }
3193 
3194 /* Call module constructors. */
3195 static void do_mod_ctors(struct module *mod)
3196 {
3197 #ifdef CONFIG_CONSTRUCTORS
3198         unsigned long i;
3199 
3200         for (i = 0; i < mod->num_ctors; i++)
3201                 mod->ctors[i]();
3202 #endif
3203 }
3204 
3205 /* For freeing module_init on success, in case kallsyms traversing */
3206 struct mod_initfree {
3207         struct rcu_head rcu;
3208         void *module_init;
3209 };
3210 
3211 static void do_free_init(struct rcu_head *head)
3212 {
3213         struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3214         module_memfree(m->module_init);
3215         kfree(m);
3216 }
3217 
3218 /*
3219  * This is where the real work happens.
3220  *
3221  * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3222  * helper command 'lx-symbols'.
3223  */
3224 static noinline int do_init_module(struct module *mod)
3225 {
3226         int ret = 0;
3227         struct mod_initfree *freeinit;
3228 
3229         freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3230         if (!freeinit) {
3231                 ret = -ENOMEM;
3232                 goto fail;
3233         }
3234         freeinit->module_init = mod->init_layout.base;
3235 
3236         /*
3237          * We want to find out whether @mod uses async during init.  Clear
3238          * PF_USED_ASYNC.  async_schedule*() will set it.
3239          */
3240         current->flags &= ~PF_USED_ASYNC;
3241 
3242         do_mod_ctors(mod);
3243         /* Start the module */
3244         if (mod->init != NULL)
3245                 ret = do_one_initcall(mod->init);
3246         if (ret < 0) {
3247                 goto fail_free_freeinit;
3248         }
3249         if (ret > 0) {
3250                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3251                         "follow 0/-E convention\n"
3252                         "%s: loading module anyway...\n",
3253                         __func__, mod->name, ret, __func__);
3254                 dump_stack();
3255         }
3256 
3257         /* Now it's a first class citizen! */
3258         mod->state = MODULE_STATE_LIVE;
3259         blocking_notifier_call_chain(&module_notify_list,
3260                                      MODULE_STATE_LIVE, mod);
3261 
3262         /*
3263          * We need to finish all async code before the module init sequence
3264          * is done.  This has potential to deadlock.  For example, a newly
3265          * detected block device can trigger request_module() of the
3266          * default iosched from async probing task.  Once userland helper
3267          * reaches here, async_synchronize_full() will wait on the async
3268          * task waiting on request_module() and deadlock.
3269          *
3270          * This deadlock is avoided by perfomring async_synchronize_full()
3271          * iff module init queued any async jobs.  This isn't a full
3272          * solution as it will deadlock the same if module loading from
3273          * async jobs nests more than once; however, due to the various
3274          * constraints, this hack seems to be the best option for now.
3275          * Please refer to the following thread for details.
3276          *
3277          * http://thread.gmane.org/gmane.linux.kernel/1420814
3278          */
3279         if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3280                 async_synchronize_full();
3281 
3282         mutex_lock(&module_mutex);
3283         /* Drop initial reference. */
3284         module_put(mod);
3285         trim_init_extable(mod);
3286 #ifdef CONFIG_KALLSYMS
3287         /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3288         rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3289 #endif
3290         mod_tree_remove_init(mod);
3291         disable_ro_nx(&mod->init_layout);
3292         module_arch_freeing_init(mod);
3293         mod->init_layout.base = NULL;
3294         mod->init_layout.size = 0;
3295         mod->init_layout.ro_size = 0;
3296         mod->init_layout.text_size = 0;
3297         /*
3298          * We want to free module_init, but be aware that kallsyms may be
3299          * walking this with preempt disabled.  In all the failure paths, we
3300          * call synchronize_sched(), but we don't want to slow down the success
3301          * path, so use actual RCU here.
3302          */
3303         call_rcu_sched(&freeinit->rcu, do_free_init);
3304         mutex_unlock(&module_mutex);
3305         wake_up_all(&module_wq);
3306 
3307         return 0;
3308 
3309 fail_free_freeinit:
3310         kfree(freeinit);
3311 fail:
3312         /* Try to protect us from buggy refcounters. */
3313         mod->state = MODULE_STATE_GOING;
3314         synchronize_sched();
3315         module_put(mod);
3316         blocking_notifier_call_chain(&module_notify_list,
3317                                      MODULE_STATE_GOING, mod);
3318         ftrace_release_mod(mod);
3319         free_module(mod);
3320         wake_up_all(&module_wq);
3321         return ret;
3322 }
3323 
3324 static int may_init_module(void)
3325 {
3326         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3327                 return -EPERM;
3328 
3329         return 0;
3330 }
3331 
3332 /*
3333  * We try to place it in the list now to make sure it's unique before
3334  * we dedicate too many resources.  In particular, temporary percpu
3335  * memory exhaustion.
3336  */
3337 static int add_unformed_module(struct module *mod)
3338 {
3339         int err;
3340         struct module *old;
3341 
3342         mod->state = MODULE_STATE_UNFORMED;
3343 
3344 again:
3345         mutex_lock(&module_mutex);
3346         old = find_module_all(mod->name, strlen(mod->name), true);
3347         if (old != NULL) {
3348                 if (old->state == MODULE_STATE_COMING
3349                     || old->state == MODULE_STATE_UNFORMED) {
3350                         /* Wait in case it fails to load. */
3351                         mutex_unlock(&module_mutex);
3352                         err = wait_event_interruptible(module_wq,
3353                                                finished_loading(mod->name));
3354                         if (err)
3355                                 goto out_unlocked;
3356                         goto again;
3357                 }
3358                 err = -EEXIST;
3359                 goto out;
3360         }
3361         mod_update_bounds(mod);
3362         list_add_rcu(&mod->list, &modules);
3363         mod_tree_insert(mod);
3364         err = 0;
3365 
3366 out:
3367         mutex_unlock(&module_mutex);
3368 out_unlocked:
3369         return err;
3370 }
3371 
3372 static int complete_formation(struct module *mod, struct load_info *info)
3373 {
3374         int err;
3375 
3376         mutex_lock(&module_mutex);
3377 
3378         /* Find duplicate symbols (must be called under lock). */
3379         err = verify_export_symbols(mod);
3380         if (err < 0)
3381                 goto out;
3382 
3383         /* This relies on module_mutex for list integrity. */
3384         module_bug_finalize(info->hdr, info->sechdrs, mod);
3385 
3386         /* Set RO and NX regions */
3387         module_enable_ro(mod);
3388         module_enable_nx(mod);
3389 
3390         /* Mark state as coming so strong_try_module_get() ignores us,
3391          * but kallsyms etc. can see us. */
3392         mod->state = MODULE_STATE_COMING;
3393         mutex_unlock(&module_mutex);
3394 
3395         ftrace_module_enable(mod);
3396         blocking_notifier_call_chain(&module_notify_list,
3397                                      MODULE_STATE_COMING, mod);
3398         return 0;
3399 
3400 out:
3401         mutex_unlock(&module_mutex);
3402         return err;
3403 }
3404 
3405 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3406                                    void *arg)
3407 {
3408         struct module *mod = arg;
3409         int ret;
3410 
3411         if (strcmp(param, "async_probe") == 0) {
3412                 mod->async_probe_requested = true;
3413                 return 0;
3414         }
3415 
3416         /* Check for magic 'dyndbg' arg */
3417         ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3418         if (ret != 0)
3419                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3420         return 0;
3421 }
3422 
3423 /* Allocate and load the module: note that size of section 0 is always
3424    zero, and we rely on this for optional sections. */
3425 static int load_module(struct load_info *info, const char __user *uargs,
3426                        int flags)
3427 {
3428         struct module *mod;
3429         long err;
3430         char *after_dashes;
3431 
3432         err = module_sig_check(info);
3433         if (err)
3434                 goto free_copy;
3435 
3436         err = elf_header_check(info);
3437         if (err)
3438                 goto free_copy;
3439 
3440         /* Figure out module layout, and allocate all the memory. */
3441         mod = layout_and_allocate(info, flags);
3442         if (IS_ERR(mod)) {
3443                 err = PTR_ERR(mod);
3444                 goto free_copy;
3445         }
3446 
3447         /* Reserve our place in the list. */
3448         err = add_unformed_module(mod);
3449         if (err)
3450                 goto free_module;
3451 
3452 #ifdef CONFIG_MODULE_SIG
3453         mod->sig_ok = info->sig_ok;
3454         if (!mod->sig_ok) {
3455                 pr_notice_once("%s: module verification failed: signature "
3456                                "and/or required key missing - tainting "
3457                                "kernel\n", mod->name);
3458                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3459         }
3460 #endif
3461 
3462         /* To avoid stressing percpu allocator, do this once we're unique. */
3463         err = percpu_modalloc(mod, info);
3464         if (err)
3465                 goto unlink_mod;
3466 
3467         /* Now module is in final location, initialize linked lists, etc. */
3468         err = module_unload_init(mod);
3469         if (err)
3470                 goto unlink_mod;
3471 
3472         init_param_lock(mod);
3473 
3474         /* Now we've got everything in the final locations, we can
3475          * find optional sections. */
3476         err = find_module_sections(mod, info);
3477         if (err)
3478                 goto free_unload;
3479 
3480         err = check_module_license_and_versions(mod);
3481         if (err)
3482                 goto free_unload;
3483 
3484         /* Set up MODINFO_ATTR fields */
3485         setup_modinfo(mod, info);
3486 
3487         /* Fix up syms, so that st_value is a pointer to location. */
3488         err = simplify_symbols(mod, info);
3489         if (err < 0)
3490                 goto free_modinfo;
3491 
3492         err = apply_relocations(mod, info);
3493         if (err < 0)
3494                 goto free_modinfo;
3495 
3496         err = post_relocation(mod, info);
3497         if (err < 0)
3498                 goto free_modinfo;
3499 
3500         flush_module_icache(mod);
3501 
3502         /* Now copy in args */
3503         mod->args = strndup_user(uargs, ~0UL >> 1);
3504         if (IS_ERR(mod->args)) {
3505                 err = PTR_ERR(mod->args);
3506                 goto free_arch_cleanup;
3507         }
3508 
3509         dynamic_debug_setup(info->debug, info->num_debug);
3510 
3511         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3512         ftrace_module_init(mod);
3513 
3514         /* Finally it's fully formed, ready to start executing. */
3515         err = complete_formation(mod, info);
3516         if (err)
3517                 goto ddebug_cleanup;
3518 
3519         /* Module is ready to execute: parsing args may do that. */
3520         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3521                                   -32768, 32767, mod,
3522                                   unknown_module_param_cb);
3523         if (IS_ERR(after_dashes)) {
3524                 err = PTR_ERR(after_dashes);
3525                 goto bug_cleanup;
3526         } else if (after_dashes) {
3527                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3528                        mod->name, after_dashes);
3529         }
3530 
3531         /* Link in to syfs. */
3532         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3533         if (err < 0)
3534                 goto bug_cleanup;
3535 
3536         /* Get rid of temporary copy. */
3537         free_copy(info);
3538 
3539         /* Done! */
3540         trace_module_load(mod);
3541 
3542         return do_init_module(mod);
3543 
3544  bug_cleanup:
3545         /* module_bug_cleanup needs module_mutex protection */
3546         mutex_lock(&module_mutex);
3547         module_bug_cleanup(mod);
3548         mutex_unlock(&module_mutex);
3549 
3550         blocking_notifier_call_chain(&module_notify_list,
3551                                      MODULE_STATE_GOING, mod);
3552 
3553         /* we can't deallocate the module until we clear memory protection */
3554         module_disable_ro(mod);
3555         module_disable_nx(mod);
3556 
3557  ddebug_cleanup:
3558         dynamic_debug_remove(info->debug);
3559         synchronize_sched();
3560         kfree(mod->args);
3561  free_arch_cleanup:
3562         module_arch_cleanup(mod);
3563  free_modinfo:
3564         free_modinfo(mod);
3565  free_unload:
3566         module_unload_free(mod);
3567  unlink_mod:
3568         mutex_lock(&module_mutex);
3569         /* Unlink carefully: kallsyms could be walking list. */
3570         list_del_rcu(&mod->list);
3571         mod_tree_remove(mod);
3572         wake_up_all(&module_wq);
3573         /* Wait for RCU-sched synchronizing before releasing mod->list. */
3574         synchronize_sched();
3575         mutex_unlock(&module_mutex);
3576  free_module:
3577         /*
3578          * Ftrace needs to clean up what it initialized.
3579          * This does nothing if ftrace_module_init() wasn't called,
3580          * but it must be called outside of module_mutex.
3581          */
3582         ftrace_release_mod(mod);
3583         /* Free lock-classes; relies on the preceding sync_rcu() */
3584         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3585 
3586         module_deallocate(mod, info);
3587  free_copy:
3588         free_copy(info);
3589         return err;
3590 }
3591 
3592 SYSCALL_DEFINE3(init_module, void __user *, umod,
3593                 unsigned long, len, const char __user *, uargs)
3594 {
3595         int err;
3596         struct load_info info = { };
3597 
3598         err = may_init_module();
3599         if (err)
3600                 return err;
3601 
3602         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3603                umod, len, uargs);
3604 
3605         err = copy_module_from_user(umod, len, &info);
3606         if (err)
3607                 return err;
3608 
3609         return load_module(&info, uargs, 0);
3610 }
3611 
3612 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3613 {
3614         int err;
3615         struct load_info info = { };
3616 
3617         err = may_init_module();
3618         if (err)
3619                 return err;
3620 
3621         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3622 
3623         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3624                       |MODULE_INIT_IGNORE_VERMAGIC))
3625                 return -EINVAL;
3626 
3627         err = copy_module_from_fd(fd, &info);
3628         if (err)
3629                 return err;
3630 
3631         return load_module(&info, uargs, flags);
3632 }
3633 
3634 static inline int within(unsigned long addr, void *start, unsigned long size)
3635 {
3636         return ((void *)addr >= start && (void *)addr < start + size);
3637 }
3638 
3639 #ifdef CONFIG_KALLSYMS
3640 /*
3641  * This ignores the intensely annoying "mapping symbols" found
3642  * in ARM ELF files: $a, $t and $d.
3643  */
3644 static inline int is_arm_mapping_symbol(const char *str)
3645 {
3646         if (str[0] == '.' && str[1] == 'L')
3647                 return true;
3648         return str[0] == '$' && strchr("axtd", str[1])
3649                && (str[2] == '\0' || str[2] == '.');
3650 }
3651 
3652 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3653 {
3654         return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3655 }
3656 
3657 static const char *get_ksymbol(struct module *mod,
3658                                unsigned long addr,
3659                                unsigned long *size,
3660                                unsigned long *offset)
3661 {
3662         unsigned int i, best = 0;
3663         unsigned long nextval;
3664         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3665 
3666         /* At worse, next value is at end of module */
3667         if (within_module_init(addr, mod))
3668                 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3669         else
3670                 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3671 
3672         /* Scan for closest preceding symbol, and next symbol. (ELF
3673            starts real symbols at 1). */
3674         for (i = 1; i < kallsyms->num_symtab; i++) {
3675                 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3676                         continue;
3677 
3678                 /* We ignore unnamed symbols: they're uninformative
3679                  * and inserted at a whim. */
3680                 if (*symname(kallsyms, i) == '\0'
3681                     || is_arm_mapping_symbol(symname(kallsyms, i)))
3682                         continue;
3683 
3684                 if (kallsyms->symtab[i].st_value <= addr
3685                     && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3686                         best = i;
3687                 if (kallsyms->symtab[i].st_value > addr
3688                     && kallsyms->symtab[i].st_value < nextval)
3689                         nextval = kallsyms->symtab[i].st_value;
3690         }
3691 
3692         if (!best)
3693                 return NULL;
3694 
3695         if (size)
3696                 *size = nextval - kallsyms->symtab[best].st_value;
3697         if (offset)
3698                 *offset = addr - kallsyms->symtab[best].st_value;
3699         return symname(kallsyms, best);
3700 }
3701 
3702 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3703  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3704 const char *module_address_lookup(unsigned long addr,
3705                             unsigned long *size,
3706                             unsigned long *offset,
3707                             char **modname,
3708                             char *namebuf)
3709 {
3710         const char *ret = NULL;
3711         struct module *mod;
3712 
3713         preempt_disable();
3714         mod = __module_address(addr);
3715         if (mod) {
3716                 if (modname)
3717                         *modname = mod->name;
3718                 ret = get_ksymbol(mod, addr, size, offset);
3719         }
3720         /* Make a copy in here where it's safe */
3721         if (ret) {
3722                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3723                 ret = namebuf;
3724         }
3725         preempt_enable();
3726 
3727         return ret;
3728 }
3729 
3730 int lookup_module_symbol_name(unsigned long addr, char *symname)
3731 {
3732         struct module *mod;
3733 
3734         preempt_disable();
3735         list_for_each_entry_rcu(mod, &modules, list) {
3736                 if (mod->state == MODULE_STATE_UNFORMED)
3737                         continue;
3738                 if (within_module(addr, mod)) {
3739                         const char *sym;
3740 
3741                         sym = get_ksymbol(mod, addr, NULL, NULL);
3742                         if (!sym)
3743                                 goto out;
3744                         strlcpy(symname, sym, KSYM_NAME_LEN);
3745                         preempt_enable();
3746                         return 0;
3747                 }
3748         }
3749 out:
3750         preempt_enable();
3751         return -ERANGE;
3752 }
3753 
3754 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3755                         unsigned long *offset, char *modname, char *name)
3756 {
3757         struct module *mod;
3758 
3759         preempt_disable();
3760         list_for_each_entry_rcu(mod, &modules, list) {
3761                 if (mod->state == MODULE_STATE_UNFORMED)
3762                         continue;
3763                 if (within_module(addr, mod)) {
3764                         const char *sym;
3765 
3766                         sym = get_ksymbol(mod, addr, size, offset);
3767                         if (!sym)
3768                                 goto out;
3769                         if (modname)
3770                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3771                         if (name)
3772                                 strlcpy(name, sym, KSYM_NAME_LEN);
3773                         preempt_enable();
3774                         return 0;
3775                 }
3776         }
3777 out:
3778         preempt_enable();
3779         return -ERANGE;
3780 }
3781 
3782 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3783                         char *name, char *module_name, int *exported)
3784 {
3785         struct module *mod;
3786 
3787         preempt_disable();
3788         list_for_each_entry_rcu(mod, &modules, list) {
3789                 struct mod_kallsyms *kallsyms;
3790 
3791                 if (mod->state == MODULE_STATE_UNFORMED)
3792                         continue;
3793                 kallsyms = rcu_dereference_sched(mod->kallsyms);
3794                 if (symnum < kallsyms->num_symtab) {
3795                         *value = kallsyms->symtab[symnum].st_value;
3796                         *type = kallsyms->symtab[symnum].st_info;
3797                         strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
3798                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3799                         *exported = is_exported(name, *value, mod);
3800                         preempt_enable();
3801                         return 0;
3802                 }
3803                 symnum -= kallsyms->num_symtab;
3804         }
3805         preempt_enable();
3806         return -ERANGE;
3807 }
3808 
3809 static unsigned long mod_find_symname(struct module *mod, const char *name)
3810 {
3811         unsigned int i;
3812         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3813 
3814         for (i = 0; i < kallsyms->num_symtab; i++)
3815                 if (strcmp(name, symname(kallsyms, i)) == 0 &&
3816                     kallsyms->symtab[i].st_info != 'U')
3817                         return kallsyms->symtab[i].st_value;
3818         return 0;
3819 }
3820 
3821 /* Look for this name: can be of form module:name. */
3822 unsigned long module_kallsyms_lookup_name(const char *name)
3823 {
3824         struct module *mod;
3825         char *colon;
3826         unsigned long ret = 0;
3827 
3828         /* Don't lock: we're in enough trouble already. */
3829         preempt_disable();
3830         if ((colon = strchr(name, ':')) != NULL) {
3831                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3832                         ret = mod_find_symname(mod, colon+1);
3833         } else {
3834                 list_for_each_entry_rcu(mod, &modules, list) {
3835                         if (mod->state == MODULE_STATE_UNFORMED)
3836                                 continue;
3837                         if ((ret = mod_find_symname(mod, name)) != 0)
3838                                 break;
3839                 }
3840         }
3841         preempt_enable();
3842         return ret;
3843 }
3844 
3845 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3846                                              struct module *, unsigned long),
3847                                    void *data)
3848 {
3849         struct module *mod;
3850         unsigned int i;
3851         int ret;
3852 
3853         module_assert_mutex();
3854 
3855         list_for_each_entry(mod, &modules, list) {
3856                 /* We hold module_mutex: no need for rcu_dereference_sched */
3857                 struct mod_kallsyms *kallsyms = mod->kallsyms;
3858 
3859                 if (mod->state == MODULE_STATE_UNFORMED)
3860                         continue;
3861                 for (i = 0; i < kallsyms->num_symtab; i++) {
3862                         ret = fn(data, symname(kallsyms, i),
3863                                  mod, kallsyms->symtab[i].st_value);
3864                         if (ret != 0)
3865                                 return ret;
3866                 }
3867         }
3868         return 0;
3869 }
3870 #endif /* CONFIG_KALLSYMS */
3871 
3872 static char *module_flags(struct module *mod, char *buf)
3873 {
3874         int bx = 0;
3875 
3876         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3877         if (mod->taints ||
3878             mod->state == MODULE_STATE_GOING ||
3879             mod->state == MODULE_STATE_COMING) {
3880                 buf[bx++] = '(';
3881                 bx += module_flags_taint(mod, buf + bx);
3882                 /* Show a - for module-is-being-unloaded */
3883                 if (mod->state == MODULE_STATE_GOING)
3884                         buf[bx++] = '-';
3885                 /* Show a + for module-is-being-loaded */
3886                 if (mod->state == MODULE_STATE_COMING)
3887                         buf[bx++] = '+';
3888                 buf[bx++] = ')';
3889         }
3890         buf[bx] = '\0';
3891 
3892         return buf;
3893 }
3894 
3895 #ifdef CONFIG_PROC_FS
3896 /* Called by the /proc file system to return a list of modules. */
3897 static void *m_start(struct seq_file *m, loff_t *pos)
3898 {
3899         mutex_lock(&module_mutex);
3900         return seq_list_start(&modules, *pos);
3901 }
3902 
3903 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3904 {
3905         return seq_list_next(p, &modules, pos);
3906 }
3907 
3908 static void m_stop(struct seq_file *m, void *p)
3909 {
3910         mutex_unlock(&module_mutex);
3911 }
3912 
3913 static int m_show(struct seq_file *m, void *p)
3914 {
3915         struct module *mod = list_entry(p, struct module, list);
3916         char buf[8];
3917 
3918         /* We always ignore unformed modules. */
3919         if (mod->state == MODULE_STATE_UNFORMED)
3920                 return 0;
3921 
3922         seq_printf(m, "%s %u",
3923                    mod->name, mod->init_layout.size + mod->core_layout.size);
3924         print_unload_info(m, mod);
3925 
3926         /* Informative for users. */
3927         seq_printf(m, " %s",
3928                    mod->state == MODULE_STATE_GOING ? "Unloading" :
3929                    mod->state == MODULE_STATE_COMING ? "Loading" :
3930                    "Live");
3931         /* Used by oprofile and other similar tools. */
3932         seq_printf(m, " 0x%pK", mod->core_layout.base);
3933 
3934         /* Taints info */
3935         if (mod->taints)
3936                 seq_printf(m, " %s", module_flags(mod, buf));
3937 
3938         seq_puts(m, "\n");
3939         return 0;
3940 }
3941 
3942 /* Format: modulename size refcount deps address
3943 
3944    Where refcount is a number or -, and deps is a comma-separated list
3945    of depends or -.
3946 */
3947 static const struct seq_operations modules_op = {
3948         .start  = m_start,
3949         .next   = m_next,
3950         .stop   = m_stop,
3951         .show   = m_show
3952 };
3953 
3954 static int modules_open(struct inode *inode, struct file *file)
3955 {
3956         return seq_open(file, &modules_op);
3957 }
3958 
3959 static const struct file_operations proc_modules_operations = {
3960         .open           = modules_open,
3961         .read           = seq_read,
3962         .llseek         = seq_lseek,
3963         .release        = seq_release,
3964 };
3965 
3966 static int __init proc_modules_init(void)
3967 {
3968         proc_create("modules", 0, NULL, &proc_modules_operations);
3969         return 0;
3970 }
3971 module_init(proc_modules_init);
3972 #endif
3973 
3974 /* Given an address, look for it in the module exception tables. */
3975 const struct exception_table_entry *search_module_extables(unsigned long addr)
3976 {
3977         const struct exception_table_entry *e = NULL;
3978         struct module *mod;
3979 
3980         preempt_disable();
3981         list_for_each_entry_rcu(mod, &modules, list) {
3982                 if (mod->state == MODULE_STATE_UNFORMED)
3983                         continue;
3984                 if (mod->num_exentries == 0)
3985                         continue;
3986 
3987                 e = search_extable(mod->extable,
3988                                    mod->extable + mod->num_exentries - 1,
3989                                    addr);
3990                 if (e)
3991                         break;
3992         }
3993         preempt_enable();
3994 
3995         /* Now, if we found one, we are running inside it now, hence
3996            we cannot unload the module, hence no refcnt needed. */
3997         return e;
3998 }
3999 
4000 /*
4001  * is_module_address - is this address inside a module?
4002  * @addr: the address to check.
4003  *
4004  * See is_module_text_address() if you simply want to see if the address
4005  * is code (not data).
4006  */
4007 bool is_module_address(unsigned long addr)
4008 {
4009         bool ret;
4010 
4011         preempt_disable();
4012         ret = __module_address(addr) != NULL;
4013         preempt_enable();
4014 
4015         return ret;
4016 }
4017 
4018 /*
4019  * __module_address - get the module which contains an address.
4020  * @addr: the address.
4021  *
4022  * Must be called with preempt disabled or module mutex held so that
4023  * module doesn't get freed during this.
4024  */
4025 struct module *__module_address(unsigned long addr)
4026 {
4027         struct module *mod;
4028 
4029         if (addr < module_addr_min || addr > module_addr_max)
4030                 return NULL;
4031 
4032         module_assert_mutex_or_preempt();
4033 
4034         mod = mod_find(addr);
4035         if (mod) {
4036                 BUG_ON(!within_module(addr, mod));
4037                 if (mod->state == MODULE_STATE_UNFORMED)
4038                         mod = NULL;
4039         }
4040         return mod;
4041 }
4042 EXPORT_SYMBOL_GPL(__module_address);
4043 
4044 /*
4045  * is_module_text_address - is this address inside module code?
4046  * @addr: the address to check.
4047  *
4048  * See is_module_address() if you simply want to see if the address is
4049  * anywhere in a module.  See kernel_text_address() for testing if an
4050  * address corresponds to kernel or module code.
4051  */
4052 bool is_module_text_address(unsigned long addr)
4053 {
4054         bool ret;
4055 
4056         preempt_disable();
4057         ret = __module_text_address(addr) != NULL;
4058         preempt_enable();
4059 
4060         return ret;
4061 }
4062 
4063 /*
4064  * __module_text_address - get the module whose code contains an address.
4065  * @addr: the address.
4066  *
4067  * Must be called with preempt disabled or module mutex held so that
4068  * module doesn't get freed during this.
4069  */
4070 struct module *__module_text_address(unsigned long addr)
4071 {
4072         struct module *mod = __module_address(addr);
4073         if (mod) {
4074                 /* Make sure it's within the text section. */
4075                 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4076                     && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4077                         mod = NULL;
4078         }
4079         return mod;
4080 }
4081 EXPORT_SYMBOL_GPL(__module_text_address);
4082 
4083 /* Don't grab lock, we're oopsing. */
4084 void print_modules(void)
4085 {
4086         struct module *mod;
4087         char buf[8];
4088 
4089         printk(KERN_DEFAULT "Modules linked in:");
4090         /* Most callers should already have preempt disabled, but make sure */
4091         preempt_disable();
4092         list_for_each_entry_rcu(mod, &modules, list) {
4093                 if (mod->state == MODULE_STATE_UNFORMED)
4094                         continue;
4095                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4096         }
4097         preempt_enable();
4098         if (last_unloaded_module[0])
4099                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4100         pr_cont("\n");
4101 }
4102 
4103 #ifdef CONFIG_MODVERSIONS
4104 /* Generate the signature for all relevant module structures here.
4105  * If these change, we don't want to try to parse the module. */
4106 void module_layout(struct module *mod,
4107                    struct modversion_info *ver,
4108                    struct kernel_param *kp,
4109                    struct kernel_symbol *ks,
4110                    struct tracepoint * const *tp)
4111 {
4112 }
4113 EXPORT_SYMBOL(module_layout);
4114 #endif
4115 

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