Version:  2.0.40 2.2.26 2.4.37 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 4.6

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

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