Version:  2.0.40 2.2.26 2.4.37 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2

Linux/kernel/module.c

  1 /*
  2    Copyright (C) 2002 Richard Henderson
  3    Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
  4 
  5     This program is free software; you can redistribute it and/or modify
  6     it under the terms of the GNU General Public License as published by
  7     the Free Software Foundation; either version 2 of the License, or
  8     (at your option) any later version.
  9 
 10     This program is distributed in the hope that it will be useful,
 11     but WITHOUT ANY WARRANTY; without even the implied warranty of
 12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13     GNU General Public License for more details.
 14 
 15     You should have received a copy of the GNU General Public License
 16     along with this program; if not, write to the Free Software
 17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 18 */
 19 #include <linux/export.h>
 20 #include <linux/moduleloader.h>
 21 #include <linux/trace_events.h>
 22 #include <linux/init.h>
 23 #include <linux/kallsyms.h>
 24 #include <linux/file.h>
 25 #include <linux/fs.h>
 26 #include <linux/sysfs.h>
 27 #include <linux/kernel.h>
 28 #include <linux/slab.h>
 29 #include <linux/vmalloc.h>
 30 #include <linux/elf.h>
 31 #include <linux/proc_fs.h>
 32 #include <linux/security.h>
 33 #include <linux/seq_file.h>
 34 #include <linux/syscalls.h>
 35 #include <linux/fcntl.h>
 36 #include <linux/rcupdate.h>
 37 #include <linux/capability.h>
 38 #include <linux/cpu.h>
 39 #include <linux/moduleparam.h>
 40 #include <linux/errno.h>
 41 #include <linux/err.h>
 42 #include <linux/vermagic.h>
 43 #include <linux/notifier.h>
 44 #include <linux/sched.h>
 45 #include <linux/device.h>
 46 #include <linux/string.h>
 47 #include <linux/mutex.h>
 48 #include <linux/rculist.h>
 49 #include <asm/uaccess.h>
 50 #include <asm/cacheflush.h>
 51 #include <asm/mmu_context.h>
 52 #include <linux/license.h>
 53 #include <asm/sections.h>
 54 #include <linux/tracepoint.h>
 55 #include <linux/ftrace.h>
 56 #include <linux/async.h>
 57 #include <linux/percpu.h>
 58 #include <linux/kmemleak.h>
 59 #include <linux/jump_label.h>
 60 #include <linux/pfn.h>
 61 #include <linux/bsearch.h>
 62 #include <uapi/linux/module.h>
 63 #include "module-internal.h"
 64 
 65 #define CREATE_TRACE_POINTS
 66 #include <trace/events/module.h>
 67 
 68 #ifndef ARCH_SHF_SMALL
 69 #define ARCH_SHF_SMALL 0
 70 #endif
 71 
 72 /*
 73  * Modules' sections will be aligned on page boundaries
 74  * to ensure complete separation of code and data, but
 75  * only when CONFIG_DEBUG_SET_MODULE_RONX=y
 76  */
 77 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 78 # define debug_align(X) ALIGN(X, PAGE_SIZE)
 79 #else
 80 # define debug_align(X) (X)
 81 #endif
 82 
 83 /*
 84  * Given BASE and SIZE this macro calculates the number of pages the
 85  * memory regions occupies
 86  */
 87 #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?         \
 88                 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
 89                          PFN_DOWN((unsigned long)BASE) + 1)     \
 90                 : (0UL))
 91 
 92 /* If this is set, the section belongs in the init part of the module */
 93 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
 94 
 95 /*
 96  * Mutex protects:
 97  * 1) List of modules (also safely readable with preempt_disable),
 98  * 2) module_use links,
 99  * 3) module_addr_min/module_addr_max.
100  * (delete and add uses RCU list operations). */
101 DEFINE_MUTEX(module_mutex);
102 EXPORT_SYMBOL_GPL(module_mutex);
103 static LIST_HEAD(modules);
104 
105 #ifdef CONFIG_MODULES_TREE_LOOKUP
106 
107 /*
108  * Use a latched RB-tree for __module_address(); this allows us to use
109  * RCU-sched lookups of the address from any context.
110  *
111  * Because modules have two address ranges: init and core, we need two
112  * latch_tree_nodes entries. Therefore we need the back-pointer from
113  * mod_tree_node.
114  *
115  * Because init ranges are short lived we mark them unlikely and have placed
116  * them outside the critical cacheline in struct module.
117  *
118  * This is conditional on PERF_EVENTS || TRACING because those can really hit
119  * __module_address() hard by doing a lot of stack unwinding; potentially from
120  * NMI context.
121  */
122 
123 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
124 {
125         struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node);
126         struct module *mod = mtn->mod;
127 
128         if (unlikely(mtn == &mod->mtn_init))
129                 return (unsigned long)mod->module_init;
130 
131         return (unsigned long)mod->module_core;
132 }
133 
134 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
135 {
136         struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node);
137         struct module *mod = mtn->mod;
138 
139         if (unlikely(mtn == &mod->mtn_init))
140                 return (unsigned long)mod->init_size;
141 
142         return (unsigned long)mod->core_size;
143 }
144 
145 static __always_inline bool
146 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
147 {
148         return __mod_tree_val(a) < __mod_tree_val(b);
149 }
150 
151 static __always_inline int
152 mod_tree_comp(void *key, struct latch_tree_node *n)
153 {
154         unsigned long val = (unsigned long)key;
155         unsigned long start, end;
156 
157         start = __mod_tree_val(n);
158         if (val < start)
159                 return -1;
160 
161         end = start + __mod_tree_size(n);
162         if (val >= end)
163                 return 1;
164 
165         return 0;
166 }
167 
168 static const struct latch_tree_ops mod_tree_ops = {
169         .less = mod_tree_less,
170         .comp = mod_tree_comp,
171 };
172 
173 static struct mod_tree_root {
174         struct latch_tree_root root;
175         unsigned long addr_min;
176         unsigned long addr_max;
177 } mod_tree __cacheline_aligned = {
178         .addr_min = -1UL,
179 };
180 
181 #define module_addr_min mod_tree.addr_min
182 #define module_addr_max mod_tree.addr_max
183 
184 static noinline void __mod_tree_insert(struct mod_tree_node *node)
185 {
186         latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
187 }
188 
189 static void __mod_tree_remove(struct mod_tree_node *node)
190 {
191         latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
192 }
193 
194 /*
195  * These modifications: insert, remove_init and remove; are serialized by the
196  * module_mutex.
197  */
198 static void mod_tree_insert(struct module *mod)
199 {
200         mod->mtn_core.mod = mod;
201         mod->mtn_init.mod = mod;
202 
203         __mod_tree_insert(&mod->mtn_core);
204         if (mod->init_size)
205                 __mod_tree_insert(&mod->mtn_init);
206 }
207 
208 static void mod_tree_remove_init(struct module *mod)
209 {
210         if (mod->init_size)
211                 __mod_tree_remove(&mod->mtn_init);
212 }
213 
214 static void mod_tree_remove(struct module *mod)
215 {
216         __mod_tree_remove(&mod->mtn_core);
217         mod_tree_remove_init(mod);
218 }
219 
220 static struct module *mod_find(unsigned long addr)
221 {
222         struct latch_tree_node *ltn;
223 
224         ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
225         if (!ltn)
226                 return NULL;
227 
228         return container_of(ltn, struct mod_tree_node, node)->mod;
229 }
230 
231 #else /* MODULES_TREE_LOOKUP */
232 
233 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
234 
235 static void mod_tree_insert(struct module *mod) { }
236 static void mod_tree_remove_init(struct module *mod) { }
237 static void mod_tree_remove(struct module *mod) { }
238 
239 static struct module *mod_find(unsigned long addr)
240 {
241         struct module *mod;
242 
243         list_for_each_entry_rcu(mod, &modules, list) {
244                 if (within_module(addr, mod))
245                         return mod;
246         }
247 
248         return NULL;
249 }
250 
251 #endif /* MODULES_TREE_LOOKUP */
252 
253 /*
254  * Bounds of module text, for speeding up __module_address.
255  * Protected by module_mutex.
256  */
257 static void __mod_update_bounds(void *base, unsigned int size)
258 {
259         unsigned long min = (unsigned long)base;
260         unsigned long max = min + size;
261 
262         if (min < module_addr_min)
263                 module_addr_min = min;
264         if (max > module_addr_max)
265                 module_addr_max = max;
266 }
267 
268 static void mod_update_bounds(struct module *mod)
269 {
270         __mod_update_bounds(mod->module_core, mod->core_size);
271         if (mod->init_size)
272                 __mod_update_bounds(mod->module_init, mod->init_size);
273 }
274 
275 #ifdef CONFIG_KGDB_KDB
276 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
277 #endif /* CONFIG_KGDB_KDB */
278 
279 static void module_assert_mutex(void)
280 {
281         lockdep_assert_held(&module_mutex);
282 }
283 
284 static void module_assert_mutex_or_preempt(void)
285 {
286 #ifdef CONFIG_LOCKDEP
287         if (unlikely(!debug_locks))
288                 return;
289 
290         WARN_ON(!rcu_read_lock_sched_held() &&
291                 !lockdep_is_held(&module_mutex));
292 #endif
293 }
294 
295 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
296 #ifndef CONFIG_MODULE_SIG_FORCE
297 module_param(sig_enforce, bool_enable_only, 0644);
298 #endif /* !CONFIG_MODULE_SIG_FORCE */
299 
300 /* Block module loading/unloading? */
301 int modules_disabled = 0;
302 core_param(nomodule, modules_disabled, bint, 0);
303 
304 /* Waiting for a module to finish initializing? */
305 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
306 
307 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
308 
309 int register_module_notifier(struct notifier_block *nb)
310 {
311         return blocking_notifier_chain_register(&module_notify_list, nb);
312 }
313 EXPORT_SYMBOL(register_module_notifier);
314 
315 int unregister_module_notifier(struct notifier_block *nb)
316 {
317         return blocking_notifier_chain_unregister(&module_notify_list, nb);
318 }
319 EXPORT_SYMBOL(unregister_module_notifier);
320 
321 struct load_info {
322         Elf_Ehdr *hdr;
323         unsigned long len;
324         Elf_Shdr *sechdrs;
325         char *secstrings, *strtab;
326         unsigned long symoffs, stroffs;
327         struct _ddebug *debug;
328         unsigned int num_debug;
329         bool sig_ok;
330         struct {
331                 unsigned int sym, str, mod, vers, info, pcpu;
332         } index;
333 };
334 
335 /* We require a truly strong try_module_get(): 0 means failure due to
336    ongoing or failed initialization etc. */
337 static inline int strong_try_module_get(struct module *mod)
338 {
339         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
340         if (mod && mod->state == MODULE_STATE_COMING)
341                 return -EBUSY;
342         if (try_module_get(mod))
343                 return 0;
344         else
345                 return -ENOENT;
346 }
347 
348 static inline void add_taint_module(struct module *mod, unsigned flag,
349                                     enum lockdep_ok lockdep_ok)
350 {
351         add_taint(flag, lockdep_ok);
352         mod->taints |= (1U << flag);
353 }
354 
355 /*
356  * A thread that wants to hold a reference to a module only while it
357  * is running can call this to safely exit.  nfsd and lockd use this.
358  */
359 void __module_put_and_exit(struct module *mod, long code)
360 {
361         module_put(mod);
362         do_exit(code);
363 }
364 EXPORT_SYMBOL(__module_put_and_exit);
365 
366 /* Find a module section: 0 means not found. */
367 static unsigned int find_sec(const struct load_info *info, const char *name)
368 {
369         unsigned int i;
370 
371         for (i = 1; i < info->hdr->e_shnum; i++) {
372                 Elf_Shdr *shdr = &info->sechdrs[i];
373                 /* Alloc bit cleared means "ignore it." */
374                 if ((shdr->sh_flags & SHF_ALLOC)
375                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
376                         return i;
377         }
378         return 0;
379 }
380 
381 /* Find a module section, or NULL. */
382 static void *section_addr(const struct load_info *info, const char *name)
383 {
384         /* Section 0 has sh_addr 0. */
385         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
386 }
387 
388 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
389 static void *section_objs(const struct load_info *info,
390                           const char *name,
391                           size_t object_size,
392                           unsigned int *num)
393 {
394         unsigned int sec = find_sec(info, name);
395 
396         /* Section 0 has sh_addr 0 and sh_size 0. */
397         *num = info->sechdrs[sec].sh_size / object_size;
398         return (void *)info->sechdrs[sec].sh_addr;
399 }
400 
401 /* Provided by the linker */
402 extern const struct kernel_symbol __start___ksymtab[];
403 extern const struct kernel_symbol __stop___ksymtab[];
404 extern const struct kernel_symbol __start___ksymtab_gpl[];
405 extern const struct kernel_symbol __stop___ksymtab_gpl[];
406 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
407 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
408 extern const unsigned long __start___kcrctab[];
409 extern const unsigned long __start___kcrctab_gpl[];
410 extern const unsigned long __start___kcrctab_gpl_future[];
411 #ifdef CONFIG_UNUSED_SYMBOLS
412 extern const struct kernel_symbol __start___ksymtab_unused[];
413 extern const struct kernel_symbol __stop___ksymtab_unused[];
414 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
415 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
416 extern const unsigned long __start___kcrctab_unused[];
417 extern const unsigned long __start___kcrctab_unused_gpl[];
418 #endif
419 
420 #ifndef CONFIG_MODVERSIONS
421 #define symversion(base, idx) NULL
422 #else
423 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
424 #endif
425 
426 static bool each_symbol_in_section(const struct symsearch *arr,
427                                    unsigned int arrsize,
428                                    struct module *owner,
429                                    bool (*fn)(const struct symsearch *syms,
430                                               struct module *owner,
431                                               void *data),
432                                    void *data)
433 {
434         unsigned int j;
435 
436         for (j = 0; j < arrsize; j++) {
437                 if (fn(&arr[j], owner, data))
438                         return true;
439         }
440 
441         return false;
442 }
443 
444 /* Returns true as soon as fn returns true, otherwise false. */
445 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
446                                     struct module *owner,
447                                     void *data),
448                          void *data)
449 {
450         struct module *mod;
451         static const struct symsearch arr[] = {
452                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
453                   NOT_GPL_ONLY, false },
454                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
455                   __start___kcrctab_gpl,
456                   GPL_ONLY, false },
457                 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
458                   __start___kcrctab_gpl_future,
459                   WILL_BE_GPL_ONLY, false },
460 #ifdef CONFIG_UNUSED_SYMBOLS
461                 { __start___ksymtab_unused, __stop___ksymtab_unused,
462                   __start___kcrctab_unused,
463                   NOT_GPL_ONLY, true },
464                 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
465                   __start___kcrctab_unused_gpl,
466                   GPL_ONLY, true },
467 #endif
468         };
469 
470         module_assert_mutex_or_preempt();
471 
472         if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
473                 return true;
474 
475         list_for_each_entry_rcu(mod, &modules, list) {
476                 struct symsearch arr[] = {
477                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
478                           NOT_GPL_ONLY, false },
479                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
480                           mod->gpl_crcs,
481                           GPL_ONLY, false },
482                         { mod->gpl_future_syms,
483                           mod->gpl_future_syms + mod->num_gpl_future_syms,
484                           mod->gpl_future_crcs,
485                           WILL_BE_GPL_ONLY, false },
486 #ifdef CONFIG_UNUSED_SYMBOLS
487                         { mod->unused_syms,
488                           mod->unused_syms + mod->num_unused_syms,
489                           mod->unused_crcs,
490                           NOT_GPL_ONLY, true },
491                         { mod->unused_gpl_syms,
492                           mod->unused_gpl_syms + mod->num_unused_gpl_syms,
493                           mod->unused_gpl_crcs,
494                           GPL_ONLY, true },
495 #endif
496                 };
497 
498                 if (mod->state == MODULE_STATE_UNFORMED)
499                         continue;
500 
501                 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
502                         return true;
503         }
504         return false;
505 }
506 EXPORT_SYMBOL_GPL(each_symbol_section);
507 
508 struct find_symbol_arg {
509         /* Input */
510         const char *name;
511         bool gplok;
512         bool warn;
513 
514         /* Output */
515         struct module *owner;
516         const unsigned long *crc;
517         const struct kernel_symbol *sym;
518 };
519 
520 static bool check_symbol(const struct symsearch *syms,
521                                  struct module *owner,
522                                  unsigned int symnum, void *data)
523 {
524         struct find_symbol_arg *fsa = data;
525 
526         if (!fsa->gplok) {
527                 if (syms->licence == GPL_ONLY)
528                         return false;
529                 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
530                         pr_warn("Symbol %s is being used by a non-GPL module, "
531                                 "which will not be allowed in the future\n",
532                                 fsa->name);
533                 }
534         }
535 
536 #ifdef CONFIG_UNUSED_SYMBOLS
537         if (syms->unused && fsa->warn) {
538                 pr_warn("Symbol %s is marked as UNUSED, however this module is "
539                         "using it.\n", fsa->name);
540                 pr_warn("This symbol will go away in the future.\n");
541                 pr_warn("Please evaluate if this is the right api to use and "
542                         "if it really is, submit a report to the linux kernel "
543                         "mailing list together with submitting your code for "
544                         "inclusion.\n");
545         }
546 #endif
547 
548         fsa->owner = owner;
549         fsa->crc = symversion(syms->crcs, symnum);
550         fsa->sym = &syms->start[symnum];
551         return true;
552 }
553 
554 static int cmp_name(const void *va, const void *vb)
555 {
556         const char *a;
557         const struct kernel_symbol *b;
558         a = va; b = vb;
559         return strcmp(a, b->name);
560 }
561 
562 static bool find_symbol_in_section(const struct symsearch *syms,
563                                    struct module *owner,
564                                    void *data)
565 {
566         struct find_symbol_arg *fsa = data;
567         struct kernel_symbol *sym;
568 
569         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
570                         sizeof(struct kernel_symbol), cmp_name);
571 
572         if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
573                 return true;
574 
575         return false;
576 }
577 
578 /* Find a symbol and return it, along with, (optional) crc and
579  * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
580 const struct kernel_symbol *find_symbol(const char *name,
581                                         struct module **owner,
582                                         const unsigned long **crc,
583                                         bool gplok,
584                                         bool warn)
585 {
586         struct find_symbol_arg fsa;
587 
588         fsa.name = name;
589         fsa.gplok = gplok;
590         fsa.warn = warn;
591 
592         if (each_symbol_section(find_symbol_in_section, &fsa)) {
593                 if (owner)
594                         *owner = fsa.owner;
595                 if (crc)
596                         *crc = fsa.crc;
597                 return fsa.sym;
598         }
599 
600         pr_debug("Failed to find symbol %s\n", name);
601         return NULL;
602 }
603 EXPORT_SYMBOL_GPL(find_symbol);
604 
605 /*
606  * Search for module by name: must hold module_mutex (or preempt disabled
607  * for read-only access).
608  */
609 static struct module *find_module_all(const char *name, size_t len,
610                                       bool even_unformed)
611 {
612         struct module *mod;
613 
614         module_assert_mutex_or_preempt();
615 
616         list_for_each_entry(mod, &modules, list) {
617                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
618                         continue;
619                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
620                         return mod;
621         }
622         return NULL;
623 }
624 
625 struct module *find_module(const char *name)
626 {
627         module_assert_mutex();
628         return find_module_all(name, strlen(name), false);
629 }
630 EXPORT_SYMBOL_GPL(find_module);
631 
632 #ifdef CONFIG_SMP
633 
634 static inline void __percpu *mod_percpu(struct module *mod)
635 {
636         return mod->percpu;
637 }
638 
639 static int percpu_modalloc(struct module *mod, struct load_info *info)
640 {
641         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
642         unsigned long align = pcpusec->sh_addralign;
643 
644         if (!pcpusec->sh_size)
645                 return 0;
646 
647         if (align > PAGE_SIZE) {
648                 pr_warn("%s: per-cpu alignment %li > %li\n",
649                         mod->name, align, PAGE_SIZE);
650                 align = PAGE_SIZE;
651         }
652 
653         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
654         if (!mod->percpu) {
655                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
656                         mod->name, (unsigned long)pcpusec->sh_size);
657                 return -ENOMEM;
658         }
659         mod->percpu_size = pcpusec->sh_size;
660         return 0;
661 }
662 
663 static void percpu_modfree(struct module *mod)
664 {
665         free_percpu(mod->percpu);
666 }
667 
668 static unsigned int find_pcpusec(struct load_info *info)
669 {
670         return find_sec(info, ".data..percpu");
671 }
672 
673 static void percpu_modcopy(struct module *mod,
674                            const void *from, unsigned long size)
675 {
676         int cpu;
677 
678         for_each_possible_cpu(cpu)
679                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
680 }
681 
682 /**
683  * is_module_percpu_address - test whether address is from module static percpu
684  * @addr: address to test
685  *
686  * Test whether @addr belongs to module static percpu area.
687  *
688  * RETURNS:
689  * %true if @addr is from module static percpu area
690  */
691 bool is_module_percpu_address(unsigned long addr)
692 {
693         struct module *mod;
694         unsigned int cpu;
695 
696         preempt_disable();
697 
698         list_for_each_entry_rcu(mod, &modules, list) {
699                 if (mod->state == MODULE_STATE_UNFORMED)
700                         continue;
701                 if (!mod->percpu_size)
702                         continue;
703                 for_each_possible_cpu(cpu) {
704                         void *start = per_cpu_ptr(mod->percpu, cpu);
705 
706                         if ((void *)addr >= start &&
707                             (void *)addr < start + mod->percpu_size) {
708                                 preempt_enable();
709                                 return true;
710                         }
711                 }
712         }
713 
714         preempt_enable();
715         return false;
716 }
717 
718 #else /* ... !CONFIG_SMP */
719 
720 static inline void __percpu *mod_percpu(struct module *mod)
721 {
722         return NULL;
723 }
724 static int percpu_modalloc(struct module *mod, struct load_info *info)
725 {
726         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
727         if (info->sechdrs[info->index.pcpu].sh_size != 0)
728                 return -ENOMEM;
729         return 0;
730 }
731 static inline void percpu_modfree(struct module *mod)
732 {
733 }
734 static unsigned int find_pcpusec(struct load_info *info)
735 {
736         return 0;
737 }
738 static inline void percpu_modcopy(struct module *mod,
739                                   const void *from, unsigned long size)
740 {
741         /* pcpusec should be 0, and size of that section should be 0. */
742         BUG_ON(size != 0);
743 }
744 bool is_module_percpu_address(unsigned long addr)
745 {
746         return false;
747 }
748 
749 #endif /* CONFIG_SMP */
750 
751 #define MODINFO_ATTR(field)     \
752 static void setup_modinfo_##field(struct module *mod, const char *s)  \
753 {                                                                     \
754         mod->field = kstrdup(s, GFP_KERNEL);                          \
755 }                                                                     \
756 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
757                         struct module_kobject *mk, char *buffer)      \
758 {                                                                     \
759         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
760 }                                                                     \
761 static int modinfo_##field##_exists(struct module *mod)               \
762 {                                                                     \
763         return mod->field != NULL;                                    \
764 }                                                                     \
765 static void free_modinfo_##field(struct module *mod)                  \
766 {                                                                     \
767         kfree(mod->field);                                            \
768         mod->field = NULL;                                            \
769 }                                                                     \
770 static struct module_attribute modinfo_##field = {                    \
771         .attr = { .name = __stringify(field), .mode = 0444 },         \
772         .show = show_modinfo_##field,                                 \
773         .setup = setup_modinfo_##field,                               \
774         .test = modinfo_##field##_exists,                             \
775         .free = free_modinfo_##field,                                 \
776 };
777 
778 MODINFO_ATTR(version);
779 MODINFO_ATTR(srcversion);
780 
781 static char last_unloaded_module[MODULE_NAME_LEN+1];
782 
783 #ifdef CONFIG_MODULE_UNLOAD
784 
785 EXPORT_TRACEPOINT_SYMBOL(module_get);
786 
787 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
788 #define MODULE_REF_BASE 1
789 
790 /* Init the unload section of the module. */
791 static int module_unload_init(struct module *mod)
792 {
793         /*
794          * Initialize reference counter to MODULE_REF_BASE.
795          * refcnt == 0 means module is going.
796          */
797         atomic_set(&mod->refcnt, MODULE_REF_BASE);
798 
799         INIT_LIST_HEAD(&mod->source_list);
800         INIT_LIST_HEAD(&mod->target_list);
801 
802         /* Hold reference count during initialization. */
803         atomic_inc(&mod->refcnt);
804 
805         return 0;
806 }
807 
808 /* Does a already use b? */
809 static int already_uses(struct module *a, struct module *b)
810 {
811         struct module_use *use;
812 
813         list_for_each_entry(use, &b->source_list, source_list) {
814                 if (use->source == a) {
815                         pr_debug("%s uses %s!\n", a->name, b->name);
816                         return 1;
817                 }
818         }
819         pr_debug("%s does not use %s!\n", a->name, b->name);
820         return 0;
821 }
822 
823 /*
824  * Module a uses b
825  *  - we add 'a' as a "source", 'b' as a "target" of module use
826  *  - the module_use is added to the list of 'b' sources (so
827  *    'b' can walk the list to see who sourced them), and of 'a'
828  *    targets (so 'a' can see what modules it targets).
829  */
830 static int add_module_usage(struct module *a, struct module *b)
831 {
832         struct module_use *use;
833 
834         pr_debug("Allocating new usage for %s.\n", a->name);
835         use = kmalloc(sizeof(*use), GFP_ATOMIC);
836         if (!use) {
837                 pr_warn("%s: out of memory loading\n", a->name);
838                 return -ENOMEM;
839         }
840 
841         use->source = a;
842         use->target = b;
843         list_add(&use->source_list, &b->source_list);
844         list_add(&use->target_list, &a->target_list);
845         return 0;
846 }
847 
848 /* Module a uses b: caller needs module_mutex() */
849 int ref_module(struct module *a, struct module *b)
850 {
851         int err;
852 
853         if (b == NULL || already_uses(a, b))
854                 return 0;
855 
856         /* If module isn't available, we fail. */
857         err = strong_try_module_get(b);
858         if (err)
859                 return err;
860 
861         err = add_module_usage(a, b);
862         if (err) {
863                 module_put(b);
864                 return err;
865         }
866         return 0;
867 }
868 EXPORT_SYMBOL_GPL(ref_module);
869 
870 /* Clear the unload stuff of the module. */
871 static void module_unload_free(struct module *mod)
872 {
873         struct module_use *use, *tmp;
874 
875         mutex_lock(&module_mutex);
876         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
877                 struct module *i = use->target;
878                 pr_debug("%s unusing %s\n", mod->name, i->name);
879                 module_put(i);
880                 list_del(&use->source_list);
881                 list_del(&use->target_list);
882                 kfree(use);
883         }
884         mutex_unlock(&module_mutex);
885 }
886 
887 #ifdef CONFIG_MODULE_FORCE_UNLOAD
888 static inline int try_force_unload(unsigned int flags)
889 {
890         int ret = (flags & O_TRUNC);
891         if (ret)
892                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
893         return ret;
894 }
895 #else
896 static inline int try_force_unload(unsigned int flags)
897 {
898         return 0;
899 }
900 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
901 
902 /* Try to release refcount of module, 0 means success. */
903 static int try_release_module_ref(struct module *mod)
904 {
905         int ret;
906 
907         /* Try to decrement refcnt which we set at loading */
908         ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
909         BUG_ON(ret < 0);
910         if (ret)
911                 /* Someone can put this right now, recover with checking */
912                 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
913 
914         return ret;
915 }
916 
917 static int try_stop_module(struct module *mod, int flags, int *forced)
918 {
919         /* If it's not unused, quit unless we're forcing. */
920         if (try_release_module_ref(mod) != 0) {
921                 *forced = try_force_unload(flags);
922                 if (!(*forced))
923                         return -EWOULDBLOCK;
924         }
925 
926         /* Mark it as dying. */
927         mod->state = MODULE_STATE_GOING;
928 
929         return 0;
930 }
931 
932 /**
933  * module_refcount - return the refcount or -1 if unloading
934  *
935  * @mod:        the module we're checking
936  *
937  * Returns:
938  *      -1 if the module is in the process of unloading
939  *      otherwise the number of references in the kernel to the module
940  */
941 int module_refcount(struct module *mod)
942 {
943         return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
944 }
945 EXPORT_SYMBOL(module_refcount);
946 
947 /* This exists whether we can unload or not */
948 static void free_module(struct module *mod);
949 
950 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
951                 unsigned int, flags)
952 {
953         struct module *mod;
954         char name[MODULE_NAME_LEN];
955         int ret, forced = 0;
956 
957         if (!capable(CAP_SYS_MODULE) || modules_disabled)
958                 return -EPERM;
959 
960         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
961                 return -EFAULT;
962         name[MODULE_NAME_LEN-1] = '\0';
963 
964         if (mutex_lock_interruptible(&module_mutex) != 0)
965                 return -EINTR;
966 
967         mod = find_module(name);
968         if (!mod) {
969                 ret = -ENOENT;
970                 goto out;
971         }
972 
973         if (!list_empty(&mod->source_list)) {
974                 /* Other modules depend on us: get rid of them first. */
975                 ret = -EWOULDBLOCK;
976                 goto out;
977         }
978 
979         /* Doing init or already dying? */
980         if (mod->state != MODULE_STATE_LIVE) {
981                 /* FIXME: if (force), slam module count damn the torpedoes */
982                 pr_debug("%s already dying\n", mod->name);
983                 ret = -EBUSY;
984                 goto out;
985         }
986 
987         /* If it has an init func, it must have an exit func to unload */
988         if (mod->init && !mod->exit) {
989                 forced = try_force_unload(flags);
990                 if (!forced) {
991                         /* This module can't be removed */
992                         ret = -EBUSY;
993                         goto out;
994                 }
995         }
996 
997         /* Stop the machine so refcounts can't move and disable module. */
998         ret = try_stop_module(mod, flags, &forced);
999         if (ret != 0)
1000                 goto out;
1001 
1002         mutex_unlock(&module_mutex);
1003         /* Final destruction now no one is using it. */
1004         if (mod->exit != NULL)
1005                 mod->exit();
1006         blocking_notifier_call_chain(&module_notify_list,
1007                                      MODULE_STATE_GOING, mod);
1008         async_synchronize_full();
1009 
1010         /* Store the name of the last unloaded module for diagnostic purposes */
1011         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1012 
1013         free_module(mod);
1014         return 0;
1015 out:
1016         mutex_unlock(&module_mutex);
1017         return ret;
1018 }
1019 
1020 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1021 {
1022         struct module_use *use;
1023         int printed_something = 0;
1024 
1025         seq_printf(m, " %i ", module_refcount(mod));
1026 
1027         /*
1028          * Always include a trailing , so userspace can differentiate
1029          * between this and the old multi-field proc format.
1030          */
1031         list_for_each_entry(use, &mod->source_list, source_list) {
1032                 printed_something = 1;
1033                 seq_printf(m, "%s,", use->source->name);
1034         }
1035 
1036         if (mod->init != NULL && mod->exit == NULL) {
1037                 printed_something = 1;
1038                 seq_puts(m, "[permanent],");
1039         }
1040 
1041         if (!printed_something)
1042                 seq_puts(m, "-");
1043 }
1044 
1045 void __symbol_put(const char *symbol)
1046 {
1047         struct module *owner;
1048 
1049         preempt_disable();
1050         if (!find_symbol(symbol, &owner, NULL, true, false))
1051                 BUG();
1052         module_put(owner);
1053         preempt_enable();
1054 }
1055 EXPORT_SYMBOL(__symbol_put);
1056 
1057 /* Note this assumes addr is a function, which it currently always is. */
1058 void symbol_put_addr(void *addr)
1059 {
1060         struct module *modaddr;
1061         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1062 
1063         if (core_kernel_text(a))
1064                 return;
1065 
1066         /* module_text_address is safe here: we're supposed to have reference
1067          * to module from symbol_get, so it can't go away. */
1068         modaddr = __module_text_address(a);
1069         BUG_ON(!modaddr);
1070         module_put(modaddr);
1071 }
1072 EXPORT_SYMBOL_GPL(symbol_put_addr);
1073 
1074 static ssize_t show_refcnt(struct module_attribute *mattr,
1075                            struct module_kobject *mk, char *buffer)
1076 {
1077         return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1078 }
1079 
1080 static struct module_attribute modinfo_refcnt =
1081         __ATTR(refcnt, 0444, show_refcnt, NULL);
1082 
1083 void __module_get(struct module *module)
1084 {
1085         if (module) {
1086                 preempt_disable();
1087                 atomic_inc(&module->refcnt);
1088                 trace_module_get(module, _RET_IP_);
1089                 preempt_enable();
1090         }
1091 }
1092 EXPORT_SYMBOL(__module_get);
1093 
1094 bool try_module_get(struct module *module)
1095 {
1096         bool ret = true;
1097 
1098         if (module) {
1099                 preempt_disable();
1100                 /* Note: here, we can fail to get a reference */
1101                 if (likely(module_is_live(module) &&
1102                            atomic_inc_not_zero(&module->refcnt) != 0))
1103                         trace_module_get(module, _RET_IP_);
1104                 else
1105                         ret = false;
1106 
1107                 preempt_enable();
1108         }
1109         return ret;
1110 }
1111 EXPORT_SYMBOL(try_module_get);
1112 
1113 void module_put(struct module *module)
1114 {
1115         int ret;
1116 
1117         if (module) {
1118                 preempt_disable();
1119                 ret = atomic_dec_if_positive(&module->refcnt);
1120                 WARN_ON(ret < 0);       /* Failed to put refcount */
1121                 trace_module_put(module, _RET_IP_);
1122                 preempt_enable();
1123         }
1124 }
1125 EXPORT_SYMBOL(module_put);
1126 
1127 #else /* !CONFIG_MODULE_UNLOAD */
1128 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1129 {
1130         /* We don't know the usage count, or what modules are using. */
1131         seq_puts(m, " - -");
1132 }
1133 
1134 static inline void module_unload_free(struct module *mod)
1135 {
1136 }
1137 
1138 int ref_module(struct module *a, struct module *b)
1139 {
1140         return strong_try_module_get(b);
1141 }
1142 EXPORT_SYMBOL_GPL(ref_module);
1143 
1144 static inline int module_unload_init(struct module *mod)
1145 {
1146         return 0;
1147 }
1148 #endif /* CONFIG_MODULE_UNLOAD */
1149 
1150 static size_t module_flags_taint(struct module *mod, char *buf)
1151 {
1152         size_t l = 0;
1153 
1154         if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1155                 buf[l++] = 'P';
1156         if (mod->taints & (1 << TAINT_OOT_MODULE))
1157                 buf[l++] = 'O';
1158         if (mod->taints & (1 << TAINT_FORCED_MODULE))
1159                 buf[l++] = 'F';
1160         if (mod->taints & (1 << TAINT_CRAP))
1161                 buf[l++] = 'C';
1162         if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1163                 buf[l++] = 'E';
1164         /*
1165          * TAINT_FORCED_RMMOD: could be added.
1166          * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1167          * apply to modules.
1168          */
1169         return l;
1170 }
1171 
1172 static ssize_t show_initstate(struct module_attribute *mattr,
1173                               struct module_kobject *mk, char *buffer)
1174 {
1175         const char *state = "unknown";
1176 
1177         switch (mk->mod->state) {
1178         case MODULE_STATE_LIVE:
1179                 state = "live";
1180                 break;
1181         case MODULE_STATE_COMING:
1182                 state = "coming";
1183                 break;
1184         case MODULE_STATE_GOING:
1185                 state = "going";
1186                 break;
1187         default:
1188                 BUG();
1189         }
1190         return sprintf(buffer, "%s\n", state);
1191 }
1192 
1193 static struct module_attribute modinfo_initstate =
1194         __ATTR(initstate, 0444, show_initstate, NULL);
1195 
1196 static ssize_t store_uevent(struct module_attribute *mattr,
1197                             struct module_kobject *mk,
1198                             const char *buffer, size_t count)
1199 {
1200         enum kobject_action action;
1201 
1202         if (kobject_action_type(buffer, count, &action) == 0)
1203                 kobject_uevent(&mk->kobj, action);
1204         return count;
1205 }
1206 
1207 struct module_attribute module_uevent =
1208         __ATTR(uevent, 0200, NULL, store_uevent);
1209 
1210 static ssize_t show_coresize(struct module_attribute *mattr,
1211                              struct module_kobject *mk, char *buffer)
1212 {
1213         return sprintf(buffer, "%u\n", mk->mod->core_size);
1214 }
1215 
1216 static struct module_attribute modinfo_coresize =
1217         __ATTR(coresize, 0444, show_coresize, NULL);
1218 
1219 static ssize_t show_initsize(struct module_attribute *mattr,
1220                              struct module_kobject *mk, char *buffer)
1221 {
1222         return sprintf(buffer, "%u\n", mk->mod->init_size);
1223 }
1224 
1225 static struct module_attribute modinfo_initsize =
1226         __ATTR(initsize, 0444, show_initsize, NULL);
1227 
1228 static ssize_t show_taint(struct module_attribute *mattr,
1229                           struct module_kobject *mk, char *buffer)
1230 {
1231         size_t l;
1232 
1233         l = module_flags_taint(mk->mod, buffer);
1234         buffer[l++] = '\n';
1235         return l;
1236 }
1237 
1238 static struct module_attribute modinfo_taint =
1239         __ATTR(taint, 0444, show_taint, NULL);
1240 
1241 static struct module_attribute *modinfo_attrs[] = {
1242         &module_uevent,
1243         &modinfo_version,
1244         &modinfo_srcversion,
1245         &modinfo_initstate,
1246         &modinfo_coresize,
1247         &modinfo_initsize,
1248         &modinfo_taint,
1249 #ifdef CONFIG_MODULE_UNLOAD
1250         &modinfo_refcnt,
1251 #endif
1252         NULL,
1253 };
1254 
1255 static const char vermagic[] = VERMAGIC_STRING;
1256 
1257 static int try_to_force_load(struct module *mod, const char *reason)
1258 {
1259 #ifdef CONFIG_MODULE_FORCE_LOAD
1260         if (!test_taint(TAINT_FORCED_MODULE))
1261                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1262         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1263         return 0;
1264 #else
1265         return -ENOEXEC;
1266 #endif
1267 }
1268 
1269 #ifdef CONFIG_MODVERSIONS
1270 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1271 static unsigned long maybe_relocated(unsigned long crc,
1272                                      const struct module *crc_owner)
1273 {
1274 #ifdef ARCH_RELOCATES_KCRCTAB
1275         if (crc_owner == NULL)
1276                 return crc - (unsigned long)reloc_start;
1277 #endif
1278         return crc;
1279 }
1280 
1281 static int check_version(Elf_Shdr *sechdrs,
1282                          unsigned int versindex,
1283                          const char *symname,
1284                          struct module *mod,
1285                          const unsigned long *crc,
1286                          const struct module *crc_owner)
1287 {
1288         unsigned int i, num_versions;
1289         struct modversion_info *versions;
1290 
1291         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1292         if (!crc)
1293                 return 1;
1294 
1295         /* No versions at all?  modprobe --force does this. */
1296         if (versindex == 0)
1297                 return try_to_force_load(mod, symname) == 0;
1298 
1299         versions = (void *) sechdrs[versindex].sh_addr;
1300         num_versions = sechdrs[versindex].sh_size
1301                 / sizeof(struct modversion_info);
1302 
1303         for (i = 0; i < num_versions; i++) {
1304                 if (strcmp(versions[i].name, symname) != 0)
1305                         continue;
1306 
1307                 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1308                         return 1;
1309                 pr_debug("Found checksum %lX vs module %lX\n",
1310                        maybe_relocated(*crc, crc_owner), versions[i].crc);
1311                 goto bad_version;
1312         }
1313 
1314         pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1315         return 0;
1316 
1317 bad_version:
1318         pr_warn("%s: disagrees about version of symbol %s\n",
1319                mod->name, symname);
1320         return 0;
1321 }
1322 
1323 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1324                                           unsigned int versindex,
1325                                           struct module *mod)
1326 {
1327         const unsigned long *crc;
1328 
1329         /*
1330          * Since this should be found in kernel (which can't be removed), no
1331          * locking is necessary -- use preempt_disable() to placate lockdep.
1332          */
1333         preempt_disable();
1334         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1335                          &crc, true, false)) {
1336                 preempt_enable();
1337                 BUG();
1338         }
1339         preempt_enable();
1340         return check_version(sechdrs, versindex,
1341                              VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1342                              NULL);
1343 }
1344 
1345 /* First part is kernel version, which we ignore if module has crcs. */
1346 static inline int same_magic(const char *amagic, const char *bmagic,
1347                              bool has_crcs)
1348 {
1349         if (has_crcs) {
1350                 amagic += strcspn(amagic, " ");
1351                 bmagic += strcspn(bmagic, " ");
1352         }
1353         return strcmp(amagic, bmagic) == 0;
1354 }
1355 #else
1356 static inline int check_version(Elf_Shdr *sechdrs,
1357                                 unsigned int versindex,
1358                                 const char *symname,
1359                                 struct module *mod,
1360                                 const unsigned long *crc,
1361                                 const struct module *crc_owner)
1362 {
1363         return 1;
1364 }
1365 
1366 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1367                                           unsigned int versindex,
1368                                           struct module *mod)
1369 {
1370         return 1;
1371 }
1372 
1373 static inline int same_magic(const char *amagic, const char *bmagic,
1374                              bool has_crcs)
1375 {
1376         return strcmp(amagic, bmagic) == 0;
1377 }
1378 #endif /* CONFIG_MODVERSIONS */
1379 
1380 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1381 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1382                                                   const struct load_info *info,
1383                                                   const char *name,
1384                                                   char ownername[])
1385 {
1386         struct module *owner;
1387         const struct kernel_symbol *sym;
1388         const unsigned long *crc;
1389         int err;
1390 
1391         /*
1392          * The module_mutex should not be a heavily contended lock;
1393          * if we get the occasional sleep here, we'll go an extra iteration
1394          * in the wait_event_interruptible(), which is harmless.
1395          */
1396         sched_annotate_sleep();
1397         mutex_lock(&module_mutex);
1398         sym = find_symbol(name, &owner, &crc,
1399                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1400         if (!sym)
1401                 goto unlock;
1402 
1403         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1404                            owner)) {
1405                 sym = ERR_PTR(-EINVAL);
1406                 goto getname;
1407         }
1408 
1409         err = ref_module(mod, owner);
1410         if (err) {
1411                 sym = ERR_PTR(err);
1412                 goto getname;
1413         }
1414 
1415 getname:
1416         /* We must make copy under the lock if we failed to get ref. */
1417         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1418 unlock:
1419         mutex_unlock(&module_mutex);
1420         return sym;
1421 }
1422 
1423 static const struct kernel_symbol *
1424 resolve_symbol_wait(struct module *mod,
1425                     const struct load_info *info,
1426                     const char *name)
1427 {
1428         const struct kernel_symbol *ksym;
1429         char owner[MODULE_NAME_LEN];
1430 
1431         if (wait_event_interruptible_timeout(module_wq,
1432                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1433                         || PTR_ERR(ksym) != -EBUSY,
1434                                              30 * HZ) <= 0) {
1435                 pr_warn("%s: gave up waiting for init of module %s.\n",
1436                         mod->name, owner);
1437         }
1438         return ksym;
1439 }
1440 
1441 /*
1442  * /sys/module/foo/sections stuff
1443  * J. Corbet <corbet@lwn.net>
1444  */
1445 #ifdef CONFIG_SYSFS
1446 
1447 #ifdef CONFIG_KALLSYMS
1448 static inline bool sect_empty(const Elf_Shdr *sect)
1449 {
1450         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1451 }
1452 
1453 struct module_sect_attr {
1454         struct module_attribute mattr;
1455         char *name;
1456         unsigned long address;
1457 };
1458 
1459 struct module_sect_attrs {
1460         struct attribute_group grp;
1461         unsigned int nsections;
1462         struct module_sect_attr attrs[0];
1463 };
1464 
1465 static ssize_t module_sect_show(struct module_attribute *mattr,
1466                                 struct module_kobject *mk, char *buf)
1467 {
1468         struct module_sect_attr *sattr =
1469                 container_of(mattr, struct module_sect_attr, mattr);
1470         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1471 }
1472 
1473 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1474 {
1475         unsigned int section;
1476 
1477         for (section = 0; section < sect_attrs->nsections; section++)
1478                 kfree(sect_attrs->attrs[section].name);
1479         kfree(sect_attrs);
1480 }
1481 
1482 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1483 {
1484         unsigned int nloaded = 0, i, size[2];
1485         struct module_sect_attrs *sect_attrs;
1486         struct module_sect_attr *sattr;
1487         struct attribute **gattr;
1488 
1489         /* Count loaded sections and allocate structures */
1490         for (i = 0; i < info->hdr->e_shnum; i++)
1491                 if (!sect_empty(&info->sechdrs[i]))
1492                         nloaded++;
1493         size[0] = ALIGN(sizeof(*sect_attrs)
1494                         + nloaded * sizeof(sect_attrs->attrs[0]),
1495                         sizeof(sect_attrs->grp.attrs[0]));
1496         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1497         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1498         if (sect_attrs == NULL)
1499                 return;
1500 
1501         /* Setup section attributes. */
1502         sect_attrs->grp.name = "sections";
1503         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1504 
1505         sect_attrs->nsections = 0;
1506         sattr = &sect_attrs->attrs[0];
1507         gattr = &sect_attrs->grp.attrs[0];
1508         for (i = 0; i < info->hdr->e_shnum; i++) {
1509                 Elf_Shdr *sec = &info->sechdrs[i];
1510                 if (sect_empty(sec))
1511                         continue;
1512                 sattr->address = sec->sh_addr;
1513                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1514                                         GFP_KERNEL);
1515                 if (sattr->name == NULL)
1516                         goto out;
1517                 sect_attrs->nsections++;
1518                 sysfs_attr_init(&sattr->mattr.attr);
1519                 sattr->mattr.show = module_sect_show;
1520                 sattr->mattr.store = NULL;
1521                 sattr->mattr.attr.name = sattr->name;
1522                 sattr->mattr.attr.mode = S_IRUGO;
1523                 *(gattr++) = &(sattr++)->mattr.attr;
1524         }
1525         *gattr = NULL;
1526 
1527         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1528                 goto out;
1529 
1530         mod->sect_attrs = sect_attrs;
1531         return;
1532   out:
1533         free_sect_attrs(sect_attrs);
1534 }
1535 
1536 static void remove_sect_attrs(struct module *mod)
1537 {
1538         if (mod->sect_attrs) {
1539                 sysfs_remove_group(&mod->mkobj.kobj,
1540                                    &mod->sect_attrs->grp);
1541                 /* We are positive that no one is using any sect attrs
1542                  * at this point.  Deallocate immediately. */
1543                 free_sect_attrs(mod->sect_attrs);
1544                 mod->sect_attrs = NULL;
1545         }
1546 }
1547 
1548 /*
1549  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1550  */
1551 
1552 struct module_notes_attrs {
1553         struct kobject *dir;
1554         unsigned int notes;
1555         struct bin_attribute attrs[0];
1556 };
1557 
1558 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1559                                  struct bin_attribute *bin_attr,
1560                                  char *buf, loff_t pos, size_t count)
1561 {
1562         /*
1563          * The caller checked the pos and count against our size.
1564          */
1565         memcpy(buf, bin_attr->private + pos, count);
1566         return count;
1567 }
1568 
1569 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1570                              unsigned int i)
1571 {
1572         if (notes_attrs->dir) {
1573                 while (i-- > 0)
1574                         sysfs_remove_bin_file(notes_attrs->dir,
1575                                               &notes_attrs->attrs[i]);
1576                 kobject_put(notes_attrs->dir);
1577         }
1578         kfree(notes_attrs);
1579 }
1580 
1581 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1582 {
1583         unsigned int notes, loaded, i;
1584         struct module_notes_attrs *notes_attrs;
1585         struct bin_attribute *nattr;
1586 
1587         /* failed to create section attributes, so can't create notes */
1588         if (!mod->sect_attrs)
1589                 return;
1590 
1591         /* Count notes sections and allocate structures.  */
1592         notes = 0;
1593         for (i = 0; i < info->hdr->e_shnum; i++)
1594                 if (!sect_empty(&info->sechdrs[i]) &&
1595                     (info->sechdrs[i].sh_type == SHT_NOTE))
1596                         ++notes;
1597 
1598         if (notes == 0)
1599                 return;
1600 
1601         notes_attrs = kzalloc(sizeof(*notes_attrs)
1602                               + notes * sizeof(notes_attrs->attrs[0]),
1603                               GFP_KERNEL);
1604         if (notes_attrs == NULL)
1605                 return;
1606 
1607         notes_attrs->notes = notes;
1608         nattr = &notes_attrs->attrs[0];
1609         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1610                 if (sect_empty(&info->sechdrs[i]))
1611                         continue;
1612                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1613                         sysfs_bin_attr_init(nattr);
1614                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1615                         nattr->attr.mode = S_IRUGO;
1616                         nattr->size = info->sechdrs[i].sh_size;
1617                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1618                         nattr->read = module_notes_read;
1619                         ++nattr;
1620                 }
1621                 ++loaded;
1622         }
1623 
1624         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1625         if (!notes_attrs->dir)
1626                 goto out;
1627 
1628         for (i = 0; i < notes; ++i)
1629                 if (sysfs_create_bin_file(notes_attrs->dir,
1630                                           &notes_attrs->attrs[i]))
1631                         goto out;
1632 
1633         mod->notes_attrs = notes_attrs;
1634         return;
1635 
1636   out:
1637         free_notes_attrs(notes_attrs, i);
1638 }
1639 
1640 static void remove_notes_attrs(struct module *mod)
1641 {
1642         if (mod->notes_attrs)
1643                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1644 }
1645 
1646 #else
1647 
1648 static inline void add_sect_attrs(struct module *mod,
1649                                   const struct load_info *info)
1650 {
1651 }
1652 
1653 static inline void remove_sect_attrs(struct module *mod)
1654 {
1655 }
1656 
1657 static inline void add_notes_attrs(struct module *mod,
1658                                    const struct load_info *info)
1659 {
1660 }
1661 
1662 static inline void remove_notes_attrs(struct module *mod)
1663 {
1664 }
1665 #endif /* CONFIG_KALLSYMS */
1666 
1667 static void add_usage_links(struct module *mod)
1668 {
1669 #ifdef CONFIG_MODULE_UNLOAD
1670         struct module_use *use;
1671         int nowarn;
1672 
1673         mutex_lock(&module_mutex);
1674         list_for_each_entry(use, &mod->target_list, target_list) {
1675                 nowarn = sysfs_create_link(use->target->holders_dir,
1676                                            &mod->mkobj.kobj, mod->name);
1677         }
1678         mutex_unlock(&module_mutex);
1679 #endif
1680 }
1681 
1682 static void del_usage_links(struct module *mod)
1683 {
1684 #ifdef CONFIG_MODULE_UNLOAD
1685         struct module_use *use;
1686 
1687         mutex_lock(&module_mutex);
1688         list_for_each_entry(use, &mod->target_list, target_list)
1689                 sysfs_remove_link(use->target->holders_dir, mod->name);
1690         mutex_unlock(&module_mutex);
1691 #endif
1692 }
1693 
1694 static int module_add_modinfo_attrs(struct module *mod)
1695 {
1696         struct module_attribute *attr;
1697         struct module_attribute *temp_attr;
1698         int error = 0;
1699         int i;
1700 
1701         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1702                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1703                                         GFP_KERNEL);
1704         if (!mod->modinfo_attrs)
1705                 return -ENOMEM;
1706 
1707         temp_attr = mod->modinfo_attrs;
1708         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1709                 if (!attr->test ||
1710                     (attr->test && attr->test(mod))) {
1711                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1712                         sysfs_attr_init(&temp_attr->attr);
1713                         error = sysfs_create_file(&mod->mkobj.kobj,
1714                                         &temp_attr->attr);
1715                         ++temp_attr;
1716                 }
1717         }
1718         return error;
1719 }
1720 
1721 static void module_remove_modinfo_attrs(struct module *mod)
1722 {
1723         struct module_attribute *attr;
1724         int i;
1725 
1726         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1727                 /* pick a field to test for end of list */
1728                 if (!attr->attr.name)
1729                         break;
1730                 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1731                 if (attr->free)
1732                         attr->free(mod);
1733         }
1734         kfree(mod->modinfo_attrs);
1735 }
1736 
1737 static void mod_kobject_put(struct module *mod)
1738 {
1739         DECLARE_COMPLETION_ONSTACK(c);
1740         mod->mkobj.kobj_completion = &c;
1741         kobject_put(&mod->mkobj.kobj);
1742         wait_for_completion(&c);
1743 }
1744 
1745 static int mod_sysfs_init(struct module *mod)
1746 {
1747         int err;
1748         struct kobject *kobj;
1749 
1750         if (!module_sysfs_initialized) {
1751                 pr_err("%s: module sysfs not initialized\n", mod->name);
1752                 err = -EINVAL;
1753                 goto out;
1754         }
1755 
1756         kobj = kset_find_obj(module_kset, mod->name);
1757         if (kobj) {
1758                 pr_err("%s: module is already loaded\n", mod->name);
1759                 kobject_put(kobj);
1760                 err = -EINVAL;
1761                 goto out;
1762         }
1763 
1764         mod->mkobj.mod = mod;
1765 
1766         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1767         mod->mkobj.kobj.kset = module_kset;
1768         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1769                                    "%s", mod->name);
1770         if (err)
1771                 mod_kobject_put(mod);
1772 
1773         /* delay uevent until full sysfs population */
1774 out:
1775         return err;
1776 }
1777 
1778 static int mod_sysfs_setup(struct module *mod,
1779                            const struct load_info *info,
1780                            struct kernel_param *kparam,
1781                            unsigned int num_params)
1782 {
1783         int err;
1784 
1785         err = mod_sysfs_init(mod);
1786         if (err)
1787                 goto out;
1788 
1789         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1790         if (!mod->holders_dir) {
1791                 err = -ENOMEM;
1792                 goto out_unreg;
1793         }
1794 
1795         err = module_param_sysfs_setup(mod, kparam, num_params);
1796         if (err)
1797                 goto out_unreg_holders;
1798 
1799         err = module_add_modinfo_attrs(mod);
1800         if (err)
1801                 goto out_unreg_param;
1802 
1803         add_usage_links(mod);
1804         add_sect_attrs(mod, info);
1805         add_notes_attrs(mod, info);
1806 
1807         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1808         return 0;
1809 
1810 out_unreg_param:
1811         module_param_sysfs_remove(mod);
1812 out_unreg_holders:
1813         kobject_put(mod->holders_dir);
1814 out_unreg:
1815         mod_kobject_put(mod);
1816 out:
1817         return err;
1818 }
1819 
1820 static void mod_sysfs_fini(struct module *mod)
1821 {
1822         remove_notes_attrs(mod);
1823         remove_sect_attrs(mod);
1824         mod_kobject_put(mod);
1825 }
1826 
1827 static void init_param_lock(struct module *mod)
1828 {
1829         mutex_init(&mod->param_lock);
1830 }
1831 #else /* !CONFIG_SYSFS */
1832 
1833 static int mod_sysfs_setup(struct module *mod,
1834                            const struct load_info *info,
1835                            struct kernel_param *kparam,
1836                            unsigned int num_params)
1837 {
1838         return 0;
1839 }
1840 
1841 static void mod_sysfs_fini(struct module *mod)
1842 {
1843 }
1844 
1845 static void module_remove_modinfo_attrs(struct module *mod)
1846 {
1847 }
1848 
1849 static void del_usage_links(struct module *mod)
1850 {
1851 }
1852 
1853 static void init_param_lock(struct module *mod)
1854 {
1855 }
1856 #endif /* CONFIG_SYSFS */
1857 
1858 static void mod_sysfs_teardown(struct module *mod)
1859 {
1860         del_usage_links(mod);
1861         module_remove_modinfo_attrs(mod);
1862         module_param_sysfs_remove(mod);
1863         kobject_put(mod->mkobj.drivers_dir);
1864         kobject_put(mod->holders_dir);
1865         mod_sysfs_fini(mod);
1866 }
1867 
1868 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1869 /*
1870  * LKM RO/NX protection: protect module's text/ro-data
1871  * from modification and any data from execution.
1872  */
1873 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1874 {
1875         unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1876         unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1877 
1878         if (end_pfn > begin_pfn)
1879                 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1880 }
1881 
1882 static void set_section_ro_nx(void *base,
1883                         unsigned long text_size,
1884                         unsigned long ro_size,
1885                         unsigned long total_size)
1886 {
1887         /* begin and end PFNs of the current subsection */
1888         unsigned long begin_pfn;
1889         unsigned long end_pfn;
1890 
1891         /*
1892          * Set RO for module text and RO-data:
1893          * - Always protect first page.
1894          * - Do not protect last partial page.
1895          */
1896         if (ro_size > 0)
1897                 set_page_attributes(base, base + ro_size, set_memory_ro);
1898 
1899         /*
1900          * Set NX permissions for module data:
1901          * - Do not protect first partial page.
1902          * - Always protect last page.
1903          */
1904         if (total_size > text_size) {
1905                 begin_pfn = PFN_UP((unsigned long)base + text_size);
1906                 end_pfn = PFN_UP((unsigned long)base + total_size);
1907                 if (end_pfn > begin_pfn)
1908                         set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1909         }
1910 }
1911 
1912 static void unset_module_core_ro_nx(struct module *mod)
1913 {
1914         set_page_attributes(mod->module_core + mod->core_text_size,
1915                 mod->module_core + mod->core_size,
1916                 set_memory_x);
1917         set_page_attributes(mod->module_core,
1918                 mod->module_core + mod->core_ro_size,
1919                 set_memory_rw);
1920 }
1921 
1922 static void unset_module_init_ro_nx(struct module *mod)
1923 {
1924         set_page_attributes(mod->module_init + mod->init_text_size,
1925                 mod->module_init + mod->init_size,
1926                 set_memory_x);
1927         set_page_attributes(mod->module_init,
1928                 mod->module_init + mod->init_ro_size,
1929                 set_memory_rw);
1930 }
1931 
1932 /* Iterate through all modules and set each module's text as RW */
1933 void set_all_modules_text_rw(void)
1934 {
1935         struct module *mod;
1936 
1937         mutex_lock(&module_mutex);
1938         list_for_each_entry_rcu(mod, &modules, list) {
1939                 if (mod->state == MODULE_STATE_UNFORMED)
1940                         continue;
1941                 if ((mod->module_core) && (mod->core_text_size)) {
1942                         set_page_attributes(mod->module_core,
1943                                                 mod->module_core + mod->core_text_size,
1944                                                 set_memory_rw);
1945                 }
1946                 if ((mod->module_init) && (mod->init_text_size)) {
1947                         set_page_attributes(mod->module_init,
1948                                                 mod->module_init + mod->init_text_size,
1949                                                 set_memory_rw);
1950                 }
1951         }
1952         mutex_unlock(&module_mutex);
1953 }
1954 
1955 /* Iterate through all modules and set each module's text as RO */
1956 void set_all_modules_text_ro(void)
1957 {
1958         struct module *mod;
1959 
1960         mutex_lock(&module_mutex);
1961         list_for_each_entry_rcu(mod, &modules, list) {
1962                 if (mod->state == MODULE_STATE_UNFORMED)
1963                         continue;
1964                 if ((mod->module_core) && (mod->core_text_size)) {
1965                         set_page_attributes(mod->module_core,
1966                                                 mod->module_core + mod->core_text_size,
1967                                                 set_memory_ro);
1968                 }
1969                 if ((mod->module_init) && (mod->init_text_size)) {
1970                         set_page_attributes(mod->module_init,
1971                                                 mod->module_init + mod->init_text_size,
1972                                                 set_memory_ro);
1973                 }
1974         }
1975         mutex_unlock(&module_mutex);
1976 }
1977 #else
1978 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1979 static void unset_module_core_ro_nx(struct module *mod) { }
1980 static void unset_module_init_ro_nx(struct module *mod) { }
1981 #endif
1982 
1983 void __weak module_memfree(void *module_region)
1984 {
1985         vfree(module_region);
1986 }
1987 
1988 void __weak module_arch_cleanup(struct module *mod)
1989 {
1990 }
1991 
1992 void __weak module_arch_freeing_init(struct module *mod)
1993 {
1994 }
1995 
1996 /* Free a module, remove from lists, etc. */
1997 static void free_module(struct module *mod)
1998 {
1999         trace_module_free(mod);
2000 
2001         mod_sysfs_teardown(mod);
2002 
2003         /* We leave it in list to prevent duplicate loads, but make sure
2004          * that noone uses it while it's being deconstructed. */
2005         mutex_lock(&module_mutex);
2006         mod->state = MODULE_STATE_UNFORMED;
2007         mutex_unlock(&module_mutex);
2008 
2009         /* Remove dynamic debug info */
2010         ddebug_remove_module(mod->name);
2011 
2012         /* Arch-specific cleanup. */
2013         module_arch_cleanup(mod);
2014 
2015         /* Module unload stuff */
2016         module_unload_free(mod);
2017 
2018         /* Free any allocated parameters. */
2019         destroy_params(mod->kp, mod->num_kp);
2020 
2021         /* Now we can delete it from the lists */
2022         mutex_lock(&module_mutex);
2023         /* Unlink carefully: kallsyms could be walking list. */
2024         list_del_rcu(&mod->list);
2025         mod_tree_remove(mod);
2026         /* Remove this module from bug list, this uses list_del_rcu */
2027         module_bug_cleanup(mod);
2028         /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2029         synchronize_sched();
2030         mutex_unlock(&module_mutex);
2031 
2032         /* This may be NULL, but that's OK */
2033         unset_module_init_ro_nx(mod);
2034         module_arch_freeing_init(mod);
2035         module_memfree(mod->module_init);
2036         kfree(mod->args);
2037         percpu_modfree(mod);
2038 
2039         /* Free lock-classes; relies on the preceding sync_rcu(). */
2040         lockdep_free_key_range(mod->module_core, mod->core_size);
2041 
2042         /* Finally, free the core (containing the module structure) */
2043         unset_module_core_ro_nx(mod);
2044         module_memfree(mod->module_core);
2045 
2046 #ifdef CONFIG_MPU
2047         update_protections(current->mm);
2048 #endif
2049 }
2050 
2051 void *__symbol_get(const char *symbol)
2052 {
2053         struct module *owner;
2054         const struct kernel_symbol *sym;
2055 
2056         preempt_disable();
2057         sym = find_symbol(symbol, &owner, NULL, true, true);
2058         if (sym && strong_try_module_get(owner))
2059                 sym = NULL;
2060         preempt_enable();
2061 
2062         return sym ? (void *)sym->value : NULL;
2063 }
2064 EXPORT_SYMBOL_GPL(__symbol_get);
2065 
2066 /*
2067  * Ensure that an exported symbol [global namespace] does not already exist
2068  * in the kernel or in some other module's exported symbol table.
2069  *
2070  * You must hold the module_mutex.
2071  */
2072 static int verify_export_symbols(struct module *mod)
2073 {
2074         unsigned int i;
2075         struct module *owner;
2076         const struct kernel_symbol *s;
2077         struct {
2078                 const struct kernel_symbol *sym;
2079                 unsigned int num;
2080         } arr[] = {
2081                 { mod->syms, mod->num_syms },
2082                 { mod->gpl_syms, mod->num_gpl_syms },
2083                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2084 #ifdef CONFIG_UNUSED_SYMBOLS
2085                 { mod->unused_syms, mod->num_unused_syms },
2086                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2087 #endif
2088         };
2089 
2090         for (i = 0; i < ARRAY_SIZE(arr); i++) {
2091                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2092                         if (find_symbol(s->name, &owner, NULL, true, false)) {
2093                                 pr_err("%s: exports duplicate symbol %s"
2094                                        " (owned by %s)\n",
2095                                        mod->name, s->name, module_name(owner));
2096                                 return -ENOEXEC;
2097                         }
2098                 }
2099         }
2100         return 0;
2101 }
2102 
2103 /* Change all symbols so that st_value encodes the pointer directly. */
2104 static int simplify_symbols(struct module *mod, const struct load_info *info)
2105 {
2106         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2107         Elf_Sym *sym = (void *)symsec->sh_addr;
2108         unsigned long secbase;
2109         unsigned int i;
2110         int ret = 0;
2111         const struct kernel_symbol *ksym;
2112 
2113         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2114                 const char *name = info->strtab + sym[i].st_name;
2115 
2116                 switch (sym[i].st_shndx) {
2117                 case SHN_COMMON:
2118                         /* Ignore common symbols */
2119                         if (!strncmp(name, "__gnu_lto", 9))
2120                                 break;
2121 
2122                         /* We compiled with -fno-common.  These are not
2123                            supposed to happen.  */
2124                         pr_debug("Common symbol: %s\n", name);
2125                         pr_warn("%s: please compile with -fno-common\n",
2126                                mod->name);
2127                         ret = -ENOEXEC;
2128                         break;
2129 
2130                 case SHN_ABS:
2131                         /* Don't need to do anything */
2132                         pr_debug("Absolute symbol: 0x%08lx\n",
2133                                (long)sym[i].st_value);
2134                         break;
2135 
2136                 case SHN_UNDEF:
2137                         ksym = resolve_symbol_wait(mod, info, name);
2138                         /* Ok if resolved.  */
2139                         if (ksym && !IS_ERR(ksym)) {
2140                                 sym[i].st_value = ksym->value;
2141                                 break;
2142                         }
2143 
2144                         /* Ok if weak.  */
2145                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2146                                 break;
2147 
2148                         pr_warn("%s: Unknown symbol %s (err %li)\n",
2149                                 mod->name, name, PTR_ERR(ksym));
2150                         ret = PTR_ERR(ksym) ?: -ENOENT;
2151                         break;
2152 
2153                 default:
2154                         /* Divert to percpu allocation if a percpu var. */
2155                         if (sym[i].st_shndx == info->index.pcpu)
2156                                 secbase = (unsigned long)mod_percpu(mod);
2157                         else
2158                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2159                         sym[i].st_value += secbase;
2160                         break;
2161                 }
2162         }
2163 
2164         return ret;
2165 }
2166 
2167 static int apply_relocations(struct module *mod, const struct load_info *info)
2168 {
2169         unsigned int i;
2170         int err = 0;
2171 
2172         /* Now do relocations. */
2173         for (i = 1; i < info->hdr->e_shnum; i++) {
2174                 unsigned int infosec = info->sechdrs[i].sh_info;
2175 
2176                 /* Not a valid relocation section? */
2177                 if (infosec >= info->hdr->e_shnum)
2178                         continue;
2179 
2180                 /* Don't bother with non-allocated sections */
2181                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2182                         continue;
2183 
2184                 if (info->sechdrs[i].sh_type == SHT_REL)
2185                         err = apply_relocate(info->sechdrs, info->strtab,
2186                                              info->index.sym, i, mod);
2187                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2188                         err = apply_relocate_add(info->sechdrs, info->strtab,
2189                                                  info->index.sym, i, mod);
2190                 if (err < 0)
2191                         break;
2192         }
2193         return err;
2194 }
2195 
2196 /* Additional bytes needed by arch in front of individual sections */
2197 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2198                                              unsigned int section)
2199 {
2200         /* default implementation just returns zero */
2201         return 0;
2202 }
2203 
2204 /* Update size with this section: return offset. */
2205 static long get_offset(struct module *mod, unsigned int *size,
2206                        Elf_Shdr *sechdr, unsigned int section)
2207 {
2208         long ret;
2209 
2210         *size += arch_mod_section_prepend(mod, section);
2211         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2212         *size = ret + sechdr->sh_size;
2213         return ret;
2214 }
2215 
2216 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2217    might -- code, read-only data, read-write data, small data.  Tally
2218    sizes, and place the offsets into sh_entsize fields: high bit means it
2219    belongs in init. */
2220 static void layout_sections(struct module *mod, struct load_info *info)
2221 {
2222         static unsigned long const masks[][2] = {
2223                 /* NOTE: all executable code must be the first section
2224                  * in this array; otherwise modify the text_size
2225                  * finder in the two loops below */
2226                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2227                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2228                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2229                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2230         };
2231         unsigned int m, i;
2232 
2233         for (i = 0; i < info->hdr->e_shnum; i++)
2234                 info->sechdrs[i].sh_entsize = ~0UL;
2235 
2236         pr_debug("Core section allocation order:\n");
2237         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2238                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2239                         Elf_Shdr *s = &info->sechdrs[i];
2240                         const char *sname = info->secstrings + s->sh_name;
2241 
2242                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2243                             || (s->sh_flags & masks[m][1])
2244                             || s->sh_entsize != ~0UL
2245                             || strstarts(sname, ".init"))
2246                                 continue;
2247                         s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2248                         pr_debug("\t%s\n", sname);
2249                 }
2250                 switch (m) {
2251                 case 0: /* executable */
2252                         mod->core_size = debug_align(mod->core_size);
2253                         mod->core_text_size = mod->core_size;
2254                         break;
2255                 case 1: /* RO: text and ro-data */
2256                         mod->core_size = debug_align(mod->core_size);
2257                         mod->core_ro_size = mod->core_size;
2258                         break;
2259                 case 3: /* whole core */
2260                         mod->core_size = debug_align(mod->core_size);
2261                         break;
2262                 }
2263         }
2264 
2265         pr_debug("Init section allocation order:\n");
2266         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2267                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2268                         Elf_Shdr *s = &info->sechdrs[i];
2269                         const char *sname = info->secstrings + s->sh_name;
2270 
2271                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2272                             || (s->sh_flags & masks[m][1])
2273                             || s->sh_entsize != ~0UL
2274                             || !strstarts(sname, ".init"))
2275                                 continue;
2276                         s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2277                                          | INIT_OFFSET_MASK);
2278                         pr_debug("\t%s\n", sname);
2279                 }
2280                 switch (m) {
2281                 case 0: /* executable */
2282                         mod->init_size = debug_align(mod->init_size);
2283                         mod->init_text_size = mod->init_size;
2284                         break;
2285                 case 1: /* RO: text and ro-data */
2286                         mod->init_size = debug_align(mod->init_size);
2287                         mod->init_ro_size = mod->init_size;
2288                         break;
2289                 case 3: /* whole init */
2290                         mod->init_size = debug_align(mod->init_size);
2291                         break;
2292                 }
2293         }
2294 }
2295 
2296 static void set_license(struct module *mod, const char *license)
2297 {
2298         if (!license)
2299                 license = "unspecified";
2300 
2301         if (!license_is_gpl_compatible(license)) {
2302                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2303                         pr_warn("%s: module license '%s' taints kernel.\n",
2304                                 mod->name, license);
2305                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2306                                  LOCKDEP_NOW_UNRELIABLE);
2307         }
2308 }
2309 
2310 /* Parse tag=value strings from .modinfo section */
2311 static char *next_string(char *string, unsigned long *secsize)
2312 {
2313         /* Skip non-zero chars */
2314         while (string[0]) {
2315                 string++;
2316                 if ((*secsize)-- <= 1)
2317                         return NULL;
2318         }
2319 
2320         /* Skip any zero padding. */
2321         while (!string[0]) {
2322                 string++;
2323                 if ((*secsize)-- <= 1)
2324                         return NULL;
2325         }
2326         return string;
2327 }
2328 
2329 static char *get_modinfo(struct load_info *info, const char *tag)
2330 {
2331         char *p;
2332         unsigned int taglen = strlen(tag);
2333         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2334         unsigned long size = infosec->sh_size;
2335 
2336         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2337                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2338                         return p + taglen + 1;
2339         }
2340         return NULL;
2341 }
2342 
2343 static void setup_modinfo(struct module *mod, struct load_info *info)
2344 {
2345         struct module_attribute *attr;
2346         int i;
2347 
2348         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2349                 if (attr->setup)
2350                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2351         }
2352 }
2353 
2354 static void free_modinfo(struct module *mod)
2355 {
2356         struct module_attribute *attr;
2357         int i;
2358 
2359         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2360                 if (attr->free)
2361                         attr->free(mod);
2362         }
2363 }
2364 
2365 #ifdef CONFIG_KALLSYMS
2366 
2367 /* lookup symbol in given range of kernel_symbols */
2368 static const struct kernel_symbol *lookup_symbol(const char *name,
2369         const struct kernel_symbol *start,
2370         const struct kernel_symbol *stop)
2371 {
2372         return bsearch(name, start, stop - start,
2373                         sizeof(struct kernel_symbol), cmp_name);
2374 }
2375 
2376 static int is_exported(const char *name, unsigned long value,
2377                        const struct module *mod)
2378 {
2379         const struct kernel_symbol *ks;
2380         if (!mod)
2381                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2382         else
2383                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2384         return ks != NULL && ks->value == value;
2385 }
2386 
2387 /* As per nm */
2388 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2389 {
2390         const Elf_Shdr *sechdrs = info->sechdrs;
2391 
2392         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2393                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2394                         return 'v';
2395                 else
2396                         return 'w';
2397         }
2398         if (sym->st_shndx == SHN_UNDEF)
2399                 return 'U';
2400         if (sym->st_shndx == SHN_ABS)
2401                 return 'a';
2402         if (sym->st_shndx >= SHN_LORESERVE)
2403                 return '?';
2404         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2405                 return 't';
2406         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2407             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2408                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2409                         return 'r';
2410                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2411                         return 'g';
2412                 else
2413                         return 'd';
2414         }
2415         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2416                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2417                         return 's';
2418                 else
2419                         return 'b';
2420         }
2421         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2422                       ".debug")) {
2423                 return 'n';
2424         }
2425         return '?';
2426 }
2427 
2428 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2429                         unsigned int shnum)
2430 {
2431         const Elf_Shdr *sec;
2432 
2433         if (src->st_shndx == SHN_UNDEF
2434             || src->st_shndx >= shnum
2435             || !src->st_name)
2436                 return false;
2437 
2438         sec = sechdrs + src->st_shndx;
2439         if (!(sec->sh_flags & SHF_ALLOC)
2440 #ifndef CONFIG_KALLSYMS_ALL
2441             || !(sec->sh_flags & SHF_EXECINSTR)
2442 #endif
2443             || (sec->sh_entsize & INIT_OFFSET_MASK))
2444                 return false;
2445 
2446         return true;
2447 }
2448 
2449 /*
2450  * We only allocate and copy the strings needed by the parts of symtab
2451  * we keep.  This is simple, but has the effect of making multiple
2452  * copies of duplicates.  We could be more sophisticated, see
2453  * linux-kernel thread starting with
2454  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2455  */
2456 static void layout_symtab(struct module *mod, struct load_info *info)
2457 {
2458         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2459         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2460         const Elf_Sym *src;
2461         unsigned int i, nsrc, ndst, strtab_size = 0;
2462 
2463         /* Put symbol section at end of init part of module. */
2464         symsect->sh_flags |= SHF_ALLOC;
2465         symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2466                                          info->index.sym) | INIT_OFFSET_MASK;
2467         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2468 
2469         src = (void *)info->hdr + symsect->sh_offset;
2470         nsrc = symsect->sh_size / sizeof(*src);
2471 
2472         /* Compute total space required for the core symbols' strtab. */
2473         for (ndst = i = 0; i < nsrc; i++) {
2474                 if (i == 0 ||
2475                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2476                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2477                         ndst++;
2478                 }
2479         }
2480 
2481         /* Append room for core symbols at end of core part. */
2482         info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2483         info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2484         mod->core_size += strtab_size;
2485         mod->core_size = debug_align(mod->core_size);
2486 
2487         /* Put string table section at end of init part of module. */
2488         strsect->sh_flags |= SHF_ALLOC;
2489         strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2490                                          info->index.str) | INIT_OFFSET_MASK;
2491         mod->init_size = debug_align(mod->init_size);
2492         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2493 }
2494 
2495 static void add_kallsyms(struct module *mod, const struct load_info *info)
2496 {
2497         unsigned int i, ndst;
2498         const Elf_Sym *src;
2499         Elf_Sym *dst;
2500         char *s;
2501         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2502 
2503         mod->symtab = (void *)symsec->sh_addr;
2504         mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2505         /* Make sure we get permanent strtab: don't use info->strtab. */
2506         mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2507 
2508         /* Set types up while we still have access to sections. */
2509         for (i = 0; i < mod->num_symtab; i++)
2510                 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2511 
2512         mod->core_symtab = dst = mod->module_core + info->symoffs;
2513         mod->core_strtab = s = mod->module_core + info->stroffs;
2514         src = mod->symtab;
2515         for (ndst = i = 0; i < mod->num_symtab; i++) {
2516                 if (i == 0 ||
2517                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2518                         dst[ndst] = src[i];
2519                         dst[ndst++].st_name = s - mod->core_strtab;
2520                         s += strlcpy(s, &mod->strtab[src[i].st_name],
2521                                      KSYM_NAME_LEN) + 1;
2522                 }
2523         }
2524         mod->core_num_syms = ndst;
2525 }
2526 #else
2527 static inline void layout_symtab(struct module *mod, struct load_info *info)
2528 {
2529 }
2530 
2531 static void add_kallsyms(struct module *mod, const struct load_info *info)
2532 {
2533 }
2534 #endif /* CONFIG_KALLSYMS */
2535 
2536 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2537 {
2538         if (!debug)
2539                 return;
2540 #ifdef CONFIG_DYNAMIC_DEBUG
2541         if (ddebug_add_module(debug, num, debug->modname))
2542                 pr_err("dynamic debug error adding module: %s\n",
2543                         debug->modname);
2544 #endif
2545 }
2546 
2547 static void dynamic_debug_remove(struct _ddebug *debug)
2548 {
2549         if (debug)
2550                 ddebug_remove_module(debug->modname);
2551 }
2552 
2553 void * __weak module_alloc(unsigned long size)
2554 {
2555         return vmalloc_exec(size);
2556 }
2557 
2558 #ifdef CONFIG_DEBUG_KMEMLEAK
2559 static void kmemleak_load_module(const struct module *mod,
2560                                  const struct load_info *info)
2561 {
2562         unsigned int i;
2563 
2564         /* only scan the sections containing data */
2565         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2566 
2567         for (i = 1; i < info->hdr->e_shnum; i++) {
2568                 /* Scan all writable sections that's not executable */
2569                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2570                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2571                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2572                         continue;
2573 
2574                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2575                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2576         }
2577 }
2578 #else
2579 static inline void kmemleak_load_module(const struct module *mod,
2580                                         const struct load_info *info)
2581 {
2582 }
2583 #endif
2584 
2585 #ifdef CONFIG_MODULE_SIG
2586 static int module_sig_check(struct load_info *info)
2587 {
2588         int err = -ENOKEY;
2589         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2590         const void *mod = info->hdr;
2591 
2592         if (info->len > markerlen &&
2593             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2594                 /* We truncate the module to discard the signature */
2595                 info->len -= markerlen;
2596                 err = mod_verify_sig(mod, &info->len);
2597         }
2598 
2599         if (!err) {
2600                 info->sig_ok = true;
2601                 return 0;
2602         }
2603 
2604         /* Not having a signature is only an error if we're strict. */
2605         if (err == -ENOKEY && !sig_enforce)
2606                 err = 0;
2607 
2608         return err;
2609 }
2610 #else /* !CONFIG_MODULE_SIG */
2611 static int module_sig_check(struct load_info *info)
2612 {
2613         return 0;
2614 }
2615 #endif /* !CONFIG_MODULE_SIG */
2616 
2617 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2618 static int elf_header_check(struct load_info *info)
2619 {
2620         if (info->len < sizeof(*(info->hdr)))
2621                 return -ENOEXEC;
2622 
2623         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2624             || info->hdr->e_type != ET_REL
2625             || !elf_check_arch(info->hdr)
2626             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2627                 return -ENOEXEC;
2628 
2629         if (info->hdr->e_shoff >= info->len
2630             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2631                 info->len - info->hdr->e_shoff))
2632                 return -ENOEXEC;
2633 
2634         return 0;
2635 }
2636 
2637 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2638 
2639 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2640 {
2641         do {
2642                 unsigned long n = min(len, COPY_CHUNK_SIZE);
2643 
2644                 if (copy_from_user(dst, usrc, n) != 0)
2645                         return -EFAULT;
2646                 cond_resched();
2647                 dst += n;
2648                 usrc += n;
2649                 len -= n;
2650         } while (len);
2651         return 0;
2652 }
2653 
2654 /* Sets info->hdr and info->len. */
2655 static int copy_module_from_user(const void __user *umod, unsigned long len,
2656                                   struct load_info *info)
2657 {
2658         int err;
2659 
2660         info->len = len;
2661         if (info->len < sizeof(*(info->hdr)))
2662                 return -ENOEXEC;
2663 
2664         err = security_kernel_module_from_file(NULL);
2665         if (err)
2666                 return err;
2667 
2668         /* Suck in entire file: we'll want most of it. */
2669         info->hdr = __vmalloc(info->len,
2670                         GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2671         if (!info->hdr)
2672                 return -ENOMEM;
2673 
2674         if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2675                 vfree(info->hdr);
2676                 return -EFAULT;
2677         }
2678 
2679         return 0;
2680 }
2681 
2682 /* Sets info->hdr and info->len. */
2683 static int copy_module_from_fd(int fd, struct load_info *info)
2684 {
2685         struct fd f = fdget(fd);
2686         int err;
2687         struct kstat stat;
2688         loff_t pos;
2689         ssize_t bytes = 0;
2690 
2691         if (!f.file)
2692                 return -ENOEXEC;
2693 
2694         err = security_kernel_module_from_file(f.file);
2695         if (err)
2696                 goto out;
2697 
2698         err = vfs_getattr(&f.file->f_path, &stat);
2699         if (err)
2700                 goto out;
2701 
2702         if (stat.size > INT_MAX) {
2703                 err = -EFBIG;
2704                 goto out;
2705         }
2706 
2707         /* Don't hand 0 to vmalloc, it whines. */
2708         if (stat.size == 0) {
2709                 err = -EINVAL;
2710                 goto out;
2711         }
2712 
2713         info->hdr = vmalloc(stat.size);
2714         if (!info->hdr) {
2715                 err = -ENOMEM;
2716                 goto out;
2717         }
2718 
2719         pos = 0;
2720         while (pos < stat.size) {
2721                 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2722                                     stat.size - pos);
2723                 if (bytes < 0) {
2724                         vfree(info->hdr);
2725                         err = bytes;
2726                         goto out;
2727                 }
2728                 if (bytes == 0)
2729                         break;
2730                 pos += bytes;
2731         }
2732         info->len = pos;
2733 
2734 out:
2735         fdput(f);
2736         return err;
2737 }
2738 
2739 static void free_copy(struct load_info *info)
2740 {
2741         vfree(info->hdr);
2742 }
2743 
2744 static int rewrite_section_headers(struct load_info *info, int flags)
2745 {
2746         unsigned int i;
2747 
2748         /* This should always be true, but let's be sure. */
2749         info->sechdrs[0].sh_addr = 0;
2750 
2751         for (i = 1; i < info->hdr->e_shnum; i++) {
2752                 Elf_Shdr *shdr = &info->sechdrs[i];
2753                 if (shdr->sh_type != SHT_NOBITS
2754                     && info->len < shdr->sh_offset + shdr->sh_size) {
2755                         pr_err("Module len %lu truncated\n", info->len);
2756                         return -ENOEXEC;
2757                 }
2758 
2759                 /* Mark all sections sh_addr with their address in the
2760                    temporary image. */
2761                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2762 
2763 #ifndef CONFIG_MODULE_UNLOAD
2764                 /* Don't load .exit sections */
2765                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2766                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2767 #endif
2768         }
2769 
2770         /* Track but don't keep modinfo and version sections. */
2771         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2772                 info->index.vers = 0; /* Pretend no __versions section! */
2773         else
2774                 info->index.vers = find_sec(info, "__versions");
2775         info->index.info = find_sec(info, ".modinfo");
2776         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2777         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2778         return 0;
2779 }
2780 
2781 /*
2782  * Set up our basic convenience variables (pointers to section headers,
2783  * search for module section index etc), and do some basic section
2784  * verification.
2785  *
2786  * Return the temporary module pointer (we'll replace it with the final
2787  * one when we move the module sections around).
2788  */
2789 static struct module *setup_load_info(struct load_info *info, int flags)
2790 {
2791         unsigned int i;
2792         int err;
2793         struct module *mod;
2794 
2795         /* Set up the convenience variables */
2796         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2797         info->secstrings = (void *)info->hdr
2798                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2799 
2800         err = rewrite_section_headers(info, flags);
2801         if (err)
2802                 return ERR_PTR(err);
2803 
2804         /* Find internal symbols and strings. */
2805         for (i = 1; i < info->hdr->e_shnum; i++) {
2806                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2807                         info->index.sym = i;
2808                         info->index.str = info->sechdrs[i].sh_link;
2809                         info->strtab = (char *)info->hdr
2810                                 + info->sechdrs[info->index.str].sh_offset;
2811                         break;
2812                 }
2813         }
2814 
2815         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2816         if (!info->index.mod) {
2817                 pr_warn("No module found in object\n");
2818                 return ERR_PTR(-ENOEXEC);
2819         }
2820         /* This is temporary: point mod into copy of data. */
2821         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2822 
2823         if (info->index.sym == 0) {
2824                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2825                 return ERR_PTR(-ENOEXEC);
2826         }
2827 
2828         info->index.pcpu = find_pcpusec(info);
2829 
2830         /* Check module struct version now, before we try to use module. */
2831         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2832                 return ERR_PTR(-ENOEXEC);
2833 
2834         return mod;
2835 }
2836 
2837 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2838 {
2839         const char *modmagic = get_modinfo(info, "vermagic");
2840         int err;
2841 
2842         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2843                 modmagic = NULL;
2844 
2845         /* This is allowed: modprobe --force will invalidate it. */
2846         if (!modmagic) {
2847                 err = try_to_force_load(mod, "bad vermagic");
2848                 if (err)
2849                         return err;
2850         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2851                 pr_err("%s: version magic '%s' should be '%s'\n",
2852                        mod->name, modmagic, vermagic);
2853                 return -ENOEXEC;
2854         }
2855 
2856         if (!get_modinfo(info, "intree"))
2857                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2858 
2859         if (get_modinfo(info, "staging")) {
2860                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2861                 pr_warn("%s: module is from the staging directory, the quality "
2862                         "is unknown, you have been warned.\n", mod->name);
2863         }
2864 
2865         /* Set up license info based on the info section */
2866         set_license(mod, get_modinfo(info, "license"));
2867 
2868         return 0;
2869 }
2870 
2871 static int find_module_sections(struct module *mod, struct load_info *info)
2872 {
2873         mod->kp = section_objs(info, "__param",
2874                                sizeof(*mod->kp), &mod->num_kp);
2875         mod->syms = section_objs(info, "__ksymtab",
2876                                  sizeof(*mod->syms), &mod->num_syms);
2877         mod->crcs = section_addr(info, "__kcrctab");
2878         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2879                                      sizeof(*mod->gpl_syms),
2880                                      &mod->num_gpl_syms);
2881         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2882         mod->gpl_future_syms = section_objs(info,
2883                                             "__ksymtab_gpl_future",
2884                                             sizeof(*mod->gpl_future_syms),
2885                                             &mod->num_gpl_future_syms);
2886         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2887 
2888 #ifdef CONFIG_UNUSED_SYMBOLS
2889         mod->unused_syms = section_objs(info, "__ksymtab_unused",
2890                                         sizeof(*mod->unused_syms),
2891                                         &mod->num_unused_syms);
2892         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2893         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2894                                             sizeof(*mod->unused_gpl_syms),
2895                                             &mod->num_unused_gpl_syms);
2896         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2897 #endif
2898 #ifdef CONFIG_CONSTRUCTORS
2899         mod->ctors = section_objs(info, ".ctors",
2900                                   sizeof(*mod->ctors), &mod->num_ctors);
2901         if (!mod->ctors)
2902                 mod->ctors = section_objs(info, ".init_array",
2903                                 sizeof(*mod->ctors), &mod->num_ctors);
2904         else if (find_sec(info, ".init_array")) {
2905                 /*
2906                  * This shouldn't happen with same compiler and binutils
2907                  * building all parts of the module.
2908                  */
2909                 pr_warn("%s: has both .ctors and .init_array.\n",
2910                        mod->name);
2911                 return -EINVAL;
2912         }
2913 #endif
2914 
2915 #ifdef CONFIG_TRACEPOINTS
2916         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2917                                              sizeof(*mod->tracepoints_ptrs),
2918                                              &mod->num_tracepoints);
2919 #endif
2920 #ifdef HAVE_JUMP_LABEL
2921         mod->jump_entries = section_objs(info, "__jump_table",
2922                                         sizeof(*mod->jump_entries),
2923                                         &mod->num_jump_entries);
2924 #endif
2925 #ifdef CONFIG_EVENT_TRACING
2926         mod->trace_events = section_objs(info, "_ftrace_events",
2927                                          sizeof(*mod->trace_events),
2928                                          &mod->num_trace_events);
2929         mod->trace_enums = section_objs(info, "_ftrace_enum_map",
2930                                         sizeof(*mod->trace_enums),
2931                                         &mod->num_trace_enums);
2932 #endif
2933 #ifdef CONFIG_TRACING
2934         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2935                                          sizeof(*mod->trace_bprintk_fmt_start),
2936                                          &mod->num_trace_bprintk_fmt);
2937 #endif
2938 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2939         /* sechdrs[0].sh_size is always zero */
2940         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2941                                              sizeof(*mod->ftrace_callsites),
2942                                              &mod->num_ftrace_callsites);
2943 #endif
2944 
2945         mod->extable = section_objs(info, "__ex_table",
2946                                     sizeof(*mod->extable), &mod->num_exentries);
2947 
2948         if (section_addr(info, "__obsparm"))
2949                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2950 
2951         info->debug = section_objs(info, "__verbose",
2952                                    sizeof(*info->debug), &info->num_debug);
2953 
2954         return 0;
2955 }
2956 
2957 static int move_module(struct module *mod, struct load_info *info)
2958 {
2959         int i;
2960         void *ptr;
2961 
2962         /* Do the allocs. */
2963         ptr = module_alloc(mod->core_size);
2964         /*
2965          * The pointer to this block is stored in the module structure
2966          * which is inside the block. Just mark it as not being a
2967          * leak.
2968          */
2969         kmemleak_not_leak(ptr);
2970         if (!ptr)
2971                 return -ENOMEM;
2972 
2973         memset(ptr, 0, mod->core_size);
2974         mod->module_core = ptr;
2975 
2976         if (mod->init_size) {
2977                 ptr = module_alloc(mod->init_size);
2978                 /*
2979                  * The pointer to this block is stored in the module structure
2980                  * which is inside the block. This block doesn't need to be
2981                  * scanned as it contains data and code that will be freed
2982                  * after the module is initialized.
2983                  */
2984                 kmemleak_ignore(ptr);
2985                 if (!ptr) {
2986                         module_memfree(mod->module_core);
2987                         return -ENOMEM;
2988                 }
2989                 memset(ptr, 0, mod->init_size);
2990                 mod->module_init = ptr;
2991         } else
2992                 mod->module_init = NULL;
2993 
2994         /* Transfer each section which specifies SHF_ALLOC */
2995         pr_debug("final section addresses:\n");
2996         for (i = 0; i < info->hdr->e_shnum; i++) {
2997                 void *dest;
2998                 Elf_Shdr *shdr = &info->sechdrs[i];
2999 
3000                 if (!(shdr->sh_flags & SHF_ALLOC))
3001                         continue;
3002 
3003                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3004                         dest = mod->module_init
3005                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3006                 else
3007                         dest = mod->module_core + shdr->sh_entsize;
3008 
3009                 if (shdr->sh_type != SHT_NOBITS)
3010                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3011                 /* Update sh_addr to point to copy in image. */
3012                 shdr->sh_addr = (unsigned long)dest;
3013                 pr_debug("\t0x%lx %s\n",
3014                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3015         }
3016 
3017         return 0;
3018 }
3019 
3020 static int check_module_license_and_versions(struct module *mod)
3021 {
3022         /*
3023          * ndiswrapper is under GPL by itself, but loads proprietary modules.
3024          * Don't use add_taint_module(), as it would prevent ndiswrapper from
3025          * using GPL-only symbols it needs.
3026          */
3027         if (strcmp(mod->name, "ndiswrapper") == 0)
3028                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3029 
3030         /* driverloader was caught wrongly pretending to be under GPL */
3031         if (strcmp(mod->name, "driverloader") == 0)
3032                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3033                                  LOCKDEP_NOW_UNRELIABLE);
3034 
3035         /* lve claims to be GPL but upstream won't provide source */
3036         if (strcmp(mod->name, "lve") == 0)
3037                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3038                                  LOCKDEP_NOW_UNRELIABLE);
3039 
3040 #ifdef CONFIG_MODVERSIONS
3041         if ((mod->num_syms && !mod->crcs)
3042             || (mod->num_gpl_syms && !mod->gpl_crcs)
3043             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3044 #ifdef CONFIG_UNUSED_SYMBOLS
3045             || (mod->num_unused_syms && !mod->unused_crcs)
3046             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3047 #endif
3048                 ) {
3049                 return try_to_force_load(mod,
3050                                          "no versions for exported symbols");
3051         }
3052 #endif
3053         return 0;
3054 }
3055 
3056 static void flush_module_icache(const struct module *mod)
3057 {
3058         mm_segment_t old_fs;
3059 
3060         /* flush the icache in correct context */
3061         old_fs = get_fs();
3062         set_fs(KERNEL_DS);
3063 
3064         /*
3065          * Flush the instruction cache, since we've played with text.
3066          * Do it before processing of module parameters, so the module
3067          * can provide parameter accessor functions of its own.
3068          */
3069         if (mod->module_init)
3070                 flush_icache_range((unsigned long)mod->module_init,
3071                                    (unsigned long)mod->module_init
3072                                    + mod->init_size);
3073         flush_icache_range((unsigned long)mod->module_core,
3074                            (unsigned long)mod->module_core + mod->core_size);
3075 
3076         set_fs(old_fs);
3077 }
3078 
3079 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3080                                      Elf_Shdr *sechdrs,
3081                                      char *secstrings,
3082                                      struct module *mod)
3083 {
3084         return 0;
3085 }
3086 
3087 static struct module *layout_and_allocate(struct load_info *info, int flags)
3088 {
3089         /* Module within temporary copy. */
3090         struct module *mod;
3091         int err;
3092 
3093         mod = setup_load_info(info, flags);
3094         if (IS_ERR(mod))
3095                 return mod;
3096 
3097         err = check_modinfo(mod, info, flags);
3098         if (err)
3099                 return ERR_PTR(err);
3100 
3101         /* Allow arches to frob section contents and sizes.  */
3102         err = module_frob_arch_sections(info->hdr, info->sechdrs,
3103                                         info->secstrings, mod);
3104         if (err < 0)
3105                 return ERR_PTR(err);
3106 
3107         /* We will do a special allocation for per-cpu sections later. */
3108         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3109 
3110         /* Determine total sizes, and put offsets in sh_entsize.  For now
3111            this is done generically; there doesn't appear to be any
3112            special cases for the architectures. */
3113         layout_sections(mod, info);
3114         layout_symtab(mod, info);
3115 
3116         /* Allocate and move to the final place */
3117         err = move_module(mod, info);
3118         if (err)
3119                 return ERR_PTR(err);
3120 
3121         /* Module has been copied to its final place now: return it. */
3122         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3123         kmemleak_load_module(mod, info);
3124         return mod;
3125 }
3126 
3127 /* mod is no longer valid after this! */
3128 static void module_deallocate(struct module *mod, struct load_info *info)
3129 {
3130         percpu_modfree(mod);
3131         module_arch_freeing_init(mod);
3132         module_memfree(mod->module_init);
3133         module_memfree(mod->module_core);
3134 }
3135 
3136 int __weak module_finalize(const Elf_Ehdr *hdr,
3137                            const Elf_Shdr *sechdrs,
3138                            struct module *me)
3139 {
3140         return 0;
3141 }
3142 
3143 static int post_relocation(struct module *mod, const struct load_info *info)
3144 {
3145         /* Sort exception table now relocations are done. */
3146         sort_extable(mod->extable, mod->extable + mod->num_exentries);
3147 
3148         /* Copy relocated percpu area over. */
3149         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3150                        info->sechdrs[info->index.pcpu].sh_size);
3151 
3152         /* Setup kallsyms-specific fields. */
3153         add_kallsyms(mod, info);
3154 
3155         /* Arch-specific module finalizing. */
3156         return module_finalize(info->hdr, info->sechdrs, mod);
3157 }
3158 
3159 /* Is this module of this name done loading?  No locks held. */
3160 static bool finished_loading(const char *name)
3161 {
3162         struct module *mod;
3163         bool ret;
3164 
3165         /*
3166          * The module_mutex should not be a heavily contended lock;
3167          * if we get the occasional sleep here, we'll go an extra iteration
3168          * in the wait_event_interruptible(), which is harmless.
3169          */
3170         sched_annotate_sleep();
3171         mutex_lock(&module_mutex);
3172         mod = find_module_all(name, strlen(name), true);
3173         ret = !mod || mod->state == MODULE_STATE_LIVE
3174                 || mod->state == MODULE_STATE_GOING;
3175         mutex_unlock(&module_mutex);
3176 
3177         return ret;
3178 }
3179 
3180 /* Call module constructors. */
3181 static void do_mod_ctors(struct module *mod)
3182 {
3183 #ifdef CONFIG_CONSTRUCTORS
3184         unsigned long i;
3185 
3186         for (i = 0; i < mod->num_ctors; i++)
3187                 mod->ctors[i]();
3188 #endif
3189 }
3190 
3191 /* For freeing module_init on success, in case kallsyms traversing */
3192 struct mod_initfree {
3193         struct rcu_head rcu;
3194         void *module_init;
3195 };
3196 
3197 static void do_free_init(struct rcu_head *head)
3198 {
3199         struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3200         module_memfree(m->module_init);
3201         kfree(m);
3202 }
3203 
3204 /*
3205  * This is where the real work happens.
3206  *
3207  * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3208  * helper command 'lx-symbols'.
3209  */
3210 static noinline int do_init_module(struct module *mod)
3211 {
3212         int ret = 0;
3213         struct mod_initfree *freeinit;
3214 
3215         freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3216         if (!freeinit) {
3217                 ret = -ENOMEM;
3218                 goto fail;
3219         }
3220         freeinit->module_init = mod->module_init;
3221 
3222         /*
3223          * We want to find out whether @mod uses async during init.  Clear
3224          * PF_USED_ASYNC.  async_schedule*() will set it.
3225          */
3226         current->flags &= ~PF_USED_ASYNC;
3227 
3228         do_mod_ctors(mod);
3229         /* Start the module */
3230         if (mod->init != NULL)
3231                 ret = do_one_initcall(mod->init);
3232         if (ret < 0) {
3233                 goto fail_free_freeinit;
3234         }
3235         if (ret > 0) {
3236                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3237                         "follow 0/-E convention\n"
3238                         "%s: loading module anyway...\n",
3239                         __func__, mod->name, ret, __func__);
3240                 dump_stack();
3241         }
3242 
3243         /* Now it's a first class citizen! */
3244         mod->state = MODULE_STATE_LIVE;
3245         blocking_notifier_call_chain(&module_notify_list,
3246                                      MODULE_STATE_LIVE, mod);
3247 
3248         /*
3249          * We need to finish all async code before the module init sequence
3250          * is done.  This has potential to deadlock.  For example, a newly
3251          * detected block device can trigger request_module() of the
3252          * default iosched from async probing task.  Once userland helper
3253          * reaches here, async_synchronize_full() will wait on the async
3254          * task waiting on request_module() and deadlock.
3255          *
3256          * This deadlock is avoided by perfomring async_synchronize_full()
3257          * iff module init queued any async jobs.  This isn't a full
3258          * solution as it will deadlock the same if module loading from
3259          * async jobs nests more than once; however, due to the various
3260          * constraints, this hack seems to be the best option for now.
3261          * Please refer to the following thread for details.
3262          *
3263          * http://thread.gmane.org/gmane.linux.kernel/1420814
3264          */
3265         if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3266                 async_synchronize_full();
3267 
3268         mutex_lock(&module_mutex);
3269         /* Drop initial reference. */
3270         module_put(mod);
3271         trim_init_extable(mod);
3272 #ifdef CONFIG_KALLSYMS
3273         mod->num_symtab = mod->core_num_syms;
3274         mod->symtab = mod->core_symtab;
3275         mod->strtab = mod->core_strtab;
3276 #endif
3277         mod_tree_remove_init(mod);
3278         unset_module_init_ro_nx(mod);
3279         module_arch_freeing_init(mod);
3280         mod->module_init = NULL;
3281         mod->init_size = 0;
3282         mod->init_ro_size = 0;
3283         mod->init_text_size = 0;
3284         /*
3285          * We want to free module_init, but be aware that kallsyms may be
3286          * walking this with preempt disabled.  In all the failure paths, we
3287          * call synchronize_sched(), but we don't want to slow down the success
3288          * path, so use actual RCU here.
3289          */
3290         call_rcu_sched(&freeinit->rcu, do_free_init);
3291         mutex_unlock(&module_mutex);
3292         wake_up_all(&module_wq);
3293 
3294         return 0;
3295 
3296 fail_free_freeinit:
3297         kfree(freeinit);
3298 fail:
3299         /* Try to protect us from buggy refcounters. */
3300         mod->state = MODULE_STATE_GOING;
3301         synchronize_sched();
3302         module_put(mod);
3303         blocking_notifier_call_chain(&module_notify_list,
3304                                      MODULE_STATE_GOING, mod);
3305         free_module(mod);
3306         wake_up_all(&module_wq);
3307         return ret;
3308 }
3309 
3310 static int may_init_module(void)
3311 {
3312         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3313                 return -EPERM;
3314 
3315         return 0;
3316 }
3317 
3318 /*
3319  * We try to place it in the list now to make sure it's unique before
3320  * we dedicate too many resources.  In particular, temporary percpu
3321  * memory exhaustion.
3322  */
3323 static int add_unformed_module(struct module *mod)
3324 {
3325         int err;
3326         struct module *old;
3327 
3328         mod->state = MODULE_STATE_UNFORMED;
3329 
3330 again:
3331         mutex_lock(&module_mutex);
3332         old = find_module_all(mod->name, strlen(mod->name), true);
3333         if (old != NULL) {
3334                 if (old->state == MODULE_STATE_COMING
3335                     || old->state == MODULE_STATE_UNFORMED) {
3336                         /* Wait in case it fails to load. */
3337                         mutex_unlock(&module_mutex);
3338                         err = wait_event_interruptible(module_wq,
3339                                                finished_loading(mod->name));
3340                         if (err)
3341                                 goto out_unlocked;
3342                         goto again;
3343                 }
3344                 err = -EEXIST;
3345                 goto out;
3346         }
3347         mod_update_bounds(mod);
3348         list_add_rcu(&mod->list, &modules);
3349         mod_tree_insert(mod);
3350         err = 0;
3351 
3352 out:
3353         mutex_unlock(&module_mutex);
3354 out_unlocked:
3355         return err;
3356 }
3357 
3358 static int complete_formation(struct module *mod, struct load_info *info)
3359 {
3360         int err;
3361 
3362         mutex_lock(&module_mutex);
3363 
3364         /* Find duplicate symbols (must be called under lock). */
3365         err = verify_export_symbols(mod);
3366         if (err < 0)
3367                 goto out;
3368 
3369         /* This relies on module_mutex for list integrity. */
3370         module_bug_finalize(info->hdr, info->sechdrs, mod);
3371 
3372         /* Set RO and NX regions for core */
3373         set_section_ro_nx(mod->module_core,
3374                                 mod->core_text_size,
3375                                 mod->core_ro_size,
3376                                 mod->core_size);
3377 
3378         /* Set RO and NX regions for init */
3379         set_section_ro_nx(mod->module_init,
3380                                 mod->init_text_size,
3381                                 mod->init_ro_size,
3382                                 mod->init_size);
3383 
3384         /* Mark state as coming so strong_try_module_get() ignores us,
3385          * but kallsyms etc. can see us. */
3386         mod->state = MODULE_STATE_COMING;
3387         mutex_unlock(&module_mutex);
3388 
3389         blocking_notifier_call_chain(&module_notify_list,
3390                                      MODULE_STATE_COMING, mod);
3391         return 0;
3392 
3393 out:
3394         mutex_unlock(&module_mutex);
3395         return err;
3396 }
3397 
3398 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3399                                    void *arg)
3400 {
3401         struct module *mod = arg;
3402         int ret;
3403 
3404         if (strcmp(param, "async_probe") == 0) {
3405                 mod->async_probe_requested = true;
3406                 return 0;
3407         }
3408 
3409         /* Check for magic 'dyndbg' arg */
3410         ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3411         if (ret != 0)
3412                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3413         return 0;
3414 }
3415 
3416 /* Allocate and load the module: note that size of section 0 is always
3417    zero, and we rely on this for optional sections. */
3418 static int load_module(struct load_info *info, const char __user *uargs,
3419                        int flags)
3420 {
3421         struct module *mod;
3422         long err;
3423         char *after_dashes;
3424 
3425         err = module_sig_check(info);
3426         if (err)
3427                 goto free_copy;
3428 
3429         err = elf_header_check(info);
3430         if (err)
3431                 goto free_copy;
3432 
3433         /* Figure out module layout, and allocate all the memory. */
3434         mod = layout_and_allocate(info, flags);
3435         if (IS_ERR(mod)) {
3436                 err = PTR_ERR(mod);
3437                 goto free_copy;
3438         }
3439 
3440         /* Reserve our place in the list. */
3441         err = add_unformed_module(mod);
3442         if (err)
3443                 goto free_module;
3444 
3445 #ifdef CONFIG_MODULE_SIG
3446         mod->sig_ok = info->sig_ok;
3447         if (!mod->sig_ok) {
3448                 pr_notice_once("%s: module verification failed: signature "
3449                                "and/or required key missing - tainting "
3450                                "kernel\n", mod->name);
3451                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3452         }
3453 #endif
3454 
3455         /* To avoid stressing percpu allocator, do this once we're unique. */
3456         err = percpu_modalloc(mod, info);
3457         if (err)
3458                 goto unlink_mod;
3459 
3460         /* Now module is in final location, initialize linked lists, etc. */
3461         err = module_unload_init(mod);
3462         if (err)
3463                 goto unlink_mod;
3464 
3465         init_param_lock(mod);
3466 
3467         /* Now we've got everything in the final locations, we can
3468          * find optional sections. */
3469         err = find_module_sections(mod, info);
3470         if (err)
3471                 goto free_unload;
3472 
3473         err = check_module_license_and_versions(mod);
3474         if (err)
3475                 goto free_unload;
3476 
3477         /* Set up MODINFO_ATTR fields */
3478         setup_modinfo(mod, info);
3479 
3480         /* Fix up syms, so that st_value is a pointer to location. */
3481         err = simplify_symbols(mod, info);
3482         if (err < 0)
3483                 goto free_modinfo;
3484 
3485         err = apply_relocations(mod, info);
3486         if (err < 0)
3487                 goto free_modinfo;
3488 
3489         err = post_relocation(mod, info);
3490         if (err < 0)
3491                 goto free_modinfo;
3492 
3493         flush_module_icache(mod);
3494 
3495         /* Now copy in args */
3496         mod->args = strndup_user(uargs, ~0UL >> 1);
3497         if (IS_ERR(mod->args)) {
3498                 err = PTR_ERR(mod->args);
3499                 goto free_arch_cleanup;
3500         }
3501 
3502         dynamic_debug_setup(info->debug, info->num_debug);
3503 
3504         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3505         ftrace_module_init(mod);
3506 
3507         /* Finally it's fully formed, ready to start executing. */
3508         err = complete_formation(mod, info);
3509         if (err)
3510                 goto ddebug_cleanup;
3511 
3512         /* Module is ready to execute: parsing args may do that. */
3513         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3514                                   -32768, 32767, NULL,
3515                                   unknown_module_param_cb);
3516         if (IS_ERR(after_dashes)) {
3517                 err = PTR_ERR(after_dashes);
3518                 goto bug_cleanup;
3519         } else if (after_dashes) {
3520                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3521                        mod->name, after_dashes);
3522         }
3523 
3524         /* Link in to syfs. */
3525         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3526         if (err < 0)
3527                 goto bug_cleanup;
3528 
3529         /* Get rid of temporary copy. */
3530         free_copy(info);
3531 
3532         /* Done! */
3533         trace_module_load(mod);
3534 
3535         return do_init_module(mod);
3536 
3537  bug_cleanup:
3538         /* module_bug_cleanup needs module_mutex protection */
3539         mutex_lock(&module_mutex);
3540         module_bug_cleanup(mod);
3541         mutex_unlock(&module_mutex);
3542 
3543         blocking_notifier_call_chain(&module_notify_list,
3544                                      MODULE_STATE_GOING, mod);
3545 
3546         /* we can't deallocate the module until we clear memory protection */
3547         unset_module_init_ro_nx(mod);
3548         unset_module_core_ro_nx(mod);
3549 
3550  ddebug_cleanup:
3551         dynamic_debug_remove(info->debug);
3552         synchronize_sched();
3553         kfree(mod->args);
3554  free_arch_cleanup:
3555         module_arch_cleanup(mod);
3556  free_modinfo:
3557         free_modinfo(mod);
3558  free_unload:
3559         module_unload_free(mod);
3560  unlink_mod:
3561         mutex_lock(&module_mutex);
3562         /* Unlink carefully: kallsyms could be walking list. */
3563         list_del_rcu(&mod->list);
3564         mod_tree_remove(mod);
3565         wake_up_all(&module_wq);
3566         /* Wait for RCU-sched synchronizing before releasing mod->list. */
3567         synchronize_sched();
3568         mutex_unlock(&module_mutex);
3569  free_module:
3570         /* Free lock-classes; relies on the preceding sync_rcu() */
3571         lockdep_free_key_range(mod->module_core, mod->core_size);
3572 
3573         module_deallocate(mod, info);
3574  free_copy:
3575         free_copy(info);
3576         return err;
3577 }
3578 
3579 SYSCALL_DEFINE3(init_module, void __user *, umod,
3580                 unsigned long, len, const char __user *, uargs)
3581 {
3582         int err;
3583         struct load_info info = { };
3584 
3585         err = may_init_module();
3586         if (err)
3587                 return err;
3588 
3589         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3590                umod, len, uargs);
3591 
3592         err = copy_module_from_user(umod, len, &info);
3593         if (err)
3594                 return err;
3595 
3596         return load_module(&info, uargs, 0);
3597 }
3598 
3599 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3600 {
3601         int err;
3602         struct load_info info = { };
3603 
3604         err = may_init_module();
3605         if (err)
3606                 return err;
3607 
3608         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3609 
3610         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3611                       |MODULE_INIT_IGNORE_VERMAGIC))
3612                 return -EINVAL;
3613 
3614         err = copy_module_from_fd(fd, &info);
3615         if (err)
3616                 return err;
3617 
3618         return load_module(&info, uargs, flags);
3619 }
3620 
3621 static inline int within(unsigned long addr, void *start, unsigned long size)
3622 {
3623         return ((void *)addr >= start && (void *)addr < start + size);
3624 }
3625 
3626 #ifdef CONFIG_KALLSYMS
3627 /*
3628  * This ignores the intensely annoying "mapping symbols" found
3629  * in ARM ELF files: $a, $t and $d.
3630  */
3631 static inline int is_arm_mapping_symbol(const char *str)
3632 {
3633         if (str[0] == '.' && str[1] == 'L')
3634                 return true;
3635         return str[0] == '$' && strchr("axtd", str[1])
3636                && (str[2] == '\0' || str[2] == '.');
3637 }
3638 
3639 static const char *get_ksymbol(struct module *mod,
3640                                unsigned long addr,
3641                                unsigned long *size,
3642                                unsigned long *offset)
3643 {
3644         unsigned int i, best = 0;
3645         unsigned long nextval;
3646 
3647         /* At worse, next value is at end of module */
3648         if (within_module_init(addr, mod))
3649                 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3650         else
3651                 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3652 
3653         /* Scan for closest preceding symbol, and next symbol. (ELF
3654            starts real symbols at 1). */
3655         for (i = 1; i < mod->num_symtab; i++) {
3656                 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3657                         continue;
3658 
3659                 /* We ignore unnamed symbols: they're uninformative
3660                  * and inserted at a whim. */
3661                 if (mod->symtab[i].st_value <= addr
3662                     && mod->symtab[i].st_value > mod->symtab[best].st_value
3663                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3664                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3665                         best = i;
3666                 if (mod->symtab[i].st_value > addr
3667                     && mod->symtab[i].st_value < nextval
3668                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3669                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3670                         nextval = mod->symtab[i].st_value;
3671         }
3672 
3673         if (!best)
3674                 return NULL;
3675 
3676         if (size)
3677                 *size = nextval - mod->symtab[best].st_value;
3678         if (offset)
3679                 *offset = addr - mod->symtab[best].st_value;
3680         return mod->strtab + mod->symtab[best].st_name;
3681 }
3682 
3683 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3684  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3685 const char *module_address_lookup(unsigned long addr,
3686                             unsigned long *size,
3687                             unsigned long *offset,
3688                             char **modname,
3689                             char *namebuf)
3690 {
3691         const char *ret = NULL;
3692         struct module *mod;
3693 
3694         preempt_disable();
3695         mod = __module_address(addr);
3696         if (mod) {
3697                 if (modname)
3698                         *modname = mod->name;
3699                 ret = get_ksymbol(mod, addr, size, offset);
3700         }
3701         /* Make a copy in here where it's safe */
3702         if (ret) {
3703                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3704                 ret = namebuf;
3705         }
3706         preempt_enable();
3707 
3708         return ret;
3709 }
3710 
3711 int lookup_module_symbol_name(unsigned long addr, char *symname)
3712 {
3713         struct module *mod;
3714 
3715         preempt_disable();
3716         list_for_each_entry_rcu(mod, &modules, list) {
3717                 if (mod->state == MODULE_STATE_UNFORMED)
3718                         continue;
3719                 if (within_module(addr, mod)) {
3720                         const char *sym;
3721 
3722                         sym = get_ksymbol(mod, addr, NULL, NULL);
3723                         if (!sym)
3724                                 goto out;
3725                         strlcpy(symname, sym, KSYM_NAME_LEN);
3726                         preempt_enable();
3727                         return 0;
3728                 }
3729         }
3730 out:
3731         preempt_enable();
3732         return -ERANGE;
3733 }
3734 
3735 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3736                         unsigned long *offset, char *modname, char *name)
3737 {
3738         struct module *mod;
3739 
3740         preempt_disable();
3741         list_for_each_entry_rcu(mod, &modules, list) {
3742                 if (mod->state == MODULE_STATE_UNFORMED)
3743                         continue;
3744                 if (within_module(addr, mod)) {
3745                         const char *sym;
3746 
3747                         sym = get_ksymbol(mod, addr, size, offset);
3748                         if (!sym)
3749                                 goto out;
3750                         if (modname)
3751                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3752                         if (name)
3753                                 strlcpy(name, sym, KSYM_NAME_LEN);
3754                         preempt_enable();
3755                         return 0;
3756                 }
3757         }
3758 out:
3759         preempt_enable();
3760         return -ERANGE;
3761 }
3762 
3763 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3764                         char *name, char *module_name, int *exported)
3765 {
3766         struct module *mod;
3767 
3768         preempt_disable();
3769         list_for_each_entry_rcu(mod, &modules, list) {
3770                 if (mod->state == MODULE_STATE_UNFORMED)
3771                         continue;
3772                 if (symnum < mod->num_symtab) {
3773                         *value = mod->symtab[symnum].st_value;
3774                         *type = mod->symtab[symnum].st_info;
3775                         strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3776                                 KSYM_NAME_LEN);
3777                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3778                         *exported = is_exported(name, *value, mod);
3779                         preempt_enable();
3780                         return 0;
3781                 }
3782                 symnum -= mod->num_symtab;
3783         }
3784         preempt_enable();
3785         return -ERANGE;
3786 }
3787 
3788 static unsigned long mod_find_symname(struct module *mod, const char *name)
3789 {
3790         unsigned int i;
3791 
3792         for (i = 0; i < mod->num_symtab; i++)
3793                 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3794                     mod->symtab[i].st_info != 'U')
3795                         return mod->symtab[i].st_value;
3796         return 0;
3797 }
3798 
3799 /* Look for this name: can be of form module:name. */
3800 unsigned long module_kallsyms_lookup_name(const char *name)
3801 {
3802         struct module *mod;
3803         char *colon;
3804         unsigned long ret = 0;
3805 
3806         /* Don't lock: we're in enough trouble already. */
3807         preempt_disable();
3808         if ((colon = strchr(name, ':')) != NULL) {
3809                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3810                         ret = mod_find_symname(mod, colon+1);
3811         } else {
3812                 list_for_each_entry_rcu(mod, &modules, list) {
3813                         if (mod->state == MODULE_STATE_UNFORMED)
3814                                 continue;
3815                         if ((ret = mod_find_symname(mod, name)) != 0)
3816                                 break;
3817                 }
3818         }
3819         preempt_enable();
3820         return ret;
3821 }
3822 
3823 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3824                                              struct module *, unsigned long),
3825                                    void *data)
3826 {
3827         struct module *mod;
3828         unsigned int i;
3829         int ret;
3830 
3831         module_assert_mutex();
3832 
3833         list_for_each_entry(mod, &modules, list) {
3834                 if (mod->state == MODULE_STATE_UNFORMED)
3835                         continue;
3836                 for (i = 0; i < mod->num_symtab; i++) {
3837                         ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3838                                  mod, mod->symtab[i].st_value);
3839                         if (ret != 0)
3840                                 return ret;
3841                 }
3842         }
3843         return 0;
3844 }
3845 #endif /* CONFIG_KALLSYMS */
3846 
3847 static char *module_flags(struct module *mod, char *buf)
3848 {
3849         int bx = 0;
3850 
3851         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3852         if (mod->taints ||
3853             mod->state == MODULE_STATE_GOING ||
3854             mod->state == MODULE_STATE_COMING) {
3855                 buf[bx++] = '(';
3856                 bx += module_flags_taint(mod, buf + bx);
3857                 /* Show a - for module-is-being-unloaded */
3858                 if (mod->state == MODULE_STATE_GOING)
3859                         buf[bx++] = '-';
3860                 /* Show a + for module-is-being-loaded */
3861                 if (mod->state == MODULE_STATE_COMING)
3862                         buf[bx++] = '+';
3863                 buf[bx++] = ')';
3864         }
3865         buf[bx] = '\0';
3866 
3867         return buf;
3868 }
3869 
3870 #ifdef CONFIG_PROC_FS
3871 /* Called by the /proc file system to return a list of modules. */
3872 static void *m_start(struct seq_file *m, loff_t *pos)
3873 {
3874         mutex_lock(&module_mutex);
3875         return seq_list_start(&modules, *pos);
3876 }
3877 
3878 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3879 {
3880         return seq_list_next(p, &modules, pos);
3881 }
3882 
3883 static void m_stop(struct seq_file *m, void *p)
3884 {
3885         mutex_unlock(&module_mutex);
3886 }
3887 
3888 static int m_show(struct seq_file *m, void *p)
3889 {
3890         struct module *mod = list_entry(p, struct module, list);
3891         char buf[8];
3892 
3893         /* We always ignore unformed modules. */
3894         if (mod->state == MODULE_STATE_UNFORMED)
3895                 return 0;
3896 
3897         seq_printf(m, "%s %u",
3898                    mod->name, mod->init_size + mod->core_size);
3899         print_unload_info(m, mod);
3900 
3901         /* Informative for users. */
3902         seq_printf(m, " %s",
3903                    mod->state == MODULE_STATE_GOING ? "Unloading" :
3904                    mod->state == MODULE_STATE_COMING ? "Loading" :
3905                    "Live");
3906         /* Used by oprofile and other similar tools. */
3907         seq_printf(m, " 0x%pK", mod->module_core);
3908 
3909         /* Taints info */
3910         if (mod->taints)
3911                 seq_printf(m, " %s", module_flags(mod, buf));
3912 
3913         seq_puts(m, "\n");
3914         return 0;
3915 }
3916 
3917 /* Format: modulename size refcount deps address
3918 
3919    Where refcount is a number or -, and deps is a comma-separated list
3920    of depends or -.
3921 */
3922 static const struct seq_operations modules_op = {
3923         .start  = m_start,
3924         .next   = m_next,
3925         .stop   = m_stop,
3926         .show   = m_show
3927 };
3928 
3929 static int modules_open(struct inode *inode, struct file *file)
3930 {
3931         return seq_open(file, &modules_op);
3932 }
3933 
3934 static const struct file_operations proc_modules_operations = {
3935         .open           = modules_open,
3936         .read           = seq_read,
3937         .llseek         = seq_lseek,
3938         .release        = seq_release,
3939 };
3940 
3941 static int __init proc_modules_init(void)
3942 {
3943         proc_create("modules", 0, NULL, &proc_modules_operations);
3944         return 0;
3945 }
3946 module_init(proc_modules_init);
3947 #endif
3948 
3949 /* Given an address, look for it in the module exception tables. */
3950 const struct exception_table_entry *search_module_extables(unsigned long addr)
3951 {
3952         const struct exception_table_entry *e = NULL;
3953         struct module *mod;
3954 
3955         preempt_disable();
3956         list_for_each_entry_rcu(mod, &modules, list) {
3957                 if (mod->state == MODULE_STATE_UNFORMED)
3958                         continue;
3959                 if (mod->num_exentries == 0)
3960                         continue;
3961 
3962                 e = search_extable(mod->extable,
3963                                    mod->extable + mod->num_exentries - 1,
3964                                    addr);
3965                 if (e)
3966                         break;
3967         }
3968         preempt_enable();
3969 
3970         /* Now, if we found one, we are running inside it now, hence
3971            we cannot unload the module, hence no refcnt needed. */
3972         return e;
3973 }
3974 
3975 /*
3976  * is_module_address - is this address inside a module?
3977  * @addr: the address to check.
3978  *
3979  * See is_module_text_address() if you simply want to see if the address
3980  * is code (not data).
3981  */
3982 bool is_module_address(unsigned long addr)
3983 {
3984         bool ret;
3985 
3986         preempt_disable();
3987         ret = __module_address(addr) != NULL;
3988         preempt_enable();
3989 
3990         return ret;
3991 }
3992 
3993 /*
3994  * __module_address - get the module which contains an address.
3995  * @addr: the address.
3996  *
3997  * Must be called with preempt disabled or module mutex held so that
3998  * module doesn't get freed during this.
3999  */
4000 struct module *__module_address(unsigned long addr)
4001 {
4002         struct module *mod;
4003 
4004         if (addr < module_addr_min || addr > module_addr_max)
4005                 return NULL;
4006 
4007         module_assert_mutex_or_preempt();
4008 
4009         mod = mod_find(addr);
4010         if (mod) {
4011                 BUG_ON(!within_module(addr, mod));
4012                 if (mod->state == MODULE_STATE_UNFORMED)
4013                         mod = NULL;
4014         }
4015         return mod;
4016 }
4017 EXPORT_SYMBOL_GPL(__module_address);
4018 
4019 /*
4020  * is_module_text_address - is this address inside module code?
4021  * @addr: the address to check.
4022  *
4023  * See is_module_address() if you simply want to see if the address is
4024  * anywhere in a module.  See kernel_text_address() for testing if an
4025  * address corresponds to kernel or module code.
4026  */
4027 bool is_module_text_address(unsigned long addr)
4028 {
4029         bool ret;
4030 
4031         preempt_disable();
4032         ret = __module_text_address(addr) != NULL;
4033         preempt_enable();
4034 
4035         return ret;
4036 }
4037 
4038 /*
4039  * __module_text_address - get the module whose code contains an address.
4040  * @addr: the address.
4041  *
4042  * Must be called with preempt disabled or module mutex held so that
4043  * module doesn't get freed during this.
4044  */
4045 struct module *__module_text_address(unsigned long addr)
4046 {
4047         struct module *mod = __module_address(addr);
4048         if (mod) {
4049                 /* Make sure it's within the text section. */
4050                 if (!within(addr, mod->module_init, mod->init_text_size)
4051                     && !within(addr, mod->module_core, mod->core_text_size))
4052                         mod = NULL;
4053         }
4054         return mod;
4055 }
4056 EXPORT_SYMBOL_GPL(__module_text_address);
4057 
4058 /* Don't grab lock, we're oopsing. */
4059 void print_modules(void)
4060 {
4061         struct module *mod;
4062         char buf[8];
4063 
4064         printk(KERN_DEFAULT "Modules linked in:");
4065         /* Most callers should already have preempt disabled, but make sure */
4066         preempt_disable();
4067         list_for_each_entry_rcu(mod, &modules, list) {
4068                 if (mod->state == MODULE_STATE_UNFORMED)
4069                         continue;
4070                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4071         }
4072         preempt_enable();
4073         if (last_unloaded_module[0])
4074                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4075         pr_cont("\n");
4076 }
4077 
4078 #ifdef CONFIG_MODVERSIONS
4079 /* Generate the signature for all relevant module structures here.
4080  * If these change, we don't want to try to parse the module. */
4081 void module_layout(struct module *mod,
4082                    struct modversion_info *ver,
4083                    struct kernel_param *kp,
4084                    struct kernel_symbol *ks,
4085                    struct tracepoint * const *tp)
4086 {
4087 }
4088 EXPORT_SYMBOL(module_layout);
4089 #endif
4090 

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