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

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         /*
1067          * Even though we hold a reference on the module; we still need to
1068          * disable preemption in order to safely traverse the data structure.
1069          */
1070         preempt_disable();
1071         modaddr = __module_text_address(a);
1072         BUG_ON(!modaddr);
1073         module_put(modaddr);
1074         preempt_enable();
1075 }
1076 EXPORT_SYMBOL_GPL(symbol_put_addr);
1077 
1078 static ssize_t show_refcnt(struct module_attribute *mattr,
1079                            struct module_kobject *mk, char *buffer)
1080 {
1081         return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1082 }
1083 
1084 static struct module_attribute modinfo_refcnt =
1085         __ATTR(refcnt, 0444, show_refcnt, NULL);
1086 
1087 void __module_get(struct module *module)
1088 {
1089         if (module) {
1090                 preempt_disable();
1091                 atomic_inc(&module->refcnt);
1092                 trace_module_get(module, _RET_IP_);
1093                 preempt_enable();
1094         }
1095 }
1096 EXPORT_SYMBOL(__module_get);
1097 
1098 bool try_module_get(struct module *module)
1099 {
1100         bool ret = true;
1101 
1102         if (module) {
1103                 preempt_disable();
1104                 /* Note: here, we can fail to get a reference */
1105                 if (likely(module_is_live(module) &&
1106                            atomic_inc_not_zero(&module->refcnt) != 0))
1107                         trace_module_get(module, _RET_IP_);
1108                 else
1109                         ret = false;
1110 
1111                 preempt_enable();
1112         }
1113         return ret;
1114 }
1115 EXPORT_SYMBOL(try_module_get);
1116 
1117 void module_put(struct module *module)
1118 {
1119         int ret;
1120 
1121         if (module) {
1122                 preempt_disable();
1123                 ret = atomic_dec_if_positive(&module->refcnt);
1124                 WARN_ON(ret < 0);       /* Failed to put refcount */
1125                 trace_module_put(module, _RET_IP_);
1126                 preempt_enable();
1127         }
1128 }
1129 EXPORT_SYMBOL(module_put);
1130 
1131 #else /* !CONFIG_MODULE_UNLOAD */
1132 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1133 {
1134         /* We don't know the usage count, or what modules are using. */
1135         seq_puts(m, " - -");
1136 }
1137 
1138 static inline void module_unload_free(struct module *mod)
1139 {
1140 }
1141 
1142 int ref_module(struct module *a, struct module *b)
1143 {
1144         return strong_try_module_get(b);
1145 }
1146 EXPORT_SYMBOL_GPL(ref_module);
1147 
1148 static inline int module_unload_init(struct module *mod)
1149 {
1150         return 0;
1151 }
1152 #endif /* CONFIG_MODULE_UNLOAD */
1153 
1154 static size_t module_flags_taint(struct module *mod, char *buf)
1155 {
1156         size_t l = 0;
1157 
1158         if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1159                 buf[l++] = 'P';
1160         if (mod->taints & (1 << TAINT_OOT_MODULE))
1161                 buf[l++] = 'O';
1162         if (mod->taints & (1 << TAINT_FORCED_MODULE))
1163                 buf[l++] = 'F';
1164         if (mod->taints & (1 << TAINT_CRAP))
1165                 buf[l++] = 'C';
1166         if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1167                 buf[l++] = 'E';
1168         /*
1169          * TAINT_FORCED_RMMOD: could be added.
1170          * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1171          * apply to modules.
1172          */
1173         return l;
1174 }
1175 
1176 static ssize_t show_initstate(struct module_attribute *mattr,
1177                               struct module_kobject *mk, char *buffer)
1178 {
1179         const char *state = "unknown";
1180 
1181         switch (mk->mod->state) {
1182         case MODULE_STATE_LIVE:
1183                 state = "live";
1184                 break;
1185         case MODULE_STATE_COMING:
1186                 state = "coming";
1187                 break;
1188         case MODULE_STATE_GOING:
1189                 state = "going";
1190                 break;
1191         default:
1192                 BUG();
1193         }
1194         return sprintf(buffer, "%s\n", state);
1195 }
1196 
1197 static struct module_attribute modinfo_initstate =
1198         __ATTR(initstate, 0444, show_initstate, NULL);
1199 
1200 static ssize_t store_uevent(struct module_attribute *mattr,
1201                             struct module_kobject *mk,
1202                             const char *buffer, size_t count)
1203 {
1204         enum kobject_action action;
1205 
1206         if (kobject_action_type(buffer, count, &action) == 0)
1207                 kobject_uevent(&mk->kobj, action);
1208         return count;
1209 }
1210 
1211 struct module_attribute module_uevent =
1212         __ATTR(uevent, 0200, NULL, store_uevent);
1213 
1214 static ssize_t show_coresize(struct module_attribute *mattr,
1215                              struct module_kobject *mk, char *buffer)
1216 {
1217         return sprintf(buffer, "%u\n", mk->mod->core_size);
1218 }
1219 
1220 static struct module_attribute modinfo_coresize =
1221         __ATTR(coresize, 0444, show_coresize, NULL);
1222 
1223 static ssize_t show_initsize(struct module_attribute *mattr,
1224                              struct module_kobject *mk, char *buffer)
1225 {
1226         return sprintf(buffer, "%u\n", mk->mod->init_size);
1227 }
1228 
1229 static struct module_attribute modinfo_initsize =
1230         __ATTR(initsize, 0444, show_initsize, NULL);
1231 
1232 static ssize_t show_taint(struct module_attribute *mattr,
1233                           struct module_kobject *mk, char *buffer)
1234 {
1235         size_t l;
1236 
1237         l = module_flags_taint(mk->mod, buffer);
1238         buffer[l++] = '\n';
1239         return l;
1240 }
1241 
1242 static struct module_attribute modinfo_taint =
1243         __ATTR(taint, 0444, show_taint, NULL);
1244 
1245 static struct module_attribute *modinfo_attrs[] = {
1246         &module_uevent,
1247         &modinfo_version,
1248         &modinfo_srcversion,
1249         &modinfo_initstate,
1250         &modinfo_coresize,
1251         &modinfo_initsize,
1252         &modinfo_taint,
1253 #ifdef CONFIG_MODULE_UNLOAD
1254         &modinfo_refcnt,
1255 #endif
1256         NULL,
1257 };
1258 
1259 static const char vermagic[] = VERMAGIC_STRING;
1260 
1261 static int try_to_force_load(struct module *mod, const char *reason)
1262 {
1263 #ifdef CONFIG_MODULE_FORCE_LOAD
1264         if (!test_taint(TAINT_FORCED_MODULE))
1265                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1266         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1267         return 0;
1268 #else
1269         return -ENOEXEC;
1270 #endif
1271 }
1272 
1273 #ifdef CONFIG_MODVERSIONS
1274 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1275 static unsigned long maybe_relocated(unsigned long crc,
1276                                      const struct module *crc_owner)
1277 {
1278 #ifdef ARCH_RELOCATES_KCRCTAB
1279         if (crc_owner == NULL)
1280                 return crc - (unsigned long)reloc_start;
1281 #endif
1282         return crc;
1283 }
1284 
1285 static int check_version(Elf_Shdr *sechdrs,
1286                          unsigned int versindex,
1287                          const char *symname,
1288                          struct module *mod,
1289                          const unsigned long *crc,
1290                          const struct module *crc_owner)
1291 {
1292         unsigned int i, num_versions;
1293         struct modversion_info *versions;
1294 
1295         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1296         if (!crc)
1297                 return 1;
1298 
1299         /* No versions at all?  modprobe --force does this. */
1300         if (versindex == 0)
1301                 return try_to_force_load(mod, symname) == 0;
1302 
1303         versions = (void *) sechdrs[versindex].sh_addr;
1304         num_versions = sechdrs[versindex].sh_size
1305                 / sizeof(struct modversion_info);
1306 
1307         for (i = 0; i < num_versions; i++) {
1308                 if (strcmp(versions[i].name, symname) != 0)
1309                         continue;
1310 
1311                 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1312                         return 1;
1313                 pr_debug("Found checksum %lX vs module %lX\n",
1314                        maybe_relocated(*crc, crc_owner), versions[i].crc);
1315                 goto bad_version;
1316         }
1317 
1318         pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1319         return 0;
1320 
1321 bad_version:
1322         pr_warn("%s: disagrees about version of symbol %s\n",
1323                mod->name, symname);
1324         return 0;
1325 }
1326 
1327 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1328                                           unsigned int versindex,
1329                                           struct module *mod)
1330 {
1331         const unsigned long *crc;
1332 
1333         /*
1334          * Since this should be found in kernel (which can't be removed), no
1335          * locking is necessary -- use preempt_disable() to placate lockdep.
1336          */
1337         preempt_disable();
1338         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1339                          &crc, true, false)) {
1340                 preempt_enable();
1341                 BUG();
1342         }
1343         preempt_enable();
1344         return check_version(sechdrs, versindex,
1345                              VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1346                              NULL);
1347 }
1348 
1349 /* First part is kernel version, which we ignore if module has crcs. */
1350 static inline int same_magic(const char *amagic, const char *bmagic,
1351                              bool has_crcs)
1352 {
1353         if (has_crcs) {
1354                 amagic += strcspn(amagic, " ");
1355                 bmagic += strcspn(bmagic, " ");
1356         }
1357         return strcmp(amagic, bmagic) == 0;
1358 }
1359 #else
1360 static inline int check_version(Elf_Shdr *sechdrs,
1361                                 unsigned int versindex,
1362                                 const char *symname,
1363                                 struct module *mod,
1364                                 const unsigned long *crc,
1365                                 const struct module *crc_owner)
1366 {
1367         return 1;
1368 }
1369 
1370 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1371                                           unsigned int versindex,
1372                                           struct module *mod)
1373 {
1374         return 1;
1375 }
1376 
1377 static inline int same_magic(const char *amagic, const char *bmagic,
1378                              bool has_crcs)
1379 {
1380         return strcmp(amagic, bmagic) == 0;
1381 }
1382 #endif /* CONFIG_MODVERSIONS */
1383 
1384 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1385 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1386                                                   const struct load_info *info,
1387                                                   const char *name,
1388                                                   char ownername[])
1389 {
1390         struct module *owner;
1391         const struct kernel_symbol *sym;
1392         const unsigned long *crc;
1393         int err;
1394 
1395         /*
1396          * The module_mutex should not be a heavily contended lock;
1397          * if we get the occasional sleep here, we'll go an extra iteration
1398          * in the wait_event_interruptible(), which is harmless.
1399          */
1400         sched_annotate_sleep();
1401         mutex_lock(&module_mutex);
1402         sym = find_symbol(name, &owner, &crc,
1403                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1404         if (!sym)
1405                 goto unlock;
1406 
1407         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1408                            owner)) {
1409                 sym = ERR_PTR(-EINVAL);
1410                 goto getname;
1411         }
1412 
1413         err = ref_module(mod, owner);
1414         if (err) {
1415                 sym = ERR_PTR(err);
1416                 goto getname;
1417         }
1418 
1419 getname:
1420         /* We must make copy under the lock if we failed to get ref. */
1421         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1422 unlock:
1423         mutex_unlock(&module_mutex);
1424         return sym;
1425 }
1426 
1427 static const struct kernel_symbol *
1428 resolve_symbol_wait(struct module *mod,
1429                     const struct load_info *info,
1430                     const char *name)
1431 {
1432         const struct kernel_symbol *ksym;
1433         char owner[MODULE_NAME_LEN];
1434 
1435         if (wait_event_interruptible_timeout(module_wq,
1436                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1437                         || PTR_ERR(ksym) != -EBUSY,
1438                                              30 * HZ) <= 0) {
1439                 pr_warn("%s: gave up waiting for init of module %s.\n",
1440                         mod->name, owner);
1441         }
1442         return ksym;
1443 }
1444 
1445 /*
1446  * /sys/module/foo/sections stuff
1447  * J. Corbet <corbet@lwn.net>
1448  */
1449 #ifdef CONFIG_SYSFS
1450 
1451 #ifdef CONFIG_KALLSYMS
1452 static inline bool sect_empty(const Elf_Shdr *sect)
1453 {
1454         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1455 }
1456 
1457 struct module_sect_attr {
1458         struct module_attribute mattr;
1459         char *name;
1460         unsigned long address;
1461 };
1462 
1463 struct module_sect_attrs {
1464         struct attribute_group grp;
1465         unsigned int nsections;
1466         struct module_sect_attr attrs[0];
1467 };
1468 
1469 static ssize_t module_sect_show(struct module_attribute *mattr,
1470                                 struct module_kobject *mk, char *buf)
1471 {
1472         struct module_sect_attr *sattr =
1473                 container_of(mattr, struct module_sect_attr, mattr);
1474         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1475 }
1476 
1477 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1478 {
1479         unsigned int section;
1480 
1481         for (section = 0; section < sect_attrs->nsections; section++)
1482                 kfree(sect_attrs->attrs[section].name);
1483         kfree(sect_attrs);
1484 }
1485 
1486 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1487 {
1488         unsigned int nloaded = 0, i, size[2];
1489         struct module_sect_attrs *sect_attrs;
1490         struct module_sect_attr *sattr;
1491         struct attribute **gattr;
1492 
1493         /* Count loaded sections and allocate structures */
1494         for (i = 0; i < info->hdr->e_shnum; i++)
1495                 if (!sect_empty(&info->sechdrs[i]))
1496                         nloaded++;
1497         size[0] = ALIGN(sizeof(*sect_attrs)
1498                         + nloaded * sizeof(sect_attrs->attrs[0]),
1499                         sizeof(sect_attrs->grp.attrs[0]));
1500         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1501         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1502         if (sect_attrs == NULL)
1503                 return;
1504 
1505         /* Setup section attributes. */
1506         sect_attrs->grp.name = "sections";
1507         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1508 
1509         sect_attrs->nsections = 0;
1510         sattr = &sect_attrs->attrs[0];
1511         gattr = &sect_attrs->grp.attrs[0];
1512         for (i = 0; i < info->hdr->e_shnum; i++) {
1513                 Elf_Shdr *sec = &info->sechdrs[i];
1514                 if (sect_empty(sec))
1515                         continue;
1516                 sattr->address = sec->sh_addr;
1517                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1518                                         GFP_KERNEL);
1519                 if (sattr->name == NULL)
1520                         goto out;
1521                 sect_attrs->nsections++;
1522                 sysfs_attr_init(&sattr->mattr.attr);
1523                 sattr->mattr.show = module_sect_show;
1524                 sattr->mattr.store = NULL;
1525                 sattr->mattr.attr.name = sattr->name;
1526                 sattr->mattr.attr.mode = S_IRUGO;
1527                 *(gattr++) = &(sattr++)->mattr.attr;
1528         }
1529         *gattr = NULL;
1530 
1531         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1532                 goto out;
1533 
1534         mod->sect_attrs = sect_attrs;
1535         return;
1536   out:
1537         free_sect_attrs(sect_attrs);
1538 }
1539 
1540 static void remove_sect_attrs(struct module *mod)
1541 {
1542         if (mod->sect_attrs) {
1543                 sysfs_remove_group(&mod->mkobj.kobj,
1544                                    &mod->sect_attrs->grp);
1545                 /* We are positive that no one is using any sect attrs
1546                  * at this point.  Deallocate immediately. */
1547                 free_sect_attrs(mod->sect_attrs);
1548                 mod->sect_attrs = NULL;
1549         }
1550 }
1551 
1552 /*
1553  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1554  */
1555 
1556 struct module_notes_attrs {
1557         struct kobject *dir;
1558         unsigned int notes;
1559         struct bin_attribute attrs[0];
1560 };
1561 
1562 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1563                                  struct bin_attribute *bin_attr,
1564                                  char *buf, loff_t pos, size_t count)
1565 {
1566         /*
1567          * The caller checked the pos and count against our size.
1568          */
1569         memcpy(buf, bin_attr->private + pos, count);
1570         return count;
1571 }
1572 
1573 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1574                              unsigned int i)
1575 {
1576         if (notes_attrs->dir) {
1577                 while (i-- > 0)
1578                         sysfs_remove_bin_file(notes_attrs->dir,
1579                                               &notes_attrs->attrs[i]);
1580                 kobject_put(notes_attrs->dir);
1581         }
1582         kfree(notes_attrs);
1583 }
1584 
1585 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1586 {
1587         unsigned int notes, loaded, i;
1588         struct module_notes_attrs *notes_attrs;
1589         struct bin_attribute *nattr;
1590 
1591         /* failed to create section attributes, so can't create notes */
1592         if (!mod->sect_attrs)
1593                 return;
1594 
1595         /* Count notes sections and allocate structures.  */
1596         notes = 0;
1597         for (i = 0; i < info->hdr->e_shnum; i++)
1598                 if (!sect_empty(&info->sechdrs[i]) &&
1599                     (info->sechdrs[i].sh_type == SHT_NOTE))
1600                         ++notes;
1601 
1602         if (notes == 0)
1603                 return;
1604 
1605         notes_attrs = kzalloc(sizeof(*notes_attrs)
1606                               + notes * sizeof(notes_attrs->attrs[0]),
1607                               GFP_KERNEL);
1608         if (notes_attrs == NULL)
1609                 return;
1610 
1611         notes_attrs->notes = notes;
1612         nattr = &notes_attrs->attrs[0];
1613         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1614                 if (sect_empty(&info->sechdrs[i]))
1615                         continue;
1616                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1617                         sysfs_bin_attr_init(nattr);
1618                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1619                         nattr->attr.mode = S_IRUGO;
1620                         nattr->size = info->sechdrs[i].sh_size;
1621                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1622                         nattr->read = module_notes_read;
1623                         ++nattr;
1624                 }
1625                 ++loaded;
1626         }
1627 
1628         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1629         if (!notes_attrs->dir)
1630                 goto out;
1631 
1632         for (i = 0; i < notes; ++i)
1633                 if (sysfs_create_bin_file(notes_attrs->dir,
1634                                           &notes_attrs->attrs[i]))
1635                         goto out;
1636 
1637         mod->notes_attrs = notes_attrs;
1638         return;
1639 
1640   out:
1641         free_notes_attrs(notes_attrs, i);
1642 }
1643 
1644 static void remove_notes_attrs(struct module *mod)
1645 {
1646         if (mod->notes_attrs)
1647                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1648 }
1649 
1650 #else
1651 
1652 static inline void add_sect_attrs(struct module *mod,
1653                                   const struct load_info *info)
1654 {
1655 }
1656 
1657 static inline void remove_sect_attrs(struct module *mod)
1658 {
1659 }
1660 
1661 static inline void add_notes_attrs(struct module *mod,
1662                                    const struct load_info *info)
1663 {
1664 }
1665 
1666 static inline void remove_notes_attrs(struct module *mod)
1667 {
1668 }
1669 #endif /* CONFIG_KALLSYMS */
1670 
1671 static void add_usage_links(struct module *mod)
1672 {
1673 #ifdef CONFIG_MODULE_UNLOAD
1674         struct module_use *use;
1675         int nowarn;
1676 
1677         mutex_lock(&module_mutex);
1678         list_for_each_entry(use, &mod->target_list, target_list) {
1679                 nowarn = sysfs_create_link(use->target->holders_dir,
1680                                            &mod->mkobj.kobj, mod->name);
1681         }
1682         mutex_unlock(&module_mutex);
1683 #endif
1684 }
1685 
1686 static void del_usage_links(struct module *mod)
1687 {
1688 #ifdef CONFIG_MODULE_UNLOAD
1689         struct module_use *use;
1690 
1691         mutex_lock(&module_mutex);
1692         list_for_each_entry(use, &mod->target_list, target_list)
1693                 sysfs_remove_link(use->target->holders_dir, mod->name);
1694         mutex_unlock(&module_mutex);
1695 #endif
1696 }
1697 
1698 static int module_add_modinfo_attrs(struct module *mod)
1699 {
1700         struct module_attribute *attr;
1701         struct module_attribute *temp_attr;
1702         int error = 0;
1703         int i;
1704 
1705         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1706                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1707                                         GFP_KERNEL);
1708         if (!mod->modinfo_attrs)
1709                 return -ENOMEM;
1710 
1711         temp_attr = mod->modinfo_attrs;
1712         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1713                 if (!attr->test ||
1714                     (attr->test && attr->test(mod))) {
1715                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1716                         sysfs_attr_init(&temp_attr->attr);
1717                         error = sysfs_create_file(&mod->mkobj.kobj,
1718                                         &temp_attr->attr);
1719                         ++temp_attr;
1720                 }
1721         }
1722         return error;
1723 }
1724 
1725 static void module_remove_modinfo_attrs(struct module *mod)
1726 {
1727         struct module_attribute *attr;
1728         int i;
1729 
1730         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1731                 /* pick a field to test for end of list */
1732                 if (!attr->attr.name)
1733                         break;
1734                 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1735                 if (attr->free)
1736                         attr->free(mod);
1737         }
1738         kfree(mod->modinfo_attrs);
1739 }
1740 
1741 static void mod_kobject_put(struct module *mod)
1742 {
1743         DECLARE_COMPLETION_ONSTACK(c);
1744         mod->mkobj.kobj_completion = &c;
1745         kobject_put(&mod->mkobj.kobj);
1746         wait_for_completion(&c);
1747 }
1748 
1749 static int mod_sysfs_init(struct module *mod)
1750 {
1751         int err;
1752         struct kobject *kobj;
1753 
1754         if (!module_sysfs_initialized) {
1755                 pr_err("%s: module sysfs not initialized\n", mod->name);
1756                 err = -EINVAL;
1757                 goto out;
1758         }
1759 
1760         kobj = kset_find_obj(module_kset, mod->name);
1761         if (kobj) {
1762                 pr_err("%s: module is already loaded\n", mod->name);
1763                 kobject_put(kobj);
1764                 err = -EINVAL;
1765                 goto out;
1766         }
1767 
1768         mod->mkobj.mod = mod;
1769 
1770         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1771         mod->mkobj.kobj.kset = module_kset;
1772         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1773                                    "%s", mod->name);
1774         if (err)
1775                 mod_kobject_put(mod);
1776 
1777         /* delay uevent until full sysfs population */
1778 out:
1779         return err;
1780 }
1781 
1782 static int mod_sysfs_setup(struct module *mod,
1783                            const struct load_info *info,
1784                            struct kernel_param *kparam,
1785                            unsigned int num_params)
1786 {
1787         int err;
1788 
1789         err = mod_sysfs_init(mod);
1790         if (err)
1791                 goto out;
1792 
1793         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1794         if (!mod->holders_dir) {
1795                 err = -ENOMEM;
1796                 goto out_unreg;
1797         }
1798 
1799         err = module_param_sysfs_setup(mod, kparam, num_params);
1800         if (err)
1801                 goto out_unreg_holders;
1802 
1803         err = module_add_modinfo_attrs(mod);
1804         if (err)
1805                 goto out_unreg_param;
1806 
1807         add_usage_links(mod);
1808         add_sect_attrs(mod, info);
1809         add_notes_attrs(mod, info);
1810 
1811         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1812         return 0;
1813 
1814 out_unreg_param:
1815         module_param_sysfs_remove(mod);
1816 out_unreg_holders:
1817         kobject_put(mod->holders_dir);
1818 out_unreg:
1819         mod_kobject_put(mod);
1820 out:
1821         return err;
1822 }
1823 
1824 static void mod_sysfs_fini(struct module *mod)
1825 {
1826         remove_notes_attrs(mod);
1827         remove_sect_attrs(mod);
1828         mod_kobject_put(mod);
1829 }
1830 
1831 static void init_param_lock(struct module *mod)
1832 {
1833         mutex_init(&mod->param_lock);
1834 }
1835 #else /* !CONFIG_SYSFS */
1836 
1837 static int mod_sysfs_setup(struct module *mod,
1838                            const struct load_info *info,
1839                            struct kernel_param *kparam,
1840                            unsigned int num_params)
1841 {
1842         return 0;
1843 }
1844 
1845 static void mod_sysfs_fini(struct module *mod)
1846 {
1847 }
1848 
1849 static void module_remove_modinfo_attrs(struct module *mod)
1850 {
1851 }
1852 
1853 static void del_usage_links(struct module *mod)
1854 {
1855 }
1856 
1857 static void init_param_lock(struct module *mod)
1858 {
1859 }
1860 #endif /* CONFIG_SYSFS */
1861 
1862 static void mod_sysfs_teardown(struct module *mod)
1863 {
1864         del_usage_links(mod);
1865         module_remove_modinfo_attrs(mod);
1866         module_param_sysfs_remove(mod);
1867         kobject_put(mod->mkobj.drivers_dir);
1868         kobject_put(mod->holders_dir);
1869         mod_sysfs_fini(mod);
1870 }
1871 
1872 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1873 /*
1874  * LKM RO/NX protection: protect module's text/ro-data
1875  * from modification and any data from execution.
1876  */
1877 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1878 {
1879         unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1880         unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1881 
1882         if (end_pfn > begin_pfn)
1883                 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1884 }
1885 
1886 static void set_section_ro_nx(void *base,
1887                         unsigned long text_size,
1888                         unsigned long ro_size,
1889                         unsigned long total_size)
1890 {
1891         /* begin and end PFNs of the current subsection */
1892         unsigned long begin_pfn;
1893         unsigned long end_pfn;
1894 
1895         /*
1896          * Set RO for module text and RO-data:
1897          * - Always protect first page.
1898          * - Do not protect last partial page.
1899          */
1900         if (ro_size > 0)
1901                 set_page_attributes(base, base + ro_size, set_memory_ro);
1902 
1903         /*
1904          * Set NX permissions for module data:
1905          * - Do not protect first partial page.
1906          * - Always protect last page.
1907          */
1908         if (total_size > text_size) {
1909                 begin_pfn = PFN_UP((unsigned long)base + text_size);
1910                 end_pfn = PFN_UP((unsigned long)base + total_size);
1911                 if (end_pfn > begin_pfn)
1912                         set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1913         }
1914 }
1915 
1916 static void unset_module_core_ro_nx(struct module *mod)
1917 {
1918         set_page_attributes(mod->module_core + mod->core_text_size,
1919                 mod->module_core + mod->core_size,
1920                 set_memory_x);
1921         set_page_attributes(mod->module_core,
1922                 mod->module_core + mod->core_ro_size,
1923                 set_memory_rw);
1924 }
1925 
1926 static void unset_module_init_ro_nx(struct module *mod)
1927 {
1928         set_page_attributes(mod->module_init + mod->init_text_size,
1929                 mod->module_init + mod->init_size,
1930                 set_memory_x);
1931         set_page_attributes(mod->module_init,
1932                 mod->module_init + mod->init_ro_size,
1933                 set_memory_rw);
1934 }
1935 
1936 /* Iterate through all modules and set each module's text as RW */
1937 void set_all_modules_text_rw(void)
1938 {
1939         struct module *mod;
1940 
1941         mutex_lock(&module_mutex);
1942         list_for_each_entry_rcu(mod, &modules, list) {
1943                 if (mod->state == MODULE_STATE_UNFORMED)
1944                         continue;
1945                 if ((mod->module_core) && (mod->core_text_size)) {
1946                         set_page_attributes(mod->module_core,
1947                                                 mod->module_core + mod->core_text_size,
1948                                                 set_memory_rw);
1949                 }
1950                 if ((mod->module_init) && (mod->init_text_size)) {
1951                         set_page_attributes(mod->module_init,
1952                                                 mod->module_init + mod->init_text_size,
1953                                                 set_memory_rw);
1954                 }
1955         }
1956         mutex_unlock(&module_mutex);
1957 }
1958 
1959 /* Iterate through all modules and set each module's text as RO */
1960 void set_all_modules_text_ro(void)
1961 {
1962         struct module *mod;
1963 
1964         mutex_lock(&module_mutex);
1965         list_for_each_entry_rcu(mod, &modules, list) {
1966                 if (mod->state == MODULE_STATE_UNFORMED)
1967                         continue;
1968                 if ((mod->module_core) && (mod->core_text_size)) {
1969                         set_page_attributes(mod->module_core,
1970                                                 mod->module_core + mod->core_text_size,
1971                                                 set_memory_ro);
1972                 }
1973                 if ((mod->module_init) && (mod->init_text_size)) {
1974                         set_page_attributes(mod->module_init,
1975                                                 mod->module_init + mod->init_text_size,
1976                                                 set_memory_ro);
1977                 }
1978         }
1979         mutex_unlock(&module_mutex);
1980 }
1981 #else
1982 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1983 static void unset_module_core_ro_nx(struct module *mod) { }
1984 static void unset_module_init_ro_nx(struct module *mod) { }
1985 #endif
1986 
1987 void __weak module_memfree(void *module_region)
1988 {
1989         vfree(module_region);
1990 }
1991 
1992 void __weak module_arch_cleanup(struct module *mod)
1993 {
1994 }
1995 
1996 void __weak module_arch_freeing_init(struct module *mod)
1997 {
1998 }
1999 
2000 /* Free a module, remove from lists, etc. */
2001 static void free_module(struct module *mod)
2002 {
2003         trace_module_free(mod);
2004 
2005         mod_sysfs_teardown(mod);
2006 
2007         /* We leave it in list to prevent duplicate loads, but make sure
2008          * that noone uses it while it's being deconstructed. */
2009         mutex_lock(&module_mutex);
2010         mod->state = MODULE_STATE_UNFORMED;
2011         mutex_unlock(&module_mutex);
2012 
2013         /* Remove dynamic debug info */
2014         ddebug_remove_module(mod->name);
2015 
2016         /* Arch-specific cleanup. */
2017         module_arch_cleanup(mod);
2018 
2019         /* Module unload stuff */
2020         module_unload_free(mod);
2021 
2022         /* Free any allocated parameters. */
2023         destroy_params(mod->kp, mod->num_kp);
2024 
2025         /* Now we can delete it from the lists */
2026         mutex_lock(&module_mutex);
2027         /* Unlink carefully: kallsyms could be walking list. */
2028         list_del_rcu(&mod->list);
2029         mod_tree_remove(mod);
2030         /* Remove this module from bug list, this uses list_del_rcu */
2031         module_bug_cleanup(mod);
2032         /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2033         synchronize_sched();
2034         mutex_unlock(&module_mutex);
2035 
2036         /* This may be NULL, but that's OK */
2037         unset_module_init_ro_nx(mod);
2038         module_arch_freeing_init(mod);
2039         module_memfree(mod->module_init);
2040         kfree(mod->args);
2041         percpu_modfree(mod);
2042 
2043         /* Free lock-classes; relies on the preceding sync_rcu(). */
2044         lockdep_free_key_range(mod->module_core, mod->core_size);
2045 
2046         /* Finally, free the core (containing the module structure) */
2047         unset_module_core_ro_nx(mod);
2048         module_memfree(mod->module_core);
2049 
2050 #ifdef CONFIG_MPU
2051         update_protections(current->mm);
2052 #endif
2053 }
2054 
2055 void *__symbol_get(const char *symbol)
2056 {
2057         struct module *owner;
2058         const struct kernel_symbol *sym;
2059 
2060         preempt_disable();
2061         sym = find_symbol(symbol, &owner, NULL, true, true);
2062         if (sym && strong_try_module_get(owner))
2063                 sym = NULL;
2064         preempt_enable();
2065 
2066         return sym ? (void *)sym->value : NULL;
2067 }
2068 EXPORT_SYMBOL_GPL(__symbol_get);
2069 
2070 /*
2071  * Ensure that an exported symbol [global namespace] does not already exist
2072  * in the kernel or in some other module's exported symbol table.
2073  *
2074  * You must hold the module_mutex.
2075  */
2076 static int verify_export_symbols(struct module *mod)
2077 {
2078         unsigned int i;
2079         struct module *owner;
2080         const struct kernel_symbol *s;
2081         struct {
2082                 const struct kernel_symbol *sym;
2083                 unsigned int num;
2084         } arr[] = {
2085                 { mod->syms, mod->num_syms },
2086                 { mod->gpl_syms, mod->num_gpl_syms },
2087                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2088 #ifdef CONFIG_UNUSED_SYMBOLS
2089                 { mod->unused_syms, mod->num_unused_syms },
2090                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2091 #endif
2092         };
2093 
2094         for (i = 0; i < ARRAY_SIZE(arr); i++) {
2095                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2096                         if (find_symbol(s->name, &owner, NULL, true, false)) {
2097                                 pr_err("%s: exports duplicate symbol %s"
2098                                        " (owned by %s)\n",
2099                                        mod->name, s->name, module_name(owner));
2100                                 return -ENOEXEC;
2101                         }
2102                 }
2103         }
2104         return 0;
2105 }
2106 
2107 /* Change all symbols so that st_value encodes the pointer directly. */
2108 static int simplify_symbols(struct module *mod, const struct load_info *info)
2109 {
2110         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2111         Elf_Sym *sym = (void *)symsec->sh_addr;
2112         unsigned long secbase;
2113         unsigned int i;
2114         int ret = 0;
2115         const struct kernel_symbol *ksym;
2116 
2117         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2118                 const char *name = info->strtab + sym[i].st_name;
2119 
2120                 switch (sym[i].st_shndx) {
2121                 case SHN_COMMON:
2122                         /* Ignore common symbols */
2123                         if (!strncmp(name, "__gnu_lto", 9))
2124                                 break;
2125 
2126                         /* We compiled with -fno-common.  These are not
2127                            supposed to happen.  */
2128                         pr_debug("Common symbol: %s\n", name);
2129                         pr_warn("%s: please compile with -fno-common\n",
2130                                mod->name);
2131                         ret = -ENOEXEC;
2132                         break;
2133 
2134                 case SHN_ABS:
2135                         /* Don't need to do anything */
2136                         pr_debug("Absolute symbol: 0x%08lx\n",
2137                                (long)sym[i].st_value);
2138                         break;
2139 
2140                 case SHN_UNDEF:
2141                         ksym = resolve_symbol_wait(mod, info, name);
2142                         /* Ok if resolved.  */
2143                         if (ksym && !IS_ERR(ksym)) {
2144                                 sym[i].st_value = ksym->value;
2145                                 break;
2146                         }
2147 
2148                         /* Ok if weak.  */
2149                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2150                                 break;
2151 
2152                         pr_warn("%s: Unknown symbol %s (err %li)\n",
2153                                 mod->name, name, PTR_ERR(ksym));
2154                         ret = PTR_ERR(ksym) ?: -ENOENT;
2155                         break;
2156 
2157                 default:
2158                         /* Divert to percpu allocation if a percpu var. */
2159                         if (sym[i].st_shndx == info->index.pcpu)
2160                                 secbase = (unsigned long)mod_percpu(mod);
2161                         else
2162                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2163                         sym[i].st_value += secbase;
2164                         break;
2165                 }
2166         }
2167 
2168         return ret;
2169 }
2170 
2171 static int apply_relocations(struct module *mod, const struct load_info *info)
2172 {
2173         unsigned int i;
2174         int err = 0;
2175 
2176         /* Now do relocations. */
2177         for (i = 1; i < info->hdr->e_shnum; i++) {
2178                 unsigned int infosec = info->sechdrs[i].sh_info;
2179 
2180                 /* Not a valid relocation section? */
2181                 if (infosec >= info->hdr->e_shnum)
2182                         continue;
2183 
2184                 /* Don't bother with non-allocated sections */
2185                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2186                         continue;
2187 
2188                 if (info->sechdrs[i].sh_type == SHT_REL)
2189                         err = apply_relocate(info->sechdrs, info->strtab,
2190                                              info->index.sym, i, mod);
2191                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2192                         err = apply_relocate_add(info->sechdrs, info->strtab,
2193                                                  info->index.sym, i, mod);
2194                 if (err < 0)
2195                         break;
2196         }
2197         return err;
2198 }
2199 
2200 /* Additional bytes needed by arch in front of individual sections */
2201 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2202                                              unsigned int section)
2203 {
2204         /* default implementation just returns zero */
2205         return 0;
2206 }
2207 
2208 /* Update size with this section: return offset. */
2209 static long get_offset(struct module *mod, unsigned int *size,
2210                        Elf_Shdr *sechdr, unsigned int section)
2211 {
2212         long ret;
2213 
2214         *size += arch_mod_section_prepend(mod, section);
2215         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2216         *size = ret + sechdr->sh_size;
2217         return ret;
2218 }
2219 
2220 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2221    might -- code, read-only data, read-write data, small data.  Tally
2222    sizes, and place the offsets into sh_entsize fields: high bit means it
2223    belongs in init. */
2224 static void layout_sections(struct module *mod, struct load_info *info)
2225 {
2226         static unsigned long const masks[][2] = {
2227                 /* NOTE: all executable code must be the first section
2228                  * in this array; otherwise modify the text_size
2229                  * finder in the two loops below */
2230                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2231                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2232                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2233                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2234         };
2235         unsigned int m, i;
2236 
2237         for (i = 0; i < info->hdr->e_shnum; i++)
2238                 info->sechdrs[i].sh_entsize = ~0UL;
2239 
2240         pr_debug("Core section allocation order:\n");
2241         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2242                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2243                         Elf_Shdr *s = &info->sechdrs[i];
2244                         const char *sname = info->secstrings + s->sh_name;
2245 
2246                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2247                             || (s->sh_flags & masks[m][1])
2248                             || s->sh_entsize != ~0UL
2249                             || strstarts(sname, ".init"))
2250                                 continue;
2251                         s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2252                         pr_debug("\t%s\n", sname);
2253                 }
2254                 switch (m) {
2255                 case 0: /* executable */
2256                         mod->core_size = debug_align(mod->core_size);
2257                         mod->core_text_size = mod->core_size;
2258                         break;
2259                 case 1: /* RO: text and ro-data */
2260                         mod->core_size = debug_align(mod->core_size);
2261                         mod->core_ro_size = mod->core_size;
2262                         break;
2263                 case 3: /* whole core */
2264                         mod->core_size = debug_align(mod->core_size);
2265                         break;
2266                 }
2267         }
2268 
2269         pr_debug("Init section allocation order:\n");
2270         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2271                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2272                         Elf_Shdr *s = &info->sechdrs[i];
2273                         const char *sname = info->secstrings + s->sh_name;
2274 
2275                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2276                             || (s->sh_flags & masks[m][1])
2277                             || s->sh_entsize != ~0UL
2278                             || !strstarts(sname, ".init"))
2279                                 continue;
2280                         s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2281                                          | INIT_OFFSET_MASK);
2282                         pr_debug("\t%s\n", sname);
2283                 }
2284                 switch (m) {
2285                 case 0: /* executable */
2286                         mod->init_size = debug_align(mod->init_size);
2287                         mod->init_text_size = mod->init_size;
2288                         break;
2289                 case 1: /* RO: text and ro-data */
2290                         mod->init_size = debug_align(mod->init_size);
2291                         mod->init_ro_size = mod->init_size;
2292                         break;
2293                 case 3: /* whole init */
2294                         mod->init_size = debug_align(mod->init_size);
2295                         break;
2296                 }
2297         }
2298 }
2299 
2300 static void set_license(struct module *mod, const char *license)
2301 {
2302         if (!license)
2303                 license = "unspecified";
2304 
2305         if (!license_is_gpl_compatible(license)) {
2306                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2307                         pr_warn("%s: module license '%s' taints kernel.\n",
2308                                 mod->name, license);
2309                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2310                                  LOCKDEP_NOW_UNRELIABLE);
2311         }
2312 }
2313 
2314 /* Parse tag=value strings from .modinfo section */
2315 static char *next_string(char *string, unsigned long *secsize)
2316 {
2317         /* Skip non-zero chars */
2318         while (string[0]) {
2319                 string++;
2320                 if ((*secsize)-- <= 1)
2321                         return NULL;
2322         }
2323 
2324         /* Skip any zero padding. */
2325         while (!string[0]) {
2326                 string++;
2327                 if ((*secsize)-- <= 1)
2328                         return NULL;
2329         }
2330         return string;
2331 }
2332 
2333 static char *get_modinfo(struct load_info *info, const char *tag)
2334 {
2335         char *p;
2336         unsigned int taglen = strlen(tag);
2337         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2338         unsigned long size = infosec->sh_size;
2339 
2340         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2341                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2342                         return p + taglen + 1;
2343         }
2344         return NULL;
2345 }
2346 
2347 static void setup_modinfo(struct module *mod, struct load_info *info)
2348 {
2349         struct module_attribute *attr;
2350         int i;
2351 
2352         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2353                 if (attr->setup)
2354                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2355         }
2356 }
2357 
2358 static void free_modinfo(struct module *mod)
2359 {
2360         struct module_attribute *attr;
2361         int i;
2362 
2363         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2364                 if (attr->free)
2365                         attr->free(mod);
2366         }
2367 }
2368 
2369 #ifdef CONFIG_KALLSYMS
2370 
2371 /* lookup symbol in given range of kernel_symbols */
2372 static const struct kernel_symbol *lookup_symbol(const char *name,
2373         const struct kernel_symbol *start,
2374         const struct kernel_symbol *stop)
2375 {
2376         return bsearch(name, start, stop - start,
2377                         sizeof(struct kernel_symbol), cmp_name);
2378 }
2379 
2380 static int is_exported(const char *name, unsigned long value,
2381                        const struct module *mod)
2382 {
2383         const struct kernel_symbol *ks;
2384         if (!mod)
2385                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2386         else
2387                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2388         return ks != NULL && ks->value == value;
2389 }
2390 
2391 /* As per nm */
2392 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2393 {
2394         const Elf_Shdr *sechdrs = info->sechdrs;
2395 
2396         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2397                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2398                         return 'v';
2399                 else
2400                         return 'w';
2401         }
2402         if (sym->st_shndx == SHN_UNDEF)
2403                 return 'U';
2404         if (sym->st_shndx == SHN_ABS)
2405                 return 'a';
2406         if (sym->st_shndx >= SHN_LORESERVE)
2407                 return '?';
2408         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2409                 return 't';
2410         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2411             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2412                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2413                         return 'r';
2414                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2415                         return 'g';
2416                 else
2417                         return 'd';
2418         }
2419         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2420                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2421                         return 's';
2422                 else
2423                         return 'b';
2424         }
2425         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2426                       ".debug")) {
2427                 return 'n';
2428         }
2429         return '?';
2430 }
2431 
2432 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2433                         unsigned int shnum)
2434 {
2435         const Elf_Shdr *sec;
2436 
2437         if (src->st_shndx == SHN_UNDEF
2438             || src->st_shndx >= shnum
2439             || !src->st_name)
2440                 return false;
2441 
2442         sec = sechdrs + src->st_shndx;
2443         if (!(sec->sh_flags & SHF_ALLOC)
2444 #ifndef CONFIG_KALLSYMS_ALL
2445             || !(sec->sh_flags & SHF_EXECINSTR)
2446 #endif
2447             || (sec->sh_entsize & INIT_OFFSET_MASK))
2448                 return false;
2449 
2450         return true;
2451 }
2452 
2453 /*
2454  * We only allocate and copy the strings needed by the parts of symtab
2455  * we keep.  This is simple, but has the effect of making multiple
2456  * copies of duplicates.  We could be more sophisticated, see
2457  * linux-kernel thread starting with
2458  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2459  */
2460 static void layout_symtab(struct module *mod, struct load_info *info)
2461 {
2462         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2463         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2464         const Elf_Sym *src;
2465         unsigned int i, nsrc, ndst, strtab_size = 0;
2466 
2467         /* Put symbol section at end of init part of module. */
2468         symsect->sh_flags |= SHF_ALLOC;
2469         symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2470                                          info->index.sym) | INIT_OFFSET_MASK;
2471         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2472 
2473         src = (void *)info->hdr + symsect->sh_offset;
2474         nsrc = symsect->sh_size / sizeof(*src);
2475 
2476         /* Compute total space required for the core symbols' strtab. */
2477         for (ndst = i = 0; i < nsrc; i++) {
2478                 if (i == 0 ||
2479                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2480                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2481                         ndst++;
2482                 }
2483         }
2484 
2485         /* Append room for core symbols at end of core part. */
2486         info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2487         info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2488         mod->core_size += strtab_size;
2489         mod->core_size = debug_align(mod->core_size);
2490 
2491         /* Put string table section at end of init part of module. */
2492         strsect->sh_flags |= SHF_ALLOC;
2493         strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2494                                          info->index.str) | INIT_OFFSET_MASK;
2495         mod->init_size = debug_align(mod->init_size);
2496         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2497 }
2498 
2499 static void add_kallsyms(struct module *mod, const struct load_info *info)
2500 {
2501         unsigned int i, ndst;
2502         const Elf_Sym *src;
2503         Elf_Sym *dst;
2504         char *s;
2505         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2506 
2507         mod->symtab = (void *)symsec->sh_addr;
2508         mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2509         /* Make sure we get permanent strtab: don't use info->strtab. */
2510         mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2511 
2512         /* Set types up while we still have access to sections. */
2513         for (i = 0; i < mod->num_symtab; i++)
2514                 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2515 
2516         mod->core_symtab = dst = mod->module_core + info->symoffs;
2517         mod->core_strtab = s = mod->module_core + info->stroffs;
2518         src = mod->symtab;
2519         for (ndst = i = 0; i < mod->num_symtab; i++) {
2520                 if (i == 0 ||
2521                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2522                         dst[ndst] = src[i];
2523                         dst[ndst++].st_name = s - mod->core_strtab;
2524                         s += strlcpy(s, &mod->strtab[src[i].st_name],
2525                                      KSYM_NAME_LEN) + 1;
2526                 }
2527         }
2528         mod->core_num_syms = ndst;
2529 }
2530 #else
2531 static inline void layout_symtab(struct module *mod, struct load_info *info)
2532 {
2533 }
2534 
2535 static void add_kallsyms(struct module *mod, const struct load_info *info)
2536 {
2537 }
2538 #endif /* CONFIG_KALLSYMS */
2539 
2540 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2541 {
2542         if (!debug)
2543                 return;
2544 #ifdef CONFIG_DYNAMIC_DEBUG
2545         if (ddebug_add_module(debug, num, debug->modname))
2546                 pr_err("dynamic debug error adding module: %s\n",
2547                         debug->modname);
2548 #endif
2549 }
2550 
2551 static void dynamic_debug_remove(struct _ddebug *debug)
2552 {
2553         if (debug)
2554                 ddebug_remove_module(debug->modname);
2555 }
2556 
2557 void * __weak module_alloc(unsigned long size)
2558 {
2559         return vmalloc_exec(size);
2560 }
2561 
2562 #ifdef CONFIG_DEBUG_KMEMLEAK
2563 static void kmemleak_load_module(const struct module *mod,
2564                                  const struct load_info *info)
2565 {
2566         unsigned int i;
2567 
2568         /* only scan the sections containing data */
2569         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2570 
2571         for (i = 1; i < info->hdr->e_shnum; i++) {
2572                 /* Scan all writable sections that's not executable */
2573                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2574                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2575                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2576                         continue;
2577 
2578                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2579                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2580         }
2581 }
2582 #else
2583 static inline void kmemleak_load_module(const struct module *mod,
2584                                         const struct load_info *info)
2585 {
2586 }
2587 #endif
2588 
2589 #ifdef CONFIG_MODULE_SIG
2590 static int module_sig_check(struct load_info *info)
2591 {
2592         int err = -ENOKEY;
2593         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2594         const void *mod = info->hdr;
2595 
2596         if (info->len > markerlen &&
2597             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2598                 /* We truncate the module to discard the signature */
2599                 info->len -= markerlen;
2600                 err = mod_verify_sig(mod, &info->len);
2601         }
2602 
2603         if (!err) {
2604                 info->sig_ok = true;
2605                 return 0;
2606         }
2607 
2608         /* Not having a signature is only an error if we're strict. */
2609         if (err == -ENOKEY && !sig_enforce)
2610                 err = 0;
2611 
2612         return err;
2613 }
2614 #else /* !CONFIG_MODULE_SIG */
2615 static int module_sig_check(struct load_info *info)
2616 {
2617         return 0;
2618 }
2619 #endif /* !CONFIG_MODULE_SIG */
2620 
2621 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2622 static int elf_header_check(struct load_info *info)
2623 {
2624         if (info->len < sizeof(*(info->hdr)))
2625                 return -ENOEXEC;
2626 
2627         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2628             || info->hdr->e_type != ET_REL
2629             || !elf_check_arch(info->hdr)
2630             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2631                 return -ENOEXEC;
2632 
2633         if (info->hdr->e_shoff >= info->len
2634             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2635                 info->len - info->hdr->e_shoff))
2636                 return -ENOEXEC;
2637 
2638         return 0;
2639 }
2640 
2641 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2642 
2643 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2644 {
2645         do {
2646                 unsigned long n = min(len, COPY_CHUNK_SIZE);
2647 
2648                 if (copy_from_user(dst, usrc, n) != 0)
2649                         return -EFAULT;
2650                 cond_resched();
2651                 dst += n;
2652                 usrc += n;
2653                 len -= n;
2654         } while (len);
2655         return 0;
2656 }
2657 
2658 /* Sets info->hdr and info->len. */
2659 static int copy_module_from_user(const void __user *umod, unsigned long len,
2660                                   struct load_info *info)
2661 {
2662         int err;
2663 
2664         info->len = len;
2665         if (info->len < sizeof(*(info->hdr)))
2666                 return -ENOEXEC;
2667 
2668         err = security_kernel_module_from_file(NULL);
2669         if (err)
2670                 return err;
2671 
2672         /* Suck in entire file: we'll want most of it. */
2673         info->hdr = __vmalloc(info->len,
2674                         GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2675         if (!info->hdr)
2676                 return -ENOMEM;
2677 
2678         if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2679                 vfree(info->hdr);
2680                 return -EFAULT;
2681         }
2682 
2683         return 0;
2684 }
2685 
2686 /* Sets info->hdr and info->len. */
2687 static int copy_module_from_fd(int fd, struct load_info *info)
2688 {
2689         struct fd f = fdget(fd);
2690         int err;
2691         struct kstat stat;
2692         loff_t pos;
2693         ssize_t bytes = 0;
2694 
2695         if (!f.file)
2696                 return -ENOEXEC;
2697 
2698         err = security_kernel_module_from_file(f.file);
2699         if (err)
2700                 goto out;
2701 
2702         err = vfs_getattr(&f.file->f_path, &stat);
2703         if (err)
2704                 goto out;
2705 
2706         if (stat.size > INT_MAX) {
2707                 err = -EFBIG;
2708                 goto out;
2709         }
2710 
2711         /* Don't hand 0 to vmalloc, it whines. */
2712         if (stat.size == 0) {
2713                 err = -EINVAL;
2714                 goto out;
2715         }
2716 
2717         info->hdr = vmalloc(stat.size);
2718         if (!info->hdr) {
2719                 err = -ENOMEM;
2720                 goto out;
2721         }
2722 
2723         pos = 0;
2724         while (pos < stat.size) {
2725                 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2726                                     stat.size - pos);
2727                 if (bytes < 0) {
2728                         vfree(info->hdr);
2729                         err = bytes;
2730                         goto out;
2731                 }
2732                 if (bytes == 0)
2733                         break;
2734                 pos += bytes;
2735         }
2736         info->len = pos;
2737 
2738 out:
2739         fdput(f);
2740         return err;
2741 }
2742 
2743 static void free_copy(struct load_info *info)
2744 {
2745         vfree(info->hdr);
2746 }
2747 
2748 static int rewrite_section_headers(struct load_info *info, int flags)
2749 {
2750         unsigned int i;
2751 
2752         /* This should always be true, but let's be sure. */
2753         info->sechdrs[0].sh_addr = 0;
2754 
2755         for (i = 1; i < info->hdr->e_shnum; i++) {
2756                 Elf_Shdr *shdr = &info->sechdrs[i];
2757                 if (shdr->sh_type != SHT_NOBITS
2758                     && info->len < shdr->sh_offset + shdr->sh_size) {
2759                         pr_err("Module len %lu truncated\n", info->len);
2760                         return -ENOEXEC;
2761                 }
2762 
2763                 /* Mark all sections sh_addr with their address in the
2764                    temporary image. */
2765                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2766 
2767 #ifndef CONFIG_MODULE_UNLOAD
2768                 /* Don't load .exit sections */
2769                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2770                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2771 #endif
2772         }
2773 
2774         /* Track but don't keep modinfo and version sections. */
2775         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2776                 info->index.vers = 0; /* Pretend no __versions section! */
2777         else
2778                 info->index.vers = find_sec(info, "__versions");
2779         info->index.info = find_sec(info, ".modinfo");
2780         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2781         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2782         return 0;
2783 }
2784 
2785 /*
2786  * Set up our basic convenience variables (pointers to section headers,
2787  * search for module section index etc), and do some basic section
2788  * verification.
2789  *
2790  * Return the temporary module pointer (we'll replace it with the final
2791  * one when we move the module sections around).
2792  */
2793 static struct module *setup_load_info(struct load_info *info, int flags)
2794 {
2795         unsigned int i;
2796         int err;
2797         struct module *mod;
2798 
2799         /* Set up the convenience variables */
2800         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2801         info->secstrings = (void *)info->hdr
2802                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2803 
2804         err = rewrite_section_headers(info, flags);
2805         if (err)
2806                 return ERR_PTR(err);
2807 
2808         /* Find internal symbols and strings. */
2809         for (i = 1; i < info->hdr->e_shnum; i++) {
2810                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2811                         info->index.sym = i;
2812                         info->index.str = info->sechdrs[i].sh_link;
2813                         info->strtab = (char *)info->hdr
2814                                 + info->sechdrs[info->index.str].sh_offset;
2815                         break;
2816                 }
2817         }
2818 
2819         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2820         if (!info->index.mod) {
2821                 pr_warn("No module found in object\n");
2822                 return ERR_PTR(-ENOEXEC);
2823         }
2824         /* This is temporary: point mod into copy of data. */
2825         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2826 
2827         if (info->index.sym == 0) {
2828                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2829                 return ERR_PTR(-ENOEXEC);
2830         }
2831 
2832         info->index.pcpu = find_pcpusec(info);
2833 
2834         /* Check module struct version now, before we try to use module. */
2835         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2836                 return ERR_PTR(-ENOEXEC);
2837 
2838         return mod;
2839 }
2840 
2841 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2842 {
2843         const char *modmagic = get_modinfo(info, "vermagic");
2844         int err;
2845 
2846         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2847                 modmagic = NULL;
2848 
2849         /* This is allowed: modprobe --force will invalidate it. */
2850         if (!modmagic) {
2851                 err = try_to_force_load(mod, "bad vermagic");
2852                 if (err)
2853                         return err;
2854         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2855                 pr_err("%s: version magic '%s' should be '%s'\n",
2856                        mod->name, modmagic, vermagic);
2857                 return -ENOEXEC;
2858         }
2859 
2860         if (!get_modinfo(info, "intree"))
2861                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2862 
2863         if (get_modinfo(info, "staging")) {
2864                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2865                 pr_warn("%s: module is from the staging directory, the quality "
2866                         "is unknown, you have been warned.\n", mod->name);
2867         }
2868 
2869         /* Set up license info based on the info section */
2870         set_license(mod, get_modinfo(info, "license"));
2871 
2872         return 0;
2873 }
2874 
2875 static int find_module_sections(struct module *mod, struct load_info *info)
2876 {
2877         mod->kp = section_objs(info, "__param",
2878                                sizeof(*mod->kp), &mod->num_kp);
2879         mod->syms = section_objs(info, "__ksymtab",
2880                                  sizeof(*mod->syms), &mod->num_syms);
2881         mod->crcs = section_addr(info, "__kcrctab");
2882         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2883                                      sizeof(*mod->gpl_syms),
2884                                      &mod->num_gpl_syms);
2885         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2886         mod->gpl_future_syms = section_objs(info,
2887                                             "__ksymtab_gpl_future",
2888                                             sizeof(*mod->gpl_future_syms),
2889                                             &mod->num_gpl_future_syms);
2890         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2891 
2892 #ifdef CONFIG_UNUSED_SYMBOLS
2893         mod->unused_syms = section_objs(info, "__ksymtab_unused",
2894                                         sizeof(*mod->unused_syms),
2895                                         &mod->num_unused_syms);
2896         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2897         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2898                                             sizeof(*mod->unused_gpl_syms),
2899                                             &mod->num_unused_gpl_syms);
2900         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2901 #endif
2902 #ifdef CONFIG_CONSTRUCTORS
2903         mod->ctors = section_objs(info, ".ctors",
2904                                   sizeof(*mod->ctors), &mod->num_ctors);
2905         if (!mod->ctors)
2906                 mod->ctors = section_objs(info, ".init_array",
2907                                 sizeof(*mod->ctors), &mod->num_ctors);
2908         else if (find_sec(info, ".init_array")) {
2909                 /*
2910                  * This shouldn't happen with same compiler and binutils
2911                  * building all parts of the module.
2912                  */
2913                 pr_warn("%s: has both .ctors and .init_array.\n",
2914                        mod->name);
2915                 return -EINVAL;
2916         }
2917 #endif
2918 
2919 #ifdef CONFIG_TRACEPOINTS
2920         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2921                                              sizeof(*mod->tracepoints_ptrs),
2922                                              &mod->num_tracepoints);
2923 #endif
2924 #ifdef HAVE_JUMP_LABEL
2925         mod->jump_entries = section_objs(info, "__jump_table",
2926                                         sizeof(*mod->jump_entries),
2927                                         &mod->num_jump_entries);
2928 #endif
2929 #ifdef CONFIG_EVENT_TRACING
2930         mod->trace_events = section_objs(info, "_ftrace_events",
2931                                          sizeof(*mod->trace_events),
2932                                          &mod->num_trace_events);
2933         mod->trace_enums = section_objs(info, "_ftrace_enum_map",
2934                                         sizeof(*mod->trace_enums),
2935                                         &mod->num_trace_enums);
2936 #endif
2937 #ifdef CONFIG_TRACING
2938         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2939                                          sizeof(*mod->trace_bprintk_fmt_start),
2940                                          &mod->num_trace_bprintk_fmt);
2941 #endif
2942 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2943         /* sechdrs[0].sh_size is always zero */
2944         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2945                                              sizeof(*mod->ftrace_callsites),
2946                                              &mod->num_ftrace_callsites);
2947 #endif
2948 
2949         mod->extable = section_objs(info, "__ex_table",
2950                                     sizeof(*mod->extable), &mod->num_exentries);
2951 
2952         if (section_addr(info, "__obsparm"))
2953                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2954 
2955         info->debug = section_objs(info, "__verbose",
2956                                    sizeof(*info->debug), &info->num_debug);
2957 
2958         return 0;
2959 }
2960 
2961 static int move_module(struct module *mod, struct load_info *info)
2962 {
2963         int i;
2964         void *ptr;
2965 
2966         /* Do the allocs. */
2967         ptr = module_alloc(mod->core_size);
2968         /*
2969          * The pointer to this block is stored in the module structure
2970          * which is inside the block. Just mark it as not being a
2971          * leak.
2972          */
2973         kmemleak_not_leak(ptr);
2974         if (!ptr)
2975                 return -ENOMEM;
2976 
2977         memset(ptr, 0, mod->core_size);
2978         mod->module_core = ptr;
2979 
2980         if (mod->init_size) {
2981                 ptr = module_alloc(mod->init_size);
2982                 /*
2983                  * The pointer to this block is stored in the module structure
2984                  * which is inside the block. This block doesn't need to be
2985                  * scanned as it contains data and code that will be freed
2986                  * after the module is initialized.
2987                  */
2988                 kmemleak_ignore(ptr);
2989                 if (!ptr) {
2990                         module_memfree(mod->module_core);
2991                         return -ENOMEM;
2992                 }
2993                 memset(ptr, 0, mod->init_size);
2994                 mod->module_init = ptr;
2995         } else
2996                 mod->module_init = NULL;
2997 
2998         /* Transfer each section which specifies SHF_ALLOC */
2999         pr_debug("final section addresses:\n");
3000         for (i = 0; i < info->hdr->e_shnum; i++) {
3001                 void *dest;
3002                 Elf_Shdr *shdr = &info->sechdrs[i];
3003 
3004                 if (!(shdr->sh_flags & SHF_ALLOC))
3005                         continue;
3006 
3007                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3008                         dest = mod->module_init
3009                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3010                 else
3011                         dest = mod->module_core + shdr->sh_entsize;
3012 
3013                 if (shdr->sh_type != SHT_NOBITS)
3014                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3015                 /* Update sh_addr to point to copy in image. */
3016                 shdr->sh_addr = (unsigned long)dest;
3017                 pr_debug("\t0x%lx %s\n",
3018                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3019         }
3020 
3021         return 0;
3022 }
3023 
3024 static int check_module_license_and_versions(struct module *mod)
3025 {
3026         /*
3027          * ndiswrapper is under GPL by itself, but loads proprietary modules.
3028          * Don't use add_taint_module(), as it would prevent ndiswrapper from
3029          * using GPL-only symbols it needs.
3030          */
3031         if (strcmp(mod->name, "ndiswrapper") == 0)
3032                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3033 
3034         /* driverloader was caught wrongly pretending to be under GPL */
3035         if (strcmp(mod->name, "driverloader") == 0)
3036                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3037                                  LOCKDEP_NOW_UNRELIABLE);
3038 
3039         /* lve claims to be GPL but upstream won't provide source */
3040         if (strcmp(mod->name, "lve") == 0)
3041                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3042                                  LOCKDEP_NOW_UNRELIABLE);
3043 
3044 #ifdef CONFIG_MODVERSIONS
3045         if ((mod->num_syms && !mod->crcs)
3046             || (mod->num_gpl_syms && !mod->gpl_crcs)
3047             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3048 #ifdef CONFIG_UNUSED_SYMBOLS
3049             || (mod->num_unused_syms && !mod->unused_crcs)
3050             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3051 #endif
3052                 ) {
3053                 return try_to_force_load(mod,
3054                                          "no versions for exported symbols");
3055         }
3056 #endif
3057         return 0;
3058 }
3059 
3060 static void flush_module_icache(const struct module *mod)
3061 {
3062         mm_segment_t old_fs;
3063 
3064         /* flush the icache in correct context */
3065         old_fs = get_fs();
3066         set_fs(KERNEL_DS);
3067 
3068         /*
3069          * Flush the instruction cache, since we've played with text.
3070          * Do it before processing of module parameters, so the module
3071          * can provide parameter accessor functions of its own.
3072          */
3073         if (mod->module_init)
3074                 flush_icache_range((unsigned long)mod->module_init,
3075                                    (unsigned long)mod->module_init
3076                                    + mod->init_size);
3077         flush_icache_range((unsigned long)mod->module_core,
3078                            (unsigned long)mod->module_core + mod->core_size);
3079 
3080         set_fs(old_fs);
3081 }
3082 
3083 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3084                                      Elf_Shdr *sechdrs,
3085                                      char *secstrings,
3086                                      struct module *mod)
3087 {
3088         return 0;
3089 }
3090 
3091 static struct module *layout_and_allocate(struct load_info *info, int flags)
3092 {
3093         /* Module within temporary copy. */
3094         struct module *mod;
3095         int err;
3096 
3097         mod = setup_load_info(info, flags);
3098         if (IS_ERR(mod))
3099                 return mod;
3100 
3101         err = check_modinfo(mod, info, flags);
3102         if (err)
3103                 return ERR_PTR(err);
3104 
3105         /* Allow arches to frob section contents and sizes.  */
3106         err = module_frob_arch_sections(info->hdr, info->sechdrs,
3107                                         info->secstrings, mod);
3108         if (err < 0)
3109                 return ERR_PTR(err);
3110 
3111         /* We will do a special allocation for per-cpu sections later. */
3112         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3113 
3114         /* Determine total sizes, and put offsets in sh_entsize.  For now
3115            this is done generically; there doesn't appear to be any
3116            special cases for the architectures. */
3117         layout_sections(mod, info);
3118         layout_symtab(mod, info);
3119 
3120         /* Allocate and move to the final place */
3121         err = move_module(mod, info);
3122         if (err)
3123                 return ERR_PTR(err);
3124 
3125         /* Module has been copied to its final place now: return it. */
3126         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3127         kmemleak_load_module(mod, info);
3128         return mod;
3129 }
3130 
3131 /* mod is no longer valid after this! */
3132 static void module_deallocate(struct module *mod, struct load_info *info)
3133 {
3134         percpu_modfree(mod);
3135         module_arch_freeing_init(mod);
3136         module_memfree(mod->module_init);
3137         module_memfree(mod->module_core);
3138 }
3139 
3140 int __weak module_finalize(const Elf_Ehdr *hdr,
3141                            const Elf_Shdr *sechdrs,
3142                            struct module *me)
3143 {
3144         return 0;
3145 }
3146 
3147 static int post_relocation(struct module *mod, const struct load_info *info)
3148 {
3149         /* Sort exception table now relocations are done. */
3150         sort_extable(mod->extable, mod->extable + mod->num_exentries);
3151 
3152         /* Copy relocated percpu area over. */
3153         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3154                        info->sechdrs[info->index.pcpu].sh_size);
3155 
3156         /* Setup kallsyms-specific fields. */
3157         add_kallsyms(mod, info);
3158 
3159         /* Arch-specific module finalizing. */
3160         return module_finalize(info->hdr, info->sechdrs, mod);
3161 }
3162 
3163 /* Is this module of this name done loading?  No locks held. */
3164 static bool finished_loading(const char *name)
3165 {
3166         struct module *mod;
3167         bool ret;
3168 
3169         /*
3170          * The module_mutex should not be a heavily contended lock;
3171          * if we get the occasional sleep here, we'll go an extra iteration
3172          * in the wait_event_interruptible(), which is harmless.
3173          */
3174         sched_annotate_sleep();
3175         mutex_lock(&module_mutex);
3176         mod = find_module_all(name, strlen(name), true);
3177         ret = !mod || mod->state == MODULE_STATE_LIVE
3178                 || mod->state == MODULE_STATE_GOING;
3179         mutex_unlock(&module_mutex);
3180 
3181         return ret;
3182 }
3183 
3184 /* Call module constructors. */
3185 static void do_mod_ctors(struct module *mod)
3186 {
3187 #ifdef CONFIG_CONSTRUCTORS
3188         unsigned long i;
3189 
3190         for (i = 0; i < mod->num_ctors; i++)
3191                 mod->ctors[i]();
3192 #endif
3193 }
3194 
3195 /* For freeing module_init on success, in case kallsyms traversing */
3196 struct mod_initfree {
3197         struct rcu_head rcu;
3198         void *module_init;
3199 };
3200 
3201 static void do_free_init(struct rcu_head *head)
3202 {
3203         struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3204         module_memfree(m->module_init);
3205         kfree(m);
3206 }
3207 
3208 /*
3209  * This is where the real work happens.
3210  *
3211  * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3212  * helper command 'lx-symbols'.
3213  */
3214 static noinline int do_init_module(struct module *mod)
3215 {
3216         int ret = 0;
3217         struct mod_initfree *freeinit;
3218 
3219         freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3220         if (!freeinit) {
3221                 ret = -ENOMEM;
3222                 goto fail;
3223         }
3224         freeinit->module_init = mod->module_init;
3225 
3226         /*
3227          * We want to find out whether @mod uses async during init.  Clear
3228          * PF_USED_ASYNC.  async_schedule*() will set it.
3229          */
3230         current->flags &= ~PF_USED_ASYNC;
3231 
3232         do_mod_ctors(mod);
3233         /* Start the module */
3234         if (mod->init != NULL)
3235                 ret = do_one_initcall(mod->init);
3236         if (ret < 0) {
3237                 goto fail_free_freeinit;
3238         }
3239         if (ret > 0) {
3240                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3241                         "follow 0/-E convention\n"
3242                         "%s: loading module anyway...\n",
3243                         __func__, mod->name, ret, __func__);
3244                 dump_stack();
3245         }
3246 
3247         /* Now it's a first class citizen! */
3248         mod->state = MODULE_STATE_LIVE;
3249         blocking_notifier_call_chain(&module_notify_list,
3250                                      MODULE_STATE_LIVE, mod);
3251 
3252         /*
3253          * We need to finish all async code before the module init sequence
3254          * is done.  This has potential to deadlock.  For example, a newly
3255          * detected block device can trigger request_module() of the
3256          * default iosched from async probing task.  Once userland helper
3257          * reaches here, async_synchronize_full() will wait on the async
3258          * task waiting on request_module() and deadlock.
3259          *
3260          * This deadlock is avoided by perfomring async_synchronize_full()
3261          * iff module init queued any async jobs.  This isn't a full
3262          * solution as it will deadlock the same if module loading from
3263          * async jobs nests more than once; however, due to the various
3264          * constraints, this hack seems to be the best option for now.
3265          * Please refer to the following thread for details.
3266          *
3267          * http://thread.gmane.org/gmane.linux.kernel/1420814
3268          */
3269         if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3270                 async_synchronize_full();
3271 
3272         mutex_lock(&module_mutex);
3273         /* Drop initial reference. */
3274         module_put(mod);
3275         trim_init_extable(mod);
3276 #ifdef CONFIG_KALLSYMS
3277         mod->num_symtab = mod->core_num_syms;
3278         mod->symtab = mod->core_symtab;
3279         mod->strtab = mod->core_strtab;
3280 #endif
3281         mod_tree_remove_init(mod);
3282         unset_module_init_ro_nx(mod);
3283         module_arch_freeing_init(mod);
3284         mod->module_init = NULL;
3285         mod->init_size = 0;
3286         mod->init_ro_size = 0;
3287         mod->init_text_size = 0;
3288         /*
3289          * We want to free module_init, but be aware that kallsyms may be
3290          * walking this with preempt disabled.  In all the failure paths, we
3291          * call synchronize_sched(), but we don't want to slow down the success
3292          * path, so use actual RCU here.
3293          */
3294         call_rcu_sched(&freeinit->rcu, do_free_init);
3295         mutex_unlock(&module_mutex);
3296         wake_up_all(&module_wq);
3297 
3298         return 0;
3299 
3300 fail_free_freeinit:
3301         kfree(freeinit);
3302 fail:
3303         /* Try to protect us from buggy refcounters. */
3304         mod->state = MODULE_STATE_GOING;
3305         synchronize_sched();
3306         module_put(mod);
3307         blocking_notifier_call_chain(&module_notify_list,
3308                                      MODULE_STATE_GOING, mod);
3309         free_module(mod);
3310         wake_up_all(&module_wq);
3311         return ret;
3312 }
3313 
3314 static int may_init_module(void)
3315 {
3316         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3317                 return -EPERM;
3318 
3319         return 0;
3320 }
3321 
3322 /*
3323  * We try to place it in the list now to make sure it's unique before
3324  * we dedicate too many resources.  In particular, temporary percpu
3325  * memory exhaustion.
3326  */
3327 static int add_unformed_module(struct module *mod)
3328 {
3329         int err;
3330         struct module *old;
3331 
3332         mod->state = MODULE_STATE_UNFORMED;
3333 
3334 again:
3335         mutex_lock(&module_mutex);
3336         old = find_module_all(mod->name, strlen(mod->name), true);
3337         if (old != NULL) {
3338                 if (old->state == MODULE_STATE_COMING
3339                     || old->state == MODULE_STATE_UNFORMED) {
3340                         /* Wait in case it fails to load. */
3341                         mutex_unlock(&module_mutex);
3342                         err = wait_event_interruptible(module_wq,
3343                                                finished_loading(mod->name));
3344                         if (err)
3345                                 goto out_unlocked;
3346                         goto again;
3347                 }
3348                 err = -EEXIST;
3349                 goto out;
3350         }
3351         mod_update_bounds(mod);
3352         list_add_rcu(&mod->list, &modules);
3353         mod_tree_insert(mod);
3354         err = 0;
3355 
3356 out:
3357         mutex_unlock(&module_mutex);
3358 out_unlocked:
3359         return err;
3360 }
3361 
3362 static int complete_formation(struct module *mod, struct load_info *info)
3363 {
3364         int err;
3365 
3366         mutex_lock(&module_mutex);
3367 
3368         /* Find duplicate symbols (must be called under lock). */
3369         err = verify_export_symbols(mod);
3370         if (err < 0)
3371                 goto out;
3372 
3373         /* This relies on module_mutex for list integrity. */
3374         module_bug_finalize(info->hdr, info->sechdrs, mod);
3375 
3376         /* Set RO and NX regions for core */
3377         set_section_ro_nx(mod->module_core,
3378                                 mod->core_text_size,
3379                                 mod->core_ro_size,
3380                                 mod->core_size);
3381 
3382         /* Set RO and NX regions for init */
3383         set_section_ro_nx(mod->module_init,
3384                                 mod->init_text_size,
3385                                 mod->init_ro_size,
3386                                 mod->init_size);
3387 
3388         /* Mark state as coming so strong_try_module_get() ignores us,
3389          * but kallsyms etc. can see us. */
3390         mod->state = MODULE_STATE_COMING;
3391         mutex_unlock(&module_mutex);
3392 
3393         blocking_notifier_call_chain(&module_notify_list,
3394                                      MODULE_STATE_COMING, mod);
3395         return 0;
3396 
3397 out:
3398         mutex_unlock(&module_mutex);
3399         return err;
3400 }
3401 
3402 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3403                                    void *arg)
3404 {
3405         struct module *mod = arg;
3406         int ret;
3407 
3408         if (strcmp(param, "async_probe") == 0) {
3409                 mod->async_probe_requested = true;
3410                 return 0;
3411         }
3412 
3413         /* Check for magic 'dyndbg' arg */
3414         ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3415         if (ret != 0)
3416                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3417         return 0;
3418 }
3419 
3420 /* Allocate and load the module: note that size of section 0 is always
3421    zero, and we rely on this for optional sections. */
3422 static int load_module(struct load_info *info, const char __user *uargs,
3423                        int flags)
3424 {
3425         struct module *mod;
3426         long err;
3427         char *after_dashes;
3428 
3429         err = module_sig_check(info);
3430         if (err)
3431                 goto free_copy;
3432 
3433         err = elf_header_check(info);
3434         if (err)
3435                 goto free_copy;
3436 
3437         /* Figure out module layout, and allocate all the memory. */
3438         mod = layout_and_allocate(info, flags);
3439         if (IS_ERR(mod)) {
3440                 err = PTR_ERR(mod);
3441                 goto free_copy;
3442         }
3443 
3444         /* Reserve our place in the list. */
3445         err = add_unformed_module(mod);
3446         if (err)
3447                 goto free_module;
3448 
3449 #ifdef CONFIG_MODULE_SIG
3450         mod->sig_ok = info->sig_ok;
3451         if (!mod->sig_ok) {
3452                 pr_notice_once("%s: module verification failed: signature "
3453                                "and/or required key missing - tainting "
3454                                "kernel\n", mod->name);
3455                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3456         }
3457 #endif
3458 
3459         /* To avoid stressing percpu allocator, do this once we're unique. */
3460         err = percpu_modalloc(mod, info);
3461         if (err)
3462                 goto unlink_mod;
3463 
3464         /* Now module is in final location, initialize linked lists, etc. */
3465         err = module_unload_init(mod);
3466         if (err)
3467                 goto unlink_mod;
3468 
3469         init_param_lock(mod);
3470 
3471         /* Now we've got everything in the final locations, we can
3472          * find optional sections. */
3473         err = find_module_sections(mod, info);
3474         if (err)
3475                 goto free_unload;
3476 
3477         err = check_module_license_and_versions(mod);
3478         if (err)
3479                 goto free_unload;
3480 
3481         /* Set up MODINFO_ATTR fields */
3482         setup_modinfo(mod, info);
3483 
3484         /* Fix up syms, so that st_value is a pointer to location. */
3485         err = simplify_symbols(mod, info);
3486         if (err < 0)
3487                 goto free_modinfo;
3488 
3489         err = apply_relocations(mod, info);
3490         if (err < 0)
3491                 goto free_modinfo;
3492 
3493         err = post_relocation(mod, info);
3494         if (err < 0)
3495                 goto free_modinfo;
3496 
3497         flush_module_icache(mod);
3498 
3499         /* Now copy in args */
3500         mod->args = strndup_user(uargs, ~0UL >> 1);
3501         if (IS_ERR(mod->args)) {
3502                 err = PTR_ERR(mod->args);
3503                 goto free_arch_cleanup;
3504         }
3505 
3506         dynamic_debug_setup(info->debug, info->num_debug);
3507 
3508         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3509         ftrace_module_init(mod);
3510 
3511         /* Finally it's fully formed, ready to start executing. */
3512         err = complete_formation(mod, info);
3513         if (err)
3514                 goto ddebug_cleanup;
3515 
3516         /* Module is ready to execute: parsing args may do that. */
3517         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3518                                   -32768, 32767, NULL,
3519                                   unknown_module_param_cb);
3520         if (IS_ERR(after_dashes)) {
3521                 err = PTR_ERR(after_dashes);
3522                 goto bug_cleanup;
3523         } else if (after_dashes) {
3524                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3525                        mod->name, after_dashes);
3526         }
3527 
3528         /* Link in to syfs. */
3529         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3530         if (err < 0)
3531                 goto bug_cleanup;
3532 
3533         /* Get rid of temporary copy. */
3534         free_copy(info);
3535 
3536         /* Done! */
3537         trace_module_load(mod);
3538 
3539         return do_init_module(mod);
3540 
3541  bug_cleanup:
3542         /* module_bug_cleanup needs module_mutex protection */
3543         mutex_lock(&module_mutex);
3544         module_bug_cleanup(mod);
3545         mutex_unlock(&module_mutex);
3546 
3547         blocking_notifier_call_chain(&module_notify_list,
3548                                      MODULE_STATE_GOING, mod);
3549 
3550         /* we can't deallocate the module until we clear memory protection */
3551         unset_module_init_ro_nx(mod);
3552         unset_module_core_ro_nx(mod);
3553 
3554  ddebug_cleanup:
3555         dynamic_debug_remove(info->debug);
3556         synchronize_sched();
3557         kfree(mod->args);
3558  free_arch_cleanup:
3559         module_arch_cleanup(mod);
3560  free_modinfo:
3561         free_modinfo(mod);
3562  free_unload:
3563         module_unload_free(mod);
3564  unlink_mod:
3565         mutex_lock(&module_mutex);
3566         /* Unlink carefully: kallsyms could be walking list. */
3567         list_del_rcu(&mod->list);
3568         mod_tree_remove(mod);
3569         wake_up_all(&module_wq);
3570         /* Wait for RCU-sched synchronizing before releasing mod->list. */
3571         synchronize_sched();
3572         mutex_unlock(&module_mutex);
3573  free_module:
3574         /*
3575          * Ftrace needs to clean up what it initialized.
3576          * This does nothing if ftrace_module_init() wasn't called,
3577          * but it must be called outside of module_mutex.
3578          */
3579         ftrace_release_mod(mod);
3580         /* Free lock-classes; relies on the preceding sync_rcu() */
3581         lockdep_free_key_range(mod->module_core, mod->core_size);
3582 
3583         module_deallocate(mod, info);
3584  free_copy:
3585         free_copy(info);
3586         return err;
3587 }
3588 
3589 SYSCALL_DEFINE3(init_module, void __user *, umod,
3590                 unsigned long, len, const char __user *, uargs)
3591 {
3592         int err;
3593         struct load_info info = { };
3594 
3595         err = may_init_module();
3596         if (err)
3597                 return err;
3598 
3599         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3600                umod, len, uargs);
3601 
3602         err = copy_module_from_user(umod, len, &info);
3603         if (err)
3604                 return err;
3605 
3606         return load_module(&info, uargs, 0);
3607 }
3608 
3609 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3610 {
3611         int err;
3612         struct load_info info = { };
3613 
3614         err = may_init_module();
3615         if (err)
3616                 return err;
3617 
3618         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3619 
3620         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3621                       |MODULE_INIT_IGNORE_VERMAGIC))
3622                 return -EINVAL;
3623 
3624         err = copy_module_from_fd(fd, &info);
3625         if (err)
3626                 return err;
3627 
3628         return load_module(&info, uargs, flags);
3629 }
3630 
3631 static inline int within(unsigned long addr, void *start, unsigned long size)
3632 {
3633         return ((void *)addr >= start && (void *)addr < start + size);
3634 }
3635 
3636 #ifdef CONFIG_KALLSYMS
3637 /*
3638  * This ignores the intensely annoying "mapping symbols" found
3639  * in ARM ELF files: $a, $t and $d.
3640  */
3641 static inline int is_arm_mapping_symbol(const char *str)
3642 {
3643         if (str[0] == '.' && str[1] == 'L')
3644                 return true;
3645         return str[0] == '$' && strchr("axtd", str[1])
3646                && (str[2] == '\0' || str[2] == '.');
3647 }
3648 
3649 static const char *get_ksymbol(struct module *mod,
3650                                unsigned long addr,
3651                                unsigned long *size,
3652                                unsigned long *offset)
3653 {
3654         unsigned int i, best = 0;
3655         unsigned long nextval;
3656 
3657         /* At worse, next value is at end of module */
3658         if (within_module_init(addr, mod))
3659                 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3660         else
3661                 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3662 
3663         /* Scan for closest preceding symbol, and next symbol. (ELF
3664            starts real symbols at 1). */
3665         for (i = 1; i < mod->num_symtab; i++) {
3666                 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3667                         continue;
3668 
3669                 /* We ignore unnamed symbols: they're uninformative
3670                  * and inserted at a whim. */
3671                 if (mod->symtab[i].st_value <= addr
3672                     && mod->symtab[i].st_value > mod->symtab[best].st_value
3673                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3674                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3675                         best = i;
3676                 if (mod->symtab[i].st_value > addr
3677                     && mod->symtab[i].st_value < nextval
3678                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3679                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3680                         nextval = mod->symtab[i].st_value;
3681         }
3682 
3683         if (!best)
3684                 return NULL;
3685 
3686         if (size)
3687                 *size = nextval - mod->symtab[best].st_value;
3688         if (offset)
3689                 *offset = addr - mod->symtab[best].st_value;
3690         return mod->strtab + mod->symtab[best].st_name;
3691 }
3692 
3693 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3694  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3695 const char *module_address_lookup(unsigned long addr,
3696                             unsigned long *size,
3697                             unsigned long *offset,
3698                             char **modname,
3699                             char *namebuf)
3700 {
3701         const char *ret = NULL;
3702         struct module *mod;
3703 
3704         preempt_disable();
3705         mod = __module_address(addr);
3706         if (mod) {
3707                 if (modname)
3708                         *modname = mod->name;
3709                 ret = get_ksymbol(mod, addr, size, offset);
3710         }
3711         /* Make a copy in here where it's safe */
3712         if (ret) {
3713                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3714                 ret = namebuf;
3715         }
3716         preempt_enable();
3717 
3718         return ret;
3719 }
3720 
3721 int lookup_module_symbol_name(unsigned long addr, char *symname)
3722 {
3723         struct module *mod;
3724 
3725         preempt_disable();
3726         list_for_each_entry_rcu(mod, &modules, list) {
3727                 if (mod->state == MODULE_STATE_UNFORMED)
3728                         continue;
3729                 if (within_module(addr, mod)) {
3730                         const char *sym;
3731 
3732                         sym = get_ksymbol(mod, addr, NULL, NULL);
3733                         if (!sym)
3734                                 goto out;
3735                         strlcpy(symname, sym, KSYM_NAME_LEN);
3736                         preempt_enable();
3737                         return 0;
3738                 }
3739         }
3740 out:
3741         preempt_enable();
3742         return -ERANGE;
3743 }
3744 
3745 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3746                         unsigned long *offset, char *modname, char *name)
3747 {
3748         struct module *mod;
3749 
3750         preempt_disable();
3751         list_for_each_entry_rcu(mod, &modules, list) {
3752                 if (mod->state == MODULE_STATE_UNFORMED)
3753                         continue;
3754                 if (within_module(addr, mod)) {
3755                         const char *sym;
3756 
3757                         sym = get_ksymbol(mod, addr, size, offset);
3758                         if (!sym)
3759                                 goto out;
3760                         if (modname)
3761                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3762                         if (name)
3763                                 strlcpy(name, sym, KSYM_NAME_LEN);
3764                         preempt_enable();
3765                         return 0;
3766                 }
3767         }
3768 out:
3769         preempt_enable();
3770         return -ERANGE;
3771 }
3772 
3773 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3774                         char *name, char *module_name, int *exported)
3775 {
3776         struct module *mod;
3777 
3778         preempt_disable();
3779         list_for_each_entry_rcu(mod, &modules, list) {
3780                 if (mod->state == MODULE_STATE_UNFORMED)
3781                         continue;
3782                 if (symnum < mod->num_symtab) {
3783                         *value = mod->symtab[symnum].st_value;
3784                         *type = mod->symtab[symnum].st_info;
3785                         strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3786                                 KSYM_NAME_LEN);
3787                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3788                         *exported = is_exported(name, *value, mod);
3789                         preempt_enable();
3790                         return 0;
3791                 }
3792                 symnum -= mod->num_symtab;
3793         }
3794         preempt_enable();
3795         return -ERANGE;
3796 }
3797 
3798 static unsigned long mod_find_symname(struct module *mod, const char *name)
3799 {
3800         unsigned int i;
3801 
3802         for (i = 0; i < mod->num_symtab; i++)
3803                 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3804                     mod->symtab[i].st_info != 'U')
3805                         return mod->symtab[i].st_value;
3806         return 0;
3807 }
3808 
3809 /* Look for this name: can be of form module:name. */
3810 unsigned long module_kallsyms_lookup_name(const char *name)
3811 {
3812         struct module *mod;
3813         char *colon;
3814         unsigned long ret = 0;
3815 
3816         /* Don't lock: we're in enough trouble already. */
3817         preempt_disable();
3818         if ((colon = strchr(name, ':')) != NULL) {
3819                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3820                         ret = mod_find_symname(mod, colon+1);
3821         } else {
3822                 list_for_each_entry_rcu(mod, &modules, list) {
3823                         if (mod->state == MODULE_STATE_UNFORMED)
3824                                 continue;
3825                         if ((ret = mod_find_symname(mod, name)) != 0)
3826                                 break;
3827                 }
3828         }
3829         preempt_enable();
3830         return ret;
3831 }
3832 
3833 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3834                                              struct module *, unsigned long),
3835                                    void *data)
3836 {
3837         struct module *mod;
3838         unsigned int i;
3839         int ret;
3840 
3841         module_assert_mutex();
3842 
3843         list_for_each_entry(mod, &modules, list) {
3844                 if (mod->state == MODULE_STATE_UNFORMED)
3845                         continue;
3846                 for (i = 0; i < mod->num_symtab; i++) {
3847                         ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3848                                  mod, mod->symtab[i].st_value);
3849                         if (ret != 0)
3850                                 return ret;
3851                 }
3852         }
3853         return 0;
3854 }
3855 #endif /* CONFIG_KALLSYMS */
3856 
3857 static char *module_flags(struct module *mod, char *buf)
3858 {
3859         int bx = 0;
3860 
3861         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3862         if (mod->taints ||
3863             mod->state == MODULE_STATE_GOING ||
3864             mod->state == MODULE_STATE_COMING) {
3865                 buf[bx++] = '(';
3866                 bx += module_flags_taint(mod, buf + bx);
3867                 /* Show a - for module-is-being-unloaded */
3868                 if (mod->state == MODULE_STATE_GOING)
3869                         buf[bx++] = '-';
3870                 /* Show a + for module-is-being-loaded */
3871                 if (mod->state == MODULE_STATE_COMING)
3872                         buf[bx++] = '+';
3873                 buf[bx++] = ')';
3874         }
3875         buf[bx] = '\0';
3876 
3877         return buf;
3878 }
3879 
3880 #ifdef CONFIG_PROC_FS
3881 /* Called by the /proc file system to return a list of modules. */
3882 static void *m_start(struct seq_file *m, loff_t *pos)
3883 {
3884         mutex_lock(&module_mutex);
3885         return seq_list_start(&modules, *pos);
3886 }
3887 
3888 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3889 {
3890         return seq_list_next(p, &modules, pos);
3891 }
3892 
3893 static void m_stop(struct seq_file *m, void *p)
3894 {
3895         mutex_unlock(&module_mutex);
3896 }
3897 
3898 static int m_show(struct seq_file *m, void *p)
3899 {
3900         struct module *mod = list_entry(p, struct module, list);
3901         char buf[8];
3902 
3903         /* We always ignore unformed modules. */
3904         if (mod->state == MODULE_STATE_UNFORMED)
3905                 return 0;
3906 
3907         seq_printf(m, "%s %u",
3908                    mod->name, mod->init_size + mod->core_size);
3909         print_unload_info(m, mod);
3910 
3911         /* Informative for users. */
3912         seq_printf(m, " %s",
3913                    mod->state == MODULE_STATE_GOING ? "Unloading" :
3914                    mod->state == MODULE_STATE_COMING ? "Loading" :
3915                    "Live");
3916         /* Used by oprofile and other similar tools. */
3917         seq_printf(m, " 0x%pK", mod->module_core);
3918 
3919         /* Taints info */
3920         if (mod->taints)
3921                 seq_printf(m, " %s", module_flags(mod, buf));
3922 
3923         seq_puts(m, "\n");
3924         return 0;
3925 }
3926 
3927 /* Format: modulename size refcount deps address
3928 
3929    Where refcount is a number or -, and deps is a comma-separated list
3930    of depends or -.
3931 */
3932 static const struct seq_operations modules_op = {
3933         .start  = m_start,
3934         .next   = m_next,
3935         .stop   = m_stop,
3936         .show   = m_show
3937 };
3938 
3939 static int modules_open(struct inode *inode, struct file *file)
3940 {
3941         return seq_open(file, &modules_op);
3942 }
3943 
3944 static const struct file_operations proc_modules_operations = {
3945         .open           = modules_open,
3946         .read           = seq_read,
3947         .llseek         = seq_lseek,
3948         .release        = seq_release,
3949 };
3950 
3951 static int __init proc_modules_init(void)
3952 {
3953         proc_create("modules", 0, NULL, &proc_modules_operations);
3954         return 0;
3955 }
3956 module_init(proc_modules_init);
3957 #endif
3958 
3959 /* Given an address, look for it in the module exception tables. */
3960 const struct exception_table_entry *search_module_extables(unsigned long addr)
3961 {
3962         const struct exception_table_entry *e = NULL;
3963         struct module *mod;
3964 
3965         preempt_disable();
3966         list_for_each_entry_rcu(mod, &modules, list) {
3967                 if (mod->state == MODULE_STATE_UNFORMED)
3968                         continue;
3969                 if (mod->num_exentries == 0)
3970                         continue;
3971 
3972                 e = search_extable(mod->extable,
3973                                    mod->extable + mod->num_exentries - 1,
3974                                    addr);
3975                 if (e)
3976                         break;
3977         }
3978         preempt_enable();
3979 
3980         /* Now, if we found one, we are running inside it now, hence
3981            we cannot unload the module, hence no refcnt needed. */
3982         return e;
3983 }
3984 
3985 /*
3986  * is_module_address - is this address inside a module?
3987  * @addr: the address to check.
3988  *
3989  * See is_module_text_address() if you simply want to see if the address
3990  * is code (not data).
3991  */
3992 bool is_module_address(unsigned long addr)
3993 {
3994         bool ret;
3995 
3996         preempt_disable();
3997         ret = __module_address(addr) != NULL;
3998         preempt_enable();
3999 
4000         return ret;
4001 }
4002 
4003 /*
4004  * __module_address - get the module which contains an address.
4005  * @addr: the address.
4006  *
4007  * Must be called with preempt disabled or module mutex held so that
4008  * module doesn't get freed during this.
4009  */
4010 struct module *__module_address(unsigned long addr)
4011 {
4012         struct module *mod;
4013 
4014         if (addr < module_addr_min || addr > module_addr_max)
4015                 return NULL;
4016 
4017         module_assert_mutex_or_preempt();
4018 
4019         mod = mod_find(addr);
4020         if (mod) {
4021                 BUG_ON(!within_module(addr, mod));
4022                 if (mod->state == MODULE_STATE_UNFORMED)
4023                         mod = NULL;
4024         }
4025         return mod;
4026 }
4027 EXPORT_SYMBOL_GPL(__module_address);
4028 
4029 /*
4030  * is_module_text_address - is this address inside module code?
4031  * @addr: the address to check.
4032  *
4033  * See is_module_address() if you simply want to see if the address is
4034  * anywhere in a module.  See kernel_text_address() for testing if an
4035  * address corresponds to kernel or module code.
4036  */
4037 bool is_module_text_address(unsigned long addr)
4038 {
4039         bool ret;
4040 
4041         preempt_disable();
4042         ret = __module_text_address(addr) != NULL;
4043         preempt_enable();
4044 
4045         return ret;
4046 }
4047 
4048 /*
4049  * __module_text_address - get the module whose code contains an address.
4050  * @addr: the address.
4051  *
4052  * Must be called with preempt disabled or module mutex held so that
4053  * module doesn't get freed during this.
4054  */
4055 struct module *__module_text_address(unsigned long addr)
4056 {
4057         struct module *mod = __module_address(addr);
4058         if (mod) {
4059                 /* Make sure it's within the text section. */
4060                 if (!within(addr, mod->module_init, mod->init_text_size)
4061                     && !within(addr, mod->module_core, mod->core_text_size))
4062                         mod = NULL;
4063         }
4064         return mod;
4065 }
4066 EXPORT_SYMBOL_GPL(__module_text_address);
4067 
4068 /* Don't grab lock, we're oopsing. */
4069 void print_modules(void)
4070 {
4071         struct module *mod;
4072         char buf[8];
4073 
4074         printk(KERN_DEFAULT "Modules linked in:");
4075         /* Most callers should already have preempt disabled, but make sure */
4076         preempt_disable();
4077         list_for_each_entry_rcu(mod, &modules, list) {
4078                 if (mod->state == MODULE_STATE_UNFORMED)
4079                         continue;
4080                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4081         }
4082         preempt_enable();
4083         if (last_unloaded_module[0])
4084                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4085         pr_cont("\n");
4086 }
4087 
4088 #ifdef CONFIG_MODVERSIONS
4089 /* Generate the signature for all relevant module structures here.
4090  * If these change, we don't want to try to parse the module. */
4091 void module_layout(struct module *mod,
4092                    struct modversion_info *ver,
4093                    struct kernel_param *kp,
4094                    struct kernel_symbol *ks,
4095                    struct tracepoint * const *tp)
4096 {
4097 }
4098 EXPORT_SYMBOL(module_layout);
4099 #endif
4100 

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