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TOMOYO Linux Cross Reference
Linux/kernel/module.c

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  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 <linux/uaccess.h>
 50 #include <asm/cacheflush.h>
 51 #include <asm/mmu_context.h>
 52 #include <linux/license.h>
 53 #include <asm/sections.h>
 54 #include <linux/tracepoint.h>
 55 #include <linux/ftrace.h>
 56 #include <linux/livepatch.h>
 57 #include <linux/async.h>
 58 #include <linux/percpu.h>
 59 #include <linux/kmemleak.h>
 60 #include <linux/jump_label.h>
 61 #include <linux/pfn.h>
 62 #include <linux/bsearch.h>
 63 #include <linux/dynamic_debug.h>
 64 #include <uapi/linux/module.h>
 65 #include "module-internal.h"
 66 #include <linux/ccsecurity.h>
 67 
 68 #define CREATE_TRACE_POINTS
 69 #include <trace/events/module.h>
 70 
 71 #ifndef ARCH_SHF_SMALL
 72 #define ARCH_SHF_SMALL 0
 73 #endif
 74 
 75 /*
 76  * Modules' sections will be aligned on page boundaries
 77  * to ensure complete separation of code and data, but
 78  * only when CONFIG_DEBUG_SET_MODULE_RONX=y
 79  */
 80 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 81 # define debug_align(X) ALIGN(X, PAGE_SIZE)
 82 #else
 83 # define debug_align(X) (X)
 84 #endif
 85 
 86 /* If this is set, the section belongs in the init part of the module */
 87 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
 88 
 89 /*
 90  * Mutex protects:
 91  * 1) List of modules (also safely readable with preempt_disable),
 92  * 2) module_use links,
 93  * 3) module_addr_min/module_addr_max.
 94  * (delete and add uses RCU list operations). */
 95 DEFINE_MUTEX(module_mutex);
 96 EXPORT_SYMBOL_GPL(module_mutex);
 97 static LIST_HEAD(modules);
 98 
 99 #ifdef CONFIG_MODULES_TREE_LOOKUP
100 
101 /*
102  * Use a latched RB-tree for __module_address(); this allows us to use
103  * RCU-sched lookups of the address from any context.
104  *
105  * This is conditional on PERF_EVENTS || TRACING because those can really hit
106  * __module_address() hard by doing a lot of stack unwinding; potentially from
107  * NMI context.
108  */
109 
110 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
111 {
112         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
113 
114         return (unsigned long)layout->base;
115 }
116 
117 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
118 {
119         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
120 
121         return (unsigned long)layout->size;
122 }
123 
124 static __always_inline bool
125 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
126 {
127         return __mod_tree_val(a) < __mod_tree_val(b);
128 }
129 
130 static __always_inline int
131 mod_tree_comp(void *key, struct latch_tree_node *n)
132 {
133         unsigned long val = (unsigned long)key;
134         unsigned long start, end;
135 
136         start = __mod_tree_val(n);
137         if (val < start)
138                 return -1;
139 
140         end = start + __mod_tree_size(n);
141         if (val >= end)
142                 return 1;
143 
144         return 0;
145 }
146 
147 static const struct latch_tree_ops mod_tree_ops = {
148         .less = mod_tree_less,
149         .comp = mod_tree_comp,
150 };
151 
152 static struct mod_tree_root {
153         struct latch_tree_root root;
154         unsigned long addr_min;
155         unsigned long addr_max;
156 } mod_tree __cacheline_aligned = {
157         .addr_min = -1UL,
158 };
159 
160 #define module_addr_min mod_tree.addr_min
161 #define module_addr_max mod_tree.addr_max
162 
163 static noinline void __mod_tree_insert(struct mod_tree_node *node)
164 {
165         latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
166 }
167 
168 static void __mod_tree_remove(struct mod_tree_node *node)
169 {
170         latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
171 }
172 
173 /*
174  * These modifications: insert, remove_init and remove; are serialized by the
175  * module_mutex.
176  */
177 static void mod_tree_insert(struct module *mod)
178 {
179         mod->core_layout.mtn.mod = mod;
180         mod->init_layout.mtn.mod = mod;
181 
182         __mod_tree_insert(&mod->core_layout.mtn);
183         if (mod->init_layout.size)
184                 __mod_tree_insert(&mod->init_layout.mtn);
185 }
186 
187 static void mod_tree_remove_init(struct module *mod)
188 {
189         if (mod->init_layout.size)
190                 __mod_tree_remove(&mod->init_layout.mtn);
191 }
192 
193 static void mod_tree_remove(struct module *mod)
194 {
195         __mod_tree_remove(&mod->core_layout.mtn);
196         mod_tree_remove_init(mod);
197 }
198 
199 static struct module *mod_find(unsigned long addr)
200 {
201         struct latch_tree_node *ltn;
202 
203         ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
204         if (!ltn)
205                 return NULL;
206 
207         return container_of(ltn, struct mod_tree_node, node)->mod;
208 }
209 
210 #else /* MODULES_TREE_LOOKUP */
211 
212 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
213 
214 static void mod_tree_insert(struct module *mod) { }
215 static void mod_tree_remove_init(struct module *mod) { }
216 static void mod_tree_remove(struct module *mod) { }
217 
218 static struct module *mod_find(unsigned long addr)
219 {
220         struct module *mod;
221 
222         list_for_each_entry_rcu(mod, &modules, list) {
223                 if (within_module(addr, mod))
224                         return mod;
225         }
226 
227         return NULL;
228 }
229 
230 #endif /* MODULES_TREE_LOOKUP */
231 
232 /*
233  * Bounds of module text, for speeding up __module_address.
234  * Protected by module_mutex.
235  */
236 static void __mod_update_bounds(void *base, unsigned int size)
237 {
238         unsigned long min = (unsigned long)base;
239         unsigned long max = min + size;
240 
241         if (min < module_addr_min)
242                 module_addr_min = min;
243         if (max > module_addr_max)
244                 module_addr_max = max;
245 }
246 
247 static void mod_update_bounds(struct module *mod)
248 {
249         __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
250         if (mod->init_layout.size)
251                 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
252 }
253 
254 #ifdef CONFIG_KGDB_KDB
255 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
256 #endif /* CONFIG_KGDB_KDB */
257 
258 static void module_assert_mutex(void)
259 {
260         lockdep_assert_held(&module_mutex);
261 }
262 
263 static void module_assert_mutex_or_preempt(void)
264 {
265 #ifdef CONFIG_LOCKDEP
266         if (unlikely(!debug_locks))
267                 return;
268 
269         WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
270                 !lockdep_is_held(&module_mutex));
271 #endif
272 }
273 
274 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
275 #ifndef CONFIG_MODULE_SIG_FORCE
276 module_param(sig_enforce, bool_enable_only, 0644);
277 #endif /* !CONFIG_MODULE_SIG_FORCE */
278 
279 /* Block module loading/unloading? */
280 int modules_disabled = 0;
281 core_param(nomodule, modules_disabled, bint, 0);
282 
283 /* Waiting for a module to finish initializing? */
284 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
285 
286 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
287 
288 int register_module_notifier(struct notifier_block *nb)
289 {
290         return blocking_notifier_chain_register(&module_notify_list, nb);
291 }
292 EXPORT_SYMBOL(register_module_notifier);
293 
294 int unregister_module_notifier(struct notifier_block *nb)
295 {
296         return blocking_notifier_chain_unregister(&module_notify_list, nb);
297 }
298 EXPORT_SYMBOL(unregister_module_notifier);
299 
300 struct load_info {
301         Elf_Ehdr *hdr;
302         unsigned long len;
303         Elf_Shdr *sechdrs;
304         char *secstrings, *strtab;
305         unsigned long symoffs, stroffs;
306         struct _ddebug *debug;
307         unsigned int num_debug;
308         bool sig_ok;
309 #ifdef CONFIG_KALLSYMS
310         unsigned long mod_kallsyms_init_off;
311 #endif
312         struct {
313                 unsigned int sym, str, mod, vers, info, pcpu;
314         } index;
315 };
316 
317 /*
318  * We require a truly strong try_module_get(): 0 means success.
319  * Otherwise an error is returned due to ongoing or failed
320  * initialization etc.
321  */
322 static inline int strong_try_module_get(struct module *mod)
323 {
324         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
325         if (mod && mod->state == MODULE_STATE_COMING)
326                 return -EBUSY;
327         if (try_module_get(mod))
328                 return 0;
329         else
330                 return -ENOENT;
331 }
332 
333 static inline void add_taint_module(struct module *mod, unsigned flag,
334                                     enum lockdep_ok lockdep_ok)
335 {
336         add_taint(flag, lockdep_ok);
337         set_bit(flag, &mod->taints);
338 }
339 
340 /*
341  * A thread that wants to hold a reference to a module only while it
342  * is running can call this to safely exit.  nfsd and lockd use this.
343  */
344 void __noreturn __module_put_and_exit(struct module *mod, long code)
345 {
346         module_put(mod);
347         do_exit(code);
348 }
349 EXPORT_SYMBOL(__module_put_and_exit);
350 
351 /* Find a module section: 0 means not found. */
352 static unsigned int find_sec(const struct load_info *info, const char *name)
353 {
354         unsigned int i;
355 
356         for (i = 1; i < info->hdr->e_shnum; i++) {
357                 Elf_Shdr *shdr = &info->sechdrs[i];
358                 /* Alloc bit cleared means "ignore it." */
359                 if ((shdr->sh_flags & SHF_ALLOC)
360                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
361                         return i;
362         }
363         return 0;
364 }
365 
366 /* Find a module section, or NULL. */
367 static void *section_addr(const struct load_info *info, const char *name)
368 {
369         /* Section 0 has sh_addr 0. */
370         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
371 }
372 
373 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
374 static void *section_objs(const struct load_info *info,
375                           const char *name,
376                           size_t object_size,
377                           unsigned int *num)
378 {
379         unsigned int sec = find_sec(info, name);
380 
381         /* Section 0 has sh_addr 0 and sh_size 0. */
382         *num = info->sechdrs[sec].sh_size / object_size;
383         return (void *)info->sechdrs[sec].sh_addr;
384 }
385 
386 /* Provided by the linker */
387 extern const struct kernel_symbol __start___ksymtab[];
388 extern const struct kernel_symbol __stop___ksymtab[];
389 extern const struct kernel_symbol __start___ksymtab_gpl[];
390 extern const struct kernel_symbol __stop___ksymtab_gpl[];
391 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
392 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
393 extern const s32 __start___kcrctab[];
394 extern const s32 __start___kcrctab_gpl[];
395 extern const s32 __start___kcrctab_gpl_future[];
396 #ifdef CONFIG_UNUSED_SYMBOLS
397 extern const struct kernel_symbol __start___ksymtab_unused[];
398 extern const struct kernel_symbol __stop___ksymtab_unused[];
399 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
400 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
401 extern const s32 __start___kcrctab_unused[];
402 extern const s32 __start___kcrctab_unused_gpl[];
403 #endif
404 
405 #ifndef CONFIG_MODVERSIONS
406 #define symversion(base, idx) NULL
407 #else
408 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
409 #endif
410 
411 static bool each_symbol_in_section(const struct symsearch *arr,
412                                    unsigned int arrsize,
413                                    struct module *owner,
414                                    bool (*fn)(const struct symsearch *syms,
415                                               struct module *owner,
416                                               void *data),
417                                    void *data)
418 {
419         unsigned int j;
420 
421         for (j = 0; j < arrsize; j++) {
422                 if (fn(&arr[j], owner, data))
423                         return true;
424         }
425 
426         return false;
427 }
428 
429 /* Returns true as soon as fn returns true, otherwise false. */
430 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
431                                     struct module *owner,
432                                     void *data),
433                          void *data)
434 {
435         struct module *mod;
436         static const struct symsearch arr[] = {
437                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
438                   NOT_GPL_ONLY, false },
439                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
440                   __start___kcrctab_gpl,
441                   GPL_ONLY, false },
442                 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
443                   __start___kcrctab_gpl_future,
444                   WILL_BE_GPL_ONLY, false },
445 #ifdef CONFIG_UNUSED_SYMBOLS
446                 { __start___ksymtab_unused, __stop___ksymtab_unused,
447                   __start___kcrctab_unused,
448                   NOT_GPL_ONLY, true },
449                 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
450                   __start___kcrctab_unused_gpl,
451                   GPL_ONLY, true },
452 #endif
453         };
454 
455         module_assert_mutex_or_preempt();
456 
457         if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
458                 return true;
459 
460         list_for_each_entry_rcu(mod, &modules, list) {
461                 struct symsearch arr[] = {
462                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
463                           NOT_GPL_ONLY, false },
464                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
465                           mod->gpl_crcs,
466                           GPL_ONLY, false },
467                         { mod->gpl_future_syms,
468                           mod->gpl_future_syms + mod->num_gpl_future_syms,
469                           mod->gpl_future_crcs,
470                           WILL_BE_GPL_ONLY, false },
471 #ifdef CONFIG_UNUSED_SYMBOLS
472                         { mod->unused_syms,
473                           mod->unused_syms + mod->num_unused_syms,
474                           mod->unused_crcs,
475                           NOT_GPL_ONLY, true },
476                         { mod->unused_gpl_syms,
477                           mod->unused_gpl_syms + mod->num_unused_gpl_syms,
478                           mod->unused_gpl_crcs,
479                           GPL_ONLY, true },
480 #endif
481                 };
482 
483                 if (mod->state == MODULE_STATE_UNFORMED)
484                         continue;
485 
486                 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
487                         return true;
488         }
489         return false;
490 }
491 EXPORT_SYMBOL_GPL(each_symbol_section);
492 
493 struct find_symbol_arg {
494         /* Input */
495         const char *name;
496         bool gplok;
497         bool warn;
498 
499         /* Output */
500         struct module *owner;
501         const s32 *crc;
502         const struct kernel_symbol *sym;
503 };
504 
505 static bool check_symbol(const struct symsearch *syms,
506                                  struct module *owner,
507                                  unsigned int symnum, void *data)
508 {
509         struct find_symbol_arg *fsa = data;
510 
511         if (!fsa->gplok) {
512                 if (syms->licence == GPL_ONLY)
513                         return false;
514                 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
515                         pr_warn("Symbol %s is being used by a non-GPL module, "
516                                 "which will not be allowed in the future\n",
517                                 fsa->name);
518                 }
519         }
520 
521 #ifdef CONFIG_UNUSED_SYMBOLS
522         if (syms->unused && fsa->warn) {
523                 pr_warn("Symbol %s is marked as UNUSED, however this module is "
524                         "using it.\n", fsa->name);
525                 pr_warn("This symbol will go away in the future.\n");
526                 pr_warn("Please evaluate if this is the right api to use and "
527                         "if it really is, submit a report to the linux kernel "
528                         "mailing list together with submitting your code for "
529                         "inclusion.\n");
530         }
531 #endif
532 
533         fsa->owner = owner;
534         fsa->crc = symversion(syms->crcs, symnum);
535         fsa->sym = &syms->start[symnum];
536         return true;
537 }
538 
539 static int cmp_name(const void *va, const void *vb)
540 {
541         const char *a;
542         const struct kernel_symbol *b;
543         a = va; b = vb;
544         return strcmp(a, b->name);
545 }
546 
547 static bool find_symbol_in_section(const struct symsearch *syms,
548                                    struct module *owner,
549                                    void *data)
550 {
551         struct find_symbol_arg *fsa = data;
552         struct kernel_symbol *sym;
553 
554         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
555                         sizeof(struct kernel_symbol), cmp_name);
556 
557         if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
558                 return true;
559 
560         return false;
561 }
562 
563 /* Find a symbol and return it, along with, (optional) crc and
564  * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
565 const struct kernel_symbol *find_symbol(const char *name,
566                                         struct module **owner,
567                                         const s32 **crc,
568                                         bool gplok,
569                                         bool warn)
570 {
571         struct find_symbol_arg fsa;
572 
573         fsa.name = name;
574         fsa.gplok = gplok;
575         fsa.warn = warn;
576 
577         if (each_symbol_section(find_symbol_in_section, &fsa)) {
578                 if (owner)
579                         *owner = fsa.owner;
580                 if (crc)
581                         *crc = fsa.crc;
582                 return fsa.sym;
583         }
584 
585         pr_debug("Failed to find symbol %s\n", name);
586         return NULL;
587 }
588 EXPORT_SYMBOL_GPL(find_symbol);
589 
590 /*
591  * Search for module by name: must hold module_mutex (or preempt disabled
592  * for read-only access).
593  */
594 static struct module *find_module_all(const char *name, size_t len,
595                                       bool even_unformed)
596 {
597         struct module *mod;
598 
599         module_assert_mutex_or_preempt();
600 
601         list_for_each_entry(mod, &modules, list) {
602                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
603                         continue;
604                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
605                         return mod;
606         }
607         return NULL;
608 }
609 
610 struct module *find_module(const char *name)
611 {
612         module_assert_mutex();
613         return find_module_all(name, strlen(name), false);
614 }
615 EXPORT_SYMBOL_GPL(find_module);
616 
617 #ifdef CONFIG_SMP
618 
619 static inline void __percpu *mod_percpu(struct module *mod)
620 {
621         return mod->percpu;
622 }
623 
624 static int percpu_modalloc(struct module *mod, struct load_info *info)
625 {
626         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
627         unsigned long align = pcpusec->sh_addralign;
628 
629         if (!pcpusec->sh_size)
630                 return 0;
631 
632         if (align > PAGE_SIZE) {
633                 pr_warn("%s: per-cpu alignment %li > %li\n",
634                         mod->name, align, PAGE_SIZE);
635                 align = PAGE_SIZE;
636         }
637 
638         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
639         if (!mod->percpu) {
640                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
641                         mod->name, (unsigned long)pcpusec->sh_size);
642                 return -ENOMEM;
643         }
644         mod->percpu_size = pcpusec->sh_size;
645         return 0;
646 }
647 
648 static void percpu_modfree(struct module *mod)
649 {
650         free_percpu(mod->percpu);
651 }
652 
653 static unsigned int find_pcpusec(struct load_info *info)
654 {
655         return find_sec(info, ".data..percpu");
656 }
657 
658 static void percpu_modcopy(struct module *mod,
659                            const void *from, unsigned long size)
660 {
661         int cpu;
662 
663         for_each_possible_cpu(cpu)
664                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
665 }
666 
667 /**
668  * is_module_percpu_address - test whether address is from module static percpu
669  * @addr: address to test
670  *
671  * Test whether @addr belongs to module static percpu area.
672  *
673  * RETURNS:
674  * %true if @addr is from module static percpu area
675  */
676 bool is_module_percpu_address(unsigned long addr)
677 {
678         struct module *mod;
679         unsigned int cpu;
680 
681         preempt_disable();
682 
683         list_for_each_entry_rcu(mod, &modules, list) {
684                 if (mod->state == MODULE_STATE_UNFORMED)
685                         continue;
686                 if (!mod->percpu_size)
687                         continue;
688                 for_each_possible_cpu(cpu) {
689                         void *start = per_cpu_ptr(mod->percpu, cpu);
690 
691                         if ((void *)addr >= start &&
692                             (void *)addr < start + mod->percpu_size) {
693                                 preempt_enable();
694                                 return true;
695                         }
696                 }
697         }
698 
699         preempt_enable();
700         return false;
701 }
702 
703 #else /* ... !CONFIG_SMP */
704 
705 static inline void __percpu *mod_percpu(struct module *mod)
706 {
707         return NULL;
708 }
709 static int percpu_modalloc(struct module *mod, struct load_info *info)
710 {
711         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
712         if (info->sechdrs[info->index.pcpu].sh_size != 0)
713                 return -ENOMEM;
714         return 0;
715 }
716 static inline void percpu_modfree(struct module *mod)
717 {
718 }
719 static unsigned int find_pcpusec(struct load_info *info)
720 {
721         return 0;
722 }
723 static inline void percpu_modcopy(struct module *mod,
724                                   const void *from, unsigned long size)
725 {
726         /* pcpusec should be 0, and size of that section should be 0. */
727         BUG_ON(size != 0);
728 }
729 bool is_module_percpu_address(unsigned long addr)
730 {
731         return false;
732 }
733 
734 #endif /* CONFIG_SMP */
735 
736 #define MODINFO_ATTR(field)     \
737 static void setup_modinfo_##field(struct module *mod, const char *s)  \
738 {                                                                     \
739         mod->field = kstrdup(s, GFP_KERNEL);                          \
740 }                                                                     \
741 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
742                         struct module_kobject *mk, char *buffer)      \
743 {                                                                     \
744         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
745 }                                                                     \
746 static int modinfo_##field##_exists(struct module *mod)               \
747 {                                                                     \
748         return mod->field != NULL;                                    \
749 }                                                                     \
750 static void free_modinfo_##field(struct module *mod)                  \
751 {                                                                     \
752         kfree(mod->field);                                            \
753         mod->field = NULL;                                            \
754 }                                                                     \
755 static struct module_attribute modinfo_##field = {                    \
756         .attr = { .name = __stringify(field), .mode = 0444 },         \
757         .show = show_modinfo_##field,                                 \
758         .setup = setup_modinfo_##field,                               \
759         .test = modinfo_##field##_exists,                             \
760         .free = free_modinfo_##field,                                 \
761 };
762 
763 MODINFO_ATTR(version);
764 MODINFO_ATTR(srcversion);
765 
766 static char last_unloaded_module[MODULE_NAME_LEN+1];
767 
768 #ifdef CONFIG_MODULE_UNLOAD
769 
770 EXPORT_TRACEPOINT_SYMBOL(module_get);
771 
772 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
773 #define MODULE_REF_BASE 1
774 
775 /* Init the unload section of the module. */
776 static int module_unload_init(struct module *mod)
777 {
778         /*
779          * Initialize reference counter to MODULE_REF_BASE.
780          * refcnt == 0 means module is going.
781          */
782         atomic_set(&mod->refcnt, MODULE_REF_BASE);
783 
784         INIT_LIST_HEAD(&mod->source_list);
785         INIT_LIST_HEAD(&mod->target_list);
786 
787         /* Hold reference count during initialization. */
788         atomic_inc(&mod->refcnt);
789 
790         return 0;
791 }
792 
793 /* Does a already use b? */
794 static int already_uses(struct module *a, struct module *b)
795 {
796         struct module_use *use;
797 
798         list_for_each_entry(use, &b->source_list, source_list) {
799                 if (use->source == a) {
800                         pr_debug("%s uses %s!\n", a->name, b->name);
801                         return 1;
802                 }
803         }
804         pr_debug("%s does not use %s!\n", a->name, b->name);
805         return 0;
806 }
807 
808 /*
809  * Module a uses b
810  *  - we add 'a' as a "source", 'b' as a "target" of module use
811  *  - the module_use is added to the list of 'b' sources (so
812  *    'b' can walk the list to see who sourced them), and of 'a'
813  *    targets (so 'a' can see what modules it targets).
814  */
815 static int add_module_usage(struct module *a, struct module *b)
816 {
817         struct module_use *use;
818 
819         pr_debug("Allocating new usage for %s.\n", a->name);
820         use = kmalloc(sizeof(*use), GFP_ATOMIC);
821         if (!use) {
822                 pr_warn("%s: out of memory loading\n", a->name);
823                 return -ENOMEM;
824         }
825 
826         use->source = a;
827         use->target = b;
828         list_add(&use->source_list, &b->source_list);
829         list_add(&use->target_list, &a->target_list);
830         return 0;
831 }
832 
833 /* Module a uses b: caller needs module_mutex() */
834 int ref_module(struct module *a, struct module *b)
835 {
836         int err;
837 
838         if (b == NULL || already_uses(a, b))
839                 return 0;
840 
841         /* If module isn't available, we fail. */
842         err = strong_try_module_get(b);
843         if (err)
844                 return err;
845 
846         err = add_module_usage(a, b);
847         if (err) {
848                 module_put(b);
849                 return err;
850         }
851         return 0;
852 }
853 EXPORT_SYMBOL_GPL(ref_module);
854 
855 /* Clear the unload stuff of the module. */
856 static void module_unload_free(struct module *mod)
857 {
858         struct module_use *use, *tmp;
859 
860         mutex_lock(&module_mutex);
861         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
862                 struct module *i = use->target;
863                 pr_debug("%s unusing %s\n", mod->name, i->name);
864                 module_put(i);
865                 list_del(&use->source_list);
866                 list_del(&use->target_list);
867                 kfree(use);
868         }
869         mutex_unlock(&module_mutex);
870 }
871 
872 #ifdef CONFIG_MODULE_FORCE_UNLOAD
873 static inline int try_force_unload(unsigned int flags)
874 {
875         int ret = (flags & O_TRUNC);
876         if (ret)
877                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
878         return ret;
879 }
880 #else
881 static inline int try_force_unload(unsigned int flags)
882 {
883         return 0;
884 }
885 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
886 
887 /* Try to release refcount of module, 0 means success. */
888 static int try_release_module_ref(struct module *mod)
889 {
890         int ret;
891 
892         /* Try to decrement refcnt which we set at loading */
893         ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
894         BUG_ON(ret < 0);
895         if (ret)
896                 /* Someone can put this right now, recover with checking */
897                 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
898 
899         return ret;
900 }
901 
902 static int try_stop_module(struct module *mod, int flags, int *forced)
903 {
904         /* If it's not unused, quit unless we're forcing. */
905         if (try_release_module_ref(mod) != 0) {
906                 *forced = try_force_unload(flags);
907                 if (!(*forced))
908                         return -EWOULDBLOCK;
909         }
910 
911         /* Mark it as dying. */
912         mod->state = MODULE_STATE_GOING;
913 
914         return 0;
915 }
916 
917 /**
918  * module_refcount - return the refcount or -1 if unloading
919  *
920  * @mod:        the module we're checking
921  *
922  * Returns:
923  *      -1 if the module is in the process of unloading
924  *      otherwise the number of references in the kernel to the module
925  */
926 int module_refcount(struct module *mod)
927 {
928         return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
929 }
930 EXPORT_SYMBOL(module_refcount);
931 
932 /* This exists whether we can unload or not */
933 static void free_module(struct module *mod);
934 
935 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
936                 unsigned int, flags)
937 {
938         struct module *mod;
939         char name[MODULE_NAME_LEN];
940         int ret, forced = 0;
941 
942         if (!capable(CAP_SYS_MODULE) || modules_disabled)
943                 return -EPERM;
944         if (!ccs_capable(CCS_USE_KERNEL_MODULE))
945                 return -EPERM;
946 
947         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
948                 return -EFAULT;
949         name[MODULE_NAME_LEN-1] = '\0';
950 
951         if (mutex_lock_interruptible(&module_mutex) != 0)
952                 return -EINTR;
953 
954         mod = find_module(name);
955         if (!mod) {
956                 ret = -ENOENT;
957                 goto out;
958         }
959 
960         if (!list_empty(&mod->source_list)) {
961                 /* Other modules depend on us: get rid of them first. */
962                 ret = -EWOULDBLOCK;
963                 goto out;
964         }
965 
966         /* Doing init or already dying? */
967         if (mod->state != MODULE_STATE_LIVE) {
968                 /* FIXME: if (force), slam module count damn the torpedoes */
969                 pr_debug("%s already dying\n", mod->name);
970                 ret = -EBUSY;
971                 goto out;
972         }
973 
974         /* If it has an init func, it must have an exit func to unload */
975         if (mod->init && !mod->exit) {
976                 forced = try_force_unload(flags);
977                 if (!forced) {
978                         /* This module can't be removed */
979                         ret = -EBUSY;
980                         goto out;
981                 }
982         }
983 
984         /* Stop the machine so refcounts can't move and disable module. */
985         ret = try_stop_module(mod, flags, &forced);
986         if (ret != 0)
987                 goto out;
988 
989         mutex_unlock(&module_mutex);
990         /* Final destruction now no one is using it. */
991         if (mod->exit != NULL)
992                 mod->exit();
993         blocking_notifier_call_chain(&module_notify_list,
994                                      MODULE_STATE_GOING, mod);
995         klp_module_going(mod);
996         ftrace_release_mod(mod);
997 
998         async_synchronize_full();
999 
1000         /* Store the name of the last unloaded module for diagnostic purposes */
1001         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1002 
1003         free_module(mod);
1004         return 0;
1005 out:
1006         mutex_unlock(&module_mutex);
1007         return ret;
1008 }
1009 
1010 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1011 {
1012         struct module_use *use;
1013         int printed_something = 0;
1014 
1015         seq_printf(m, " %i ", module_refcount(mod));
1016 
1017         /*
1018          * Always include a trailing , so userspace can differentiate
1019          * between this and the old multi-field proc format.
1020          */
1021         list_for_each_entry(use, &mod->source_list, source_list) {
1022                 printed_something = 1;
1023                 seq_printf(m, "%s,", use->source->name);
1024         }
1025 
1026         if (mod->init != NULL && mod->exit == NULL) {
1027                 printed_something = 1;
1028                 seq_puts(m, "[permanent],");
1029         }
1030 
1031         if (!printed_something)
1032                 seq_puts(m, "-");
1033 }
1034 
1035 void __symbol_put(const char *symbol)
1036 {
1037         struct module *owner;
1038 
1039         preempt_disable();
1040         if (!find_symbol(symbol, &owner, NULL, true, false))
1041                 BUG();
1042         module_put(owner);
1043         preempt_enable();
1044 }
1045 EXPORT_SYMBOL(__symbol_put);
1046 
1047 /* Note this assumes addr is a function, which it currently always is. */
1048 void symbol_put_addr(void *addr)
1049 {
1050         struct module *modaddr;
1051         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1052 
1053         if (core_kernel_text(a))
1054                 return;
1055 
1056         /*
1057          * Even though we hold a reference on the module; we still need to
1058          * disable preemption in order to safely traverse the data structure.
1059          */
1060         preempt_disable();
1061         modaddr = __module_text_address(a);
1062         BUG_ON(!modaddr);
1063         module_put(modaddr);
1064         preempt_enable();
1065 }
1066 EXPORT_SYMBOL_GPL(symbol_put_addr);
1067 
1068 static ssize_t show_refcnt(struct module_attribute *mattr,
1069                            struct module_kobject *mk, char *buffer)
1070 {
1071         return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1072 }
1073 
1074 static struct module_attribute modinfo_refcnt =
1075         __ATTR(refcnt, 0444, show_refcnt, NULL);
1076 
1077 void __module_get(struct module *module)
1078 {
1079         if (module) {
1080                 preempt_disable();
1081                 atomic_inc(&module->refcnt);
1082                 trace_module_get(module, _RET_IP_);
1083                 preempt_enable();
1084         }
1085 }
1086 EXPORT_SYMBOL(__module_get);
1087 
1088 bool try_module_get(struct module *module)
1089 {
1090         bool ret = true;
1091 
1092         if (module) {
1093                 preempt_disable();
1094                 /* Note: here, we can fail to get a reference */
1095                 if (likely(module_is_live(module) &&
1096                            atomic_inc_not_zero(&module->refcnt) != 0))
1097                         trace_module_get(module, _RET_IP_);
1098                 else
1099                         ret = false;
1100 
1101                 preempt_enable();
1102         }
1103         return ret;
1104 }
1105 EXPORT_SYMBOL(try_module_get);
1106 
1107 void module_put(struct module *module)
1108 {
1109         int ret;
1110 
1111         if (module) {
1112                 preempt_disable();
1113                 ret = atomic_dec_if_positive(&module->refcnt);
1114                 WARN_ON(ret < 0);       /* Failed to put refcount */
1115                 trace_module_put(module, _RET_IP_);
1116                 preempt_enable();
1117         }
1118 }
1119 EXPORT_SYMBOL(module_put);
1120 
1121 #else /* !CONFIG_MODULE_UNLOAD */
1122 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1123 {
1124         /* We don't know the usage count, or what modules are using. */
1125         seq_puts(m, " - -");
1126 }
1127 
1128 static inline void module_unload_free(struct module *mod)
1129 {
1130 }
1131 
1132 int ref_module(struct module *a, struct module *b)
1133 {
1134         return strong_try_module_get(b);
1135 }
1136 EXPORT_SYMBOL_GPL(ref_module);
1137 
1138 static inline int module_unload_init(struct module *mod)
1139 {
1140         return 0;
1141 }
1142 #endif /* CONFIG_MODULE_UNLOAD */
1143 
1144 static size_t module_flags_taint(struct module *mod, char *buf)
1145 {
1146         size_t l = 0;
1147         int i;
1148 
1149         for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1150                 if (taint_flags[i].module && test_bit(i, &mod->taints))
1151                         buf[l++] = taint_flags[i].c_true;
1152         }
1153 
1154         return l;
1155 }
1156 
1157 static ssize_t show_initstate(struct module_attribute *mattr,
1158                               struct module_kobject *mk, char *buffer)
1159 {
1160         const char *state = "unknown";
1161 
1162         switch (mk->mod->state) {
1163         case MODULE_STATE_LIVE:
1164                 state = "live";
1165                 break;
1166         case MODULE_STATE_COMING:
1167                 state = "coming";
1168                 break;
1169         case MODULE_STATE_GOING:
1170                 state = "going";
1171                 break;
1172         default:
1173                 BUG();
1174         }
1175         return sprintf(buffer, "%s\n", state);
1176 }
1177 
1178 static struct module_attribute modinfo_initstate =
1179         __ATTR(initstate, 0444, show_initstate, NULL);
1180 
1181 static ssize_t store_uevent(struct module_attribute *mattr,
1182                             struct module_kobject *mk,
1183                             const char *buffer, size_t count)
1184 {
1185         enum kobject_action action;
1186 
1187         if (kobject_action_type(buffer, count, &action) == 0)
1188                 kobject_uevent(&mk->kobj, action);
1189         return count;
1190 }
1191 
1192 struct module_attribute module_uevent =
1193         __ATTR(uevent, 0200, NULL, store_uevent);
1194 
1195 static ssize_t show_coresize(struct module_attribute *mattr,
1196                              struct module_kobject *mk, char *buffer)
1197 {
1198         return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1199 }
1200 
1201 static struct module_attribute modinfo_coresize =
1202         __ATTR(coresize, 0444, show_coresize, NULL);
1203 
1204 static ssize_t show_initsize(struct module_attribute *mattr,
1205                              struct module_kobject *mk, char *buffer)
1206 {
1207         return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1208 }
1209 
1210 static struct module_attribute modinfo_initsize =
1211         __ATTR(initsize, 0444, show_initsize, NULL);
1212 
1213 static ssize_t show_taint(struct module_attribute *mattr,
1214                           struct module_kobject *mk, char *buffer)
1215 {
1216         size_t l;
1217 
1218         l = module_flags_taint(mk->mod, buffer);
1219         buffer[l++] = '\n';
1220         return l;
1221 }
1222 
1223 static struct module_attribute modinfo_taint =
1224         __ATTR(taint, 0444, show_taint, NULL);
1225 
1226 static struct module_attribute *modinfo_attrs[] = {
1227         &module_uevent,
1228         &modinfo_version,
1229         &modinfo_srcversion,
1230         &modinfo_initstate,
1231         &modinfo_coresize,
1232         &modinfo_initsize,
1233         &modinfo_taint,
1234 #ifdef CONFIG_MODULE_UNLOAD
1235         &modinfo_refcnt,
1236 #endif
1237         NULL,
1238 };
1239 
1240 static const char vermagic[] = VERMAGIC_STRING;
1241 
1242 static int try_to_force_load(struct module *mod, const char *reason)
1243 {
1244 #ifdef CONFIG_MODULE_FORCE_LOAD
1245         if (!test_taint(TAINT_FORCED_MODULE))
1246                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1247         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1248         return 0;
1249 #else
1250         return -ENOEXEC;
1251 #endif
1252 }
1253 
1254 #ifdef CONFIG_MODVERSIONS
1255 
1256 static u32 resolve_rel_crc(const s32 *crc)
1257 {
1258         return *(u32 *)((void *)crc + *crc);
1259 }
1260 
1261 static int check_version(Elf_Shdr *sechdrs,
1262                          unsigned int versindex,
1263                          const char *symname,
1264                          struct module *mod,
1265                          const s32 *crc)
1266 {
1267         unsigned int i, num_versions;
1268         struct modversion_info *versions;
1269 
1270         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1271         if (!crc)
1272                 return 1;
1273 
1274         /* No versions at all?  modprobe --force does this. */
1275         if (versindex == 0)
1276                 return try_to_force_load(mod, symname) == 0;
1277 
1278         versions = (void *) sechdrs[versindex].sh_addr;
1279         num_versions = sechdrs[versindex].sh_size
1280                 / sizeof(struct modversion_info);
1281 
1282         for (i = 0; i < num_versions; i++) {
1283                 u32 crcval;
1284 
1285                 if (strcmp(versions[i].name, symname) != 0)
1286                         continue;
1287 
1288                 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1289                         crcval = resolve_rel_crc(crc);
1290                 else
1291                         crcval = *crc;
1292                 if (versions[i].crc == crcval)
1293                         return 1;
1294                 pr_debug("Found checksum %X vs module %lX\n",
1295                          crcval, versions[i].crc);
1296                 goto bad_version;
1297         }
1298 
1299         /* Broken toolchain. Warn once, then let it go.. */
1300         pr_warn_once("%s: no symbol version for %s\n", mod->name, symname);
1301         return 1;
1302 
1303 bad_version:
1304         pr_warn("%s: disagrees about version of symbol %s\n",
1305                mod->name, symname);
1306         return 0;
1307 }
1308 
1309 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1310                                           unsigned int versindex,
1311                                           struct module *mod)
1312 {
1313         const s32 *crc;
1314 
1315         /*
1316          * Since this should be found in kernel (which can't be removed), no
1317          * locking is necessary -- use preempt_disable() to placate lockdep.
1318          */
1319         preempt_disable();
1320         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1321                          &crc, true, false)) {
1322                 preempt_enable();
1323                 BUG();
1324         }
1325         preempt_enable();
1326         return check_version(sechdrs, versindex,
1327                              VMLINUX_SYMBOL_STR(module_layout), mod, crc);
1328 }
1329 
1330 /* First part is kernel version, which we ignore if module has crcs. */
1331 static inline int same_magic(const char *amagic, const char *bmagic,
1332                              bool has_crcs)
1333 {
1334         if (has_crcs) {
1335                 amagic += strcspn(amagic, " ");
1336                 bmagic += strcspn(bmagic, " ");
1337         }
1338         return strcmp(amagic, bmagic) == 0;
1339 }
1340 #else
1341 static inline int check_version(Elf_Shdr *sechdrs,
1342                                 unsigned int versindex,
1343                                 const char *symname,
1344                                 struct module *mod,
1345                                 const s32 *crc)
1346 {
1347         return 1;
1348 }
1349 
1350 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1351                                           unsigned int versindex,
1352                                           struct module *mod)
1353 {
1354         return 1;
1355 }
1356 
1357 static inline int same_magic(const char *amagic, const char *bmagic,
1358                              bool has_crcs)
1359 {
1360         return strcmp(amagic, bmagic) == 0;
1361 }
1362 #endif /* CONFIG_MODVERSIONS */
1363 
1364 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1365 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1366                                                   const struct load_info *info,
1367                                                   const char *name,
1368                                                   char ownername[])
1369 {
1370         struct module *owner;
1371         const struct kernel_symbol *sym;
1372         const s32 *crc;
1373         int err;
1374 
1375         /*
1376          * The module_mutex should not be a heavily contended lock;
1377          * if we get the occasional sleep here, we'll go an extra iteration
1378          * in the wait_event_interruptible(), which is harmless.
1379          */
1380         sched_annotate_sleep();
1381         mutex_lock(&module_mutex);
1382         sym = find_symbol(name, &owner, &crc,
1383                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1384         if (!sym)
1385                 goto unlock;
1386 
1387         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc)) {
1388                 sym = ERR_PTR(-EINVAL);
1389                 goto getname;
1390         }
1391 
1392         err = ref_module(mod, owner);
1393         if (err) {
1394                 sym = ERR_PTR(err);
1395                 goto getname;
1396         }
1397 
1398 getname:
1399         /* We must make copy under the lock if we failed to get ref. */
1400         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1401 unlock:
1402         mutex_unlock(&module_mutex);
1403         return sym;
1404 }
1405 
1406 static const struct kernel_symbol *
1407 resolve_symbol_wait(struct module *mod,
1408                     const struct load_info *info,
1409                     const char *name)
1410 {
1411         const struct kernel_symbol *ksym;
1412         char owner[MODULE_NAME_LEN];
1413 
1414         if (wait_event_interruptible_timeout(module_wq,
1415                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1416                         || PTR_ERR(ksym) != -EBUSY,
1417                                              30 * HZ) <= 0) {
1418                 pr_warn("%s: gave up waiting for init of module %s.\n",
1419                         mod->name, owner);
1420         }
1421         return ksym;
1422 }
1423 
1424 /*
1425  * /sys/module/foo/sections stuff
1426  * J. Corbet <corbet@lwn.net>
1427  */
1428 #ifdef CONFIG_SYSFS
1429 
1430 #ifdef CONFIG_KALLSYMS
1431 static inline bool sect_empty(const Elf_Shdr *sect)
1432 {
1433         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1434 }
1435 
1436 struct module_sect_attr {
1437         struct module_attribute mattr;
1438         char *name;
1439         unsigned long address;
1440 };
1441 
1442 struct module_sect_attrs {
1443         struct attribute_group grp;
1444         unsigned int nsections;
1445         struct module_sect_attr attrs[0];
1446 };
1447 
1448 static ssize_t module_sect_show(struct module_attribute *mattr,
1449                                 struct module_kobject *mk, char *buf)
1450 {
1451         struct module_sect_attr *sattr =
1452                 container_of(mattr, struct module_sect_attr, mattr);
1453         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1454 }
1455 
1456 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1457 {
1458         unsigned int section;
1459 
1460         for (section = 0; section < sect_attrs->nsections; section++)
1461                 kfree(sect_attrs->attrs[section].name);
1462         kfree(sect_attrs);
1463 }
1464 
1465 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1466 {
1467         unsigned int nloaded = 0, i, size[2];
1468         struct module_sect_attrs *sect_attrs;
1469         struct module_sect_attr *sattr;
1470         struct attribute **gattr;
1471 
1472         /* Count loaded sections and allocate structures */
1473         for (i = 0; i < info->hdr->e_shnum; i++)
1474                 if (!sect_empty(&info->sechdrs[i]))
1475                         nloaded++;
1476         size[0] = ALIGN(sizeof(*sect_attrs)
1477                         + nloaded * sizeof(sect_attrs->attrs[0]),
1478                         sizeof(sect_attrs->grp.attrs[0]));
1479         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1480         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1481         if (sect_attrs == NULL)
1482                 return;
1483 
1484         /* Setup section attributes. */
1485         sect_attrs->grp.name = "sections";
1486         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1487 
1488         sect_attrs->nsections = 0;
1489         sattr = &sect_attrs->attrs[0];
1490         gattr = &sect_attrs->grp.attrs[0];
1491         for (i = 0; i < info->hdr->e_shnum; i++) {
1492                 Elf_Shdr *sec = &info->sechdrs[i];
1493                 if (sect_empty(sec))
1494                         continue;
1495                 sattr->address = sec->sh_addr;
1496                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1497                                         GFP_KERNEL);
1498                 if (sattr->name == NULL)
1499                         goto out;
1500                 sect_attrs->nsections++;
1501                 sysfs_attr_init(&sattr->mattr.attr);
1502                 sattr->mattr.show = module_sect_show;
1503                 sattr->mattr.store = NULL;
1504                 sattr->mattr.attr.name = sattr->name;
1505                 sattr->mattr.attr.mode = S_IRUGO;
1506                 *(gattr++) = &(sattr++)->mattr.attr;
1507         }
1508         *gattr = NULL;
1509 
1510         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1511                 goto out;
1512 
1513         mod->sect_attrs = sect_attrs;
1514         return;
1515   out:
1516         free_sect_attrs(sect_attrs);
1517 }
1518 
1519 static void remove_sect_attrs(struct module *mod)
1520 {
1521         if (mod->sect_attrs) {
1522                 sysfs_remove_group(&mod->mkobj.kobj,
1523                                    &mod->sect_attrs->grp);
1524                 /* We are positive that no one is using any sect attrs
1525                  * at this point.  Deallocate immediately. */
1526                 free_sect_attrs(mod->sect_attrs);
1527                 mod->sect_attrs = NULL;
1528         }
1529 }
1530 
1531 /*
1532  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1533  */
1534 
1535 struct module_notes_attrs {
1536         struct kobject *dir;
1537         unsigned int notes;
1538         struct bin_attribute attrs[0];
1539 };
1540 
1541 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1542                                  struct bin_attribute *bin_attr,
1543                                  char *buf, loff_t pos, size_t count)
1544 {
1545         /*
1546          * The caller checked the pos and count against our size.
1547          */
1548         memcpy(buf, bin_attr->private + pos, count);
1549         return count;
1550 }
1551 
1552 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1553                              unsigned int i)
1554 {
1555         if (notes_attrs->dir) {
1556                 while (i-- > 0)
1557                         sysfs_remove_bin_file(notes_attrs->dir,
1558                                               &notes_attrs->attrs[i]);
1559                 kobject_put(notes_attrs->dir);
1560         }
1561         kfree(notes_attrs);
1562 }
1563 
1564 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1565 {
1566         unsigned int notes, loaded, i;
1567         struct module_notes_attrs *notes_attrs;
1568         struct bin_attribute *nattr;
1569 
1570         /* failed to create section attributes, so can't create notes */
1571         if (!mod->sect_attrs)
1572                 return;
1573 
1574         /* Count notes sections and allocate structures.  */
1575         notes = 0;
1576         for (i = 0; i < info->hdr->e_shnum; i++)
1577                 if (!sect_empty(&info->sechdrs[i]) &&
1578                     (info->sechdrs[i].sh_type == SHT_NOTE))
1579                         ++notes;
1580 
1581         if (notes == 0)
1582                 return;
1583 
1584         notes_attrs = kzalloc(sizeof(*notes_attrs)
1585                               + notes * sizeof(notes_attrs->attrs[0]),
1586                               GFP_KERNEL);
1587         if (notes_attrs == NULL)
1588                 return;
1589 
1590         notes_attrs->notes = notes;
1591         nattr = &notes_attrs->attrs[0];
1592         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1593                 if (sect_empty(&info->sechdrs[i]))
1594                         continue;
1595                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1596                         sysfs_bin_attr_init(nattr);
1597                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1598                         nattr->attr.mode = S_IRUGO;
1599                         nattr->size = info->sechdrs[i].sh_size;
1600                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1601                         nattr->read = module_notes_read;
1602                         ++nattr;
1603                 }
1604                 ++loaded;
1605         }
1606 
1607         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1608         if (!notes_attrs->dir)
1609                 goto out;
1610 
1611         for (i = 0; i < notes; ++i)
1612                 if (sysfs_create_bin_file(notes_attrs->dir,
1613                                           &notes_attrs->attrs[i]))
1614                         goto out;
1615 
1616         mod->notes_attrs = notes_attrs;
1617         return;
1618 
1619   out:
1620         free_notes_attrs(notes_attrs, i);
1621 }
1622 
1623 static void remove_notes_attrs(struct module *mod)
1624 {
1625         if (mod->notes_attrs)
1626                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1627 }
1628 
1629 #else
1630 
1631 static inline void add_sect_attrs(struct module *mod,
1632                                   const struct load_info *info)
1633 {
1634 }
1635 
1636 static inline void remove_sect_attrs(struct module *mod)
1637 {
1638 }
1639 
1640 static inline void add_notes_attrs(struct module *mod,
1641                                    const struct load_info *info)
1642 {
1643 }
1644 
1645 static inline void remove_notes_attrs(struct module *mod)
1646 {
1647 }
1648 #endif /* CONFIG_KALLSYMS */
1649 
1650 static void add_usage_links(struct module *mod)
1651 {
1652 #ifdef CONFIG_MODULE_UNLOAD
1653         struct module_use *use;
1654         int nowarn;
1655 
1656         mutex_lock(&module_mutex);
1657         list_for_each_entry(use, &mod->target_list, target_list) {
1658                 nowarn = sysfs_create_link(use->target->holders_dir,
1659                                            &mod->mkobj.kobj, mod->name);
1660         }
1661         mutex_unlock(&module_mutex);
1662 #endif
1663 }
1664 
1665 static void del_usage_links(struct module *mod)
1666 {
1667 #ifdef CONFIG_MODULE_UNLOAD
1668         struct module_use *use;
1669 
1670         mutex_lock(&module_mutex);
1671         list_for_each_entry(use, &mod->target_list, target_list)
1672                 sysfs_remove_link(use->target->holders_dir, mod->name);
1673         mutex_unlock(&module_mutex);
1674 #endif
1675 }
1676 
1677 static int module_add_modinfo_attrs(struct module *mod)
1678 {
1679         struct module_attribute *attr;
1680         struct module_attribute *temp_attr;
1681         int error = 0;
1682         int i;
1683 
1684         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1685                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1686                                         GFP_KERNEL);
1687         if (!mod->modinfo_attrs)
1688                 return -ENOMEM;
1689 
1690         temp_attr = mod->modinfo_attrs;
1691         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1692                 if (!attr->test || attr->test(mod)) {
1693                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1694                         sysfs_attr_init(&temp_attr->attr);
1695                         error = sysfs_create_file(&mod->mkobj.kobj,
1696                                         &temp_attr->attr);
1697                         ++temp_attr;
1698                 }
1699         }
1700         return error;
1701 }
1702 
1703 static void module_remove_modinfo_attrs(struct module *mod)
1704 {
1705         struct module_attribute *attr;
1706         int i;
1707 
1708         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1709                 /* pick a field to test for end of list */
1710                 if (!attr->attr.name)
1711                         break;
1712                 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1713                 if (attr->free)
1714                         attr->free(mod);
1715         }
1716         kfree(mod->modinfo_attrs);
1717 }
1718 
1719 static void mod_kobject_put(struct module *mod)
1720 {
1721         DECLARE_COMPLETION_ONSTACK(c);
1722         mod->mkobj.kobj_completion = &c;
1723         kobject_put(&mod->mkobj.kobj);
1724         wait_for_completion(&c);
1725 }
1726 
1727 static int mod_sysfs_init(struct module *mod)
1728 {
1729         int err;
1730         struct kobject *kobj;
1731 
1732         if (!module_sysfs_initialized) {
1733                 pr_err("%s: module sysfs not initialized\n", mod->name);
1734                 err = -EINVAL;
1735                 goto out;
1736         }
1737 
1738         kobj = kset_find_obj(module_kset, mod->name);
1739         if (kobj) {
1740                 pr_err("%s: module is already loaded\n", mod->name);
1741                 kobject_put(kobj);
1742                 err = -EINVAL;
1743                 goto out;
1744         }
1745 
1746         mod->mkobj.mod = mod;
1747 
1748         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1749         mod->mkobj.kobj.kset = module_kset;
1750         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1751                                    "%s", mod->name);
1752         if (err)
1753                 mod_kobject_put(mod);
1754 
1755         /* delay uevent until full sysfs population */
1756 out:
1757         return err;
1758 }
1759 
1760 static int mod_sysfs_setup(struct module *mod,
1761                            const struct load_info *info,
1762                            struct kernel_param *kparam,
1763                            unsigned int num_params)
1764 {
1765         int err;
1766 
1767         err = mod_sysfs_init(mod);
1768         if (err)
1769                 goto out;
1770 
1771         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1772         if (!mod->holders_dir) {
1773                 err = -ENOMEM;
1774                 goto out_unreg;
1775         }
1776 
1777         err = module_param_sysfs_setup(mod, kparam, num_params);
1778         if (err)
1779                 goto out_unreg_holders;
1780 
1781         err = module_add_modinfo_attrs(mod);
1782         if (err)
1783                 goto out_unreg_param;
1784 
1785         add_usage_links(mod);
1786         add_sect_attrs(mod, info);
1787         add_notes_attrs(mod, info);
1788 
1789         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1790         return 0;
1791 
1792 out_unreg_param:
1793         module_param_sysfs_remove(mod);
1794 out_unreg_holders:
1795         kobject_put(mod->holders_dir);
1796 out_unreg:
1797         mod_kobject_put(mod);
1798 out:
1799         return err;
1800 }
1801 
1802 static void mod_sysfs_fini(struct module *mod)
1803 {
1804         remove_notes_attrs(mod);
1805         remove_sect_attrs(mod);
1806         mod_kobject_put(mod);
1807 }
1808 
1809 static void init_param_lock(struct module *mod)
1810 {
1811         mutex_init(&mod->param_lock);
1812 }
1813 #else /* !CONFIG_SYSFS */
1814 
1815 static int mod_sysfs_setup(struct module *mod,
1816                            const struct load_info *info,
1817                            struct kernel_param *kparam,
1818                            unsigned int num_params)
1819 {
1820         return 0;
1821 }
1822 
1823 static void mod_sysfs_fini(struct module *mod)
1824 {
1825 }
1826 
1827 static void module_remove_modinfo_attrs(struct module *mod)
1828 {
1829 }
1830 
1831 static void del_usage_links(struct module *mod)
1832 {
1833 }
1834 
1835 static void init_param_lock(struct module *mod)
1836 {
1837 }
1838 #endif /* CONFIG_SYSFS */
1839 
1840 static void mod_sysfs_teardown(struct module *mod)
1841 {
1842         del_usage_links(mod);
1843         module_remove_modinfo_attrs(mod);
1844         module_param_sysfs_remove(mod);
1845         kobject_put(mod->mkobj.drivers_dir);
1846         kobject_put(mod->holders_dir);
1847         mod_sysfs_fini(mod);
1848 }
1849 
1850 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1851 /*
1852  * LKM RO/NX protection: protect module's text/ro-data
1853  * from modification and any data from execution.
1854  *
1855  * General layout of module is:
1856  *          [text] [read-only-data] [ro-after-init] [writable data]
1857  * text_size -----^                ^               ^               ^
1858  * ro_size ------------------------|               |               |
1859  * ro_after_init_size -----------------------------|               |
1860  * size -----------------------------------------------------------|
1861  *
1862  * These values are always page-aligned (as is base)
1863  */
1864 static void frob_text(const struct module_layout *layout,
1865                       int (*set_memory)(unsigned long start, int num_pages))
1866 {
1867         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1868         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1869         set_memory((unsigned long)layout->base,
1870                    layout->text_size >> PAGE_SHIFT);
1871 }
1872 
1873 static void frob_rodata(const struct module_layout *layout,
1874                         int (*set_memory)(unsigned long start, int num_pages))
1875 {
1876         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1877         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1878         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1879         set_memory((unsigned long)layout->base + layout->text_size,
1880                    (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1881 }
1882 
1883 static void frob_ro_after_init(const struct module_layout *layout,
1884                                 int (*set_memory)(unsigned long start, int num_pages))
1885 {
1886         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1887         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1888         BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1889         set_memory((unsigned long)layout->base + layout->ro_size,
1890                    (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1891 }
1892 
1893 static void frob_writable_data(const struct module_layout *layout,
1894                                int (*set_memory)(unsigned long start, int num_pages))
1895 {
1896         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1897         BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1898         BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1899         set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1900                    (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1901 }
1902 
1903 /* livepatching wants to disable read-only so it can frob module. */
1904 void module_disable_ro(const struct module *mod)
1905 {
1906         if (!rodata_enabled)
1907                 return;
1908 
1909         frob_text(&mod->core_layout, set_memory_rw);
1910         frob_rodata(&mod->core_layout, set_memory_rw);
1911         frob_ro_after_init(&mod->core_layout, set_memory_rw);
1912         frob_text(&mod->init_layout, set_memory_rw);
1913         frob_rodata(&mod->init_layout, set_memory_rw);
1914 }
1915 
1916 void module_enable_ro(const struct module *mod, bool after_init)
1917 {
1918         if (!rodata_enabled)
1919                 return;
1920 
1921         frob_text(&mod->core_layout, set_memory_ro);
1922         frob_rodata(&mod->core_layout, set_memory_ro);
1923         frob_text(&mod->init_layout, set_memory_ro);
1924         frob_rodata(&mod->init_layout, set_memory_ro);
1925 
1926         if (after_init)
1927                 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1928 }
1929 
1930 static void module_enable_nx(const struct module *mod)
1931 {
1932         frob_rodata(&mod->core_layout, set_memory_nx);
1933         frob_ro_after_init(&mod->core_layout, set_memory_nx);
1934         frob_writable_data(&mod->core_layout, set_memory_nx);
1935         frob_rodata(&mod->init_layout, set_memory_nx);
1936         frob_writable_data(&mod->init_layout, set_memory_nx);
1937 }
1938 
1939 static void module_disable_nx(const struct module *mod)
1940 {
1941         frob_rodata(&mod->core_layout, set_memory_x);
1942         frob_ro_after_init(&mod->core_layout, set_memory_x);
1943         frob_writable_data(&mod->core_layout, set_memory_x);
1944         frob_rodata(&mod->init_layout, set_memory_x);
1945         frob_writable_data(&mod->init_layout, set_memory_x);
1946 }
1947 
1948 /* Iterate through all modules and set each module's text as RW */
1949 void set_all_modules_text_rw(void)
1950 {
1951         struct module *mod;
1952 
1953         if (!rodata_enabled)
1954                 return;
1955 
1956         mutex_lock(&module_mutex);
1957         list_for_each_entry_rcu(mod, &modules, list) {
1958                 if (mod->state == MODULE_STATE_UNFORMED)
1959                         continue;
1960 
1961                 frob_text(&mod->core_layout, set_memory_rw);
1962                 frob_text(&mod->init_layout, set_memory_rw);
1963         }
1964         mutex_unlock(&module_mutex);
1965 }
1966 
1967 /* Iterate through all modules and set each module's text as RO */
1968 void set_all_modules_text_ro(void)
1969 {
1970         struct module *mod;
1971 
1972         if (!rodata_enabled)
1973                 return;
1974 
1975         mutex_lock(&module_mutex);
1976         list_for_each_entry_rcu(mod, &modules, list) {
1977                 /*
1978                  * Ignore going modules since it's possible that ro
1979                  * protection has already been disabled, otherwise we'll
1980                  * run into protection faults at module deallocation.
1981                  */
1982                 if (mod->state == MODULE_STATE_UNFORMED ||
1983                         mod->state == MODULE_STATE_GOING)
1984                         continue;
1985 
1986                 frob_text(&mod->core_layout, set_memory_ro);
1987                 frob_text(&mod->init_layout, set_memory_ro);
1988         }
1989         mutex_unlock(&module_mutex);
1990 }
1991 
1992 static void disable_ro_nx(const struct module_layout *layout)
1993 {
1994         if (rodata_enabled) {
1995                 frob_text(layout, set_memory_rw);
1996                 frob_rodata(layout, set_memory_rw);
1997                 frob_ro_after_init(layout, set_memory_rw);
1998         }
1999         frob_rodata(layout, set_memory_x);
2000         frob_ro_after_init(layout, set_memory_x);
2001         frob_writable_data(layout, set_memory_x);
2002 }
2003 
2004 #else
2005 static void disable_ro_nx(const struct module_layout *layout) { }
2006 static void module_enable_nx(const struct module *mod) { }
2007 static void module_disable_nx(const struct module *mod) { }
2008 #endif
2009 
2010 #ifdef CONFIG_LIVEPATCH
2011 /*
2012  * Persist Elf information about a module. Copy the Elf header,
2013  * section header table, section string table, and symtab section
2014  * index from info to mod->klp_info.
2015  */
2016 static int copy_module_elf(struct module *mod, struct load_info *info)
2017 {
2018         unsigned int size, symndx;
2019         int ret;
2020 
2021         size = sizeof(*mod->klp_info);
2022         mod->klp_info = kmalloc(size, GFP_KERNEL);
2023         if (mod->klp_info == NULL)
2024                 return -ENOMEM;
2025 
2026         /* Elf header */
2027         size = sizeof(mod->klp_info->hdr);
2028         memcpy(&mod->klp_info->hdr, info->hdr, size);
2029 
2030         /* Elf section header table */
2031         size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2032         mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
2033         if (mod->klp_info->sechdrs == NULL) {
2034                 ret = -ENOMEM;
2035                 goto free_info;
2036         }
2037         memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2038 
2039         /* Elf section name string table */
2040         size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2041         mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2042         if (mod->klp_info->secstrings == NULL) {
2043                 ret = -ENOMEM;
2044                 goto free_sechdrs;
2045         }
2046         memcpy(mod->klp_info->secstrings, info->secstrings, size);
2047 
2048         /* Elf symbol section index */
2049         symndx = info->index.sym;
2050         mod->klp_info->symndx = symndx;
2051 
2052         /*
2053          * For livepatch modules, core_kallsyms.symtab is a complete
2054          * copy of the original symbol table. Adjust sh_addr to point
2055          * to core_kallsyms.symtab since the copy of the symtab in module
2056          * init memory is freed at the end of do_init_module().
2057          */
2058         mod->klp_info->sechdrs[symndx].sh_addr = \
2059                 (unsigned long) mod->core_kallsyms.symtab;
2060 
2061         return 0;
2062 
2063 free_sechdrs:
2064         kfree(mod->klp_info->sechdrs);
2065 free_info:
2066         kfree(mod->klp_info);
2067         return ret;
2068 }
2069 
2070 static void free_module_elf(struct module *mod)
2071 {
2072         kfree(mod->klp_info->sechdrs);
2073         kfree(mod->klp_info->secstrings);
2074         kfree(mod->klp_info);
2075 }
2076 #else /* !CONFIG_LIVEPATCH */
2077 static int copy_module_elf(struct module *mod, struct load_info *info)
2078 {
2079         return 0;
2080 }
2081 
2082 static void free_module_elf(struct module *mod)
2083 {
2084 }
2085 #endif /* CONFIG_LIVEPATCH */
2086 
2087 void __weak module_memfree(void *module_region)
2088 {
2089         vfree(module_region);
2090 }
2091 
2092 void __weak module_arch_cleanup(struct module *mod)
2093 {
2094 }
2095 
2096 void __weak module_arch_freeing_init(struct module *mod)
2097 {
2098 }
2099 
2100 /* Free a module, remove from lists, etc. */
2101 static void free_module(struct module *mod)
2102 {
2103         trace_module_free(mod);
2104 
2105         mod_sysfs_teardown(mod);
2106 
2107         /* We leave it in list to prevent duplicate loads, but make sure
2108          * that noone uses it while it's being deconstructed. */
2109         mutex_lock(&module_mutex);
2110         mod->state = MODULE_STATE_UNFORMED;
2111         mutex_unlock(&module_mutex);
2112 
2113         /* Remove dynamic debug info */
2114         ddebug_remove_module(mod->name);
2115 
2116         /* Arch-specific cleanup. */
2117         module_arch_cleanup(mod);
2118 
2119         /* Module unload stuff */
2120         module_unload_free(mod);
2121 
2122         /* Free any allocated parameters. */
2123         destroy_params(mod->kp, mod->num_kp);
2124 
2125         if (is_livepatch_module(mod))
2126                 free_module_elf(mod);
2127 
2128         /* Now we can delete it from the lists */
2129         mutex_lock(&module_mutex);
2130         /* Unlink carefully: kallsyms could be walking list. */
2131         list_del_rcu(&mod->list);
2132         mod_tree_remove(mod);
2133         /* Remove this module from bug list, this uses list_del_rcu */
2134         module_bug_cleanup(mod);
2135         /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2136         synchronize_sched();
2137         mutex_unlock(&module_mutex);
2138 
2139         /* This may be empty, but that's OK */
2140         disable_ro_nx(&mod->init_layout);
2141         module_arch_freeing_init(mod);
2142         module_memfree(mod->init_layout.base);
2143         kfree(mod->args);
2144         percpu_modfree(mod);
2145 
2146         /* Free lock-classes; relies on the preceding sync_rcu(). */
2147         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2148 
2149         /* Finally, free the core (containing the module structure) */
2150         disable_ro_nx(&mod->core_layout);
2151         module_memfree(mod->core_layout.base);
2152 
2153 #ifdef CONFIG_MPU
2154         update_protections(current->mm);
2155 #endif
2156 }
2157 
2158 void *__symbol_get(const char *symbol)
2159 {
2160         struct module *owner;
2161         const struct kernel_symbol *sym;
2162 
2163         preempt_disable();
2164         sym = find_symbol(symbol, &owner, NULL, true, true);
2165         if (sym && strong_try_module_get(owner))
2166                 sym = NULL;
2167         preempt_enable();
2168 
2169         return sym ? (void *)sym->value : NULL;
2170 }
2171 EXPORT_SYMBOL_GPL(__symbol_get);
2172 
2173 /*
2174  * Ensure that an exported symbol [global namespace] does not already exist
2175  * in the kernel or in some other module's exported symbol table.
2176  *
2177  * You must hold the module_mutex.
2178  */
2179 static int verify_export_symbols(struct module *mod)
2180 {
2181         unsigned int i;
2182         struct module *owner;
2183         const struct kernel_symbol *s;
2184         struct {
2185                 const struct kernel_symbol *sym;
2186                 unsigned int num;
2187         } arr[] = {
2188                 { mod->syms, mod->num_syms },
2189                 { mod->gpl_syms, mod->num_gpl_syms },
2190                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2191 #ifdef CONFIG_UNUSED_SYMBOLS
2192                 { mod->unused_syms, mod->num_unused_syms },
2193                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2194 #endif
2195         };
2196 
2197         for (i = 0; i < ARRAY_SIZE(arr); i++) {
2198                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2199                         if (find_symbol(s->name, &owner, NULL, true, false)) {
2200                                 pr_err("%s: exports duplicate symbol %s"
2201                                        " (owned by %s)\n",
2202                                        mod->name, s->name, module_name(owner));
2203                                 return -ENOEXEC;
2204                         }
2205                 }
2206         }
2207         return 0;
2208 }
2209 
2210 /* Change all symbols so that st_value encodes the pointer directly. */
2211 static int simplify_symbols(struct module *mod, const struct load_info *info)
2212 {
2213         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2214         Elf_Sym *sym = (void *)symsec->sh_addr;
2215         unsigned long secbase;
2216         unsigned int i;
2217         int ret = 0;
2218         const struct kernel_symbol *ksym;
2219 
2220         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2221                 const char *name = info->strtab + sym[i].st_name;
2222 
2223                 switch (sym[i].st_shndx) {
2224                 case SHN_COMMON:
2225                         /* Ignore common symbols */
2226                         if (!strncmp(name, "__gnu_lto", 9))
2227                                 break;
2228 
2229                         /* We compiled with -fno-common.  These are not
2230                            supposed to happen.  */
2231                         pr_debug("Common symbol: %s\n", name);
2232                         pr_warn("%s: please compile with -fno-common\n",
2233                                mod->name);
2234                         ret = -ENOEXEC;
2235                         break;
2236 
2237                 case SHN_ABS:
2238                         /* Don't need to do anything */
2239                         pr_debug("Absolute symbol: 0x%08lx\n",
2240                                (long)sym[i].st_value);
2241                         break;
2242 
2243                 case SHN_LIVEPATCH:
2244                         /* Livepatch symbols are resolved by livepatch */
2245                         break;
2246 
2247                 case SHN_UNDEF:
2248                         ksym = resolve_symbol_wait(mod, info, name);
2249                         /* Ok if resolved.  */
2250                         if (ksym && !IS_ERR(ksym)) {
2251                                 sym[i].st_value = ksym->value;
2252                                 break;
2253                         }
2254 
2255                         /* Ok if weak.  */
2256                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2257                                 break;
2258 
2259                         pr_warn("%s: Unknown symbol %s (err %li)\n",
2260                                 mod->name, name, PTR_ERR(ksym));
2261                         ret = PTR_ERR(ksym) ?: -ENOENT;
2262                         break;
2263 
2264                 default:
2265                         /* Divert to percpu allocation if a percpu var. */
2266                         if (sym[i].st_shndx == info->index.pcpu)
2267                                 secbase = (unsigned long)mod_percpu(mod);
2268                         else
2269                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2270                         sym[i].st_value += secbase;
2271                         break;
2272                 }
2273         }
2274 
2275         return ret;
2276 }
2277 
2278 static int apply_relocations(struct module *mod, const struct load_info *info)
2279 {
2280         unsigned int i;
2281         int err = 0;
2282 
2283         /* Now do relocations. */
2284         for (i = 1; i < info->hdr->e_shnum; i++) {
2285                 unsigned int infosec = info->sechdrs[i].sh_info;
2286 
2287                 /* Not a valid relocation section? */
2288                 if (infosec >= info->hdr->e_shnum)
2289                         continue;
2290 
2291                 /* Don't bother with non-allocated sections */
2292                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2293                         continue;
2294 
2295                 /* Livepatch relocation sections are applied by livepatch */
2296                 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2297                         continue;
2298 
2299                 if (info->sechdrs[i].sh_type == SHT_REL)
2300                         err = apply_relocate(info->sechdrs, info->strtab,
2301                                              info->index.sym, i, mod);
2302                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2303                         err = apply_relocate_add(info->sechdrs, info->strtab,
2304                                                  info->index.sym, i, mod);
2305                 if (err < 0)
2306                         break;
2307         }
2308         return err;
2309 }
2310 
2311 /* Additional bytes needed by arch in front of individual sections */
2312 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2313                                              unsigned int section)
2314 {
2315         /* default implementation just returns zero */
2316         return 0;
2317 }
2318 
2319 /* Update size with this section: return offset. */
2320 static long get_offset(struct module *mod, unsigned int *size,
2321                        Elf_Shdr *sechdr, unsigned int section)
2322 {
2323         long ret;
2324 
2325         *size += arch_mod_section_prepend(mod, section);
2326         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2327         *size = ret + sechdr->sh_size;
2328         return ret;
2329 }
2330 
2331 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2332    might -- code, read-only data, read-write data, small data.  Tally
2333    sizes, and place the offsets into sh_entsize fields: high bit means it
2334    belongs in init. */
2335 static void layout_sections(struct module *mod, struct load_info *info)
2336 {
2337         static unsigned long const masks[][2] = {
2338                 /* NOTE: all executable code must be the first section
2339                  * in this array; otherwise modify the text_size
2340                  * finder in the two loops below */
2341                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2342                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2343                 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2344                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2345                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2346         };
2347         unsigned int m, i;
2348 
2349         for (i = 0; i < info->hdr->e_shnum; i++)
2350                 info->sechdrs[i].sh_entsize = ~0UL;
2351 
2352         pr_debug("Core section allocation order:\n");
2353         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2354                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2355                         Elf_Shdr *s = &info->sechdrs[i];
2356                         const char *sname = info->secstrings + s->sh_name;
2357 
2358                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2359                             || (s->sh_flags & masks[m][1])
2360                             || s->sh_entsize != ~0UL
2361                             || strstarts(sname, ".init"))
2362                                 continue;
2363                         s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2364                         pr_debug("\t%s\n", sname);
2365                 }
2366                 switch (m) {
2367                 case 0: /* executable */
2368                         mod->core_layout.size = debug_align(mod->core_layout.size);
2369                         mod->core_layout.text_size = mod->core_layout.size;
2370                         break;
2371                 case 1: /* RO: text and ro-data */
2372                         mod->core_layout.size = debug_align(mod->core_layout.size);
2373                         mod->core_layout.ro_size = mod->core_layout.size;
2374                         break;
2375                 case 2: /* RO after init */
2376                         mod->core_layout.size = debug_align(mod->core_layout.size);
2377                         mod->core_layout.ro_after_init_size = mod->core_layout.size;
2378                         break;
2379                 case 4: /* whole core */
2380                         mod->core_layout.size = debug_align(mod->core_layout.size);
2381                         break;
2382                 }
2383         }
2384 
2385         pr_debug("Init section allocation order:\n");
2386         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2387                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2388                         Elf_Shdr *s = &info->sechdrs[i];
2389                         const char *sname = info->secstrings + s->sh_name;
2390 
2391                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2392                             || (s->sh_flags & masks[m][1])
2393                             || s->sh_entsize != ~0UL
2394                             || !strstarts(sname, ".init"))
2395                                 continue;
2396                         s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2397                                          | INIT_OFFSET_MASK);
2398                         pr_debug("\t%s\n", sname);
2399                 }
2400                 switch (m) {
2401                 case 0: /* executable */
2402                         mod->init_layout.size = debug_align(mod->init_layout.size);
2403                         mod->init_layout.text_size = mod->init_layout.size;
2404                         break;
2405                 case 1: /* RO: text and ro-data */
2406                         mod->init_layout.size = debug_align(mod->init_layout.size);
2407                         mod->init_layout.ro_size = mod->init_layout.size;
2408                         break;
2409                 case 2:
2410                         /*
2411                          * RO after init doesn't apply to init_layout (only
2412                          * core_layout), so it just takes the value of ro_size.
2413                          */
2414                         mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2415                         break;
2416                 case 4: /* whole init */
2417                         mod->init_layout.size = debug_align(mod->init_layout.size);
2418                         break;
2419                 }
2420         }
2421 }
2422 
2423 static void set_license(struct module *mod, const char *license)
2424 {
2425         if (!license)
2426                 license = "unspecified";
2427 
2428         if (!license_is_gpl_compatible(license)) {
2429                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2430                         pr_warn("%s: module license '%s' taints kernel.\n",
2431                                 mod->name, license);
2432                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2433                                  LOCKDEP_NOW_UNRELIABLE);
2434         }
2435 }
2436 
2437 /* Parse tag=value strings from .modinfo section */
2438 static char *next_string(char *string, unsigned long *secsize)
2439 {
2440         /* Skip non-zero chars */
2441         while (string[0]) {
2442                 string++;
2443                 if ((*secsize)-- <= 1)
2444                         return NULL;
2445         }
2446 
2447         /* Skip any zero padding. */
2448         while (!string[0]) {
2449                 string++;
2450                 if ((*secsize)-- <= 1)
2451                         return NULL;
2452         }
2453         return string;
2454 }
2455 
2456 static char *get_modinfo(struct load_info *info, const char *tag)
2457 {
2458         char *p;
2459         unsigned int taglen = strlen(tag);
2460         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2461         unsigned long size = infosec->sh_size;
2462 
2463         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2464                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2465                         return p + taglen + 1;
2466         }
2467         return NULL;
2468 }
2469 
2470 static void setup_modinfo(struct module *mod, struct load_info *info)
2471 {
2472         struct module_attribute *attr;
2473         int i;
2474 
2475         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2476                 if (attr->setup)
2477                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2478         }
2479 }
2480 
2481 static void free_modinfo(struct module *mod)
2482 {
2483         struct module_attribute *attr;
2484         int i;
2485 
2486         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2487                 if (attr->free)
2488                         attr->free(mod);
2489         }
2490 }
2491 
2492 #ifdef CONFIG_KALLSYMS
2493 
2494 /* lookup symbol in given range of kernel_symbols */
2495 static const struct kernel_symbol *lookup_symbol(const char *name,
2496         const struct kernel_symbol *start,
2497         const struct kernel_symbol *stop)
2498 {
2499         return bsearch(name, start, stop - start,
2500                         sizeof(struct kernel_symbol), cmp_name);
2501 }
2502 
2503 static int is_exported(const char *name, unsigned long value,
2504                        const struct module *mod)
2505 {
2506         const struct kernel_symbol *ks;
2507         if (!mod)
2508                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2509         else
2510                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2511         return ks != NULL && ks->value == value;
2512 }
2513 
2514 /* As per nm */
2515 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2516 {
2517         const Elf_Shdr *sechdrs = info->sechdrs;
2518 
2519         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2520                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2521                         return 'v';
2522                 else
2523                         return 'w';
2524         }
2525         if (sym->st_shndx == SHN_UNDEF)
2526                 return 'U';
2527         if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2528                 return 'a';
2529         if (sym->st_shndx >= SHN_LORESERVE)
2530                 return '?';
2531         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2532                 return 't';
2533         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2534             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2535                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2536                         return 'r';
2537                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2538                         return 'g';
2539                 else
2540                         return 'd';
2541         }
2542         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2543                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2544                         return 's';
2545                 else
2546                         return 'b';
2547         }
2548         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2549                       ".debug")) {
2550                 return 'n';
2551         }
2552         return '?';
2553 }
2554 
2555 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2556                         unsigned int shnum, unsigned int pcpundx)
2557 {
2558         const Elf_Shdr *sec;
2559 
2560         if (src->st_shndx == SHN_UNDEF
2561             || src->st_shndx >= shnum
2562             || !src->st_name)
2563                 return false;
2564 
2565 #ifdef CONFIG_KALLSYMS_ALL
2566         if (src->st_shndx == pcpundx)
2567                 return true;
2568 #endif
2569 
2570         sec = sechdrs + src->st_shndx;
2571         if (!(sec->sh_flags & SHF_ALLOC)
2572 #ifndef CONFIG_KALLSYMS_ALL
2573             || !(sec->sh_flags & SHF_EXECINSTR)
2574 #endif
2575             || (sec->sh_entsize & INIT_OFFSET_MASK))
2576                 return false;
2577 
2578         return true;
2579 }
2580 
2581 /*
2582  * We only allocate and copy the strings needed by the parts of symtab
2583  * we keep.  This is simple, but has the effect of making multiple
2584  * copies of duplicates.  We could be more sophisticated, see
2585  * linux-kernel thread starting with
2586  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2587  */
2588 static void layout_symtab(struct module *mod, struct load_info *info)
2589 {
2590         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2591         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2592         const Elf_Sym *src;
2593         unsigned int i, nsrc, ndst, strtab_size = 0;
2594 
2595         /* Put symbol section at end of init part of module. */
2596         symsect->sh_flags |= SHF_ALLOC;
2597         symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2598                                          info->index.sym) | INIT_OFFSET_MASK;
2599         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2600 
2601         src = (void *)info->hdr + symsect->sh_offset;
2602         nsrc = symsect->sh_size / sizeof(*src);
2603 
2604         /* Compute total space required for the core symbols' strtab. */
2605         for (ndst = i = 0; i < nsrc; i++) {
2606                 if (i == 0 || is_livepatch_module(mod) ||
2607                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2608                                    info->index.pcpu)) {
2609                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2610                         ndst++;
2611                 }
2612         }
2613 
2614         /* Append room for core symbols at end of core part. */
2615         info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2616         info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2617         mod->core_layout.size += strtab_size;
2618         mod->core_layout.size = debug_align(mod->core_layout.size);
2619 
2620         /* Put string table section at end of init part of module. */
2621         strsect->sh_flags |= SHF_ALLOC;
2622         strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2623                                          info->index.str) | INIT_OFFSET_MASK;
2624         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2625 
2626         /* We'll tack temporary mod_kallsyms on the end. */
2627         mod->init_layout.size = ALIGN(mod->init_layout.size,
2628                                       __alignof__(struct mod_kallsyms));
2629         info->mod_kallsyms_init_off = mod->init_layout.size;
2630         mod->init_layout.size += sizeof(struct mod_kallsyms);
2631         mod->init_layout.size = debug_align(mod->init_layout.size);
2632 }
2633 
2634 /*
2635  * We use the full symtab and strtab which layout_symtab arranged to
2636  * be appended to the init section.  Later we switch to the cut-down
2637  * core-only ones.
2638  */
2639 static void add_kallsyms(struct module *mod, const struct load_info *info)
2640 {
2641         unsigned int i, ndst;
2642         const Elf_Sym *src;
2643         Elf_Sym *dst;
2644         char *s;
2645         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2646 
2647         /* Set up to point into init section. */
2648         mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2649 
2650         mod->kallsyms->symtab = (void *)symsec->sh_addr;
2651         mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2652         /* Make sure we get permanent strtab: don't use info->strtab. */
2653         mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2654 
2655         /* Set types up while we still have access to sections. */
2656         for (i = 0; i < mod->kallsyms->num_symtab; i++)
2657                 mod->kallsyms->symtab[i].st_info
2658                         = elf_type(&mod->kallsyms->symtab[i], info);
2659 
2660         /* Now populate the cut down core kallsyms for after init. */
2661         mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2662         mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2663         src = mod->kallsyms->symtab;
2664         for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2665                 if (i == 0 || is_livepatch_module(mod) ||
2666                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2667                                    info->index.pcpu)) {
2668                         dst[ndst] = src[i];
2669                         dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2670                         s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2671                                      KSYM_NAME_LEN) + 1;
2672                 }
2673         }
2674         mod->core_kallsyms.num_symtab = ndst;
2675 }
2676 #else
2677 static inline void layout_symtab(struct module *mod, struct load_info *info)
2678 {
2679 }
2680 
2681 static void add_kallsyms(struct module *mod, const struct load_info *info)
2682 {
2683 }
2684 #endif /* CONFIG_KALLSYMS */
2685 
2686 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2687 {
2688         if (!debug)
2689                 return;
2690 #ifdef CONFIG_DYNAMIC_DEBUG
2691         if (ddebug_add_module(debug, num, debug->modname))
2692                 pr_err("dynamic debug error adding module: %s\n",
2693                         debug->modname);
2694 #endif
2695 }
2696 
2697 static void dynamic_debug_remove(struct _ddebug *debug)
2698 {
2699         if (debug)
2700                 ddebug_remove_module(debug->modname);
2701 }
2702 
2703 void * __weak module_alloc(unsigned long size)
2704 {
2705         return vmalloc_exec(size);
2706 }
2707 
2708 #ifdef CONFIG_DEBUG_KMEMLEAK
2709 static void kmemleak_load_module(const struct module *mod,
2710                                  const struct load_info *info)
2711 {
2712         unsigned int i;
2713 
2714         /* only scan the sections containing data */
2715         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2716 
2717         for (i = 1; i < info->hdr->e_shnum; i++) {
2718                 /* Scan all writable sections that's not executable */
2719                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2720                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2721                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2722                         continue;
2723 
2724                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2725                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2726         }
2727 }
2728 #else
2729 static inline void kmemleak_load_module(const struct module *mod,
2730                                         const struct load_info *info)
2731 {
2732 }
2733 #endif
2734 
2735 #ifdef CONFIG_MODULE_SIG
2736 static int module_sig_check(struct load_info *info, int flags)
2737 {
2738         int err = -ENOKEY;
2739         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2740         const void *mod = info->hdr;
2741 
2742         /*
2743          * Require flags == 0, as a module with version information
2744          * removed is no longer the module that was signed
2745          */
2746         if (flags == 0 &&
2747             info->len > markerlen &&
2748             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2749                 /* We truncate the module to discard the signature */
2750                 info->len -= markerlen;
2751                 err = mod_verify_sig(mod, &info->len);
2752         }
2753 
2754         if (!err) {
2755                 info->sig_ok = true;
2756                 return 0;
2757         }
2758 
2759         /* Not having a signature is only an error if we're strict. */
2760         if (err == -ENOKEY && !sig_enforce)
2761                 err = 0;
2762 
2763         return err;
2764 }
2765 #else /* !CONFIG_MODULE_SIG */
2766 static int module_sig_check(struct load_info *info, int flags)
2767 {
2768         return 0;
2769 }
2770 #endif /* !CONFIG_MODULE_SIG */
2771 
2772 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2773 static int elf_header_check(struct load_info *info)
2774 {
2775         if (info->len < sizeof(*(info->hdr)))
2776                 return -ENOEXEC;
2777 
2778         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2779             || info->hdr->e_type != ET_REL
2780             || !elf_check_arch(info->hdr)
2781             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2782                 return -ENOEXEC;
2783 
2784         if (info->hdr->e_shoff >= info->len
2785             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2786                 info->len - info->hdr->e_shoff))
2787                 return -ENOEXEC;
2788 
2789         return 0;
2790 }
2791 
2792 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2793 
2794 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2795 {
2796         do {
2797                 unsigned long n = min(len, COPY_CHUNK_SIZE);
2798 
2799                 if (copy_from_user(dst, usrc, n) != 0)
2800                         return -EFAULT;
2801                 cond_resched();
2802                 dst += n;
2803                 usrc += n;
2804                 len -= n;
2805         } while (len);
2806         return 0;
2807 }
2808 
2809 #ifdef CONFIG_LIVEPATCH
2810 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2811 {
2812         if (get_modinfo(info, "livepatch")) {
2813                 mod->klp = true;
2814                 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2815         }
2816 
2817         return 0;
2818 }
2819 #else /* !CONFIG_LIVEPATCH */
2820 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2821 {
2822         if (get_modinfo(info, "livepatch")) {
2823                 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2824                        mod->name);
2825                 return -ENOEXEC;
2826         }
2827 
2828         return 0;
2829 }
2830 #endif /* CONFIG_LIVEPATCH */
2831 
2832 /* Sets info->hdr and info->len. */
2833 static int copy_module_from_user(const void __user *umod, unsigned long len,
2834                                   struct load_info *info)
2835 {
2836         int err;
2837 
2838         info->len = len;
2839         if (info->len < sizeof(*(info->hdr)))
2840                 return -ENOEXEC;
2841 
2842         err = security_kernel_read_file(NULL, READING_MODULE);
2843         if (err)
2844                 return err;
2845 
2846         /* Suck in entire file: we'll want most of it. */
2847         info->hdr = __vmalloc(info->len,
2848                         GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2849         if (!info->hdr)
2850                 return -ENOMEM;
2851 
2852         if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2853                 vfree(info->hdr);
2854                 return -EFAULT;
2855         }
2856 
2857         return 0;
2858 }
2859 
2860 static void free_copy(struct load_info *info)
2861 {
2862         vfree(info->hdr);
2863 }
2864 
2865 static int rewrite_section_headers(struct load_info *info, int flags)
2866 {
2867         unsigned int i;
2868 
2869         /* This should always be true, but let's be sure. */
2870         info->sechdrs[0].sh_addr = 0;
2871 
2872         for (i = 1; i < info->hdr->e_shnum; i++) {
2873                 Elf_Shdr *shdr = &info->sechdrs[i];
2874                 if (shdr->sh_type != SHT_NOBITS
2875                     && info->len < shdr->sh_offset + shdr->sh_size) {
2876                         pr_err("Module len %lu truncated\n", info->len);
2877                         return -ENOEXEC;
2878                 }
2879 
2880                 /* Mark all sections sh_addr with their address in the
2881                    temporary image. */
2882                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2883 
2884 #ifndef CONFIG_MODULE_UNLOAD
2885                 /* Don't load .exit sections */
2886                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2887                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2888 #endif
2889         }
2890 
2891         /* Track but don't keep modinfo and version sections. */
2892         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2893                 info->index.vers = 0; /* Pretend no __versions section! */
2894         else
2895                 info->index.vers = find_sec(info, "__versions");
2896         info->index.info = find_sec(info, ".modinfo");
2897         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2898         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2899         return 0;
2900 }
2901 
2902 /*
2903  * Set up our basic convenience variables (pointers to section headers,
2904  * search for module section index etc), and do some basic section
2905  * verification.
2906  *
2907  * Return the temporary module pointer (we'll replace it with the final
2908  * one when we move the module sections around).
2909  */
2910 static struct module *setup_load_info(struct load_info *info, int flags)
2911 {
2912         unsigned int i;
2913         int err;
2914         struct module *mod;
2915 
2916         /* Set up the convenience variables */
2917         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2918         info->secstrings = (void *)info->hdr
2919                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2920 
2921         err = rewrite_section_headers(info, flags);
2922         if (err)
2923                 return ERR_PTR(err);
2924 
2925         /* Find internal symbols and strings. */
2926         for (i = 1; i < info->hdr->e_shnum; i++) {
2927                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2928                         info->index.sym = i;
2929                         info->index.str = info->sechdrs[i].sh_link;
2930                         info->strtab = (char *)info->hdr
2931                                 + info->sechdrs[info->index.str].sh_offset;
2932                         break;
2933                 }
2934         }
2935 
2936         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2937         if (!info->index.mod) {
2938                 pr_warn("No module found in object\n");
2939                 return ERR_PTR(-ENOEXEC);
2940         }
2941         /* This is temporary: point mod into copy of data. */
2942         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2943 
2944         if (info->index.sym == 0) {
2945                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2946                 return ERR_PTR(-ENOEXEC);
2947         }
2948 
2949         info->index.pcpu = find_pcpusec(info);
2950 
2951         /* Check module struct version now, before we try to use module. */
2952         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2953                 return ERR_PTR(-ENOEXEC);
2954 
2955         return mod;
2956 }
2957 
2958 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2959 {
2960         const char *modmagic = get_modinfo(info, "vermagic");
2961         int err;
2962 
2963         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2964                 modmagic = NULL;
2965 
2966         /* This is allowed: modprobe --force will invalidate it. */
2967         if (!modmagic) {
2968                 err = try_to_force_load(mod, "bad vermagic");
2969                 if (err)
2970                         return err;
2971         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2972                 pr_err("%s: version magic '%s' should be '%s'\n",
2973                        mod->name, modmagic, vermagic);
2974                 return -ENOEXEC;
2975         }
2976 
2977         if (!get_modinfo(info, "intree")) {
2978                 if (!test_taint(TAINT_OOT_MODULE))
2979                         pr_warn("%s: loading out-of-tree module taints kernel.\n",
2980                                 mod->name);
2981                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2982         }
2983 
2984         if (get_modinfo(info, "staging")) {
2985                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2986                 pr_warn("%s: module is from the staging directory, the quality "
2987                         "is unknown, you have been warned.\n", mod->name);
2988         }
2989 
2990         err = check_modinfo_livepatch(mod, info);
2991         if (err)
2992                 return err;
2993 
2994         /* Set up license info based on the info section */
2995         set_license(mod, get_modinfo(info, "license"));
2996 
2997         return 0;
2998 }
2999 
3000 static int find_module_sections(struct module *mod, struct load_info *info)
3001 {
3002         mod->kp = section_objs(info, "__param",
3003                                sizeof(*mod->kp), &mod->num_kp);
3004         mod->syms = section_objs(info, "__ksymtab",
3005                                  sizeof(*mod->syms), &mod->num_syms);
3006         mod->crcs = section_addr(info, "__kcrctab");
3007         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3008                                      sizeof(*mod->gpl_syms),
3009                                      &mod->num_gpl_syms);
3010         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3011         mod->gpl_future_syms = section_objs(info,
3012                                             "__ksymtab_gpl_future",
3013                                             sizeof(*mod->gpl_future_syms),
3014                                             &mod->num_gpl_future_syms);
3015         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3016 
3017 #ifdef CONFIG_UNUSED_SYMBOLS
3018         mod->unused_syms = section_objs(info, "__ksymtab_unused",
3019                                         sizeof(*mod->unused_syms),
3020                                         &mod->num_unused_syms);
3021         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3022         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3023                                             sizeof(*mod->unused_gpl_syms),
3024                                             &mod->num_unused_gpl_syms);
3025         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3026 #endif
3027 #ifdef CONFIG_CONSTRUCTORS
3028         mod->ctors = section_objs(info, ".ctors",
3029                                   sizeof(*mod->ctors), &mod->num_ctors);
3030         if (!mod->ctors)
3031                 mod->ctors = section_objs(info, ".init_array",
3032                                 sizeof(*mod->ctors), &mod->num_ctors);
3033         else if (find_sec(info, ".init_array")) {
3034                 /*
3035                  * This shouldn't happen with same compiler and binutils
3036                  * building all parts of the module.
3037                  */
3038                 pr_warn("%s: has both .ctors and .init_array.\n",
3039                        mod->name);
3040                 return -EINVAL;
3041         }
3042 #endif
3043 
3044 #ifdef CONFIG_TRACEPOINTS
3045         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3046                                              sizeof(*mod->tracepoints_ptrs),
3047                                              &mod->num_tracepoints);
3048 #endif
3049 #ifdef HAVE_JUMP_LABEL
3050         mod->jump_entries = section_objs(info, "__jump_table",
3051                                         sizeof(*mod->jump_entries),
3052                                         &mod->num_jump_entries);
3053 #endif
3054 #ifdef CONFIG_EVENT_TRACING
3055         mod->trace_events = section_objs(info, "_ftrace_events",
3056                                          sizeof(*mod->trace_events),
3057                                          &mod->num_trace_events);
3058         mod->trace_enums = section_objs(info, "_ftrace_enum_map",
3059                                         sizeof(*mod->trace_enums),
3060                                         &mod->num_trace_enums);
3061 #endif
3062 #ifdef CONFIG_TRACING
3063         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3064                                          sizeof(*mod->trace_bprintk_fmt_start),
3065                                          &mod->num_trace_bprintk_fmt);
3066 #endif
3067 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3068         /* sechdrs[0].sh_size is always zero */
3069         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3070                                              sizeof(*mod->ftrace_callsites),
3071                                              &mod->num_ftrace_callsites);
3072 #endif
3073 
3074         mod->extable = section_objs(info, "__ex_table",
3075                                     sizeof(*mod->extable), &mod->num_exentries);
3076 
3077         if (section_addr(info, "__obsparm"))
3078                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3079 
3080         info->debug = section_objs(info, "__verbose",
3081                                    sizeof(*info->debug), &info->num_debug);
3082 
3083         return 0;
3084 }
3085 
3086 static int move_module(struct module *mod, struct load_info *info)
3087 {
3088         int i;
3089         void *ptr;
3090 
3091         /* Do the allocs. */
3092         ptr = module_alloc(mod->core_layout.size);
3093         /*
3094          * The pointer to this block is stored in the module structure
3095          * which is inside the block. Just mark it as not being a
3096          * leak.
3097          */
3098         kmemleak_not_leak(ptr);
3099         if (!ptr)
3100                 return -ENOMEM;
3101 
3102         memset(ptr, 0, mod->core_layout.size);
3103         mod->core_layout.base = ptr;
3104 
3105         if (mod->init_layout.size) {
3106                 ptr = module_alloc(mod->init_layout.size);
3107                 /*
3108                  * The pointer to this block is stored in the module structure
3109                  * which is inside the block. This block doesn't need to be
3110                  * scanned as it contains data and code that will be freed
3111                  * after the module is initialized.
3112                  */
3113                 kmemleak_ignore(ptr);
3114                 if (!ptr) {
3115                         module_memfree(mod->core_layout.base);
3116                         return -ENOMEM;
3117                 }
3118                 memset(ptr, 0, mod->init_layout.size);
3119                 mod->init_layout.base = ptr;
3120         } else
3121                 mod->init_layout.base = NULL;
3122 
3123         /* Transfer each section which specifies SHF_ALLOC */
3124         pr_debug("final section addresses:\n");
3125         for (i = 0; i < info->hdr->e_shnum; i++) {
3126                 void *dest;
3127                 Elf_Shdr *shdr = &info->sechdrs[i];
3128 
3129                 if (!(shdr->sh_flags & SHF_ALLOC))
3130                         continue;
3131 
3132                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3133                         dest = mod->init_layout.base
3134                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3135                 else
3136                         dest = mod->core_layout.base + shdr->sh_entsize;
3137 
3138                 if (shdr->sh_type != SHT_NOBITS)
3139                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3140                 /* Update sh_addr to point to copy in image. */
3141                 shdr->sh_addr = (unsigned long)dest;
3142                 pr_debug("\t0x%lx %s\n",
3143                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3144         }
3145 
3146         return 0;
3147 }
3148 
3149 static int check_module_license_and_versions(struct module *mod)
3150 {
3151         int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3152 
3153         /*
3154          * ndiswrapper is under GPL by itself, but loads proprietary modules.
3155          * Don't use add_taint_module(), as it would prevent ndiswrapper from
3156          * using GPL-only symbols it needs.
3157          */
3158         if (strcmp(mod->name, "ndiswrapper") == 0)
3159                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3160 
3161         /* driverloader was caught wrongly pretending to be under GPL */
3162         if (strcmp(mod->name, "driverloader") == 0)
3163                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3164                                  LOCKDEP_NOW_UNRELIABLE);
3165 
3166         /* lve claims to be GPL but upstream won't provide source */
3167         if (strcmp(mod->name, "lve") == 0)
3168                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3169                                  LOCKDEP_NOW_UNRELIABLE);
3170 
3171         if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3172                 pr_warn("%s: module license taints kernel.\n", mod->name);
3173 
3174 #ifdef CONFIG_MODVERSIONS
3175         if ((mod->num_syms && !mod->crcs)
3176             || (mod->num_gpl_syms && !mod->gpl_crcs)
3177             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3178 #ifdef CONFIG_UNUSED_SYMBOLS
3179             || (mod->num_unused_syms && !mod->unused_crcs)
3180             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3181 #endif
3182                 ) {
3183                 return try_to_force_load(mod,
3184                                          "no versions for exported symbols");
3185         }
3186 #endif
3187         return 0;
3188 }
3189 
3190 static void flush_module_icache(const struct module *mod)
3191 {
3192         mm_segment_t old_fs;
3193 
3194         /* flush the icache in correct context */
3195         old_fs = get_fs();
3196         set_fs(KERNEL_DS);
3197 
3198         /*
3199          * Flush the instruction cache, since we've played with text.
3200          * Do it before processing of module parameters, so the module
3201          * can provide parameter accessor functions of its own.
3202          */
3203         if (mod->init_layout.base)
3204                 flush_icache_range((unsigned long)mod->init_layout.base,
3205                                    (unsigned long)mod->init_layout.base
3206                                    + mod->init_layout.size);
3207         flush_icache_range((unsigned long)mod->core_layout.base,
3208                            (unsigned long)mod->core_layout.base + mod->core_layout.size);
3209 
3210         set_fs(old_fs);
3211 }
3212 
3213 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3214                                      Elf_Shdr *sechdrs,
3215                                      char *secstrings,
3216                                      struct module *mod)
3217 {
3218         return 0;
3219 }
3220 
3221 /* module_blacklist is a comma-separated list of module names */
3222 static char *module_blacklist;
3223 static bool blacklisted(char *module_name)
3224 {
3225         const char *p;
3226         size_t len;
3227 
3228         if (!module_blacklist)
3229                 return false;
3230 
3231         for (p = module_blacklist; *p; p += len) {
3232                 len = strcspn(p, ",");
3233                 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3234                         return true;
3235                 if (p[len] == ',')
3236                         len++;
3237         }
3238         return false;
3239 }
3240 core_param(module_blacklist, module_blacklist, charp, 0400);
3241 
3242 static struct module *layout_and_allocate(struct load_info *info, int flags)
3243 {
3244         /* Module within temporary copy. */
3245         struct module *mod;
3246         unsigned int ndx;
3247         int err;
3248 
3249         mod = setup_load_info(info, flags);
3250         if (IS_ERR(mod))
3251                 return mod;
3252 
3253         if (blacklisted(mod->name))
3254                 return ERR_PTR(-EPERM);
3255 
3256         err = check_modinfo(mod, info, flags);
3257         if (err)
3258                 return ERR_PTR(err);
3259 
3260         /* Allow arches to frob section contents and sizes.  */
3261         err = module_frob_arch_sections(info->hdr, info->sechdrs,
3262                                         info->secstrings, mod);
3263         if (err < 0)
3264                 return ERR_PTR(err);
3265 
3266         /* We will do a special allocation for per-cpu sections later. */
3267         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3268 
3269         /*
3270          * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3271          * layout_sections() can put it in the right place.
3272          * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3273          */
3274         ndx = find_sec(info, ".data..ro_after_init");
3275         if (ndx)
3276                 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3277 
3278         /* Determine total sizes, and put offsets in sh_entsize.  For now
3279            this is done generically; there doesn't appear to be any
3280            special cases for the architectures. */
3281         layout_sections(mod, info);
3282         layout_symtab(mod, info);
3283 
3284         /* Allocate and move to the final place */
3285         err = move_module(mod, info);
3286         if (err)
3287                 return ERR_PTR(err);
3288 
3289         /* Module has been copied to its final place now: return it. */
3290         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3291         kmemleak_load_module(mod, info);
3292         return mod;
3293 }
3294 
3295 /* mod is no longer valid after this! */
3296 static void module_deallocate(struct module *mod, struct load_info *info)
3297 {
3298         percpu_modfree(mod);
3299         module_arch_freeing_init(mod);
3300         module_memfree(mod->init_layout.base);
3301         module_memfree(mod->core_layout.base);
3302 }
3303 
3304 int __weak module_finalize(const Elf_Ehdr *hdr,
3305                            const Elf_Shdr *sechdrs,
3306                            struct module *me)
3307 {
3308         return 0;
3309 }
3310 
3311 static int post_relocation(struct module *mod, const struct load_info *info)
3312 {
3313         /* Sort exception table now relocations are done. */
3314         sort_extable(mod->extable, mod->extable + mod->num_exentries);
3315 
3316         /* Copy relocated percpu area over. */
3317         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3318                        info->sechdrs[info->index.pcpu].sh_size);
3319 
3320         /* Setup kallsyms-specific fields. */
3321         add_kallsyms(mod, info);
3322 
3323         /* Arch-specific module finalizing. */
3324         return module_finalize(info->hdr, info->sechdrs, mod);
3325 }
3326 
3327 /* Is this module of this name done loading?  No locks held. */
3328 static bool finished_loading(const char *name)
3329 {
3330         struct module *mod;
3331         bool ret;
3332 
3333         /*
3334          * The module_mutex should not be a heavily contended lock;
3335          * if we get the occasional sleep here, we'll go an extra iteration
3336          * in the wait_event_interruptible(), which is harmless.
3337          */
3338         sched_annotate_sleep();
3339         mutex_lock(&module_mutex);
3340         mod = find_module_all(name, strlen(name), true);
3341         ret = !mod || mod->state == MODULE_STATE_LIVE
3342                 || mod->state == MODULE_STATE_GOING;
3343         mutex_unlock(&module_mutex);
3344 
3345         return ret;
3346 }
3347 
3348 /* Call module constructors. */
3349 static void do_mod_ctors(struct module *mod)
3350 {
3351 #ifdef CONFIG_CONSTRUCTORS
3352         unsigned long i;
3353 
3354         for (i = 0; i < mod->num_ctors; i++)
3355                 mod->ctors[i]();
3356 #endif
3357 }
3358 
3359 /* For freeing module_init on success, in case kallsyms traversing */
3360 struct mod_initfree {
3361         struct rcu_head rcu;
3362         void *module_init;
3363 };
3364 
3365 static void do_free_init(struct rcu_head *head)
3366 {
3367         struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3368         module_memfree(m->module_init);
3369         kfree(m);
3370 }
3371 
3372 /*
3373  * This is where the real work happens.
3374  *
3375  * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3376  * helper command 'lx-symbols'.
3377  */
3378 static noinline int do_init_module(struct module *mod)
3379 {
3380         int ret = 0;
3381         struct mod_initfree *freeinit;
3382 
3383         freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3384         if (!freeinit) {
3385                 ret = -ENOMEM;
3386                 goto fail;
3387         }
3388         freeinit->module_init = mod->init_layout.base;
3389 
3390         /*
3391          * We want to find out whether @mod uses async during init.  Clear
3392          * PF_USED_ASYNC.  async_schedule*() will set it.
3393          */
3394         current->flags &= ~PF_USED_ASYNC;
3395 
3396         do_mod_ctors(mod);
3397         /* Start the module */
3398         if (mod->init != NULL)
3399                 ret = do_one_initcall(mod->init);
3400         if (ret < 0) {
3401                 goto fail_free_freeinit;
3402         }
3403         if (ret > 0) {
3404                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3405                         "follow 0/-E convention\n"
3406                         "%s: loading module anyway...\n",
3407                         __func__, mod->name, ret, __func__);
3408                 dump_stack();
3409         }
3410 
3411         /* Now it's a first class citizen! */
3412         mod->state = MODULE_STATE_LIVE;
3413         blocking_notifier_call_chain(&module_notify_list,
3414                                      MODULE_STATE_LIVE, mod);
3415 
3416         /*
3417          * We need to finish all async code before the module init sequence
3418          * is done.  This has potential to deadlock.  For example, a newly
3419          * detected block device can trigger request_module() of the
3420          * default iosched from async probing task.  Once userland helper
3421          * reaches here, async_synchronize_full() will wait on the async
3422          * task waiting on request_module() and deadlock.
3423          *
3424          * This deadlock is avoided by perfomring async_synchronize_full()
3425          * iff module init queued any async jobs.  This isn't a full
3426          * solution as it will deadlock the same if module loading from
3427          * async jobs nests more than once; however, due to the various
3428          * constraints, this hack seems to be the best option for now.
3429          * Please refer to the following thread for details.
3430          *
3431          * http://thread.gmane.org/gmane.linux.kernel/1420814
3432          */
3433         if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3434                 async_synchronize_full();
3435 
3436         mutex_lock(&module_mutex);
3437         /* Drop initial reference. */
3438         module_put(mod);
3439         trim_init_extable(mod);
3440 #ifdef CONFIG_KALLSYMS
3441         /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3442         rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3443 #endif
3444         module_enable_ro(mod, true);
3445         mod_tree_remove_init(mod);
3446         disable_ro_nx(&mod->init_layout);
3447         module_arch_freeing_init(mod);
3448         mod->init_layout.base = NULL;
3449         mod->init_layout.size = 0;
3450         mod->init_layout.ro_size = 0;
3451         mod->init_layout.ro_after_init_size = 0;
3452         mod->init_layout.text_size = 0;
3453         /*
3454          * We want to free module_init, but be aware that kallsyms may be
3455          * walking this with preempt disabled.  In all the failure paths, we
3456          * call synchronize_sched(), but we don't want to slow down the success
3457          * path, so use actual RCU here.
3458          */
3459         call_rcu_sched(&freeinit->rcu, do_free_init);
3460         mutex_unlock(&module_mutex);
3461         wake_up_all(&module_wq);
3462 
3463         return 0;
3464 
3465 fail_free_freeinit:
3466         kfree(freeinit);
3467 fail:
3468         /* Try to protect us from buggy refcounters. */
3469         mod->state = MODULE_STATE_GOING;
3470         synchronize_sched();
3471         module_put(mod);
3472         blocking_notifier_call_chain(&module_notify_list,
3473                                      MODULE_STATE_GOING, mod);
3474         klp_module_going(mod);
3475         ftrace_release_mod(mod);
3476         free_module(mod);
3477         wake_up_all(&module_wq);
3478         return ret;
3479 }
3480 
3481 static int may_init_module(void)
3482 {
3483         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3484                 return -EPERM;
3485         if (!ccs_capable(CCS_USE_KERNEL_MODULE))
3486                 return -EPERM;
3487 
3488         return 0;
3489 }
3490 
3491 /*
3492  * We try to place it in the list now to make sure it's unique before
3493  * we dedicate too many resources.  In particular, temporary percpu
3494  * memory exhaustion.
3495  */
3496 static int add_unformed_module(struct module *mod)
3497 {
3498         int err;
3499         struct module *old;
3500 
3501         mod->state = MODULE_STATE_UNFORMED;
3502 
3503 again:
3504         mutex_lock(&module_mutex);
3505         old = find_module_all(mod->name, strlen(mod->name), true);
3506         if (old != NULL) {
3507                 if (old->state == MODULE_STATE_COMING
3508                     || old->state == MODULE_STATE_UNFORMED) {
3509                         /* Wait in case it fails to load. */
3510                         mutex_unlock(&module_mutex);
3511                         err = wait_event_interruptible(module_wq,
3512                                                finished_loading(mod->name));
3513                         if (err)
3514                                 goto out_unlocked;
3515                         goto again;
3516                 }
3517                 err = -EEXIST;
3518                 goto out;
3519         }
3520         mod_update_bounds(mod);
3521         list_add_rcu(&mod->list, &modules);
3522         mod_tree_insert(mod);
3523         err = 0;
3524 
3525 out:
3526         mutex_unlock(&module_mutex);
3527 out_unlocked:
3528         return err;
3529 }
3530 
3531 static int complete_formation(struct module *mod, struct load_info *info)
3532 {
3533         int err;
3534 
3535         mutex_lock(&module_mutex);
3536 
3537         /* Find duplicate symbols (must be called under lock). */
3538         err = verify_export_symbols(mod);
3539         if (err < 0)
3540                 goto out;
3541 
3542         /* This relies on module_mutex for list integrity. */
3543         module_bug_finalize(info->hdr, info->sechdrs, mod);
3544 
3545         module_enable_ro(mod, false);
3546         module_enable_nx(mod);
3547 
3548         /* Mark state as coming so strong_try_module_get() ignores us,
3549          * but kallsyms etc. can see us. */
3550         mod->state = MODULE_STATE_COMING;
3551         mutex_unlock(&module_mutex);
3552 
3553         return 0;
3554 
3555 out:
3556         mutex_unlock(&module_mutex);
3557         return err;
3558 }
3559 
3560 static int prepare_coming_module(struct module *mod)
3561 {
3562         int err;
3563 
3564         ftrace_module_enable(mod);
3565         err = klp_module_coming(mod);
3566         if (err)
3567                 return err;
3568 
3569         blocking_notifier_call_chain(&module_notify_list,
3570                                      MODULE_STATE_COMING, mod);
3571         return 0;
3572 }
3573 
3574 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3575                                    void *arg)
3576 {
3577         struct module *mod = arg;
3578         int ret;
3579 
3580         if (strcmp(param, "async_probe") == 0) {
3581                 mod->async_probe_requested = true;
3582                 return 0;
3583         }
3584 
3585         /* Check for magic 'dyndbg' arg */
3586         ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3587         if (ret != 0)
3588                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3589         return 0;
3590 }
3591 
3592 /* Allocate and load the module: note that size of section 0 is always
3593    zero, and we rely on this for optional sections. */
3594 static int load_module(struct load_info *info, const char __user *uargs,
3595                        int flags)
3596 {
3597         struct module *mod;
3598         long err;
3599         char *after_dashes;
3600 
3601         err = module_sig_check(info, flags);
3602         if (err)
3603                 goto free_copy;
3604 
3605         err = elf_header_check(info);
3606         if (err)
3607                 goto free_copy;
3608 
3609         /* Figure out module layout, and allocate all the memory. */
3610         mod = layout_and_allocate(info, flags);
3611         if (IS_ERR(mod)) {
3612                 err = PTR_ERR(mod);
3613                 goto free_copy;
3614         }
3615 
3616         /* Reserve our place in the list. */
3617         err = add_unformed_module(mod);
3618         if (err)
3619                 goto free_module;
3620 
3621 #ifdef CONFIG_MODULE_SIG
3622         mod->sig_ok = info->sig_ok;
3623         if (!mod->sig_ok) {
3624                 pr_notice_once("%s: module verification failed: signature "
3625                                "and/or required key missing - tainting "
3626                                "kernel\n", mod->name);
3627                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3628         }
3629 #endif
3630 
3631         /* To avoid stressing percpu allocator, do this once we're unique. */
3632         err = percpu_modalloc(mod, info);
3633         if (err)
3634                 goto unlink_mod;
3635 
3636         /* Now module is in final location, initialize linked lists, etc. */
3637         err = module_unload_init(mod);
3638         if (err)
3639                 goto unlink_mod;
3640 
3641         init_param_lock(mod);
3642 
3643         /* Now we've got everything in the final locations, we can
3644          * find optional sections. */
3645         err = find_module_sections(mod, info);
3646         if (err)
3647                 goto free_unload;
3648 
3649         err = check_module_license_and_versions(mod);
3650         if (err)
3651                 goto free_unload;
3652 
3653         /* Set up MODINFO_ATTR fields */
3654         setup_modinfo(mod, info);
3655 
3656         /* Fix up syms, so that st_value is a pointer to location. */
3657         err = simplify_symbols(mod, info);
3658         if (err < 0)
3659                 goto free_modinfo;
3660 
3661         err = apply_relocations(mod, info);
3662         if (err < 0)
3663                 goto free_modinfo;
3664 
3665         err = post_relocation(mod, info);
3666         if (err < 0)
3667                 goto free_modinfo;
3668 
3669         flush_module_icache(mod);
3670 
3671         /* Now copy in args */
3672         mod->args = strndup_user(uargs, ~0UL >> 1);
3673         if (IS_ERR(mod->args)) {
3674                 err = PTR_ERR(mod->args);
3675                 goto free_arch_cleanup;
3676         }
3677 
3678         dynamic_debug_setup(info->debug, info->num_debug);
3679 
3680         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3681         ftrace_module_init(mod);
3682 
3683         /* Finally it's fully formed, ready to start executing. */
3684         err = complete_formation(mod, info);
3685         if (err)
3686                 goto ddebug_cleanup;
3687 
3688         err = prepare_coming_module(mod);
3689         if (err)
3690                 goto bug_cleanup;
3691 
3692         /* Module is ready to execute: parsing args may do that. */
3693         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3694                                   -32768, 32767, mod,
3695                                   unknown_module_param_cb);
3696         if (IS_ERR(after_dashes)) {
3697                 err = PTR_ERR(after_dashes);
3698                 goto coming_cleanup;
3699         } else if (after_dashes) {
3700                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3701                        mod->name, after_dashes);
3702         }
3703 
3704         /* Link in to syfs. */
3705         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3706         if (err < 0)
3707                 goto coming_cleanup;
3708 
3709         if (is_livepatch_module(mod)) {
3710                 err = copy_module_elf(mod, info);
3711                 if (err < 0)
3712                         goto sysfs_cleanup;
3713         }
3714 
3715         /* Get rid of temporary copy. */
3716         free_copy(info);
3717 
3718         /* Done! */
3719         trace_module_load(mod);
3720 
3721         return do_init_module(mod);
3722 
3723  sysfs_cleanup:
3724         mod_sysfs_teardown(mod);
3725  coming_cleanup:
3726         mod->state = MODULE_STATE_GOING;
3727         destroy_params(mod->kp, mod->num_kp);
3728         blocking_notifier_call_chain(&module_notify_list,
3729                                      MODULE_STATE_GOING, mod);
3730         klp_module_going(mod);
3731  bug_cleanup:
3732         /* module_bug_cleanup needs module_mutex protection */
3733         mutex_lock(&module_mutex);
3734         module_bug_cleanup(mod);
3735         mutex_unlock(&module_mutex);
3736 
3737         /* we can't deallocate the module until we clear memory protection */
3738         module_disable_ro(mod);
3739         module_disable_nx(mod);
3740 
3741  ddebug_cleanup:
3742         dynamic_debug_remove(info->debug);
3743         synchronize_sched();
3744         kfree(mod->args);
3745  free_arch_cleanup:
3746         module_arch_cleanup(mod);
3747  free_modinfo:
3748         free_modinfo(mod);
3749  free_unload:
3750         module_unload_free(mod);
3751  unlink_mod:
3752         mutex_lock(&module_mutex);
3753         /* Unlink carefully: kallsyms could be walking list. */
3754         list_del_rcu(&mod->list);
3755         mod_tree_remove(mod);
3756         wake_up_all(&module_wq);
3757         /* Wait for RCU-sched synchronizing before releasing mod->list. */
3758         synchronize_sched();
3759         mutex_unlock(&module_mutex);
3760  free_module:
3761         /*
3762          * Ftrace needs to clean up what it initialized.
3763          * This does nothing if ftrace_module_init() wasn't called,
3764          * but it must be called outside of module_mutex.
3765          */
3766         ftrace_release_mod(mod);
3767         /* Free lock-classes; relies on the preceding sync_rcu() */
3768         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3769 
3770         module_deallocate(mod, info);
3771  free_copy:
3772         free_copy(info);
3773         return err;
3774 }
3775 
3776 SYSCALL_DEFINE3(init_module, void __user *, umod,
3777                 unsigned long, len, const char __user *, uargs)
3778 {
3779         int err;
3780         struct load_info info = { };
3781 
3782         err = may_init_module();
3783         if (err)
3784                 return err;
3785 
3786         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3787                umod, len, uargs);
3788 
3789         err = copy_module_from_user(umod, len, &info);
3790         if (err)
3791                 return err;
3792 
3793         return load_module(&info, uargs, 0);
3794 }
3795 
3796 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3797 {
3798         struct load_info info = { };
3799         loff_t size;
3800         void *hdr;
3801         int err;
3802 
3803         err = may_init_module();
3804         if (err)
3805                 return err;
3806 
3807         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3808 
3809         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3810                       |MODULE_INIT_IGNORE_VERMAGIC))
3811                 return -EINVAL;
3812 
3813         err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3814                                        READING_MODULE);
3815         if (err)
3816                 return err;
3817         info.hdr = hdr;
3818         info.len = size;
3819 
3820         return load_module(&info, uargs, flags);
3821 }
3822 
3823 static inline int within(unsigned long addr, void *start, unsigned long size)
3824 {
3825         return ((void *)addr >= start && (void *)addr < start + size);
3826 }
3827 
3828 #ifdef CONFIG_KALLSYMS
3829 /*
3830  * This ignores the intensely annoying "mapping symbols" found
3831  * in ARM ELF files: $a, $t and $d.
3832  */
3833 static inline int is_arm_mapping_symbol(const char *str)
3834 {
3835         if (str[0] == '.' && str[1] == 'L')
3836                 return true;
3837         return str[0] == '$' && strchr("axtd", str[1])
3838                && (str[2] == '\0' || str[2] == '.');
3839 }
3840 
3841 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3842 {
3843         return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3844 }
3845 
3846 static const char *get_ksymbol(struct module *mod,
3847                                unsigned long addr,
3848                                unsigned long *size,
3849                                unsigned long *offset)
3850 {
3851         unsigned int i, best = 0;
3852         unsigned long nextval;
3853         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3854 
3855         /* At worse, next value is at end of module */
3856         if (within_module_init(addr, mod))
3857                 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3858         else
3859                 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3860 
3861         /* Scan for closest preceding symbol, and next symbol. (ELF
3862            starts real symbols at 1). */
3863         for (i = 1; i < kallsyms->num_symtab; i++) {
3864                 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3865                         continue;
3866 
3867                 /* We ignore unnamed symbols: they're uninformative
3868                  * and inserted at a whim. */
3869                 if (*symname(kallsyms, i) == '\0'
3870                     || is_arm_mapping_symbol(symname(kallsyms, i)))
3871                         continue;
3872 
3873                 if (kallsyms->symtab[i].st_value <= addr
3874                     && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3875                         best = i;
3876                 if (kallsyms->symtab[i].st_value > addr
3877                     && kallsyms->symtab[i].st_value < nextval)
3878                         nextval = kallsyms->symtab[i].st_value;
3879         }
3880 
3881         if (!best)
3882                 return NULL;
3883 
3884         if (size)
3885                 *size = nextval - kallsyms->symtab[best].st_value;
3886         if (offset)
3887                 *offset = addr - kallsyms->symtab[best].st_value;
3888         return symname(kallsyms, best);
3889 }
3890 
3891 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3892  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3893 const char *module_address_lookup(unsigned long addr,
3894                             unsigned long *size,
3895                             unsigned long *offset,
3896                             char **modname,
3897                             char *namebuf)
3898 {
3899         const char *ret = NULL;
3900         struct module *mod;
3901 
3902         preempt_disable();
3903         mod = __module_address(addr);
3904         if (mod) {
3905                 if (modname)
3906                         *modname = mod->name;
3907                 ret = get_ksymbol(mod, addr, size, offset);
3908         }
3909         /* Make a copy in here where it's safe */
3910         if (ret) {
3911                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3912                 ret = namebuf;
3913         }
3914         preempt_enable();
3915 
3916         return ret;
3917 }
3918 
3919 int lookup_module_symbol_name(unsigned long addr, char *symname)
3920 {
3921         struct module *mod;
3922 
3923         preempt_disable();
3924         list_for_each_entry_rcu(mod, &modules, list) {
3925                 if (mod->state == MODULE_STATE_UNFORMED)
3926                         continue;
3927                 if (within_module(addr, mod)) {
3928                         const char *sym;
3929 
3930                         sym = get_ksymbol(mod, addr, NULL, NULL);
3931                         if (!sym)
3932                                 goto out;
3933                         strlcpy(symname, sym, KSYM_NAME_LEN);
3934                         preempt_enable();
3935                         return 0;
3936                 }
3937         }
3938 out:
3939         preempt_enable();
3940         return -ERANGE;
3941 }
3942 
3943 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3944                         unsigned long *offset, char *modname, char *name)
3945 {
3946         struct module *mod;
3947 
3948         preempt_disable();
3949         list_for_each_entry_rcu(mod, &modules, list) {
3950                 if (mod->state == MODULE_STATE_UNFORMED)
3951                         continue;
3952                 if (within_module(addr, mod)) {
3953                         const char *sym;
3954 
3955                         sym = get_ksymbol(mod, addr, size, offset);
3956                         if (!sym)
3957                                 goto out;
3958                         if (modname)
3959                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3960                         if (name)
3961                                 strlcpy(name, sym, KSYM_NAME_LEN);
3962                         preempt_enable();
3963                         return 0;
3964                 }
3965         }
3966 out:
3967         preempt_enable();
3968         return -ERANGE;
3969 }
3970 
3971 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3972                         char *name, char *module_name, int *exported)
3973 {
3974         struct module *mod;
3975 
3976         preempt_disable();
3977         list_for_each_entry_rcu(mod, &modules, list) {
3978                 struct mod_kallsyms *kallsyms;
3979 
3980                 if (mod->state == MODULE_STATE_UNFORMED)
3981                         continue;
3982                 kallsyms = rcu_dereference_sched(mod->kallsyms);
3983                 if (symnum < kallsyms->num_symtab) {
3984                         *value = kallsyms->symtab[symnum].st_value;
3985                         *type = kallsyms->symtab[symnum].st_info;
3986                         strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
3987                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3988                         *exported = is_exported(name, *value, mod);
3989                         preempt_enable();
3990                         return 0;
3991                 }
3992                 symnum -= kallsyms->num_symtab;
3993         }
3994         preempt_enable();
3995         return -ERANGE;
3996 }
3997 
3998 static unsigned long mod_find_symname(struct module *mod, const char *name)
3999 {
4000         unsigned int i;
4001         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4002 
4003         for (i = 0; i < kallsyms->num_symtab; i++)
4004                 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4005                     kallsyms->symtab[i].st_info != 'U')
4006                         return kallsyms->symtab[i].st_value;
4007         return 0;
4008 }
4009 
4010 /* Look for this name: can be of form module:name. */
4011 unsigned long module_kallsyms_lookup_name(const char *name)
4012 {
4013         struct module *mod;
4014         char *colon;
4015         unsigned long ret = 0;
4016 
4017         /* Don't lock: we're in enough trouble already. */
4018         preempt_disable();
4019         if ((colon = strchr(name, ':')) != NULL) {
4020                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4021                         ret = mod_find_symname(mod, colon+1);
4022         } else {
4023                 list_for_each_entry_rcu(mod, &modules, list) {
4024                         if (mod->state == MODULE_STATE_UNFORMED)
4025                                 continue;
4026                         if ((ret = mod_find_symname(mod, name)) != 0)
4027                                 break;
4028                 }
4029         }
4030         preempt_enable();
4031         return ret;
4032 }
4033 
4034 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4035                                              struct module *, unsigned long),
4036                                    void *data)
4037 {
4038         struct module *mod;
4039         unsigned int i;
4040         int ret;
4041 
4042         module_assert_mutex();
4043 
4044         list_for_each_entry(mod, &modules, list) {
4045                 /* We hold module_mutex: no need for rcu_dereference_sched */
4046                 struct mod_kallsyms *kallsyms = mod->kallsyms;
4047 
4048                 if (mod->state == MODULE_STATE_UNFORMED)
4049                         continue;
4050                 for (i = 0; i < kallsyms->num_symtab; i++) {
4051                         ret = fn(data, symname(kallsyms, i),
4052                                  mod, kallsyms->symtab[i].st_value);
4053                         if (ret != 0)
4054                                 return ret;
4055                 }
4056         }
4057         return 0;
4058 }
4059 #endif /* CONFIG_KALLSYMS */
4060 
4061 /* Maximum number of characters written by module_flags() */
4062 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4063 
4064 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4065 static char *module_flags(struct module *mod, char *buf)
4066 {
4067         int bx = 0;
4068 
4069         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4070         if (mod->taints ||
4071             mod->state == MODULE_STATE_GOING ||
4072             mod->state == MODULE_STATE_COMING) {
4073                 buf[bx++] = '(';
4074                 bx += module_flags_taint(mod, buf + bx);
4075                 /* Show a - for module-is-being-unloaded */
4076                 if (mod->state == MODULE_STATE_GOING)
4077                         buf[bx++] = '-';
4078                 /* Show a + for module-is-being-loaded */
4079                 if (mod->state == MODULE_STATE_COMING)
4080                         buf[bx++] = '+';
4081                 buf[bx++] = ')';
4082         }
4083         buf[bx] = '\0';
4084 
4085         return buf;
4086 }
4087 
4088 #ifdef CONFIG_PROC_FS
4089 /* Called by the /proc file system to return a list of modules. */
4090 static void *m_start(struct seq_file *m, loff_t *pos)
4091 {
4092         mutex_lock(&module_mutex);
4093         return seq_list_start(&modules, *pos);
4094 }
4095 
4096 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4097 {
4098         return seq_list_next(p, &modules, pos);
4099 }
4100 
4101 static void m_stop(struct seq_file *m, void *p)
4102 {
4103         mutex_unlock(&module_mutex);
4104 }
4105 
4106 static int m_show(struct seq_file *m, void *p)
4107 {
4108         struct module *mod = list_entry(p, struct module, list);
4109         char buf[MODULE_FLAGS_BUF_SIZE];
4110 
4111         /* We always ignore unformed modules. */
4112         if (mod->state == MODULE_STATE_UNFORMED)
4113                 return 0;
4114 
4115         seq_printf(m, "%s %u",
4116                    mod->name, mod->init_layout.size + mod->core_layout.size);
4117         print_unload_info(m, mod);
4118 
4119         /* Informative for users. */
4120         seq_printf(m, " %s",
4121                    mod->state == MODULE_STATE_GOING ? "Unloading" :
4122                    mod->state == MODULE_STATE_COMING ? "Loading" :
4123                    "Live");
4124         /* Used by oprofile and other similar tools. */
4125         seq_printf(m, " 0x%pK", mod->core_layout.base);
4126 
4127         /* Taints info */
4128         if (mod->taints)
4129                 seq_printf(m, " %s", module_flags(mod, buf));
4130 
4131         seq_puts(m, "\n");
4132         return 0;
4133 }
4134 
4135 /* Format: modulename size refcount deps address
4136 
4137    Where refcount is a number or -, and deps is a comma-separated list
4138    of depends or -.
4139 */
4140 static const struct seq_operations modules_op = {
4141         .start  = m_start,
4142         .next   = m_next,
4143         .stop   = m_stop,
4144         .show   = m_show
4145 };
4146 
4147 static int modules_open(struct inode *inode, struct file *file)
4148 {
4149         return seq_open(file, &modules_op);
4150 }
4151 
4152 static const struct file_operations proc_modules_operations = {
4153         .open           = modules_open,
4154         .read           = seq_read,
4155         .llseek         = seq_lseek,
4156         .release        = seq_release,
4157 };
4158 
4159 static int __init proc_modules_init(void)
4160 {
4161         proc_create("modules", 0, NULL, &proc_modules_operations);
4162         return 0;
4163 }
4164 module_init(proc_modules_init);
4165 #endif
4166 
4167 /* Given an address, look for it in the module exception tables. */
4168 const struct exception_table_entry *search_module_extables(unsigned long addr)
4169 {
4170         const struct exception_table_entry *e = NULL;
4171         struct module *mod;
4172 
4173         preempt_disable();
4174         list_for_each_entry_rcu(mod, &modules, list) {
4175                 if (mod->state == MODULE_STATE_UNFORMED)
4176                         continue;
4177                 if (mod->num_exentries == 0)
4178                         continue;
4179 
4180                 e = search_extable(mod->extable,
4181                                    mod->extable + mod->num_exentries - 1,
4182                                    addr);
4183                 if (e)
4184                         break;
4185         }
4186         preempt_enable();
4187 
4188         /* Now, if we found one, we are running inside it now, hence
4189            we cannot unload the module, hence no refcnt needed. */
4190         return e;
4191 }
4192 
4193 /*
4194  * is_module_address - is this address inside a module?
4195  * @addr: the address to check.
4196  *
4197  * See is_module_text_address() if you simply want to see if the address
4198  * is code (not data).
4199  */
4200 bool is_module_address(unsigned long addr)
4201 {
4202         bool ret;
4203 
4204         preempt_disable();
4205         ret = __module_address(addr) != NULL;
4206         preempt_enable();
4207 
4208         return ret;
4209 }
4210 
4211 /*
4212  * __module_address - get the module which contains an address.
4213  * @addr: the address.
4214  *
4215  * Must be called with preempt disabled or module mutex held so that
4216  * module doesn't get freed during this.
4217  */
4218 struct module *__module_address(unsigned long addr)
4219 {
4220         struct module *mod;
4221 
4222         if (addr < module_addr_min || addr > module_addr_max)
4223                 return NULL;
4224 
4225         module_assert_mutex_or_preempt();
4226 
4227         mod = mod_find(addr);
4228         if (mod) {
4229                 BUG_ON(!within_module(addr, mod));
4230                 if (mod->state == MODULE_STATE_UNFORMED)
4231                         mod = NULL;
4232         }
4233         return mod;
4234 }
4235 EXPORT_SYMBOL_GPL(__module_address);
4236 
4237 /*
4238  * is_module_text_address - is this address inside module code?
4239  * @addr: the address to check.
4240  *
4241  * See is_module_address() if you simply want to see if the address is
4242  * anywhere in a module.  See kernel_text_address() for testing if an
4243  * address corresponds to kernel or module code.
4244  */
4245 bool is_module_text_address(unsigned long addr)
4246 {
4247         bool ret;
4248 
4249         preempt_disable();
4250         ret = __module_text_address(addr) != NULL;
4251         preempt_enable();
4252 
4253         return ret;
4254 }
4255 
4256 /*
4257  * __module_text_address - get the module whose code contains an address.
4258  * @addr: the address.
4259  *
4260  * Must be called with preempt disabled or module mutex held so that
4261  * module doesn't get freed during this.
4262  */
4263 struct module *__module_text_address(unsigned long addr)
4264 {
4265         struct module *mod = __module_address(addr);
4266         if (mod) {
4267                 /* Make sure it's within the text section. */
4268                 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4269                     && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4270                         mod = NULL;
4271         }
4272         return mod;
4273 }
4274 EXPORT_SYMBOL_GPL(__module_text_address);
4275 
4276 /* Don't grab lock, we're oopsing. */
4277 void print_modules(void)
4278 {
4279         struct module *mod;
4280         char buf[MODULE_FLAGS_BUF_SIZE];
4281 
4282         printk(KERN_DEFAULT "Modules linked in:");
4283         /* Most callers should already have preempt disabled, but make sure */
4284         preempt_disable();
4285         list_for_each_entry_rcu(mod, &modules, list) {
4286                 if (mod->state == MODULE_STATE_UNFORMED)
4287                         continue;
4288                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4289         }
4290         preempt_enable();
4291         if (last_unloaded_module[0])
4292                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4293         pr_cont("\n");
4294 }
4295 
4296 #ifdef CONFIG_MODVERSIONS
4297 /* Generate the signature for all relevant module structures here.
4298  * If these change, we don't want to try to parse the module. */
4299 void module_layout(struct module *mod,
4300                    struct modversion_info *ver,
4301                    struct kernel_param *kp,
4302                    struct kernel_symbol *ks,
4303                    struct tracepoint * const *tp)
4304 {
4305 }
4306 EXPORT_SYMBOL(module_layout);
4307 #endif
4308 

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