Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/kernel/module.c

  1 /*
  2    Copyright (C) 2002 Richard Henderson
  3    Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
  4 
  5     This program is free software; you can redistribute it and/or modify
  6     it under the terms of the GNU General Public License as published by
  7     the Free Software Foundation; either version 2 of the License, or
  8     (at your option) any later version.
  9 
 10     This program is distributed in the hope that it will be useful,
 11     but WITHOUT ANY WARRANTY; without even the implied warranty of
 12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13     GNU General Public License for more details.
 14 
 15     You should have received a copy of the GNU General Public License
 16     along with this program; if not, write to the Free Software
 17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 18 */
 19 #include <linux/export.h>
 20 #include <linux/moduleloader.h>
 21 #include <linux/trace_events.h>
 22 #include <linux/init.h>
 23 #include <linux/kallsyms.h>
 24 #include <linux/file.h>
 25 #include <linux/fs.h>
 26 #include <linux/sysfs.h>
 27 #include <linux/kernel.h>
 28 #include <linux/slab.h>
 29 #include <linux/vmalloc.h>
 30 #include <linux/elf.h>
 31 #include <linux/proc_fs.h>
 32 #include <linux/security.h>
 33 #include <linux/seq_file.h>
 34 #include <linux/syscalls.h>
 35 #include <linux/fcntl.h>
 36 #include <linux/rcupdate.h>
 37 #include <linux/capability.h>
 38 #include <linux/cpu.h>
 39 #include <linux/moduleparam.h>
 40 #include <linux/errno.h>
 41 #include <linux/err.h>
 42 #include <linux/vermagic.h>
 43 #include <linux/notifier.h>
 44 #include <linux/sched.h>
 45 #include <linux/device.h>
 46 #include <linux/string.h>
 47 #include <linux/mutex.h>
 48 #include <linux/rculist.h>
 49 #include <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 
 67 #define CREATE_TRACE_POINTS
 68 #include <trace/events/module.h>
 69 
 70 #ifndef ARCH_SHF_SMALL
 71 #define ARCH_SHF_SMALL 0
 72 #endif
 73 
 74 /*
 75  * Modules' sections will be aligned on page boundaries
 76  * to ensure complete separation of code and data, but
 77  * only when CONFIG_DEBUG_SET_MODULE_RONX=y
 78  */
 79 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 80 # define debug_align(X) ALIGN(X, PAGE_SIZE)
 81 #else
 82 # define debug_align(X) (X)
 83 #endif
 84 
 85 /* If this is set, the section belongs in the init part of the module */
 86 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
 87 
 88 /*
 89  * Mutex protects:
 90  * 1) List of modules (also safely readable with preempt_disable),
 91  * 2) module_use links,
 92  * 3) module_addr_min/module_addr_max.
 93  * (delete and add uses RCU list operations). */
 94 DEFINE_MUTEX(module_mutex);
 95 EXPORT_SYMBOL_GPL(module_mutex);
 96 static LIST_HEAD(modules);
 97 
 98 #ifdef CONFIG_MODULES_TREE_LOOKUP
 99 
100 /*
101  * Use a latched RB-tree for __module_address(); this allows us to use
102  * RCU-sched lookups of the address from any context.
103  *
104  * This is conditional on PERF_EVENTS || TRACING because those can really hit
105  * __module_address() hard by doing a lot of stack unwinding; potentially from
106  * NMI context.
107  */
108 
109 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
110 {
111         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
112 
113         return (unsigned long)layout->base;
114 }
115 
116 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
117 {
118         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
119 
120         return (unsigned long)layout->size;
121 }
122 
123 static __always_inline bool
124 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
125 {
126         return __mod_tree_val(a) < __mod_tree_val(b);
127 }
128 
129 static __always_inline int
130 mod_tree_comp(void *key, struct latch_tree_node *n)
131 {
132         unsigned long val = (unsigned long)key;
133         unsigned long start, end;
134 
135         start = __mod_tree_val(n);
136         if (val < start)
137                 return -1;
138 
139         end = start + __mod_tree_size(n);
140         if (val >= end)
141                 return 1;
142 
143         return 0;
144 }
145 
146 static const struct latch_tree_ops mod_tree_ops = {
147         .less = mod_tree_less,
148         .comp = mod_tree_comp,
149 };
150 
151 static struct mod_tree_root {
152         struct latch_tree_root root;
153         unsigned long addr_min;
154         unsigned long addr_max;
155 } mod_tree __cacheline_aligned = {
156         .addr_min = -1UL,
157 };
158 
159 #define module_addr_min mod_tree.addr_min
160 #define module_addr_max mod_tree.addr_max
161 
162 static noinline void __mod_tree_insert(struct mod_tree_node *node)
163 {
164         latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
165 }
166 
167 static void __mod_tree_remove(struct mod_tree_node *node)
168 {
169         latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
170 }
171 
172 /*
173  * These modifications: insert, remove_init and remove; are serialized by the
174  * module_mutex.
175  */
176 static void mod_tree_insert(struct module *mod)
177 {
178         mod->core_layout.mtn.mod = mod;
179         mod->init_layout.mtn.mod = mod;
180 
181         __mod_tree_insert(&mod->core_layout.mtn);
182         if (mod->init_layout.size)
183                 __mod_tree_insert(&mod->init_layout.mtn);
184 }
185 
186 static void mod_tree_remove_init(struct module *mod)
187 {
188         if (mod->init_layout.size)
189                 __mod_tree_remove(&mod->init_layout.mtn);
190 }
191 
192 static void mod_tree_remove(struct module *mod)
193 {
194         __mod_tree_remove(&mod->core_layout.mtn);
195         mod_tree_remove_init(mod);
196 }
197 
198 static struct module *mod_find(unsigned long addr)
199 {
200         struct latch_tree_node *ltn;
201 
202         ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
203         if (!ltn)
204                 return NULL;
205 
206         return container_of(ltn, struct mod_tree_node, node)->mod;
207 }
208 
209 #else /* MODULES_TREE_LOOKUP */
210 
211 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
212 
213 static void mod_tree_insert(struct module *mod) { }
214 static void mod_tree_remove_init(struct module *mod) { }
215 static void mod_tree_remove(struct module *mod) { }
216 
217 static struct module *mod_find(unsigned long addr)
218 {
219         struct module *mod;
220 
221         list_for_each_entry_rcu(mod, &modules, list) {
222                 if (within_module(addr, mod))
223                         return mod;
224         }
225 
226         return NULL;
227 }
228 
229 #endif /* MODULES_TREE_LOOKUP */
230 
231 /*
232  * Bounds of module text, for speeding up __module_address.
233  * Protected by module_mutex.
234  */
235 static void __mod_update_bounds(void *base, unsigned int size)
236 {
237         unsigned long min = (unsigned long)base;
238         unsigned long max = min + size;
239 
240         if (min < module_addr_min)
241                 module_addr_min = min;
242         if (max > module_addr_max)
243                 module_addr_max = max;
244 }
245 
246 static void mod_update_bounds(struct module *mod)
247 {
248         __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
249         if (mod->init_layout.size)
250                 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
251 }
252 
253 #ifdef CONFIG_KGDB_KDB
254 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
255 #endif /* CONFIG_KGDB_KDB */
256 
257 static void module_assert_mutex(void)
258 {
259         lockdep_assert_held(&module_mutex);
260 }
261 
262 static void module_assert_mutex_or_preempt(void)
263 {
264 #ifdef CONFIG_LOCKDEP
265         if (unlikely(!debug_locks))
266                 return;
267 
268         WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
269                 !lockdep_is_held(&module_mutex));
270 #endif
271 }
272 
273 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
274 #ifndef CONFIG_MODULE_SIG_FORCE
275 module_param(sig_enforce, bool_enable_only, 0644);
276 #endif /* !CONFIG_MODULE_SIG_FORCE */
277 
278 /* Block module loading/unloading? */
279 int modules_disabled = 0;
280 core_param(nomodule, modules_disabled, bint, 0);
281 
282 /* Waiting for a module to finish initializing? */
283 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
284 
285 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
286 
287 int register_module_notifier(struct notifier_block *nb)
288 {
289         return blocking_notifier_chain_register(&module_notify_list, nb);
290 }
291 EXPORT_SYMBOL(register_module_notifier);
292 
293 int unregister_module_notifier(struct notifier_block *nb)
294 {
295         return blocking_notifier_chain_unregister(&module_notify_list, nb);
296 }
297 EXPORT_SYMBOL(unregister_module_notifier);
298 
299 struct load_info {
300         Elf_Ehdr *hdr;
301         unsigned long len;
302         Elf_Shdr *sechdrs;
303         char *secstrings, *strtab;
304         unsigned long symoffs, stroffs;
305         struct _ddebug *debug;
306         unsigned int num_debug;
307         bool sig_ok;
308 #ifdef CONFIG_KALLSYMS
309         unsigned long mod_kallsyms_init_off;
310 #endif
311         struct {
312                 unsigned int sym, str, mod, vers, info, pcpu;
313         } index;
314 };
315 
316 /*
317  * We require a truly strong try_module_get(): 0 means success.
318  * Otherwise an error is returned due to ongoing or failed
319  * initialization etc.
320  */
321 static inline int strong_try_module_get(struct module *mod)
322 {
323         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
324         if (mod && mod->state == MODULE_STATE_COMING)
325                 return -EBUSY;
326         if (try_module_get(mod))
327                 return 0;
328         else
329                 return -ENOENT;
330 }
331 
332 static inline void add_taint_module(struct module *mod, unsigned flag,
333                                     enum lockdep_ok lockdep_ok)
334 {
335         add_taint(flag, lockdep_ok);
336         set_bit(flag, &mod->taints);
337 }
338 
339 /*
340  * A thread that wants to hold a reference to a module only while it
341  * is running can call this to safely exit.  nfsd and lockd use this.
342  */
343 void __noreturn __module_put_and_exit(struct module *mod, long code)
344 {
345         module_put(mod);
346         do_exit(code);
347 }
348 EXPORT_SYMBOL(__module_put_and_exit);
349 
350 /* Find a module section: 0 means not found. */
351 static unsigned int find_sec(const struct load_info *info, const char *name)
352 {
353         unsigned int i;
354 
355         for (i = 1; i < info->hdr->e_shnum; i++) {
356                 Elf_Shdr *shdr = &info->sechdrs[i];
357                 /* Alloc bit cleared means "ignore it." */
358                 if ((shdr->sh_flags & SHF_ALLOC)
359                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
360                         return i;
361         }
362         return 0;
363 }
364 
365 /* Find a module section, or NULL. */
366 static void *section_addr(const struct load_info *info, const char *name)
367 {
368         /* Section 0 has sh_addr 0. */
369         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
370 }
371 
372 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
373 static void *section_objs(const struct load_info *info,
374                           const char *name,
375                           size_t object_size,
376                           unsigned int *num)
377 {
378         unsigned int sec = find_sec(info, name);
379 
380         /* Section 0 has sh_addr 0 and sh_size 0. */
381         *num = info->sechdrs[sec].sh_size / object_size;
382         return (void *)info->sechdrs[sec].sh_addr;
383 }
384 
385 /* Provided by the linker */
386 extern const struct kernel_symbol __start___ksymtab[];
387 extern const struct kernel_symbol __stop___ksymtab[];
388 extern const struct kernel_symbol __start___ksymtab_gpl[];
389 extern const struct kernel_symbol __stop___ksymtab_gpl[];
390 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
391 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
392 extern const s32 __start___kcrctab[];
393 extern const s32 __start___kcrctab_gpl[];
394 extern const s32 __start___kcrctab_gpl_future[];
395 #ifdef CONFIG_UNUSED_SYMBOLS
396 extern const struct kernel_symbol __start___ksymtab_unused[];
397 extern const struct kernel_symbol __stop___ksymtab_unused[];
398 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
399 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
400 extern const s32 __start___kcrctab_unused[];
401 extern const s32 __start___kcrctab_unused_gpl[];
402 #endif
403 
404 #ifndef CONFIG_MODVERSIONS
405 #define symversion(base, idx) NULL
406 #else
407 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
408 #endif
409 
410 static bool each_symbol_in_section(const struct symsearch *arr,
411                                    unsigned int arrsize,
412                                    struct module *owner,
413                                    bool (*fn)(const struct symsearch *syms,
414                                               struct module *owner,
415                                               void *data),
416                                    void *data)
417 {
418         unsigned int j;
419 
420         for (j = 0; j < arrsize; j++) {
421                 if (fn(&arr[j], owner, data))
422                         return true;
423         }
424 
425         return false;
426 }
427 
428 /* Returns true as soon as fn returns true, otherwise false. */
429 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
430                                     struct module *owner,
431                                     void *data),
432                          void *data)
433 {
434         struct module *mod;
435         static const struct symsearch arr[] = {
436                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
437                   NOT_GPL_ONLY, false },
438                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
439                   __start___kcrctab_gpl,
440                   GPL_ONLY, false },
441                 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
442                   __start___kcrctab_gpl_future,
443                   WILL_BE_GPL_ONLY, false },
444 #ifdef CONFIG_UNUSED_SYMBOLS
445                 { __start___ksymtab_unused, __stop___ksymtab_unused,
446                   __start___kcrctab_unused,
447                   NOT_GPL_ONLY, true },
448                 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
449                   __start___kcrctab_unused_gpl,
450                   GPL_ONLY, true },
451 #endif
452         };
453 
454         module_assert_mutex_or_preempt();
455 
456         if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
457                 return true;
458 
459         list_for_each_entry_rcu(mod, &modules, list) {
460                 struct symsearch arr[] = {
461                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
462                           NOT_GPL_ONLY, false },
463                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
464                           mod->gpl_crcs,
465                           GPL_ONLY, false },
466                         { mod->gpl_future_syms,
467                           mod->gpl_future_syms + mod->num_gpl_future_syms,
468                           mod->gpl_future_crcs,
469                           WILL_BE_GPL_ONLY, false },
470 #ifdef CONFIG_UNUSED_SYMBOLS
471                         { mod->unused_syms,
472                           mod->unused_syms + mod->num_unused_syms,
473                           mod->unused_crcs,
474                           NOT_GPL_ONLY, true },
475                         { mod->unused_gpl_syms,
476                           mod->unused_gpl_syms + mod->num_unused_gpl_syms,
477                           mod->unused_gpl_crcs,
478                           GPL_ONLY, true },
479 #endif
480                 };
481 
482                 if (mod->state == MODULE_STATE_UNFORMED)
483                         continue;
484 
485                 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
486                         return true;
487         }
488         return false;
489 }
490 EXPORT_SYMBOL_GPL(each_symbol_section);
491 
492 struct find_symbol_arg {
493         /* Input */
494         const char *name;
495         bool gplok;
496         bool warn;
497 
498         /* Output */
499         struct module *owner;
500         const s32 *crc;
501         const struct kernel_symbol *sym;
502 };
503 
504 static bool check_symbol(const struct symsearch *syms,
505                                  struct module *owner,
506                                  unsigned int symnum, void *data)
507 {
508         struct find_symbol_arg *fsa = data;
509 
510         if (!fsa->gplok) {
511                 if (syms->licence == GPL_ONLY)
512                         return false;
513                 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
514                         pr_warn("Symbol %s is being used by a non-GPL module, "
515                                 "which will not be allowed in the future\n",
516                                 fsa->name);
517                 }
518         }
519 
520 #ifdef CONFIG_UNUSED_SYMBOLS
521         if (syms->unused && fsa->warn) {
522                 pr_warn("Symbol %s is marked as UNUSED, however this module is "
523                         "using it.\n", fsa->name);
524                 pr_warn("This symbol will go away in the future.\n");
525                 pr_warn("Please evaluate if this is the right api to use and "
526                         "if it really is, submit a report to the linux kernel "
527                         "mailing list together with submitting your code for "
528                         "inclusion.\n");
529         }
530 #endif
531 
532         fsa->owner = owner;
533         fsa->crc = symversion(syms->crcs, symnum);
534         fsa->sym = &syms->start[symnum];
535         return true;
536 }
537 
538 static int cmp_name(const void *va, const void *vb)
539 {
540         const char *a;
541         const struct kernel_symbol *b;
542         a = va; b = vb;
543         return strcmp(a, b->name);
544 }
545 
546 static bool find_symbol_in_section(const struct symsearch *syms,
547                                    struct module *owner,
548                                    void *data)
549 {
550         struct find_symbol_arg *fsa = data;
551         struct kernel_symbol *sym;
552 
553         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
554                         sizeof(struct kernel_symbol), cmp_name);
555 
556         if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
557                 return true;
558 
559         return false;
560 }
561 
562 /* Find a symbol and return it, along with, (optional) crc and
563  * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
564 const struct kernel_symbol *find_symbol(const char *name,
565                                         struct module **owner,
566                                         const s32 **crc,
567                                         bool gplok,
568                                         bool warn)
569 {
570         struct find_symbol_arg fsa;
571 
572         fsa.name = name;
573         fsa.gplok = gplok;
574         fsa.warn = warn;
575 
576         if (each_symbol_section(find_symbol_in_section, &fsa)) {
577                 if (owner)
578                         *owner = fsa.owner;
579                 if (crc)
580                         *crc = fsa.crc;
581                 return fsa.sym;
582         }
583 
584         pr_debug("Failed to find symbol %s\n", name);
585         return NULL;
586 }
587 EXPORT_SYMBOL_GPL(find_symbol);
588 
589 /*
590  * Search for module by name: must hold module_mutex (or preempt disabled
591  * for read-only access).
592  */
593 static struct module *find_module_all(const char *name, size_t len,
594                                       bool even_unformed)
595 {
596         struct module *mod;
597 
598         module_assert_mutex_or_preempt();
599 
600         list_for_each_entry(mod, &modules, list) {
601                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
602                         continue;
603                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
604                         return mod;
605         }
606         return NULL;
607 }
608 
609 struct module *find_module(const char *name)
610 {
611         module_assert_mutex();
612         return find_module_all(name, strlen(name), false);
613 }
614 EXPORT_SYMBOL_GPL(find_module);
615 
616 #ifdef CONFIG_SMP
617 
618 static inline void __percpu *mod_percpu(struct module *mod)
619 {
620         return mod->percpu;
621 }
622 
623 static int percpu_modalloc(struct module *mod, struct load_info *info)
624 {
625         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
626         unsigned long align = pcpusec->sh_addralign;
627 
628         if (!pcpusec->sh_size)
629                 return 0;
630 
631         if (align > PAGE_SIZE) {
632                 pr_warn("%s: per-cpu alignment %li > %li\n",
633                         mod->name, align, PAGE_SIZE);
634                 align = PAGE_SIZE;
635         }
636 
637         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
638         if (!mod->percpu) {
639                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
640                         mod->name, (unsigned long)pcpusec->sh_size);
641                 return -ENOMEM;
642         }
643         mod->percpu_size = pcpusec->sh_size;
644         return 0;
645 }
646 
647 static void percpu_modfree(struct module *mod)
648 {
649         free_percpu(mod->percpu);
650 }
651 
652 static unsigned int find_pcpusec(struct load_info *info)
653 {
654         return find_sec(info, ".data..percpu");
655 }
656 
657 static void percpu_modcopy(struct module *mod,
658                            const void *from, unsigned long size)
659 {
660         int cpu;
661 
662         for_each_possible_cpu(cpu)
663                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
664 }
665 
666 /**
667  * is_module_percpu_address - test whether address is from module static percpu
668  * @addr: address to test
669  *
670  * Test whether @addr belongs to module static percpu area.
671  *
672  * RETURNS:
673  * %true if @addr is from module static percpu area
674  */
675 bool is_module_percpu_address(unsigned long addr)
676 {
677         struct module *mod;
678         unsigned int cpu;
679 
680         preempt_disable();
681 
682         list_for_each_entry_rcu(mod, &modules, list) {
683                 if (mod->state == MODULE_STATE_UNFORMED)
684                         continue;
685                 if (!mod->percpu_size)
686                         continue;
687                 for_each_possible_cpu(cpu) {
688                         void *start = per_cpu_ptr(mod->percpu, cpu);
689 
690                         if ((void *)addr >= start &&
691                             (void *)addr < start + mod->percpu_size) {
692                                 preempt_enable();
693                                 return true;
694                         }
695                 }
696         }
697 
698         preempt_enable();
699         return false;
700 }
701 
702 #else /* ... !CONFIG_SMP */
703 
704 static inline void __percpu *mod_percpu(struct module *mod)
705 {
706         return NULL;
707 }
708 static int percpu_modalloc(struct module *mod, struct load_info *info)
709 {
710         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
711         if (info->sechdrs[info->index.pcpu].sh_size != 0)
712                 return -ENOMEM;
713         return 0;
714 }
715 static inline void percpu_modfree(struct module *mod)
716 {
717 }
718 static unsigned int find_pcpusec(struct load_info *info)
719 {
720         return 0;
721 }
722 static inline void percpu_modcopy(struct module *mod,
723                                   const void *from, unsigned long size)
724 {
725         /* pcpusec should be 0, and size of that section should be 0. */
726         BUG_ON(size != 0);
727 }
728 bool is_module_percpu_address(unsigned long addr)
729 {
730         return false;
731 }
732 
733 #endif /* CONFIG_SMP */
734 
735 #define MODINFO_ATTR(field)     \
736 static void setup_modinfo_##field(struct module *mod, const char *s)  \
737 {                                                                     \
738         mod->field = kstrdup(s, GFP_KERNEL);                          \
739 }                                                                     \
740 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
741                         struct module_kobject *mk, char *buffer)      \
742 {                                                                     \
743         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
744 }                                                                     \
745 static int modinfo_##field##_exists(struct module *mod)               \
746 {                                                                     \
747         return mod->field != NULL;                                    \
748 }                                                                     \
749 static void free_modinfo_##field(struct module *mod)                  \
750 {                                                                     \
751         kfree(mod->field);                                            \
752         mod->field = NULL;                                            \
753 }                                                                     \
754 static struct module_attribute modinfo_##field = {                    \
755         .attr = { .name = __stringify(field), .mode = 0444 },         \
756         .show = show_modinfo_##field,                                 \
757         .setup = setup_modinfo_##field,                               \
758         .test = modinfo_##field##_exists,                             \
759         .free = free_modinfo_##field,                                 \
760 };
761 
762 MODINFO_ATTR(version);
763 MODINFO_ATTR(srcversion);
764 
765 static char last_unloaded_module[MODULE_NAME_LEN+1];
766 
767 #ifdef CONFIG_MODULE_UNLOAD
768 
769 EXPORT_TRACEPOINT_SYMBOL(module_get);
770 
771 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
772 #define MODULE_REF_BASE 1
773 
774 /* Init the unload section of the module. */
775 static int module_unload_init(struct module *mod)
776 {
777         /*
778          * Initialize reference counter to MODULE_REF_BASE.
779          * refcnt == 0 means module is going.
780          */
781         atomic_set(&mod->refcnt, MODULE_REF_BASE);
782 
783         INIT_LIST_HEAD(&mod->source_list);
784         INIT_LIST_HEAD(&mod->target_list);
785 
786         /* Hold reference count during initialization. */
787         atomic_inc(&mod->refcnt);
788 
789         return 0;
790 }
791 
792 /* Does a already use b? */
793 static int already_uses(struct module *a, struct module *b)
794 {
795         struct module_use *use;
796 
797         list_for_each_entry(use, &b->source_list, source_list) {
798                 if (use->source == a) {
799                         pr_debug("%s uses %s!\n", a->name, b->name);
800                         return 1;
801                 }
802         }
803         pr_debug("%s does not use %s!\n", a->name, b->name);
804         return 0;
805 }
806 
807 /*
808  * Module a uses b
809  *  - we add 'a' as a "source", 'b' as a "target" of module use
810  *  - the module_use is added to the list of 'b' sources (so
811  *    'b' can walk the list to see who sourced them), and of 'a'
812  *    targets (so 'a' can see what modules it targets).
813  */
814 static int add_module_usage(struct module *a, struct module *b)
815 {
816         struct module_use *use;
817 
818         pr_debug("Allocating new usage for %s.\n", a->name);
819         use = kmalloc(sizeof(*use), GFP_ATOMIC);
820         if (!use) {
821                 pr_warn("%s: out of memory loading\n", a->name);
822                 return -ENOMEM;
823         }
824 
825         use->source = a;
826         use->target = b;
827         list_add(&use->source_list, &b->source_list);
828         list_add(&use->target_list, &a->target_list);
829         return 0;
830 }
831 
832 /* Module a uses b: caller needs module_mutex() */
833 int ref_module(struct module *a, struct module *b)
834 {
835         int err;
836 
837         if (b == NULL || already_uses(a, b))
838                 return 0;
839 
840         /* If module isn't available, we fail. */
841         err = strong_try_module_get(b);
842         if (err)
843                 return err;
844 
845         err = add_module_usage(a, b);
846         if (err) {
847                 module_put(b);
848                 return err;
849         }
850         return 0;
851 }
852 EXPORT_SYMBOL_GPL(ref_module);
853 
854 /* Clear the unload stuff of the module. */
855 static void module_unload_free(struct module *mod)
856 {
857         struct module_use *use, *tmp;
858 
859         mutex_lock(&module_mutex);
860         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
861                 struct module *i = use->target;
862                 pr_debug("%s unusing %s\n", mod->name, i->name);
863                 module_put(i);
864                 list_del(&use->source_list);
865                 list_del(&use->target_list);
866                 kfree(use);
867         }
868         mutex_unlock(&module_mutex);
869 }
870 
871 #ifdef CONFIG_MODULE_FORCE_UNLOAD
872 static inline int try_force_unload(unsigned int flags)
873 {
874         int ret = (flags & O_TRUNC);
875         if (ret)
876                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
877         return ret;
878 }
879 #else
880 static inline int try_force_unload(unsigned int flags)
881 {
882         return 0;
883 }
884 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
885 
886 /* Try to release refcount of module, 0 means success. */
887 static int try_release_module_ref(struct module *mod)
888 {
889         int ret;
890 
891         /* Try to decrement refcnt which we set at loading */
892         ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
893         BUG_ON(ret < 0);
894         if (ret)
895                 /* Someone can put this right now, recover with checking */
896                 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
897 
898         return ret;
899 }
900 
901 static int try_stop_module(struct module *mod, int flags, int *forced)
902 {
903         /* If it's not unused, quit unless we're forcing. */
904         if (try_release_module_ref(mod) != 0) {
905                 *forced = try_force_unload(flags);
906                 if (!(*forced))
907                         return -EWOULDBLOCK;
908         }
909 
910         /* Mark it as dying. */
911         mod->state = MODULE_STATE_GOING;
912 
913         return 0;
914 }
915 
916 /**
917  * module_refcount - return the refcount or -1 if unloading
918  *
919  * @mod:        the module we're checking
920  *
921  * Returns:
922  *      -1 if the module is in the process of unloading
923  *      otherwise the number of references in the kernel to the module
924  */
925 int module_refcount(struct module *mod)
926 {
927         return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
928 }
929 EXPORT_SYMBOL(module_refcount);
930 
931 /* This exists whether we can unload or not */
932 static void free_module(struct module *mod);
933 
934 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
935                 unsigned int, flags)
936 {
937         struct module *mod;
938         char name[MODULE_NAME_LEN];
939         int ret, forced = 0;
940 
941         if (!capable(CAP_SYS_MODULE) || modules_disabled)
942                 return -EPERM;
943 
944         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
945                 return -EFAULT;
946         name[MODULE_NAME_LEN-1] = '\0';
947 
948         if (mutex_lock_interruptible(&module_mutex) != 0)
949                 return -EINTR;
950 
951         mod = find_module(name);
952         if (!mod) {
953                 ret = -ENOENT;
954                 goto out;
955         }
956 
957         if (!list_empty(&mod->source_list)) {
958                 /* Other modules depend on us: get rid of them first. */
959                 ret = -EWOULDBLOCK;
960                 goto out;
961         }
962 
963         /* Doing init or already dying? */
964         if (mod->state != MODULE_STATE_LIVE) {
965                 /* FIXME: if (force), slam module count damn the torpedoes */
966                 pr_debug("%s already dying\n", mod->name);
967                 ret = -EBUSY;
968                 goto out;
969         }
970 
971         /* If it has an init func, it must have an exit func to unload */
972         if (mod->init && !mod->exit) {
973                 forced = try_force_unload(flags);
974                 if (!forced) {
975                         /* This module can't be removed */
976                         ret = -EBUSY;
977                         goto out;
978                 }
979         }
980 
981         /* Stop the machine so refcounts can't move and disable module. */
982         ret = try_stop_module(mod, flags, &forced);
983         if (ret != 0)
984                 goto out;
985 
986         mutex_unlock(&module_mutex);
987         /* Final destruction now no one is using it. */
988         if (mod->exit != NULL)
989                 mod->exit();
990         blocking_notifier_call_chain(&module_notify_list,
991                                      MODULE_STATE_GOING, mod);
992         klp_module_going(mod);
993         ftrace_release_mod(mod);
994 
995         async_synchronize_full();
996 
997         /* Store the name of the last unloaded module for diagnostic purposes */
998         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
999 
1000         free_module(mod);
1001         return 0;
1002 out:
1003         mutex_unlock(&module_mutex);
1004         return ret;
1005 }
1006 
1007 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1008 {
1009         struct module_use *use;
1010         int printed_something = 0;
1011 
1012         seq_printf(m, " %i ", module_refcount(mod));
1013 
1014         /*
1015          * Always include a trailing , so userspace can differentiate
1016          * between this and the old multi-field proc format.
1017          */
1018         list_for_each_entry(use, &mod->source_list, source_list) {
1019                 printed_something = 1;
1020                 seq_printf(m, "%s,", use->source->name);
1021         }
1022 
1023         if (mod->init != NULL && mod->exit == NULL) {
1024                 printed_something = 1;
1025                 seq_puts(m, "[permanent],");
1026         }
1027 
1028         if (!printed_something)
1029                 seq_puts(m, "-");
1030 }
1031 
1032 void __symbol_put(const char *symbol)
1033 {
1034         struct module *owner;
1035 
1036         preempt_disable();
1037         if (!find_symbol(symbol, &owner, NULL, true, false))
1038                 BUG();
1039         module_put(owner);
1040         preempt_enable();
1041 }
1042 EXPORT_SYMBOL(__symbol_put);
1043 
1044 /* Note this assumes addr is a function, which it currently always is. */
1045 void symbol_put_addr(void *addr)
1046 {
1047         struct module *modaddr;
1048         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1049 
1050         if (core_kernel_text(a))
1051                 return;
1052 
1053         /*
1054          * Even though we hold a reference on the module; we still need to
1055          * disable preemption in order to safely traverse the data structure.
1056          */
1057         preempt_disable();
1058         modaddr = __module_text_address(a);
1059         BUG_ON(!modaddr);
1060         module_put(modaddr);
1061         preempt_enable();
1062 }
1063 EXPORT_SYMBOL_GPL(symbol_put_addr);
1064 
1065 static ssize_t show_refcnt(struct module_attribute *mattr,
1066                            struct module_kobject *mk, char *buffer)
1067 {
1068         return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1069 }
1070 
1071 static struct module_attribute modinfo_refcnt =
1072         __ATTR(refcnt, 0444, show_refcnt, NULL);
1073 
1074 void __module_get(struct module *module)
1075 {
1076         if (module) {
1077                 preempt_disable();
1078                 atomic_inc(&module->refcnt);
1079                 trace_module_get(module, _RET_IP_);
1080                 preempt_enable();
1081         }
1082 }
1083 EXPORT_SYMBOL(__module_get);
1084 
1085 bool try_module_get(struct module *module)
1086 {
1087         bool ret = true;
1088 
1089         if (module) {
1090                 preempt_disable();
1091                 /* Note: here, we can fail to get a reference */
1092                 if (likely(module_is_live(module) &&
1093                            atomic_inc_not_zero(&module->refcnt) != 0))
1094                         trace_module_get(module, _RET_IP_);
1095                 else
1096                         ret = false;
1097 
1098                 preempt_enable();
1099         }
1100         return ret;
1101 }
1102 EXPORT_SYMBOL(try_module_get);
1103 
1104 void module_put(struct module *module)
1105 {
1106         int ret;
1107 
1108         if (module) {
1109                 preempt_disable();
1110                 ret = atomic_dec_if_positive(&module->refcnt);
1111                 WARN_ON(ret < 0);       /* Failed to put refcount */
1112                 trace_module_put(module, _RET_IP_);
1113                 preempt_enable();
1114         }
1115 }
1116 EXPORT_SYMBOL(module_put);
1117 
1118 #else /* !CONFIG_MODULE_UNLOAD */
1119 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1120 {
1121         /* We don't know the usage count, or what modules are using. */
1122         seq_puts(m, " - -");
1123 }
1124 
1125 static inline void module_unload_free(struct module *mod)
1126 {
1127 }
1128 
1129 int ref_module(struct module *a, struct module *b)
1130 {
1131         return strong_try_module_get(b);
1132 }
1133 EXPORT_SYMBOL_GPL(ref_module);
1134 
1135 static inline int module_unload_init(struct module *mod)
1136 {
1137         return 0;
1138 }
1139 #endif /* CONFIG_MODULE_UNLOAD */
1140 
1141 static size_t module_flags_taint(struct module *mod, char *buf)
1142 {
1143         size_t l = 0;
1144         int i;
1145 
1146         for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1147                 if (taint_flags[i].module && test_bit(i, &mod->taints))
1148                         buf[l++] = taint_flags[i].c_true;
1149         }
1150 
1151         return l;
1152 }
1153 
1154 static ssize_t show_initstate(struct module_attribute *mattr,
1155                               struct module_kobject *mk, char *buffer)
1156 {
1157         const char *state = "unknown";
1158 
1159         switch (mk->mod->state) {
1160         case MODULE_STATE_LIVE:
1161                 state = "live";
1162                 break;
1163         case MODULE_STATE_COMING:
1164                 state = "coming";
1165                 break;
1166         case MODULE_STATE_GOING:
1167                 state = "going";
1168                 break;
1169         default:
1170                 BUG();
1171         }
1172         return sprintf(buffer, "%s\n", state);
1173 }
1174 
1175 static struct module_attribute modinfo_initstate =
1176         __ATTR(initstate, 0444, show_initstate, NULL);
1177 
1178 static ssize_t store_uevent(struct module_attribute *mattr,
1179                             struct module_kobject *mk,
1180                             const char *buffer, size_t count)
1181 {
1182         enum kobject_action action;
1183 
1184         if (kobject_action_type(buffer, count, &action) == 0)
1185                 kobject_uevent(&mk->kobj, action);
1186         return count;
1187 }
1188 
1189 struct module_attribute module_uevent =
1190         __ATTR(uevent, 0200, NULL, store_uevent);
1191 
1192 static ssize_t show_coresize(struct module_attribute *mattr,
1193                              struct module_kobject *mk, char *buffer)
1194 {
1195         return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1196 }
1197 
1198 static struct module_attribute modinfo_coresize =
1199         __ATTR(coresize, 0444, show_coresize, NULL);
1200 
1201 static ssize_t show_initsize(struct module_attribute *mattr,
1202                              struct module_kobject *mk, char *buffer)
1203 {
1204         return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1205 }
1206 
1207 static struct module_attribute modinfo_initsize =
1208         __ATTR(initsize, 0444, show_initsize, NULL);
1209 
1210 static ssize_t show_taint(struct module_attribute *mattr,
1211                           struct module_kobject *mk, char *buffer)
1212 {
1213         size_t l;
1214 
1215         l = module_flags_taint(mk->mod, buffer);
1216         buffer[l++] = '\n';
1217         return l;
1218 }
1219 
1220 static struct module_attribute modinfo_taint =
1221         __ATTR(taint, 0444, show_taint, NULL);
1222 
1223 static struct module_attribute *modinfo_attrs[] = {
1224         &module_uevent,
1225         &modinfo_version,
1226         &modinfo_srcversion,
1227         &modinfo_initstate,
1228         &modinfo_coresize,
1229         &modinfo_initsize,
1230         &modinfo_taint,
1231 #ifdef CONFIG_MODULE_UNLOAD
1232         &modinfo_refcnt,
1233 #endif
1234         NULL,
1235 };
1236 
1237 static const char vermagic[] = VERMAGIC_STRING;
1238 
1239 static int try_to_force_load(struct module *mod, const char *reason)
1240 {
1241 #ifdef CONFIG_MODULE_FORCE_LOAD
1242         if (!test_taint(TAINT_FORCED_MODULE))
1243                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1244         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1245         return 0;
1246 #else
1247         return -ENOEXEC;
1248 #endif
1249 }
1250 
1251 #ifdef CONFIG_MODVERSIONS
1252 
1253 static u32 resolve_rel_crc(const s32 *crc)
1254 {
1255         return *(u32 *)((void *)crc + *crc);
1256 }
1257 
1258 static int check_version(Elf_Shdr *sechdrs,
1259                          unsigned int versindex,
1260                          const char *symname,
1261                          struct module *mod,
1262                          const s32 *crc)
1263 {
1264         unsigned int i, num_versions;
1265         struct modversion_info *versions;
1266 
1267         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1268         if (!crc)
1269                 return 1;
1270 
1271         /* No versions at all?  modprobe --force does this. */
1272         if (versindex == 0)
1273                 return try_to_force_load(mod, symname) == 0;
1274 
1275         versions = (void *) sechdrs[versindex].sh_addr;
1276         num_versions = sechdrs[versindex].sh_size
1277                 / sizeof(struct modversion_info);
1278 
1279         for (i = 0; i < num_versions; i++) {
1280                 u32 crcval;
1281 
1282                 if (strcmp(versions[i].name, symname) != 0)
1283                         continue;
1284 
1285                 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1286                         crcval = resolve_rel_crc(crc);
1287                 else
1288                         crcval = *crc;
1289                 if (versions[i].crc == crcval)
1290                         return 1;
1291                 pr_debug("Found checksum %X vs module %lX\n",
1292                          crcval, versions[i].crc);
1293                 goto bad_version;
1294         }
1295 
1296         /* Broken toolchain. Warn once, then let it go.. */
1297         pr_warn_once("%s: no symbol version for %s\n", mod->name, symname);
1298         return 1;
1299 
1300 bad_version:
1301         pr_warn("%s: disagrees about version of symbol %s\n",
1302                mod->name, symname);
1303         return 0;
1304 }
1305 
1306 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1307                                           unsigned int versindex,
1308                                           struct module *mod)
1309 {
1310         const s32 *crc;
1311 
1312         /*
1313          * Since this should be found in kernel (which can't be removed), no
1314          * locking is necessary -- use preempt_disable() to placate lockdep.
1315          */
1316         preempt_disable();
1317         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1318                          &crc, true, false)) {
1319                 preempt_enable();
1320                 BUG();
1321         }
1322         preempt_enable();
1323         return check_version(sechdrs, versindex,
1324                              VMLINUX_SYMBOL_STR(module_layout), mod, crc);
1325 }
1326 
1327 /* First part is kernel version, which we ignore if module has crcs. */
1328 static inline int same_magic(const char *amagic, const char *bmagic,
1329                              bool has_crcs)
1330 {
1331         if (has_crcs) {
1332                 amagic += strcspn(amagic, " ");
1333                 bmagic += strcspn(bmagic, " ");
1334         }
1335         return strcmp(amagic, bmagic) == 0;
1336 }
1337 #else
1338 static inline int check_version(Elf_Shdr *sechdrs,
1339                                 unsigned int versindex,
1340                                 const char *symname,
1341                                 struct module *mod,
1342                                 const s32 *crc)
1343 {
1344         return 1;
1345 }
1346 
1347 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1348                                           unsigned int versindex,
1349                                           struct module *mod)
1350 {
1351         return 1;
1352 }
1353 
1354 static inline int same_magic(const char *amagic, const char *bmagic,
1355                              bool has_crcs)
1356 {
1357         return strcmp(amagic, bmagic) == 0;
1358 }
1359 #endif /* CONFIG_MODVERSIONS */
1360 
1361 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1362 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1363                                                   const struct load_info *info,
1364                                                   const char *name,
1365                                                   char ownername[])
1366 {
1367         struct module *owner;
1368         const struct kernel_symbol *sym;
1369         const s32 *crc;
1370         int err;
1371 
1372         /*
1373          * The module_mutex should not be a heavily contended lock;
1374          * if we get the occasional sleep here, we'll go an extra iteration
1375          * in the wait_event_interruptible(), which is harmless.
1376          */
1377         sched_annotate_sleep();
1378         mutex_lock(&module_mutex);
1379         sym = find_symbol(name, &owner, &crc,
1380                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1381         if (!sym)
1382                 goto unlock;
1383 
1384         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc)) {
1385                 sym = ERR_PTR(-EINVAL);
1386                 goto getname;
1387         }
1388 
1389         err = ref_module(mod, owner);
1390         if (err) {
1391                 sym = ERR_PTR(err);
1392                 goto getname;
1393         }
1394 
1395 getname:
1396         /* We must make copy under the lock if we failed to get ref. */
1397         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1398 unlock:
1399         mutex_unlock(&module_mutex);
1400         return sym;
1401 }
1402 
1403 static const struct kernel_symbol *
1404 resolve_symbol_wait(struct module *mod,
1405                     const struct load_info *info,
1406                     const char *name)
1407 {
1408         const struct kernel_symbol *ksym;
1409         char owner[MODULE_NAME_LEN];
1410 
1411         if (wait_event_interruptible_timeout(module_wq,
1412                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1413                         || PTR_ERR(ksym) != -EBUSY,
1414                                              30 * HZ) <= 0) {
1415                 pr_warn("%s: gave up waiting for init of module %s.\n",
1416                         mod->name, owner);
1417         }
1418         return ksym;
1419 }
1420 
1421 /*
1422  * /sys/module/foo/sections stuff
1423  * J. Corbet <corbet@lwn.net>
1424  */
1425 #ifdef CONFIG_SYSFS
1426 
1427 #ifdef CONFIG_KALLSYMS
1428 static inline bool sect_empty(const Elf_Shdr *sect)
1429 {
1430         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1431 }
1432 
1433 struct module_sect_attr {
1434         struct module_attribute mattr;
1435         char *name;
1436         unsigned long address;
1437 };
1438 
1439 struct module_sect_attrs {
1440         struct attribute_group grp;
1441         unsigned int nsections;
1442         struct module_sect_attr attrs[0];
1443 };
1444 
1445 static ssize_t module_sect_show(struct module_attribute *mattr,
1446                                 struct module_kobject *mk, char *buf)
1447 {
1448         struct module_sect_attr *sattr =
1449                 container_of(mattr, struct module_sect_attr, mattr);
1450         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1451 }
1452 
1453 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1454 {
1455         unsigned int section;
1456 
1457         for (section = 0; section < sect_attrs->nsections; section++)
1458                 kfree(sect_attrs->attrs[section].name);
1459         kfree(sect_attrs);
1460 }
1461 
1462 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1463 {
1464         unsigned int nloaded = 0, i, size[2];
1465         struct module_sect_attrs *sect_attrs;
1466         struct module_sect_attr *sattr;
1467         struct attribute **gattr;
1468 
1469         /* Count loaded sections and allocate structures */
1470         for (i = 0; i < info->hdr->e_shnum; i++)
1471                 if (!sect_empty(&info->sechdrs[i]))
1472                         nloaded++;
1473         size[0] = ALIGN(sizeof(*sect_attrs)
1474                         + nloaded * sizeof(sect_attrs->attrs[0]),
1475                         sizeof(sect_attrs->grp.attrs[0]));
1476         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1477         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1478         if (sect_attrs == NULL)
1479                 return;
1480 
1481         /* Setup section attributes. */
1482         sect_attrs->grp.name = "sections";
1483         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1484 
1485         sect_attrs->nsections = 0;
1486         sattr = &sect_attrs->attrs[0];
1487         gattr = &sect_attrs->grp.attrs[0];
1488         for (i = 0; i < info->hdr->e_shnum; i++) {
1489                 Elf_Shdr *sec = &info->sechdrs[i];
1490                 if (sect_empty(sec))
1491                         continue;
1492                 sattr->address = sec->sh_addr;
1493                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1494                                         GFP_KERNEL);
1495                 if (sattr->name == NULL)
1496                         goto out;
1497                 sect_attrs->nsections++;
1498                 sysfs_attr_init(&sattr->mattr.attr);
1499                 sattr->mattr.show = module_sect_show;
1500                 sattr->mattr.store = NULL;
1501                 sattr->mattr.attr.name = sattr->name;
1502                 sattr->mattr.attr.mode = S_IRUGO;
1503                 *(gattr++) = &(sattr++)->mattr.attr;
1504         }
1505         *gattr = NULL;
1506 
1507         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1508                 goto out;
1509 
1510         mod->sect_attrs = sect_attrs;
1511         return;
1512   out:
1513         free_sect_attrs(sect_attrs);
1514 }
1515 
1516 static void remove_sect_attrs(struct module *mod)
1517 {
1518         if (mod->sect_attrs) {
1519                 sysfs_remove_group(&mod->mkobj.kobj,
1520                                    &mod->sect_attrs->grp);
1521                 /* We are positive that no one is using any sect attrs
1522                  * at this point.  Deallocate immediately. */
1523                 free_sect_attrs(mod->sect_attrs);
1524                 mod->sect_attrs = NULL;
1525         }
1526 }
1527 
1528 /*
1529  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1530  */
1531 
1532 struct module_notes_attrs {
1533         struct kobject *dir;
1534         unsigned int notes;
1535         struct bin_attribute attrs[0];
1536 };
1537 
1538 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1539                                  struct bin_attribute *bin_attr,
1540                                  char *buf, loff_t pos, size_t count)
1541 {
1542         /*
1543          * The caller checked the pos and count against our size.
1544          */
1545         memcpy(buf, bin_attr->private + pos, count);
1546         return count;
1547 }
1548 
1549 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1550                              unsigned int i)
1551 {
1552         if (notes_attrs->dir) {
1553                 while (i-- > 0)
1554                         sysfs_remove_bin_file(notes_attrs->dir,
1555                                               &notes_attrs->attrs[i]);
1556                 kobject_put(notes_attrs->dir);
1557         }
1558         kfree(notes_attrs);
1559 }
1560 
1561 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1562 {
1563         unsigned int notes, loaded, i;
1564         struct module_notes_attrs *notes_attrs;
1565         struct bin_attribute *nattr;
1566 
1567         /* failed to create section attributes, so can't create notes */
1568         if (!mod->sect_attrs)
1569                 return;
1570 
1571         /* Count notes sections and allocate structures.  */
1572         notes = 0;
1573         for (i = 0; i < info->hdr->e_shnum; i++)
1574                 if (!sect_empty(&info->sechdrs[i]) &&
1575                     (info->sechdrs[i].sh_type == SHT_NOTE))
1576                         ++notes;
1577 
1578         if (notes == 0)
1579                 return;
1580 
1581         notes_attrs = kzalloc(sizeof(*notes_attrs)
1582                               + notes * sizeof(notes_attrs->attrs[0]),
1583                               GFP_KERNEL);
1584         if (notes_attrs == NULL)
1585                 return;
1586 
1587         notes_attrs->notes = notes;
1588         nattr = &notes_attrs->attrs[0];
1589         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1590                 if (sect_empty(&info->sechdrs[i]))
1591                         continue;
1592                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1593                         sysfs_bin_attr_init(nattr);
1594                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1595                         nattr->attr.mode = S_IRUGO;
1596                         nattr->size = info->sechdrs[i].sh_size;
1597                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1598                         nattr->read = module_notes_read;
1599                         ++nattr;
1600                 }
1601                 ++loaded;
1602         }
1603 
1604         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1605         if (!notes_attrs->dir)
1606                 goto out;
1607 
1608         for (i = 0; i < notes; ++i)
1609                 if (sysfs_create_bin_file(notes_attrs->dir,
1610                                           &notes_attrs->attrs[i]))
1611                         goto out;
1612 
1613         mod->notes_attrs = notes_attrs;
1614         return;
1615 
1616   out:
1617         free_notes_attrs(notes_attrs, i);
1618 }
1619 
1620 static void remove_notes_attrs(struct module *mod)
1621 {
1622         if (mod->notes_attrs)
1623                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1624 }
1625 
1626 #else
1627 
1628 static inline void add_sect_attrs(struct module *mod,
1629                                   const struct load_info *info)
1630 {
1631 }
1632 
1633 static inline void remove_sect_attrs(struct module *mod)
1634 {
1635 }
1636 
1637 static inline void add_notes_attrs(struct module *mod,
1638                                    const struct load_info *info)
1639 {
1640 }
1641 
1642 static inline void remove_notes_attrs(struct module *mod)
1643 {
1644 }
1645 #endif /* CONFIG_KALLSYMS */
1646 
1647 static void add_usage_links(struct module *mod)
1648 {
1649 #ifdef CONFIG_MODULE_UNLOAD
1650         struct module_use *use;
1651         int nowarn;
1652 
1653         mutex_lock(&module_mutex);
1654         list_for_each_entry(use, &mod->target_list, target_list) {
1655                 nowarn = sysfs_create_link(use->target->holders_dir,
1656                                            &mod->mkobj.kobj, mod->name);
1657         }
1658         mutex_unlock(&module_mutex);
1659 #endif
1660 }
1661 
1662 static void del_usage_links(struct module *mod)
1663 {
1664 #ifdef CONFIG_MODULE_UNLOAD
1665         struct module_use *use;
1666 
1667         mutex_lock(&module_mutex);
1668         list_for_each_entry(use, &mod->target_list, target_list)
1669                 sysfs_remove_link(use->target->holders_dir, mod->name);
1670         mutex_unlock(&module_mutex);
1671 #endif
1672 }
1673 
1674 static int module_add_modinfo_attrs(struct module *mod)
1675 {
1676         struct module_attribute *attr;
1677         struct module_attribute *temp_attr;
1678         int error = 0;
1679         int i;
1680 
1681         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1682                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1683                                         GFP_KERNEL);
1684         if (!mod->modinfo_attrs)
1685                 return -ENOMEM;
1686 
1687         temp_attr = mod->modinfo_attrs;
1688         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1689                 if (!attr->test || attr->test(mod)) {
1690                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1691                         sysfs_attr_init(&temp_attr->attr);
1692                         error = sysfs_create_file(&mod->mkobj.kobj,
1693                                         &temp_attr->attr);
1694                         ++temp_attr;
1695                 }
1696         }
1697         return error;
1698 }
1699 
1700 static void module_remove_modinfo_attrs(struct module *mod)
1701 {
1702         struct module_attribute *attr;
1703         int i;
1704 
1705         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1706                 /* pick a field to test for end of list */
1707                 if (!attr->attr.name)
1708                         break;
1709                 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1710                 if (attr->free)
1711                         attr->free(mod);
1712         }
1713         kfree(mod->modinfo_attrs);
1714 }
1715 
1716 static void mod_kobject_put(struct module *mod)
1717 {
1718         DECLARE_COMPLETION_ONSTACK(c);
1719         mod->mkobj.kobj_completion = &c;
1720         kobject_put(&mod->mkobj.kobj);
1721         wait_for_completion(&c);
1722 }
1723 
1724 static int mod_sysfs_init(struct module *mod)
1725 {
1726         int err;
1727         struct kobject *kobj;
1728 
1729         if (!module_sysfs_initialized) {
1730                 pr_err("%s: module sysfs not initialized\n", mod->name);
1731                 err = -EINVAL;
1732                 goto out;
1733         }
1734 
1735         kobj = kset_find_obj(module_kset, mod->name);
1736         if (kobj) {
1737                 pr_err("%s: module is already loaded\n", mod->name);
1738                 kobject_put(kobj);
1739                 err = -EINVAL;
1740                 goto out;
1741         }
1742 
1743         mod->mkobj.mod = mod;
1744 
1745         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1746         mod->mkobj.kobj.kset = module_kset;
1747         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1748                                    "%s", mod->name);
1749         if (err)
1750                 mod_kobject_put(mod);
1751 
1752         /* delay uevent until full sysfs population */
1753 out:
1754         return err;
1755 }
1756 
1757 static int mod_sysfs_setup(struct module *mod,
1758                            const struct load_info *info,
1759                            struct kernel_param *kparam,
1760                            unsigned int num_params)
1761 {
1762         int err;
1763 
1764         err = mod_sysfs_init(mod);
1765         if (err)
1766                 goto out;
1767 
1768         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1769         if (!mod->holders_dir) {
1770                 err = -ENOMEM;
1771                 goto out_unreg;
1772         }
1773 
1774         err = module_param_sysfs_setup(mod, kparam, num_params);
1775         if (err)
1776                 goto out_unreg_holders;
1777 
1778         err = module_add_modinfo_attrs(mod);
1779         if (err)
1780                 goto out_unreg_param;
1781 
1782         add_usage_links(mod);
1783         add_sect_attrs(mod, info);
1784         add_notes_attrs(mod, info);
1785 
1786         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1787         return 0;
1788 
1789 out_unreg_param:
1790         module_param_sysfs_remove(mod);
1791 out_unreg_holders:
1792         kobject_put(mod->holders_dir);
1793 out_unreg:
1794         mod_kobject_put(mod);
1795 out:
1796         return err;
1797 }
1798 
1799 static void mod_sysfs_fini(struct module *mod)
1800 {
1801         remove_notes_attrs(mod);
1802         remove_sect_attrs(mod);
1803         mod_kobject_put(mod);
1804 }
1805 
1806 static void init_param_lock(struct module *mod)
1807 {
1808         mutex_init(&mod->param_lock);
1809 }
1810 #else /* !CONFIG_SYSFS */
1811 
1812 static int mod_sysfs_setup(struct module *mod,
1813                            const struct load_info *info,
1814                            struct kernel_param *kparam,
1815                            unsigned int num_params)
1816 {
1817         return 0;
1818 }
1819 
1820 static void mod_sysfs_fini(struct module *mod)
1821 {
1822 }
1823 
1824 static void module_remove_modinfo_attrs(struct module *mod)
1825 {
1826 }
1827 
1828 static void del_usage_links(struct module *mod)
1829 {
1830 }
1831 
1832 static void init_param_lock(struct module *mod)
1833 {
1834 }
1835 #endif /* CONFIG_SYSFS */
1836 
1837 static void mod_sysfs_teardown(struct module *mod)
1838 {
1839         del_usage_links(mod);
1840         module_remove_modinfo_attrs(mod);
1841         module_param_sysfs_remove(mod);
1842         kobject_put(mod->mkobj.drivers_dir);
1843         kobject_put(mod->holders_dir);
1844         mod_sysfs_fini(mod);
1845 }
1846 
1847 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1848 /*
1849  * LKM RO/NX protection: protect module's text/ro-data
1850  * from modification and any data from execution.
1851  *
1852  * General layout of module is:
1853  *          [text] [read-only-data] [ro-after-init] [writable data]
1854  * text_size -----^                ^               ^               ^
1855  * ro_size ------------------------|               |               |
1856  * ro_after_init_size -----------------------------|               |
1857  * size -----------------------------------------------------------|
1858  *
1859  * These values are always page-aligned (as is base)
1860  */
1861 static void frob_text(const struct module_layout *layout,
1862                       int (*set_memory)(unsigned long start, int num_pages))
1863 {
1864         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1865         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1866         set_memory((unsigned long)layout->base,
1867                    layout->text_size >> PAGE_SHIFT);
1868 }
1869 
1870 static void frob_rodata(const struct module_layout *layout,
1871                         int (*set_memory)(unsigned long start, int num_pages))
1872 {
1873         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1874         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1875         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1876         set_memory((unsigned long)layout->base + layout->text_size,
1877                    (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1878 }
1879 
1880 static void frob_ro_after_init(const struct module_layout *layout,
1881                                 int (*set_memory)(unsigned long start, int num_pages))
1882 {
1883         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1884         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1885         BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1886         set_memory((unsigned long)layout->base + layout->ro_size,
1887                    (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1888 }
1889 
1890 static void frob_writable_data(const struct module_layout *layout,
1891                                int (*set_memory)(unsigned long start, int num_pages))
1892 {
1893         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1894         BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1895         BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1896         set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1897                    (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1898 }
1899 
1900 /* livepatching wants to disable read-only so it can frob module. */
1901 void module_disable_ro(const struct module *mod)
1902 {
1903         if (!rodata_enabled)
1904                 return;
1905 
1906         frob_text(&mod->core_layout, set_memory_rw);
1907         frob_rodata(&mod->core_layout, set_memory_rw);
1908         frob_ro_after_init(&mod->core_layout, set_memory_rw);
1909         frob_text(&mod->init_layout, set_memory_rw);
1910         frob_rodata(&mod->init_layout, set_memory_rw);
1911 }
1912 
1913 void module_enable_ro(const struct module *mod, bool after_init)
1914 {
1915         if (!rodata_enabled)
1916                 return;
1917 
1918         frob_text(&mod->core_layout, set_memory_ro);
1919         frob_rodata(&mod->core_layout, set_memory_ro);
1920         frob_text(&mod->init_layout, set_memory_ro);
1921         frob_rodata(&mod->init_layout, set_memory_ro);
1922 
1923         if (after_init)
1924                 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1925 }
1926 
1927 static void module_enable_nx(const struct module *mod)
1928 {
1929         frob_rodata(&mod->core_layout, set_memory_nx);
1930         frob_ro_after_init(&mod->core_layout, set_memory_nx);
1931         frob_writable_data(&mod->core_layout, set_memory_nx);
1932         frob_rodata(&mod->init_layout, set_memory_nx);
1933         frob_writable_data(&mod->init_layout, set_memory_nx);
1934 }
1935 
1936 static void module_disable_nx(const struct module *mod)
1937 {
1938         frob_rodata(&mod->core_layout, set_memory_x);
1939         frob_ro_after_init(&mod->core_layout, set_memory_x);
1940         frob_writable_data(&mod->core_layout, set_memory_x);
1941         frob_rodata(&mod->init_layout, set_memory_x);
1942         frob_writable_data(&mod->init_layout, set_memory_x);
1943 }
1944 
1945 /* Iterate through all modules and set each module's text as RW */
1946 void set_all_modules_text_rw(void)
1947 {
1948         struct module *mod;
1949 
1950         if (!rodata_enabled)
1951                 return;
1952 
1953         mutex_lock(&module_mutex);
1954         list_for_each_entry_rcu(mod, &modules, list) {
1955                 if (mod->state == MODULE_STATE_UNFORMED)
1956                         continue;
1957 
1958                 frob_text(&mod->core_layout, set_memory_rw);
1959                 frob_text(&mod->init_layout, set_memory_rw);
1960         }
1961         mutex_unlock(&module_mutex);
1962 }
1963 
1964 /* Iterate through all modules and set each module's text as RO */
1965 void set_all_modules_text_ro(void)
1966 {
1967         struct module *mod;
1968 
1969         if (!rodata_enabled)
1970                 return;
1971 
1972         mutex_lock(&module_mutex);
1973         list_for_each_entry_rcu(mod, &modules, list) {
1974                 /*
1975                  * Ignore going modules since it's possible that ro
1976                  * protection has already been disabled, otherwise we'll
1977                  * run into protection faults at module deallocation.
1978                  */
1979                 if (mod->state == MODULE_STATE_UNFORMED ||
1980                         mod->state == MODULE_STATE_GOING)
1981                         continue;
1982 
1983                 frob_text(&mod->core_layout, set_memory_ro);
1984                 frob_text(&mod->init_layout, set_memory_ro);
1985         }
1986         mutex_unlock(&module_mutex);
1987 }
1988 
1989 static void disable_ro_nx(const struct module_layout *layout)
1990 {
1991         if (rodata_enabled) {
1992                 frob_text(layout, set_memory_rw);
1993                 frob_rodata(layout, set_memory_rw);
1994                 frob_ro_after_init(layout, set_memory_rw);
1995         }
1996         frob_rodata(layout, set_memory_x);
1997         frob_ro_after_init(layout, set_memory_x);
1998         frob_writable_data(layout, set_memory_x);
1999 }
2000 
2001 #else
2002 static void disable_ro_nx(const struct module_layout *layout) { }
2003 static void module_enable_nx(const struct module *mod) { }
2004 static void module_disable_nx(const struct module *mod) { }
2005 #endif
2006 
2007 #ifdef CONFIG_LIVEPATCH
2008 /*
2009  * Persist Elf information about a module. Copy the Elf header,
2010  * section header table, section string table, and symtab section
2011  * index from info to mod->klp_info.
2012  */
2013 static int copy_module_elf(struct module *mod, struct load_info *info)
2014 {
2015         unsigned int size, symndx;
2016         int ret;
2017 
2018         size = sizeof(*mod->klp_info);
2019         mod->klp_info = kmalloc(size, GFP_KERNEL);
2020         if (mod->klp_info == NULL)
2021                 return -ENOMEM;
2022 
2023         /* Elf header */
2024         size = sizeof(mod->klp_info->hdr);
2025         memcpy(&mod->klp_info->hdr, info->hdr, size);
2026 
2027         /* Elf section header table */
2028         size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2029         mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
2030         if (mod->klp_info->sechdrs == NULL) {
2031                 ret = -ENOMEM;
2032                 goto free_info;
2033         }
2034         memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2035 
2036         /* Elf section name string table */
2037         size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2038         mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2039         if (mod->klp_info->secstrings == NULL) {
2040                 ret = -ENOMEM;
2041                 goto free_sechdrs;
2042         }
2043         memcpy(mod->klp_info->secstrings, info->secstrings, size);
2044 
2045         /* Elf symbol section index */
2046         symndx = info->index.sym;
2047         mod->klp_info->symndx = symndx;
2048 
2049         /*
2050          * For livepatch modules, core_kallsyms.symtab is a complete
2051          * copy of the original symbol table. Adjust sh_addr to point
2052          * to core_kallsyms.symtab since the copy of the symtab in module
2053          * init memory is freed at the end of do_init_module().
2054          */
2055         mod->klp_info->sechdrs[symndx].sh_addr = \
2056                 (unsigned long) mod->core_kallsyms.symtab;
2057 
2058         return 0;
2059 
2060 free_sechdrs:
2061         kfree(mod->klp_info->sechdrs);
2062 free_info:
2063         kfree(mod->klp_info);
2064         return ret;
2065 }
2066 
2067 static void free_module_elf(struct module *mod)
2068 {
2069         kfree(mod->klp_info->sechdrs);
2070         kfree(mod->klp_info->secstrings);
2071         kfree(mod->klp_info);
2072 }
2073 #else /* !CONFIG_LIVEPATCH */
2074 static int copy_module_elf(struct module *mod, struct load_info *info)
2075 {
2076         return 0;
2077 }
2078 
2079 static void free_module_elf(struct module *mod)
2080 {
2081 }
2082 #endif /* CONFIG_LIVEPATCH */
2083 
2084 void __weak module_memfree(void *module_region)
2085 {
2086         vfree(module_region);
2087 }
2088 
2089 void __weak module_arch_cleanup(struct module *mod)
2090 {
2091 }
2092 
2093 void __weak module_arch_freeing_init(struct module *mod)
2094 {
2095 }
2096 
2097 /* Free a module, remove from lists, etc. */
2098 static void free_module(struct module *mod)
2099 {
2100         trace_module_free(mod);
2101 
2102         mod_sysfs_teardown(mod);
2103 
2104         /* We leave it in list to prevent duplicate loads, but make sure
2105          * that noone uses it while it's being deconstructed. */
2106         mutex_lock(&module_mutex);
2107         mod->state = MODULE_STATE_UNFORMED;
2108         mutex_unlock(&module_mutex);
2109 
2110         /* Remove dynamic debug info */
2111         ddebug_remove_module(mod->name);
2112 
2113         /* Arch-specific cleanup. */
2114         module_arch_cleanup(mod);
2115 
2116         /* Module unload stuff */
2117         module_unload_free(mod);
2118 
2119         /* Free any allocated parameters. */
2120         destroy_params(mod->kp, mod->num_kp);
2121 
2122         if (is_livepatch_module(mod))
2123                 free_module_elf(mod);
2124 
2125         /* Now we can delete it from the lists */
2126         mutex_lock(&module_mutex);
2127         /* Unlink carefully: kallsyms could be walking list. */
2128         list_del_rcu(&mod->list);
2129         mod_tree_remove(mod);
2130         /* Remove this module from bug list, this uses list_del_rcu */
2131         module_bug_cleanup(mod);
2132         /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2133         synchronize_sched();
2134         mutex_unlock(&module_mutex);
2135 
2136         /* This may be empty, but that's OK */
2137         disable_ro_nx(&mod->init_layout);
2138         module_arch_freeing_init(mod);
2139         module_memfree(mod->init_layout.base);
2140         kfree(mod->args);
2141         percpu_modfree(mod);
2142 
2143         /* Free lock-classes; relies on the preceding sync_rcu(). */
2144         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2145 
2146         /* Finally, free the core (containing the module structure) */
2147         disable_ro_nx(&mod->core_layout);
2148         module_memfree(mod->core_layout.base);
2149 
2150 #ifdef CONFIG_MPU
2151         update_protections(current->mm);
2152 #endif
2153 }
2154 
2155 void *__symbol_get(const char *symbol)
2156 {
2157         struct module *owner;
2158         const struct kernel_symbol *sym;
2159 
2160         preempt_disable();
2161         sym = find_symbol(symbol, &owner, NULL, true, true);
2162         if (sym && strong_try_module_get(owner))
2163                 sym = NULL;
2164         preempt_enable();
2165 
2166         return sym ? (void *)sym->value : NULL;
2167 }
2168 EXPORT_SYMBOL_GPL(__symbol_get);
2169 
2170 /*
2171  * Ensure that an exported symbol [global namespace] does not already exist
2172  * in the kernel or in some other module's exported symbol table.
2173  *
2174  * You must hold the module_mutex.
2175  */
2176 static int verify_export_symbols(struct module *mod)
2177 {
2178         unsigned int i;
2179         struct module *owner;
2180         const struct kernel_symbol *s;
2181         struct {
2182                 const struct kernel_symbol *sym;
2183                 unsigned int num;
2184         } arr[] = {
2185                 { mod->syms, mod->num_syms },
2186                 { mod->gpl_syms, mod->num_gpl_syms },
2187                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2188 #ifdef CONFIG_UNUSED_SYMBOLS
2189                 { mod->unused_syms, mod->num_unused_syms },
2190                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2191 #endif
2192         };
2193 
2194         for (i = 0; i < ARRAY_SIZE(arr); i++) {
2195                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2196                         if (find_symbol(s->name, &owner, NULL, true, false)) {
2197                                 pr_err("%s: exports duplicate symbol %s"
2198                                        " (owned by %s)\n",
2199                                        mod->name, s->name, module_name(owner));
2200                                 return -ENOEXEC;
2201                         }
2202                 }
2203         }
2204         return 0;
2205 }
2206 
2207 /* Change all symbols so that st_value encodes the pointer directly. */
2208 static int simplify_symbols(struct module *mod, const struct load_info *info)
2209 {
2210         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2211         Elf_Sym *sym = (void *)symsec->sh_addr;
2212         unsigned long secbase;
2213         unsigned int i;
2214         int ret = 0;
2215         const struct kernel_symbol *ksym;
2216 
2217         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2218                 const char *name = info->strtab + sym[i].st_name;
2219 
2220                 switch (sym[i].st_shndx) {
2221                 case SHN_COMMON:
2222                         /* Ignore common symbols */
2223                         if (!strncmp(name, "__gnu_lto", 9))
2224                                 break;
2225 
2226                         /* We compiled with -fno-common.  These are not
2227                            supposed to happen.  */
2228                         pr_debug("Common symbol: %s\n", name);
2229                         pr_warn("%s: please compile with -fno-common\n",
2230                                mod->name);
2231                         ret = -ENOEXEC;
2232                         break;
2233 
2234                 case SHN_ABS:
2235                         /* Don't need to do anything */
2236                         pr_debug("Absolute symbol: 0x%08lx\n",
2237                                (long)sym[i].st_value);
2238                         break;
2239 
2240                 case SHN_LIVEPATCH:
2241                         /* Livepatch symbols are resolved by livepatch */
2242                         break;
2243 
2244                 case SHN_UNDEF:
2245                         ksym = resolve_symbol_wait(mod, info, name);
2246                         /* Ok if resolved.  */
2247                         if (ksym && !IS_ERR(ksym)) {
2248                                 sym[i].st_value = ksym->value;
2249                                 break;
2250                         }
2251 
2252                         /* Ok if weak.  */
2253                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2254                                 break;
2255 
2256                         pr_warn("%s: Unknown symbol %s (err %li)\n",
2257                                 mod->name, name, PTR_ERR(ksym));
2258                         ret = PTR_ERR(ksym) ?: -ENOENT;
2259                         break;
2260 
2261                 default:
2262                         /* Divert to percpu allocation if a percpu var. */
2263                         if (sym[i].st_shndx == info->index.pcpu)
2264                                 secbase = (unsigned long)mod_percpu(mod);
2265                         else
2266                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2267                         sym[i].st_value += secbase;
2268                         break;
2269                 }
2270         }
2271 
2272         return ret;
2273 }
2274 
2275 static int apply_relocations(struct module *mod, const struct load_info *info)
2276 {
2277         unsigned int i;
2278         int err = 0;
2279 
2280         /* Now do relocations. */
2281         for (i = 1; i < info->hdr->e_shnum; i++) {
2282                 unsigned int infosec = info->sechdrs[i].sh_info;
2283 
2284                 /* Not a valid relocation section? */
2285                 if (infosec >= info->hdr->e_shnum)
2286                         continue;
2287 
2288                 /* Don't bother with non-allocated sections */
2289                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2290                         continue;
2291 
2292                 /* Livepatch relocation sections are applied by livepatch */
2293                 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2294                         continue;
2295 
2296                 if (info->sechdrs[i].sh_type == SHT_REL)
2297                         err = apply_relocate(info->sechdrs, info->strtab,
2298                                              info->index.sym, i, mod);
2299                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2300                         err = apply_relocate_add(info->sechdrs, info->strtab,
2301                                                  info->index.sym, i, mod);
2302                 if (err < 0)
2303                         break;
2304         }
2305         return err;
2306 }
2307 
2308 /* Additional bytes needed by arch in front of individual sections */
2309 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2310                                              unsigned int section)
2311 {
2312         /* default implementation just returns zero */
2313         return 0;
2314 }
2315 
2316 /* Update size with this section: return offset. */
2317 static long get_offset(struct module *mod, unsigned int *size,
2318                        Elf_Shdr *sechdr, unsigned int section)
2319 {
2320         long ret;
2321 
2322         *size += arch_mod_section_prepend(mod, section);
2323         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2324         *size = ret + sechdr->sh_size;
2325         return ret;
2326 }
2327 
2328 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2329    might -- code, read-only data, read-write data, small data.  Tally
2330    sizes, and place the offsets into sh_entsize fields: high bit means it
2331    belongs in init. */
2332 static void layout_sections(struct module *mod, struct load_info *info)
2333 {
2334         static unsigned long const masks[][2] = {
2335                 /* NOTE: all executable code must be the first section
2336                  * in this array; otherwise modify the text_size
2337                  * finder in the two loops below */
2338                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2339                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2340                 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2341                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2342                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2343         };
2344         unsigned int m, i;
2345 
2346         for (i = 0; i < info->hdr->e_shnum; i++)
2347                 info->sechdrs[i].sh_entsize = ~0UL;
2348 
2349         pr_debug("Core section allocation order:\n");
2350         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2351                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2352                         Elf_Shdr *s = &info->sechdrs[i];
2353                         const char *sname = info->secstrings + s->sh_name;
2354 
2355                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2356                             || (s->sh_flags & masks[m][1])
2357                             || s->sh_entsize != ~0UL
2358                             || strstarts(sname, ".init"))
2359                                 continue;
2360                         s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2361                         pr_debug("\t%s\n", sname);
2362                 }
2363                 switch (m) {
2364                 case 0: /* executable */
2365                         mod->core_layout.size = debug_align(mod->core_layout.size);
2366                         mod->core_layout.text_size = mod->core_layout.size;
2367                         break;
2368                 case 1: /* RO: text and ro-data */
2369                         mod->core_layout.size = debug_align(mod->core_layout.size);
2370                         mod->core_layout.ro_size = mod->core_layout.size;
2371                         break;
2372                 case 2: /* RO after init */
2373                         mod->core_layout.size = debug_align(mod->core_layout.size);
2374                         mod->core_layout.ro_after_init_size = mod->core_layout.size;
2375                         break;
2376                 case 4: /* whole core */
2377                         mod->core_layout.size = debug_align(mod->core_layout.size);
2378                         break;
2379                 }
2380         }
2381 
2382         pr_debug("Init section allocation order:\n");
2383         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2384                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2385                         Elf_Shdr *s = &info->sechdrs[i];
2386                         const char *sname = info->secstrings + s->sh_name;
2387 
2388                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2389                             || (s->sh_flags & masks[m][1])
2390                             || s->sh_entsize != ~0UL
2391                             || !strstarts(sname, ".init"))
2392                                 continue;
2393                         s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2394                                          | INIT_OFFSET_MASK);
2395                         pr_debug("\t%s\n", sname);
2396                 }
2397                 switch (m) {
2398                 case 0: /* executable */
2399                         mod->init_layout.size = debug_align(mod->init_layout.size);
2400                         mod->init_layout.text_size = mod->init_layout.size;
2401                         break;
2402                 case 1: /* RO: text and ro-data */
2403                         mod->init_layout.size = debug_align(mod->init_layout.size);
2404                         mod->init_layout.ro_size = mod->init_layout.size;
2405                         break;
2406                 case 2:
2407                         /*
2408                          * RO after init doesn't apply to init_layout (only
2409                          * core_layout), so it just takes the value of ro_size.
2410                          */
2411                         mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2412                         break;
2413                 case 4: /* whole init */
2414                         mod->init_layout.size = debug_align(mod->init_layout.size);
2415                         break;
2416                 }
2417         }
2418 }
2419 
2420 static void set_license(struct module *mod, const char *license)
2421 {
2422         if (!license)
2423                 license = "unspecified";
2424 
2425         if (!license_is_gpl_compatible(license)) {
2426                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2427                         pr_warn("%s: module license '%s' taints kernel.\n",
2428                                 mod->name, license);
2429                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2430                                  LOCKDEP_NOW_UNRELIABLE);
2431         }
2432 }
2433 
2434 /* Parse tag=value strings from .modinfo section */
2435 static char *next_string(char *string, unsigned long *secsize)
2436 {
2437         /* Skip non-zero chars */
2438         while (string[0]) {
2439                 string++;
2440                 if ((*secsize)-- <= 1)
2441                         return NULL;
2442         }
2443 
2444         /* Skip any zero padding. */
2445         while (!string[0]) {
2446                 string++;
2447                 if ((*secsize)-- <= 1)
2448                         return NULL;
2449         }
2450         return string;
2451 }
2452 
2453 static char *get_modinfo(struct load_info *info, const char *tag)
2454 {
2455         char *p;
2456         unsigned int taglen = strlen(tag);
2457         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2458         unsigned long size = infosec->sh_size;
2459 
2460         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2461                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2462                         return p + taglen + 1;
2463         }
2464         return NULL;
2465 }
2466 
2467 static void setup_modinfo(struct module *mod, struct load_info *info)
2468 {
2469         struct module_attribute *attr;
2470         int i;
2471 
2472         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2473                 if (attr->setup)
2474                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2475         }
2476 }
2477 
2478 static void free_modinfo(struct module *mod)
2479 {
2480         struct module_attribute *attr;
2481         int i;
2482 
2483         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2484                 if (attr->free)
2485                         attr->free(mod);
2486         }
2487 }
2488 
2489 #ifdef CONFIG_KALLSYMS
2490 
2491 /* lookup symbol in given range of kernel_symbols */
2492 static const struct kernel_symbol *lookup_symbol(const char *name,
2493         const struct kernel_symbol *start,
2494         const struct kernel_symbol *stop)
2495 {
2496         return bsearch(name, start, stop - start,
2497                         sizeof(struct kernel_symbol), cmp_name);
2498 }
2499 
2500 static int is_exported(const char *name, unsigned long value,
2501                        const struct module *mod)
2502 {
2503         const struct kernel_symbol *ks;
2504         if (!mod)
2505                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2506         else
2507                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2508         return ks != NULL && ks->value == value;
2509 }
2510 
2511 /* As per nm */
2512 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2513 {
2514         const Elf_Shdr *sechdrs = info->sechdrs;
2515 
2516         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2517                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2518                         return 'v';
2519                 else
2520                         return 'w';
2521         }
2522         if (sym->st_shndx == SHN_UNDEF)
2523                 return 'U';
2524         if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2525                 return 'a';
2526         if (sym->st_shndx >= SHN_LORESERVE)
2527                 return '?';
2528         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2529                 return 't';
2530         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2531             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2532                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2533                         return 'r';
2534                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2535                         return 'g';
2536                 else
2537                         return 'd';
2538         }
2539         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2540                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2541                         return 's';
2542                 else
2543                         return 'b';
2544         }
2545         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2546                       ".debug")) {
2547                 return 'n';
2548         }
2549         return '?';
2550 }
2551 
2552 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2553                         unsigned int shnum, unsigned int pcpundx)
2554 {
2555         const Elf_Shdr *sec;
2556 
2557         if (src->st_shndx == SHN_UNDEF
2558             || src->st_shndx >= shnum
2559             || !src->st_name)
2560                 return false;
2561 
2562 #ifdef CONFIG_KALLSYMS_ALL
2563         if (src->st_shndx == pcpundx)
2564                 return true;
2565 #endif
2566 
2567         sec = sechdrs + src->st_shndx;
2568         if (!(sec->sh_flags & SHF_ALLOC)
2569 #ifndef CONFIG_KALLSYMS_ALL
2570             || !(sec->sh_flags & SHF_EXECINSTR)
2571 #endif
2572             || (sec->sh_entsize & INIT_OFFSET_MASK))
2573                 return false;
2574 
2575         return true;
2576 }
2577 
2578 /*
2579  * We only allocate and copy the strings needed by the parts of symtab
2580  * we keep.  This is simple, but has the effect of making multiple
2581  * copies of duplicates.  We could be more sophisticated, see
2582  * linux-kernel thread starting with
2583  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2584  */
2585 static void layout_symtab(struct module *mod, struct load_info *info)
2586 {
2587         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2588         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2589         const Elf_Sym *src;
2590         unsigned int i, nsrc, ndst, strtab_size = 0;
2591 
2592         /* Put symbol section at end of init part of module. */
2593         symsect->sh_flags |= SHF_ALLOC;
2594         symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2595                                          info->index.sym) | INIT_OFFSET_MASK;
2596         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2597 
2598         src = (void *)info->hdr + symsect->sh_offset;
2599         nsrc = symsect->sh_size / sizeof(*src);
2600 
2601         /* Compute total space required for the core symbols' strtab. */
2602         for (ndst = i = 0; i < nsrc; i++) {
2603                 if (i == 0 || is_livepatch_module(mod) ||
2604                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2605                                    info->index.pcpu)) {
2606                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2607                         ndst++;
2608                 }
2609         }
2610 
2611         /* Append room for core symbols at end of core part. */
2612         info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2613         info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2614         mod->core_layout.size += strtab_size;
2615         mod->core_layout.size = debug_align(mod->core_layout.size);
2616 
2617         /* Put string table section at end of init part of module. */
2618         strsect->sh_flags |= SHF_ALLOC;
2619         strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2620                                          info->index.str) | INIT_OFFSET_MASK;
2621         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2622 
2623         /* We'll tack temporary mod_kallsyms on the end. */
2624         mod->init_layout.size = ALIGN(mod->init_layout.size,
2625                                       __alignof__(struct mod_kallsyms));
2626         info->mod_kallsyms_init_off = mod->init_layout.size;
2627         mod->init_layout.size += sizeof(struct mod_kallsyms);
2628         mod->init_layout.size = debug_align(mod->init_layout.size);
2629 }
2630 
2631 /*
2632  * We use the full symtab and strtab which layout_symtab arranged to
2633  * be appended to the init section.  Later we switch to the cut-down
2634  * core-only ones.
2635  */
2636 static void add_kallsyms(struct module *mod, const struct load_info *info)
2637 {
2638         unsigned int i, ndst;
2639         const Elf_Sym *src;
2640         Elf_Sym *dst;
2641         char *s;
2642         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2643 
2644         /* Set up to point into init section. */
2645         mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2646 
2647         mod->kallsyms->symtab = (void *)symsec->sh_addr;
2648         mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2649         /* Make sure we get permanent strtab: don't use info->strtab. */
2650         mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2651 
2652         /* Set types up while we still have access to sections. */
2653         for (i = 0; i < mod->kallsyms->num_symtab; i++)
2654                 mod->kallsyms->symtab[i].st_info
2655                         = elf_type(&mod->kallsyms->symtab[i], info);
2656 
2657         /* Now populate the cut down core kallsyms for after init. */
2658         mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2659         mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2660         src = mod->kallsyms->symtab;
2661         for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2662                 if (i == 0 || is_livepatch_module(mod) ||
2663                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2664                                    info->index.pcpu)) {
2665                         dst[ndst] = src[i];
2666                         dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2667                         s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2668                                      KSYM_NAME_LEN) + 1;
2669                 }
2670         }
2671         mod->core_kallsyms.num_symtab = ndst;
2672 }
2673 #else
2674 static inline void layout_symtab(struct module *mod, struct load_info *info)
2675 {
2676 }
2677 
2678 static void add_kallsyms(struct module *mod, const struct load_info *info)
2679 {
2680 }
2681 #endif /* CONFIG_KALLSYMS */
2682 
2683 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2684 {
2685         if (!debug)
2686                 return;
2687 #ifdef CONFIG_DYNAMIC_DEBUG
2688         if (ddebug_add_module(debug, num, debug->modname))
2689                 pr_err("dynamic debug error adding module: %s\n",
2690                         debug->modname);
2691 #endif
2692 }
2693 
2694 static void dynamic_debug_remove(struct _ddebug *debug)
2695 {
2696         if (debug)
2697                 ddebug_remove_module(debug->modname);
2698 }
2699 
2700 void * __weak module_alloc(unsigned long size)
2701 {
2702         return vmalloc_exec(size);
2703 }
2704 
2705 #ifdef CONFIG_DEBUG_KMEMLEAK
2706 static void kmemleak_load_module(const struct module *mod,
2707                                  const struct load_info *info)
2708 {
2709         unsigned int i;
2710 
2711         /* only scan the sections containing data */
2712         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2713 
2714         for (i = 1; i < info->hdr->e_shnum; i++) {
2715                 /* Scan all writable sections that's not executable */
2716                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2717                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2718                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2719                         continue;
2720 
2721                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2722                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2723         }
2724 }
2725 #else
2726 static inline void kmemleak_load_module(const struct module *mod,
2727                                         const struct load_info *info)
2728 {
2729 }
2730 #endif
2731 
2732 #ifdef CONFIG_MODULE_SIG
2733 static int module_sig_check(struct load_info *info, int flags)
2734 {
2735         int err = -ENOKEY;
2736         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2737         const void *mod = info->hdr;
2738 
2739         /*
2740          * Require flags == 0, as a module with version information
2741          * removed is no longer the module that was signed
2742          */
2743         if (flags == 0 &&
2744             info->len > markerlen &&
2745             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2746                 /* We truncate the module to discard the signature */
2747                 info->len -= markerlen;
2748                 err = mod_verify_sig(mod, &info->len);
2749         }
2750 
2751         if (!err) {
2752                 info->sig_ok = true;
2753                 return 0;
2754         }
2755 
2756         /* Not having a signature is only an error if we're strict. */
2757         if (err == -ENOKEY && !sig_enforce)
2758                 err = 0;
2759 
2760         return err;
2761 }
2762 #else /* !CONFIG_MODULE_SIG */
2763 static int module_sig_check(struct load_info *info, int flags)
2764 {
2765         return 0;
2766 }
2767 #endif /* !CONFIG_MODULE_SIG */
2768 
2769 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2770 static int elf_header_check(struct load_info *info)
2771 {
2772         if (info->len < sizeof(*(info->hdr)))
2773                 return -ENOEXEC;
2774 
2775         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2776             || info->hdr->e_type != ET_REL
2777             || !elf_check_arch(info->hdr)
2778             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2779                 return -ENOEXEC;
2780 
2781         if (info->hdr->e_shoff >= info->len
2782             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2783                 info->len - info->hdr->e_shoff))
2784                 return -ENOEXEC;
2785 
2786         return 0;
2787 }
2788 
2789 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2790 
2791 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2792 {
2793         do {
2794                 unsigned long n = min(len, COPY_CHUNK_SIZE);
2795 
2796                 if (copy_from_user(dst, usrc, n) != 0)
2797                         return -EFAULT;
2798                 cond_resched();
2799                 dst += n;
2800                 usrc += n;
2801                 len -= n;
2802         } while (len);
2803         return 0;
2804 }
2805 
2806 #ifdef CONFIG_LIVEPATCH
2807 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2808 {
2809         if (get_modinfo(info, "livepatch")) {
2810                 mod->klp = true;
2811                 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2812         }
2813 
2814         return 0;
2815 }
2816 #else /* !CONFIG_LIVEPATCH */
2817 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2818 {
2819         if (get_modinfo(info, "livepatch")) {
2820                 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2821                        mod->name);
2822                 return -ENOEXEC;
2823         }
2824 
2825         return 0;
2826 }
2827 #endif /* CONFIG_LIVEPATCH */
2828 
2829 /* Sets info->hdr and info->len. */
2830 static int copy_module_from_user(const void __user *umod, unsigned long len,
2831                                   struct load_info *info)
2832 {
2833         int err;
2834 
2835         info->len = len;
2836         if (info->len < sizeof(*(info->hdr)))
2837                 return -ENOEXEC;
2838 
2839         err = security_kernel_read_file(NULL, READING_MODULE);
2840         if (err)
2841                 return err;
2842 
2843         /* Suck in entire file: we'll want most of it. */
2844         info->hdr = __vmalloc(info->len,
2845                         GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2846         if (!info->hdr)
2847                 return -ENOMEM;
2848 
2849         if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2850                 vfree(info->hdr);
2851                 return -EFAULT;
2852         }
2853 
2854         return 0;
2855 }
2856 
2857 static void free_copy(struct load_info *info)
2858 {
2859         vfree(info->hdr);
2860 }
2861 
2862 static int rewrite_section_headers(struct load_info *info, int flags)
2863 {
2864         unsigned int i;
2865 
2866         /* This should always be true, but let's be sure. */
2867         info->sechdrs[0].sh_addr = 0;
2868 
2869         for (i = 1; i < info->hdr->e_shnum; i++) {
2870                 Elf_Shdr *shdr = &info->sechdrs[i];
2871                 if (shdr->sh_type != SHT_NOBITS
2872                     && info->len < shdr->sh_offset + shdr->sh_size) {
2873                         pr_err("Module len %lu truncated\n", info->len);
2874                         return -ENOEXEC;
2875                 }
2876 
2877                 /* Mark all sections sh_addr with their address in the
2878                    temporary image. */
2879                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2880 
2881 #ifndef CONFIG_MODULE_UNLOAD
2882                 /* Don't load .exit sections */
2883                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2884                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2885 #endif
2886         }
2887 
2888         /* Track but don't keep modinfo and version sections. */
2889         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2890                 info->index.vers = 0; /* Pretend no __versions section! */
2891         else
2892                 info->index.vers = find_sec(info, "__versions");
2893         info->index.info = find_sec(info, ".modinfo");
2894         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2895         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2896         return 0;
2897 }
2898 
2899 /*
2900  * Set up our basic convenience variables (pointers to section headers,
2901  * search for module section index etc), and do some basic section
2902  * verification.
2903  *
2904  * Return the temporary module pointer (we'll replace it with the final
2905  * one when we move the module sections around).
2906  */
2907 static struct module *setup_load_info(struct load_info *info, int flags)
2908 {
2909         unsigned int i;
2910         int err;
2911         struct module *mod;
2912 
2913         /* Set up the convenience variables */
2914         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2915         info->secstrings = (void *)info->hdr
2916                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2917 
2918         err = rewrite_section_headers(info, flags);
2919         if (err)
2920                 return ERR_PTR(err);
2921 
2922         /* Find internal symbols and strings. */
2923         for (i = 1; i < info->hdr->e_shnum; i++) {
2924                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2925                         info->index.sym = i;
2926                         info->index.str = info->sechdrs[i].sh_link;
2927                         info->strtab = (char *)info->hdr
2928                                 + info->sechdrs[info->index.str].sh_offset;
2929                         break;
2930                 }
2931         }
2932 
2933         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2934         if (!info->index.mod) {
2935                 pr_warn("No module found in object\n");
2936                 return ERR_PTR(-ENOEXEC);
2937         }
2938         /* This is temporary: point mod into copy of data. */
2939         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2940 
2941         if (info->index.sym == 0) {
2942                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2943                 return ERR_PTR(-ENOEXEC);
2944         }
2945 
2946         info->index.pcpu = find_pcpusec(info);
2947 
2948         /* Check module struct version now, before we try to use module. */
2949         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2950                 return ERR_PTR(-ENOEXEC);
2951 
2952         return mod;
2953 }
2954 
2955 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2956 {
2957         const char *modmagic = get_modinfo(info, "vermagic");
2958         int err;
2959 
2960         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2961                 modmagic = NULL;
2962 
2963         /* This is allowed: modprobe --force will invalidate it. */
2964         if (!modmagic) {
2965                 err = try_to_force_load(mod, "bad vermagic");
2966                 if (err)
2967                         return err;
2968         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2969                 pr_err("%s: version magic '%s' should be '%s'\n",
2970                        mod->name, modmagic, vermagic);
2971                 return -ENOEXEC;
2972         }
2973 
2974         if (!get_modinfo(info, "intree")) {
2975                 if (!test_taint(TAINT_OOT_MODULE))
2976                         pr_warn("%s: loading out-of-tree module taints kernel.\n",
2977                                 mod->name);
2978                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2979         }
2980 
2981         if (get_modinfo(info, "staging")) {
2982                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2983                 pr_warn("%s: module is from the staging directory, the quality "
2984                         "is unknown, you have been warned.\n", mod->name);
2985         }
2986 
2987         err = check_modinfo_livepatch(mod, info);
2988         if (err)
2989                 return err;
2990 
2991         /* Set up license info based on the info section */
2992         set_license(mod, get_modinfo(info, "license"));
2993 
2994         return 0;
2995 }
2996 
2997 static int find_module_sections(struct module *mod, struct load_info *info)
2998 {
2999         mod->kp = section_objs(info, "__param",
3000                                sizeof(*mod->kp), &mod->num_kp);
3001         mod->syms = section_objs(info, "__ksymtab",
3002                                  sizeof(*mod->syms), &mod->num_syms);
3003         mod->crcs = section_addr(info, "__kcrctab");
3004         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3005                                      sizeof(*mod->gpl_syms),
3006                                      &mod->num_gpl_syms);
3007         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3008         mod->gpl_future_syms = section_objs(info,
3009                                             "__ksymtab_gpl_future",
3010                                             sizeof(*mod->gpl_future_syms),
3011                                             &mod->num_gpl_future_syms);
3012         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3013 
3014 #ifdef CONFIG_UNUSED_SYMBOLS
3015         mod->unused_syms = section_objs(info, "__ksymtab_unused",
3016                                         sizeof(*mod->unused_syms),
3017                                         &mod->num_unused_syms);
3018         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3019         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3020                                             sizeof(*mod->unused_gpl_syms),
3021                                             &mod->num_unused_gpl_syms);
3022         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3023 #endif
3024 #ifdef CONFIG_CONSTRUCTORS
3025         mod->ctors = section_objs(info, ".ctors",
3026                                   sizeof(*mod->ctors), &mod->num_ctors);
3027         if (!mod->ctors)
3028                 mod->ctors = section_objs(info, ".init_array",
3029                                 sizeof(*mod->ctors), &mod->num_ctors);
3030         else if (find_sec(info, ".init_array")) {
3031                 /*
3032                  * This shouldn't happen with same compiler and binutils
3033                  * building all parts of the module.
3034                  */
3035                 pr_warn("%s: has both .ctors and .init_array.\n",
3036                        mod->name);
3037                 return -EINVAL;
3038         }
3039 #endif
3040 
3041 #ifdef CONFIG_TRACEPOINTS
3042         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3043                                              sizeof(*mod->tracepoints_ptrs),
3044                                              &mod->num_tracepoints);
3045 #endif
3046 #ifdef HAVE_JUMP_LABEL
3047         mod->jump_entries = section_objs(info, "__jump_table",
3048                                         sizeof(*mod->jump_entries),
3049                                         &mod->num_jump_entries);
3050 #endif
3051 #ifdef CONFIG_EVENT_TRACING
3052         mod->trace_events = section_objs(info, "_ftrace_events",
3053                                          sizeof(*mod->trace_events),
3054                                          &mod->num_trace_events);
3055         mod->trace_enums = section_objs(info, "_ftrace_enum_map",
3056                                         sizeof(*mod->trace_enums),
3057                                         &mod->num_trace_enums);
3058 #endif
3059 #ifdef CONFIG_TRACING
3060         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3061                                          sizeof(*mod->trace_bprintk_fmt_start),
3062                                          &mod->num_trace_bprintk_fmt);
3063 #endif
3064 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3065         /* sechdrs[0].sh_size is always zero */
3066         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3067                                              sizeof(*mod->ftrace_callsites),
3068                                              &mod->num_ftrace_callsites);
3069 #endif
3070 
3071         mod->extable = section_objs(info, "__ex_table",
3072                                     sizeof(*mod->extable), &mod->num_exentries);
3073 
3074         if (section_addr(info, "__obsparm"))
3075                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3076 
3077         info->debug = section_objs(info, "__verbose",
3078                                    sizeof(*info->debug), &info->num_debug);
3079 
3080         return 0;
3081 }
3082 
3083 static int move_module(struct module *mod, struct load_info *info)
3084 {
3085         int i;
3086         void *ptr;
3087 
3088         /* Do the allocs. */
3089         ptr = module_alloc(mod->core_layout.size);
3090         /*
3091          * The pointer to this block is stored in the module structure
3092          * which is inside the block. Just mark it as not being a
3093          * leak.
3094          */
3095         kmemleak_not_leak(ptr);
3096         if (!ptr)
3097                 return -ENOMEM;
3098 
3099         memset(ptr, 0, mod->core_layout.size);
3100         mod->core_layout.base = ptr;
3101 
3102         if (mod->init_layout.size) {
3103                 ptr = module_alloc(mod->init_layout.size);
3104                 /*
3105                  * The pointer to this block is stored in the module structure
3106                  * which is inside the block. This block doesn't need to be
3107                  * scanned as it contains data and code that will be freed
3108                  * after the module is initialized.
3109                  */
3110                 kmemleak_ignore(ptr);
3111                 if (!ptr) {
3112                         module_memfree(mod->core_layout.base);
3113                         return -ENOMEM;
3114                 }
3115                 memset(ptr, 0, mod->init_layout.size);
3116                 mod->init_layout.base = ptr;
3117         } else
3118                 mod->init_layout.base = NULL;
3119 
3120         /* Transfer each section which specifies SHF_ALLOC */
3121         pr_debug("final section addresses:\n");
3122         for (i = 0; i < info->hdr->e_shnum; i++) {
3123                 void *dest;
3124                 Elf_Shdr *shdr = &info->sechdrs[i];
3125 
3126                 if (!(shdr->sh_flags & SHF_ALLOC))
3127                         continue;
3128 
3129                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3130                         dest = mod->init_layout.base
3131                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3132                 else
3133                         dest = mod->core_layout.base + shdr->sh_entsize;
3134 
3135                 if (shdr->sh_type != SHT_NOBITS)
3136                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3137                 /* Update sh_addr to point to copy in image. */
3138                 shdr->sh_addr = (unsigned long)dest;
3139                 pr_debug("\t0x%lx %s\n",
3140                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3141         }
3142 
3143         return 0;
3144 }
3145 
3146 static int check_module_license_and_versions(struct module *mod)
3147 {
3148         int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3149 
3150         /*
3151          * ndiswrapper is under GPL by itself, but loads proprietary modules.
3152          * Don't use add_taint_module(), as it would prevent ndiswrapper from
3153          * using GPL-only symbols it needs.
3154          */
3155         if (strcmp(mod->name, "ndiswrapper") == 0)
3156                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3157 
3158         /* driverloader was caught wrongly pretending to be under GPL */
3159         if (strcmp(mod->name, "driverloader") == 0)
3160                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3161                                  LOCKDEP_NOW_UNRELIABLE);
3162 
3163         /* lve claims to be GPL but upstream won't provide source */
3164         if (strcmp(mod->name, "lve") == 0)
3165                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3166                                  LOCKDEP_NOW_UNRELIABLE);
3167 
3168         if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3169                 pr_warn("%s: module license taints kernel.\n", mod->name);
3170 
3171 #ifdef CONFIG_MODVERSIONS
3172         if ((mod->num_syms && !mod->crcs)
3173             || (mod->num_gpl_syms && !mod->gpl_crcs)
3174             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3175 #ifdef CONFIG_UNUSED_SYMBOLS
3176             || (mod->num_unused_syms && !mod->unused_crcs)
3177             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3178 #endif
3179                 ) {
3180                 return try_to_force_load(mod,
3181                                          "no versions for exported symbols");
3182         }
3183 #endif
3184         return 0;
3185 }
3186 
3187 static void flush_module_icache(const struct module *mod)
3188 {
3189         mm_segment_t old_fs;
3190 
3191         /* flush the icache in correct context */
3192         old_fs = get_fs();
3193         set_fs(KERNEL_DS);
3194 
3195         /*
3196          * Flush the instruction cache, since we've played with text.
3197          * Do it before processing of module parameters, so the module
3198          * can provide parameter accessor functions of its own.
3199          */
3200         if (mod->init_layout.base)
3201                 flush_icache_range((unsigned long)mod->init_layout.base,
3202                                    (unsigned long)mod->init_layout.base
3203                                    + mod->init_layout.size);
3204         flush_icache_range((unsigned long)mod->core_layout.base,
3205                            (unsigned long)mod->core_layout.base + mod->core_layout.size);
3206 
3207         set_fs(old_fs);
3208 }
3209 
3210 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3211                                      Elf_Shdr *sechdrs,
3212                                      char *secstrings,
3213                                      struct module *mod)
3214 {
3215         return 0;
3216 }
3217 
3218 /* module_blacklist is a comma-separated list of module names */
3219 static char *module_blacklist;
3220 static bool blacklisted(char *module_name)
3221 {
3222         const char *p;
3223         size_t len;
3224 
3225         if (!module_blacklist)
3226                 return false;
3227 
3228         for (p = module_blacklist; *p; p += len) {
3229                 len = strcspn(p, ",");
3230                 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3231                         return true;
3232                 if (p[len] == ',')
3233                         len++;
3234         }
3235         return false;
3236 }
3237 core_param(module_blacklist, module_blacklist, charp, 0400);
3238 
3239 static struct module *layout_and_allocate(struct load_info *info, int flags)
3240 {
3241         /* Module within temporary copy. */
3242         struct module *mod;
3243         unsigned int ndx;
3244         int err;
3245 
3246         mod = setup_load_info(info, flags);
3247         if (IS_ERR(mod))
3248                 return mod;
3249 
3250         if (blacklisted(mod->name))
3251                 return ERR_PTR(-EPERM);
3252 
3253         err = check_modinfo(mod, info, flags);
3254         if (err)
3255                 return ERR_PTR(err);
3256 
3257         /* Allow arches to frob section contents and sizes.  */
3258         err = module_frob_arch_sections(info->hdr, info->sechdrs,
3259                                         info->secstrings, mod);
3260         if (err < 0)
3261                 return ERR_PTR(err);
3262 
3263         /* We will do a special allocation for per-cpu sections later. */
3264         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3265 
3266         /*
3267          * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3268          * layout_sections() can put it in the right place.
3269          * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3270          */
3271         ndx = find_sec(info, ".data..ro_after_init");
3272         if (ndx)
3273                 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3274 
3275         /* Determine total sizes, and put offsets in sh_entsize.  For now
3276            this is done generically; there doesn't appear to be any
3277            special cases for the architectures. */
3278         layout_sections(mod, info);
3279         layout_symtab(mod, info);
3280 
3281         /* Allocate and move to the final place */
3282         err = move_module(mod, info);
3283         if (err)
3284                 return ERR_PTR(err);
3285 
3286         /* Module has been copied to its final place now: return it. */
3287         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3288         kmemleak_load_module(mod, info);
3289         return mod;
3290 }
3291 
3292 /* mod is no longer valid after this! */
3293 static void module_deallocate(struct module *mod, struct load_info *info)
3294 {
3295         percpu_modfree(mod);
3296         module_arch_freeing_init(mod);
3297         module_memfree(mod->init_layout.base);
3298         module_memfree(mod->core_layout.base);
3299 }
3300 
3301 int __weak module_finalize(const Elf_Ehdr *hdr,
3302                            const Elf_Shdr *sechdrs,
3303                            struct module *me)
3304 {
3305         return 0;
3306 }
3307 
3308 static int post_relocation(struct module *mod, const struct load_info *info)
3309 {
3310         /* Sort exception table now relocations are done. */
3311         sort_extable(mod->extable, mod->extable + mod->num_exentries);
3312 
3313         /* Copy relocated percpu area over. */
3314         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3315                        info->sechdrs[info->index.pcpu].sh_size);
3316 
3317         /* Setup kallsyms-specific fields. */
3318         add_kallsyms(mod, info);
3319 
3320         /* Arch-specific module finalizing. */
3321         return module_finalize(info->hdr, info->sechdrs, mod);
3322 }
3323 
3324 /* Is this module of this name done loading?  No locks held. */
3325 static bool finished_loading(const char *name)
3326 {
3327         struct module *mod;
3328         bool ret;
3329 
3330         /*
3331          * The module_mutex should not be a heavily contended lock;
3332          * if we get the occasional sleep here, we'll go an extra iteration
3333          * in the wait_event_interruptible(), which is harmless.
3334          */
3335         sched_annotate_sleep();
3336         mutex_lock(&module_mutex);
3337         mod = find_module_all(name, strlen(name), true);
3338         ret = !mod || mod->state == MODULE_STATE_LIVE
3339                 || mod->state == MODULE_STATE_GOING;
3340         mutex_unlock(&module_mutex);
3341 
3342         return ret;
3343 }
3344 
3345 /* Call module constructors. */
3346 static void do_mod_ctors(struct module *mod)
3347 {
3348 #ifdef CONFIG_CONSTRUCTORS
3349         unsigned long i;
3350 
3351         for (i = 0; i < mod->num_ctors; i++)
3352                 mod->ctors[i]();
3353 #endif
3354 }
3355 
3356 /* For freeing module_init on success, in case kallsyms traversing */
3357 struct mod_initfree {
3358         struct rcu_head rcu;
3359         void *module_init;
3360 };
3361 
3362 static void do_free_init(struct rcu_head *head)
3363 {
3364         struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3365         module_memfree(m->module_init);
3366         kfree(m);
3367 }
3368 
3369 /*
3370  * This is where the real work happens.
3371  *
3372  * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3373  * helper command 'lx-symbols'.
3374  */
3375 static noinline int do_init_module(struct module *mod)
3376 {
3377         int ret = 0;
3378         struct mod_initfree *freeinit;
3379 
3380         freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3381         if (!freeinit) {
3382                 ret = -ENOMEM;
3383                 goto fail;
3384         }
3385         freeinit->module_init = mod->init_layout.base;
3386 
3387         /*
3388          * We want to find out whether @mod uses async during init.  Clear
3389          * PF_USED_ASYNC.  async_schedule*() will set it.
3390          */
3391         current->flags &= ~PF_USED_ASYNC;
3392 
3393         do_mod_ctors(mod);
3394         /* Start the module */
3395         if (mod->init != NULL)
3396                 ret = do_one_initcall(mod->init);
3397         if (ret < 0) {
3398                 goto fail_free_freeinit;
3399         }
3400         if (ret > 0) {
3401                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3402                         "follow 0/-E convention\n"
3403                         "%s: loading module anyway...\n",
3404                         __func__, mod->name, ret, __func__);
3405                 dump_stack();
3406         }
3407 
3408         /* Now it's a first class citizen! */
3409         mod->state = MODULE_STATE_LIVE;
3410         blocking_notifier_call_chain(&module_notify_list,
3411                                      MODULE_STATE_LIVE, mod);
3412 
3413         /*
3414          * We need to finish all async code before the module init sequence
3415          * is done.  This has potential to deadlock.  For example, a newly
3416          * detected block device can trigger request_module() of the
3417          * default iosched from async probing task.  Once userland helper
3418          * reaches here, async_synchronize_full() will wait on the async
3419          * task waiting on request_module() and deadlock.
3420          *
3421          * This deadlock is avoided by perfomring async_synchronize_full()
3422          * iff module init queued any async jobs.  This isn't a full
3423          * solution as it will deadlock the same if module loading from
3424          * async jobs nests more than once; however, due to the various
3425          * constraints, this hack seems to be the best option for now.
3426          * Please refer to the following thread for details.
3427          *
3428          * http://thread.gmane.org/gmane.linux.kernel/1420814
3429          */
3430         if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3431                 async_synchronize_full();
3432 
3433         mutex_lock(&module_mutex);
3434         /* Drop initial reference. */
3435         module_put(mod);
3436         trim_init_extable(mod);
3437 #ifdef CONFIG_KALLSYMS
3438         /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3439         rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3440 #endif
3441         module_enable_ro(mod, true);
3442         mod_tree_remove_init(mod);
3443         disable_ro_nx(&mod->init_layout);
3444         module_arch_freeing_init(mod);
3445         mod->init_layout.base = NULL;
3446         mod->init_layout.size = 0;
3447         mod->init_layout.ro_size = 0;
3448         mod->init_layout.ro_after_init_size = 0;
3449         mod->init_layout.text_size = 0;
3450         /*
3451          * We want to free module_init, but be aware that kallsyms may be
3452          * walking this with preempt disabled.  In all the failure paths, we
3453          * call synchronize_sched(), but we don't want to slow down the success
3454          * path, so use actual RCU here.
3455          */
3456         call_rcu_sched(&freeinit->rcu, do_free_init);
3457         mutex_unlock(&module_mutex);
3458         wake_up_all(&module_wq);
3459 
3460         return 0;
3461 
3462 fail_free_freeinit:
3463         kfree(freeinit);
3464 fail:
3465         /* Try to protect us from buggy refcounters. */
3466         mod->state = MODULE_STATE_GOING;
3467         synchronize_sched();
3468         module_put(mod);
3469         blocking_notifier_call_chain(&module_notify_list,
3470                                      MODULE_STATE_GOING, mod);
3471         klp_module_going(mod);
3472         ftrace_release_mod(mod);
3473         free_module(mod);
3474         wake_up_all(&module_wq);
3475         return ret;
3476 }
3477 
3478 static int may_init_module(void)
3479 {
3480         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3481                 return -EPERM;
3482 
3483         return 0;
3484 }
3485 
3486 /*
3487  * We try to place it in the list now to make sure it's unique before
3488  * we dedicate too many resources.  In particular, temporary percpu
3489  * memory exhaustion.
3490  */
3491 static int add_unformed_module(struct module *mod)
3492 {
3493         int err;
3494         struct module *old;
3495 
3496         mod->state = MODULE_STATE_UNFORMED;
3497 
3498 again:
3499         mutex_lock(&module_mutex);
3500         old = find_module_all(mod->name, strlen(mod->name), true);
3501         if (old != NULL) {
3502                 if (old->state == MODULE_STATE_COMING
3503                     || old->state == MODULE_STATE_UNFORMED) {
3504                         /* Wait in case it fails to load. */
3505                         mutex_unlock(&module_mutex);
3506                         err = wait_event_interruptible(module_wq,
3507                                                finished_loading(mod->name));
3508                         if (err)
3509                                 goto out_unlocked;
3510                         goto again;
3511                 }
3512                 err = -EEXIST;
3513                 goto out;
3514         }
3515         mod_update_bounds(mod);
3516         list_add_rcu(&mod->list, &modules);
3517         mod_tree_insert(mod);
3518         err = 0;
3519 
3520 out:
3521         mutex_unlock(&module_mutex);
3522 out_unlocked:
3523         return err;
3524 }
3525 
3526 static int complete_formation(struct module *mod, struct load_info *info)
3527 {
3528         int err;
3529 
3530         mutex_lock(&module_mutex);
3531 
3532         /* Find duplicate symbols (must be called under lock). */
3533         err = verify_export_symbols(mod);
3534         if (err < 0)
3535                 goto out;
3536 
3537         /* This relies on module_mutex for list integrity. */
3538         module_bug_finalize(info->hdr, info->sechdrs, mod);
3539 
3540         module_enable_ro(mod, false);
3541         module_enable_nx(mod);
3542 
3543         /* Mark state as coming so strong_try_module_get() ignores us,
3544          * but kallsyms etc. can see us. */
3545         mod->state = MODULE_STATE_COMING;
3546         mutex_unlock(&module_mutex);
3547 
3548         return 0;
3549 
3550 out:
3551         mutex_unlock(&module_mutex);
3552         return err;
3553 }
3554 
3555 static int prepare_coming_module(struct module *mod)
3556 {
3557         int err;
3558 
3559         ftrace_module_enable(mod);
3560         err = klp_module_coming(mod);
3561         if (err)
3562                 return err;
3563 
3564         blocking_notifier_call_chain(&module_notify_list,
3565                                      MODULE_STATE_COMING, mod);
3566         return 0;
3567 }
3568 
3569 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3570                                    void *arg)
3571 {
3572         struct module *mod = arg;
3573         int ret;
3574 
3575         if (strcmp(param, "async_probe") == 0) {
3576                 mod->async_probe_requested = true;
3577                 return 0;
3578         }
3579 
3580         /* Check for magic 'dyndbg' arg */
3581         ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3582         if (ret != 0)
3583                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3584         return 0;
3585 }
3586 
3587 /* Allocate and load the module: note that size of section 0 is always
3588    zero, and we rely on this for optional sections. */
3589 static int load_module(struct load_info *info, const char __user *uargs,
3590                        int flags)
3591 {
3592         struct module *mod;
3593         long err;
3594         char *after_dashes;
3595 
3596         err = module_sig_check(info, flags);
3597         if (err)
3598                 goto free_copy;
3599 
3600         err = elf_header_check(info);
3601         if (err)
3602                 goto free_copy;
3603 
3604         /* Figure out module layout, and allocate all the memory. */
3605         mod = layout_and_allocate(info, flags);
3606         if (IS_ERR(mod)) {
3607                 err = PTR_ERR(mod);
3608                 goto free_copy;
3609         }
3610 
3611         /* Reserve our place in the list. */
3612         err = add_unformed_module(mod);
3613         if (err)
3614                 goto free_module;
3615 
3616 #ifdef CONFIG_MODULE_SIG
3617         mod->sig_ok = info->sig_ok;
3618         if (!mod->sig_ok) {
3619                 pr_notice_once("%s: module verification failed: signature "
3620                                "and/or required key missing - tainting "
3621                                "kernel\n", mod->name);
3622                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3623         }
3624 #endif
3625 
3626         /* To avoid stressing percpu allocator, do this once we're unique. */
3627         err = percpu_modalloc(mod, info);
3628         if (err)
3629                 goto unlink_mod;
3630 
3631         /* Now module is in final location, initialize linked lists, etc. */
3632         err = module_unload_init(mod);
3633         if (err)
3634                 goto unlink_mod;
3635 
3636         init_param_lock(mod);
3637 
3638         /* Now we've got everything in the final locations, we can
3639          * find optional sections. */
3640         err = find_module_sections(mod, info);
3641         if (err)
3642                 goto free_unload;
3643 
3644         err = check_module_license_and_versions(mod);
3645         if (err)
3646                 goto free_unload;
3647 
3648         /* Set up MODINFO_ATTR fields */
3649         setup_modinfo(mod, info);
3650 
3651         /* Fix up syms, so that st_value is a pointer to location. */
3652         err = simplify_symbols(mod, info);
3653         if (err < 0)
3654                 goto free_modinfo;
3655 
3656         err = apply_relocations(mod, info);
3657         if (err < 0)
3658                 goto free_modinfo;
3659 
3660         err = post_relocation(mod, info);
3661         if (err < 0)
3662                 goto free_modinfo;
3663 
3664         flush_module_icache(mod);
3665 
3666         /* Now copy in args */
3667         mod->args = strndup_user(uargs, ~0UL >> 1);
3668         if (IS_ERR(mod->args)) {
3669                 err = PTR_ERR(mod->args);
3670                 goto free_arch_cleanup;
3671         }
3672 
3673         dynamic_debug_setup(info->debug, info->num_debug);
3674 
3675         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3676         ftrace_module_init(mod);
3677 
3678         /* Finally it's fully formed, ready to start executing. */
3679         err = complete_formation(mod, info);
3680         if (err)
3681                 goto ddebug_cleanup;
3682 
3683         err = prepare_coming_module(mod);
3684         if (err)
3685                 goto bug_cleanup;
3686 
3687         /* Module is ready to execute: parsing args may do that. */
3688         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3689                                   -32768, 32767, mod,
3690                                   unknown_module_param_cb);
3691         if (IS_ERR(after_dashes)) {
3692                 err = PTR_ERR(after_dashes);
3693                 goto coming_cleanup;
3694         } else if (after_dashes) {
3695                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3696                        mod->name, after_dashes);
3697         }
3698 
3699         /* Link in to syfs. */
3700         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3701         if (err < 0)
3702                 goto coming_cleanup;
3703 
3704         if (is_livepatch_module(mod)) {
3705                 err = copy_module_elf(mod, info);
3706                 if (err < 0)
3707                         goto sysfs_cleanup;
3708         }
3709 
3710         /* Get rid of temporary copy. */
3711         free_copy(info);
3712 
3713         /* Done! */
3714         trace_module_load(mod);
3715 
3716         return do_init_module(mod);
3717 
3718  sysfs_cleanup:
3719         mod_sysfs_teardown(mod);
3720  coming_cleanup:
3721         mod->state = MODULE_STATE_GOING;
3722         blocking_notifier_call_chain(&module_notify_list,
3723                                      MODULE_STATE_GOING, mod);
3724         klp_module_going(mod);
3725  bug_cleanup:
3726         /* module_bug_cleanup needs module_mutex protection */
3727         mutex_lock(&module_mutex);
3728         module_bug_cleanup(mod);
3729         mutex_unlock(&module_mutex);
3730 
3731         /* we can't deallocate the module until we clear memory protection */
3732         module_disable_ro(mod);
3733         module_disable_nx(mod);
3734 
3735  ddebug_cleanup:
3736         dynamic_debug_remove(info->debug);
3737         synchronize_sched();
3738         kfree(mod->args);
3739  free_arch_cleanup:
3740         module_arch_cleanup(mod);
3741  free_modinfo:
3742         free_modinfo(mod);
3743  free_unload:
3744         module_unload_free(mod);
3745  unlink_mod:
3746         mutex_lock(&module_mutex);
3747         /* Unlink carefully: kallsyms could be walking list. */
3748         list_del_rcu(&mod->list);
3749         mod_tree_remove(mod);
3750         wake_up_all(&module_wq);
3751         /* Wait for RCU-sched synchronizing before releasing mod->list. */
3752         synchronize_sched();
3753         mutex_unlock(&module_mutex);
3754  free_module:
3755         /*
3756          * Ftrace needs to clean up what it initialized.
3757          * This does nothing if ftrace_module_init() wasn't called,
3758          * but it must be called outside of module_mutex.
3759          */
3760         ftrace_release_mod(mod);
3761         /* Free lock-classes; relies on the preceding sync_rcu() */
3762         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3763 
3764         module_deallocate(mod, info);
3765  free_copy:
3766         free_copy(info);
3767         return err;
3768 }
3769 
3770 SYSCALL_DEFINE3(init_module, void __user *, umod,
3771                 unsigned long, len, const char __user *, uargs)
3772 {
3773         int err;
3774         struct load_info info = { };
3775 
3776         err = may_init_module();
3777         if (err)
3778                 return err;
3779 
3780         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3781                umod, len, uargs);
3782 
3783         err = copy_module_from_user(umod, len, &info);
3784         if (err)
3785                 return err;
3786 
3787         return load_module(&info, uargs, 0);
3788 }
3789 
3790 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3791 {
3792         struct load_info info = { };
3793         loff_t size;
3794         void *hdr;
3795         int err;
3796 
3797         err = may_init_module();
3798         if (err)
3799                 return err;
3800 
3801         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3802 
3803         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3804                       |MODULE_INIT_IGNORE_VERMAGIC))
3805                 return -EINVAL;
3806 
3807         err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3808                                        READING_MODULE);
3809         if (err)
3810                 return err;
3811         info.hdr = hdr;
3812         info.len = size;
3813 
3814         return load_module(&info, uargs, flags);
3815 }
3816 
3817 static inline int within(unsigned long addr, void *start, unsigned long size)
3818 {
3819         return ((void *)addr >= start && (void *)addr < start + size);
3820 }
3821 
3822 #ifdef CONFIG_KALLSYMS
3823 /*
3824  * This ignores the intensely annoying "mapping symbols" found
3825  * in ARM ELF files: $a, $t and $d.
3826  */
3827 static inline int is_arm_mapping_symbol(const char *str)
3828 {
3829         if (str[0] == '.' && str[1] == 'L')
3830                 return true;
3831         return str[0] == '$' && strchr("axtd", str[1])
3832                && (str[2] == '\0' || str[2] == '.');
3833 }
3834 
3835 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3836 {
3837         return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3838 }
3839 
3840 static const char *get_ksymbol(struct module *mod,
3841                                unsigned long addr,
3842                                unsigned long *size,
3843                                unsigned long *offset)
3844 {
3845         unsigned int i, best = 0;
3846         unsigned long nextval;
3847         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3848 
3849         /* At worse, next value is at end of module */
3850         if (within_module_init(addr, mod))
3851                 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3852         else
3853                 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3854 
3855         /* Scan for closest preceding symbol, and next symbol. (ELF
3856            starts real symbols at 1). */
3857         for (i = 1; i < kallsyms->num_symtab; i++) {
3858                 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3859                         continue;
3860 
3861                 /* We ignore unnamed symbols: they're uninformative
3862                  * and inserted at a whim. */
3863                 if (*symname(kallsyms, i) == '\0'
3864                     || is_arm_mapping_symbol(symname(kallsyms, i)))
3865                         continue;
3866 
3867                 if (kallsyms->symtab[i].st_value <= addr
3868                     && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3869                         best = i;
3870                 if (kallsyms->symtab[i].st_value > addr
3871                     && kallsyms->symtab[i].st_value < nextval)
3872                         nextval = kallsyms->symtab[i].st_value;
3873         }
3874 
3875         if (!best)
3876                 return NULL;
3877 
3878         if (size)
3879                 *size = nextval - kallsyms->symtab[best].st_value;
3880         if (offset)
3881                 *offset = addr - kallsyms->symtab[best].st_value;
3882         return symname(kallsyms, best);
3883 }
3884 
3885 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3886  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3887 const char *module_address_lookup(unsigned long addr,
3888                             unsigned long *size,
3889                             unsigned long *offset,
3890                             char **modname,
3891                             char *namebuf)
3892 {
3893         const char *ret = NULL;
3894         struct module *mod;
3895 
3896         preempt_disable();
3897         mod = __module_address(addr);
3898         if (mod) {
3899                 if (modname)
3900                         *modname = mod->name;
3901                 ret = get_ksymbol(mod, addr, size, offset);
3902         }
3903         /* Make a copy in here where it's safe */
3904         if (ret) {
3905                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3906                 ret = namebuf;
3907         }
3908         preempt_enable();
3909 
3910         return ret;
3911 }
3912 
3913 int lookup_module_symbol_name(unsigned long addr, char *symname)
3914 {
3915         struct module *mod;
3916 
3917         preempt_disable();
3918         list_for_each_entry_rcu(mod, &modules, list) {
3919                 if (mod->state == MODULE_STATE_UNFORMED)
3920                         continue;
3921                 if (within_module(addr, mod)) {
3922                         const char *sym;
3923 
3924                         sym = get_ksymbol(mod, addr, NULL, NULL);
3925                         if (!sym)
3926                                 goto out;
3927                         strlcpy(symname, sym, KSYM_NAME_LEN);
3928                         preempt_enable();
3929                         return 0;
3930                 }
3931         }
3932 out:
3933         preempt_enable();
3934         return -ERANGE;
3935 }
3936 
3937 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3938                         unsigned long *offset, char *modname, char *name)
3939 {
3940         struct module *mod;
3941 
3942         preempt_disable();
3943         list_for_each_entry_rcu(mod, &modules, list) {
3944                 if (mod->state == MODULE_STATE_UNFORMED)
3945                         continue;
3946                 if (within_module(addr, mod)) {
3947                         const char *sym;
3948 
3949                         sym = get_ksymbol(mod, addr, size, offset);
3950                         if (!sym)
3951                                 goto out;
3952                         if (modname)
3953                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3954                         if (name)
3955                                 strlcpy(name, sym, KSYM_NAME_LEN);
3956                         preempt_enable();
3957                         return 0;
3958                 }
3959         }
3960 out:
3961         preempt_enable();
3962         return -ERANGE;
3963 }
3964 
3965 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3966                         char *name, char *module_name, int *exported)
3967 {
3968         struct module *mod;
3969 
3970         preempt_disable();
3971         list_for_each_entry_rcu(mod, &modules, list) {
3972                 struct mod_kallsyms *kallsyms;
3973 
3974                 if (mod->state == MODULE_STATE_UNFORMED)
3975                         continue;
3976                 kallsyms = rcu_dereference_sched(mod->kallsyms);
3977                 if (symnum < kallsyms->num_symtab) {
3978                         *value = kallsyms->symtab[symnum].st_value;
3979                         *type = kallsyms->symtab[symnum].st_info;
3980                         strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
3981                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3982                         *exported = is_exported(name, *value, mod);
3983                         preempt_enable();
3984                         return 0;
3985                 }
3986                 symnum -= kallsyms->num_symtab;
3987         }
3988         preempt_enable();
3989         return -ERANGE;
3990 }
3991 
3992 static unsigned long mod_find_symname(struct module *mod, const char *name)
3993 {
3994         unsigned int i;
3995         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3996 
3997         for (i = 0; i < kallsyms->num_symtab; i++)
3998                 if (strcmp(name, symname(kallsyms, i)) == 0 &&
3999                     kallsyms->symtab[i].st_info != 'U')
4000                         return kallsyms->symtab[i].st_value;
4001         return 0;
4002 }
4003 
4004 /* Look for this name: can be of form module:name. */
4005 unsigned long module_kallsyms_lookup_name(const char *name)
4006 {
4007         struct module *mod;
4008         char *colon;
4009         unsigned long ret = 0;
4010 
4011         /* Don't lock: we're in enough trouble already. */
4012         preempt_disable();
4013         if ((colon = strchr(name, ':')) != NULL) {
4014                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4015                         ret = mod_find_symname(mod, colon+1);
4016         } else {
4017                 list_for_each_entry_rcu(mod, &modules, list) {
4018                         if (mod->state == MODULE_STATE_UNFORMED)
4019                                 continue;
4020                         if ((ret = mod_find_symname(mod, name)) != 0)
4021                                 break;
4022                 }
4023         }
4024         preempt_enable();
4025         return ret;
4026 }
4027 
4028 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4029                                              struct module *, unsigned long),
4030                                    void *data)
4031 {
4032         struct module *mod;
4033         unsigned int i;
4034         int ret;
4035 
4036         module_assert_mutex();
4037 
4038         list_for_each_entry(mod, &modules, list) {
4039                 /* We hold module_mutex: no need for rcu_dereference_sched */
4040                 struct mod_kallsyms *kallsyms = mod->kallsyms;
4041 
4042                 if (mod->state == MODULE_STATE_UNFORMED)
4043                         continue;
4044                 for (i = 0; i < kallsyms->num_symtab; i++) {
4045                         ret = fn(data, symname(kallsyms, i),
4046                                  mod, kallsyms->symtab[i].st_value);
4047                         if (ret != 0)
4048                                 return ret;
4049                 }
4050         }
4051         return 0;
4052 }
4053 #endif /* CONFIG_KALLSYMS */
4054 
4055 /* Maximum number of characters written by module_flags() */
4056 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4057 
4058 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4059 static char *module_flags(struct module *mod, char *buf)
4060 {
4061         int bx = 0;
4062 
4063         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4064         if (mod->taints ||
4065             mod->state == MODULE_STATE_GOING ||
4066             mod->state == MODULE_STATE_COMING) {
4067                 buf[bx++] = '(';
4068                 bx += module_flags_taint(mod, buf + bx);
4069                 /* Show a - for module-is-being-unloaded */
4070                 if (mod->state == MODULE_STATE_GOING)
4071                         buf[bx++] = '-';
4072                 /* Show a + for module-is-being-loaded */
4073                 if (mod->state == MODULE_STATE_COMING)
4074                         buf[bx++] = '+';
4075                 buf[bx++] = ')';
4076         }
4077         buf[bx] = '\0';
4078 
4079         return buf;
4080 }
4081 
4082 #ifdef CONFIG_PROC_FS
4083 /* Called by the /proc file system to return a list of modules. */
4084 static void *m_start(struct seq_file *m, loff_t *pos)
4085 {
4086         mutex_lock(&module_mutex);
4087         return seq_list_start(&modules, *pos);
4088 }
4089 
4090 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4091 {
4092         return seq_list_next(p, &modules, pos);
4093 }
4094 
4095 static void m_stop(struct seq_file *m, void *p)
4096 {
4097         mutex_unlock(&module_mutex);
4098 }
4099 
4100 static int m_show(struct seq_file *m, void *p)
4101 {
4102         struct module *mod = list_entry(p, struct module, list);
4103         char buf[MODULE_FLAGS_BUF_SIZE];
4104 
4105         /* We always ignore unformed modules. */
4106         if (mod->state == MODULE_STATE_UNFORMED)
4107                 return 0;
4108 
4109         seq_printf(m, "%s %u",
4110                    mod->name, mod->init_layout.size + mod->core_layout.size);
4111         print_unload_info(m, mod);
4112 
4113         /* Informative for users. */
4114         seq_printf(m, " %s",
4115                    mod->state == MODULE_STATE_GOING ? "Unloading" :
4116                    mod->state == MODULE_STATE_COMING ? "Loading" :
4117                    "Live");
4118         /* Used by oprofile and other similar tools. */
4119         seq_printf(m, " 0x%pK", mod->core_layout.base);
4120 
4121         /* Taints info */
4122         if (mod->taints)
4123                 seq_printf(m, " %s", module_flags(mod, buf));
4124 
4125         seq_puts(m, "\n");
4126         return 0;
4127 }
4128 
4129 /* Format: modulename size refcount deps address
4130 
4131    Where refcount is a number or -, and deps is a comma-separated list
4132    of depends or -.
4133 */
4134 static const struct seq_operations modules_op = {
4135         .start  = m_start,
4136         .next   = m_next,
4137         .stop   = m_stop,
4138         .show   = m_show
4139 };
4140 
4141 static int modules_open(struct inode *inode, struct file *file)
4142 {
4143         return seq_open(file, &modules_op);
4144 }
4145 
4146 static const struct file_operations proc_modules_operations = {
4147         .open           = modules_open,
4148         .read           = seq_read,
4149         .llseek         = seq_lseek,
4150         .release        = seq_release,
4151 };
4152 
4153 static int __init proc_modules_init(void)
4154 {
4155         proc_create("modules", 0, NULL, &proc_modules_operations);
4156         return 0;
4157 }
4158 module_init(proc_modules_init);
4159 #endif
4160 
4161 /* Given an address, look for it in the module exception tables. */
4162 const struct exception_table_entry *search_module_extables(unsigned long addr)
4163 {
4164         const struct exception_table_entry *e = NULL;
4165         struct module *mod;
4166 
4167         preempt_disable();
4168         list_for_each_entry_rcu(mod, &modules, list) {
4169                 if (mod->state == MODULE_STATE_UNFORMED)
4170                         continue;
4171                 if (mod->num_exentries == 0)
4172                         continue;
4173 
4174                 e = search_extable(mod->extable,
4175                                    mod->extable + mod->num_exentries - 1,
4176                                    addr);
4177                 if (e)
4178                         break;
4179         }
4180         preempt_enable();
4181 
4182         /* Now, if we found one, we are running inside it now, hence
4183            we cannot unload the module, hence no refcnt needed. */
4184         return e;
4185 }
4186 
4187 /*
4188  * is_module_address - is this address inside a module?
4189  * @addr: the address to check.
4190  *
4191  * See is_module_text_address() if you simply want to see if the address
4192  * is code (not data).
4193  */
4194 bool is_module_address(unsigned long addr)
4195 {
4196         bool ret;
4197 
4198         preempt_disable();
4199         ret = __module_address(addr) != NULL;
4200         preempt_enable();
4201 
4202         return ret;
4203 }
4204 
4205 /*
4206  * __module_address - get the module which contains an address.
4207  * @addr: the address.
4208  *
4209  * Must be called with preempt disabled or module mutex held so that
4210  * module doesn't get freed during this.
4211  */
4212 struct module *__module_address(unsigned long addr)
4213 {
4214         struct module *mod;
4215 
4216         if (addr < module_addr_min || addr > module_addr_max)
4217                 return NULL;
4218 
4219         module_assert_mutex_or_preempt();
4220 
4221         mod = mod_find(addr);
4222         if (mod) {
4223                 BUG_ON(!within_module(addr, mod));
4224                 if (mod->state == MODULE_STATE_UNFORMED)
4225                         mod = NULL;
4226         }
4227         return mod;
4228 }
4229 EXPORT_SYMBOL_GPL(__module_address);
4230 
4231 /*
4232  * is_module_text_address - is this address inside module code?
4233  * @addr: the address to check.
4234  *
4235  * See is_module_address() if you simply want to see if the address is
4236  * anywhere in a module.  See kernel_text_address() for testing if an
4237  * address corresponds to kernel or module code.
4238  */
4239 bool is_module_text_address(unsigned long addr)
4240 {
4241         bool ret;
4242 
4243         preempt_disable();
4244         ret = __module_text_address(addr) != NULL;
4245         preempt_enable();
4246 
4247         return ret;
4248 }
4249 
4250 /*
4251  * __module_text_address - get the module whose code contains an address.
4252  * @addr: the address.
4253  *
4254  * Must be called with preempt disabled or module mutex held so that
4255  * module doesn't get freed during this.
4256  */
4257 struct module *__module_text_address(unsigned long addr)
4258 {
4259         struct module *mod = __module_address(addr);
4260         if (mod) {
4261                 /* Make sure it's within the text section. */
4262                 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4263                     && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4264                         mod = NULL;
4265         }
4266         return mod;
4267 }
4268 EXPORT_SYMBOL_GPL(__module_text_address);
4269 
4270 /* Don't grab lock, we're oopsing. */
4271 void print_modules(void)
4272 {
4273         struct module *mod;
4274         char buf[MODULE_FLAGS_BUF_SIZE];
4275 
4276         printk(KERN_DEFAULT "Modules linked in:");
4277         /* Most callers should already have preempt disabled, but make sure */
4278         preempt_disable();
4279         list_for_each_entry_rcu(mod, &modules, list) {
4280                 if (mod->state == MODULE_STATE_UNFORMED)
4281                         continue;
4282                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4283         }
4284         preempt_enable();
4285         if (last_unloaded_module[0])
4286                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4287         pr_cont("\n");
4288 }
4289 
4290 #ifdef CONFIG_MODVERSIONS
4291 /* Generate the signature for all relevant module structures here.
4292  * If these change, we don't want to try to parse the module. */
4293 void module_layout(struct module *mod,
4294                    struct modversion_info *ver,
4295                    struct kernel_param *kp,
4296                    struct kernel_symbol *ks,
4297                    struct tracepoint * const *tp)
4298 {
4299 }
4300 EXPORT_SYMBOL(module_layout);
4301 #endif
4302 

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