Version:  2.0.40 2.2.26 2.4.37 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9

Linux/kernel/module.c

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

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