Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

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/ftrace_event.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/stop_machine.h>
 46 #include <linux/device.h>
 47 #include <linux/string.h>
 48 #include <linux/mutex.h>
 49 #include <linux/rculist.h>
 50 #include <asm/uaccess.h>
 51 #include <asm/cacheflush.h>
 52 #include <asm/mmu_context.h>
 53 #include <linux/license.h>
 54 #include <asm/sections.h>
 55 #include <linux/tracepoint.h>
 56 #include <linux/ftrace.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/fips.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 /*
 86  * Given BASE and SIZE this macro calculates the number of pages the
 87  * memory regions occupies
 88  */
 89 #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?         \
 90                 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
 91                          PFN_DOWN((unsigned long)BASE) + 1)     \
 92                 : (0UL))
 93 
 94 /* If this is set, the section belongs in the init part of the module */
 95 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
 96 
 97 /*
 98  * Mutex protects:
 99  * 1) List of modules (also safely readable with preempt_disable),
100  * 2) module_use links,
101  * 3) module_addr_min/module_addr_max.
102  * (delete uses stop_machine/add uses RCU list operations). */
103 DEFINE_MUTEX(module_mutex);
104 EXPORT_SYMBOL_GPL(module_mutex);
105 static LIST_HEAD(modules);
106 #ifdef CONFIG_KGDB_KDB
107 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
108 #endif /* CONFIG_KGDB_KDB */
109 
110 #ifdef CONFIG_MODULE_SIG
111 #ifdef CONFIG_MODULE_SIG_FORCE
112 static bool sig_enforce = true;
113 #else
114 static bool sig_enforce = false;
115 
116 static int param_set_bool_enable_only(const char *val,
117                                       const struct kernel_param *kp)
118 {
119         int err;
120         bool test;
121         struct kernel_param dummy_kp = *kp;
122 
123         dummy_kp.arg = &test;
124 
125         err = param_set_bool(val, &dummy_kp);
126         if (err)
127                 return err;
128 
129         /* Don't let them unset it once it's set! */
130         if (!test && sig_enforce)
131                 return -EROFS;
132 
133         if (test)
134                 sig_enforce = true;
135         return 0;
136 }
137 
138 static const struct kernel_param_ops param_ops_bool_enable_only = {
139         .flags = KERNEL_PARAM_FL_NOARG,
140         .set = param_set_bool_enable_only,
141         .get = param_get_bool,
142 };
143 #define param_check_bool_enable_only param_check_bool
144 
145 module_param(sig_enforce, bool_enable_only, 0644);
146 #endif /* !CONFIG_MODULE_SIG_FORCE */
147 #endif /* CONFIG_MODULE_SIG */
148 
149 /* Block module loading/unloading? */
150 int modules_disabled = 0;
151 core_param(nomodule, modules_disabled, bint, 0);
152 
153 /* Waiting for a module to finish initializing? */
154 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
155 
156 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
157 
158 /* Bounds of module allocation, for speeding __module_address.
159  * Protected by module_mutex. */
160 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
161 
162 int register_module_notifier(struct notifier_block * nb)
163 {
164         return blocking_notifier_chain_register(&module_notify_list, nb);
165 }
166 EXPORT_SYMBOL(register_module_notifier);
167 
168 int unregister_module_notifier(struct notifier_block * nb)
169 {
170         return blocking_notifier_chain_unregister(&module_notify_list, nb);
171 }
172 EXPORT_SYMBOL(unregister_module_notifier);
173 
174 struct load_info {
175         Elf_Ehdr *hdr;
176         unsigned long len;
177         Elf_Shdr *sechdrs;
178         char *secstrings, *strtab;
179         unsigned long symoffs, stroffs;
180         struct _ddebug *debug;
181         unsigned int num_debug;
182         bool sig_ok;
183         struct {
184                 unsigned int sym, str, mod, vers, info, pcpu;
185         } index;
186 };
187 
188 /* We require a truly strong try_module_get(): 0 means failure due to
189    ongoing or failed initialization etc. */
190 static inline int strong_try_module_get(struct module *mod)
191 {
192         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
193         if (mod && mod->state == MODULE_STATE_COMING)
194                 return -EBUSY;
195         if (try_module_get(mod))
196                 return 0;
197         else
198                 return -ENOENT;
199 }
200 
201 static inline void add_taint_module(struct module *mod, unsigned flag,
202                                     enum lockdep_ok lockdep_ok)
203 {
204         add_taint(flag, lockdep_ok);
205         mod->taints |= (1U << flag);
206 }
207 
208 /*
209  * A thread that wants to hold a reference to a module only while it
210  * is running can call this to safely exit.  nfsd and lockd use this.
211  */
212 void __module_put_and_exit(struct module *mod, long code)
213 {
214         module_put(mod);
215         do_exit(code);
216 }
217 EXPORT_SYMBOL(__module_put_and_exit);
218 
219 /* Find a module section: 0 means not found. */
220 static unsigned int find_sec(const struct load_info *info, const char *name)
221 {
222         unsigned int i;
223 
224         for (i = 1; i < info->hdr->e_shnum; i++) {
225                 Elf_Shdr *shdr = &info->sechdrs[i];
226                 /* Alloc bit cleared means "ignore it." */
227                 if ((shdr->sh_flags & SHF_ALLOC)
228                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
229                         return i;
230         }
231         return 0;
232 }
233 
234 /* Find a module section, or NULL. */
235 static void *section_addr(const struct load_info *info, const char *name)
236 {
237         /* Section 0 has sh_addr 0. */
238         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
239 }
240 
241 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
242 static void *section_objs(const struct load_info *info,
243                           const char *name,
244                           size_t object_size,
245                           unsigned int *num)
246 {
247         unsigned int sec = find_sec(info, name);
248 
249         /* Section 0 has sh_addr 0 and sh_size 0. */
250         *num = info->sechdrs[sec].sh_size / object_size;
251         return (void *)info->sechdrs[sec].sh_addr;
252 }
253 
254 /* Provided by the linker */
255 extern const struct kernel_symbol __start___ksymtab[];
256 extern const struct kernel_symbol __stop___ksymtab[];
257 extern const struct kernel_symbol __start___ksymtab_gpl[];
258 extern const struct kernel_symbol __stop___ksymtab_gpl[];
259 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
260 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
261 extern const unsigned long __start___kcrctab[];
262 extern const unsigned long __start___kcrctab_gpl[];
263 extern const unsigned long __start___kcrctab_gpl_future[];
264 #ifdef CONFIG_UNUSED_SYMBOLS
265 extern const struct kernel_symbol __start___ksymtab_unused[];
266 extern const struct kernel_symbol __stop___ksymtab_unused[];
267 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
268 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
269 extern const unsigned long __start___kcrctab_unused[];
270 extern const unsigned long __start___kcrctab_unused_gpl[];
271 #endif
272 
273 #ifndef CONFIG_MODVERSIONS
274 #define symversion(base, idx) NULL
275 #else
276 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
277 #endif
278 
279 static bool each_symbol_in_section(const struct symsearch *arr,
280                                    unsigned int arrsize,
281                                    struct module *owner,
282                                    bool (*fn)(const struct symsearch *syms,
283                                               struct module *owner,
284                                               void *data),
285                                    void *data)
286 {
287         unsigned int j;
288 
289         for (j = 0; j < arrsize; j++) {
290                 if (fn(&arr[j], owner, data))
291                         return true;
292         }
293 
294         return false;
295 }
296 
297 /* Returns true as soon as fn returns true, otherwise false. */
298 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
299                                     struct module *owner,
300                                     void *data),
301                          void *data)
302 {
303         struct module *mod;
304         static const struct symsearch arr[] = {
305                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
306                   NOT_GPL_ONLY, false },
307                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
308                   __start___kcrctab_gpl,
309                   GPL_ONLY, false },
310                 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
311                   __start___kcrctab_gpl_future,
312                   WILL_BE_GPL_ONLY, false },
313 #ifdef CONFIG_UNUSED_SYMBOLS
314                 { __start___ksymtab_unused, __stop___ksymtab_unused,
315                   __start___kcrctab_unused,
316                   NOT_GPL_ONLY, true },
317                 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
318                   __start___kcrctab_unused_gpl,
319                   GPL_ONLY, true },
320 #endif
321         };
322 
323         if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
324                 return true;
325 
326         list_for_each_entry_rcu(mod, &modules, list) {
327                 struct symsearch arr[] = {
328                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
329                           NOT_GPL_ONLY, false },
330                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
331                           mod->gpl_crcs,
332                           GPL_ONLY, false },
333                         { mod->gpl_future_syms,
334                           mod->gpl_future_syms + mod->num_gpl_future_syms,
335                           mod->gpl_future_crcs,
336                           WILL_BE_GPL_ONLY, false },
337 #ifdef CONFIG_UNUSED_SYMBOLS
338                         { mod->unused_syms,
339                           mod->unused_syms + mod->num_unused_syms,
340                           mod->unused_crcs,
341                           NOT_GPL_ONLY, true },
342                         { mod->unused_gpl_syms,
343                           mod->unused_gpl_syms + mod->num_unused_gpl_syms,
344                           mod->unused_gpl_crcs,
345                           GPL_ONLY, true },
346 #endif
347                 };
348 
349                 if (mod->state == MODULE_STATE_UNFORMED)
350                         continue;
351 
352                 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
353                         return true;
354         }
355         return false;
356 }
357 EXPORT_SYMBOL_GPL(each_symbol_section);
358 
359 struct find_symbol_arg {
360         /* Input */
361         const char *name;
362         bool gplok;
363         bool warn;
364 
365         /* Output */
366         struct module *owner;
367         const unsigned long *crc;
368         const struct kernel_symbol *sym;
369 };
370 
371 static bool check_symbol(const struct symsearch *syms,
372                                  struct module *owner,
373                                  unsigned int symnum, void *data)
374 {
375         struct find_symbol_arg *fsa = data;
376 
377         if (!fsa->gplok) {
378                 if (syms->licence == GPL_ONLY)
379                         return false;
380                 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
381                         pr_warn("Symbol %s is being used by a non-GPL module, "
382                                 "which will not be allowed in the future\n",
383                                 fsa->name);
384                 }
385         }
386 
387 #ifdef CONFIG_UNUSED_SYMBOLS
388         if (syms->unused && fsa->warn) {
389                 pr_warn("Symbol %s is marked as UNUSED, however this module is "
390                         "using it.\n", fsa->name);
391                 pr_warn("This symbol will go away in the future.\n");
392                 pr_warn("Please evalute if this is the right api to use and if "
393                         "it really is, submit a report the linux kernel "
394                         "mailinglist together with submitting your code for "
395                         "inclusion.\n");
396         }
397 #endif
398 
399         fsa->owner = owner;
400         fsa->crc = symversion(syms->crcs, symnum);
401         fsa->sym = &syms->start[symnum];
402         return true;
403 }
404 
405 static int cmp_name(const void *va, const void *vb)
406 {
407         const char *a;
408         const struct kernel_symbol *b;
409         a = va; b = vb;
410         return strcmp(a, b->name);
411 }
412 
413 static bool find_symbol_in_section(const struct symsearch *syms,
414                                    struct module *owner,
415                                    void *data)
416 {
417         struct find_symbol_arg *fsa = data;
418         struct kernel_symbol *sym;
419 
420         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
421                         sizeof(struct kernel_symbol), cmp_name);
422 
423         if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
424                 return true;
425 
426         return false;
427 }
428 
429 /* Find a symbol and return it, along with, (optional) crc and
430  * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
431 const struct kernel_symbol *find_symbol(const char *name,
432                                         struct module **owner,
433                                         const unsigned long **crc,
434                                         bool gplok,
435                                         bool warn)
436 {
437         struct find_symbol_arg fsa;
438 
439         fsa.name = name;
440         fsa.gplok = gplok;
441         fsa.warn = warn;
442 
443         if (each_symbol_section(find_symbol_in_section, &fsa)) {
444                 if (owner)
445                         *owner = fsa.owner;
446                 if (crc)
447                         *crc = fsa.crc;
448                 return fsa.sym;
449         }
450 
451         pr_debug("Failed to find symbol %s\n", name);
452         return NULL;
453 }
454 EXPORT_SYMBOL_GPL(find_symbol);
455 
456 /* Search for module by name: must hold module_mutex. */
457 static struct module *find_module_all(const char *name, size_t len,
458                                       bool even_unformed)
459 {
460         struct module *mod;
461 
462         list_for_each_entry(mod, &modules, list) {
463                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
464                         continue;
465                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
466                         return mod;
467         }
468         return NULL;
469 }
470 
471 struct module *find_module(const char *name)
472 {
473         return find_module_all(name, strlen(name), false);
474 }
475 EXPORT_SYMBOL_GPL(find_module);
476 
477 #ifdef CONFIG_SMP
478 
479 static inline void __percpu *mod_percpu(struct module *mod)
480 {
481         return mod->percpu;
482 }
483 
484 static int percpu_modalloc(struct module *mod, struct load_info *info)
485 {
486         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
487         unsigned long align = pcpusec->sh_addralign;
488 
489         if (!pcpusec->sh_size)
490                 return 0;
491 
492         if (align > PAGE_SIZE) {
493                 pr_warn("%s: per-cpu alignment %li > %li\n",
494                         mod->name, align, PAGE_SIZE);
495                 align = PAGE_SIZE;
496         }
497 
498         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
499         if (!mod->percpu) {
500                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
501                         mod->name, (unsigned long)pcpusec->sh_size);
502                 return -ENOMEM;
503         }
504         mod->percpu_size = pcpusec->sh_size;
505         return 0;
506 }
507 
508 static void percpu_modfree(struct module *mod)
509 {
510         free_percpu(mod->percpu);
511 }
512 
513 static unsigned int find_pcpusec(struct load_info *info)
514 {
515         return find_sec(info, ".data..percpu");
516 }
517 
518 static void percpu_modcopy(struct module *mod,
519                            const void *from, unsigned long size)
520 {
521         int cpu;
522 
523         for_each_possible_cpu(cpu)
524                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
525 }
526 
527 /**
528  * is_module_percpu_address - test whether address is from module static percpu
529  * @addr: address to test
530  *
531  * Test whether @addr belongs to module static percpu area.
532  *
533  * RETURNS:
534  * %true if @addr is from module static percpu area
535  */
536 bool is_module_percpu_address(unsigned long addr)
537 {
538         struct module *mod;
539         unsigned int cpu;
540 
541         preempt_disable();
542 
543         list_for_each_entry_rcu(mod, &modules, list) {
544                 if (mod->state == MODULE_STATE_UNFORMED)
545                         continue;
546                 if (!mod->percpu_size)
547                         continue;
548                 for_each_possible_cpu(cpu) {
549                         void *start = per_cpu_ptr(mod->percpu, cpu);
550 
551                         if ((void *)addr >= start &&
552                             (void *)addr < start + mod->percpu_size) {
553                                 preempt_enable();
554                                 return true;
555                         }
556                 }
557         }
558 
559         preempt_enable();
560         return false;
561 }
562 
563 #else /* ... !CONFIG_SMP */
564 
565 static inline void __percpu *mod_percpu(struct module *mod)
566 {
567         return NULL;
568 }
569 static int percpu_modalloc(struct module *mod, struct load_info *info)
570 {
571         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
572         if (info->sechdrs[info->index.pcpu].sh_size != 0)
573                 return -ENOMEM;
574         return 0;
575 }
576 static inline void percpu_modfree(struct module *mod)
577 {
578 }
579 static unsigned int find_pcpusec(struct load_info *info)
580 {
581         return 0;
582 }
583 static inline void percpu_modcopy(struct module *mod,
584                                   const void *from, unsigned long size)
585 {
586         /* pcpusec should be 0, and size of that section should be 0. */
587         BUG_ON(size != 0);
588 }
589 bool is_module_percpu_address(unsigned long addr)
590 {
591         return false;
592 }
593 
594 #endif /* CONFIG_SMP */
595 
596 #define MODINFO_ATTR(field)     \
597 static void setup_modinfo_##field(struct module *mod, const char *s)  \
598 {                                                                     \
599         mod->field = kstrdup(s, GFP_KERNEL);                          \
600 }                                                                     \
601 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
602                         struct module_kobject *mk, char *buffer)      \
603 {                                                                     \
604         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
605 }                                                                     \
606 static int modinfo_##field##_exists(struct module *mod)               \
607 {                                                                     \
608         return mod->field != NULL;                                    \
609 }                                                                     \
610 static void free_modinfo_##field(struct module *mod)                  \
611 {                                                                     \
612         kfree(mod->field);                                            \
613         mod->field = NULL;                                            \
614 }                                                                     \
615 static struct module_attribute modinfo_##field = {                    \
616         .attr = { .name = __stringify(field), .mode = 0444 },         \
617         .show = show_modinfo_##field,                                 \
618         .setup = setup_modinfo_##field,                               \
619         .test = modinfo_##field##_exists,                             \
620         .free = free_modinfo_##field,                                 \
621 };
622 
623 MODINFO_ATTR(version);
624 MODINFO_ATTR(srcversion);
625 
626 static char last_unloaded_module[MODULE_NAME_LEN+1];
627 
628 #ifdef CONFIG_MODULE_UNLOAD
629 
630 EXPORT_TRACEPOINT_SYMBOL(module_get);
631 
632 /* Init the unload section of the module. */
633 static int module_unload_init(struct module *mod)
634 {
635         mod->refptr = alloc_percpu(struct module_ref);
636         if (!mod->refptr)
637                 return -ENOMEM;
638 
639         INIT_LIST_HEAD(&mod->source_list);
640         INIT_LIST_HEAD(&mod->target_list);
641 
642         /* Hold reference count during initialization. */
643         raw_cpu_write(mod->refptr->incs, 1);
644 
645         return 0;
646 }
647 
648 /* Does a already use b? */
649 static int already_uses(struct module *a, struct module *b)
650 {
651         struct module_use *use;
652 
653         list_for_each_entry(use, &b->source_list, source_list) {
654                 if (use->source == a) {
655                         pr_debug("%s uses %s!\n", a->name, b->name);
656                         return 1;
657                 }
658         }
659         pr_debug("%s does not use %s!\n", a->name, b->name);
660         return 0;
661 }
662 
663 /*
664  * Module a uses b
665  *  - we add 'a' as a "source", 'b' as a "target" of module use
666  *  - the module_use is added to the list of 'b' sources (so
667  *    'b' can walk the list to see who sourced them), and of 'a'
668  *    targets (so 'a' can see what modules it targets).
669  */
670 static int add_module_usage(struct module *a, struct module *b)
671 {
672         struct module_use *use;
673 
674         pr_debug("Allocating new usage for %s.\n", a->name);
675         use = kmalloc(sizeof(*use), GFP_ATOMIC);
676         if (!use) {
677                 pr_warn("%s: out of memory loading\n", a->name);
678                 return -ENOMEM;
679         }
680 
681         use->source = a;
682         use->target = b;
683         list_add(&use->source_list, &b->source_list);
684         list_add(&use->target_list, &a->target_list);
685         return 0;
686 }
687 
688 /* Module a uses b: caller needs module_mutex() */
689 int ref_module(struct module *a, struct module *b)
690 {
691         int err;
692 
693         if (b == NULL || already_uses(a, b))
694                 return 0;
695 
696         /* If module isn't available, we fail. */
697         err = strong_try_module_get(b);
698         if (err)
699                 return err;
700 
701         err = add_module_usage(a, b);
702         if (err) {
703                 module_put(b);
704                 return err;
705         }
706         return 0;
707 }
708 EXPORT_SYMBOL_GPL(ref_module);
709 
710 /* Clear the unload stuff of the module. */
711 static void module_unload_free(struct module *mod)
712 {
713         struct module_use *use, *tmp;
714 
715         mutex_lock(&module_mutex);
716         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
717                 struct module *i = use->target;
718                 pr_debug("%s unusing %s\n", mod->name, i->name);
719                 module_put(i);
720                 list_del(&use->source_list);
721                 list_del(&use->target_list);
722                 kfree(use);
723         }
724         mutex_unlock(&module_mutex);
725 
726         free_percpu(mod->refptr);
727 }
728 
729 #ifdef CONFIG_MODULE_FORCE_UNLOAD
730 static inline int try_force_unload(unsigned int flags)
731 {
732         int ret = (flags & O_TRUNC);
733         if (ret)
734                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
735         return ret;
736 }
737 #else
738 static inline int try_force_unload(unsigned int flags)
739 {
740         return 0;
741 }
742 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
743 
744 struct stopref
745 {
746         struct module *mod;
747         int flags;
748         int *forced;
749 };
750 
751 /* Whole machine is stopped with interrupts off when this runs. */
752 static int __try_stop_module(void *_sref)
753 {
754         struct stopref *sref = _sref;
755 
756         /* If it's not unused, quit unless we're forcing. */
757         if (module_refcount(sref->mod) != 0) {
758                 if (!(*sref->forced = try_force_unload(sref->flags)))
759                         return -EWOULDBLOCK;
760         }
761 
762         /* Mark it as dying. */
763         sref->mod->state = MODULE_STATE_GOING;
764         return 0;
765 }
766 
767 static int try_stop_module(struct module *mod, int flags, int *forced)
768 {
769         struct stopref sref = { mod, flags, forced };
770 
771         return stop_machine(__try_stop_module, &sref, NULL);
772 }
773 
774 unsigned long module_refcount(struct module *mod)
775 {
776         unsigned long incs = 0, decs = 0;
777         int cpu;
778 
779         for_each_possible_cpu(cpu)
780                 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
781         /*
782          * ensure the incs are added up after the decs.
783          * module_put ensures incs are visible before decs with smp_wmb.
784          *
785          * This 2-count scheme avoids the situation where the refcount
786          * for CPU0 is read, then CPU0 increments the module refcount,
787          * then CPU1 drops that refcount, then the refcount for CPU1 is
788          * read. We would record a decrement but not its corresponding
789          * increment so we would see a low count (disaster).
790          *
791          * Rare situation? But module_refcount can be preempted, and we
792          * might be tallying up 4096+ CPUs. So it is not impossible.
793          */
794         smp_rmb();
795         for_each_possible_cpu(cpu)
796                 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
797         return incs - decs;
798 }
799 EXPORT_SYMBOL(module_refcount);
800 
801 /* This exists whether we can unload or not */
802 static void free_module(struct module *mod);
803 
804 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
805                 unsigned int, flags)
806 {
807         struct module *mod;
808         char name[MODULE_NAME_LEN];
809         int ret, forced = 0;
810 
811         if (!capable(CAP_SYS_MODULE) || modules_disabled)
812                 return -EPERM;
813 
814         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
815                 return -EFAULT;
816         name[MODULE_NAME_LEN-1] = '\0';
817 
818         if (mutex_lock_interruptible(&module_mutex) != 0)
819                 return -EINTR;
820 
821         mod = find_module(name);
822         if (!mod) {
823                 ret = -ENOENT;
824                 goto out;
825         }
826 
827         if (!list_empty(&mod->source_list)) {
828                 /* Other modules depend on us: get rid of them first. */
829                 ret = -EWOULDBLOCK;
830                 goto out;
831         }
832 
833         /* Doing init or already dying? */
834         if (mod->state != MODULE_STATE_LIVE) {
835                 /* FIXME: if (force), slam module count damn the torpedoes */
836                 pr_debug("%s already dying\n", mod->name);
837                 ret = -EBUSY;
838                 goto out;
839         }
840 
841         /* If it has an init func, it must have an exit func to unload */
842         if (mod->init && !mod->exit) {
843                 forced = try_force_unload(flags);
844                 if (!forced) {
845                         /* This module can't be removed */
846                         ret = -EBUSY;
847                         goto out;
848                 }
849         }
850 
851         /* Stop the machine so refcounts can't move and disable module. */
852         ret = try_stop_module(mod, flags, &forced);
853         if (ret != 0)
854                 goto out;
855 
856         mutex_unlock(&module_mutex);
857         /* Final destruction now no one is using it. */
858         if (mod->exit != NULL)
859                 mod->exit();
860         blocking_notifier_call_chain(&module_notify_list,
861                                      MODULE_STATE_GOING, mod);
862         async_synchronize_full();
863 
864         /* Store the name of the last unloaded module for diagnostic purposes */
865         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
866 
867         free_module(mod);
868         return 0;
869 out:
870         mutex_unlock(&module_mutex);
871         return ret;
872 }
873 
874 static inline void print_unload_info(struct seq_file *m, struct module *mod)
875 {
876         struct module_use *use;
877         int printed_something = 0;
878 
879         seq_printf(m, " %lu ", module_refcount(mod));
880 
881         /* Always include a trailing , so userspace can differentiate
882            between this and the old multi-field proc format. */
883         list_for_each_entry(use, &mod->source_list, source_list) {
884                 printed_something = 1;
885                 seq_printf(m, "%s,", use->source->name);
886         }
887 
888         if (mod->init != NULL && mod->exit == NULL) {
889                 printed_something = 1;
890                 seq_printf(m, "[permanent],");
891         }
892 
893         if (!printed_something)
894                 seq_printf(m, "-");
895 }
896 
897 void __symbol_put(const char *symbol)
898 {
899         struct module *owner;
900 
901         preempt_disable();
902         if (!find_symbol(symbol, &owner, NULL, true, false))
903                 BUG();
904         module_put(owner);
905         preempt_enable();
906 }
907 EXPORT_SYMBOL(__symbol_put);
908 
909 /* Note this assumes addr is a function, which it currently always is. */
910 void symbol_put_addr(void *addr)
911 {
912         struct module *modaddr;
913         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
914 
915         if (core_kernel_text(a))
916                 return;
917 
918         /* module_text_address is safe here: we're supposed to have reference
919          * to module from symbol_get, so it can't go away. */
920         modaddr = __module_text_address(a);
921         BUG_ON(!modaddr);
922         module_put(modaddr);
923 }
924 EXPORT_SYMBOL_GPL(symbol_put_addr);
925 
926 static ssize_t show_refcnt(struct module_attribute *mattr,
927                            struct module_kobject *mk, char *buffer)
928 {
929         return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
930 }
931 
932 static struct module_attribute modinfo_refcnt =
933         __ATTR(refcnt, 0444, show_refcnt, NULL);
934 
935 void __module_get(struct module *module)
936 {
937         if (module) {
938                 preempt_disable();
939                 __this_cpu_inc(module->refptr->incs);
940                 trace_module_get(module, _RET_IP_);
941                 preempt_enable();
942         }
943 }
944 EXPORT_SYMBOL(__module_get);
945 
946 bool try_module_get(struct module *module)
947 {
948         bool ret = true;
949 
950         if (module) {
951                 preempt_disable();
952 
953                 if (likely(module_is_live(module))) {
954                         __this_cpu_inc(module->refptr->incs);
955                         trace_module_get(module, _RET_IP_);
956                 } else
957                         ret = false;
958 
959                 preempt_enable();
960         }
961         return ret;
962 }
963 EXPORT_SYMBOL(try_module_get);
964 
965 void module_put(struct module *module)
966 {
967         if (module) {
968                 preempt_disable();
969                 smp_wmb(); /* see comment in module_refcount */
970                 __this_cpu_inc(module->refptr->decs);
971 
972                 trace_module_put(module, _RET_IP_);
973                 preempt_enable();
974         }
975 }
976 EXPORT_SYMBOL(module_put);
977 
978 #else /* !CONFIG_MODULE_UNLOAD */
979 static inline void print_unload_info(struct seq_file *m, struct module *mod)
980 {
981         /* We don't know the usage count, or what modules are using. */
982         seq_printf(m, " - -");
983 }
984 
985 static inline void module_unload_free(struct module *mod)
986 {
987 }
988 
989 int ref_module(struct module *a, struct module *b)
990 {
991         return strong_try_module_get(b);
992 }
993 EXPORT_SYMBOL_GPL(ref_module);
994 
995 static inline int module_unload_init(struct module *mod)
996 {
997         return 0;
998 }
999 #endif /* CONFIG_MODULE_UNLOAD */
1000 
1001 static size_t module_flags_taint(struct module *mod, char *buf)
1002 {
1003         size_t l = 0;
1004 
1005         if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1006                 buf[l++] = 'P';
1007         if (mod->taints & (1 << TAINT_OOT_MODULE))
1008                 buf[l++] = 'O';
1009         if (mod->taints & (1 << TAINT_FORCED_MODULE))
1010                 buf[l++] = 'F';
1011         if (mod->taints & (1 << TAINT_CRAP))
1012                 buf[l++] = 'C';
1013         if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1014                 buf[l++] = 'E';
1015         /*
1016          * TAINT_FORCED_RMMOD: could be added.
1017          * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1018          * apply to modules.
1019          */
1020         return l;
1021 }
1022 
1023 static ssize_t show_initstate(struct module_attribute *mattr,
1024                               struct module_kobject *mk, char *buffer)
1025 {
1026         const char *state = "unknown";
1027 
1028         switch (mk->mod->state) {
1029         case MODULE_STATE_LIVE:
1030                 state = "live";
1031                 break;
1032         case MODULE_STATE_COMING:
1033                 state = "coming";
1034                 break;
1035         case MODULE_STATE_GOING:
1036                 state = "going";
1037                 break;
1038         default:
1039                 BUG();
1040         }
1041         return sprintf(buffer, "%s\n", state);
1042 }
1043 
1044 static struct module_attribute modinfo_initstate =
1045         __ATTR(initstate, 0444, show_initstate, NULL);
1046 
1047 static ssize_t store_uevent(struct module_attribute *mattr,
1048                             struct module_kobject *mk,
1049                             const char *buffer, size_t count)
1050 {
1051         enum kobject_action action;
1052 
1053         if (kobject_action_type(buffer, count, &action) == 0)
1054                 kobject_uevent(&mk->kobj, action);
1055         return count;
1056 }
1057 
1058 struct module_attribute module_uevent =
1059         __ATTR(uevent, 0200, NULL, store_uevent);
1060 
1061 static ssize_t show_coresize(struct module_attribute *mattr,
1062                              struct module_kobject *mk, char *buffer)
1063 {
1064         return sprintf(buffer, "%u\n", mk->mod->core_size);
1065 }
1066 
1067 static struct module_attribute modinfo_coresize =
1068         __ATTR(coresize, 0444, show_coresize, NULL);
1069 
1070 static ssize_t show_initsize(struct module_attribute *mattr,
1071                              struct module_kobject *mk, char *buffer)
1072 {
1073         return sprintf(buffer, "%u\n", mk->mod->init_size);
1074 }
1075 
1076 static struct module_attribute modinfo_initsize =
1077         __ATTR(initsize, 0444, show_initsize, NULL);
1078 
1079 static ssize_t show_taint(struct module_attribute *mattr,
1080                           struct module_kobject *mk, char *buffer)
1081 {
1082         size_t l;
1083 
1084         l = module_flags_taint(mk->mod, buffer);
1085         buffer[l++] = '\n';
1086         return l;
1087 }
1088 
1089 static struct module_attribute modinfo_taint =
1090         __ATTR(taint, 0444, show_taint, NULL);
1091 
1092 static struct module_attribute *modinfo_attrs[] = {
1093         &module_uevent,
1094         &modinfo_version,
1095         &modinfo_srcversion,
1096         &modinfo_initstate,
1097         &modinfo_coresize,
1098         &modinfo_initsize,
1099         &modinfo_taint,
1100 #ifdef CONFIG_MODULE_UNLOAD
1101         &modinfo_refcnt,
1102 #endif
1103         NULL,
1104 };
1105 
1106 static const char vermagic[] = VERMAGIC_STRING;
1107 
1108 static int try_to_force_load(struct module *mod, const char *reason)
1109 {
1110 #ifdef CONFIG_MODULE_FORCE_LOAD
1111         if (!test_taint(TAINT_FORCED_MODULE))
1112                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1113         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1114         return 0;
1115 #else
1116         return -ENOEXEC;
1117 #endif
1118 }
1119 
1120 #ifdef CONFIG_MODVERSIONS
1121 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1122 static unsigned long maybe_relocated(unsigned long crc,
1123                                      const struct module *crc_owner)
1124 {
1125 #ifdef ARCH_RELOCATES_KCRCTAB
1126         if (crc_owner == NULL)
1127                 return crc - (unsigned long)reloc_start;
1128 #endif
1129         return crc;
1130 }
1131 
1132 static int check_version(Elf_Shdr *sechdrs,
1133                          unsigned int versindex,
1134                          const char *symname,
1135                          struct module *mod, 
1136                          const unsigned long *crc,
1137                          const struct module *crc_owner)
1138 {
1139         unsigned int i, num_versions;
1140         struct modversion_info *versions;
1141 
1142         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1143         if (!crc)
1144                 return 1;
1145 
1146         /* No versions at all?  modprobe --force does this. */
1147         if (versindex == 0)
1148                 return try_to_force_load(mod, symname) == 0;
1149 
1150         versions = (void *) sechdrs[versindex].sh_addr;
1151         num_versions = sechdrs[versindex].sh_size
1152                 / sizeof(struct modversion_info);
1153 
1154         for (i = 0; i < num_versions; i++) {
1155                 if (strcmp(versions[i].name, symname) != 0)
1156                         continue;
1157 
1158                 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1159                         return 1;
1160                 pr_debug("Found checksum %lX vs module %lX\n",
1161                        maybe_relocated(*crc, crc_owner), versions[i].crc);
1162                 goto bad_version;
1163         }
1164 
1165         pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1166         return 0;
1167 
1168 bad_version:
1169         printk("%s: disagrees about version of symbol %s\n",
1170                mod->name, symname);
1171         return 0;
1172 }
1173 
1174 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1175                                           unsigned int versindex,
1176                                           struct module *mod)
1177 {
1178         const unsigned long *crc;
1179 
1180         /* Since this should be found in kernel (which can't be removed),
1181          * no locking is necessary. */
1182         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1183                          &crc, true, false))
1184                 BUG();
1185         return check_version(sechdrs, versindex,
1186                              VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1187                              NULL);
1188 }
1189 
1190 /* First part is kernel version, which we ignore if module has crcs. */
1191 static inline int same_magic(const char *amagic, const char *bmagic,
1192                              bool has_crcs)
1193 {
1194         if (has_crcs) {
1195                 amagic += strcspn(amagic, " ");
1196                 bmagic += strcspn(bmagic, " ");
1197         }
1198         return strcmp(amagic, bmagic) == 0;
1199 }
1200 #else
1201 static inline int check_version(Elf_Shdr *sechdrs,
1202                                 unsigned int versindex,
1203                                 const char *symname,
1204                                 struct module *mod, 
1205                                 const unsigned long *crc,
1206                                 const struct module *crc_owner)
1207 {
1208         return 1;
1209 }
1210 
1211 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1212                                           unsigned int versindex,
1213                                           struct module *mod)
1214 {
1215         return 1;
1216 }
1217 
1218 static inline int same_magic(const char *amagic, const char *bmagic,
1219                              bool has_crcs)
1220 {
1221         return strcmp(amagic, bmagic) == 0;
1222 }
1223 #endif /* CONFIG_MODVERSIONS */
1224 
1225 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1226 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1227                                                   const struct load_info *info,
1228                                                   const char *name,
1229                                                   char ownername[])
1230 {
1231         struct module *owner;
1232         const struct kernel_symbol *sym;
1233         const unsigned long *crc;
1234         int err;
1235 
1236         mutex_lock(&module_mutex);
1237         sym = find_symbol(name, &owner, &crc,
1238                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1239         if (!sym)
1240                 goto unlock;
1241 
1242         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1243                            owner)) {
1244                 sym = ERR_PTR(-EINVAL);
1245                 goto getname;
1246         }
1247 
1248         err = ref_module(mod, owner);
1249         if (err) {
1250                 sym = ERR_PTR(err);
1251                 goto getname;
1252         }
1253 
1254 getname:
1255         /* We must make copy under the lock if we failed to get ref. */
1256         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1257 unlock:
1258         mutex_unlock(&module_mutex);
1259         return sym;
1260 }
1261 
1262 static const struct kernel_symbol *
1263 resolve_symbol_wait(struct module *mod,
1264                     const struct load_info *info,
1265                     const char *name)
1266 {
1267         const struct kernel_symbol *ksym;
1268         char owner[MODULE_NAME_LEN];
1269 
1270         if (wait_event_interruptible_timeout(module_wq,
1271                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1272                         || PTR_ERR(ksym) != -EBUSY,
1273                                              30 * HZ) <= 0) {
1274                 pr_warn("%s: gave up waiting for init of module %s.\n",
1275                         mod->name, owner);
1276         }
1277         return ksym;
1278 }
1279 
1280 /*
1281  * /sys/module/foo/sections stuff
1282  * J. Corbet <corbet@lwn.net>
1283  */
1284 #ifdef CONFIG_SYSFS
1285 
1286 #ifdef CONFIG_KALLSYMS
1287 static inline bool sect_empty(const Elf_Shdr *sect)
1288 {
1289         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1290 }
1291 
1292 struct module_sect_attr
1293 {
1294         struct module_attribute mattr;
1295         char *name;
1296         unsigned long address;
1297 };
1298 
1299 struct module_sect_attrs
1300 {
1301         struct attribute_group grp;
1302         unsigned int nsections;
1303         struct module_sect_attr attrs[0];
1304 };
1305 
1306 static ssize_t module_sect_show(struct module_attribute *mattr,
1307                                 struct module_kobject *mk, char *buf)
1308 {
1309         struct module_sect_attr *sattr =
1310                 container_of(mattr, struct module_sect_attr, mattr);
1311         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1312 }
1313 
1314 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1315 {
1316         unsigned int section;
1317 
1318         for (section = 0; section < sect_attrs->nsections; section++)
1319                 kfree(sect_attrs->attrs[section].name);
1320         kfree(sect_attrs);
1321 }
1322 
1323 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1324 {
1325         unsigned int nloaded = 0, i, size[2];
1326         struct module_sect_attrs *sect_attrs;
1327         struct module_sect_attr *sattr;
1328         struct attribute **gattr;
1329 
1330         /* Count loaded sections and allocate structures */
1331         for (i = 0; i < info->hdr->e_shnum; i++)
1332                 if (!sect_empty(&info->sechdrs[i]))
1333                         nloaded++;
1334         size[0] = ALIGN(sizeof(*sect_attrs)
1335                         + nloaded * sizeof(sect_attrs->attrs[0]),
1336                         sizeof(sect_attrs->grp.attrs[0]));
1337         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1338         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1339         if (sect_attrs == NULL)
1340                 return;
1341 
1342         /* Setup section attributes. */
1343         sect_attrs->grp.name = "sections";
1344         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1345 
1346         sect_attrs->nsections = 0;
1347         sattr = &sect_attrs->attrs[0];
1348         gattr = &sect_attrs->grp.attrs[0];
1349         for (i = 0; i < info->hdr->e_shnum; i++) {
1350                 Elf_Shdr *sec = &info->sechdrs[i];
1351                 if (sect_empty(sec))
1352                         continue;
1353                 sattr->address = sec->sh_addr;
1354                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1355                                         GFP_KERNEL);
1356                 if (sattr->name == NULL)
1357                         goto out;
1358                 sect_attrs->nsections++;
1359                 sysfs_attr_init(&sattr->mattr.attr);
1360                 sattr->mattr.show = module_sect_show;
1361                 sattr->mattr.store = NULL;
1362                 sattr->mattr.attr.name = sattr->name;
1363                 sattr->mattr.attr.mode = S_IRUGO;
1364                 *(gattr++) = &(sattr++)->mattr.attr;
1365         }
1366         *gattr = NULL;
1367 
1368         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1369                 goto out;
1370 
1371         mod->sect_attrs = sect_attrs;
1372         return;
1373   out:
1374         free_sect_attrs(sect_attrs);
1375 }
1376 
1377 static void remove_sect_attrs(struct module *mod)
1378 {
1379         if (mod->sect_attrs) {
1380                 sysfs_remove_group(&mod->mkobj.kobj,
1381                                    &mod->sect_attrs->grp);
1382                 /* We are positive that no one is using any sect attrs
1383                  * at this point.  Deallocate immediately. */
1384                 free_sect_attrs(mod->sect_attrs);
1385                 mod->sect_attrs = NULL;
1386         }
1387 }
1388 
1389 /*
1390  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1391  */
1392 
1393 struct module_notes_attrs {
1394         struct kobject *dir;
1395         unsigned int notes;
1396         struct bin_attribute attrs[0];
1397 };
1398 
1399 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1400                                  struct bin_attribute *bin_attr,
1401                                  char *buf, loff_t pos, size_t count)
1402 {
1403         /*
1404          * The caller checked the pos and count against our size.
1405          */
1406         memcpy(buf, bin_attr->private + pos, count);
1407         return count;
1408 }
1409 
1410 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1411                              unsigned int i)
1412 {
1413         if (notes_attrs->dir) {
1414                 while (i-- > 0)
1415                         sysfs_remove_bin_file(notes_attrs->dir,
1416                                               &notes_attrs->attrs[i]);
1417                 kobject_put(notes_attrs->dir);
1418         }
1419         kfree(notes_attrs);
1420 }
1421 
1422 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1423 {
1424         unsigned int notes, loaded, i;
1425         struct module_notes_attrs *notes_attrs;
1426         struct bin_attribute *nattr;
1427 
1428         /* failed to create section attributes, so can't create notes */
1429         if (!mod->sect_attrs)
1430                 return;
1431 
1432         /* Count notes sections and allocate structures.  */
1433         notes = 0;
1434         for (i = 0; i < info->hdr->e_shnum; i++)
1435                 if (!sect_empty(&info->sechdrs[i]) &&
1436                     (info->sechdrs[i].sh_type == SHT_NOTE))
1437                         ++notes;
1438 
1439         if (notes == 0)
1440                 return;
1441 
1442         notes_attrs = kzalloc(sizeof(*notes_attrs)
1443                               + notes * sizeof(notes_attrs->attrs[0]),
1444                               GFP_KERNEL);
1445         if (notes_attrs == NULL)
1446                 return;
1447 
1448         notes_attrs->notes = notes;
1449         nattr = &notes_attrs->attrs[0];
1450         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1451                 if (sect_empty(&info->sechdrs[i]))
1452                         continue;
1453                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1454                         sysfs_bin_attr_init(nattr);
1455                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1456                         nattr->attr.mode = S_IRUGO;
1457                         nattr->size = info->sechdrs[i].sh_size;
1458                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1459                         nattr->read = module_notes_read;
1460                         ++nattr;
1461                 }
1462                 ++loaded;
1463         }
1464 
1465         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1466         if (!notes_attrs->dir)
1467                 goto out;
1468 
1469         for (i = 0; i < notes; ++i)
1470                 if (sysfs_create_bin_file(notes_attrs->dir,
1471                                           &notes_attrs->attrs[i]))
1472                         goto out;
1473 
1474         mod->notes_attrs = notes_attrs;
1475         return;
1476 
1477   out:
1478         free_notes_attrs(notes_attrs, i);
1479 }
1480 
1481 static void remove_notes_attrs(struct module *mod)
1482 {
1483         if (mod->notes_attrs)
1484                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1485 }
1486 
1487 #else
1488 
1489 static inline void add_sect_attrs(struct module *mod,
1490                                   const struct load_info *info)
1491 {
1492 }
1493 
1494 static inline void remove_sect_attrs(struct module *mod)
1495 {
1496 }
1497 
1498 static inline void add_notes_attrs(struct module *mod,
1499                                    const struct load_info *info)
1500 {
1501 }
1502 
1503 static inline void remove_notes_attrs(struct module *mod)
1504 {
1505 }
1506 #endif /* CONFIG_KALLSYMS */
1507 
1508 static void add_usage_links(struct module *mod)
1509 {
1510 #ifdef CONFIG_MODULE_UNLOAD
1511         struct module_use *use;
1512         int nowarn;
1513 
1514         mutex_lock(&module_mutex);
1515         list_for_each_entry(use, &mod->target_list, target_list) {
1516                 nowarn = sysfs_create_link(use->target->holders_dir,
1517                                            &mod->mkobj.kobj, mod->name);
1518         }
1519         mutex_unlock(&module_mutex);
1520 #endif
1521 }
1522 
1523 static void del_usage_links(struct module *mod)
1524 {
1525 #ifdef CONFIG_MODULE_UNLOAD
1526         struct module_use *use;
1527 
1528         mutex_lock(&module_mutex);
1529         list_for_each_entry(use, &mod->target_list, target_list)
1530                 sysfs_remove_link(use->target->holders_dir, mod->name);
1531         mutex_unlock(&module_mutex);
1532 #endif
1533 }
1534 
1535 static int module_add_modinfo_attrs(struct module *mod)
1536 {
1537         struct module_attribute *attr;
1538         struct module_attribute *temp_attr;
1539         int error = 0;
1540         int i;
1541 
1542         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1543                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1544                                         GFP_KERNEL);
1545         if (!mod->modinfo_attrs)
1546                 return -ENOMEM;
1547 
1548         temp_attr = mod->modinfo_attrs;
1549         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1550                 if (!attr->test ||
1551                     (attr->test && attr->test(mod))) {
1552                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1553                         sysfs_attr_init(&temp_attr->attr);
1554                         error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1555                         ++temp_attr;
1556                 }
1557         }
1558         return error;
1559 }
1560 
1561 static void module_remove_modinfo_attrs(struct module *mod)
1562 {
1563         struct module_attribute *attr;
1564         int i;
1565 
1566         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1567                 /* pick a field to test for end of list */
1568                 if (!attr->attr.name)
1569                         break;
1570                 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1571                 if (attr->free)
1572                         attr->free(mod);
1573         }
1574         kfree(mod->modinfo_attrs);
1575 }
1576 
1577 static void mod_kobject_put(struct module *mod)
1578 {
1579         DECLARE_COMPLETION_ONSTACK(c);
1580         mod->mkobj.kobj_completion = &c;
1581         kobject_put(&mod->mkobj.kobj);
1582         wait_for_completion(&c);
1583 }
1584 
1585 static int mod_sysfs_init(struct module *mod)
1586 {
1587         int err;
1588         struct kobject *kobj;
1589 
1590         if (!module_sysfs_initialized) {
1591                 pr_err("%s: module sysfs not initialized\n", mod->name);
1592                 err = -EINVAL;
1593                 goto out;
1594         }
1595 
1596         kobj = kset_find_obj(module_kset, mod->name);
1597         if (kobj) {
1598                 pr_err("%s: module is already loaded\n", mod->name);
1599                 kobject_put(kobj);
1600                 err = -EINVAL;
1601                 goto out;
1602         }
1603 
1604         mod->mkobj.mod = mod;
1605 
1606         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1607         mod->mkobj.kobj.kset = module_kset;
1608         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1609                                    "%s", mod->name);
1610         if (err)
1611                 mod_kobject_put(mod);
1612 
1613         /* delay uevent until full sysfs population */
1614 out:
1615         return err;
1616 }
1617 
1618 static int mod_sysfs_setup(struct module *mod,
1619                            const struct load_info *info,
1620                            struct kernel_param *kparam,
1621                            unsigned int num_params)
1622 {
1623         int err;
1624 
1625         err = mod_sysfs_init(mod);
1626         if (err)
1627                 goto out;
1628 
1629         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1630         if (!mod->holders_dir) {
1631                 err = -ENOMEM;
1632                 goto out_unreg;
1633         }
1634 
1635         err = module_param_sysfs_setup(mod, kparam, num_params);
1636         if (err)
1637                 goto out_unreg_holders;
1638 
1639         err = module_add_modinfo_attrs(mod);
1640         if (err)
1641                 goto out_unreg_param;
1642 
1643         add_usage_links(mod);
1644         add_sect_attrs(mod, info);
1645         add_notes_attrs(mod, info);
1646 
1647         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1648         return 0;
1649 
1650 out_unreg_param:
1651         module_param_sysfs_remove(mod);
1652 out_unreg_holders:
1653         kobject_put(mod->holders_dir);
1654 out_unreg:
1655         mod_kobject_put(mod);
1656 out:
1657         return err;
1658 }
1659 
1660 static void mod_sysfs_fini(struct module *mod)
1661 {
1662         remove_notes_attrs(mod);
1663         remove_sect_attrs(mod);
1664         mod_kobject_put(mod);
1665 }
1666 
1667 #else /* !CONFIG_SYSFS */
1668 
1669 static int mod_sysfs_setup(struct module *mod,
1670                            const struct load_info *info,
1671                            struct kernel_param *kparam,
1672                            unsigned int num_params)
1673 {
1674         return 0;
1675 }
1676 
1677 static void mod_sysfs_fini(struct module *mod)
1678 {
1679 }
1680 
1681 static void module_remove_modinfo_attrs(struct module *mod)
1682 {
1683 }
1684 
1685 static void del_usage_links(struct module *mod)
1686 {
1687 }
1688 
1689 #endif /* CONFIG_SYSFS */
1690 
1691 static void mod_sysfs_teardown(struct module *mod)
1692 {
1693         del_usage_links(mod);
1694         module_remove_modinfo_attrs(mod);
1695         module_param_sysfs_remove(mod);
1696         kobject_put(mod->mkobj.drivers_dir);
1697         kobject_put(mod->holders_dir);
1698         mod_sysfs_fini(mod);
1699 }
1700 
1701 /*
1702  * unlink the module with the whole machine is stopped with interrupts off
1703  * - this defends against kallsyms not taking locks
1704  */
1705 static int __unlink_module(void *_mod)
1706 {
1707         struct module *mod = _mod;
1708         list_del(&mod->list);
1709         module_bug_cleanup(mod);
1710         return 0;
1711 }
1712 
1713 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1714 /*
1715  * LKM RO/NX protection: protect module's text/ro-data
1716  * from modification and any data from execution.
1717  */
1718 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1719 {
1720         unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1721         unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1722 
1723         if (end_pfn > begin_pfn)
1724                 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1725 }
1726 
1727 static void set_section_ro_nx(void *base,
1728                         unsigned long text_size,
1729                         unsigned long ro_size,
1730                         unsigned long total_size)
1731 {
1732         /* begin and end PFNs of the current subsection */
1733         unsigned long begin_pfn;
1734         unsigned long end_pfn;
1735 
1736         /*
1737          * Set RO for module text and RO-data:
1738          * - Always protect first page.
1739          * - Do not protect last partial page.
1740          */
1741         if (ro_size > 0)
1742                 set_page_attributes(base, base + ro_size, set_memory_ro);
1743 
1744         /*
1745          * Set NX permissions for module data:
1746          * - Do not protect first partial page.
1747          * - Always protect last page.
1748          */
1749         if (total_size > text_size) {
1750                 begin_pfn = PFN_UP((unsigned long)base + text_size);
1751                 end_pfn = PFN_UP((unsigned long)base + total_size);
1752                 if (end_pfn > begin_pfn)
1753                         set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1754         }
1755 }
1756 
1757 static void unset_module_core_ro_nx(struct module *mod)
1758 {
1759         set_page_attributes(mod->module_core + mod->core_text_size,
1760                 mod->module_core + mod->core_size,
1761                 set_memory_x);
1762         set_page_attributes(mod->module_core,
1763                 mod->module_core + mod->core_ro_size,
1764                 set_memory_rw);
1765 }
1766 
1767 static void unset_module_init_ro_nx(struct module *mod)
1768 {
1769         set_page_attributes(mod->module_init + mod->init_text_size,
1770                 mod->module_init + mod->init_size,
1771                 set_memory_x);
1772         set_page_attributes(mod->module_init,
1773                 mod->module_init + mod->init_ro_size,
1774                 set_memory_rw);
1775 }
1776 
1777 /* Iterate through all modules and set each module's text as RW */
1778 void set_all_modules_text_rw(void)
1779 {
1780         struct module *mod;
1781 
1782         mutex_lock(&module_mutex);
1783         list_for_each_entry_rcu(mod, &modules, list) {
1784                 if (mod->state == MODULE_STATE_UNFORMED)
1785                         continue;
1786                 if ((mod->module_core) && (mod->core_text_size)) {
1787                         set_page_attributes(mod->module_core,
1788                                                 mod->module_core + mod->core_text_size,
1789                                                 set_memory_rw);
1790                 }
1791                 if ((mod->module_init) && (mod->init_text_size)) {
1792                         set_page_attributes(mod->module_init,
1793                                                 mod->module_init + mod->init_text_size,
1794                                                 set_memory_rw);
1795                 }
1796         }
1797         mutex_unlock(&module_mutex);
1798 }
1799 
1800 /* Iterate through all modules and set each module's text as RO */
1801 void set_all_modules_text_ro(void)
1802 {
1803         struct module *mod;
1804 
1805         mutex_lock(&module_mutex);
1806         list_for_each_entry_rcu(mod, &modules, list) {
1807                 if (mod->state == MODULE_STATE_UNFORMED)
1808                         continue;
1809                 if ((mod->module_core) && (mod->core_text_size)) {
1810                         set_page_attributes(mod->module_core,
1811                                                 mod->module_core + mod->core_text_size,
1812                                                 set_memory_ro);
1813                 }
1814                 if ((mod->module_init) && (mod->init_text_size)) {
1815                         set_page_attributes(mod->module_init,
1816                                                 mod->module_init + mod->init_text_size,
1817                                                 set_memory_ro);
1818                 }
1819         }
1820         mutex_unlock(&module_mutex);
1821 }
1822 #else
1823 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1824 static void unset_module_core_ro_nx(struct module *mod) { }
1825 static void unset_module_init_ro_nx(struct module *mod) { }
1826 #endif
1827 
1828 void __weak module_free(struct module *mod, void *module_region)
1829 {
1830         vfree(module_region);
1831 }
1832 
1833 void __weak module_arch_cleanup(struct module *mod)
1834 {
1835 }
1836 
1837 /* Free a module, remove from lists, etc. */
1838 static void free_module(struct module *mod)
1839 {
1840         trace_module_free(mod);
1841 
1842         mod_sysfs_teardown(mod);
1843 
1844         /* We leave it in list to prevent duplicate loads, but make sure
1845          * that noone uses it while it's being deconstructed. */
1846         mod->state = MODULE_STATE_UNFORMED;
1847 
1848         /* Remove dynamic debug info */
1849         ddebug_remove_module(mod->name);
1850 
1851         /* Arch-specific cleanup. */
1852         module_arch_cleanup(mod);
1853 
1854         /* Module unload stuff */
1855         module_unload_free(mod);
1856 
1857         /* Free any allocated parameters. */
1858         destroy_params(mod->kp, mod->num_kp);
1859 
1860         /* Now we can delete it from the lists */
1861         mutex_lock(&module_mutex);
1862         stop_machine(__unlink_module, mod, NULL);
1863         mutex_unlock(&module_mutex);
1864 
1865         /* This may be NULL, but that's OK */
1866         unset_module_init_ro_nx(mod);
1867         module_free(mod, mod->module_init);
1868         kfree(mod->args);
1869         percpu_modfree(mod);
1870 
1871         /* Free lock-classes: */
1872         lockdep_free_key_range(mod->module_core, mod->core_size);
1873 
1874         /* Finally, free the core (containing the module structure) */
1875         unset_module_core_ro_nx(mod);
1876         module_free(mod, mod->module_core);
1877 
1878 #ifdef CONFIG_MPU
1879         update_protections(current->mm);
1880 #endif
1881 }
1882 
1883 void *__symbol_get(const char *symbol)
1884 {
1885         struct module *owner;
1886         const struct kernel_symbol *sym;
1887 
1888         preempt_disable();
1889         sym = find_symbol(symbol, &owner, NULL, true, true);
1890         if (sym && strong_try_module_get(owner))
1891                 sym = NULL;
1892         preempt_enable();
1893 
1894         return sym ? (void *)sym->value : NULL;
1895 }
1896 EXPORT_SYMBOL_GPL(__symbol_get);
1897 
1898 /*
1899  * Ensure that an exported symbol [global namespace] does not already exist
1900  * in the kernel or in some other module's exported symbol table.
1901  *
1902  * You must hold the module_mutex.
1903  */
1904 static int verify_export_symbols(struct module *mod)
1905 {
1906         unsigned int i;
1907         struct module *owner;
1908         const struct kernel_symbol *s;
1909         struct {
1910                 const struct kernel_symbol *sym;
1911                 unsigned int num;
1912         } arr[] = {
1913                 { mod->syms, mod->num_syms },
1914                 { mod->gpl_syms, mod->num_gpl_syms },
1915                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1916 #ifdef CONFIG_UNUSED_SYMBOLS
1917                 { mod->unused_syms, mod->num_unused_syms },
1918                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1919 #endif
1920         };
1921 
1922         for (i = 0; i < ARRAY_SIZE(arr); i++) {
1923                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1924                         if (find_symbol(s->name, &owner, NULL, true, false)) {
1925                                 pr_err("%s: exports duplicate symbol %s"
1926                                        " (owned by %s)\n",
1927                                        mod->name, s->name, module_name(owner));
1928                                 return -ENOEXEC;
1929                         }
1930                 }
1931         }
1932         return 0;
1933 }
1934 
1935 /* Change all symbols so that st_value encodes the pointer directly. */
1936 static int simplify_symbols(struct module *mod, const struct load_info *info)
1937 {
1938         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1939         Elf_Sym *sym = (void *)symsec->sh_addr;
1940         unsigned long secbase;
1941         unsigned int i;
1942         int ret = 0;
1943         const struct kernel_symbol *ksym;
1944 
1945         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1946                 const char *name = info->strtab + sym[i].st_name;
1947 
1948                 switch (sym[i].st_shndx) {
1949                 case SHN_COMMON:
1950                         /* Ignore common symbols */
1951                         if (!strncmp(name, "__gnu_lto", 9))
1952                                 break;
1953 
1954                         /* We compiled with -fno-common.  These are not
1955                            supposed to happen.  */
1956                         pr_debug("Common symbol: %s\n", name);
1957                         printk("%s: please compile with -fno-common\n",
1958                                mod->name);
1959                         ret = -ENOEXEC;
1960                         break;
1961 
1962                 case SHN_ABS:
1963                         /* Don't need to do anything */
1964                         pr_debug("Absolute symbol: 0x%08lx\n",
1965                                (long)sym[i].st_value);
1966                         break;
1967 
1968                 case SHN_UNDEF:
1969                         ksym = resolve_symbol_wait(mod, info, name);
1970                         /* Ok if resolved.  */
1971                         if (ksym && !IS_ERR(ksym)) {
1972                                 sym[i].st_value = ksym->value;
1973                                 break;
1974                         }
1975 
1976                         /* Ok if weak.  */
1977                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1978                                 break;
1979 
1980                         pr_warn("%s: Unknown symbol %s (err %li)\n",
1981                                 mod->name, name, PTR_ERR(ksym));
1982                         ret = PTR_ERR(ksym) ?: -ENOENT;
1983                         break;
1984 
1985                 default:
1986                         /* Divert to percpu allocation if a percpu var. */
1987                         if (sym[i].st_shndx == info->index.pcpu)
1988                                 secbase = (unsigned long)mod_percpu(mod);
1989                         else
1990                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1991                         sym[i].st_value += secbase;
1992                         break;
1993                 }
1994         }
1995 
1996         return ret;
1997 }
1998 
1999 static int apply_relocations(struct module *mod, const struct load_info *info)
2000 {
2001         unsigned int i;
2002         int err = 0;
2003 
2004         /* Now do relocations. */
2005         for (i = 1; i < info->hdr->e_shnum; i++) {
2006                 unsigned int infosec = info->sechdrs[i].sh_info;
2007 
2008                 /* Not a valid relocation section? */
2009                 if (infosec >= info->hdr->e_shnum)
2010                         continue;
2011 
2012                 /* Don't bother with non-allocated sections */
2013                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2014                         continue;
2015 
2016                 if (info->sechdrs[i].sh_type == SHT_REL)
2017                         err = apply_relocate(info->sechdrs, info->strtab,
2018                                              info->index.sym, i, mod);
2019                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2020                         err = apply_relocate_add(info->sechdrs, info->strtab,
2021                                                  info->index.sym, i, mod);
2022                 if (err < 0)
2023                         break;
2024         }
2025         return err;
2026 }
2027 
2028 /* Additional bytes needed by arch in front of individual sections */
2029 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2030                                              unsigned int section)
2031 {
2032         /* default implementation just returns zero */
2033         return 0;
2034 }
2035 
2036 /* Update size with this section: return offset. */
2037 static long get_offset(struct module *mod, unsigned int *size,
2038                        Elf_Shdr *sechdr, unsigned int section)
2039 {
2040         long ret;
2041 
2042         *size += arch_mod_section_prepend(mod, section);
2043         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2044         *size = ret + sechdr->sh_size;
2045         return ret;
2046 }
2047 
2048 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2049    might -- code, read-only data, read-write data, small data.  Tally
2050    sizes, and place the offsets into sh_entsize fields: high bit means it
2051    belongs in init. */
2052 static void layout_sections(struct module *mod, struct load_info *info)
2053 {
2054         static unsigned long const masks[][2] = {
2055                 /* NOTE: all executable code must be the first section
2056                  * in this array; otherwise modify the text_size
2057                  * finder in the two loops below */
2058                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2059                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2060                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2061                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2062         };
2063         unsigned int m, i;
2064 
2065         for (i = 0; i < info->hdr->e_shnum; i++)
2066                 info->sechdrs[i].sh_entsize = ~0UL;
2067 
2068         pr_debug("Core section allocation order:\n");
2069         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2070                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2071                         Elf_Shdr *s = &info->sechdrs[i];
2072                         const char *sname = info->secstrings + s->sh_name;
2073 
2074                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2075                             || (s->sh_flags & masks[m][1])
2076                             || s->sh_entsize != ~0UL
2077                             || strstarts(sname, ".init"))
2078                                 continue;
2079                         s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2080                         pr_debug("\t%s\n", sname);
2081                 }
2082                 switch (m) {
2083                 case 0: /* executable */
2084                         mod->core_size = debug_align(mod->core_size);
2085                         mod->core_text_size = mod->core_size;
2086                         break;
2087                 case 1: /* RO: text and ro-data */
2088                         mod->core_size = debug_align(mod->core_size);
2089                         mod->core_ro_size = mod->core_size;
2090                         break;
2091                 case 3: /* whole core */
2092                         mod->core_size = debug_align(mod->core_size);
2093                         break;
2094                 }
2095         }
2096 
2097         pr_debug("Init section allocation order:\n");
2098         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2099                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2100                         Elf_Shdr *s = &info->sechdrs[i];
2101                         const char *sname = info->secstrings + s->sh_name;
2102 
2103                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2104                             || (s->sh_flags & masks[m][1])
2105                             || s->sh_entsize != ~0UL
2106                             || !strstarts(sname, ".init"))
2107                                 continue;
2108                         s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2109                                          | INIT_OFFSET_MASK);
2110                         pr_debug("\t%s\n", sname);
2111                 }
2112                 switch (m) {
2113                 case 0: /* executable */
2114                         mod->init_size = debug_align(mod->init_size);
2115                         mod->init_text_size = mod->init_size;
2116                         break;
2117                 case 1: /* RO: text and ro-data */
2118                         mod->init_size = debug_align(mod->init_size);
2119                         mod->init_ro_size = mod->init_size;
2120                         break;
2121                 case 3: /* whole init */
2122                         mod->init_size = debug_align(mod->init_size);
2123                         break;
2124                 }
2125         }
2126 }
2127 
2128 static void set_license(struct module *mod, const char *license)
2129 {
2130         if (!license)
2131                 license = "unspecified";
2132 
2133         if (!license_is_gpl_compatible(license)) {
2134                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2135                         pr_warn("%s: module license '%s' taints kernel.\n",
2136                                 mod->name, license);
2137                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2138                                  LOCKDEP_NOW_UNRELIABLE);
2139         }
2140 }
2141 
2142 /* Parse tag=value strings from .modinfo section */
2143 static char *next_string(char *string, unsigned long *secsize)
2144 {
2145         /* Skip non-zero chars */
2146         while (string[0]) {
2147                 string++;
2148                 if ((*secsize)-- <= 1)
2149                         return NULL;
2150         }
2151 
2152         /* Skip any zero padding. */
2153         while (!string[0]) {
2154                 string++;
2155                 if ((*secsize)-- <= 1)
2156                         return NULL;
2157         }
2158         return string;
2159 }
2160 
2161 static char *get_modinfo(struct load_info *info, const char *tag)
2162 {
2163         char *p;
2164         unsigned int taglen = strlen(tag);
2165         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2166         unsigned long size = infosec->sh_size;
2167 
2168         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2169                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2170                         return p + taglen + 1;
2171         }
2172         return NULL;
2173 }
2174 
2175 static void setup_modinfo(struct module *mod, struct load_info *info)
2176 {
2177         struct module_attribute *attr;
2178         int i;
2179 
2180         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2181                 if (attr->setup)
2182                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2183         }
2184 }
2185 
2186 static void free_modinfo(struct module *mod)
2187 {
2188         struct module_attribute *attr;
2189         int i;
2190 
2191         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2192                 if (attr->free)
2193                         attr->free(mod);
2194         }
2195 }
2196 
2197 #ifdef CONFIG_KALLSYMS
2198 
2199 /* lookup symbol in given range of kernel_symbols */
2200 static const struct kernel_symbol *lookup_symbol(const char *name,
2201         const struct kernel_symbol *start,
2202         const struct kernel_symbol *stop)
2203 {
2204         return bsearch(name, start, stop - start,
2205                         sizeof(struct kernel_symbol), cmp_name);
2206 }
2207 
2208 static int is_exported(const char *name, unsigned long value,
2209                        const struct module *mod)
2210 {
2211         const struct kernel_symbol *ks;
2212         if (!mod)
2213                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2214         else
2215                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2216         return ks != NULL && ks->value == value;
2217 }
2218 
2219 /* As per nm */
2220 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2221 {
2222         const Elf_Shdr *sechdrs = info->sechdrs;
2223 
2224         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2225                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2226                         return 'v';
2227                 else
2228                         return 'w';
2229         }
2230         if (sym->st_shndx == SHN_UNDEF)
2231                 return 'U';
2232         if (sym->st_shndx == SHN_ABS)
2233                 return 'a';
2234         if (sym->st_shndx >= SHN_LORESERVE)
2235                 return '?';
2236         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2237                 return 't';
2238         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2239             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2240                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2241                         return 'r';
2242                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2243                         return 'g';
2244                 else
2245                         return 'd';
2246         }
2247         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2248                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2249                         return 's';
2250                 else
2251                         return 'b';
2252         }
2253         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2254                       ".debug")) {
2255                 return 'n';
2256         }
2257         return '?';
2258 }
2259 
2260 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2261                            unsigned int shnum)
2262 {
2263         const Elf_Shdr *sec;
2264 
2265         if (src->st_shndx == SHN_UNDEF
2266             || src->st_shndx >= shnum
2267             || !src->st_name)
2268                 return false;
2269 
2270         sec = sechdrs + src->st_shndx;
2271         if (!(sec->sh_flags & SHF_ALLOC)
2272 #ifndef CONFIG_KALLSYMS_ALL
2273             || !(sec->sh_flags & SHF_EXECINSTR)
2274 #endif
2275             || (sec->sh_entsize & INIT_OFFSET_MASK))
2276                 return false;
2277 
2278         return true;
2279 }
2280 
2281 /*
2282  * We only allocate and copy the strings needed by the parts of symtab
2283  * we keep.  This is simple, but has the effect of making multiple
2284  * copies of duplicates.  We could be more sophisticated, see
2285  * linux-kernel thread starting with
2286  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2287  */
2288 static void layout_symtab(struct module *mod, struct load_info *info)
2289 {
2290         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2291         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2292         const Elf_Sym *src;
2293         unsigned int i, nsrc, ndst, strtab_size = 0;
2294 
2295         /* Put symbol section at end of init part of module. */
2296         symsect->sh_flags |= SHF_ALLOC;
2297         symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2298                                          info->index.sym) | INIT_OFFSET_MASK;
2299         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2300 
2301         src = (void *)info->hdr + symsect->sh_offset;
2302         nsrc = symsect->sh_size / sizeof(*src);
2303 
2304         /* Compute total space required for the core symbols' strtab. */
2305         for (ndst = i = 0; i < nsrc; i++) {
2306                 if (i == 0 ||
2307                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2308                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2309                         ndst++;
2310                 }
2311         }
2312 
2313         /* Append room for core symbols at end of core part. */
2314         info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2315         info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2316         mod->core_size += strtab_size;
2317 
2318         /* Put string table section at end of init part of module. */
2319         strsect->sh_flags |= SHF_ALLOC;
2320         strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2321                                          info->index.str) | INIT_OFFSET_MASK;
2322         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2323 }
2324 
2325 static void add_kallsyms(struct module *mod, const struct load_info *info)
2326 {
2327         unsigned int i, ndst;
2328         const Elf_Sym *src;
2329         Elf_Sym *dst;
2330         char *s;
2331         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2332 
2333         mod->symtab = (void *)symsec->sh_addr;
2334         mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2335         /* Make sure we get permanent strtab: don't use info->strtab. */
2336         mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2337 
2338         /* Set types up while we still have access to sections. */
2339         for (i = 0; i < mod->num_symtab; i++)
2340                 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2341 
2342         mod->core_symtab = dst = mod->module_core + info->symoffs;
2343         mod->core_strtab = s = mod->module_core + info->stroffs;
2344         src = mod->symtab;
2345         for (ndst = i = 0; i < mod->num_symtab; i++) {
2346                 if (i == 0 ||
2347                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2348                         dst[ndst] = src[i];
2349                         dst[ndst++].st_name = s - mod->core_strtab;
2350                         s += strlcpy(s, &mod->strtab[src[i].st_name],
2351                                      KSYM_NAME_LEN) + 1;
2352                 }
2353         }
2354         mod->core_num_syms = ndst;
2355 }
2356 #else
2357 static inline void layout_symtab(struct module *mod, struct load_info *info)
2358 {
2359 }
2360 
2361 static void add_kallsyms(struct module *mod, const struct load_info *info)
2362 {
2363 }
2364 #endif /* CONFIG_KALLSYMS */
2365 
2366 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2367 {
2368         if (!debug)
2369                 return;
2370 #ifdef CONFIG_DYNAMIC_DEBUG
2371         if (ddebug_add_module(debug, num, debug->modname))
2372                 pr_err("dynamic debug error adding module: %s\n",
2373                         debug->modname);
2374 #endif
2375 }
2376 
2377 static void dynamic_debug_remove(struct _ddebug *debug)
2378 {
2379         if (debug)
2380                 ddebug_remove_module(debug->modname);
2381 }
2382 
2383 void * __weak module_alloc(unsigned long size)
2384 {
2385         return vmalloc_exec(size);
2386 }
2387 
2388 static void *module_alloc_update_bounds(unsigned long size)
2389 {
2390         void *ret = module_alloc(size);
2391 
2392         if (ret) {
2393                 mutex_lock(&module_mutex);
2394                 /* Update module bounds. */
2395                 if ((unsigned long)ret < module_addr_min)
2396                         module_addr_min = (unsigned long)ret;
2397                 if ((unsigned long)ret + size > module_addr_max)
2398                         module_addr_max = (unsigned long)ret + size;
2399                 mutex_unlock(&module_mutex);
2400         }
2401         return ret;
2402 }
2403 
2404 #ifdef CONFIG_DEBUG_KMEMLEAK
2405 static void kmemleak_load_module(const struct module *mod,
2406                                  const struct load_info *info)
2407 {
2408         unsigned int i;
2409 
2410         /* only scan the sections containing data */
2411         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2412 
2413         for (i = 1; i < info->hdr->e_shnum; i++) {
2414                 /* Scan all writable sections that's not executable */
2415                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2416                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2417                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2418                         continue;
2419 
2420                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2421                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2422         }
2423 }
2424 #else
2425 static inline void kmemleak_load_module(const struct module *mod,
2426                                         const struct load_info *info)
2427 {
2428 }
2429 #endif
2430 
2431 #ifdef CONFIG_MODULE_SIG
2432 static int module_sig_check(struct load_info *info)
2433 {
2434         int err = -ENOKEY;
2435         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2436         const void *mod = info->hdr;
2437 
2438         if (info->len > markerlen &&
2439             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2440                 /* We truncate the module to discard the signature */
2441                 info->len -= markerlen;
2442                 err = mod_verify_sig(mod, &info->len);
2443         }
2444 
2445         if (!err) {
2446                 info->sig_ok = true;
2447                 return 0;
2448         }
2449 
2450         /* Not having a signature is only an error if we're strict. */
2451         if (err < 0 && fips_enabled)
2452                 panic("Module verification failed with error %d in FIPS mode\n",
2453                       err);
2454         if (err == -ENOKEY && !sig_enforce)
2455                 err = 0;
2456 
2457         return err;
2458 }
2459 #else /* !CONFIG_MODULE_SIG */
2460 static int module_sig_check(struct load_info *info)
2461 {
2462         return 0;
2463 }
2464 #endif /* !CONFIG_MODULE_SIG */
2465 
2466 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2467 static int elf_header_check(struct load_info *info)
2468 {
2469         if (info->len < sizeof(*(info->hdr)))
2470                 return -ENOEXEC;
2471 
2472         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2473             || info->hdr->e_type != ET_REL
2474             || !elf_check_arch(info->hdr)
2475             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2476                 return -ENOEXEC;
2477 
2478         if (info->hdr->e_shoff >= info->len
2479             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2480                 info->len - info->hdr->e_shoff))
2481                 return -ENOEXEC;
2482 
2483         return 0;
2484 }
2485 
2486 /* Sets info->hdr and info->len. */
2487 static int copy_module_from_user(const void __user *umod, unsigned long len,
2488                                   struct load_info *info)
2489 {
2490         int err;
2491 
2492         info->len = len;
2493         if (info->len < sizeof(*(info->hdr)))
2494                 return -ENOEXEC;
2495 
2496         err = security_kernel_module_from_file(NULL);
2497         if (err)
2498                 return err;
2499 
2500         /* Suck in entire file: we'll want most of it. */
2501         info->hdr = vmalloc(info->len);
2502         if (!info->hdr)
2503                 return -ENOMEM;
2504 
2505         if (copy_from_user(info->hdr, umod, info->len) != 0) {
2506                 vfree(info->hdr);
2507                 return -EFAULT;
2508         }
2509 
2510         return 0;
2511 }
2512 
2513 /* Sets info->hdr and info->len. */
2514 static int copy_module_from_fd(int fd, struct load_info *info)
2515 {
2516         struct fd f = fdget(fd);
2517         int err;
2518         struct kstat stat;
2519         loff_t pos;
2520         ssize_t bytes = 0;
2521 
2522         if (!f.file)
2523                 return -ENOEXEC;
2524 
2525         err = security_kernel_module_from_file(f.file);
2526         if (err)
2527                 goto out;
2528 
2529         err = vfs_getattr(&f.file->f_path, &stat);
2530         if (err)
2531                 goto out;
2532 
2533         if (stat.size > INT_MAX) {
2534                 err = -EFBIG;
2535                 goto out;
2536         }
2537 
2538         /* Don't hand 0 to vmalloc, it whines. */
2539         if (stat.size == 0) {
2540                 err = -EINVAL;
2541                 goto out;
2542         }
2543 
2544         info->hdr = vmalloc(stat.size);
2545         if (!info->hdr) {
2546                 err = -ENOMEM;
2547                 goto out;
2548         }
2549 
2550         pos = 0;
2551         while (pos < stat.size) {
2552                 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2553                                     stat.size - pos);
2554                 if (bytes < 0) {
2555                         vfree(info->hdr);
2556                         err = bytes;
2557                         goto out;
2558                 }
2559                 if (bytes == 0)
2560                         break;
2561                 pos += bytes;
2562         }
2563         info->len = pos;
2564 
2565 out:
2566         fdput(f);
2567         return err;
2568 }
2569 
2570 static void free_copy(struct load_info *info)
2571 {
2572         vfree(info->hdr);
2573 }
2574 
2575 static int rewrite_section_headers(struct load_info *info, int flags)
2576 {
2577         unsigned int i;
2578 
2579         /* This should always be true, but let's be sure. */
2580         info->sechdrs[0].sh_addr = 0;
2581 
2582         for (i = 1; i < info->hdr->e_shnum; i++) {
2583                 Elf_Shdr *shdr = &info->sechdrs[i];
2584                 if (shdr->sh_type != SHT_NOBITS
2585                     && info->len < shdr->sh_offset + shdr->sh_size) {
2586                         pr_err("Module len %lu truncated\n", info->len);
2587                         return -ENOEXEC;
2588                 }
2589 
2590                 /* Mark all sections sh_addr with their address in the
2591                    temporary image. */
2592                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2593 
2594 #ifndef CONFIG_MODULE_UNLOAD
2595                 /* Don't load .exit sections */
2596                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2597                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2598 #endif
2599         }
2600 
2601         /* Track but don't keep modinfo and version sections. */
2602         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2603                 info->index.vers = 0; /* Pretend no __versions section! */
2604         else
2605                 info->index.vers = find_sec(info, "__versions");
2606         info->index.info = find_sec(info, ".modinfo");
2607         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2608         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2609         return 0;
2610 }
2611 
2612 /*
2613  * Set up our basic convenience variables (pointers to section headers,
2614  * search for module section index etc), and do some basic section
2615  * verification.
2616  *
2617  * Return the temporary module pointer (we'll replace it with the final
2618  * one when we move the module sections around).
2619  */
2620 static struct module *setup_load_info(struct load_info *info, int flags)
2621 {
2622         unsigned int i;
2623         int err;
2624         struct module *mod;
2625 
2626         /* Set up the convenience variables */
2627         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2628         info->secstrings = (void *)info->hdr
2629                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2630 
2631         err = rewrite_section_headers(info, flags);
2632         if (err)
2633                 return ERR_PTR(err);
2634 
2635         /* Find internal symbols and strings. */
2636         for (i = 1; i < info->hdr->e_shnum; i++) {
2637                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2638                         info->index.sym = i;
2639                         info->index.str = info->sechdrs[i].sh_link;
2640                         info->strtab = (char *)info->hdr
2641                                 + info->sechdrs[info->index.str].sh_offset;
2642                         break;
2643                 }
2644         }
2645 
2646         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2647         if (!info->index.mod) {
2648                 pr_warn("No module found in object\n");
2649                 return ERR_PTR(-ENOEXEC);
2650         }
2651         /* This is temporary: point mod into copy of data. */
2652         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2653 
2654         if (info->index.sym == 0) {
2655                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2656                 return ERR_PTR(-ENOEXEC);
2657         }
2658 
2659         info->index.pcpu = find_pcpusec(info);
2660 
2661         /* Check module struct version now, before we try to use module. */
2662         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2663                 return ERR_PTR(-ENOEXEC);
2664 
2665         return mod;
2666 }
2667 
2668 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2669 {
2670         const char *modmagic = get_modinfo(info, "vermagic");
2671         int err;
2672 
2673         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2674                 modmagic = NULL;
2675 
2676         /* This is allowed: modprobe --force will invalidate it. */
2677         if (!modmagic) {
2678                 err = try_to_force_load(mod, "bad vermagic");
2679                 if (err)
2680                         return err;
2681         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2682                 pr_err("%s: version magic '%s' should be '%s'\n",
2683                        mod->name, modmagic, vermagic);
2684                 return -ENOEXEC;
2685         }
2686 
2687         if (!get_modinfo(info, "intree"))
2688                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2689 
2690         if (get_modinfo(info, "staging")) {
2691                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2692                 pr_warn("%s: module is from the staging directory, the quality "
2693                         "is unknown, you have been warned.\n", mod->name);
2694         }
2695 
2696         /* Set up license info based on the info section */
2697         set_license(mod, get_modinfo(info, "license"));
2698 
2699         return 0;
2700 }
2701 
2702 static int find_module_sections(struct module *mod, struct load_info *info)
2703 {
2704         mod->kp = section_objs(info, "__param",
2705                                sizeof(*mod->kp), &mod->num_kp);
2706         mod->syms = section_objs(info, "__ksymtab",
2707                                  sizeof(*mod->syms), &mod->num_syms);
2708         mod->crcs = section_addr(info, "__kcrctab");
2709         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2710                                      sizeof(*mod->gpl_syms),
2711                                      &mod->num_gpl_syms);
2712         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2713         mod->gpl_future_syms = section_objs(info,
2714                                             "__ksymtab_gpl_future",
2715                                             sizeof(*mod->gpl_future_syms),
2716                                             &mod->num_gpl_future_syms);
2717         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2718 
2719 #ifdef CONFIG_UNUSED_SYMBOLS
2720         mod->unused_syms = section_objs(info, "__ksymtab_unused",
2721                                         sizeof(*mod->unused_syms),
2722                                         &mod->num_unused_syms);
2723         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2724         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2725                                             sizeof(*mod->unused_gpl_syms),
2726                                             &mod->num_unused_gpl_syms);
2727         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2728 #endif
2729 #ifdef CONFIG_CONSTRUCTORS
2730         mod->ctors = section_objs(info, ".ctors",
2731                                   sizeof(*mod->ctors), &mod->num_ctors);
2732         if (!mod->ctors)
2733                 mod->ctors = section_objs(info, ".init_array",
2734                                 sizeof(*mod->ctors), &mod->num_ctors);
2735         else if (find_sec(info, ".init_array")) {
2736                 /*
2737                  * This shouldn't happen with same compiler and binutils
2738                  * building all parts of the module.
2739                  */
2740                 printk(KERN_WARNING "%s: has both .ctors and .init_array.\n",
2741                        mod->name);
2742                 return -EINVAL;
2743         }
2744 #endif
2745 
2746 #ifdef CONFIG_TRACEPOINTS
2747         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2748                                              sizeof(*mod->tracepoints_ptrs),
2749                                              &mod->num_tracepoints);
2750 #endif
2751 #ifdef HAVE_JUMP_LABEL
2752         mod->jump_entries = section_objs(info, "__jump_table",
2753                                         sizeof(*mod->jump_entries),
2754                                         &mod->num_jump_entries);
2755 #endif
2756 #ifdef CONFIG_EVENT_TRACING
2757         mod->trace_events = section_objs(info, "_ftrace_events",
2758                                          sizeof(*mod->trace_events),
2759                                          &mod->num_trace_events);
2760 #endif
2761 #ifdef CONFIG_TRACING
2762         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2763                                          sizeof(*mod->trace_bprintk_fmt_start),
2764                                          &mod->num_trace_bprintk_fmt);
2765 #endif
2766 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2767         /* sechdrs[0].sh_size is always zero */
2768         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2769                                              sizeof(*mod->ftrace_callsites),
2770                                              &mod->num_ftrace_callsites);
2771 #endif
2772 
2773         mod->extable = section_objs(info, "__ex_table",
2774                                     sizeof(*mod->extable), &mod->num_exentries);
2775 
2776         if (section_addr(info, "__obsparm"))
2777                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2778 
2779         info->debug = section_objs(info, "__verbose",
2780                                    sizeof(*info->debug), &info->num_debug);
2781 
2782         return 0;
2783 }
2784 
2785 static int move_module(struct module *mod, struct load_info *info)
2786 {
2787         int i;
2788         void *ptr;
2789 
2790         /* Do the allocs. */
2791         ptr = module_alloc_update_bounds(mod->core_size);
2792         /*
2793          * The pointer to this block is stored in the module structure
2794          * which is inside the block. Just mark it as not being a
2795          * leak.
2796          */
2797         kmemleak_not_leak(ptr);
2798         if (!ptr)
2799                 return -ENOMEM;
2800 
2801         memset(ptr, 0, mod->core_size);
2802         mod->module_core = ptr;
2803 
2804         if (mod->init_size) {
2805                 ptr = module_alloc_update_bounds(mod->init_size);
2806                 /*
2807                  * The pointer to this block is stored in the module structure
2808                  * which is inside the block. This block doesn't need to be
2809                  * scanned as it contains data and code that will be freed
2810                  * after the module is initialized.
2811                  */
2812                 kmemleak_ignore(ptr);
2813                 if (!ptr) {
2814                         module_free(mod, mod->module_core);
2815                         return -ENOMEM;
2816                 }
2817                 memset(ptr, 0, mod->init_size);
2818                 mod->module_init = ptr;
2819         } else
2820                 mod->module_init = NULL;
2821 
2822         /* Transfer each section which specifies SHF_ALLOC */
2823         pr_debug("final section addresses:\n");
2824         for (i = 0; i < info->hdr->e_shnum; i++) {
2825                 void *dest;
2826                 Elf_Shdr *shdr = &info->sechdrs[i];
2827 
2828                 if (!(shdr->sh_flags & SHF_ALLOC))
2829                         continue;
2830 
2831                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2832                         dest = mod->module_init
2833                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2834                 else
2835                         dest = mod->module_core + shdr->sh_entsize;
2836 
2837                 if (shdr->sh_type != SHT_NOBITS)
2838                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2839                 /* Update sh_addr to point to copy in image. */
2840                 shdr->sh_addr = (unsigned long)dest;
2841                 pr_debug("\t0x%lx %s\n",
2842                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2843         }
2844 
2845         return 0;
2846 }
2847 
2848 static int check_module_license_and_versions(struct module *mod)
2849 {
2850         /*
2851          * ndiswrapper is under GPL by itself, but loads proprietary modules.
2852          * Don't use add_taint_module(), as it would prevent ndiswrapper from
2853          * using GPL-only symbols it needs.
2854          */
2855         if (strcmp(mod->name, "ndiswrapper") == 0)
2856                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2857 
2858         /* driverloader was caught wrongly pretending to be under GPL */
2859         if (strcmp(mod->name, "driverloader") == 0)
2860                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2861                                  LOCKDEP_NOW_UNRELIABLE);
2862 
2863         /* lve claims to be GPL but upstream won't provide source */
2864         if (strcmp(mod->name, "lve") == 0)
2865                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2866                                  LOCKDEP_NOW_UNRELIABLE);
2867 
2868 #ifdef CONFIG_MODVERSIONS
2869         if ((mod->num_syms && !mod->crcs)
2870             || (mod->num_gpl_syms && !mod->gpl_crcs)
2871             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2872 #ifdef CONFIG_UNUSED_SYMBOLS
2873             || (mod->num_unused_syms && !mod->unused_crcs)
2874             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2875 #endif
2876                 ) {
2877                 return try_to_force_load(mod,
2878                                          "no versions for exported symbols");
2879         }
2880 #endif
2881         return 0;
2882 }
2883 
2884 static void flush_module_icache(const struct module *mod)
2885 {
2886         mm_segment_t old_fs;
2887 
2888         /* flush the icache in correct context */
2889         old_fs = get_fs();
2890         set_fs(KERNEL_DS);
2891 
2892         /*
2893          * Flush the instruction cache, since we've played with text.
2894          * Do it before processing of module parameters, so the module
2895          * can provide parameter accessor functions of its own.
2896          */
2897         if (mod->module_init)
2898                 flush_icache_range((unsigned long)mod->module_init,
2899                                    (unsigned long)mod->module_init
2900                                    + mod->init_size);
2901         flush_icache_range((unsigned long)mod->module_core,
2902                            (unsigned long)mod->module_core + mod->core_size);
2903 
2904         set_fs(old_fs);
2905 }
2906 
2907 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2908                                      Elf_Shdr *sechdrs,
2909                                      char *secstrings,
2910                                      struct module *mod)
2911 {
2912         return 0;
2913 }
2914 
2915 static struct module *layout_and_allocate(struct load_info *info, int flags)
2916 {
2917         /* Module within temporary copy. */
2918         struct module *mod;
2919         int err;
2920 
2921         mod = setup_load_info(info, flags);
2922         if (IS_ERR(mod))
2923                 return mod;
2924 
2925         err = check_modinfo(mod, info, flags);
2926         if (err)
2927                 return ERR_PTR(err);
2928 
2929         /* Allow arches to frob section contents and sizes.  */
2930         err = module_frob_arch_sections(info->hdr, info->sechdrs,
2931                                         info->secstrings, mod);
2932         if (err < 0)
2933                 return ERR_PTR(err);
2934 
2935         /* We will do a special allocation for per-cpu sections later. */
2936         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2937 
2938         /* Determine total sizes, and put offsets in sh_entsize.  For now
2939            this is done generically; there doesn't appear to be any
2940            special cases for the architectures. */
2941         layout_sections(mod, info);
2942         layout_symtab(mod, info);
2943 
2944         /* Allocate and move to the final place */
2945         err = move_module(mod, info);
2946         if (err)
2947                 return ERR_PTR(err);
2948 
2949         /* Module has been copied to its final place now: return it. */
2950         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2951         kmemleak_load_module(mod, info);
2952         return mod;
2953 }
2954 
2955 /* mod is no longer valid after this! */
2956 static void module_deallocate(struct module *mod, struct load_info *info)
2957 {
2958         percpu_modfree(mod);
2959         module_free(mod, mod->module_init);
2960         module_free(mod, mod->module_core);
2961 }
2962 
2963 int __weak module_finalize(const Elf_Ehdr *hdr,
2964                            const Elf_Shdr *sechdrs,
2965                            struct module *me)
2966 {
2967         return 0;
2968 }
2969 
2970 static int post_relocation(struct module *mod, const struct load_info *info)
2971 {
2972         /* Sort exception table now relocations are done. */
2973         sort_extable(mod->extable, mod->extable + mod->num_exentries);
2974 
2975         /* Copy relocated percpu area over. */
2976         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2977                        info->sechdrs[info->index.pcpu].sh_size);
2978 
2979         /* Setup kallsyms-specific fields. */
2980         add_kallsyms(mod, info);
2981 
2982         /* Arch-specific module finalizing. */
2983         return module_finalize(info->hdr, info->sechdrs, mod);
2984 }
2985 
2986 /* Is this module of this name done loading?  No locks held. */
2987 static bool finished_loading(const char *name)
2988 {
2989         struct module *mod;
2990         bool ret;
2991 
2992         mutex_lock(&module_mutex);
2993         mod = find_module_all(name, strlen(name), true);
2994         ret = !mod || mod->state == MODULE_STATE_LIVE
2995                 || mod->state == MODULE_STATE_GOING;
2996         mutex_unlock(&module_mutex);
2997 
2998         return ret;
2999 }
3000 
3001 /* Call module constructors. */
3002 static void do_mod_ctors(struct module *mod)
3003 {
3004 #ifdef CONFIG_CONSTRUCTORS
3005         unsigned long i;
3006 
3007         for (i = 0; i < mod->num_ctors; i++)
3008                 mod->ctors[i]();
3009 #endif
3010 }
3011 
3012 /* This is where the real work happens */
3013 static int do_init_module(struct module *mod)
3014 {
3015         int ret = 0;
3016 
3017         /*
3018          * We want to find out whether @mod uses async during init.  Clear
3019          * PF_USED_ASYNC.  async_schedule*() will set it.
3020          */
3021         current->flags &= ~PF_USED_ASYNC;
3022 
3023         do_mod_ctors(mod);
3024         /* Start the module */
3025         if (mod->init != NULL)
3026                 ret = do_one_initcall(mod->init);
3027         if (ret < 0) {
3028                 /* Init routine failed: abort.  Try to protect us from
3029                    buggy refcounters. */
3030                 mod->state = MODULE_STATE_GOING;
3031                 synchronize_sched();
3032                 module_put(mod);
3033                 blocking_notifier_call_chain(&module_notify_list,
3034                                              MODULE_STATE_GOING, mod);
3035                 free_module(mod);
3036                 wake_up_all(&module_wq);
3037                 return ret;
3038         }
3039         if (ret > 0) {
3040                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3041                         "follow 0/-E convention\n"
3042                         "%s: loading module anyway...\n",
3043                         __func__, mod->name, ret, __func__);
3044                 dump_stack();
3045         }
3046 
3047         /* Now it's a first class citizen! */
3048         mod->state = MODULE_STATE_LIVE;
3049         blocking_notifier_call_chain(&module_notify_list,
3050                                      MODULE_STATE_LIVE, mod);
3051 
3052         /*
3053          * We need to finish all async code before the module init sequence
3054          * is done.  This has potential to deadlock.  For example, a newly
3055          * detected block device can trigger request_module() of the
3056          * default iosched from async probing task.  Once userland helper
3057          * reaches here, async_synchronize_full() will wait on the async
3058          * task waiting on request_module() and deadlock.
3059          *
3060          * This deadlock is avoided by perfomring async_synchronize_full()
3061          * iff module init queued any async jobs.  This isn't a full
3062          * solution as it will deadlock the same if module loading from
3063          * async jobs nests more than once; however, due to the various
3064          * constraints, this hack seems to be the best option for now.
3065          * Please refer to the following thread for details.
3066          *
3067          * http://thread.gmane.org/gmane.linux.kernel/1420814
3068          */
3069         if (current->flags & PF_USED_ASYNC)
3070                 async_synchronize_full();
3071 
3072         mutex_lock(&module_mutex);
3073         /* Drop initial reference. */
3074         module_put(mod);
3075         trim_init_extable(mod);
3076 #ifdef CONFIG_KALLSYMS
3077         mod->num_symtab = mod->core_num_syms;
3078         mod->symtab = mod->core_symtab;
3079         mod->strtab = mod->core_strtab;
3080 #endif
3081         unset_module_init_ro_nx(mod);
3082         module_free(mod, mod->module_init);
3083         mod->module_init = NULL;
3084         mod->init_size = 0;
3085         mod->init_ro_size = 0;
3086         mod->init_text_size = 0;
3087         mutex_unlock(&module_mutex);
3088         wake_up_all(&module_wq);
3089 
3090         return 0;
3091 }
3092 
3093 static int may_init_module(void)
3094 {
3095         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3096                 return -EPERM;
3097 
3098         return 0;
3099 }
3100 
3101 /*
3102  * We try to place it in the list now to make sure it's unique before
3103  * we dedicate too many resources.  In particular, temporary percpu
3104  * memory exhaustion.
3105  */
3106 static int add_unformed_module(struct module *mod)
3107 {
3108         int err;
3109         struct module *old;
3110 
3111         mod->state = MODULE_STATE_UNFORMED;
3112 
3113 again:
3114         mutex_lock(&module_mutex);
3115         old = find_module_all(mod->name, strlen(mod->name), true);
3116         if (old != NULL) {
3117                 if (old->state == MODULE_STATE_COMING
3118                     || old->state == MODULE_STATE_UNFORMED) {
3119                         /* Wait in case it fails to load. */
3120                         mutex_unlock(&module_mutex);
3121                         err = wait_event_interruptible(module_wq,
3122                                                finished_loading(mod->name));
3123                         if (err)
3124                                 goto out_unlocked;
3125                         goto again;
3126                 }
3127                 err = -EEXIST;
3128                 goto out;
3129         }
3130         list_add_rcu(&mod->list, &modules);
3131         err = 0;
3132 
3133 out:
3134         mutex_unlock(&module_mutex);
3135 out_unlocked:
3136         return err;
3137 }
3138 
3139 static int complete_formation(struct module *mod, struct load_info *info)
3140 {
3141         int err;
3142 
3143         mutex_lock(&module_mutex);
3144 
3145         /* Find duplicate symbols (must be called under lock). */
3146         err = verify_export_symbols(mod);
3147         if (err < 0)
3148                 goto out;
3149 
3150         /* This relies on module_mutex for list integrity. */
3151         module_bug_finalize(info->hdr, info->sechdrs, mod);
3152 
3153         /* Set RO and NX regions for core */
3154         set_section_ro_nx(mod->module_core,
3155                                 mod->core_text_size,
3156                                 mod->core_ro_size,
3157                                 mod->core_size);
3158 
3159         /* Set RO and NX regions for init */
3160         set_section_ro_nx(mod->module_init,
3161                                 mod->init_text_size,
3162                                 mod->init_ro_size,
3163                                 mod->init_size);
3164 
3165         /* Mark state as coming so strong_try_module_get() ignores us,
3166          * but kallsyms etc. can see us. */
3167         mod->state = MODULE_STATE_COMING;
3168         mutex_unlock(&module_mutex);
3169 
3170         blocking_notifier_call_chain(&module_notify_list,
3171                                      MODULE_STATE_COMING, mod);
3172         return 0;
3173 
3174 out:
3175         mutex_unlock(&module_mutex);
3176         return err;
3177 }
3178 
3179 static int unknown_module_param_cb(char *param, char *val, const char *modname)
3180 {
3181         /* Check for magic 'dyndbg' arg */ 
3182         int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3183         if (ret != 0)
3184                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3185         return 0;
3186 }
3187 
3188 /* Allocate and load the module: note that size of section 0 is always
3189    zero, and we rely on this for optional sections. */
3190 static int load_module(struct load_info *info, const char __user *uargs,
3191                        int flags)
3192 {
3193         struct module *mod;
3194         long err;
3195         char *after_dashes;
3196 
3197         err = module_sig_check(info);
3198         if (err)
3199                 goto free_copy;
3200 
3201         err = elf_header_check(info);
3202         if (err)
3203                 goto free_copy;
3204 
3205         /* Figure out module layout, and allocate all the memory. */
3206         mod = layout_and_allocate(info, flags);
3207         if (IS_ERR(mod)) {
3208                 err = PTR_ERR(mod);
3209                 goto free_copy;
3210         }
3211 
3212         /* Reserve our place in the list. */
3213         err = add_unformed_module(mod);
3214         if (err)
3215                 goto free_module;
3216 
3217 #ifdef CONFIG_MODULE_SIG
3218         mod->sig_ok = info->sig_ok;
3219         if (!mod->sig_ok) {
3220                 pr_notice_once("%s: module verification failed: signature "
3221                                "and/or  required key missing - tainting "
3222                                "kernel\n", mod->name);
3223                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3224         }
3225 #endif
3226 
3227         /* To avoid stressing percpu allocator, do this once we're unique. */
3228         err = percpu_modalloc(mod, info);
3229         if (err)
3230                 goto unlink_mod;
3231 
3232         /* Now module is in final location, initialize linked lists, etc. */
3233         err = module_unload_init(mod);
3234         if (err)
3235                 goto unlink_mod;
3236 
3237         /* Now we've got everything in the final locations, we can
3238          * find optional sections. */
3239         err = find_module_sections(mod, info);
3240         if (err)
3241                 goto free_unload;
3242 
3243         err = check_module_license_and_versions(mod);
3244         if (err)
3245                 goto free_unload;
3246 
3247         /* Set up MODINFO_ATTR fields */
3248         setup_modinfo(mod, info);
3249 
3250         /* Fix up syms, so that st_value is a pointer to location. */
3251         err = simplify_symbols(mod, info);
3252         if (err < 0)
3253                 goto free_modinfo;
3254 
3255         err = apply_relocations(mod, info);
3256         if (err < 0)
3257                 goto free_modinfo;
3258 
3259         err = post_relocation(mod, info);
3260         if (err < 0)
3261                 goto free_modinfo;
3262 
3263         flush_module_icache(mod);
3264 
3265         /* Now copy in args */
3266         mod->args = strndup_user(uargs, ~0UL >> 1);
3267         if (IS_ERR(mod->args)) {
3268                 err = PTR_ERR(mod->args);
3269                 goto free_arch_cleanup;
3270         }
3271 
3272         dynamic_debug_setup(info->debug, info->num_debug);
3273 
3274         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3275         ftrace_module_init(mod);
3276 
3277         /* Finally it's fully formed, ready to start executing. */
3278         err = complete_formation(mod, info);
3279         if (err)
3280                 goto ddebug_cleanup;
3281 
3282         /* Module is ready to execute: parsing args may do that. */
3283         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3284                                   -32768, 32767, unknown_module_param_cb);
3285         if (IS_ERR(after_dashes)) {
3286                 err = PTR_ERR(after_dashes);
3287                 goto bug_cleanup;
3288         } else if (after_dashes) {
3289                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3290                        mod->name, after_dashes);
3291         }
3292 
3293         /* Link in to syfs. */
3294         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3295         if (err < 0)
3296                 goto bug_cleanup;
3297 
3298         /* Get rid of temporary copy. */
3299         free_copy(info);
3300 
3301         /* Done! */
3302         trace_module_load(mod);
3303 
3304         return do_init_module(mod);
3305 
3306  bug_cleanup:
3307         /* module_bug_cleanup needs module_mutex protection */
3308         mutex_lock(&module_mutex);
3309         module_bug_cleanup(mod);
3310         mutex_unlock(&module_mutex);
3311  ddebug_cleanup:
3312         dynamic_debug_remove(info->debug);
3313         synchronize_sched();
3314         kfree(mod->args);
3315  free_arch_cleanup:
3316         module_arch_cleanup(mod);
3317  free_modinfo:
3318         free_modinfo(mod);
3319  free_unload:
3320         module_unload_free(mod);
3321  unlink_mod:
3322         mutex_lock(&module_mutex);
3323         /* Unlink carefully: kallsyms could be walking list. */
3324         list_del_rcu(&mod->list);
3325         wake_up_all(&module_wq);
3326         mutex_unlock(&module_mutex);
3327  free_module:
3328         module_deallocate(mod, info);
3329  free_copy:
3330         free_copy(info);
3331         return err;
3332 }
3333 
3334 SYSCALL_DEFINE3(init_module, void __user *, umod,
3335                 unsigned long, len, const char __user *, uargs)
3336 {
3337         int err;
3338         struct load_info info = { };
3339 
3340         err = may_init_module();
3341         if (err)
3342                 return err;
3343 
3344         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3345                umod, len, uargs);
3346 
3347         err = copy_module_from_user(umod, len, &info);
3348         if (err)
3349                 return err;
3350 
3351         return load_module(&info, uargs, 0);
3352 }
3353 
3354 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3355 {
3356         int err;
3357         struct load_info info = { };
3358 
3359         err = may_init_module();
3360         if (err)
3361                 return err;
3362 
3363         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3364 
3365         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3366                       |MODULE_INIT_IGNORE_VERMAGIC))
3367                 return -EINVAL;
3368 
3369         err = copy_module_from_fd(fd, &info);
3370         if (err)
3371                 return err;
3372 
3373         return load_module(&info, uargs, flags);
3374 }
3375 
3376 static inline int within(unsigned long addr, void *start, unsigned long size)
3377 {
3378         return ((void *)addr >= start && (void *)addr < start + size);
3379 }
3380 
3381 #ifdef CONFIG_KALLSYMS
3382 /*
3383  * This ignores the intensely annoying "mapping symbols" found
3384  * in ARM ELF files: $a, $t and $d.
3385  */
3386 static inline int is_arm_mapping_symbol(const char *str)
3387 {
3388         return str[0] == '$' && strchr("atd", str[1])
3389                && (str[2] == '\0' || str[2] == '.');
3390 }
3391 
3392 static const char *get_ksymbol(struct module *mod,
3393                                unsigned long addr,
3394                                unsigned long *size,
3395                                unsigned long *offset)
3396 {
3397         unsigned int i, best = 0;
3398         unsigned long nextval;
3399 
3400         /* At worse, next value is at end of module */
3401         if (within_module_init(addr, mod))
3402                 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3403         else
3404                 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3405 
3406         /* Scan for closest preceding symbol, and next symbol. (ELF
3407            starts real symbols at 1). */
3408         for (i = 1; i < mod->num_symtab; i++) {
3409                 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3410                         continue;
3411 
3412                 /* We ignore unnamed symbols: they're uninformative
3413                  * and inserted at a whim. */
3414                 if (mod->symtab[i].st_value <= addr
3415                     && mod->symtab[i].st_value > mod->symtab[best].st_value
3416                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3417                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3418                         best = i;
3419                 if (mod->symtab[i].st_value > addr
3420                     && mod->symtab[i].st_value < nextval
3421                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3422                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3423                         nextval = mod->symtab[i].st_value;
3424         }
3425 
3426         if (!best)
3427                 return NULL;
3428 
3429         if (size)
3430                 *size = nextval - mod->symtab[best].st_value;
3431         if (offset)
3432                 *offset = addr - mod->symtab[best].st_value;
3433         return mod->strtab + mod->symtab[best].st_name;
3434 }
3435 
3436 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3437  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3438 const char *module_address_lookup(unsigned long addr,
3439                             unsigned long *size,
3440                             unsigned long *offset,
3441                             char **modname,
3442                             char *namebuf)
3443 {
3444         struct module *mod;
3445         const char *ret = NULL;
3446 
3447         preempt_disable();
3448         list_for_each_entry_rcu(mod, &modules, list) {
3449                 if (mod->state == MODULE_STATE_UNFORMED)
3450                         continue;
3451                 if (within_module_init(addr, mod) ||
3452                     within_module_core(addr, mod)) {
3453                         if (modname)
3454                                 *modname = mod->name;
3455                         ret = get_ksymbol(mod, addr, size, offset);
3456                         break;
3457                 }
3458         }
3459         /* Make a copy in here where it's safe */
3460         if (ret) {
3461                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3462                 ret = namebuf;
3463         }
3464         preempt_enable();
3465         return ret;
3466 }
3467 
3468 int lookup_module_symbol_name(unsigned long addr, char *symname)
3469 {
3470         struct module *mod;
3471 
3472         preempt_disable();
3473         list_for_each_entry_rcu(mod, &modules, list) {
3474                 if (mod->state == MODULE_STATE_UNFORMED)
3475                         continue;
3476                 if (within_module_init(addr, mod) ||
3477                     within_module_core(addr, mod)) {
3478                         const char *sym;
3479 
3480                         sym = get_ksymbol(mod, addr, NULL, NULL);
3481                         if (!sym)
3482                                 goto out;
3483                         strlcpy(symname, sym, KSYM_NAME_LEN);
3484                         preempt_enable();
3485                         return 0;
3486                 }
3487         }
3488 out:
3489         preempt_enable();
3490         return -ERANGE;
3491 }
3492 
3493 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3494                         unsigned long *offset, char *modname, char *name)
3495 {
3496         struct module *mod;
3497 
3498         preempt_disable();
3499         list_for_each_entry_rcu(mod, &modules, list) {
3500                 if (mod->state == MODULE_STATE_UNFORMED)
3501                         continue;
3502                 if (within_module_init(addr, mod) ||
3503                     within_module_core(addr, mod)) {
3504                         const char *sym;
3505 
3506                         sym = get_ksymbol(mod, addr, size, offset);
3507                         if (!sym)
3508                                 goto out;
3509                         if (modname)
3510                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3511                         if (name)
3512                                 strlcpy(name, sym, KSYM_NAME_LEN);
3513                         preempt_enable();
3514                         return 0;
3515                 }
3516         }
3517 out:
3518         preempt_enable();
3519         return -ERANGE;
3520 }
3521 
3522 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3523                         char *name, char *module_name, int *exported)
3524 {
3525         struct module *mod;
3526 
3527         preempt_disable();
3528         list_for_each_entry_rcu(mod, &modules, list) {
3529                 if (mod->state == MODULE_STATE_UNFORMED)
3530                         continue;
3531                 if (symnum < mod->num_symtab) {
3532                         *value = mod->symtab[symnum].st_value;
3533                         *type = mod->symtab[symnum].st_info;
3534                         strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3535                                 KSYM_NAME_LEN);
3536                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3537                         *exported = is_exported(name, *value, mod);
3538                         preempt_enable();
3539                         return 0;
3540                 }
3541                 symnum -= mod->num_symtab;
3542         }
3543         preempt_enable();
3544         return -ERANGE;
3545 }
3546 
3547 static unsigned long mod_find_symname(struct module *mod, const char *name)
3548 {
3549         unsigned int i;
3550 
3551         for (i = 0; i < mod->num_symtab; i++)
3552                 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3553                     mod->symtab[i].st_info != 'U')
3554                         return mod->symtab[i].st_value;
3555         return 0;
3556 }
3557 
3558 /* Look for this name: can be of form module:name. */
3559 unsigned long module_kallsyms_lookup_name(const char *name)
3560 {
3561         struct module *mod;
3562         char *colon;
3563         unsigned long ret = 0;
3564 
3565         /* Don't lock: we're in enough trouble already. */
3566         preempt_disable();
3567         if ((colon = strchr(name, ':')) != NULL) {
3568                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3569                         ret = mod_find_symname(mod, colon+1);
3570         } else {
3571                 list_for_each_entry_rcu(mod, &modules, list) {
3572                         if (mod->state == MODULE_STATE_UNFORMED)
3573                                 continue;
3574                         if ((ret = mod_find_symname(mod, name)) != 0)
3575                                 break;
3576                 }
3577         }
3578         preempt_enable();
3579         return ret;
3580 }
3581 
3582 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3583                                              struct module *, unsigned long),
3584                                    void *data)
3585 {
3586         struct module *mod;
3587         unsigned int i;
3588         int ret;
3589 
3590         list_for_each_entry(mod, &modules, list) {
3591                 if (mod->state == MODULE_STATE_UNFORMED)
3592                         continue;
3593                 for (i = 0; i < mod->num_symtab; i++) {
3594                         ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3595                                  mod, mod->symtab[i].st_value);
3596                         if (ret != 0)
3597                                 return ret;
3598                 }
3599         }
3600         return 0;
3601 }
3602 #endif /* CONFIG_KALLSYMS */
3603 
3604 static char *module_flags(struct module *mod, char *buf)
3605 {
3606         int bx = 0;
3607 
3608         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3609         if (mod->taints ||
3610             mod->state == MODULE_STATE_GOING ||
3611             mod->state == MODULE_STATE_COMING) {
3612                 buf[bx++] = '(';
3613                 bx += module_flags_taint(mod, buf + bx);
3614                 /* Show a - for module-is-being-unloaded */
3615                 if (mod->state == MODULE_STATE_GOING)
3616                         buf[bx++] = '-';
3617                 /* Show a + for module-is-being-loaded */
3618                 if (mod->state == MODULE_STATE_COMING)
3619                         buf[bx++] = '+';
3620                 buf[bx++] = ')';
3621         }
3622         buf[bx] = '\0';
3623 
3624         return buf;
3625 }
3626 
3627 #ifdef CONFIG_PROC_FS
3628 /* Called by the /proc file system to return a list of modules. */
3629 static void *m_start(struct seq_file *m, loff_t *pos)
3630 {
3631         mutex_lock(&module_mutex);
3632         return seq_list_start(&modules, *pos);
3633 }
3634 
3635 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3636 {
3637         return seq_list_next(p, &modules, pos);
3638 }
3639 
3640 static void m_stop(struct seq_file *m, void *p)
3641 {
3642         mutex_unlock(&module_mutex);
3643 }
3644 
3645 static int m_show(struct seq_file *m, void *p)
3646 {
3647         struct module *mod = list_entry(p, struct module, list);
3648         char buf[8];
3649 
3650         /* We always ignore unformed modules. */
3651         if (mod->state == MODULE_STATE_UNFORMED)
3652                 return 0;
3653 
3654         seq_printf(m, "%s %u",
3655                    mod->name, mod->init_size + mod->core_size);
3656         print_unload_info(m, mod);
3657 
3658         /* Informative for users. */
3659         seq_printf(m, " %s",
3660                    mod->state == MODULE_STATE_GOING ? "Unloading":
3661                    mod->state == MODULE_STATE_COMING ? "Loading":
3662                    "Live");
3663         /* Used by oprofile and other similar tools. */
3664         seq_printf(m, " 0x%pK", mod->module_core);
3665 
3666         /* Taints info */
3667         if (mod->taints)
3668                 seq_printf(m, " %s", module_flags(mod, buf));
3669 
3670         seq_printf(m, "\n");
3671         return 0;
3672 }
3673 
3674 /* Format: modulename size refcount deps address
3675 
3676    Where refcount is a number or -, and deps is a comma-separated list
3677    of depends or -.
3678 */
3679 static const struct seq_operations modules_op = {
3680         .start  = m_start,
3681         .next   = m_next,
3682         .stop   = m_stop,
3683         .show   = m_show
3684 };
3685 
3686 static int modules_open(struct inode *inode, struct file *file)
3687 {
3688         return seq_open(file, &modules_op);
3689 }
3690 
3691 static const struct file_operations proc_modules_operations = {
3692         .open           = modules_open,
3693         .read           = seq_read,
3694         .llseek         = seq_lseek,
3695         .release        = seq_release,
3696 };
3697 
3698 static int __init proc_modules_init(void)
3699 {
3700         proc_create("modules", 0, NULL, &proc_modules_operations);
3701         return 0;
3702 }
3703 module_init(proc_modules_init);
3704 #endif
3705 
3706 /* Given an address, look for it in the module exception tables. */
3707 const struct exception_table_entry *search_module_extables(unsigned long addr)
3708 {
3709         const struct exception_table_entry *e = NULL;
3710         struct module *mod;
3711 
3712         preempt_disable();
3713         list_for_each_entry_rcu(mod, &modules, list) {
3714                 if (mod->state == MODULE_STATE_UNFORMED)
3715                         continue;
3716                 if (mod->num_exentries == 0)
3717                         continue;
3718 
3719                 e = search_extable(mod->extable,
3720                                    mod->extable + mod->num_exentries - 1,
3721                                    addr);
3722                 if (e)
3723                         break;
3724         }
3725         preempt_enable();
3726 
3727         /* Now, if we found one, we are running inside it now, hence
3728            we cannot unload the module, hence no refcnt needed. */
3729         return e;
3730 }
3731 
3732 /*
3733  * is_module_address - is this address inside a module?
3734  * @addr: the address to check.
3735  *
3736  * See is_module_text_address() if you simply want to see if the address
3737  * is code (not data).
3738  */
3739 bool is_module_address(unsigned long addr)
3740 {
3741         bool ret;
3742 
3743         preempt_disable();
3744         ret = __module_address(addr) != NULL;
3745         preempt_enable();
3746 
3747         return ret;
3748 }
3749 
3750 /*
3751  * __module_address - get the module which contains an address.
3752  * @addr: the address.
3753  *
3754  * Must be called with preempt disabled or module mutex held so that
3755  * module doesn't get freed during this.
3756  */
3757 struct module *__module_address(unsigned long addr)
3758 {
3759         struct module *mod;
3760 
3761         if (addr < module_addr_min || addr > module_addr_max)
3762                 return NULL;
3763 
3764         list_for_each_entry_rcu(mod, &modules, list) {
3765                 if (mod->state == MODULE_STATE_UNFORMED)
3766                         continue;
3767                 if (within_module_core(addr, mod)
3768                     || within_module_init(addr, mod))
3769                         return mod;
3770         }
3771         return NULL;
3772 }
3773 EXPORT_SYMBOL_GPL(__module_address);
3774 
3775 /*
3776  * is_module_text_address - is this address inside module code?
3777  * @addr: the address to check.
3778  *
3779  * See is_module_address() if you simply want to see if the address is
3780  * anywhere in a module.  See kernel_text_address() for testing if an
3781  * address corresponds to kernel or module code.
3782  */
3783 bool is_module_text_address(unsigned long addr)
3784 {
3785         bool ret;
3786 
3787         preempt_disable();
3788         ret = __module_text_address(addr) != NULL;
3789         preempt_enable();
3790 
3791         return ret;
3792 }
3793 
3794 /*
3795  * __module_text_address - get the module whose code contains an address.
3796  * @addr: the address.
3797  *
3798  * Must be called with preempt disabled or module mutex held so that
3799  * module doesn't get freed during this.
3800  */
3801 struct module *__module_text_address(unsigned long addr)
3802 {
3803         struct module *mod = __module_address(addr);
3804         if (mod) {
3805                 /* Make sure it's within the text section. */
3806                 if (!within(addr, mod->module_init, mod->init_text_size)
3807                     && !within(addr, mod->module_core, mod->core_text_size))
3808                         mod = NULL;
3809         }
3810         return mod;
3811 }
3812 EXPORT_SYMBOL_GPL(__module_text_address);
3813 
3814 /* Don't grab lock, we're oopsing. */
3815 void print_modules(void)
3816 {
3817         struct module *mod;
3818         char buf[8];
3819 
3820         printk(KERN_DEFAULT "Modules linked in:");
3821         /* Most callers should already have preempt disabled, but make sure */
3822         preempt_disable();
3823         list_for_each_entry_rcu(mod, &modules, list) {
3824                 if (mod->state == MODULE_STATE_UNFORMED)
3825                         continue;
3826                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
3827         }
3828         preempt_enable();
3829         if (last_unloaded_module[0])
3830                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
3831         pr_cont("\n");
3832 }
3833 
3834 #ifdef CONFIG_MODVERSIONS
3835 /* Generate the signature for all relevant module structures here.
3836  * If these change, we don't want to try to parse the module. */
3837 void module_layout(struct module *mod,
3838                    struct modversion_info *ver,
3839                    struct kernel_param *kp,
3840                    struct kernel_symbol *ks,
3841                    struct tracepoint * const *tp)
3842 {
3843 }
3844 EXPORT_SYMBOL(module_layout);
3845 #endif
3846 

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