Version:  2.0.40 2.2.26 2.4.37 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 3.17 3.18

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 <uapi/linux/module.h>
 64 #include "module-internal.h"
 65 
 66 #define CREATE_TRACE_POINTS
 67 #include <trace/events/module.h>
 68 
 69 #ifndef ARCH_SHF_SMALL
 70 #define ARCH_SHF_SMALL 0
 71 #endif
 72 
 73 /*
 74  * Modules' sections will be aligned on page boundaries
 75  * to ensure complete separation of code and data, but
 76  * only when CONFIG_DEBUG_SET_MODULE_RONX=y
 77  */
 78 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 79 # define debug_align(X) ALIGN(X, PAGE_SIZE)
 80 #else
 81 # define debug_align(X) (X)
 82 #endif
 83 
 84 /*
 85  * Given BASE and SIZE this macro calculates the number of pages the
 86  * memory regions occupies
 87  */
 88 #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?         \
 89                 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
 90                          PFN_DOWN((unsigned long)BASE) + 1)     \
 91                 : (0UL))
 92 
 93 /* If this is set, the section belongs in the init part of the module */
 94 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
 95 
 96 /*
 97  * Mutex protects:
 98  * 1) List of modules (also safely readable with preempt_disable),
 99  * 2) module_use links,
100  * 3) module_addr_min/module_addr_max.
101  * (delete uses stop_machine/add uses RCU list operations). */
102 DEFINE_MUTEX(module_mutex);
103 EXPORT_SYMBOL_GPL(module_mutex);
104 static LIST_HEAD(modules);
105 #ifdef CONFIG_KGDB_KDB
106 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
107 #endif /* CONFIG_KGDB_KDB */
108 
109 #ifdef CONFIG_MODULE_SIG
110 #ifdef CONFIG_MODULE_SIG_FORCE
111 static bool sig_enforce = true;
112 #else
113 static bool sig_enforce = false;
114 
115 static int param_set_bool_enable_only(const char *val,
116                                       const struct kernel_param *kp)
117 {
118         int err;
119         bool test;
120         struct kernel_param dummy_kp = *kp;
121 
122         dummy_kp.arg = &test;
123 
124         err = param_set_bool(val, &dummy_kp);
125         if (err)
126                 return err;
127 
128         /* Don't let them unset it once it's set! */
129         if (!test && sig_enforce)
130                 return -EROFS;
131 
132         if (test)
133                 sig_enforce = true;
134         return 0;
135 }
136 
137 static const struct kernel_param_ops param_ops_bool_enable_only = {
138         .flags = KERNEL_PARAM_OPS_FL_NOARG,
139         .set = param_set_bool_enable_only,
140         .get = param_get_bool,
141 };
142 #define param_check_bool_enable_only param_check_bool
143 
144 module_param(sig_enforce, bool_enable_only, 0644);
145 #endif /* !CONFIG_MODULE_SIG_FORCE */
146 #endif /* CONFIG_MODULE_SIG */
147 
148 /* Block module loading/unloading? */
149 int modules_disabled = 0;
150 core_param(nomodule, modules_disabled, bint, 0);
151 
152 /* Waiting for a module to finish initializing? */
153 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
154 
155 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
156 
157 /* Bounds of module allocation, for speeding __module_address.
158  * Protected by module_mutex. */
159 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
160 
161 int register_module_notifier(struct notifier_block * nb)
162 {
163         return blocking_notifier_chain_register(&module_notify_list, nb);
164 }
165 EXPORT_SYMBOL(register_module_notifier);
166 
167 int unregister_module_notifier(struct notifier_block * nb)
168 {
169         return blocking_notifier_chain_unregister(&module_notify_list, nb);
170 }
171 EXPORT_SYMBOL(unregister_module_notifier);
172 
173 struct load_info {
174         Elf_Ehdr *hdr;
175         unsigned long len;
176         Elf_Shdr *sechdrs;
177         char *secstrings, *strtab;
178         unsigned long symoffs, stroffs;
179         struct _ddebug *debug;
180         unsigned int num_debug;
181         bool sig_ok;
182         struct {
183                 unsigned int sym, str, mod, vers, info, pcpu;
184         } index;
185 };
186 
187 /* We require a truly strong try_module_get(): 0 means failure due to
188    ongoing or failed initialization etc. */
189 static inline int strong_try_module_get(struct module *mod)
190 {
191         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
192         if (mod && mod->state == MODULE_STATE_COMING)
193                 return -EBUSY;
194         if (try_module_get(mod))
195                 return 0;
196         else
197                 return -ENOENT;
198 }
199 
200 static inline void add_taint_module(struct module *mod, unsigned flag,
201                                     enum lockdep_ok lockdep_ok)
202 {
203         add_taint(flag, lockdep_ok);
204         mod->taints |= (1U << flag);
205 }
206 
207 /*
208  * A thread that wants to hold a reference to a module only while it
209  * is running can call this to safely exit.  nfsd and lockd use this.
210  */
211 void __module_put_and_exit(struct module *mod, long code)
212 {
213         module_put(mod);
214         do_exit(code);
215 }
216 EXPORT_SYMBOL(__module_put_and_exit);
217 
218 /* Find a module section: 0 means not found. */
219 static unsigned int find_sec(const struct load_info *info, const char *name)
220 {
221         unsigned int i;
222 
223         for (i = 1; i < info->hdr->e_shnum; i++) {
224                 Elf_Shdr *shdr = &info->sechdrs[i];
225                 /* Alloc bit cleared means "ignore it." */
226                 if ((shdr->sh_flags & SHF_ALLOC)
227                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
228                         return i;
229         }
230         return 0;
231 }
232 
233 /* Find a module section, or NULL. */
234 static void *section_addr(const struct load_info *info, const char *name)
235 {
236         /* Section 0 has sh_addr 0. */
237         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
238 }
239 
240 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
241 static void *section_objs(const struct load_info *info,
242                           const char *name,
243                           size_t object_size,
244                           unsigned int *num)
245 {
246         unsigned int sec = find_sec(info, name);
247 
248         /* Section 0 has sh_addr 0 and sh_size 0. */
249         *num = info->sechdrs[sec].sh_size / object_size;
250         return (void *)info->sechdrs[sec].sh_addr;
251 }
252 
253 /* Provided by the linker */
254 extern const struct kernel_symbol __start___ksymtab[];
255 extern const struct kernel_symbol __stop___ksymtab[];
256 extern const struct kernel_symbol __start___ksymtab_gpl[];
257 extern const struct kernel_symbol __stop___ksymtab_gpl[];
258 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
259 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
260 extern const unsigned long __start___kcrctab[];
261 extern const unsigned long __start___kcrctab_gpl[];
262 extern const unsigned long __start___kcrctab_gpl_future[];
263 #ifdef CONFIG_UNUSED_SYMBOLS
264 extern const struct kernel_symbol __start___ksymtab_unused[];
265 extern const struct kernel_symbol __stop___ksymtab_unused[];
266 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
267 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
268 extern const unsigned long __start___kcrctab_unused[];
269 extern const unsigned long __start___kcrctab_unused_gpl[];
270 #endif
271 
272 #ifndef CONFIG_MODVERSIONS
273 #define symversion(base, idx) NULL
274 #else
275 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
276 #endif
277 
278 static bool each_symbol_in_section(const struct symsearch *arr,
279                                    unsigned int arrsize,
280                                    struct module *owner,
281                                    bool (*fn)(const struct symsearch *syms,
282                                               struct module *owner,
283                                               void *data),
284                                    void *data)
285 {
286         unsigned int j;
287 
288         for (j = 0; j < arrsize; j++) {
289                 if (fn(&arr[j], owner, data))
290                         return true;
291         }
292 
293         return false;
294 }
295 
296 /* Returns true as soon as fn returns true, otherwise false. */
297 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
298                                     struct module *owner,
299                                     void *data),
300                          void *data)
301 {
302         struct module *mod;
303         static const struct symsearch arr[] = {
304                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
305                   NOT_GPL_ONLY, false },
306                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
307                   __start___kcrctab_gpl,
308                   GPL_ONLY, false },
309                 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
310                   __start___kcrctab_gpl_future,
311                   WILL_BE_GPL_ONLY, false },
312 #ifdef CONFIG_UNUSED_SYMBOLS
313                 { __start___ksymtab_unused, __stop___ksymtab_unused,
314                   __start___kcrctab_unused,
315                   NOT_GPL_ONLY, true },
316                 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
317                   __start___kcrctab_unused_gpl,
318                   GPL_ONLY, true },
319 #endif
320         };
321 
322         if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
323                 return true;
324 
325         list_for_each_entry_rcu(mod, &modules, list) {
326                 struct symsearch arr[] = {
327                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
328                           NOT_GPL_ONLY, false },
329                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
330                           mod->gpl_crcs,
331                           GPL_ONLY, false },
332                         { mod->gpl_future_syms,
333                           mod->gpl_future_syms + mod->num_gpl_future_syms,
334                           mod->gpl_future_crcs,
335                           WILL_BE_GPL_ONLY, false },
336 #ifdef CONFIG_UNUSED_SYMBOLS
337                         { mod->unused_syms,
338                           mod->unused_syms + mod->num_unused_syms,
339                           mod->unused_crcs,
340                           NOT_GPL_ONLY, true },
341                         { mod->unused_gpl_syms,
342                           mod->unused_gpl_syms + mod->num_unused_gpl_syms,
343                           mod->unused_gpl_crcs,
344                           GPL_ONLY, true },
345 #endif
346                 };
347 
348                 if (mod->state == MODULE_STATE_UNFORMED)
349                         continue;
350 
351                 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
352                         return true;
353         }
354         return false;
355 }
356 EXPORT_SYMBOL_GPL(each_symbol_section);
357 
358 struct find_symbol_arg {
359         /* Input */
360         const char *name;
361         bool gplok;
362         bool warn;
363 
364         /* Output */
365         struct module *owner;
366         const unsigned long *crc;
367         const struct kernel_symbol *sym;
368 };
369 
370 static bool check_symbol(const struct symsearch *syms,
371                                  struct module *owner,
372                                  unsigned int symnum, void *data)
373 {
374         struct find_symbol_arg *fsa = data;
375 
376         if (!fsa->gplok) {
377                 if (syms->licence == GPL_ONLY)
378                         return false;
379                 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
380                         pr_warn("Symbol %s is being used by a non-GPL module, "
381                                 "which will not be allowed in the future\n",
382                                 fsa->name);
383                 }
384         }
385 
386 #ifdef CONFIG_UNUSED_SYMBOLS
387         if (syms->unused && fsa->warn) {
388                 pr_warn("Symbol %s is marked as UNUSED, however this module is "
389                         "using it.\n", fsa->name);
390                 pr_warn("This symbol will go away in the future.\n");
391                 pr_warn("Please evalute if this is the right api to use and if "
392                         "it really is, submit a report the linux kernel "
393                         "mailinglist together with submitting your code for "
394                         "inclusion.\n");
395         }
396 #endif
397 
398         fsa->owner = owner;
399         fsa->crc = symversion(syms->crcs, symnum);
400         fsa->sym = &syms->start[symnum];
401         return true;
402 }
403 
404 static int cmp_name(const void *va, const void *vb)
405 {
406         const char *a;
407         const struct kernel_symbol *b;
408         a = va; b = vb;
409         return strcmp(a, b->name);
410 }
411 
412 static bool find_symbol_in_section(const struct symsearch *syms,
413                                    struct module *owner,
414                                    void *data)
415 {
416         struct find_symbol_arg *fsa = data;
417         struct kernel_symbol *sym;
418 
419         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
420                         sizeof(struct kernel_symbol), cmp_name);
421 
422         if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
423                 return true;
424 
425         return false;
426 }
427 
428 /* Find a symbol and return it, along with, (optional) crc and
429  * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
430 const struct kernel_symbol *find_symbol(const char *name,
431                                         struct module **owner,
432                                         const unsigned long **crc,
433                                         bool gplok,
434                                         bool warn)
435 {
436         struct find_symbol_arg fsa;
437 
438         fsa.name = name;
439         fsa.gplok = gplok;
440         fsa.warn = warn;
441 
442         if (each_symbol_section(find_symbol_in_section, &fsa)) {
443                 if (owner)
444                         *owner = fsa.owner;
445                 if (crc)
446                         *crc = fsa.crc;
447                 return fsa.sym;
448         }
449 
450         pr_debug("Failed to find symbol %s\n", name);
451         return NULL;
452 }
453 EXPORT_SYMBOL_GPL(find_symbol);
454 
455 /* Search for module by name: must hold module_mutex. */
456 static struct module *find_module_all(const char *name, size_t len,
457                                       bool even_unformed)
458 {
459         struct module *mod;
460 
461         list_for_each_entry(mod, &modules, list) {
462                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
463                         continue;
464                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
465                         return mod;
466         }
467         return NULL;
468 }
469 
470 struct module *find_module(const char *name)
471 {
472         return find_module_all(name, strlen(name), false);
473 }
474 EXPORT_SYMBOL_GPL(find_module);
475 
476 #ifdef CONFIG_SMP
477 
478 static inline void __percpu *mod_percpu(struct module *mod)
479 {
480         return mod->percpu;
481 }
482 
483 static int percpu_modalloc(struct module *mod, struct load_info *info)
484 {
485         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
486         unsigned long align = pcpusec->sh_addralign;
487 
488         if (!pcpusec->sh_size)
489                 return 0;
490 
491         if (align > PAGE_SIZE) {
492                 pr_warn("%s: per-cpu alignment %li > %li\n",
493                         mod->name, align, PAGE_SIZE);
494                 align = PAGE_SIZE;
495         }
496 
497         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
498         if (!mod->percpu) {
499                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
500                         mod->name, (unsigned long)pcpusec->sh_size);
501                 return -ENOMEM;
502         }
503         mod->percpu_size = pcpusec->sh_size;
504         return 0;
505 }
506 
507 static void percpu_modfree(struct module *mod)
508 {
509         free_percpu(mod->percpu);
510 }
511 
512 static unsigned int find_pcpusec(struct load_info *info)
513 {
514         return find_sec(info, ".data..percpu");
515 }
516 
517 static void percpu_modcopy(struct module *mod,
518                            const void *from, unsigned long size)
519 {
520         int cpu;
521 
522         for_each_possible_cpu(cpu)
523                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
524 }
525 
526 /**
527  * is_module_percpu_address - test whether address is from module static percpu
528  * @addr: address to test
529  *
530  * Test whether @addr belongs to module static percpu area.
531  *
532  * RETURNS:
533  * %true if @addr is from module static percpu area
534  */
535 bool is_module_percpu_address(unsigned long addr)
536 {
537         struct module *mod;
538         unsigned int cpu;
539 
540         preempt_disable();
541 
542         list_for_each_entry_rcu(mod, &modules, list) {
543                 if (mod->state == MODULE_STATE_UNFORMED)
544                         continue;
545                 if (!mod->percpu_size)
546                         continue;
547                 for_each_possible_cpu(cpu) {
548                         void *start = per_cpu_ptr(mod->percpu, cpu);
549 
550                         if ((void *)addr >= start &&
551                             (void *)addr < start + mod->percpu_size) {
552                                 preempt_enable();
553                                 return true;
554                         }
555                 }
556         }
557 
558         preempt_enable();
559         return false;
560 }
561 
562 #else /* ... !CONFIG_SMP */
563 
564 static inline void __percpu *mod_percpu(struct module *mod)
565 {
566         return NULL;
567 }
568 static int percpu_modalloc(struct module *mod, struct load_info *info)
569 {
570         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
571         if (info->sechdrs[info->index.pcpu].sh_size != 0)
572                 return -ENOMEM;
573         return 0;
574 }
575 static inline void percpu_modfree(struct module *mod)
576 {
577 }
578 static unsigned int find_pcpusec(struct load_info *info)
579 {
580         return 0;
581 }
582 static inline void percpu_modcopy(struct module *mod,
583                                   const void *from, unsigned long size)
584 {
585         /* pcpusec should be 0, and size of that section should be 0. */
586         BUG_ON(size != 0);
587 }
588 bool is_module_percpu_address(unsigned long addr)
589 {
590         return false;
591 }
592 
593 #endif /* CONFIG_SMP */
594 
595 #define MODINFO_ATTR(field)     \
596 static void setup_modinfo_##field(struct module *mod, const char *s)  \
597 {                                                                     \
598         mod->field = kstrdup(s, GFP_KERNEL);                          \
599 }                                                                     \
600 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
601                         struct module_kobject *mk, char *buffer)      \
602 {                                                                     \
603         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
604 }                                                                     \
605 static int modinfo_##field##_exists(struct module *mod)               \
606 {                                                                     \
607         return mod->field != NULL;                                    \
608 }                                                                     \
609 static void free_modinfo_##field(struct module *mod)                  \
610 {                                                                     \
611         kfree(mod->field);                                            \
612         mod->field = NULL;                                            \
613 }                                                                     \
614 static struct module_attribute modinfo_##field = {                    \
615         .attr = { .name = __stringify(field), .mode = 0444 },         \
616         .show = show_modinfo_##field,                                 \
617         .setup = setup_modinfo_##field,                               \
618         .test = modinfo_##field##_exists,                             \
619         .free = free_modinfo_##field,                                 \
620 };
621 
622 MODINFO_ATTR(version);
623 MODINFO_ATTR(srcversion);
624 
625 static char last_unloaded_module[MODULE_NAME_LEN+1];
626 
627 #ifdef CONFIG_MODULE_UNLOAD
628 
629 EXPORT_TRACEPOINT_SYMBOL(module_get);
630 
631 /* Init the unload section of the module. */
632 static int module_unload_init(struct module *mod)
633 {
634         mod->refptr = alloc_percpu(struct module_ref);
635         if (!mod->refptr)
636                 return -ENOMEM;
637 
638         INIT_LIST_HEAD(&mod->source_list);
639         INIT_LIST_HEAD(&mod->target_list);
640 
641         /* Hold reference count during initialization. */
642         raw_cpu_write(mod->refptr->incs, 1);
643 
644         return 0;
645 }
646 
647 /* Does a already use b? */
648 static int already_uses(struct module *a, struct module *b)
649 {
650         struct module_use *use;
651 
652         list_for_each_entry(use, &b->source_list, source_list) {
653                 if (use->source == a) {
654                         pr_debug("%s uses %s!\n", a->name, b->name);
655                         return 1;
656                 }
657         }
658         pr_debug("%s does not use %s!\n", a->name, b->name);
659         return 0;
660 }
661 
662 /*
663  * Module a uses b
664  *  - we add 'a' as a "source", 'b' as a "target" of module use
665  *  - the module_use is added to the list of 'b' sources (so
666  *    'b' can walk the list to see who sourced them), and of 'a'
667  *    targets (so 'a' can see what modules it targets).
668  */
669 static int add_module_usage(struct module *a, struct module *b)
670 {
671         struct module_use *use;
672 
673         pr_debug("Allocating new usage for %s.\n", a->name);
674         use = kmalloc(sizeof(*use), GFP_ATOMIC);
675         if (!use) {
676                 pr_warn("%s: out of memory loading\n", a->name);
677                 return -ENOMEM;
678         }
679 
680         use->source = a;
681         use->target = b;
682         list_add(&use->source_list, &b->source_list);
683         list_add(&use->target_list, &a->target_list);
684         return 0;
685 }
686 
687 /* Module a uses b: caller needs module_mutex() */
688 int ref_module(struct module *a, struct module *b)
689 {
690         int err;
691 
692         if (b == NULL || already_uses(a, b))
693                 return 0;
694 
695         /* If module isn't available, we fail. */
696         err = strong_try_module_get(b);
697         if (err)
698                 return err;
699 
700         err = add_module_usage(a, b);
701         if (err) {
702                 module_put(b);
703                 return err;
704         }
705         return 0;
706 }
707 EXPORT_SYMBOL_GPL(ref_module);
708 
709 /* Clear the unload stuff of the module. */
710 static void module_unload_free(struct module *mod)
711 {
712         struct module_use *use, *tmp;
713 
714         mutex_lock(&module_mutex);
715         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
716                 struct module *i = use->target;
717                 pr_debug("%s unusing %s\n", mod->name, i->name);
718                 module_put(i);
719                 list_del(&use->source_list);
720                 list_del(&use->target_list);
721                 kfree(use);
722         }
723         mutex_unlock(&module_mutex);
724 
725         free_percpu(mod->refptr);
726 }
727 
728 #ifdef CONFIG_MODULE_FORCE_UNLOAD
729 static inline int try_force_unload(unsigned int flags)
730 {
731         int ret = (flags & O_TRUNC);
732         if (ret)
733                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
734         return ret;
735 }
736 #else
737 static inline int try_force_unload(unsigned int flags)
738 {
739         return 0;
740 }
741 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
742 
743 struct stopref
744 {
745         struct module *mod;
746         int flags;
747         int *forced;
748 };
749 
750 /* Whole machine is stopped with interrupts off when this runs. */
751 static int __try_stop_module(void *_sref)
752 {
753         struct stopref *sref = _sref;
754 
755         /* If it's not unused, quit unless we're forcing. */
756         if (module_refcount(sref->mod) != 0) {
757                 if (!(*sref->forced = try_force_unload(sref->flags)))
758                         return -EWOULDBLOCK;
759         }
760 
761         /* Mark it as dying. */
762         sref->mod->state = MODULE_STATE_GOING;
763         return 0;
764 }
765 
766 static int try_stop_module(struct module *mod, int flags, int *forced)
767 {
768         struct stopref sref = { mod, flags, forced };
769 
770         return stop_machine(__try_stop_module, &sref, NULL);
771 }
772 
773 unsigned long module_refcount(struct module *mod)
774 {
775         unsigned long incs = 0, decs = 0;
776         int cpu;
777 
778         for_each_possible_cpu(cpu)
779                 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
780         /*
781          * ensure the incs are added up after the decs.
782          * module_put ensures incs are visible before decs with smp_wmb.
783          *
784          * This 2-count scheme avoids the situation where the refcount
785          * for CPU0 is read, then CPU0 increments the module refcount,
786          * then CPU1 drops that refcount, then the refcount for CPU1 is
787          * read. We would record a decrement but not its corresponding
788          * increment so we would see a low count (disaster).
789          *
790          * Rare situation? But module_refcount can be preempted, and we
791          * might be tallying up 4096+ CPUs. So it is not impossible.
792          */
793         smp_rmb();
794         for_each_possible_cpu(cpu)
795                 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
796         return incs - decs;
797 }
798 EXPORT_SYMBOL(module_refcount);
799 
800 /* This exists whether we can unload or not */
801 static void free_module(struct module *mod);
802 
803 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
804                 unsigned int, flags)
805 {
806         struct module *mod;
807         char name[MODULE_NAME_LEN];
808         int ret, forced = 0;
809 
810         if (!capable(CAP_SYS_MODULE) || modules_disabled)
811                 return -EPERM;
812 
813         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
814                 return -EFAULT;
815         name[MODULE_NAME_LEN-1] = '\0';
816 
817         if (mutex_lock_interruptible(&module_mutex) != 0)
818                 return -EINTR;
819 
820         mod = find_module(name);
821         if (!mod) {
822                 ret = -ENOENT;
823                 goto out;
824         }
825 
826         if (!list_empty(&mod->source_list)) {
827                 /* Other modules depend on us: get rid of them first. */
828                 ret = -EWOULDBLOCK;
829                 goto out;
830         }
831 
832         /* Doing init or already dying? */
833         if (mod->state != MODULE_STATE_LIVE) {
834                 /* FIXME: if (force), slam module count damn the torpedoes */
835                 pr_debug("%s already dying\n", mod->name);
836                 ret = -EBUSY;
837                 goto out;
838         }
839 
840         /* If it has an init func, it must have an exit func to unload */
841         if (mod->init && !mod->exit) {
842                 forced = try_force_unload(flags);
843                 if (!forced) {
844                         /* This module can't be removed */
845                         ret = -EBUSY;
846                         goto out;
847                 }
848         }
849 
850         /* Stop the machine so refcounts can't move and disable module. */
851         ret = try_stop_module(mod, flags, &forced);
852         if (ret != 0)
853                 goto out;
854 
855         mutex_unlock(&module_mutex);
856         /* Final destruction now no one is using it. */
857         if (mod->exit != NULL)
858                 mod->exit();
859         blocking_notifier_call_chain(&module_notify_list,
860                                      MODULE_STATE_GOING, mod);
861         async_synchronize_full();
862 
863         /* Store the name of the last unloaded module for diagnostic purposes */
864         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
865 
866         free_module(mod);
867         return 0;
868 out:
869         mutex_unlock(&module_mutex);
870         return ret;
871 }
872 
873 static inline void print_unload_info(struct seq_file *m, struct module *mod)
874 {
875         struct module_use *use;
876         int printed_something = 0;
877 
878         seq_printf(m, " %lu ", module_refcount(mod));
879 
880         /* Always include a trailing , so userspace can differentiate
881            between this and the old multi-field proc format. */
882         list_for_each_entry(use, &mod->source_list, source_list) {
883                 printed_something = 1;
884                 seq_printf(m, "%s,", use->source->name);
885         }
886 
887         if (mod->init != NULL && mod->exit == NULL) {
888                 printed_something = 1;
889                 seq_printf(m, "[permanent],");
890         }
891 
892         if (!printed_something)
893                 seq_printf(m, "-");
894 }
895 
896 void __symbol_put(const char *symbol)
897 {
898         struct module *owner;
899 
900         preempt_disable();
901         if (!find_symbol(symbol, &owner, NULL, true, false))
902                 BUG();
903         module_put(owner);
904         preempt_enable();
905 }
906 EXPORT_SYMBOL(__symbol_put);
907 
908 /* Note this assumes addr is a function, which it currently always is. */
909 void symbol_put_addr(void *addr)
910 {
911         struct module *modaddr;
912         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
913 
914         if (core_kernel_text(a))
915                 return;
916 
917         /* module_text_address is safe here: we're supposed to have reference
918          * to module from symbol_get, so it can't go away. */
919         modaddr = __module_text_address(a);
920         BUG_ON(!modaddr);
921         module_put(modaddr);
922 }
923 EXPORT_SYMBOL_GPL(symbol_put_addr);
924 
925 static ssize_t show_refcnt(struct module_attribute *mattr,
926                            struct module_kobject *mk, char *buffer)
927 {
928         return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
929 }
930 
931 static struct module_attribute modinfo_refcnt =
932         __ATTR(refcnt, 0444, show_refcnt, NULL);
933 
934 void __module_get(struct module *module)
935 {
936         if (module) {
937                 preempt_disable();
938                 __this_cpu_inc(module->refptr->incs);
939                 trace_module_get(module, _RET_IP_);
940                 preempt_enable();
941         }
942 }
943 EXPORT_SYMBOL(__module_get);
944 
945 bool try_module_get(struct module *module)
946 {
947         bool ret = true;
948 
949         if (module) {
950                 preempt_disable();
951 
952                 if (likely(module_is_live(module))) {
953                         __this_cpu_inc(module->refptr->incs);
954                         trace_module_get(module, _RET_IP_);
955                 } else
956                         ret = false;
957 
958                 preempt_enable();
959         }
960         return ret;
961 }
962 EXPORT_SYMBOL(try_module_get);
963 
964 void module_put(struct module *module)
965 {
966         if (module) {
967                 preempt_disable();
968                 smp_wmb(); /* see comment in module_refcount */
969                 __this_cpu_inc(module->refptr->decs);
970 
971                 trace_module_put(module, _RET_IP_);
972                 preempt_enable();
973         }
974 }
975 EXPORT_SYMBOL(module_put);
976 
977 #else /* !CONFIG_MODULE_UNLOAD */
978 static inline void print_unload_info(struct seq_file *m, struct module *mod)
979 {
980         /* We don't know the usage count, or what modules are using. */
981         seq_printf(m, " - -");
982 }
983 
984 static inline void module_unload_free(struct module *mod)
985 {
986 }
987 
988 int ref_module(struct module *a, struct module *b)
989 {
990         return strong_try_module_get(b);
991 }
992 EXPORT_SYMBOL_GPL(ref_module);
993 
994 static inline int module_unload_init(struct module *mod)
995 {
996         return 0;
997 }
998 #endif /* CONFIG_MODULE_UNLOAD */
999 
1000 static size_t module_flags_taint(struct module *mod, char *buf)
1001 {
1002         size_t l = 0;
1003 
1004         if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1005                 buf[l++] = 'P';
1006         if (mod->taints & (1 << TAINT_OOT_MODULE))
1007                 buf[l++] = 'O';
1008         if (mod->taints & (1 << TAINT_FORCED_MODULE))
1009                 buf[l++] = 'F';
1010         if (mod->taints & (1 << TAINT_CRAP))
1011                 buf[l++] = 'C';
1012         if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1013                 buf[l++] = 'E';
1014         /*
1015          * TAINT_FORCED_RMMOD: could be added.
1016          * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1017          * apply to modules.
1018          */
1019         return l;
1020 }
1021 
1022 static ssize_t show_initstate(struct module_attribute *mattr,
1023                               struct module_kobject *mk, char *buffer)
1024 {
1025         const char *state = "unknown";
1026 
1027         switch (mk->mod->state) {
1028         case MODULE_STATE_LIVE:
1029                 state = "live";
1030                 break;
1031         case MODULE_STATE_COMING:
1032                 state = "coming";
1033                 break;
1034         case MODULE_STATE_GOING:
1035                 state = "going";
1036                 break;
1037         default:
1038                 BUG();
1039         }
1040         return sprintf(buffer, "%s\n", state);
1041 }
1042 
1043 static struct module_attribute modinfo_initstate =
1044         __ATTR(initstate, 0444, show_initstate, NULL);
1045 
1046 static ssize_t store_uevent(struct module_attribute *mattr,
1047                             struct module_kobject *mk,
1048                             const char *buffer, size_t count)
1049 {
1050         enum kobject_action action;
1051 
1052         if (kobject_action_type(buffer, count, &action) == 0)
1053                 kobject_uevent(&mk->kobj, action);
1054         return count;
1055 }
1056 
1057 struct module_attribute module_uevent =
1058         __ATTR(uevent, 0200, NULL, store_uevent);
1059 
1060 static ssize_t show_coresize(struct module_attribute *mattr,
1061                              struct module_kobject *mk, char *buffer)
1062 {
1063         return sprintf(buffer, "%u\n", mk->mod->core_size);
1064 }
1065 
1066 static struct module_attribute modinfo_coresize =
1067         __ATTR(coresize, 0444, show_coresize, NULL);
1068 
1069 static ssize_t show_initsize(struct module_attribute *mattr,
1070                              struct module_kobject *mk, char *buffer)
1071 {
1072         return sprintf(buffer, "%u\n", mk->mod->init_size);
1073 }
1074 
1075 static struct module_attribute modinfo_initsize =
1076         __ATTR(initsize, 0444, show_initsize, NULL);
1077 
1078 static ssize_t show_taint(struct module_attribute *mattr,
1079                           struct module_kobject *mk, char *buffer)
1080 {
1081         size_t l;
1082 
1083         l = module_flags_taint(mk->mod, buffer);
1084         buffer[l++] = '\n';
1085         return l;
1086 }
1087 
1088 static struct module_attribute modinfo_taint =
1089         __ATTR(taint, 0444, show_taint, NULL);
1090 
1091 static struct module_attribute *modinfo_attrs[] = {
1092         &module_uevent,
1093         &modinfo_version,
1094         &modinfo_srcversion,
1095         &modinfo_initstate,
1096         &modinfo_coresize,
1097         &modinfo_initsize,
1098         &modinfo_taint,
1099 #ifdef CONFIG_MODULE_UNLOAD
1100         &modinfo_refcnt,
1101 #endif
1102         NULL,
1103 };
1104 
1105 static const char vermagic[] = VERMAGIC_STRING;
1106 
1107 static int try_to_force_load(struct module *mod, const char *reason)
1108 {
1109 #ifdef CONFIG_MODULE_FORCE_LOAD
1110         if (!test_taint(TAINT_FORCED_MODULE))
1111                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1112         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1113         return 0;
1114 #else
1115         return -ENOEXEC;
1116 #endif
1117 }
1118 
1119 #ifdef CONFIG_MODVERSIONS
1120 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1121 static unsigned long maybe_relocated(unsigned long crc,
1122                                      const struct module *crc_owner)
1123 {
1124 #ifdef ARCH_RELOCATES_KCRCTAB
1125         if (crc_owner == NULL)
1126                 return crc - (unsigned long)reloc_start;
1127 #endif
1128         return crc;
1129 }
1130 
1131 static int check_version(Elf_Shdr *sechdrs,
1132                          unsigned int versindex,
1133                          const char *symname,
1134                          struct module *mod, 
1135                          const unsigned long *crc,
1136                          const struct module *crc_owner)
1137 {
1138         unsigned int i, num_versions;
1139         struct modversion_info *versions;
1140 
1141         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1142         if (!crc)
1143                 return 1;
1144 
1145         /* No versions at all?  modprobe --force does this. */
1146         if (versindex == 0)
1147                 return try_to_force_load(mod, symname) == 0;
1148 
1149         versions = (void *) sechdrs[versindex].sh_addr;
1150         num_versions = sechdrs[versindex].sh_size
1151                 / sizeof(struct modversion_info);
1152 
1153         for (i = 0; i < num_versions; i++) {
1154                 if (strcmp(versions[i].name, symname) != 0)
1155                         continue;
1156 
1157                 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1158                         return 1;
1159                 pr_debug("Found checksum %lX vs module %lX\n",
1160                        maybe_relocated(*crc, crc_owner), versions[i].crc);
1161                 goto bad_version;
1162         }
1163 
1164         pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1165         return 0;
1166 
1167 bad_version:
1168         printk("%s: disagrees about version of symbol %s\n",
1169                mod->name, symname);
1170         return 0;
1171 }
1172 
1173 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1174                                           unsigned int versindex,
1175                                           struct module *mod)
1176 {
1177         const unsigned long *crc;
1178 
1179         /* Since this should be found in kernel (which can't be removed),
1180          * no locking is necessary. */
1181         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1182                          &crc, true, false))
1183                 BUG();
1184         return check_version(sechdrs, versindex,
1185                              VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1186                              NULL);
1187 }
1188 
1189 /* First part is kernel version, which we ignore if module has crcs. */
1190 static inline int same_magic(const char *amagic, const char *bmagic,
1191                              bool has_crcs)
1192 {
1193         if (has_crcs) {
1194                 amagic += strcspn(amagic, " ");
1195                 bmagic += strcspn(bmagic, " ");
1196         }
1197         return strcmp(amagic, bmagic) == 0;
1198 }
1199 #else
1200 static inline int check_version(Elf_Shdr *sechdrs,
1201                                 unsigned int versindex,
1202                                 const char *symname,
1203                                 struct module *mod, 
1204                                 const unsigned long *crc,
1205                                 const struct module *crc_owner)
1206 {
1207         return 1;
1208 }
1209 
1210 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1211                                           unsigned int versindex,
1212                                           struct module *mod)
1213 {
1214         return 1;
1215 }
1216 
1217 static inline int same_magic(const char *amagic, const char *bmagic,
1218                              bool has_crcs)
1219 {
1220         return strcmp(amagic, bmagic) == 0;
1221 }
1222 #endif /* CONFIG_MODVERSIONS */
1223 
1224 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1225 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1226                                                   const struct load_info *info,
1227                                                   const char *name,
1228                                                   char ownername[])
1229 {
1230         struct module *owner;
1231         const struct kernel_symbol *sym;
1232         const unsigned long *crc;
1233         int err;
1234 
1235         mutex_lock(&module_mutex);
1236         sym = find_symbol(name, &owner, &crc,
1237                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1238         if (!sym)
1239                 goto unlock;
1240 
1241         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1242                            owner)) {
1243                 sym = ERR_PTR(-EINVAL);
1244                 goto getname;
1245         }
1246 
1247         err = ref_module(mod, owner);
1248         if (err) {
1249                 sym = ERR_PTR(err);
1250                 goto getname;
1251         }
1252 
1253 getname:
1254         /* We must make copy under the lock if we failed to get ref. */
1255         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1256 unlock:
1257         mutex_unlock(&module_mutex);
1258         return sym;
1259 }
1260 
1261 static const struct kernel_symbol *
1262 resolve_symbol_wait(struct module *mod,
1263                     const struct load_info *info,
1264                     const char *name)
1265 {
1266         const struct kernel_symbol *ksym;
1267         char owner[MODULE_NAME_LEN];
1268 
1269         if (wait_event_interruptible_timeout(module_wq,
1270                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1271                         || PTR_ERR(ksym) != -EBUSY,
1272                                              30 * HZ) <= 0) {
1273                 pr_warn("%s: gave up waiting for init of module %s.\n",
1274                         mod->name, owner);
1275         }
1276         return ksym;
1277 }
1278 
1279 /*
1280  * /sys/module/foo/sections stuff
1281  * J. Corbet <corbet@lwn.net>
1282  */
1283 #ifdef CONFIG_SYSFS
1284 
1285 #ifdef CONFIG_KALLSYMS
1286 static inline bool sect_empty(const Elf_Shdr *sect)
1287 {
1288         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1289 }
1290 
1291 struct module_sect_attr
1292 {
1293         struct module_attribute mattr;
1294         char *name;
1295         unsigned long address;
1296 };
1297 
1298 struct module_sect_attrs
1299 {
1300         struct attribute_group grp;
1301         unsigned int nsections;
1302         struct module_sect_attr attrs[0];
1303 };
1304 
1305 static ssize_t module_sect_show(struct module_attribute *mattr,
1306                                 struct module_kobject *mk, char *buf)
1307 {
1308         struct module_sect_attr *sattr =
1309                 container_of(mattr, struct module_sect_attr, mattr);
1310         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1311 }
1312 
1313 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1314 {
1315         unsigned int section;
1316 
1317         for (section = 0; section < sect_attrs->nsections; section++)
1318                 kfree(sect_attrs->attrs[section].name);
1319         kfree(sect_attrs);
1320 }
1321 
1322 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1323 {
1324         unsigned int nloaded = 0, i, size[2];
1325         struct module_sect_attrs *sect_attrs;
1326         struct module_sect_attr *sattr;
1327         struct attribute **gattr;
1328 
1329         /* Count loaded sections and allocate structures */
1330         for (i = 0; i < info->hdr->e_shnum; i++)
1331                 if (!sect_empty(&info->sechdrs[i]))
1332                         nloaded++;
1333         size[0] = ALIGN(sizeof(*sect_attrs)
1334                         + nloaded * sizeof(sect_attrs->attrs[0]),
1335                         sizeof(sect_attrs->grp.attrs[0]));
1336         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1337         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1338         if (sect_attrs == NULL)
1339                 return;
1340 
1341         /* Setup section attributes. */
1342         sect_attrs->grp.name = "sections";
1343         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1344 
1345         sect_attrs->nsections = 0;
1346         sattr = &sect_attrs->attrs[0];
1347         gattr = &sect_attrs->grp.attrs[0];
1348         for (i = 0; i < info->hdr->e_shnum; i++) {
1349                 Elf_Shdr *sec = &info->sechdrs[i];
1350                 if (sect_empty(sec))
1351                         continue;
1352                 sattr->address = sec->sh_addr;
1353                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1354                                         GFP_KERNEL);
1355                 if (sattr->name == NULL)
1356                         goto out;
1357                 sect_attrs->nsections++;
1358                 sysfs_attr_init(&sattr->mattr.attr);
1359                 sattr->mattr.show = module_sect_show;
1360                 sattr->mattr.store = NULL;
1361                 sattr->mattr.attr.name = sattr->name;
1362                 sattr->mattr.attr.mode = S_IRUGO;
1363                 *(gattr++) = &(sattr++)->mattr.attr;
1364         }
1365         *gattr = NULL;
1366 
1367         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1368                 goto out;
1369 
1370         mod->sect_attrs = sect_attrs;
1371         return;
1372   out:
1373         free_sect_attrs(sect_attrs);
1374 }
1375 
1376 static void remove_sect_attrs(struct module *mod)
1377 {
1378         if (mod->sect_attrs) {
1379                 sysfs_remove_group(&mod->mkobj.kobj,
1380                                    &mod->sect_attrs->grp);
1381                 /* We are positive that no one is using any sect attrs
1382                  * at this point.  Deallocate immediately. */
1383                 free_sect_attrs(mod->sect_attrs);
1384                 mod->sect_attrs = NULL;
1385         }
1386 }
1387 
1388 /*
1389  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1390  */
1391 
1392 struct module_notes_attrs {
1393         struct kobject *dir;
1394         unsigned int notes;
1395         struct bin_attribute attrs[0];
1396 };
1397 
1398 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1399                                  struct bin_attribute *bin_attr,
1400                                  char *buf, loff_t pos, size_t count)
1401 {
1402         /*
1403          * The caller checked the pos and count against our size.
1404          */
1405         memcpy(buf, bin_attr->private + pos, count);
1406         return count;
1407 }
1408 
1409 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1410                              unsigned int i)
1411 {
1412         if (notes_attrs->dir) {
1413                 while (i-- > 0)
1414                         sysfs_remove_bin_file(notes_attrs->dir,
1415                                               &notes_attrs->attrs[i]);
1416                 kobject_put(notes_attrs->dir);
1417         }
1418         kfree(notes_attrs);
1419 }
1420 
1421 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1422 {
1423         unsigned int notes, loaded, i;
1424         struct module_notes_attrs *notes_attrs;
1425         struct bin_attribute *nattr;
1426 
1427         /* failed to create section attributes, so can't create notes */
1428         if (!mod->sect_attrs)
1429                 return;
1430 
1431         /* Count notes sections and allocate structures.  */
1432         notes = 0;
1433         for (i = 0; i < info->hdr->e_shnum; i++)
1434                 if (!sect_empty(&info->sechdrs[i]) &&
1435                     (info->sechdrs[i].sh_type == SHT_NOTE))
1436                         ++notes;
1437 
1438         if (notes == 0)
1439                 return;
1440 
1441         notes_attrs = kzalloc(sizeof(*notes_attrs)
1442                               + notes * sizeof(notes_attrs->attrs[0]),
1443                               GFP_KERNEL);
1444         if (notes_attrs == NULL)
1445                 return;
1446 
1447         notes_attrs->notes = notes;
1448         nattr = &notes_attrs->attrs[0];
1449         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1450                 if (sect_empty(&info->sechdrs[i]))
1451                         continue;
1452                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1453                         sysfs_bin_attr_init(nattr);
1454                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1455                         nattr->attr.mode = S_IRUGO;
1456                         nattr->size = info->sechdrs[i].sh_size;
1457                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1458                         nattr->read = module_notes_read;
1459                         ++nattr;
1460                 }
1461                 ++loaded;
1462         }
1463 
1464         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1465         if (!notes_attrs->dir)
1466                 goto out;
1467 
1468         for (i = 0; i < notes; ++i)
1469                 if (sysfs_create_bin_file(notes_attrs->dir,
1470                                           &notes_attrs->attrs[i]))
1471                         goto out;
1472 
1473         mod->notes_attrs = notes_attrs;
1474         return;
1475 
1476   out:
1477         free_notes_attrs(notes_attrs, i);
1478 }
1479 
1480 static void remove_notes_attrs(struct module *mod)
1481 {
1482         if (mod->notes_attrs)
1483                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1484 }
1485 
1486 #else
1487 
1488 static inline void add_sect_attrs(struct module *mod,
1489                                   const struct load_info *info)
1490 {
1491 }
1492 
1493 static inline void remove_sect_attrs(struct module *mod)
1494 {
1495 }
1496 
1497 static inline void add_notes_attrs(struct module *mod,
1498                                    const struct load_info *info)
1499 {
1500 }
1501 
1502 static inline void remove_notes_attrs(struct module *mod)
1503 {
1504 }
1505 #endif /* CONFIG_KALLSYMS */
1506 
1507 static void add_usage_links(struct module *mod)
1508 {
1509 #ifdef CONFIG_MODULE_UNLOAD
1510         struct module_use *use;
1511         int nowarn;
1512 
1513         mutex_lock(&module_mutex);
1514         list_for_each_entry(use, &mod->target_list, target_list) {
1515                 nowarn = sysfs_create_link(use->target->holders_dir,
1516                                            &mod->mkobj.kobj, mod->name);
1517         }
1518         mutex_unlock(&module_mutex);
1519 #endif
1520 }
1521 
1522 static void del_usage_links(struct module *mod)
1523 {
1524 #ifdef CONFIG_MODULE_UNLOAD
1525         struct module_use *use;
1526 
1527         mutex_lock(&module_mutex);
1528         list_for_each_entry(use, &mod->target_list, target_list)
1529                 sysfs_remove_link(use->target->holders_dir, mod->name);
1530         mutex_unlock(&module_mutex);
1531 #endif
1532 }
1533 
1534 static int module_add_modinfo_attrs(struct module *mod)
1535 {
1536         struct module_attribute *attr;
1537         struct module_attribute *temp_attr;
1538         int error = 0;
1539         int i;
1540 
1541         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1542                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1543                                         GFP_KERNEL);
1544         if (!mod->modinfo_attrs)
1545                 return -ENOMEM;
1546 
1547         temp_attr = mod->modinfo_attrs;
1548         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1549                 if (!attr->test ||
1550                     (attr->test && attr->test(mod))) {
1551                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1552                         sysfs_attr_init(&temp_attr->attr);
1553                         error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1554                         ++temp_attr;
1555                 }
1556         }
1557         return error;
1558 }
1559 
1560 static void module_remove_modinfo_attrs(struct module *mod)
1561 {
1562         struct module_attribute *attr;
1563         int i;
1564 
1565         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1566                 /* pick a field to test for end of list */
1567                 if (!attr->attr.name)
1568                         break;
1569                 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1570                 if (attr->free)
1571                         attr->free(mod);
1572         }
1573         kfree(mod->modinfo_attrs);
1574 }
1575 
1576 static void mod_kobject_put(struct module *mod)
1577 {
1578         DECLARE_COMPLETION_ONSTACK(c);
1579         mod->mkobj.kobj_completion = &c;
1580         kobject_put(&mod->mkobj.kobj);
1581         wait_for_completion(&c);
1582 }
1583 
1584 static int mod_sysfs_init(struct module *mod)
1585 {
1586         int err;
1587         struct kobject *kobj;
1588 
1589         if (!module_sysfs_initialized) {
1590                 pr_err("%s: module sysfs not initialized\n", mod->name);
1591                 err = -EINVAL;
1592                 goto out;
1593         }
1594 
1595         kobj = kset_find_obj(module_kset, mod->name);
1596         if (kobj) {
1597                 pr_err("%s: module is already loaded\n", mod->name);
1598                 kobject_put(kobj);
1599                 err = -EINVAL;
1600                 goto out;
1601         }
1602 
1603         mod->mkobj.mod = mod;
1604 
1605         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1606         mod->mkobj.kobj.kset = module_kset;
1607         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1608                                    "%s", mod->name);
1609         if (err)
1610                 mod_kobject_put(mod);
1611 
1612         /* delay uevent until full sysfs population */
1613 out:
1614         return err;
1615 }
1616 
1617 static int mod_sysfs_setup(struct module *mod,
1618                            const struct load_info *info,
1619                            struct kernel_param *kparam,
1620                            unsigned int num_params)
1621 {
1622         int err;
1623 
1624         err = mod_sysfs_init(mod);
1625         if (err)
1626                 goto out;
1627 
1628         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1629         if (!mod->holders_dir) {
1630                 err = -ENOMEM;
1631                 goto out_unreg;
1632         }
1633 
1634         err = module_param_sysfs_setup(mod, kparam, num_params);
1635         if (err)
1636                 goto out_unreg_holders;
1637 
1638         err = module_add_modinfo_attrs(mod);
1639         if (err)
1640                 goto out_unreg_param;
1641 
1642         add_usage_links(mod);
1643         add_sect_attrs(mod, info);
1644         add_notes_attrs(mod, info);
1645 
1646         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1647         return 0;
1648 
1649 out_unreg_param:
1650         module_param_sysfs_remove(mod);
1651 out_unreg_holders:
1652         kobject_put(mod->holders_dir);
1653 out_unreg:
1654         mod_kobject_put(mod);
1655 out:
1656         return err;
1657 }
1658 
1659 static void mod_sysfs_fini(struct module *mod)
1660 {
1661         remove_notes_attrs(mod);
1662         remove_sect_attrs(mod);
1663         mod_kobject_put(mod);
1664 }
1665 
1666 #else /* !CONFIG_SYSFS */
1667 
1668 static int mod_sysfs_setup(struct module *mod,
1669                            const struct load_info *info,
1670                            struct kernel_param *kparam,
1671                            unsigned int num_params)
1672 {
1673         return 0;
1674 }
1675 
1676 static void mod_sysfs_fini(struct module *mod)
1677 {
1678 }
1679 
1680 static void module_remove_modinfo_attrs(struct module *mod)
1681 {
1682 }
1683 
1684 static void del_usage_links(struct module *mod)
1685 {
1686 }
1687 
1688 #endif /* CONFIG_SYSFS */
1689 
1690 static void mod_sysfs_teardown(struct module *mod)
1691 {
1692         del_usage_links(mod);
1693         module_remove_modinfo_attrs(mod);
1694         module_param_sysfs_remove(mod);
1695         kobject_put(mod->mkobj.drivers_dir);
1696         kobject_put(mod->holders_dir);
1697         mod_sysfs_fini(mod);
1698 }
1699 
1700 /*
1701  * unlink the module with the whole machine is stopped with interrupts off
1702  * - this defends against kallsyms not taking locks
1703  */
1704 static int __unlink_module(void *_mod)
1705 {
1706         struct module *mod = _mod;
1707         list_del(&mod->list);
1708         module_bug_cleanup(mod);
1709         return 0;
1710 }
1711 
1712 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1713 /*
1714  * LKM RO/NX protection: protect module's text/ro-data
1715  * from modification and any data from execution.
1716  */
1717 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1718 {
1719         unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1720         unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1721 
1722         if (end_pfn > begin_pfn)
1723                 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1724 }
1725 
1726 static void set_section_ro_nx(void *base,
1727                         unsigned long text_size,
1728                         unsigned long ro_size,
1729                         unsigned long total_size)
1730 {
1731         /* begin and end PFNs of the current subsection */
1732         unsigned long begin_pfn;
1733         unsigned long end_pfn;
1734 
1735         /*
1736          * Set RO for module text and RO-data:
1737          * - Always protect first page.
1738          * - Do not protect last partial page.
1739          */
1740         if (ro_size > 0)
1741                 set_page_attributes(base, base + ro_size, set_memory_ro);
1742 
1743         /*
1744          * Set NX permissions for module data:
1745          * - Do not protect first partial page.
1746          * - Always protect last page.
1747          */
1748         if (total_size > text_size) {
1749                 begin_pfn = PFN_UP((unsigned long)base + text_size);
1750                 end_pfn = PFN_UP((unsigned long)base + total_size);
1751                 if (end_pfn > begin_pfn)
1752                         set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1753         }
1754 }
1755 
1756 static void unset_module_core_ro_nx(struct module *mod)
1757 {
1758         set_page_attributes(mod->module_core + mod->core_text_size,
1759                 mod->module_core + mod->core_size,
1760                 set_memory_x);
1761         set_page_attributes(mod->module_core,
1762                 mod->module_core + mod->core_ro_size,
1763                 set_memory_rw);
1764 }
1765 
1766 static void unset_module_init_ro_nx(struct module *mod)
1767 {
1768         set_page_attributes(mod->module_init + mod->init_text_size,
1769                 mod->module_init + mod->init_size,
1770                 set_memory_x);
1771         set_page_attributes(mod->module_init,
1772                 mod->module_init + mod->init_ro_size,
1773                 set_memory_rw);
1774 }
1775 
1776 /* Iterate through all modules and set each module's text as RW */
1777 void set_all_modules_text_rw(void)
1778 {
1779         struct module *mod;
1780 
1781         mutex_lock(&module_mutex);
1782         list_for_each_entry_rcu(mod, &modules, list) {
1783                 if (mod->state == MODULE_STATE_UNFORMED)
1784                         continue;
1785                 if ((mod->module_core) && (mod->core_text_size)) {
1786                         set_page_attributes(mod->module_core,
1787                                                 mod->module_core + mod->core_text_size,
1788                                                 set_memory_rw);
1789                 }
1790                 if ((mod->module_init) && (mod->init_text_size)) {
1791                         set_page_attributes(mod->module_init,
1792                                                 mod->module_init + mod->init_text_size,
1793                                                 set_memory_rw);
1794                 }
1795         }
1796         mutex_unlock(&module_mutex);
1797 }
1798 
1799 /* Iterate through all modules and set each module's text as RO */
1800 void set_all_modules_text_ro(void)
1801 {
1802         struct module *mod;
1803 
1804         mutex_lock(&module_mutex);
1805         list_for_each_entry_rcu(mod, &modules, list) {
1806                 if (mod->state == MODULE_STATE_UNFORMED)
1807                         continue;
1808                 if ((mod->module_core) && (mod->core_text_size)) {
1809                         set_page_attributes(mod->module_core,
1810                                                 mod->module_core + mod->core_text_size,
1811                                                 set_memory_ro);
1812                 }
1813                 if ((mod->module_init) && (mod->init_text_size)) {
1814                         set_page_attributes(mod->module_init,
1815                                                 mod->module_init + mod->init_text_size,
1816                                                 set_memory_ro);
1817                 }
1818         }
1819         mutex_unlock(&module_mutex);
1820 }
1821 #else
1822 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1823 static void unset_module_core_ro_nx(struct module *mod) { }
1824 static void unset_module_init_ro_nx(struct module *mod) { }
1825 #endif
1826 
1827 void __weak module_free(struct module *mod, void *module_region)
1828 {
1829         vfree(module_region);
1830 }
1831 
1832 void __weak module_arch_cleanup(struct module *mod)
1833 {
1834 }
1835 
1836 /* Free a module, remove from lists, etc. */
1837 static void free_module(struct module *mod)
1838 {
1839         trace_module_free(mod);
1840 
1841         mod_sysfs_teardown(mod);
1842 
1843         /* We leave it in list to prevent duplicate loads, but make sure
1844          * that noone uses it while it's being deconstructed. */
1845         mutex_lock(&module_mutex);
1846         mod->state = MODULE_STATE_UNFORMED;
1847         mutex_unlock(&module_mutex);
1848 
1849         /* Remove dynamic debug info */
1850         ddebug_remove_module(mod->name);
1851 
1852         /* Arch-specific cleanup. */
1853         module_arch_cleanup(mod);
1854 
1855         /* Module unload stuff */
1856         module_unload_free(mod);
1857 
1858         /* Free any allocated parameters. */
1859         destroy_params(mod->kp, mod->num_kp);
1860 
1861         /* Now we can delete it from the lists */
1862         mutex_lock(&module_mutex);
1863         stop_machine(__unlink_module, mod, NULL);
1864         mutex_unlock(&module_mutex);
1865 
1866         /* This may be NULL, but that's OK */
1867         unset_module_init_ro_nx(mod);
1868         module_free(mod, mod->module_init);
1869         kfree(mod->args);
1870         percpu_modfree(mod);
1871 
1872         /* Free lock-classes: */
1873         lockdep_free_key_range(mod->module_core, mod->core_size);
1874 
1875         /* Finally, free the core (containing the module structure) */
1876         unset_module_core_ro_nx(mod);
1877         module_free(mod, mod->module_core);
1878 
1879 #ifdef CONFIG_MPU
1880         update_protections(current->mm);
1881 #endif
1882 }
1883 
1884 void *__symbol_get(const char *symbol)
1885 {
1886         struct module *owner;
1887         const struct kernel_symbol *sym;
1888 
1889         preempt_disable();
1890         sym = find_symbol(symbol, &owner, NULL, true, true);
1891         if (sym && strong_try_module_get(owner))
1892                 sym = NULL;
1893         preempt_enable();
1894 
1895         return sym ? (void *)sym->value : NULL;
1896 }
1897 EXPORT_SYMBOL_GPL(__symbol_get);
1898 
1899 /*
1900  * Ensure that an exported symbol [global namespace] does not already exist
1901  * in the kernel or in some other module's exported symbol table.
1902  *
1903  * You must hold the module_mutex.
1904  */
1905 static int verify_export_symbols(struct module *mod)
1906 {
1907         unsigned int i;
1908         struct module *owner;
1909         const struct kernel_symbol *s;
1910         struct {
1911                 const struct kernel_symbol *sym;
1912                 unsigned int num;
1913         } arr[] = {
1914                 { mod->syms, mod->num_syms },
1915                 { mod->gpl_syms, mod->num_gpl_syms },
1916                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1917 #ifdef CONFIG_UNUSED_SYMBOLS
1918                 { mod->unused_syms, mod->num_unused_syms },
1919                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1920 #endif
1921         };
1922 
1923         for (i = 0; i < ARRAY_SIZE(arr); i++) {
1924                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1925                         if (find_symbol(s->name, &owner, NULL, true, false)) {
1926                                 pr_err("%s: exports duplicate symbol %s"
1927                                        " (owned by %s)\n",
1928                                        mod->name, s->name, module_name(owner));
1929                                 return -ENOEXEC;
1930                         }
1931                 }
1932         }
1933         return 0;
1934 }
1935 
1936 /* Change all symbols so that st_value encodes the pointer directly. */
1937 static int simplify_symbols(struct module *mod, const struct load_info *info)
1938 {
1939         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1940         Elf_Sym *sym = (void *)symsec->sh_addr;
1941         unsigned long secbase;
1942         unsigned int i;
1943         int ret = 0;
1944         const struct kernel_symbol *ksym;
1945 
1946         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1947                 const char *name = info->strtab + sym[i].st_name;
1948 
1949                 switch (sym[i].st_shndx) {
1950                 case SHN_COMMON:
1951                         /* Ignore common symbols */
1952                         if (!strncmp(name, "__gnu_lto", 9))
1953                                 break;
1954 
1955                         /* We compiled with -fno-common.  These are not
1956                            supposed to happen.  */
1957                         pr_debug("Common symbol: %s\n", name);
1958                         printk("%s: please compile with -fno-common\n",
1959                                mod->name);
1960                         ret = -ENOEXEC;
1961                         break;
1962 
1963                 case SHN_ABS:
1964                         /* Don't need to do anything */
1965                         pr_debug("Absolute symbol: 0x%08lx\n",
1966                                (long)sym[i].st_value);
1967                         break;
1968 
1969                 case SHN_UNDEF:
1970                         ksym = resolve_symbol_wait(mod, info, name);
1971                         /* Ok if resolved.  */
1972                         if (ksym && !IS_ERR(ksym)) {
1973                                 sym[i].st_value = ksym->value;
1974                                 break;
1975                         }
1976 
1977                         /* Ok if weak.  */
1978                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1979                                 break;
1980 
1981                         pr_warn("%s: Unknown symbol %s (err %li)\n",
1982                                 mod->name, name, PTR_ERR(ksym));
1983                         ret = PTR_ERR(ksym) ?: -ENOENT;
1984                         break;
1985 
1986                 default:
1987                         /* Divert to percpu allocation if a percpu var. */
1988                         if (sym[i].st_shndx == info->index.pcpu)
1989                                 secbase = (unsigned long)mod_percpu(mod);
1990                         else
1991                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1992                         sym[i].st_value += secbase;
1993                         break;
1994                 }
1995         }
1996 
1997         return ret;
1998 }
1999 
2000 static int apply_relocations(struct module *mod, const struct load_info *info)
2001 {
2002         unsigned int i;
2003         int err = 0;
2004 
2005         /* Now do relocations. */
2006         for (i = 1; i < info->hdr->e_shnum; i++) {
2007                 unsigned int infosec = info->sechdrs[i].sh_info;
2008 
2009                 /* Not a valid relocation section? */
2010                 if (infosec >= info->hdr->e_shnum)
2011                         continue;
2012 
2013                 /* Don't bother with non-allocated sections */
2014                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2015                         continue;
2016 
2017                 if (info->sechdrs[i].sh_type == SHT_REL)
2018                         err = apply_relocate(info->sechdrs, info->strtab,
2019                                              info->index.sym, i, mod);
2020                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2021                         err = apply_relocate_add(info->sechdrs, info->strtab,
2022                                                  info->index.sym, i, mod);
2023                 if (err < 0)
2024                         break;
2025         }
2026         return err;
2027 }
2028 
2029 /* Additional bytes needed by arch in front of individual sections */
2030 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2031                                              unsigned int section)
2032 {
2033         /* default implementation just returns zero */
2034         return 0;
2035 }
2036 
2037 /* Update size with this section: return offset. */
2038 static long get_offset(struct module *mod, unsigned int *size,
2039                        Elf_Shdr *sechdr, unsigned int section)
2040 {
2041         long ret;
2042 
2043         *size += arch_mod_section_prepend(mod, section);
2044         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2045         *size = ret + sechdr->sh_size;
2046         return ret;
2047 }
2048 
2049 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2050    might -- code, read-only data, read-write data, small data.  Tally
2051    sizes, and place the offsets into sh_entsize fields: high bit means it
2052    belongs in init. */
2053 static void layout_sections(struct module *mod, struct load_info *info)
2054 {
2055         static unsigned long const masks[][2] = {
2056                 /* NOTE: all executable code must be the first section
2057                  * in this array; otherwise modify the text_size
2058                  * finder in the two loops below */
2059                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2060                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2061                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2062                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2063         };
2064         unsigned int m, i;
2065 
2066         for (i = 0; i < info->hdr->e_shnum; i++)
2067                 info->sechdrs[i].sh_entsize = ~0UL;
2068 
2069         pr_debug("Core section allocation order:\n");
2070         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2071                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2072                         Elf_Shdr *s = &info->sechdrs[i];
2073                         const char *sname = info->secstrings + s->sh_name;
2074 
2075                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2076                             || (s->sh_flags & masks[m][1])
2077                             || s->sh_entsize != ~0UL
2078                             || strstarts(sname, ".init"))
2079                                 continue;
2080                         s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2081                         pr_debug("\t%s\n", sname);
2082                 }
2083                 switch (m) {
2084                 case 0: /* executable */
2085                         mod->core_size = debug_align(mod->core_size);
2086                         mod->core_text_size = mod->core_size;
2087                         break;
2088                 case 1: /* RO: text and ro-data */
2089                         mod->core_size = debug_align(mod->core_size);
2090                         mod->core_ro_size = mod->core_size;
2091                         break;
2092                 case 3: /* whole core */
2093                         mod->core_size = debug_align(mod->core_size);
2094                         break;
2095                 }
2096         }
2097 
2098         pr_debug("Init section allocation order:\n");
2099         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2100                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2101                         Elf_Shdr *s = &info->sechdrs[i];
2102                         const char *sname = info->secstrings + s->sh_name;
2103 
2104                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2105                             || (s->sh_flags & masks[m][1])
2106                             || s->sh_entsize != ~0UL
2107                             || !strstarts(sname, ".init"))
2108                                 continue;
2109                         s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2110                                          | INIT_OFFSET_MASK);
2111                         pr_debug("\t%s\n", sname);
2112                 }
2113                 switch (m) {
2114                 case 0: /* executable */
2115                         mod->init_size = debug_align(mod->init_size);
2116                         mod->init_text_size = mod->init_size;
2117                         break;
2118                 case 1: /* RO: text and ro-data */
2119                         mod->init_size = debug_align(mod->init_size);
2120                         mod->init_ro_size = mod->init_size;
2121                         break;
2122                 case 3: /* whole init */
2123                         mod->init_size = debug_align(mod->init_size);
2124                         break;
2125                 }
2126         }
2127 }
2128 
2129 static void set_license(struct module *mod, const char *license)
2130 {
2131         if (!license)
2132                 license = "unspecified";
2133 
2134         if (!license_is_gpl_compatible(license)) {
2135                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2136                         pr_warn("%s: module license '%s' taints kernel.\n",
2137                                 mod->name, license);
2138                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2139                                  LOCKDEP_NOW_UNRELIABLE);
2140         }
2141 }
2142 
2143 /* Parse tag=value strings from .modinfo section */
2144 static char *next_string(char *string, unsigned long *secsize)
2145 {
2146         /* Skip non-zero chars */
2147         while (string[0]) {
2148                 string++;
2149                 if ((*secsize)-- <= 1)
2150                         return NULL;
2151         }
2152 
2153         /* Skip any zero padding. */
2154         while (!string[0]) {
2155                 string++;
2156                 if ((*secsize)-- <= 1)
2157                         return NULL;
2158         }
2159         return string;
2160 }
2161 
2162 static char *get_modinfo(struct load_info *info, const char *tag)
2163 {
2164         char *p;
2165         unsigned int taglen = strlen(tag);
2166         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2167         unsigned long size = infosec->sh_size;
2168 
2169         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2170                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2171                         return p + taglen + 1;
2172         }
2173         return NULL;
2174 }
2175 
2176 static void setup_modinfo(struct module *mod, struct load_info *info)
2177 {
2178         struct module_attribute *attr;
2179         int i;
2180 
2181         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2182                 if (attr->setup)
2183                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2184         }
2185 }
2186 
2187 static void free_modinfo(struct module *mod)
2188 {
2189         struct module_attribute *attr;
2190         int i;
2191 
2192         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2193                 if (attr->free)
2194                         attr->free(mod);
2195         }
2196 }
2197 
2198 #ifdef CONFIG_KALLSYMS
2199 
2200 /* lookup symbol in given range of kernel_symbols */
2201 static const struct kernel_symbol *lookup_symbol(const char *name,
2202         const struct kernel_symbol *start,
2203         const struct kernel_symbol *stop)
2204 {
2205         return bsearch(name, start, stop - start,
2206                         sizeof(struct kernel_symbol), cmp_name);
2207 }
2208 
2209 static int is_exported(const char *name, unsigned long value,
2210                        const struct module *mod)
2211 {
2212         const struct kernel_symbol *ks;
2213         if (!mod)
2214                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2215         else
2216                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2217         return ks != NULL && ks->value == value;
2218 }
2219 
2220 /* As per nm */
2221 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2222 {
2223         const Elf_Shdr *sechdrs = info->sechdrs;
2224 
2225         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2226                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2227                         return 'v';
2228                 else
2229                         return 'w';
2230         }
2231         if (sym->st_shndx == SHN_UNDEF)
2232                 return 'U';
2233         if (sym->st_shndx == SHN_ABS)
2234                 return 'a';
2235         if (sym->st_shndx >= SHN_LORESERVE)
2236                 return '?';
2237         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2238                 return 't';
2239         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2240             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2241                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2242                         return 'r';
2243                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2244                         return 'g';
2245                 else
2246                         return 'd';
2247         }
2248         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2249                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2250                         return 's';
2251                 else
2252                         return 'b';
2253         }
2254         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2255                       ".debug")) {
2256                 return 'n';
2257         }
2258         return '?';
2259 }
2260 
2261 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2262                            unsigned int shnum)
2263 {
2264         const Elf_Shdr *sec;
2265 
2266         if (src->st_shndx == SHN_UNDEF
2267             || src->st_shndx >= shnum
2268             || !src->st_name)
2269                 return false;
2270 
2271         sec = sechdrs + src->st_shndx;
2272         if (!(sec->sh_flags & SHF_ALLOC)
2273 #ifndef CONFIG_KALLSYMS_ALL
2274             || !(sec->sh_flags & SHF_EXECINSTR)
2275 #endif
2276             || (sec->sh_entsize & INIT_OFFSET_MASK))
2277                 return false;
2278 
2279         return true;
2280 }
2281 
2282 /*
2283  * We only allocate and copy the strings needed by the parts of symtab
2284  * we keep.  This is simple, but has the effect of making multiple
2285  * copies of duplicates.  We could be more sophisticated, see
2286  * linux-kernel thread starting with
2287  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2288  */
2289 static void layout_symtab(struct module *mod, struct load_info *info)
2290 {
2291         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2292         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2293         const Elf_Sym *src;
2294         unsigned int i, nsrc, ndst, strtab_size = 0;
2295 
2296         /* Put symbol section at end of init part of module. */
2297         symsect->sh_flags |= SHF_ALLOC;
2298         symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2299                                          info->index.sym) | INIT_OFFSET_MASK;
2300         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2301 
2302         src = (void *)info->hdr + symsect->sh_offset;
2303         nsrc = symsect->sh_size / sizeof(*src);
2304 
2305         /* Compute total space required for the core symbols' strtab. */
2306         for (ndst = i = 0; i < nsrc; i++) {
2307                 if (i == 0 ||
2308                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2309                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2310                         ndst++;
2311                 }
2312         }
2313 
2314         /* Append room for core symbols at end of core part. */
2315         info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2316         info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2317         mod->core_size += strtab_size;
2318 
2319         /* Put string table section at end of init part of module. */
2320         strsect->sh_flags |= SHF_ALLOC;
2321         strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2322                                          info->index.str) | INIT_OFFSET_MASK;
2323         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2324 }
2325 
2326 static void add_kallsyms(struct module *mod, const struct load_info *info)
2327 {
2328         unsigned int i, ndst;
2329         const Elf_Sym *src;
2330         Elf_Sym *dst;
2331         char *s;
2332         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2333 
2334         mod->symtab = (void *)symsec->sh_addr;
2335         mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2336         /* Make sure we get permanent strtab: don't use info->strtab. */
2337         mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2338 
2339         /* Set types up while we still have access to sections. */
2340         for (i = 0; i < mod->num_symtab; i++)
2341                 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2342 
2343         mod->core_symtab = dst = mod->module_core + info->symoffs;
2344         mod->core_strtab = s = mod->module_core + info->stroffs;
2345         src = mod->symtab;
2346         for (ndst = i = 0; i < mod->num_symtab; i++) {
2347                 if (i == 0 ||
2348                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2349                         dst[ndst] = src[i];
2350                         dst[ndst++].st_name = s - mod->core_strtab;
2351                         s += strlcpy(s, &mod->strtab[src[i].st_name],
2352                                      KSYM_NAME_LEN) + 1;
2353                 }
2354         }
2355         mod->core_num_syms = ndst;
2356 }
2357 #else
2358 static inline void layout_symtab(struct module *mod, struct load_info *info)
2359 {
2360 }
2361 
2362 static void add_kallsyms(struct module *mod, const struct load_info *info)
2363 {
2364 }
2365 #endif /* CONFIG_KALLSYMS */
2366 
2367 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2368 {
2369         if (!debug)
2370                 return;
2371 #ifdef CONFIG_DYNAMIC_DEBUG
2372         if (ddebug_add_module(debug, num, debug->modname))
2373                 pr_err("dynamic debug error adding module: %s\n",
2374                         debug->modname);
2375 #endif
2376 }
2377 
2378 static void dynamic_debug_remove(struct _ddebug *debug)
2379 {
2380         if (debug)
2381                 ddebug_remove_module(debug->modname);
2382 }
2383 
2384 void * __weak module_alloc(unsigned long size)
2385 {
2386         return vmalloc_exec(size);
2387 }
2388 
2389 static void *module_alloc_update_bounds(unsigned long size)
2390 {
2391         void *ret = module_alloc(size);
2392 
2393         if (ret) {
2394                 mutex_lock(&module_mutex);
2395                 /* Update module bounds. */
2396                 if ((unsigned long)ret < module_addr_min)
2397                         module_addr_min = (unsigned long)ret;
2398                 if ((unsigned long)ret + size > module_addr_max)
2399                         module_addr_max = (unsigned long)ret + size;
2400                 mutex_unlock(&module_mutex);
2401         }
2402         return ret;
2403 }
2404 
2405 #ifdef CONFIG_DEBUG_KMEMLEAK
2406 static void kmemleak_load_module(const struct module *mod,
2407                                  const struct load_info *info)
2408 {
2409         unsigned int i;
2410 
2411         /* only scan the sections containing data */
2412         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2413 
2414         for (i = 1; i < info->hdr->e_shnum; i++) {
2415                 /* Scan all writable sections that's not executable */
2416                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2417                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2418                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2419                         continue;
2420 
2421                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2422                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2423         }
2424 }
2425 #else
2426 static inline void kmemleak_load_module(const struct module *mod,
2427                                         const struct load_info *info)
2428 {
2429 }
2430 #endif
2431 
2432 #ifdef CONFIG_MODULE_SIG
2433 static int module_sig_check(struct load_info *info)
2434 {
2435         int err = -ENOKEY;
2436         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2437         const void *mod = info->hdr;
2438 
2439         if (info->len > markerlen &&
2440             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2441                 /* We truncate the module to discard the signature */
2442                 info->len -= markerlen;
2443                 err = mod_verify_sig(mod, &info->len);
2444         }
2445 
2446         if (!err) {
2447                 info->sig_ok = true;
2448                 return 0;
2449         }
2450 
2451         /* Not having a signature is only an error if we're strict. */
2452         if (err == -ENOKEY && !sig_enforce)
2453                 err = 0;
2454 
2455         return err;
2456 }
2457 #else /* !CONFIG_MODULE_SIG */
2458 static int module_sig_check(struct load_info *info)
2459 {
2460         return 0;
2461 }
2462 #endif /* !CONFIG_MODULE_SIG */
2463 
2464 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2465 static int elf_header_check(struct load_info *info)
2466 {
2467         if (info->len < sizeof(*(info->hdr)))
2468                 return -ENOEXEC;
2469 
2470         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2471             || info->hdr->e_type != ET_REL
2472             || !elf_check_arch(info->hdr)
2473             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2474                 return -ENOEXEC;
2475 
2476         if (info->hdr->e_shoff >= info->len
2477             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2478                 info->len - info->hdr->e_shoff))
2479                 return -ENOEXEC;
2480 
2481         return 0;
2482 }
2483 
2484 /* Sets info->hdr and info->len. */
2485 static int copy_module_from_user(const void __user *umod, unsigned long len,
2486                                   struct load_info *info)
2487 {
2488         int err;
2489 
2490         info->len = len;
2491         if (info->len < sizeof(*(info->hdr)))
2492                 return -ENOEXEC;
2493 
2494         err = security_kernel_module_from_file(NULL);
2495         if (err)
2496                 return err;
2497 
2498         /* Suck in entire file: we'll want most of it. */
2499         info->hdr = vmalloc(info->len);
2500         if (!info->hdr)
2501                 return -ENOMEM;
2502 
2503         if (copy_from_user(info->hdr, umod, info->len) != 0) {
2504                 vfree(info->hdr);
2505                 return -EFAULT;
2506         }
2507 
2508         return 0;
2509 }
2510 
2511 /* Sets info->hdr and info->len. */
2512 static int copy_module_from_fd(int fd, struct load_info *info)
2513 {
2514         struct fd f = fdget(fd);
2515         int err;
2516         struct kstat stat;
2517         loff_t pos;
2518         ssize_t bytes = 0;
2519 
2520         if (!f.file)
2521                 return -ENOEXEC;
2522 
2523         err = security_kernel_module_from_file(f.file);
2524         if (err)
2525                 goto out;
2526 
2527         err = vfs_getattr(&f.file->f_path, &stat);
2528         if (err)
2529                 goto out;
2530 
2531         if (stat.size > INT_MAX) {
2532                 err = -EFBIG;
2533                 goto out;
2534         }
2535 
2536         /* Don't hand 0 to vmalloc, it whines. */
2537         if (stat.size == 0) {
2538                 err = -EINVAL;
2539                 goto out;
2540         }
2541 
2542         info->hdr = vmalloc(stat.size);
2543         if (!info->hdr) {
2544                 err = -ENOMEM;
2545                 goto out;
2546         }
2547 
2548         pos = 0;
2549         while (pos < stat.size) {
2550                 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2551                                     stat.size - pos);
2552                 if (bytes < 0) {
2553                         vfree(info->hdr);
2554                         err = bytes;
2555                         goto out;
2556                 }
2557                 if (bytes == 0)
2558                         break;
2559                 pos += bytes;
2560         }
2561         info->len = pos;
2562 
2563 out:
2564         fdput(f);
2565         return err;
2566 }
2567 
2568 static void free_copy(struct load_info *info)
2569 {
2570         vfree(info->hdr);
2571 }
2572 
2573 static int rewrite_section_headers(struct load_info *info, int flags)
2574 {
2575         unsigned int i;
2576 
2577         /* This should always be true, but let's be sure. */
2578         info->sechdrs[0].sh_addr = 0;
2579 
2580         for (i = 1; i < info->hdr->e_shnum; i++) {
2581                 Elf_Shdr *shdr = &info->sechdrs[i];
2582                 if (shdr->sh_type != SHT_NOBITS
2583                     && info->len < shdr->sh_offset + shdr->sh_size) {
2584                         pr_err("Module len %lu truncated\n", info->len);
2585                         return -ENOEXEC;
2586                 }
2587 
2588                 /* Mark all sections sh_addr with their address in the
2589                    temporary image. */
2590                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2591 
2592 #ifndef CONFIG_MODULE_UNLOAD
2593                 /* Don't load .exit sections */
2594                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2595                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2596 #endif
2597         }
2598 
2599         /* Track but don't keep modinfo and version sections. */
2600         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2601                 info->index.vers = 0; /* Pretend no __versions section! */
2602         else
2603                 info->index.vers = find_sec(info, "__versions");
2604         info->index.info = find_sec(info, ".modinfo");
2605         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2606         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2607         return 0;
2608 }
2609 
2610 /*
2611  * Set up our basic convenience variables (pointers to section headers,
2612  * search for module section index etc), and do some basic section
2613  * verification.
2614  *
2615  * Return the temporary module pointer (we'll replace it with the final
2616  * one when we move the module sections around).
2617  */
2618 static struct module *setup_load_info(struct load_info *info, int flags)
2619 {
2620         unsigned int i;
2621         int err;
2622         struct module *mod;
2623 
2624         /* Set up the convenience variables */
2625         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2626         info->secstrings = (void *)info->hdr
2627                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2628 
2629         err = rewrite_section_headers(info, flags);
2630         if (err)
2631                 return ERR_PTR(err);
2632 
2633         /* Find internal symbols and strings. */
2634         for (i = 1; i < info->hdr->e_shnum; i++) {
2635                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2636                         info->index.sym = i;
2637                         info->index.str = info->sechdrs[i].sh_link;
2638                         info->strtab = (char *)info->hdr
2639                                 + info->sechdrs[info->index.str].sh_offset;
2640                         break;
2641                 }
2642         }
2643 
2644         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2645         if (!info->index.mod) {
2646                 pr_warn("No module found in object\n");
2647                 return ERR_PTR(-ENOEXEC);
2648         }
2649         /* This is temporary: point mod into copy of data. */
2650         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2651 
2652         if (info->index.sym == 0) {
2653                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2654                 return ERR_PTR(-ENOEXEC);
2655         }
2656 
2657         info->index.pcpu = find_pcpusec(info);
2658 
2659         /* Check module struct version now, before we try to use module. */
2660         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2661                 return ERR_PTR(-ENOEXEC);
2662 
2663         return mod;
2664 }
2665 
2666 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2667 {
2668         const char *modmagic = get_modinfo(info, "vermagic");
2669         int err;
2670 
2671         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2672                 modmagic = NULL;
2673 
2674         /* This is allowed: modprobe --force will invalidate it. */
2675         if (!modmagic) {
2676                 err = try_to_force_load(mod, "bad vermagic");
2677                 if (err)
2678                         return err;
2679         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2680                 pr_err("%s: version magic '%s' should be '%s'\n",
2681                        mod->name, modmagic, vermagic);
2682                 return -ENOEXEC;
2683         }
2684 
2685         if (!get_modinfo(info, "intree"))
2686                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2687 
2688         if (get_modinfo(info, "staging")) {
2689                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2690                 pr_warn("%s: module is from the staging directory, the quality "
2691                         "is unknown, you have been warned.\n", mod->name);
2692         }
2693 
2694         /* Set up license info based on the info section */
2695         set_license(mod, get_modinfo(info, "license"));
2696 
2697         return 0;
2698 }
2699 
2700 static int find_module_sections(struct module *mod, struct load_info *info)
2701 {
2702         mod->kp = section_objs(info, "__param",
2703                                sizeof(*mod->kp), &mod->num_kp);
2704         mod->syms = section_objs(info, "__ksymtab",
2705                                  sizeof(*mod->syms), &mod->num_syms);
2706         mod->crcs = section_addr(info, "__kcrctab");
2707         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2708                                      sizeof(*mod->gpl_syms),
2709                                      &mod->num_gpl_syms);
2710         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2711         mod->gpl_future_syms = section_objs(info,
2712                                             "__ksymtab_gpl_future",
2713                                             sizeof(*mod->gpl_future_syms),
2714                                             &mod->num_gpl_future_syms);
2715         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2716 
2717 #ifdef CONFIG_UNUSED_SYMBOLS
2718         mod->unused_syms = section_objs(info, "__ksymtab_unused",
2719                                         sizeof(*mod->unused_syms),
2720                                         &mod->num_unused_syms);
2721         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2722         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2723                                             sizeof(*mod->unused_gpl_syms),
2724                                             &mod->num_unused_gpl_syms);
2725         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2726 #endif
2727 #ifdef CONFIG_CONSTRUCTORS
2728         mod->ctors = section_objs(info, ".ctors",
2729                                   sizeof(*mod->ctors), &mod->num_ctors);
2730         if (!mod->ctors)
2731                 mod->ctors = section_objs(info, ".init_array",
2732                                 sizeof(*mod->ctors), &mod->num_ctors);
2733         else if (find_sec(info, ".init_array")) {
2734                 /*
2735                  * This shouldn't happen with same compiler and binutils
2736                  * building all parts of the module.
2737                  */
2738                 printk(KERN_WARNING "%s: has both .ctors and .init_array.\n",
2739                        mod->name);
2740                 return -EINVAL;
2741         }
2742 #endif
2743 
2744 #ifdef CONFIG_TRACEPOINTS
2745         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2746                                              sizeof(*mod->tracepoints_ptrs),
2747                                              &mod->num_tracepoints);
2748 #endif
2749 #ifdef HAVE_JUMP_LABEL
2750         mod->jump_entries = section_objs(info, "__jump_table",
2751                                         sizeof(*mod->jump_entries),
2752                                         &mod->num_jump_entries);
2753 #endif
2754 #ifdef CONFIG_EVENT_TRACING
2755         mod->trace_events = section_objs(info, "_ftrace_events",
2756                                          sizeof(*mod->trace_events),
2757                                          &mod->num_trace_events);
2758 #endif
2759 #ifdef CONFIG_TRACING
2760         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2761                                          sizeof(*mod->trace_bprintk_fmt_start),
2762                                          &mod->num_trace_bprintk_fmt);
2763 #endif
2764 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2765         /* sechdrs[0].sh_size is always zero */
2766         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2767                                              sizeof(*mod->ftrace_callsites),
2768                                              &mod->num_ftrace_callsites);
2769 #endif
2770 
2771         mod->extable = section_objs(info, "__ex_table",
2772                                     sizeof(*mod->extable), &mod->num_exentries);
2773 
2774         if (section_addr(info, "__obsparm"))
2775                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2776 
2777         info->debug = section_objs(info, "__verbose",
2778                                    sizeof(*info->debug), &info->num_debug);
2779 
2780         return 0;
2781 }
2782 
2783 static int move_module(struct module *mod, struct load_info *info)
2784 {
2785         int i;
2786         void *ptr;
2787 
2788         /* Do the allocs. */
2789         ptr = module_alloc_update_bounds(mod->core_size);
2790         /*
2791          * The pointer to this block is stored in the module structure
2792          * which is inside the block. Just mark it as not being a
2793          * leak.
2794          */
2795         kmemleak_not_leak(ptr);
2796         if (!ptr)
2797                 return -ENOMEM;
2798 
2799         memset(ptr, 0, mod->core_size);
2800         mod->module_core = ptr;
2801 
2802         if (mod->init_size) {
2803                 ptr = module_alloc_update_bounds(mod->init_size);
2804                 /*
2805                  * The pointer to this block is stored in the module structure
2806                  * which is inside the block. This block doesn't need to be
2807                  * scanned as it contains data and code that will be freed
2808                  * after the module is initialized.
2809                  */
2810                 kmemleak_ignore(ptr);
2811                 if (!ptr) {
2812                         module_free(mod, mod->module_core);
2813                         return -ENOMEM;
2814                 }
2815                 memset(ptr, 0, mod->init_size);
2816                 mod->module_init = ptr;
2817         } else
2818                 mod->module_init = NULL;
2819 
2820         /* Transfer each section which specifies SHF_ALLOC */
2821         pr_debug("final section addresses:\n");
2822         for (i = 0; i < info->hdr->e_shnum; i++) {
2823                 void *dest;
2824                 Elf_Shdr *shdr = &info->sechdrs[i];
2825 
2826                 if (!(shdr->sh_flags & SHF_ALLOC))
2827                         continue;
2828 
2829                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2830                         dest = mod->module_init
2831                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2832                 else
2833                         dest = mod->module_core + shdr->sh_entsize;
2834 
2835                 if (shdr->sh_type != SHT_NOBITS)
2836                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2837                 /* Update sh_addr to point to copy in image. */
2838                 shdr->sh_addr = (unsigned long)dest;
2839                 pr_debug("\t0x%lx %s\n",
2840                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2841         }
2842 
2843         return 0;
2844 }
2845 
2846 static int check_module_license_and_versions(struct module *mod)
2847 {
2848         /*
2849          * ndiswrapper is under GPL by itself, but loads proprietary modules.
2850          * Don't use add_taint_module(), as it would prevent ndiswrapper from
2851          * using GPL-only symbols it needs.
2852          */
2853         if (strcmp(mod->name, "ndiswrapper") == 0)
2854                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2855 
2856         /* driverloader was caught wrongly pretending to be under GPL */
2857         if (strcmp(mod->name, "driverloader") == 0)
2858                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2859                                  LOCKDEP_NOW_UNRELIABLE);
2860 
2861         /* lve claims to be GPL but upstream won't provide source */
2862         if (strcmp(mod->name, "lve") == 0)
2863                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2864                                  LOCKDEP_NOW_UNRELIABLE);
2865 
2866 #ifdef CONFIG_MODVERSIONS
2867         if ((mod->num_syms && !mod->crcs)
2868             || (mod->num_gpl_syms && !mod->gpl_crcs)
2869             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2870 #ifdef CONFIG_UNUSED_SYMBOLS
2871             || (mod->num_unused_syms && !mod->unused_crcs)
2872             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2873 #endif
2874                 ) {
2875                 return try_to_force_load(mod,
2876                                          "no versions for exported symbols");
2877         }
2878 #endif
2879         return 0;
2880 }
2881 
2882 static void flush_module_icache(const struct module *mod)
2883 {
2884         mm_segment_t old_fs;
2885 
2886         /* flush the icache in correct context */
2887         old_fs = get_fs();
2888         set_fs(KERNEL_DS);
2889 
2890         /*
2891          * Flush the instruction cache, since we've played with text.
2892          * Do it before processing of module parameters, so the module
2893          * can provide parameter accessor functions of its own.
2894          */
2895         if (mod->module_init)
2896                 flush_icache_range((unsigned long)mod->module_init,
2897                                    (unsigned long)mod->module_init
2898                                    + mod->init_size);
2899         flush_icache_range((unsigned long)mod->module_core,
2900                            (unsigned long)mod->module_core + mod->core_size);
2901 
2902         set_fs(old_fs);
2903 }
2904 
2905 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2906                                      Elf_Shdr *sechdrs,
2907                                      char *secstrings,
2908                                      struct module *mod)
2909 {
2910         return 0;
2911 }
2912 
2913 static struct module *layout_and_allocate(struct load_info *info, int flags)
2914 {
2915         /* Module within temporary copy. */
2916         struct module *mod;
2917         int err;
2918 
2919         mod = setup_load_info(info, flags);
2920         if (IS_ERR(mod))
2921                 return mod;
2922 
2923         err = check_modinfo(mod, info, flags);
2924         if (err)
2925                 return ERR_PTR(err);
2926 
2927         /* Allow arches to frob section contents and sizes.  */
2928         err = module_frob_arch_sections(info->hdr, info->sechdrs,
2929                                         info->secstrings, mod);
2930         if (err < 0)
2931                 return ERR_PTR(err);
2932 
2933         /* We will do a special allocation for per-cpu sections later. */
2934         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2935 
2936         /* Determine total sizes, and put offsets in sh_entsize.  For now
2937            this is done generically; there doesn't appear to be any
2938            special cases for the architectures. */
2939         layout_sections(mod, info);
2940         layout_symtab(mod, info);
2941 
2942         /* Allocate and move to the final place */
2943         err = move_module(mod, info);
2944         if (err)
2945                 return ERR_PTR(err);
2946 
2947         /* Module has been copied to its final place now: return it. */
2948         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2949         kmemleak_load_module(mod, info);
2950         return mod;
2951 }
2952 
2953 /* mod is no longer valid after this! */
2954 static void module_deallocate(struct module *mod, struct load_info *info)
2955 {
2956         percpu_modfree(mod);
2957         module_free(mod, mod->module_init);
2958         module_free(mod, mod->module_core);
2959 }
2960 
2961 int __weak module_finalize(const Elf_Ehdr *hdr,
2962                            const Elf_Shdr *sechdrs,
2963                            struct module *me)
2964 {
2965         return 0;
2966 }
2967 
2968 static int post_relocation(struct module *mod, const struct load_info *info)
2969 {
2970         /* Sort exception table now relocations are done. */
2971         sort_extable(mod->extable, mod->extable + mod->num_exentries);
2972 
2973         /* Copy relocated percpu area over. */
2974         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2975                        info->sechdrs[info->index.pcpu].sh_size);
2976 
2977         /* Setup kallsyms-specific fields. */
2978         add_kallsyms(mod, info);
2979 
2980         /* Arch-specific module finalizing. */
2981         return module_finalize(info->hdr, info->sechdrs, mod);
2982 }
2983 
2984 /* Is this module of this name done loading?  No locks held. */
2985 static bool finished_loading(const char *name)
2986 {
2987         struct module *mod;
2988         bool ret;
2989 
2990         mutex_lock(&module_mutex);
2991         mod = find_module_all(name, strlen(name), true);
2992         ret = !mod || mod->state == MODULE_STATE_LIVE
2993                 || mod->state == MODULE_STATE_GOING;
2994         mutex_unlock(&module_mutex);
2995 
2996         return ret;
2997 }
2998 
2999 /* Call module constructors. */
3000 static void do_mod_ctors(struct module *mod)
3001 {
3002 #ifdef CONFIG_CONSTRUCTORS
3003         unsigned long i;
3004 
3005         for (i = 0; i < mod->num_ctors; i++)
3006                 mod->ctors[i]();
3007 #endif
3008 }
3009 
3010 /* This is where the real work happens */
3011 static int do_init_module(struct module *mod)
3012 {
3013         int ret = 0;
3014 
3015         /*
3016          * We want to find out whether @mod uses async during init.  Clear
3017          * PF_USED_ASYNC.  async_schedule*() will set it.
3018          */
3019         current->flags &= ~PF_USED_ASYNC;
3020 
3021         do_mod_ctors(mod);
3022         /* Start the module */
3023         if (mod->init != NULL)
3024                 ret = do_one_initcall(mod->init);
3025         if (ret < 0) {
3026                 /* Init routine failed: abort.  Try to protect us from
3027                    buggy refcounters. */
3028                 mod->state = MODULE_STATE_GOING;
3029                 synchronize_sched();
3030                 module_put(mod);
3031                 blocking_notifier_call_chain(&module_notify_list,
3032                                              MODULE_STATE_GOING, mod);
3033                 free_module(mod);
3034                 wake_up_all(&module_wq);
3035                 return ret;
3036         }
3037         if (ret > 0) {
3038                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3039                         "follow 0/-E convention\n"
3040                         "%s: loading module anyway...\n",
3041                         __func__, mod->name, ret, __func__);
3042                 dump_stack();
3043         }
3044 
3045         /* Now it's a first class citizen! */
3046         mod->state = MODULE_STATE_LIVE;
3047         blocking_notifier_call_chain(&module_notify_list,
3048                                      MODULE_STATE_LIVE, mod);
3049 
3050         /*
3051          * We need to finish all async code before the module init sequence
3052          * is done.  This has potential to deadlock.  For example, a newly
3053          * detected block device can trigger request_module() of the
3054          * default iosched from async probing task.  Once userland helper
3055          * reaches here, async_synchronize_full() will wait on the async
3056          * task waiting on request_module() and deadlock.
3057          *
3058          * This deadlock is avoided by perfomring async_synchronize_full()
3059          * iff module init queued any async jobs.  This isn't a full
3060          * solution as it will deadlock the same if module loading from
3061          * async jobs nests more than once; however, due to the various
3062          * constraints, this hack seems to be the best option for now.
3063          * Please refer to the following thread for details.
3064          *
3065          * http://thread.gmane.org/gmane.linux.kernel/1420814
3066          */
3067         if (current->flags & PF_USED_ASYNC)
3068                 async_synchronize_full();
3069 
3070         mutex_lock(&module_mutex);
3071         /* Drop initial reference. */
3072         module_put(mod);
3073         trim_init_extable(mod);
3074 #ifdef CONFIG_KALLSYMS
3075         mod->num_symtab = mod->core_num_syms;
3076         mod->symtab = mod->core_symtab;
3077         mod->strtab = mod->core_strtab;
3078 #endif
3079         unset_module_init_ro_nx(mod);
3080         module_free(mod, mod->module_init);
3081         mod->module_init = NULL;
3082         mod->init_size = 0;
3083         mod->init_ro_size = 0;
3084         mod->init_text_size = 0;
3085         mutex_unlock(&module_mutex);
3086         wake_up_all(&module_wq);
3087 
3088         return 0;
3089 }
3090 
3091 static int may_init_module(void)
3092 {
3093         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3094                 return -EPERM;
3095 
3096         return 0;
3097 }
3098 
3099 /*
3100  * We try to place it in the list now to make sure it's unique before
3101  * we dedicate too many resources.  In particular, temporary percpu
3102  * memory exhaustion.
3103  */
3104 static int add_unformed_module(struct module *mod)
3105 {
3106         int err;
3107         struct module *old;
3108 
3109         mod->state = MODULE_STATE_UNFORMED;
3110 
3111 again:
3112         mutex_lock(&module_mutex);
3113         old = find_module_all(mod->name, strlen(mod->name), true);
3114         if (old != NULL) {
3115                 if (old->state == MODULE_STATE_COMING
3116                     || old->state == MODULE_STATE_UNFORMED) {
3117                         /* Wait in case it fails to load. */
3118                         mutex_unlock(&module_mutex);
3119                         err = wait_event_interruptible(module_wq,
3120                                                finished_loading(mod->name));
3121                         if (err)
3122                                 goto out_unlocked;
3123                         goto again;
3124                 }
3125                 err = -EEXIST;
3126                 goto out;
3127         }
3128         list_add_rcu(&mod->list, &modules);
3129         err = 0;
3130 
3131 out:
3132         mutex_unlock(&module_mutex);
3133 out_unlocked:
3134         return err;
3135 }
3136 
3137 static int complete_formation(struct module *mod, struct load_info *info)
3138 {
3139         int err;
3140 
3141         mutex_lock(&module_mutex);
3142 
3143         /* Find duplicate symbols (must be called under lock). */
3144         err = verify_export_symbols(mod);
3145         if (err < 0)
3146                 goto out;
3147 
3148         /* This relies on module_mutex for list integrity. */
3149         module_bug_finalize(info->hdr, info->sechdrs, mod);
3150 
3151         /* Set RO and NX regions for core */
3152         set_section_ro_nx(mod->module_core,
3153                                 mod->core_text_size,
3154                                 mod->core_ro_size,
3155                                 mod->core_size);
3156 
3157         /* Set RO and NX regions for init */
3158         set_section_ro_nx(mod->module_init,
3159                                 mod->init_text_size,
3160                                 mod->init_ro_size,
3161                                 mod->init_size);
3162 
3163         /* Mark state as coming so strong_try_module_get() ignores us,
3164          * but kallsyms etc. can see us. */
3165         mod->state = MODULE_STATE_COMING;
3166         mutex_unlock(&module_mutex);
3167 
3168         blocking_notifier_call_chain(&module_notify_list,
3169                                      MODULE_STATE_COMING, mod);
3170         return 0;
3171 
3172 out:
3173         mutex_unlock(&module_mutex);
3174         return err;
3175 }
3176 
3177 static int unknown_module_param_cb(char *param, char *val, const char *modname)
3178 {
3179         /* Check for magic 'dyndbg' arg */ 
3180         int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3181         if (ret != 0)
3182                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3183         return 0;
3184 }
3185 
3186 /* Allocate and load the module: note that size of section 0 is always
3187    zero, and we rely on this for optional sections. */
3188 static int load_module(struct load_info *info, const char __user *uargs,
3189                        int flags)
3190 {
3191         struct module *mod;
3192         long err;
3193         char *after_dashes;
3194 
3195         err = module_sig_check(info);
3196         if (err)
3197                 goto free_copy;
3198 
3199         err = elf_header_check(info);
3200         if (err)
3201                 goto free_copy;
3202 
3203         /* Figure out module layout, and allocate all the memory. */
3204         mod = layout_and_allocate(info, flags);
3205         if (IS_ERR(mod)) {
3206                 err = PTR_ERR(mod);
3207                 goto free_copy;
3208         }
3209 
3210         /* Reserve our place in the list. */
3211         err = add_unformed_module(mod);
3212         if (err)
3213                 goto free_module;
3214 
3215 #ifdef CONFIG_MODULE_SIG
3216         mod->sig_ok = info->sig_ok;
3217         if (!mod->sig_ok) {
3218                 pr_notice_once("%s: module verification failed: signature "
3219                                "and/or  required key missing - tainting "
3220                                "kernel\n", mod->name);
3221                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3222         }
3223 #endif
3224 
3225         /* To avoid stressing percpu allocator, do this once we're unique. */
3226         err = percpu_modalloc(mod, info);
3227         if (err)
3228                 goto unlink_mod;
3229 
3230         /* Now module is in final location, initialize linked lists, etc. */
3231         err = module_unload_init(mod);
3232         if (err)
3233                 goto unlink_mod;
3234 
3235         /* Now we've got everything in the final locations, we can
3236          * find optional sections. */
3237         err = find_module_sections(mod, info);
3238         if (err)
3239                 goto free_unload;
3240 
3241         err = check_module_license_and_versions(mod);
3242         if (err)
3243                 goto free_unload;
3244 
3245         /* Set up MODINFO_ATTR fields */
3246         setup_modinfo(mod, info);
3247 
3248         /* Fix up syms, so that st_value is a pointer to location. */
3249         err = simplify_symbols(mod, info);
3250         if (err < 0)
3251                 goto free_modinfo;
3252 
3253         err = apply_relocations(mod, info);
3254         if (err < 0)
3255                 goto free_modinfo;
3256 
3257         err = post_relocation(mod, info);
3258         if (err < 0)
3259                 goto free_modinfo;
3260 
3261         flush_module_icache(mod);
3262 
3263         /* Now copy in args */
3264         mod->args = strndup_user(uargs, ~0UL >> 1);
3265         if (IS_ERR(mod->args)) {
3266                 err = PTR_ERR(mod->args);
3267                 goto free_arch_cleanup;
3268         }
3269 
3270         dynamic_debug_setup(info->debug, info->num_debug);
3271 
3272         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3273         ftrace_module_init(mod);
3274 
3275         /* Finally it's fully formed, ready to start executing. */
3276         err = complete_formation(mod, info);
3277         if (err)
3278                 goto ddebug_cleanup;
3279 
3280         /* Module is ready to execute: parsing args may do that. */
3281         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3282                                   -32768, 32767, unknown_module_param_cb);
3283         if (IS_ERR(after_dashes)) {
3284                 err = PTR_ERR(after_dashes);
3285                 goto bug_cleanup;
3286         } else if (after_dashes) {
3287                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3288                        mod->name, after_dashes);
3289         }
3290 
3291         /* Link in to syfs. */
3292         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3293         if (err < 0)
3294                 goto bug_cleanup;
3295 
3296         /* Get rid of temporary copy. */
3297         free_copy(info);
3298 
3299         /* Done! */
3300         trace_module_load(mod);
3301 
3302         return do_init_module(mod);
3303 
3304  bug_cleanup:
3305         /* module_bug_cleanup needs module_mutex protection */
3306         mutex_lock(&module_mutex);
3307         module_bug_cleanup(mod);
3308         mutex_unlock(&module_mutex);
3309 
3310         /* we can't deallocate the module until we clear memory protection */
3311         unset_module_init_ro_nx(mod);
3312         unset_module_core_ro_nx(mod);
3313 
3314  ddebug_cleanup:
3315         dynamic_debug_remove(info->debug);
3316         synchronize_sched();
3317         kfree(mod->args);
3318  free_arch_cleanup:
3319         module_arch_cleanup(mod);
3320  free_modinfo:
3321         free_modinfo(mod);
3322  free_unload:
3323         module_unload_free(mod);
3324  unlink_mod:
3325         mutex_lock(&module_mutex);
3326         /* Unlink carefully: kallsyms could be walking list. */
3327         list_del_rcu(&mod->list);
3328         wake_up_all(&module_wq);
3329         mutex_unlock(&module_mutex);
3330  free_module:
3331         module_deallocate(mod, info);
3332  free_copy:
3333         free_copy(info);
3334         return err;
3335 }
3336 
3337 SYSCALL_DEFINE3(init_module, void __user *, umod,
3338                 unsigned long, len, const char __user *, uargs)
3339 {
3340         int err;
3341         struct load_info info = { };
3342 
3343         err = may_init_module();
3344         if (err)
3345                 return err;
3346 
3347         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3348                umod, len, uargs);
3349 
3350         err = copy_module_from_user(umod, len, &info);
3351         if (err)
3352                 return err;
3353 
3354         return load_module(&info, uargs, 0);
3355 }
3356 
3357 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3358 {
3359         int err;
3360         struct load_info info = { };
3361 
3362         err = may_init_module();
3363         if (err)
3364                 return err;
3365 
3366         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3367 
3368         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3369                       |MODULE_INIT_IGNORE_VERMAGIC))
3370                 return -EINVAL;
3371 
3372         err = copy_module_from_fd(fd, &info);
3373         if (err)
3374                 return err;
3375 
3376         return load_module(&info, uargs, flags);
3377 }
3378 
3379 static inline int within(unsigned long addr, void *start, unsigned long size)
3380 {
3381         return ((void *)addr >= start && (void *)addr < start + size);
3382 }
3383 
3384 #ifdef CONFIG_KALLSYMS
3385 /*
3386  * This ignores the intensely annoying "mapping symbols" found
3387  * in ARM ELF files: $a, $t and $d.
3388  */
3389 static inline int is_arm_mapping_symbol(const char *str)
3390 {
3391         if (str[0] == '.' && str[1] == 'L')
3392                 return true;
3393         return str[0] == '$' && strchr("axtd", str[1])
3394                && (str[2] == '\0' || str[2] == '.');
3395 }
3396 
3397 static const char *get_ksymbol(struct module *mod,
3398                                unsigned long addr,
3399                                unsigned long *size,
3400                                unsigned long *offset)
3401 {
3402         unsigned int i, best = 0;
3403         unsigned long nextval;
3404 
3405         /* At worse, next value is at end of module */
3406         if (within_module_init(addr, mod))
3407                 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3408         else
3409                 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3410 
3411         /* Scan for closest preceding symbol, and next symbol. (ELF
3412            starts real symbols at 1). */
3413         for (i = 1; i < mod->num_symtab; i++) {
3414                 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3415                         continue;
3416 
3417                 /* We ignore unnamed symbols: they're uninformative
3418                  * and inserted at a whim. */
3419                 if (mod->symtab[i].st_value <= addr
3420                     && mod->symtab[i].st_value > mod->symtab[best].st_value
3421                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3422                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3423                         best = i;
3424                 if (mod->symtab[i].st_value > addr
3425                     && mod->symtab[i].st_value < nextval
3426                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3427                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3428                         nextval = mod->symtab[i].st_value;
3429         }
3430 
3431         if (!best)
3432                 return NULL;
3433 
3434         if (size)
3435                 *size = nextval - mod->symtab[best].st_value;
3436         if (offset)
3437                 *offset = addr - mod->symtab[best].st_value;
3438         return mod->strtab + mod->symtab[best].st_name;
3439 }
3440 
3441 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3442  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3443 const char *module_address_lookup(unsigned long addr,
3444                             unsigned long *size,
3445                             unsigned long *offset,
3446                             char **modname,
3447                             char *namebuf)
3448 {
3449         struct module *mod;
3450         const char *ret = NULL;
3451 
3452         preempt_disable();
3453         list_for_each_entry_rcu(mod, &modules, list) {
3454                 if (mod->state == MODULE_STATE_UNFORMED)
3455                         continue;
3456                 if (within_module(addr, mod)) {
3457                         if (modname)
3458                                 *modname = mod->name;
3459                         ret = get_ksymbol(mod, addr, size, offset);
3460                         break;
3461                 }
3462         }
3463         /* Make a copy in here where it's safe */
3464         if (ret) {
3465                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3466                 ret = namebuf;
3467         }
3468         preempt_enable();
3469         return ret;
3470 }
3471 
3472 int lookup_module_symbol_name(unsigned long addr, char *symname)
3473 {
3474         struct module *mod;
3475 
3476         preempt_disable();
3477         list_for_each_entry_rcu(mod, &modules, list) {
3478                 if (mod->state == MODULE_STATE_UNFORMED)
3479                         continue;
3480                 if (within_module(addr, mod)) {
3481                         const char *sym;
3482 
3483                         sym = get_ksymbol(mod, addr, NULL, NULL);
3484                         if (!sym)
3485                                 goto out;
3486                         strlcpy(symname, sym, KSYM_NAME_LEN);
3487                         preempt_enable();
3488                         return 0;
3489                 }
3490         }
3491 out:
3492         preempt_enable();
3493         return -ERANGE;
3494 }
3495 
3496 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3497                         unsigned long *offset, char *modname, char *name)
3498 {
3499         struct module *mod;
3500 
3501         preempt_disable();
3502         list_for_each_entry_rcu(mod, &modules, list) {
3503                 if (mod->state == MODULE_STATE_UNFORMED)
3504                         continue;
3505                 if (within_module(addr, mod)) {
3506                         const char *sym;
3507 
3508                         sym = get_ksymbol(mod, addr, size, offset);
3509                         if (!sym)
3510                                 goto out;
3511                         if (modname)
3512                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3513                         if (name)
3514                                 strlcpy(name, sym, KSYM_NAME_LEN);
3515                         preempt_enable();
3516                         return 0;
3517                 }
3518         }
3519 out:
3520         preempt_enable();
3521         return -ERANGE;
3522 }
3523 
3524 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3525                         char *name, char *module_name, int *exported)
3526 {
3527         struct module *mod;
3528 
3529         preempt_disable();
3530         list_for_each_entry_rcu(mod, &modules, list) {
3531                 if (mod->state == MODULE_STATE_UNFORMED)
3532                         continue;
3533                 if (symnum < mod->num_symtab) {
3534                         *value = mod->symtab[symnum].st_value;
3535                         *type = mod->symtab[symnum].st_info;
3536                         strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3537                                 KSYM_NAME_LEN);
3538                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3539                         *exported = is_exported(name, *value, mod);
3540                         preempt_enable();
3541                         return 0;
3542                 }
3543                 symnum -= mod->num_symtab;
3544         }
3545         preempt_enable();
3546         return -ERANGE;
3547 }
3548 
3549 static unsigned long mod_find_symname(struct module *mod, const char *name)
3550 {
3551         unsigned int i;
3552 
3553         for (i = 0; i < mod->num_symtab; i++)
3554                 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3555                     mod->symtab[i].st_info != 'U')
3556                         return mod->symtab[i].st_value;
3557         return 0;
3558 }
3559 
3560 /* Look for this name: can be of form module:name. */
3561 unsigned long module_kallsyms_lookup_name(const char *name)
3562 {
3563         struct module *mod;
3564         char *colon;
3565         unsigned long ret = 0;
3566 
3567         /* Don't lock: we're in enough trouble already. */
3568         preempt_disable();
3569         if ((colon = strchr(name, ':')) != NULL) {
3570                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3571                         ret = mod_find_symname(mod, colon+1);
3572         } else {
3573                 list_for_each_entry_rcu(mod, &modules, list) {
3574                         if (mod->state == MODULE_STATE_UNFORMED)
3575                                 continue;
3576                         if ((ret = mod_find_symname(mod, name)) != 0)
3577                                 break;
3578                 }
3579         }
3580         preempt_enable();
3581         return ret;
3582 }
3583 
3584 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3585                                              struct module *, unsigned long),
3586                                    void *data)
3587 {
3588         struct module *mod;
3589         unsigned int i;
3590         int ret;
3591 
3592         list_for_each_entry(mod, &modules, list) {
3593                 if (mod->state == MODULE_STATE_UNFORMED)
3594                         continue;
3595                 for (i = 0; i < mod->num_symtab; i++) {
3596                         ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3597                                  mod, mod->symtab[i].st_value);
3598                         if (ret != 0)
3599                                 return ret;
3600                 }
3601         }
3602         return 0;
3603 }
3604 #endif /* CONFIG_KALLSYMS */
3605 
3606 static char *module_flags(struct module *mod, char *buf)
3607 {
3608         int bx = 0;
3609 
3610         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3611         if (mod->taints ||
3612             mod->state == MODULE_STATE_GOING ||
3613             mod->state == MODULE_STATE_COMING) {
3614                 buf[bx++] = '(';
3615                 bx += module_flags_taint(mod, buf + bx);
3616                 /* Show a - for module-is-being-unloaded */
3617                 if (mod->state == MODULE_STATE_GOING)
3618                         buf[bx++] = '-';
3619                 /* Show a + for module-is-being-loaded */
3620                 if (mod->state == MODULE_STATE_COMING)
3621                         buf[bx++] = '+';
3622                 buf[bx++] = ')';
3623         }
3624         buf[bx] = '\0';
3625 
3626         return buf;
3627 }
3628 
3629 #ifdef CONFIG_PROC_FS
3630 /* Called by the /proc file system to return a list of modules. */
3631 static void *m_start(struct seq_file *m, loff_t *pos)
3632 {
3633         mutex_lock(&module_mutex);
3634         return seq_list_start(&modules, *pos);
3635 }
3636 
3637 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3638 {
3639         return seq_list_next(p, &modules, pos);
3640 }
3641 
3642 static void m_stop(struct seq_file *m, void *p)
3643 {
3644         mutex_unlock(&module_mutex);
3645 }
3646 
3647 static int m_show(struct seq_file *m, void *p)
3648 {
3649         struct module *mod = list_entry(p, struct module, list);
3650         char buf[8];
3651 
3652         /* We always ignore unformed modules. */
3653         if (mod->state == MODULE_STATE_UNFORMED)
3654                 return 0;
3655 
3656         seq_printf(m, "%s %u",
3657                    mod->name, mod->init_size + mod->core_size);
3658         print_unload_info(m, mod);
3659 
3660         /* Informative for users. */
3661         seq_printf(m, " %s",
3662                    mod->state == MODULE_STATE_GOING ? "Unloading":
3663                    mod->state == MODULE_STATE_COMING ? "Loading":
3664                    "Live");
3665         /* Used by oprofile and other similar tools. */
3666         seq_printf(m, " 0x%pK", mod->module_core);
3667 
3668         /* Taints info */
3669         if (mod->taints)
3670                 seq_printf(m, " %s", module_flags(mod, buf));
3671 
3672         seq_printf(m, "\n");
3673         return 0;
3674 }
3675 
3676 /* Format: modulename size refcount deps address
3677 
3678    Where refcount is a number or -, and deps is a comma-separated list
3679    of depends or -.
3680 */
3681 static const struct seq_operations modules_op = {
3682         .start  = m_start,
3683         .next   = m_next,
3684         .stop   = m_stop,
3685         .show   = m_show
3686 };
3687 
3688 static int modules_open(struct inode *inode, struct file *file)
3689 {
3690         return seq_open(file, &modules_op);
3691 }
3692 
3693 static const struct file_operations proc_modules_operations = {
3694         .open           = modules_open,
3695         .read           = seq_read,
3696         .llseek         = seq_lseek,
3697         .release        = seq_release,
3698 };
3699 
3700 static int __init proc_modules_init(void)
3701 {
3702         proc_create("modules", 0, NULL, &proc_modules_operations);
3703         return 0;
3704 }
3705 module_init(proc_modules_init);
3706 #endif
3707 
3708 /* Given an address, look for it in the module exception tables. */
3709 const struct exception_table_entry *search_module_extables(unsigned long addr)
3710 {
3711         const struct exception_table_entry *e = NULL;
3712         struct module *mod;
3713 
3714         preempt_disable();
3715         list_for_each_entry_rcu(mod, &modules, list) {
3716                 if (mod->state == MODULE_STATE_UNFORMED)
3717                         continue;
3718                 if (mod->num_exentries == 0)
3719                         continue;
3720 
3721                 e = search_extable(mod->extable,
3722                                    mod->extable + mod->num_exentries - 1,
3723                                    addr);
3724                 if (e)
3725                         break;
3726         }
3727         preempt_enable();
3728 
3729         /* Now, if we found one, we are running inside it now, hence
3730            we cannot unload the module, hence no refcnt needed. */
3731         return e;
3732 }
3733 
3734 /*
3735  * is_module_address - is this address inside a module?
3736  * @addr: the address to check.
3737  *
3738  * See is_module_text_address() if you simply want to see if the address
3739  * is code (not data).
3740  */
3741 bool is_module_address(unsigned long addr)
3742 {
3743         bool ret;
3744 
3745         preempt_disable();
3746         ret = __module_address(addr) != NULL;
3747         preempt_enable();
3748 
3749         return ret;
3750 }
3751 
3752 /*
3753  * __module_address - get the module which contains an address.
3754  * @addr: the address.
3755  *
3756  * Must be called with preempt disabled or module mutex held so that
3757  * module doesn't get freed during this.
3758  */
3759 struct module *__module_address(unsigned long addr)
3760 {
3761         struct module *mod;
3762 
3763         if (addr < module_addr_min || addr > module_addr_max)
3764                 return NULL;
3765 
3766         list_for_each_entry_rcu(mod, &modules, list) {
3767                 if (mod->state == MODULE_STATE_UNFORMED)
3768                         continue;
3769                 if (within_module(addr, mod))
3770                         return mod;
3771         }
3772         return NULL;
3773 }
3774 EXPORT_SYMBOL_GPL(__module_address);
3775 
3776 /*
3777  * is_module_text_address - is this address inside module code?
3778  * @addr: the address to check.
3779  *
3780  * See is_module_address() if you simply want to see if the address is
3781  * anywhere in a module.  See kernel_text_address() for testing if an
3782  * address corresponds to kernel or module code.
3783  */
3784 bool is_module_text_address(unsigned long addr)
3785 {
3786         bool ret;
3787 
3788         preempt_disable();
3789         ret = __module_text_address(addr) != NULL;
3790         preempt_enable();
3791 
3792         return ret;
3793 }
3794 
3795 /*
3796  * __module_text_address - get the module whose code contains an address.
3797  * @addr: the address.
3798  *
3799  * Must be called with preempt disabled or module mutex held so that
3800  * module doesn't get freed during this.
3801  */
3802 struct module *__module_text_address(unsigned long addr)
3803 {
3804         struct module *mod = __module_address(addr);
3805         if (mod) {
3806                 /* Make sure it's within the text section. */
3807                 if (!within(addr, mod->module_init, mod->init_text_size)
3808                     && !within(addr, mod->module_core, mod->core_text_size))
3809                         mod = NULL;
3810         }
3811         return mod;
3812 }
3813 EXPORT_SYMBOL_GPL(__module_text_address);
3814 
3815 /* Don't grab lock, we're oopsing. */
3816 void print_modules(void)
3817 {
3818         struct module *mod;
3819         char buf[8];
3820 
3821         printk(KERN_DEFAULT "Modules linked in:");
3822         /* Most callers should already have preempt disabled, but make sure */
3823         preempt_disable();
3824         list_for_each_entry_rcu(mod, &modules, list) {
3825                 if (mod->state == MODULE_STATE_UNFORMED)
3826                         continue;
3827                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
3828         }
3829         preempt_enable();
3830         if (last_unloaded_module[0])
3831                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
3832         pr_cont("\n");
3833 }
3834 
3835 #ifdef CONFIG_MODVERSIONS
3836 /* Generate the signature for all relevant module structures here.
3837  * If these change, we don't want to try to parse the module. */
3838 void module_layout(struct module *mod,
3839                    struct modversion_info *ver,
3840                    struct kernel_param *kp,
3841                    struct kernel_symbol *ks,
3842                    struct tracepoint * const *tp)
3843 {
3844 }
3845 EXPORT_SYMBOL(module_layout);
3846 #endif
3847 

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