Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

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_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         mod->state = MODULE_STATE_UNFORMED;
1846 
1847         /* Remove dynamic debug info */
1848         ddebug_remove_module(mod->name);
1849 
1850         /* Arch-specific cleanup. */
1851         module_arch_cleanup(mod);
1852 
1853         /* Module unload stuff */
1854         module_unload_free(mod);
1855 
1856         /* Free any allocated parameters. */
1857         destroy_params(mod->kp, mod->num_kp);
1858 
1859         /* Now we can delete it from the lists */
1860         mutex_lock(&module_mutex);
1861         stop_machine(__unlink_module, mod, NULL);
1862         mutex_unlock(&module_mutex);
1863 
1864         /* This may be NULL, but that's OK */
1865         unset_module_init_ro_nx(mod);
1866         module_free(mod, mod->module_init);
1867         kfree(mod->args);
1868         percpu_modfree(mod);
1869 
1870         /* Free lock-classes: */
1871         lockdep_free_key_range(mod->module_core, mod->core_size);
1872 
1873         /* Finally, free the core (containing the module structure) */
1874         unset_module_core_ro_nx(mod);
1875         module_free(mod, mod->module_core);
1876 
1877 #ifdef CONFIG_MPU
1878         update_protections(current->mm);
1879 #endif
1880 }
1881 
1882 void *__symbol_get(const char *symbol)
1883 {
1884         struct module *owner;
1885         const struct kernel_symbol *sym;
1886 
1887         preempt_disable();
1888         sym = find_symbol(symbol, &owner, NULL, true, true);
1889         if (sym && strong_try_module_get(owner))
1890                 sym = NULL;
1891         preempt_enable();
1892 
1893         return sym ? (void *)sym->value : NULL;
1894 }
1895 EXPORT_SYMBOL_GPL(__symbol_get);
1896 
1897 /*
1898  * Ensure that an exported symbol [global namespace] does not already exist
1899  * in the kernel or in some other module's exported symbol table.
1900  *
1901  * You must hold the module_mutex.
1902  */
1903 static int verify_export_symbols(struct module *mod)
1904 {
1905         unsigned int i;
1906         struct module *owner;
1907         const struct kernel_symbol *s;
1908         struct {
1909                 const struct kernel_symbol *sym;
1910                 unsigned int num;
1911         } arr[] = {
1912                 { mod->syms, mod->num_syms },
1913                 { mod->gpl_syms, mod->num_gpl_syms },
1914                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1915 #ifdef CONFIG_UNUSED_SYMBOLS
1916                 { mod->unused_syms, mod->num_unused_syms },
1917                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1918 #endif
1919         };
1920 
1921         for (i = 0; i < ARRAY_SIZE(arr); i++) {
1922                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1923                         if (find_symbol(s->name, &owner, NULL, true, false)) {
1924                                 pr_err("%s: exports duplicate symbol %s"
1925                                        " (owned by %s)\n",
1926                                        mod->name, s->name, module_name(owner));
1927                                 return -ENOEXEC;
1928                         }
1929                 }
1930         }
1931         return 0;
1932 }
1933 
1934 /* Change all symbols so that st_value encodes the pointer directly. */
1935 static int simplify_symbols(struct module *mod, const struct load_info *info)
1936 {
1937         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1938         Elf_Sym *sym = (void *)symsec->sh_addr;
1939         unsigned long secbase;
1940         unsigned int i;
1941         int ret = 0;
1942         const struct kernel_symbol *ksym;
1943 
1944         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1945                 const char *name = info->strtab + sym[i].st_name;
1946 
1947                 switch (sym[i].st_shndx) {
1948                 case SHN_COMMON:
1949                         /* Ignore common symbols */
1950                         if (!strncmp(name, "__gnu_lto", 9))
1951                                 break;
1952 
1953                         /* We compiled with -fno-common.  These are not
1954                            supposed to happen.  */
1955                         pr_debug("Common symbol: %s\n", name);
1956                         printk("%s: please compile with -fno-common\n",
1957                                mod->name);
1958                         ret = -ENOEXEC;
1959                         break;
1960 
1961                 case SHN_ABS:
1962                         /* Don't need to do anything */
1963                         pr_debug("Absolute symbol: 0x%08lx\n",
1964                                (long)sym[i].st_value);
1965                         break;
1966 
1967                 case SHN_UNDEF:
1968                         ksym = resolve_symbol_wait(mod, info, name);
1969                         /* Ok if resolved.  */
1970                         if (ksym && !IS_ERR(ksym)) {
1971                                 sym[i].st_value = ksym->value;
1972                                 break;
1973                         }
1974 
1975                         /* Ok if weak.  */
1976                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1977                                 break;
1978 
1979                         pr_warn("%s: Unknown symbol %s (err %li)\n",
1980                                 mod->name, name, PTR_ERR(ksym));
1981                         ret = PTR_ERR(ksym) ?: -ENOENT;
1982                         break;
1983 
1984                 default:
1985                         /* Divert to percpu allocation if a percpu var. */
1986                         if (sym[i].st_shndx == info->index.pcpu)
1987                                 secbase = (unsigned long)mod_percpu(mod);
1988                         else
1989                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1990                         sym[i].st_value += secbase;
1991                         break;
1992                 }
1993         }
1994 
1995         return ret;
1996 }
1997 
1998 static int apply_relocations(struct module *mod, const struct load_info *info)
1999 {
2000         unsigned int i;
2001         int err = 0;
2002 
2003         /* Now do relocations. */
2004         for (i = 1; i < info->hdr->e_shnum; i++) {
2005                 unsigned int infosec = info->sechdrs[i].sh_info;
2006 
2007                 /* Not a valid relocation section? */
2008                 if (infosec >= info->hdr->e_shnum)
2009                         continue;
2010 
2011                 /* Don't bother with non-allocated sections */
2012                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2013                         continue;
2014 
2015                 if (info->sechdrs[i].sh_type == SHT_REL)
2016                         err = apply_relocate(info->sechdrs, info->strtab,
2017                                              info->index.sym, i, mod);
2018                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2019                         err = apply_relocate_add(info->sechdrs, info->strtab,
2020                                                  info->index.sym, i, mod);
2021                 if (err < 0)
2022                         break;
2023         }
2024         return err;
2025 }
2026 
2027 /* Additional bytes needed by arch in front of individual sections */
2028 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2029                                              unsigned int section)
2030 {
2031         /* default implementation just returns zero */
2032         return 0;
2033 }
2034 
2035 /* Update size with this section: return offset. */
2036 static long get_offset(struct module *mod, unsigned int *size,
2037                        Elf_Shdr *sechdr, unsigned int section)
2038 {
2039         long ret;
2040 
2041         *size += arch_mod_section_prepend(mod, section);
2042         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2043         *size = ret + sechdr->sh_size;
2044         return ret;
2045 }
2046 
2047 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2048    might -- code, read-only data, read-write data, small data.  Tally
2049    sizes, and place the offsets into sh_entsize fields: high bit means it
2050    belongs in init. */
2051 static void layout_sections(struct module *mod, struct load_info *info)
2052 {
2053         static unsigned long const masks[][2] = {
2054                 /* NOTE: all executable code must be the first section
2055                  * in this array; otherwise modify the text_size
2056                  * finder in the two loops below */
2057                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2058                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2059                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2060                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2061         };
2062         unsigned int m, i;
2063 
2064         for (i = 0; i < info->hdr->e_shnum; i++)
2065                 info->sechdrs[i].sh_entsize = ~0UL;
2066 
2067         pr_debug("Core section allocation order:\n");
2068         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2069                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2070                         Elf_Shdr *s = &info->sechdrs[i];
2071                         const char *sname = info->secstrings + s->sh_name;
2072 
2073                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2074                             || (s->sh_flags & masks[m][1])
2075                             || s->sh_entsize != ~0UL
2076                             || strstarts(sname, ".init"))
2077                                 continue;
2078                         s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2079                         pr_debug("\t%s\n", sname);
2080                 }
2081                 switch (m) {
2082                 case 0: /* executable */
2083                         mod->core_size = debug_align(mod->core_size);
2084                         mod->core_text_size = mod->core_size;
2085                         break;
2086                 case 1: /* RO: text and ro-data */
2087                         mod->core_size = debug_align(mod->core_size);
2088                         mod->core_ro_size = mod->core_size;
2089                         break;
2090                 case 3: /* whole core */
2091                         mod->core_size = debug_align(mod->core_size);
2092                         break;
2093                 }
2094         }
2095 
2096         pr_debug("Init section allocation order:\n");
2097         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2098                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2099                         Elf_Shdr *s = &info->sechdrs[i];
2100                         const char *sname = info->secstrings + s->sh_name;
2101 
2102                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2103                             || (s->sh_flags & masks[m][1])
2104                             || s->sh_entsize != ~0UL
2105                             || !strstarts(sname, ".init"))
2106                                 continue;
2107                         s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2108                                          | INIT_OFFSET_MASK);
2109                         pr_debug("\t%s\n", sname);
2110                 }
2111                 switch (m) {
2112                 case 0: /* executable */
2113                         mod->init_size = debug_align(mod->init_size);
2114                         mod->init_text_size = mod->init_size;
2115                         break;
2116                 case 1: /* RO: text and ro-data */
2117                         mod->init_size = debug_align(mod->init_size);
2118                         mod->init_ro_size = mod->init_size;
2119                         break;
2120                 case 3: /* whole init */
2121                         mod->init_size = debug_align(mod->init_size);
2122                         break;
2123                 }
2124         }
2125 }
2126 
2127 static void set_license(struct module *mod, const char *license)
2128 {
2129         if (!license)
2130                 license = "unspecified";
2131 
2132         if (!license_is_gpl_compatible(license)) {
2133                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2134                         pr_warn("%s: module license '%s' taints kernel.\n",
2135                                 mod->name, license);
2136                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2137                                  LOCKDEP_NOW_UNRELIABLE);
2138         }
2139 }
2140 
2141 /* Parse tag=value strings from .modinfo section */
2142 static char *next_string(char *string, unsigned long *secsize)
2143 {
2144         /* Skip non-zero chars */
2145         while (string[0]) {
2146                 string++;
2147                 if ((*secsize)-- <= 1)
2148                         return NULL;
2149         }
2150 
2151         /* Skip any zero padding. */
2152         while (!string[0]) {
2153                 string++;
2154                 if ((*secsize)-- <= 1)
2155                         return NULL;
2156         }
2157         return string;
2158 }
2159 
2160 static char *get_modinfo(struct load_info *info, const char *tag)
2161 {
2162         char *p;
2163         unsigned int taglen = strlen(tag);
2164         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2165         unsigned long size = infosec->sh_size;
2166 
2167         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2168                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2169                         return p + taglen + 1;
2170         }
2171         return NULL;
2172 }
2173 
2174 static void setup_modinfo(struct module *mod, struct load_info *info)
2175 {
2176         struct module_attribute *attr;
2177         int i;
2178 
2179         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2180                 if (attr->setup)
2181                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2182         }
2183 }
2184 
2185 static void free_modinfo(struct module *mod)
2186 {
2187         struct module_attribute *attr;
2188         int i;
2189 
2190         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2191                 if (attr->free)
2192                         attr->free(mod);
2193         }
2194 }
2195 
2196 #ifdef CONFIG_KALLSYMS
2197 
2198 /* lookup symbol in given range of kernel_symbols */
2199 static const struct kernel_symbol *lookup_symbol(const char *name,
2200         const struct kernel_symbol *start,
2201         const struct kernel_symbol *stop)
2202 {
2203         return bsearch(name, start, stop - start,
2204                         sizeof(struct kernel_symbol), cmp_name);
2205 }
2206 
2207 static int is_exported(const char *name, unsigned long value,
2208                        const struct module *mod)
2209 {
2210         const struct kernel_symbol *ks;
2211         if (!mod)
2212                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2213         else
2214                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2215         return ks != NULL && ks->value == value;
2216 }
2217 
2218 /* As per nm */
2219 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2220 {
2221         const Elf_Shdr *sechdrs = info->sechdrs;
2222 
2223         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2224                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2225                         return 'v';
2226                 else
2227                         return 'w';
2228         }
2229         if (sym->st_shndx == SHN_UNDEF)
2230                 return 'U';
2231         if (sym->st_shndx == SHN_ABS)
2232                 return 'a';
2233         if (sym->st_shndx >= SHN_LORESERVE)
2234                 return '?';
2235         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2236                 return 't';
2237         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2238             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2239                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2240                         return 'r';
2241                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2242                         return 'g';
2243                 else
2244                         return 'd';
2245         }
2246         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2247                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2248                         return 's';
2249                 else
2250                         return 'b';
2251         }
2252         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2253                       ".debug")) {
2254                 return 'n';
2255         }
2256         return '?';
2257 }
2258 
2259 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2260                            unsigned int shnum)
2261 {
2262         const Elf_Shdr *sec;
2263 
2264         if (src->st_shndx == SHN_UNDEF
2265             || src->st_shndx >= shnum
2266             || !src->st_name)
2267                 return false;
2268 
2269         sec = sechdrs + src->st_shndx;
2270         if (!(sec->sh_flags & SHF_ALLOC)
2271 #ifndef CONFIG_KALLSYMS_ALL
2272             || !(sec->sh_flags & SHF_EXECINSTR)
2273 #endif
2274             || (sec->sh_entsize & INIT_OFFSET_MASK))
2275                 return false;
2276 
2277         return true;
2278 }
2279 
2280 /*
2281  * We only allocate and copy the strings needed by the parts of symtab
2282  * we keep.  This is simple, but has the effect of making multiple
2283  * copies of duplicates.  We could be more sophisticated, see
2284  * linux-kernel thread starting with
2285  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2286  */
2287 static void layout_symtab(struct module *mod, struct load_info *info)
2288 {
2289         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2290         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2291         const Elf_Sym *src;
2292         unsigned int i, nsrc, ndst, strtab_size = 0;
2293 
2294         /* Put symbol section at end of init part of module. */
2295         symsect->sh_flags |= SHF_ALLOC;
2296         symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2297                                          info->index.sym) | INIT_OFFSET_MASK;
2298         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2299 
2300         src = (void *)info->hdr + symsect->sh_offset;
2301         nsrc = symsect->sh_size / sizeof(*src);
2302 
2303         /* Compute total space required for the core symbols' strtab. */
2304         for (ndst = i = 0; i < nsrc; i++) {
2305                 if (i == 0 ||
2306                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2307                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2308                         ndst++;
2309                 }
2310         }
2311 
2312         /* Append room for core symbols at end of core part. */
2313         info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2314         info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2315         mod->core_size += strtab_size;
2316 
2317         /* Put string table section at end of init part of module. */
2318         strsect->sh_flags |= SHF_ALLOC;
2319         strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2320                                          info->index.str) | INIT_OFFSET_MASK;
2321         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2322 }
2323 
2324 static void add_kallsyms(struct module *mod, const struct load_info *info)
2325 {
2326         unsigned int i, ndst;
2327         const Elf_Sym *src;
2328         Elf_Sym *dst;
2329         char *s;
2330         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2331 
2332         mod->symtab = (void *)symsec->sh_addr;
2333         mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2334         /* Make sure we get permanent strtab: don't use info->strtab. */
2335         mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2336 
2337         /* Set types up while we still have access to sections. */
2338         for (i = 0; i < mod->num_symtab; i++)
2339                 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2340 
2341         mod->core_symtab = dst = mod->module_core + info->symoffs;
2342         mod->core_strtab = s = mod->module_core + info->stroffs;
2343         src = mod->symtab;
2344         for (ndst = i = 0; i < mod->num_symtab; i++) {
2345                 if (i == 0 ||
2346                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2347                         dst[ndst] = src[i];
2348                         dst[ndst++].st_name = s - mod->core_strtab;
2349                         s += strlcpy(s, &mod->strtab[src[i].st_name],
2350                                      KSYM_NAME_LEN) + 1;
2351                 }
2352         }
2353         mod->core_num_syms = ndst;
2354 }
2355 #else
2356 static inline void layout_symtab(struct module *mod, struct load_info *info)
2357 {
2358 }
2359 
2360 static void add_kallsyms(struct module *mod, const struct load_info *info)
2361 {
2362 }
2363 #endif /* CONFIG_KALLSYMS */
2364 
2365 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2366 {
2367         if (!debug)
2368                 return;
2369 #ifdef CONFIG_DYNAMIC_DEBUG
2370         if (ddebug_add_module(debug, num, debug->modname))
2371                 pr_err("dynamic debug error adding module: %s\n",
2372                         debug->modname);
2373 #endif
2374 }
2375 
2376 static void dynamic_debug_remove(struct _ddebug *debug)
2377 {
2378         if (debug)
2379                 ddebug_remove_module(debug->modname);
2380 }
2381 
2382 void * __weak module_alloc(unsigned long size)
2383 {
2384         return vmalloc_exec(size);
2385 }
2386 
2387 static void *module_alloc_update_bounds(unsigned long size)
2388 {
2389         void *ret = module_alloc(size);
2390 
2391         if (ret) {
2392                 mutex_lock(&module_mutex);
2393                 /* Update module bounds. */
2394                 if ((unsigned long)ret < module_addr_min)
2395                         module_addr_min = (unsigned long)ret;
2396                 if ((unsigned long)ret + size > module_addr_max)
2397                         module_addr_max = (unsigned long)ret + size;
2398                 mutex_unlock(&module_mutex);
2399         }
2400         return ret;
2401 }
2402 
2403 #ifdef CONFIG_DEBUG_KMEMLEAK
2404 static void kmemleak_load_module(const struct module *mod,
2405                                  const struct load_info *info)
2406 {
2407         unsigned int i;
2408 
2409         /* only scan the sections containing data */
2410         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2411 
2412         for (i = 1; i < info->hdr->e_shnum; i++) {
2413                 /* Scan all writable sections that's not executable */
2414                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2415                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2416                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2417                         continue;
2418 
2419                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2420                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2421         }
2422 }
2423 #else
2424 static inline void kmemleak_load_module(const struct module *mod,
2425                                         const struct load_info *info)
2426 {
2427 }
2428 #endif
2429 
2430 #ifdef CONFIG_MODULE_SIG
2431 static int module_sig_check(struct load_info *info)
2432 {
2433         int err = -ENOKEY;
2434         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2435         const void *mod = info->hdr;
2436 
2437         if (info->len > markerlen &&
2438             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2439                 /* We truncate the module to discard the signature */
2440                 info->len -= markerlen;
2441                 err = mod_verify_sig(mod, &info->len);
2442         }
2443 
2444         if (!err) {
2445                 info->sig_ok = true;
2446                 return 0;
2447         }
2448 
2449         /* Not having a signature is only an error if we're strict. */
2450         if (err == -ENOKEY && !sig_enforce)
2451                 err = 0;
2452 
2453         return err;
2454 }
2455 #else /* !CONFIG_MODULE_SIG */
2456 static int module_sig_check(struct load_info *info)
2457 {
2458         return 0;
2459 }
2460 #endif /* !CONFIG_MODULE_SIG */
2461 
2462 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2463 static int elf_header_check(struct load_info *info)
2464 {
2465         if (info->len < sizeof(*(info->hdr)))
2466                 return -ENOEXEC;
2467 
2468         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2469             || info->hdr->e_type != ET_REL
2470             || !elf_check_arch(info->hdr)
2471             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2472                 return -ENOEXEC;
2473 
2474         if (info->hdr->e_shoff >= info->len
2475             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2476                 info->len - info->hdr->e_shoff))
2477                 return -ENOEXEC;
2478 
2479         return 0;
2480 }
2481 
2482 /* Sets info->hdr and info->len. */
2483 static int copy_module_from_user(const void __user *umod, unsigned long len,
2484                                   struct load_info *info)
2485 {
2486         int err;
2487 
2488         info->len = len;
2489         if (info->len < sizeof(*(info->hdr)))
2490                 return -ENOEXEC;
2491 
2492         err = security_kernel_module_from_file(NULL);
2493         if (err)
2494                 return err;
2495 
2496         /* Suck in entire file: we'll want most of it. */
2497         info->hdr = vmalloc(info->len);
2498         if (!info->hdr)
2499                 return -ENOMEM;
2500 
2501         if (copy_from_user(info->hdr, umod, info->len) != 0) {
2502                 vfree(info->hdr);
2503                 return -EFAULT;
2504         }
2505 
2506         return 0;
2507 }
2508 
2509 /* Sets info->hdr and info->len. */
2510 static int copy_module_from_fd(int fd, struct load_info *info)
2511 {
2512         struct fd f = fdget(fd);
2513         int err;
2514         struct kstat stat;
2515         loff_t pos;
2516         ssize_t bytes = 0;
2517 
2518         if (!f.file)
2519                 return -ENOEXEC;
2520 
2521         err = security_kernel_module_from_file(f.file);
2522         if (err)
2523                 goto out;
2524 
2525         err = vfs_getattr(&f.file->f_path, &stat);
2526         if (err)
2527                 goto out;
2528 
2529         if (stat.size > INT_MAX) {
2530                 err = -EFBIG;
2531                 goto out;
2532         }
2533 
2534         /* Don't hand 0 to vmalloc, it whines. */
2535         if (stat.size == 0) {
2536                 err = -EINVAL;
2537                 goto out;
2538         }
2539 
2540         info->hdr = vmalloc(stat.size);
2541         if (!info->hdr) {
2542                 err = -ENOMEM;
2543                 goto out;
2544         }
2545 
2546         pos = 0;
2547         while (pos < stat.size) {
2548                 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2549                                     stat.size - pos);
2550                 if (bytes < 0) {
2551                         vfree(info->hdr);
2552                         err = bytes;
2553                         goto out;
2554                 }
2555                 if (bytes == 0)
2556                         break;
2557                 pos += bytes;
2558         }
2559         info->len = pos;
2560 
2561 out:
2562         fdput(f);
2563         return err;
2564 }
2565 
2566 static void free_copy(struct load_info *info)
2567 {
2568         vfree(info->hdr);
2569 }
2570 
2571 static int rewrite_section_headers(struct load_info *info, int flags)
2572 {
2573         unsigned int i;
2574 
2575         /* This should always be true, but let's be sure. */
2576         info->sechdrs[0].sh_addr = 0;
2577 
2578         for (i = 1; i < info->hdr->e_shnum; i++) {
2579                 Elf_Shdr *shdr = &info->sechdrs[i];
2580                 if (shdr->sh_type != SHT_NOBITS
2581                     && info->len < shdr->sh_offset + shdr->sh_size) {
2582                         pr_err("Module len %lu truncated\n", info->len);
2583                         return -ENOEXEC;
2584                 }
2585 
2586                 /* Mark all sections sh_addr with their address in the
2587                    temporary image. */
2588                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2589 
2590 #ifndef CONFIG_MODULE_UNLOAD
2591                 /* Don't load .exit sections */
2592                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2593                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2594 #endif
2595         }
2596 
2597         /* Track but don't keep modinfo and version sections. */
2598         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2599                 info->index.vers = 0; /* Pretend no __versions section! */
2600         else
2601                 info->index.vers = find_sec(info, "__versions");
2602         info->index.info = find_sec(info, ".modinfo");
2603         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2604         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2605         return 0;
2606 }
2607 
2608 /*
2609  * Set up our basic convenience variables (pointers to section headers,
2610  * search for module section index etc), and do some basic section
2611  * verification.
2612  *
2613  * Return the temporary module pointer (we'll replace it with the final
2614  * one when we move the module sections around).
2615  */
2616 static struct module *setup_load_info(struct load_info *info, int flags)
2617 {
2618         unsigned int i;
2619         int err;
2620         struct module *mod;
2621 
2622         /* Set up the convenience variables */
2623         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2624         info->secstrings = (void *)info->hdr
2625                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2626 
2627         err = rewrite_section_headers(info, flags);
2628         if (err)
2629                 return ERR_PTR(err);
2630 
2631         /* Find internal symbols and strings. */
2632         for (i = 1; i < info->hdr->e_shnum; i++) {
2633                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2634                         info->index.sym = i;
2635                         info->index.str = info->sechdrs[i].sh_link;
2636                         info->strtab = (char *)info->hdr
2637                                 + info->sechdrs[info->index.str].sh_offset;
2638                         break;
2639                 }
2640         }
2641 
2642         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2643         if (!info->index.mod) {
2644                 pr_warn("No module found in object\n");
2645                 return ERR_PTR(-ENOEXEC);
2646         }
2647         /* This is temporary: point mod into copy of data. */
2648         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2649 
2650         if (info->index.sym == 0) {
2651                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2652                 return ERR_PTR(-ENOEXEC);
2653         }
2654 
2655         info->index.pcpu = find_pcpusec(info);
2656 
2657         /* Check module struct version now, before we try to use module. */
2658         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2659                 return ERR_PTR(-ENOEXEC);
2660 
2661         return mod;
2662 }
2663 
2664 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2665 {
2666         const char *modmagic = get_modinfo(info, "vermagic");
2667         int err;
2668 
2669         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2670                 modmagic = NULL;
2671 
2672         /* This is allowed: modprobe --force will invalidate it. */
2673         if (!modmagic) {
2674                 err = try_to_force_load(mod, "bad vermagic");
2675                 if (err)
2676                         return err;
2677         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2678                 pr_err("%s: version magic '%s' should be '%s'\n",
2679                        mod->name, modmagic, vermagic);
2680                 return -ENOEXEC;
2681         }
2682 
2683         if (!get_modinfo(info, "intree"))
2684                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2685 
2686         if (get_modinfo(info, "staging")) {
2687                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2688                 pr_warn("%s: module is from the staging directory, the quality "
2689                         "is unknown, you have been warned.\n", mod->name);
2690         }
2691 
2692         /* Set up license info based on the info section */
2693         set_license(mod, get_modinfo(info, "license"));
2694 
2695         return 0;
2696 }
2697 
2698 static int find_module_sections(struct module *mod, struct load_info *info)
2699 {
2700         mod->kp = section_objs(info, "__param",
2701                                sizeof(*mod->kp), &mod->num_kp);
2702         mod->syms = section_objs(info, "__ksymtab",
2703                                  sizeof(*mod->syms), &mod->num_syms);
2704         mod->crcs = section_addr(info, "__kcrctab");
2705         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2706                                      sizeof(*mod->gpl_syms),
2707                                      &mod->num_gpl_syms);
2708         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2709         mod->gpl_future_syms = section_objs(info,
2710                                             "__ksymtab_gpl_future",
2711                                             sizeof(*mod->gpl_future_syms),
2712                                             &mod->num_gpl_future_syms);
2713         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2714 
2715 #ifdef CONFIG_UNUSED_SYMBOLS
2716         mod->unused_syms = section_objs(info, "__ksymtab_unused",
2717                                         sizeof(*mod->unused_syms),
2718                                         &mod->num_unused_syms);
2719         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2720         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2721                                             sizeof(*mod->unused_gpl_syms),
2722                                             &mod->num_unused_gpl_syms);
2723         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2724 #endif
2725 #ifdef CONFIG_CONSTRUCTORS
2726         mod->ctors = section_objs(info, ".ctors",
2727                                   sizeof(*mod->ctors), &mod->num_ctors);
2728         if (!mod->ctors)
2729                 mod->ctors = section_objs(info, ".init_array",
2730                                 sizeof(*mod->ctors), &mod->num_ctors);
2731         else if (find_sec(info, ".init_array")) {
2732                 /*
2733                  * This shouldn't happen with same compiler and binutils
2734                  * building all parts of the module.
2735                  */
2736                 printk(KERN_WARNING "%s: has both .ctors and .init_array.\n",
2737                        mod->name);
2738                 return -EINVAL;
2739         }
2740 #endif
2741 
2742 #ifdef CONFIG_TRACEPOINTS
2743         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2744                                              sizeof(*mod->tracepoints_ptrs),
2745                                              &mod->num_tracepoints);
2746 #endif
2747 #ifdef HAVE_JUMP_LABEL
2748         mod->jump_entries = section_objs(info, "__jump_table",
2749                                         sizeof(*mod->jump_entries),
2750                                         &mod->num_jump_entries);
2751 #endif
2752 #ifdef CONFIG_EVENT_TRACING
2753         mod->trace_events = section_objs(info, "_ftrace_events",
2754                                          sizeof(*mod->trace_events),
2755                                          &mod->num_trace_events);
2756 #endif
2757 #ifdef CONFIG_TRACING
2758         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2759                                          sizeof(*mod->trace_bprintk_fmt_start),
2760                                          &mod->num_trace_bprintk_fmt);
2761 #endif
2762 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2763         /* sechdrs[0].sh_size is always zero */
2764         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2765                                              sizeof(*mod->ftrace_callsites),
2766                                              &mod->num_ftrace_callsites);
2767 #endif
2768 
2769         mod->extable = section_objs(info, "__ex_table",
2770                                     sizeof(*mod->extable), &mod->num_exentries);
2771 
2772         if (section_addr(info, "__obsparm"))
2773                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2774 
2775         info->debug = section_objs(info, "__verbose",
2776                                    sizeof(*info->debug), &info->num_debug);
2777 
2778         return 0;
2779 }
2780 
2781 static int move_module(struct module *mod, struct load_info *info)
2782 {
2783         int i;
2784         void *ptr;
2785 
2786         /* Do the allocs. */
2787         ptr = module_alloc_update_bounds(mod->core_size);
2788         /*
2789          * The pointer to this block is stored in the module structure
2790          * which is inside the block. Just mark it as not being a
2791          * leak.
2792          */
2793         kmemleak_not_leak(ptr);
2794         if (!ptr)
2795                 return -ENOMEM;
2796 
2797         memset(ptr, 0, mod->core_size);
2798         mod->module_core = ptr;
2799 
2800         if (mod->init_size) {
2801                 ptr = module_alloc_update_bounds(mod->init_size);
2802                 /*
2803                  * The pointer to this block is stored in the module structure
2804                  * which is inside the block. This block doesn't need to be
2805                  * scanned as it contains data and code that will be freed
2806                  * after the module is initialized.
2807                  */
2808                 kmemleak_ignore(ptr);
2809                 if (!ptr) {
2810                         module_free(mod, mod->module_core);
2811                         return -ENOMEM;
2812                 }
2813                 memset(ptr, 0, mod->init_size);
2814                 mod->module_init = ptr;
2815         } else
2816                 mod->module_init = NULL;
2817 
2818         /* Transfer each section which specifies SHF_ALLOC */
2819         pr_debug("final section addresses:\n");
2820         for (i = 0; i < info->hdr->e_shnum; i++) {
2821                 void *dest;
2822                 Elf_Shdr *shdr = &info->sechdrs[i];
2823 
2824                 if (!(shdr->sh_flags & SHF_ALLOC))
2825                         continue;
2826 
2827                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2828                         dest = mod->module_init
2829                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2830                 else
2831                         dest = mod->module_core + shdr->sh_entsize;
2832 
2833                 if (shdr->sh_type != SHT_NOBITS)
2834                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2835                 /* Update sh_addr to point to copy in image. */
2836                 shdr->sh_addr = (unsigned long)dest;
2837                 pr_debug("\t0x%lx %s\n",
2838                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2839         }
2840 
2841         return 0;
2842 }
2843 
2844 static int check_module_license_and_versions(struct module *mod)
2845 {
2846         /*
2847          * ndiswrapper is under GPL by itself, but loads proprietary modules.
2848          * Don't use add_taint_module(), as it would prevent ndiswrapper from
2849          * using GPL-only symbols it needs.
2850          */
2851         if (strcmp(mod->name, "ndiswrapper") == 0)
2852                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2853 
2854         /* driverloader was caught wrongly pretending to be under GPL */
2855         if (strcmp(mod->name, "driverloader") == 0)
2856                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2857                                  LOCKDEP_NOW_UNRELIABLE);
2858 
2859         /* lve claims to be GPL but upstream won't provide source */
2860         if (strcmp(mod->name, "lve") == 0)
2861                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2862                                  LOCKDEP_NOW_UNRELIABLE);
2863 
2864 #ifdef CONFIG_MODVERSIONS
2865         if ((mod->num_syms && !mod->crcs)
2866             || (mod->num_gpl_syms && !mod->gpl_crcs)
2867             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2868 #ifdef CONFIG_UNUSED_SYMBOLS
2869             || (mod->num_unused_syms && !mod->unused_crcs)
2870             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2871 #endif
2872                 ) {
2873                 return try_to_force_load(mod,
2874                                          "no versions for exported symbols");
2875         }
2876 #endif
2877         return 0;
2878 }
2879 
2880 static void flush_module_icache(const struct module *mod)
2881 {
2882         mm_segment_t old_fs;
2883 
2884         /* flush the icache in correct context */
2885         old_fs = get_fs();
2886         set_fs(KERNEL_DS);
2887 
2888         /*
2889          * Flush the instruction cache, since we've played with text.
2890          * Do it before processing of module parameters, so the module
2891          * can provide parameter accessor functions of its own.
2892          */
2893         if (mod->module_init)
2894                 flush_icache_range((unsigned long)mod->module_init,
2895                                    (unsigned long)mod->module_init
2896                                    + mod->init_size);
2897         flush_icache_range((unsigned long)mod->module_core,
2898                            (unsigned long)mod->module_core + mod->core_size);
2899 
2900         set_fs(old_fs);
2901 }
2902 
2903 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2904                                      Elf_Shdr *sechdrs,
2905                                      char *secstrings,
2906                                      struct module *mod)
2907 {
2908         return 0;
2909 }
2910 
2911 static struct module *layout_and_allocate(struct load_info *info, int flags)
2912 {
2913         /* Module within temporary copy. */
2914         struct module *mod;
2915         int err;
2916 
2917         mod = setup_load_info(info, flags);
2918         if (IS_ERR(mod))
2919                 return mod;
2920 
2921         err = check_modinfo(mod, info, flags);
2922         if (err)
2923                 return ERR_PTR(err);
2924 
2925         /* Allow arches to frob section contents and sizes.  */
2926         err = module_frob_arch_sections(info->hdr, info->sechdrs,
2927                                         info->secstrings, mod);
2928         if (err < 0)
2929                 return ERR_PTR(err);
2930 
2931         /* We will do a special allocation for per-cpu sections later. */
2932         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2933 
2934         /* Determine total sizes, and put offsets in sh_entsize.  For now
2935            this is done generically; there doesn't appear to be any
2936            special cases for the architectures. */
2937         layout_sections(mod, info);
2938         layout_symtab(mod, info);
2939 
2940         /* Allocate and move to the final place */
2941         err = move_module(mod, info);
2942         if (err)
2943                 return ERR_PTR(err);
2944 
2945         /* Module has been copied to its final place now: return it. */
2946         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2947         kmemleak_load_module(mod, info);
2948         return mod;
2949 }
2950 
2951 /* mod is no longer valid after this! */
2952 static void module_deallocate(struct module *mod, struct load_info *info)
2953 {
2954         percpu_modfree(mod);
2955         module_free(mod, mod->module_init);
2956         module_free(mod, mod->module_core);
2957 }
2958 
2959 int __weak module_finalize(const Elf_Ehdr *hdr,
2960                            const Elf_Shdr *sechdrs,
2961                            struct module *me)
2962 {
2963         return 0;
2964 }
2965 
2966 static int post_relocation(struct module *mod, const struct load_info *info)
2967 {
2968         /* Sort exception table now relocations are done. */
2969         sort_extable(mod->extable, mod->extable + mod->num_exentries);
2970 
2971         /* Copy relocated percpu area over. */
2972         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2973                        info->sechdrs[info->index.pcpu].sh_size);
2974 
2975         /* Setup kallsyms-specific fields. */
2976         add_kallsyms(mod, info);
2977 
2978         /* Arch-specific module finalizing. */
2979         return module_finalize(info->hdr, info->sechdrs, mod);
2980 }
2981 
2982 /* Is this module of this name done loading?  No locks held. */
2983 static bool finished_loading(const char *name)
2984 {
2985         struct module *mod;
2986         bool ret;
2987 
2988         mutex_lock(&module_mutex);
2989         mod = find_module_all(name, strlen(name), true);
2990         ret = !mod || mod->state == MODULE_STATE_LIVE
2991                 || mod->state == MODULE_STATE_GOING;
2992         mutex_unlock(&module_mutex);
2993 
2994         return ret;
2995 }
2996 
2997 /* Call module constructors. */
2998 static void do_mod_ctors(struct module *mod)
2999 {
3000 #ifdef CONFIG_CONSTRUCTORS
3001         unsigned long i;
3002 
3003         for (i = 0; i < mod->num_ctors; i++)
3004                 mod->ctors[i]();
3005 #endif
3006 }
3007 
3008 /* This is where the real work happens */
3009 static int do_init_module(struct module *mod)
3010 {
3011         int ret = 0;
3012 
3013         /*
3014          * We want to find out whether @mod uses async during init.  Clear
3015          * PF_USED_ASYNC.  async_schedule*() will set it.
3016          */
3017         current->flags &= ~PF_USED_ASYNC;
3018 
3019         do_mod_ctors(mod);
3020         /* Start the module */
3021         if (mod->init != NULL)
3022                 ret = do_one_initcall(mod->init);
3023         if (ret < 0) {
3024                 /* Init routine failed: abort.  Try to protect us from
3025                    buggy refcounters. */
3026                 mod->state = MODULE_STATE_GOING;
3027                 synchronize_sched();
3028                 module_put(mod);
3029                 blocking_notifier_call_chain(&module_notify_list,
3030                                              MODULE_STATE_GOING, mod);
3031                 free_module(mod);
3032                 wake_up_all(&module_wq);
3033                 return ret;
3034         }
3035         if (ret > 0) {
3036                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3037                         "follow 0/-E convention\n"
3038                         "%s: loading module anyway...\n",
3039                         __func__, mod->name, ret, __func__);
3040                 dump_stack();
3041         }
3042 
3043         /* Now it's a first class citizen! */
3044         mod->state = MODULE_STATE_LIVE;
3045         blocking_notifier_call_chain(&module_notify_list,
3046                                      MODULE_STATE_LIVE, mod);
3047 
3048         /*
3049          * We need to finish all async code before the module init sequence
3050          * is done.  This has potential to deadlock.  For example, a newly
3051          * detected block device can trigger request_module() of the
3052          * default iosched from async probing task.  Once userland helper
3053          * reaches here, async_synchronize_full() will wait on the async
3054          * task waiting on request_module() and deadlock.
3055          *
3056          * This deadlock is avoided by perfomring async_synchronize_full()
3057          * iff module init queued any async jobs.  This isn't a full
3058          * solution as it will deadlock the same if module loading from
3059          * async jobs nests more than once; however, due to the various
3060          * constraints, this hack seems to be the best option for now.
3061          * Please refer to the following thread for details.
3062          *
3063          * http://thread.gmane.org/gmane.linux.kernel/1420814
3064          */
3065         if (current->flags & PF_USED_ASYNC)
3066                 async_synchronize_full();
3067 
3068         mutex_lock(&module_mutex);
3069         /* Drop initial reference. */
3070         module_put(mod);
3071         trim_init_extable(mod);
3072 #ifdef CONFIG_KALLSYMS
3073         mod->num_symtab = mod->core_num_syms;
3074         mod->symtab = mod->core_symtab;
3075         mod->strtab = mod->core_strtab;
3076 #endif
3077         unset_module_init_ro_nx(mod);
3078         module_free(mod, mod->module_init);
3079         mod->module_init = NULL;
3080         mod->init_size = 0;
3081         mod->init_ro_size = 0;
3082         mod->init_text_size = 0;
3083         mutex_unlock(&module_mutex);
3084         wake_up_all(&module_wq);
3085 
3086         return 0;
3087 }
3088 
3089 static int may_init_module(void)
3090 {
3091         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3092                 return -EPERM;
3093 
3094         return 0;
3095 }
3096 
3097 /*
3098  * We try to place it in the list now to make sure it's unique before
3099  * we dedicate too many resources.  In particular, temporary percpu
3100  * memory exhaustion.
3101  */
3102 static int add_unformed_module(struct module *mod)
3103 {
3104         int err;
3105         struct module *old;
3106 
3107         mod->state = MODULE_STATE_UNFORMED;
3108 
3109 again:
3110         mutex_lock(&module_mutex);
3111         old = find_module_all(mod->name, strlen(mod->name), true);
3112         if (old != NULL) {
3113                 if (old->state == MODULE_STATE_COMING
3114                     || old->state == MODULE_STATE_UNFORMED) {
3115                         /* Wait in case it fails to load. */
3116                         mutex_unlock(&module_mutex);
3117                         err = wait_event_interruptible(module_wq,
3118                                                finished_loading(mod->name));
3119                         if (err)
3120                                 goto out_unlocked;
3121                         goto again;
3122                 }
3123                 err = -EEXIST;
3124                 goto out;
3125         }
3126         list_add_rcu(&mod->list, &modules);
3127         err = 0;
3128 
3129 out:
3130         mutex_unlock(&module_mutex);
3131 out_unlocked:
3132         return err;
3133 }
3134 
3135 static int complete_formation(struct module *mod, struct load_info *info)
3136 {
3137         int err;
3138 
3139         mutex_lock(&module_mutex);
3140 
3141         /* Find duplicate symbols (must be called under lock). */
3142         err = verify_export_symbols(mod);
3143         if (err < 0)
3144                 goto out;
3145 
3146         /* This relies on module_mutex for list integrity. */
3147         module_bug_finalize(info->hdr, info->sechdrs, mod);
3148 
3149         /* Set RO and NX regions for core */
3150         set_section_ro_nx(mod->module_core,
3151                                 mod->core_text_size,
3152                                 mod->core_ro_size,
3153                                 mod->core_size);
3154 
3155         /* Set RO and NX regions for init */
3156         set_section_ro_nx(mod->module_init,
3157                                 mod->init_text_size,
3158                                 mod->init_ro_size,
3159                                 mod->init_size);
3160 
3161         /* Mark state as coming so strong_try_module_get() ignores us,
3162          * but kallsyms etc. can see us. */
3163         mod->state = MODULE_STATE_COMING;
3164         mutex_unlock(&module_mutex);
3165 
3166         blocking_notifier_call_chain(&module_notify_list,
3167                                      MODULE_STATE_COMING, mod);
3168         return 0;
3169 
3170 out:
3171         mutex_unlock(&module_mutex);
3172         return err;
3173 }
3174 
3175 static int unknown_module_param_cb(char *param, char *val, const char *modname)
3176 {
3177         /* Check for magic 'dyndbg' arg */ 
3178         int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3179         if (ret != 0)
3180                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3181         return 0;
3182 }
3183 
3184 /* Allocate and load the module: note that size of section 0 is always
3185    zero, and we rely on this for optional sections. */
3186 static int load_module(struct load_info *info, const char __user *uargs,
3187                        int flags)
3188 {
3189         struct module *mod;
3190         long err;
3191         char *after_dashes;
3192 
3193         err = module_sig_check(info);
3194         if (err)
3195                 goto free_copy;
3196 
3197         err = elf_header_check(info);
3198         if (err)
3199                 goto free_copy;
3200 
3201         /* Figure out module layout, and allocate all the memory. */
3202         mod = layout_and_allocate(info, flags);
3203         if (IS_ERR(mod)) {
3204                 err = PTR_ERR(mod);
3205                 goto free_copy;
3206         }
3207 
3208         /* Reserve our place in the list. */
3209         err = add_unformed_module(mod);
3210         if (err)
3211                 goto free_module;
3212 
3213 #ifdef CONFIG_MODULE_SIG
3214         mod->sig_ok = info->sig_ok;
3215         if (!mod->sig_ok) {
3216                 pr_notice_once("%s: module verification failed: signature "
3217                                "and/or  required key missing - tainting "
3218                                "kernel\n", mod->name);
3219                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3220         }
3221 #endif
3222 
3223         /* To avoid stressing percpu allocator, do this once we're unique. */
3224         err = percpu_modalloc(mod, info);
3225         if (err)
3226                 goto unlink_mod;
3227 
3228         /* Now module is in final location, initialize linked lists, etc. */
3229         err = module_unload_init(mod);
3230         if (err)
3231                 goto unlink_mod;
3232 
3233         /* Now we've got everything in the final locations, we can
3234          * find optional sections. */
3235         err = find_module_sections(mod, info);
3236         if (err)
3237                 goto free_unload;
3238 
3239         err = check_module_license_and_versions(mod);
3240         if (err)
3241                 goto free_unload;
3242 
3243         /* Set up MODINFO_ATTR fields */
3244         setup_modinfo(mod, info);
3245 
3246         /* Fix up syms, so that st_value is a pointer to location. */
3247         err = simplify_symbols(mod, info);
3248         if (err < 0)
3249                 goto free_modinfo;
3250 
3251         err = apply_relocations(mod, info);
3252         if (err < 0)
3253                 goto free_modinfo;
3254 
3255         err = post_relocation(mod, info);
3256         if (err < 0)
3257                 goto free_modinfo;
3258 
3259         flush_module_icache(mod);
3260 
3261         /* Now copy in args */
3262         mod->args = strndup_user(uargs, ~0UL >> 1);
3263         if (IS_ERR(mod->args)) {
3264                 err = PTR_ERR(mod->args);
3265                 goto free_arch_cleanup;
3266         }
3267 
3268         dynamic_debug_setup(info->debug, info->num_debug);
3269 
3270         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3271         ftrace_module_init(mod);
3272 
3273         /* Finally it's fully formed, ready to start executing. */
3274         err = complete_formation(mod, info);
3275         if (err)
3276                 goto ddebug_cleanup;
3277 
3278         /* Module is ready to execute: parsing args may do that. */
3279         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3280                                   -32768, 32767, unknown_module_param_cb);
3281         if (IS_ERR(after_dashes)) {
3282                 err = PTR_ERR(after_dashes);
3283                 goto bug_cleanup;
3284         } else if (after_dashes) {
3285                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3286                        mod->name, after_dashes);
3287         }
3288 
3289         /* Link in to syfs. */
3290         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3291         if (err < 0)
3292                 goto bug_cleanup;
3293 
3294         /* Get rid of temporary copy. */
3295         free_copy(info);
3296 
3297         /* Done! */
3298         trace_module_load(mod);
3299 
3300         return do_init_module(mod);
3301 
3302  bug_cleanup:
3303         /* module_bug_cleanup needs module_mutex protection */
3304         mutex_lock(&module_mutex);
3305         module_bug_cleanup(mod);
3306         mutex_unlock(&module_mutex);
3307 
3308         /* we can't deallocate the module until we clear memory protection */
3309         unset_module_init_ro_nx(mod);
3310         unset_module_core_ro_nx(mod);
3311 
3312  ddebug_cleanup:
3313         dynamic_debug_remove(info->debug);
3314         synchronize_sched();
3315         kfree(mod->args);
3316  free_arch_cleanup:
3317         module_arch_cleanup(mod);
3318  free_modinfo:
3319         free_modinfo(mod);
3320  free_unload:
3321         module_unload_free(mod);
3322  unlink_mod:
3323         mutex_lock(&module_mutex);
3324         /* Unlink carefully: kallsyms could be walking list. */
3325         list_del_rcu(&mod->list);
3326         wake_up_all(&module_wq);
3327         mutex_unlock(&module_mutex);
3328  free_module:
3329         module_deallocate(mod, info);
3330  free_copy:
3331         free_copy(info);
3332         return err;
3333 }
3334 
3335 SYSCALL_DEFINE3(init_module, void __user *, umod,
3336                 unsigned long, len, const char __user *, uargs)
3337 {
3338         int err;
3339         struct load_info info = { };
3340 
3341         err = may_init_module();
3342         if (err)
3343                 return err;
3344 
3345         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3346                umod, len, uargs);
3347 
3348         err = copy_module_from_user(umod, len, &info);
3349         if (err)
3350                 return err;
3351 
3352         return load_module(&info, uargs, 0);
3353 }
3354 
3355 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3356 {
3357         int err;
3358         struct load_info info = { };
3359 
3360         err = may_init_module();
3361         if (err)
3362                 return err;
3363 
3364         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3365 
3366         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3367                       |MODULE_INIT_IGNORE_VERMAGIC))
3368                 return -EINVAL;
3369 
3370         err = copy_module_from_fd(fd, &info);
3371         if (err)
3372                 return err;
3373 
3374         return load_module(&info, uargs, flags);
3375 }
3376 
3377 static inline int within(unsigned long addr, void *start, unsigned long size)
3378 {
3379         return ((void *)addr >= start && (void *)addr < start + size);
3380 }
3381 
3382 #ifdef CONFIG_KALLSYMS
3383 /*
3384  * This ignores the intensely annoying "mapping symbols" found
3385  * in ARM ELF files: $a, $t and $d.
3386  */
3387 static inline int is_arm_mapping_symbol(const char *str)
3388 {
3389         if (str[0] == '.' && str[1] == 'L')
3390                 return true;
3391         return str[0] == '$' && strchr("atd", str[1])
3392                && (str[2] == '\0' || str[2] == '.');
3393 }
3394 
3395 static const char *get_ksymbol(struct module *mod,
3396                                unsigned long addr,
3397                                unsigned long *size,
3398                                unsigned long *offset)
3399 {
3400         unsigned int i, best = 0;
3401         unsigned long nextval;
3402 
3403         /* At worse, next value is at end of module */
3404         if (within_module_init(addr, mod))
3405                 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3406         else
3407                 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3408 
3409         /* Scan for closest preceding symbol, and next symbol. (ELF
3410            starts real symbols at 1). */
3411         for (i = 1; i < mod->num_symtab; i++) {
3412                 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3413                         continue;
3414 
3415                 /* We ignore unnamed symbols: they're uninformative
3416                  * and inserted at a whim. */
3417                 if (mod->symtab[i].st_value <= addr
3418                     && mod->symtab[i].st_value > mod->symtab[best].st_value
3419                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3420                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3421                         best = i;
3422                 if (mod->symtab[i].st_value > addr
3423                     && mod->symtab[i].st_value < nextval
3424                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3425                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3426                         nextval = mod->symtab[i].st_value;
3427         }
3428 
3429         if (!best)
3430                 return NULL;
3431 
3432         if (size)
3433                 *size = nextval - mod->symtab[best].st_value;
3434         if (offset)
3435                 *offset = addr - mod->symtab[best].st_value;
3436         return mod->strtab + mod->symtab[best].st_name;
3437 }
3438 
3439 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3440  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3441 const char *module_address_lookup(unsigned long addr,
3442                             unsigned long *size,
3443                             unsigned long *offset,
3444                             char **modname,
3445                             char *namebuf)
3446 {
3447         struct module *mod;
3448         const char *ret = NULL;
3449 
3450         preempt_disable();
3451         list_for_each_entry_rcu(mod, &modules, list) {
3452                 if (mod->state == MODULE_STATE_UNFORMED)
3453                         continue;
3454                 if (within_module(addr, mod)) {
3455                         if (modname)
3456                                 *modname = mod->name;
3457                         ret = get_ksymbol(mod, addr, size, offset);
3458                         break;
3459                 }
3460         }
3461         /* Make a copy in here where it's safe */
3462         if (ret) {
3463                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3464                 ret = namebuf;
3465         }
3466         preempt_enable();
3467         return ret;
3468 }
3469 
3470 int lookup_module_symbol_name(unsigned long addr, char *symname)
3471 {
3472         struct module *mod;
3473 
3474         preempt_disable();
3475         list_for_each_entry_rcu(mod, &modules, list) {
3476                 if (mod->state == MODULE_STATE_UNFORMED)
3477                         continue;
3478                 if (within_module(addr, mod)) {
3479                         const char *sym;
3480 
3481                         sym = get_ksymbol(mod, addr, NULL, NULL);
3482                         if (!sym)
3483                                 goto out;
3484                         strlcpy(symname, sym, KSYM_NAME_LEN);
3485                         preempt_enable();
3486                         return 0;
3487                 }
3488         }
3489 out:
3490         preempt_enable();
3491         return -ERANGE;
3492 }
3493 
3494 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3495                         unsigned long *offset, char *modname, char *name)
3496 {
3497         struct module *mod;
3498 
3499         preempt_disable();
3500         list_for_each_entry_rcu(mod, &modules, list) {
3501                 if (mod->state == MODULE_STATE_UNFORMED)
3502                         continue;
3503                 if (within_module(addr, mod)) {
3504                         const char *sym;
3505 
3506                         sym = get_ksymbol(mod, addr, size, offset);
3507                         if (!sym)
3508                                 goto out;
3509                         if (modname)
3510                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3511                         if (name)
3512                                 strlcpy(name, sym, KSYM_NAME_LEN);
3513                         preempt_enable();
3514                         return 0;
3515                 }
3516         }
3517 out:
3518         preempt_enable();
3519         return -ERANGE;
3520 }
3521 
3522 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3523                         char *name, char *module_name, int *exported)
3524 {
3525         struct module *mod;
3526 
3527         preempt_disable();
3528         list_for_each_entry_rcu(mod, &modules, list) {
3529                 if (mod->state == MODULE_STATE_UNFORMED)
3530                         continue;
3531                 if (symnum < mod->num_symtab) {
3532                         *value = mod->symtab[symnum].st_value;
3533                         *type = mod->symtab[symnum].st_info;
3534                         strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3535                                 KSYM_NAME_LEN);
3536                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3537                         *exported = is_exported(name, *value, mod);
3538                         preempt_enable();
3539                         return 0;
3540                 }
3541                 symnum -= mod->num_symtab;
3542         }
3543         preempt_enable();
3544         return -ERANGE;
3545 }
3546 
3547 static unsigned long mod_find_symname(struct module *mod, const char *name)
3548 {
3549         unsigned int i;
3550 
3551         for (i = 0; i < mod->num_symtab; i++)
3552                 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3553                     mod->symtab[i].st_info != 'U')
3554                         return mod->symtab[i].st_value;
3555         return 0;
3556 }
3557 
3558 /* Look for this name: can be of form module:name. */
3559 unsigned long module_kallsyms_lookup_name(const char *name)
3560 {
3561         struct module *mod;
3562         char *colon;
3563         unsigned long ret = 0;
3564 
3565         /* Don't lock: we're in enough trouble already. */
3566         preempt_disable();
3567         if ((colon = strchr(name, ':')) != NULL) {
3568                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3569                         ret = mod_find_symname(mod, colon+1);
3570         } else {
3571                 list_for_each_entry_rcu(mod, &modules, list) {
3572                         if (mod->state == MODULE_STATE_UNFORMED)
3573                                 continue;
3574                         if ((ret = mod_find_symname(mod, name)) != 0)
3575                                 break;
3576                 }
3577         }
3578         preempt_enable();
3579         return ret;
3580 }
3581 
3582 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3583                                              struct module *, unsigned long),
3584                                    void *data)
3585 {
3586         struct module *mod;
3587         unsigned int i;
3588         int ret;
3589 
3590         list_for_each_entry(mod, &modules, list) {
3591                 if (mod->state == MODULE_STATE_UNFORMED)
3592                         continue;
3593                 for (i = 0; i < mod->num_symtab; i++) {
3594                         ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3595                                  mod, mod->symtab[i].st_value);
3596                         if (ret != 0)
3597                                 return ret;
3598                 }
3599         }
3600         return 0;
3601 }
3602 #endif /* CONFIG_KALLSYMS */
3603 
3604 static char *module_flags(struct module *mod, char *buf)
3605 {
3606         int bx = 0;
3607 
3608         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3609         if (mod->taints ||
3610             mod->state == MODULE_STATE_GOING ||
3611             mod->state == MODULE_STATE_COMING) {
3612                 buf[bx++] = '(';
3613                 bx += module_flags_taint(mod, buf + bx);
3614                 /* Show a - for module-is-being-unloaded */
3615                 if (mod->state == MODULE_STATE_GOING)
3616                         buf[bx++] = '-';
3617                 /* Show a + for module-is-being-loaded */
3618                 if (mod->state == MODULE_STATE_COMING)
3619                         buf[bx++] = '+';
3620                 buf[bx++] = ')';
3621         }
3622         buf[bx] = '\0';
3623 
3624         return buf;
3625 }
3626 
3627 #ifdef CONFIG_PROC_FS
3628 /* Called by the /proc file system to return a list of modules. */
3629 static void *m_start(struct seq_file *m, loff_t *pos)
3630 {
3631         mutex_lock(&module_mutex);
3632         return seq_list_start(&modules, *pos);
3633 }
3634 
3635 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3636 {
3637         return seq_list_next(p, &modules, pos);
3638 }
3639 
3640 static void m_stop(struct seq_file *m, void *p)
3641 {
3642         mutex_unlock(&module_mutex);
3643 }
3644 
3645 static int m_show(struct seq_file *m, void *p)
3646 {
3647         struct module *mod = list_entry(p, struct module, list);
3648         char buf[8];
3649 
3650         /* We always ignore unformed modules. */
3651         if (mod->state == MODULE_STATE_UNFORMED)
3652                 return 0;
3653 
3654         seq_printf(m, "%s %u",
3655                    mod->name, mod->init_size + mod->core_size);
3656         print_unload_info(m, mod);
3657 
3658         /* Informative for users. */
3659         seq_printf(m, " %s",
3660                    mod->state == MODULE_STATE_GOING ? "Unloading":
3661                    mod->state == MODULE_STATE_COMING ? "Loading":
3662                    "Live");
3663         /* Used by oprofile and other similar tools. */
3664         seq_printf(m, " 0x%pK", mod->module_core);
3665 
3666         /* Taints info */
3667         if (mod->taints)
3668                 seq_printf(m, " %s", module_flags(mod, buf));
3669 
3670         seq_printf(m, "\n");
3671         return 0;
3672 }
3673 
3674 /* Format: modulename size refcount deps address
3675 
3676    Where refcount is a number or -, and deps is a comma-separated list
3677    of depends or -.
3678 */
3679 static const struct seq_operations modules_op = {
3680         .start  = m_start,
3681         .next   = m_next,
3682         .stop   = m_stop,
3683         .show   = m_show
3684 };
3685 
3686 static int modules_open(struct inode *inode, struct file *file)
3687 {
3688         return seq_open(file, &modules_op);
3689 }
3690 
3691 static const struct file_operations proc_modules_operations = {
3692         .open           = modules_open,
3693         .read           = seq_read,
3694         .llseek         = seq_lseek,
3695         .release        = seq_release,
3696 };
3697 
3698 static int __init proc_modules_init(void)
3699 {
3700         proc_create("modules", 0, NULL, &proc_modules_operations);
3701         return 0;
3702 }
3703 module_init(proc_modules_init);
3704 #endif
3705 
3706 /* Given an address, look for it in the module exception tables. */
3707 const struct exception_table_entry *search_module_extables(unsigned long addr)
3708 {
3709         const struct exception_table_entry *e = NULL;
3710         struct module *mod;
3711 
3712         preempt_disable();
3713         list_for_each_entry_rcu(mod, &modules, list) {
3714                 if (mod->state == MODULE_STATE_UNFORMED)
3715                         continue;
3716                 if (mod->num_exentries == 0)
3717                         continue;
3718 
3719                 e = search_extable(mod->extable,
3720                                    mod->extable + mod->num_exentries - 1,
3721                                    addr);
3722                 if (e)
3723                         break;
3724         }
3725         preempt_enable();
3726 
3727         /* Now, if we found one, we are running inside it now, hence
3728            we cannot unload the module, hence no refcnt needed. */
3729         return e;
3730 }
3731 
3732 /*
3733  * is_module_address - is this address inside a module?
3734  * @addr: the address to check.
3735  *
3736  * See is_module_text_address() if you simply want to see if the address
3737  * is code (not data).
3738  */
3739 bool is_module_address(unsigned long addr)
3740 {
3741         bool ret;
3742 
3743         preempt_disable();
3744         ret = __module_address(addr) != NULL;
3745         preempt_enable();
3746 
3747         return ret;
3748 }
3749 
3750 /*
3751  * __module_address - get the module which contains an address.
3752  * @addr: the address.
3753  *
3754  * Must be called with preempt disabled or module mutex held so that
3755  * module doesn't get freed during this.
3756  */
3757 struct module *__module_address(unsigned long addr)
3758 {
3759         struct module *mod;
3760 
3761         if (addr < module_addr_min || addr > module_addr_max)
3762                 return NULL;
3763 
3764         list_for_each_entry_rcu(mod, &modules, list) {
3765                 if (mod->state == MODULE_STATE_UNFORMED)
3766                         continue;
3767                 if (within_module(addr, mod))
3768                         return mod;
3769         }
3770         return NULL;
3771 }
3772 EXPORT_SYMBOL_GPL(__module_address);
3773 
3774 /*
3775  * is_module_text_address - is this address inside module code?
3776  * @addr: the address to check.
3777  *
3778  * See is_module_address() if you simply want to see if the address is
3779  * anywhere in a module.  See kernel_text_address() for testing if an
3780  * address corresponds to kernel or module code.
3781  */
3782 bool is_module_text_address(unsigned long addr)
3783 {
3784         bool ret;
3785 
3786         preempt_disable();
3787         ret = __module_text_address(addr) != NULL;
3788         preempt_enable();
3789 
3790         return ret;
3791 }
3792 
3793 /*
3794  * __module_text_address - get the module whose code contains an address.
3795  * @addr: the address.
3796  *
3797  * Must be called with preempt disabled or module mutex held so that
3798  * module doesn't get freed during this.
3799  */
3800 struct module *__module_text_address(unsigned long addr)
3801 {
3802         struct module *mod = __module_address(addr);
3803         if (mod) {
3804                 /* Make sure it's within the text section. */
3805                 if (!within(addr, mod->module_init, mod->init_text_size)
3806                     && !within(addr, mod->module_core, mod->core_text_size))
3807                         mod = NULL;
3808         }
3809         return mod;
3810 }
3811 EXPORT_SYMBOL_GPL(__module_text_address);
3812 
3813 /* Don't grab lock, we're oopsing. */
3814 void print_modules(void)
3815 {
3816         struct module *mod;
3817         char buf[8];
3818 
3819         printk(KERN_DEFAULT "Modules linked in:");
3820         /* Most callers should already have preempt disabled, but make sure */
3821         preempt_disable();
3822         list_for_each_entry_rcu(mod, &modules, list) {
3823                 if (mod->state == MODULE_STATE_UNFORMED)
3824                         continue;
3825                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
3826         }
3827         preempt_enable();
3828         if (last_unloaded_module[0])
3829                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
3830         pr_cont("\n");
3831 }
3832 
3833 #ifdef CONFIG_MODVERSIONS
3834 /* Generate the signature for all relevant module structures here.
3835  * If these change, we don't want to try to parse the module. */
3836 void module_layout(struct module *mod,
3837                    struct modversion_info *ver,
3838                    struct kernel_param *kp,
3839                    struct kernel_symbol *ks,
3840                    struct tracepoint * const *tp)
3841 {
3842 }
3843 EXPORT_SYMBOL(module_layout);
3844 #endif
3845 

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