linux/kernel/module.c
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   1/*
   2   Copyright (C) 2002 Richard Henderson
   3   Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18*/
  19#include <linux/export.h>
  20#include <linux/moduleloader.h>
  21#include <linux/ftrace_event.h>
  22#include <linux/init.h>
  23#include <linux/kallsyms.h>
  24#include <linux/file.h>
  25#include <linux/fs.h>
  26#include <linux/sysfs.h>
  27#include <linux/kernel.h>
  28#include <linux/slab.h>
  29#include <linux/vmalloc.h>
  30#include <linux/elf.h>
  31#include <linux/proc_fs.h>
  32#include <linux/security.h>
  33#include <linux/seq_file.h>
  34#include <linux/syscalls.h>
  35#include <linux/fcntl.h>
  36#include <linux/rcupdate.h>
  37#include <linux/capability.h>
  38#include <linux/cpu.h>
  39#include <linux/moduleparam.h>
  40#include <linux/errno.h>
  41#include <linux/err.h>
  42#include <linux/vermagic.h>
  43#include <linux/notifier.h>
  44#include <linux/sched.h>
  45#include <linux/stop_machine.h>
  46#include <linux/device.h>
  47#include <linux/string.h>
  48#include <linux/mutex.h>
  49#include <linux/rculist.h>
  50#include <asm/uaccess.h>
  51#include <asm/cacheflush.h>
  52#include <asm/mmu_context.h>
  53#include <linux/license.h>
  54#include <asm/sections.h>
  55#include <linux/tracepoint.h>
  56#include <linux/ftrace.h>
  57#include <linux/async.h>
  58#include <linux/percpu.h>
  59#include <linux/kmemleak.h>
  60#include <linux/jump_label.h>
  61#include <linux/pfn.h>
  62#include <linux/bsearch.h>
  63#include <linux/fips.h>
  64#include <uapi/linux/module.h>
  65#include "module-internal.h"
  66
  67#define CREATE_TRACE_POINTS
  68#include <trace/events/module.h>
  69
  70#ifndef ARCH_SHF_SMALL
  71#define ARCH_SHF_SMALL 0
  72#endif
  73
  74/*
  75 * Modules' sections will be aligned on page boundaries
  76 * to ensure complete separation of code and data, but
  77 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
  78 */
  79#ifdef CONFIG_DEBUG_SET_MODULE_RONX
  80# define debug_align(X) ALIGN(X, PAGE_SIZE)
  81#else
  82# define debug_align(X) (X)
  83#endif
  84
  85/*
  86 * Given BASE and SIZE this macro calculates the number of pages the
  87 * memory regions occupies
  88 */
  89#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?         \
  90                (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
  91                         PFN_DOWN((unsigned long)BASE) + 1)     \
  92                : (0UL))
  93
  94/* If this is set, the section belongs in the init part of the module */
  95#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
  96
  97/*
  98 * Mutex protects:
  99 * 1) List of modules (also safely readable with preempt_disable),
 100 * 2) module_use links,
 101 * 3) module_addr_min/module_addr_max.
 102 * (delete uses stop_machine/add uses RCU list operations). */
 103DEFINE_MUTEX(module_mutex);
 104EXPORT_SYMBOL_GPL(module_mutex);
 105static LIST_HEAD(modules);
 106#ifdef CONFIG_KGDB_KDB
 107struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
 108#endif /* CONFIG_KGDB_KDB */
 109
 110#ifdef CONFIG_MODULE_SIG
 111#ifdef CONFIG_MODULE_SIG_FORCE
 112static bool sig_enforce = true;
 113#else
 114static bool sig_enforce = false;
 115
 116static int param_set_bool_enable_only(const char *val,
 117                                      const struct kernel_param *kp)
 118{
 119        int err;
 120        bool test;
 121        struct kernel_param dummy_kp = *kp;
 122
 123        dummy_kp.arg = &test;
 124
 125        err = param_set_bool(val, &dummy_kp);
 126        if (err)
 127                return err;
 128
 129        /* Don't let them unset it once it's set! */
 130        if (!test && sig_enforce)
 131                return -EROFS;
 132
 133        if (test)
 134                sig_enforce = true;
 135        return 0;
 136}
 137
 138static const struct kernel_param_ops param_ops_bool_enable_only = {
 139        .set = param_set_bool_enable_only,
 140        .get = param_get_bool,
 141};
 142#define param_check_bool_enable_only param_check_bool
 143
 144module_param(sig_enforce, bool_enable_only, 0644);
 145#endif /* !CONFIG_MODULE_SIG_FORCE */
 146#endif /* CONFIG_MODULE_SIG */
 147
 148/* Block module loading/unloading? */
 149int modules_disabled = 0;
 150core_param(nomodule, modules_disabled, bint, 0);
 151
 152/* Waiting for a module to finish initializing? */
 153static DECLARE_WAIT_QUEUE_HEAD(module_wq);
 154
 155static BLOCKING_NOTIFIER_HEAD(module_notify_list);
 156
 157/* Bounds of module allocation, for speeding __module_address.
 158 * Protected by module_mutex. */
 159static unsigned long module_addr_min = -1UL, module_addr_max = 0;
 160
 161int register_module_notifier(struct notifier_block * nb)
 162{
 163        return blocking_notifier_chain_register(&module_notify_list, nb);
 164}
 165EXPORT_SYMBOL(register_module_notifier);
 166
 167int unregister_module_notifier(struct notifier_block * nb)
 168{
 169        return blocking_notifier_chain_unregister(&module_notify_list, nb);
 170}
 171EXPORT_SYMBOL(unregister_module_notifier);
 172
 173struct 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. */
 189static 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
 200static 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 */
 211void __module_put_and_exit(struct module *mod, long code)
 212{
 213        module_put(mod);
 214        do_exit(code);
 215}
 216EXPORT_SYMBOL(__module_put_and_exit);
 217
 218/* Find a module section: 0 means not found. */
 219static 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. */
 234static 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. */
 241static 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 */
 254extern const struct kernel_symbol __start___ksymtab[];
 255extern const struct kernel_symbol __stop___ksymtab[];
 256extern const struct kernel_symbol __start___ksymtab_gpl[];
 257extern const struct kernel_symbol __stop___ksymtab_gpl[];
 258extern const struct kernel_symbol __start___ksymtab_gpl_future[];
 259extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
 260extern const unsigned long __start___kcrctab[];
 261extern const unsigned long __start___kcrctab_gpl[];
 262extern const unsigned long __start___kcrctab_gpl_future[];
 263#ifdef CONFIG_UNUSED_SYMBOLS
 264extern const struct kernel_symbol __start___ksymtab_unused[];
 265extern const struct kernel_symbol __stop___ksymtab_unused[];
 266extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
 267extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
 268extern const unsigned long __start___kcrctab_unused[];
 269extern 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
 278static 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. */
 297bool 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}
 356EXPORT_SYMBOL_GPL(each_symbol_section);
 357
 358struct 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
 370static 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                        printk(KERN_WARNING "Symbol %s is being used "
 381                               "by a non-GPL module, which will not "
 382                               "be allowed in the future\n", fsa->name);
 383                }
 384        }
 385
 386#ifdef CONFIG_UNUSED_SYMBOLS
 387        if (syms->unused && fsa->warn) {
 388                printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
 389                       "however this module is using it.\n", fsa->name);
 390                printk(KERN_WARNING
 391                       "This symbol will go away in the future.\n");
 392                printk(KERN_WARNING
 393                       "Please evalute if this is the right api to use and if "
 394                       "it really is, submit a report the linux kernel "
 395                       "mailinglist together with submitting your code for "
 396                       "inclusion.\n");
 397        }
 398#endif
 399
 400        fsa->owner = owner;
 401        fsa->crc = symversion(syms->crcs, symnum);
 402        fsa->sym = &syms->start[symnum];
 403        return true;
 404}
 405
 406static int cmp_name(const void *va, const void *vb)
 407{
 408        const char *a;
 409        const struct kernel_symbol *b;
 410        a = va; b = vb;
 411        return strcmp(a, b->name);
 412}
 413
 414static bool find_symbol_in_section(const struct symsearch *syms,
 415                                   struct module *owner,
 416                                   void *data)
 417{
 418        struct find_symbol_arg *fsa = data;
 419        struct kernel_symbol *sym;
 420
 421        sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
 422                        sizeof(struct kernel_symbol), cmp_name);
 423
 424        if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
 425                return true;
 426
 427        return false;
 428}
 429
 430/* Find a symbol and return it, along with, (optional) crc and
 431 * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
 432const struct kernel_symbol *find_symbol(const char *name,
 433                                        struct module **owner,
 434                                        const unsigned long **crc,
 435                                        bool gplok,
 436                                        bool warn)
 437{
 438        struct find_symbol_arg fsa;
 439
 440        fsa.name = name;
 441        fsa.gplok = gplok;
 442        fsa.warn = warn;
 443
 444        if (each_symbol_section(find_symbol_in_section, &fsa)) {
 445                if (owner)
 446                        *owner = fsa.owner;
 447                if (crc)
 448                        *crc = fsa.crc;
 449                return fsa.sym;
 450        }
 451
 452        pr_debug("Failed to find symbol %s\n", name);
 453        return NULL;
 454}
 455EXPORT_SYMBOL_GPL(find_symbol);
 456
 457/* Search for module by name: must hold module_mutex. */
 458static struct module *find_module_all(const char *name, size_t len,
 459                                      bool even_unformed)
 460{
 461        struct module *mod;
 462
 463        list_for_each_entry(mod, &modules, list) {
 464                if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
 465                        continue;
 466                if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
 467                        return mod;
 468        }
 469        return NULL;
 470}
 471
 472struct module *find_module(const char *name)
 473{
 474        return find_module_all(name, strlen(name), false);
 475}
 476EXPORT_SYMBOL_GPL(find_module);
 477
 478#ifdef CONFIG_SMP
 479
 480static inline void __percpu *mod_percpu(struct module *mod)
 481{
 482        return mod->percpu;
 483}
 484
 485static int percpu_modalloc(struct module *mod, struct load_info *info)
 486{
 487        Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
 488        unsigned long align = pcpusec->sh_addralign;
 489
 490        if (!pcpusec->sh_size)
 491                return 0;
 492
 493        if (align > PAGE_SIZE) {
 494                printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
 495                       mod->name, align, PAGE_SIZE);
 496                align = PAGE_SIZE;
 497        }
 498
 499        mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
 500        if (!mod->percpu) {
 501                printk(KERN_WARNING
 502                       "%s: Could not allocate %lu bytes percpu data\n",
 503                       mod->name, (unsigned long)pcpusec->sh_size);
 504                return -ENOMEM;
 505        }
 506        mod->percpu_size = pcpusec->sh_size;
 507        return 0;
 508}
 509
 510static void percpu_modfree(struct module *mod)
 511{
 512        free_percpu(mod->percpu);
 513}
 514
 515static unsigned int find_pcpusec(struct load_info *info)
 516{
 517        return find_sec(info, ".data..percpu");
 518}
 519
 520static void percpu_modcopy(struct module *mod,
 521                           const void *from, unsigned long size)
 522{
 523        int cpu;
 524
 525        for_each_possible_cpu(cpu)
 526                memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
 527}
 528
 529/**
 530 * is_module_percpu_address - test whether address is from module static percpu
 531 * @addr: address to test
 532 *
 533 * Test whether @addr belongs to module static percpu area.
 534 *
 535 * RETURNS:
 536 * %true if @addr is from module static percpu area
 537 */
 538bool is_module_percpu_address(unsigned long addr)
 539{
 540        struct module *mod;
 541        unsigned int cpu;
 542
 543        preempt_disable();
 544
 545        list_for_each_entry_rcu(mod, &modules, list) {
 546                if (mod->state == MODULE_STATE_UNFORMED)
 547                        continue;
 548                if (!mod->percpu_size)
 549                        continue;
 550                for_each_possible_cpu(cpu) {
 551                        void *start = per_cpu_ptr(mod->percpu, cpu);
 552
 553                        if ((void *)addr >= start &&
 554                            (void *)addr < start + mod->percpu_size) {
 555                                preempt_enable();
 556                                return true;
 557                        }
 558                }
 559        }
 560
 561        preempt_enable();
 562        return false;
 563}
 564
 565#else /* ... !CONFIG_SMP */
 566
 567static inline void __percpu *mod_percpu(struct module *mod)
 568{
 569        return NULL;
 570}
 571static int percpu_modalloc(struct module *mod, struct load_info *info)
 572{
 573        /* UP modules shouldn't have this section: ENOMEM isn't quite right */
 574        if (info->sechdrs[info->index.pcpu].sh_size != 0)
 575                return -ENOMEM;
 576        return 0;
 577}
 578static inline void percpu_modfree(struct module *mod)
 579{
 580}
 581static unsigned int find_pcpusec(struct load_info *info)
 582{
 583        return 0;
 584}
 585static inline void percpu_modcopy(struct module *mod,
 586                                  const void *from, unsigned long size)
 587{
 588        /* pcpusec should be 0, and size of that section should be 0. */
 589        BUG_ON(size != 0);
 590}
 591bool is_module_percpu_address(unsigned long addr)
 592{
 593        return false;
 594}
 595
 596#endif /* CONFIG_SMP */
 597
 598#define MODINFO_ATTR(field)     \
 599static void setup_modinfo_##field(struct module *mod, const char *s)  \
 600{                                                                     \
 601        mod->field = kstrdup(s, GFP_KERNEL);                          \
 602}                                                                     \
 603static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
 604                        struct module_kobject *mk, char *buffer)      \
 605{                                                                     \
 606        return sprintf(buffer, "%s\n", mk->mod->field);               \
 607}                                                                     \
 608static int modinfo_##field##_exists(struct module *mod)               \
 609{                                                                     \
 610        return mod->field != NULL;                                    \
 611}                                                                     \
 612static void free_modinfo_##field(struct module *mod)                  \
 613{                                                                     \
 614        kfree(mod->field);                                            \
 615        mod->field = NULL;                                            \
 616}                                                                     \
 617static struct module_attribute modinfo_##field = {                    \
 618        .attr = { .name = __stringify(field), .mode = 0444 },         \
 619        .show = show_modinfo_##field,                                 \
 620        .setup = setup_modinfo_##field,                               \
 621        .test = modinfo_##field##_exists,                             \
 622        .free = free_modinfo_##field,                                 \
 623};
 624
 625MODINFO_ATTR(version);
 626MODINFO_ATTR(srcversion);
 627
 628static char last_unloaded_module[MODULE_NAME_LEN+1];
 629
 630#ifdef CONFIG_MODULE_UNLOAD
 631
 632EXPORT_TRACEPOINT_SYMBOL(module_get);
 633
 634/* Init the unload section of the module. */
 635static int module_unload_init(struct module *mod)
 636{
 637        mod->refptr = alloc_percpu(struct module_ref);
 638        if (!mod->refptr)
 639                return -ENOMEM;
 640
 641        INIT_LIST_HEAD(&mod->source_list);
 642        INIT_LIST_HEAD(&mod->target_list);
 643
 644        /* Hold reference count during initialization. */
 645        __this_cpu_write(mod->refptr->incs, 1);
 646        /* Backwards compatibility macros put refcount during init. */
 647        mod->waiter = current;
 648
 649        return 0;
 650}
 651
 652/* Does a already use b? */
 653static int already_uses(struct module *a, struct module *b)
 654{
 655        struct module_use *use;
 656
 657        list_for_each_entry(use, &b->source_list, source_list) {
 658                if (use->source == a) {
 659                        pr_debug("%s uses %s!\n", a->name, b->name);
 660                        return 1;
 661                }
 662        }
 663        pr_debug("%s does not use %s!\n", a->name, b->name);
 664        return 0;
 665}
 666
 667/*
 668 * Module a uses b
 669 *  - we add 'a' as a "source", 'b' as a "target" of module use
 670 *  - the module_use is added to the list of 'b' sources (so
 671 *    'b' can walk the list to see who sourced them), and of 'a'
 672 *    targets (so 'a' can see what modules it targets).
 673 */
 674static int add_module_usage(struct module *a, struct module *b)
 675{
 676        struct module_use *use;
 677
 678        pr_debug("Allocating new usage for %s.\n", a->name);
 679        use = kmalloc(sizeof(*use), GFP_ATOMIC);
 680        if (!use) {
 681                printk(KERN_WARNING "%s: out of memory loading\n", a->name);
 682                return -ENOMEM;
 683        }
 684
 685        use->source = a;
 686        use->target = b;
 687        list_add(&use->source_list, &b->source_list);
 688        list_add(&use->target_list, &a->target_list);
 689        return 0;
 690}
 691
 692/* Module a uses b: caller needs module_mutex() */
 693int ref_module(struct module *a, struct module *b)
 694{
 695        int err;
 696
 697        if (b == NULL || already_uses(a, b))
 698                return 0;
 699
 700        /* If module isn't available, we fail. */
 701        err = strong_try_module_get(b);
 702        if (err)
 703                return err;
 704
 705        err = add_module_usage(a, b);
 706        if (err) {
 707                module_put(b);
 708                return err;
 709        }
 710        return 0;
 711}
 712EXPORT_SYMBOL_GPL(ref_module);
 713
 714/* Clear the unload stuff of the module. */
 715static void module_unload_free(struct module *mod)
 716{
 717        struct module_use *use, *tmp;
 718
 719        mutex_lock(&module_mutex);
 720        list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
 721                struct module *i = use->target;
 722                pr_debug("%s unusing %s\n", mod->name, i->name);
 723                module_put(i);
 724                list_del(&use->source_list);
 725                list_del(&use->target_list);
 726                kfree(use);
 727        }
 728        mutex_unlock(&module_mutex);
 729
 730        free_percpu(mod->refptr);
 731}
 732
 733#ifdef CONFIG_MODULE_FORCE_UNLOAD
 734static inline int try_force_unload(unsigned int flags)
 735{
 736        int ret = (flags & O_TRUNC);
 737        if (ret)
 738                add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
 739        return ret;
 740}
 741#else
 742static inline int try_force_unload(unsigned int flags)
 743{
 744        return 0;
 745}
 746#endif /* CONFIG_MODULE_FORCE_UNLOAD */
 747
 748struct stopref
 749{
 750        struct module *mod;
 751        int flags;
 752        int *forced;
 753};
 754
 755/* Whole machine is stopped with interrupts off when this runs. */
 756static int __try_stop_module(void *_sref)
 757{
 758        struct stopref *sref = _sref;
 759
 760        /* If it's not unused, quit unless we're forcing. */
 761        if (module_refcount(sref->mod) != 0) {
 762                if (!(*sref->forced = try_force_unload(sref->flags)))
 763                        return -EWOULDBLOCK;
 764        }
 765
 766        /* Mark it as dying. */
 767        sref->mod->state = MODULE_STATE_GOING;
 768        return 0;
 769}
 770
 771static int try_stop_module(struct module *mod, int flags, int *forced)
 772{
 773        if (flags & O_NONBLOCK) {
 774                struct stopref sref = { mod, flags, forced };
 775
 776                return stop_machine(__try_stop_module, &sref, NULL);
 777        } else {
 778                /* We don't need to stop the machine for this. */
 779                mod->state = MODULE_STATE_GOING;
 780                synchronize_sched();
 781                return 0;
 782        }
 783}
 784
 785unsigned long module_refcount(struct module *mod)
 786{
 787        unsigned long incs = 0, decs = 0;
 788        int cpu;
 789
 790        for_each_possible_cpu(cpu)
 791                decs += per_cpu_ptr(mod->refptr, cpu)->decs;
 792        /*
 793         * ensure the incs are added up after the decs.
 794         * module_put ensures incs are visible before decs with smp_wmb.
 795         *
 796         * This 2-count scheme avoids the situation where the refcount
 797         * for CPU0 is read, then CPU0 increments the module refcount,
 798         * then CPU1 drops that refcount, then the refcount for CPU1 is
 799         * read. We would record a decrement but not its corresponding
 800         * increment so we would see a low count (disaster).
 801         *
 802         * Rare situation? But module_refcount can be preempted, and we
 803         * might be tallying up 4096+ CPUs. So it is not impossible.
 804         */
 805        smp_rmb();
 806        for_each_possible_cpu(cpu)
 807                incs += per_cpu_ptr(mod->refptr, cpu)->incs;
 808        return incs - decs;
 809}
 810EXPORT_SYMBOL(module_refcount);
 811
 812/* This exists whether we can unload or not */
 813static void free_module(struct module *mod);
 814
 815static void wait_for_zero_refcount(struct module *mod)
 816{
 817        /* Since we might sleep for some time, release the mutex first */
 818        mutex_unlock(&module_mutex);
 819        for (;;) {
 820                pr_debug("Looking at refcount...\n");
 821                set_current_state(TASK_UNINTERRUPTIBLE);
 822                if (module_refcount(mod) == 0)
 823                        break;
 824                schedule();
 825        }
 826        current->state = TASK_RUNNING;
 827        mutex_lock(&module_mutex);
 828}
 829
 830SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
 831                unsigned int, flags)
 832{
 833        struct module *mod;
 834        char name[MODULE_NAME_LEN];
 835        int ret, forced = 0;
 836
 837        if (!capable(CAP_SYS_MODULE) || modules_disabled)
 838                return -EPERM;
 839
 840        if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
 841                return -EFAULT;
 842        name[MODULE_NAME_LEN-1] = '\0';
 843
 844        if (mutex_lock_interruptible(&module_mutex) != 0)
 845                return -EINTR;
 846
 847        mod = find_module(name);
 848        if (!mod) {
 849                ret = -ENOENT;
 850                goto out;
 851        }
 852
 853        if (!list_empty(&mod->source_list)) {
 854                /* Other modules depend on us: get rid of them first. */
 855                ret = -EWOULDBLOCK;
 856                goto out;
 857        }
 858
 859        /* Doing init or already dying? */
 860        if (mod->state != MODULE_STATE_LIVE) {
 861                /* FIXME: if (force), slam module count and wake up
 862                   waiter --RR */
 863                pr_debug("%s already dying\n", mod->name);
 864                ret = -EBUSY;
 865                goto out;
 866        }
 867
 868        /* If it has an init func, it must have an exit func to unload */
 869        if (mod->init && !mod->exit) {
 870                forced = try_force_unload(flags);
 871                if (!forced) {
 872                        /* This module can't be removed */
 873                        ret = -EBUSY;
 874                        goto out;
 875                }
 876        }
 877
 878        /* Set this up before setting mod->state */
 879        mod->waiter = current;
 880
 881        /* Stop the machine so refcounts can't move and disable module. */
 882        ret = try_stop_module(mod, flags, &forced);
 883        if (ret != 0)
 884                goto out;
 885
 886        /* Never wait if forced. */
 887        if (!forced && module_refcount(mod) != 0)
 888                wait_for_zero_refcount(mod);
 889
 890        mutex_unlock(&module_mutex);
 891        /* Final destruction now no one is using it. */
 892        if (mod->exit != NULL)
 893                mod->exit();
 894        blocking_notifier_call_chain(&module_notify_list,
 895                                     MODULE_STATE_GOING, mod);
 896        async_synchronize_full();
 897
 898        /* Store the name of the last unloaded module for diagnostic purposes */
 899        strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
 900
 901        free_module(mod);
 902        return 0;
 903out:
 904        mutex_unlock(&module_mutex);
 905        return ret;
 906}
 907
 908static inline void print_unload_info(struct seq_file *m, struct module *mod)
 909{
 910        struct module_use *use;
 911        int printed_something = 0;
 912
 913        seq_printf(m, " %lu ", module_refcount(mod));
 914
 915        /* Always include a trailing , so userspace can differentiate
 916           between this and the old multi-field proc format. */
 917        list_for_each_entry(use, &mod->source_list, source_list) {
 918                printed_something = 1;
 919                seq_printf(m, "%s,", use->source->name);
 920        }
 921
 922        if (mod->init != NULL && mod->exit == NULL) {
 923                printed_something = 1;
 924                seq_printf(m, "[permanent],");
 925        }
 926
 927        if (!printed_something)
 928                seq_printf(m, "-");
 929}
 930
 931void __symbol_put(const char *symbol)
 932{
 933        struct module *owner;
 934
 935        preempt_disable();
 936        if (!find_symbol(symbol, &owner, NULL, true, false))
 937                BUG();
 938        module_put(owner);
 939        preempt_enable();
 940}
 941EXPORT_SYMBOL(__symbol_put);
 942
 943/* Note this assumes addr is a function, which it currently always is. */
 944void symbol_put_addr(void *addr)
 945{
 946        struct module *modaddr;
 947        unsigned long a = (unsigned long)dereference_function_descriptor(addr);
 948
 949        if (core_kernel_text(a))
 950                return;
 951
 952        /* module_text_address is safe here: we're supposed to have reference
 953         * to module from symbol_get, so it can't go away. */
 954        modaddr = __module_text_address(a);
 955        BUG_ON(!modaddr);
 956        module_put(modaddr);
 957}
 958EXPORT_SYMBOL_GPL(symbol_put_addr);
 959
 960static ssize_t show_refcnt(struct module_attribute *mattr,
 961                           struct module_kobject *mk, char *buffer)
 962{
 963        return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
 964}
 965
 966static struct module_attribute modinfo_refcnt =
 967        __ATTR(refcnt, 0444, show_refcnt, NULL);
 968
 969void __module_get(struct module *module)
 970{
 971        if (module) {
 972                preempt_disable();
 973                __this_cpu_inc(module->refptr->incs);
 974                trace_module_get(module, _RET_IP_);
 975                preempt_enable();
 976        }
 977}
 978EXPORT_SYMBOL(__module_get);
 979
 980bool try_module_get(struct module *module)
 981{
 982        bool ret = true;
 983
 984        if (module) {
 985                preempt_disable();
 986
 987                if (likely(module_is_live(module))) {
 988                        __this_cpu_inc(module->refptr->incs);
 989                        trace_module_get(module, _RET_IP_);
 990                } else
 991                        ret = false;
 992
 993                preempt_enable();
 994        }
 995        return ret;
 996}
 997EXPORT_SYMBOL(try_module_get);
 998
 999void module_put(struct module *module)
1000{
1001        if (module) {
1002                preempt_disable();
1003                smp_wmb(); /* see comment in module_refcount */
1004                __this_cpu_inc(module->refptr->decs);
1005
1006                trace_module_put(module, _RET_IP_);
1007                /* Maybe they're waiting for us to drop reference? */
1008                if (unlikely(!module_is_live(module)))
1009                        wake_up_process(module->waiter);
1010                preempt_enable();
1011        }
1012}
1013EXPORT_SYMBOL(module_put);
1014
1015#else /* !CONFIG_MODULE_UNLOAD */
1016static inline void print_unload_info(struct seq_file *m, struct module *mod)
1017{
1018        /* We don't know the usage count, or what modules are using. */
1019        seq_printf(m, " - -");
1020}
1021
1022static inline void module_unload_free(struct module *mod)
1023{
1024}
1025
1026int ref_module(struct module *a, struct module *b)
1027{
1028        return strong_try_module_get(b);
1029}
1030EXPORT_SYMBOL_GPL(ref_module);
1031
1032static inline int module_unload_init(struct module *mod)
1033{
1034        return 0;
1035}
1036#endif /* CONFIG_MODULE_UNLOAD */
1037
1038static size_t module_flags_taint(struct module *mod, char *buf)
1039{
1040        size_t l = 0;
1041
1042        if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1043                buf[l++] = 'P';
1044        if (mod->taints & (1 << TAINT_OOT_MODULE))
1045                buf[l++] = 'O';
1046        if (mod->taints & (1 << TAINT_FORCED_MODULE))
1047                buf[l++] = 'F';
1048        if (mod->taints & (1 << TAINT_CRAP))
1049                buf[l++] = 'C';
1050        /*
1051         * TAINT_FORCED_RMMOD: could be added.
1052         * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1053         * apply to modules.
1054         */
1055        return l;
1056}
1057
1058static ssize_t show_initstate(struct module_attribute *mattr,
1059                              struct module_kobject *mk, char *buffer)
1060{
1061        const char *state = "unknown";
1062
1063        switch (mk->mod->state) {
1064        case MODULE_STATE_LIVE:
1065                state = "live";
1066                break;
1067        case MODULE_STATE_COMING:
1068                state = "coming";
1069                break;
1070        case MODULE_STATE_GOING:
1071                state = "going";
1072                break;
1073        default:
1074                BUG();
1075        }
1076        return sprintf(buffer, "%s\n", state);
1077}
1078
1079static struct module_attribute modinfo_initstate =
1080        __ATTR(initstate, 0444, show_initstate, NULL);
1081
1082static ssize_t store_uevent(struct module_attribute *mattr,
1083                            struct module_kobject *mk,
1084                            const char *buffer, size_t count)
1085{
1086        enum kobject_action action;
1087
1088        if (kobject_action_type(buffer, count, &action) == 0)
1089                kobject_uevent(&mk->kobj, action);
1090        return count;
1091}
1092
1093struct module_attribute module_uevent =
1094        __ATTR(uevent, 0200, NULL, store_uevent);
1095
1096static ssize_t show_coresize(struct module_attribute *mattr,
1097                             struct module_kobject *mk, char *buffer)
1098{
1099        return sprintf(buffer, "%u\n", mk->mod->core_size);
1100}
1101
1102static struct module_attribute modinfo_coresize =
1103        __ATTR(coresize, 0444, show_coresize, NULL);
1104
1105static ssize_t show_initsize(struct module_attribute *mattr,
1106                             struct module_kobject *mk, char *buffer)
1107{
1108        return sprintf(buffer, "%u\n", mk->mod->init_size);
1109}
1110
1111static struct module_attribute modinfo_initsize =
1112        __ATTR(initsize, 0444, show_initsize, NULL);
1113
1114static ssize_t show_taint(struct module_attribute *mattr,
1115                          struct module_kobject *mk, char *buffer)
1116{
1117        size_t l;
1118
1119        l = module_flags_taint(mk->mod, buffer);
1120        buffer[l++] = '\n';
1121        return l;
1122}
1123
1124static struct module_attribute modinfo_taint =
1125        __ATTR(taint, 0444, show_taint, NULL);
1126
1127static struct module_attribute *modinfo_attrs[] = {
1128        &module_uevent,
1129        &modinfo_version,
1130        &modinfo_srcversion,
1131        &modinfo_initstate,
1132        &modinfo_coresize,
1133        &modinfo_initsize,
1134        &modinfo_taint,
1135#ifdef CONFIG_MODULE_UNLOAD
1136        &modinfo_refcnt,
1137#endif
1138        NULL,
1139};
1140
1141static const char vermagic[] = VERMAGIC_STRING;
1142
1143static int try_to_force_load(struct module *mod, const char *reason)
1144{
1145#ifdef CONFIG_MODULE_FORCE_LOAD
1146        if (!test_taint(TAINT_FORCED_MODULE))
1147                printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1148                       mod->name, reason);
1149        add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1150        return 0;
1151#else
1152        return -ENOEXEC;
1153#endif
1154}
1155
1156#ifdef CONFIG_MODVERSIONS
1157/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1158static unsigned long maybe_relocated(unsigned long crc,
1159                                     const struct module *crc_owner)
1160{
1161#ifdef ARCH_RELOCATES_KCRCTAB
1162        if (crc_owner == NULL)
1163                return crc - (unsigned long)reloc_start;
1164#endif
1165        return crc;
1166}
1167
1168static int check_version(Elf_Shdr *sechdrs,
1169                         unsigned int versindex,
1170                         const char *symname,
1171                         struct module *mod, 
1172                         const unsigned long *crc,
1173                         const struct module *crc_owner)
1174{
1175        unsigned int i, num_versions;
1176        struct modversion_info *versions;
1177
1178        /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1179        if (!crc)
1180                return 1;
1181
1182        /* No versions at all?  modprobe --force does this. */
1183        if (versindex == 0)
1184                return try_to_force_load(mod, symname) == 0;
1185
1186        versions = (void *) sechdrs[versindex].sh_addr;
1187        num_versions = sechdrs[versindex].sh_size
1188                / sizeof(struct modversion_info);
1189
1190        for (i = 0; i < num_versions; i++) {
1191                if (strcmp(versions[i].name, symname) != 0)
1192                        continue;
1193
1194                if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1195                        return 1;
1196                pr_debug("Found checksum %lX vs module %lX\n",
1197                       maybe_relocated(*crc, crc_owner), versions[i].crc);
1198                goto bad_version;
1199        }
1200
1201        printk(KERN_WARNING "%s: no symbol version for %s\n",
1202               mod->name, symname);
1203        return 0;
1204
1205bad_version:
1206        printk("%s: disagrees about version of symbol %s\n",
1207               mod->name, symname);
1208        return 0;
1209}
1210
1211static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1212                                          unsigned int versindex,
1213                                          struct module *mod)
1214{
1215        const unsigned long *crc;
1216
1217        /* Since this should be found in kernel (which can't be removed),
1218         * no locking is necessary. */
1219        if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1220                         &crc, true, false))
1221                BUG();
1222        return check_version(sechdrs, versindex,
1223                             VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1224                             NULL);
1225}
1226
1227/* First part is kernel version, which we ignore if module has crcs. */
1228static inline int same_magic(const char *amagic, const char *bmagic,
1229                             bool has_crcs)
1230{
1231        if (has_crcs) {
1232                amagic += strcspn(amagic, " ");
1233                bmagic += strcspn(bmagic, " ");
1234        }
1235        return strcmp(amagic, bmagic) == 0;
1236}
1237#else
1238static inline int check_version(Elf_Shdr *sechdrs,
1239                                unsigned int versindex,
1240                                const char *symname,
1241                                struct module *mod, 
1242                                const unsigned long *crc,
1243                                const struct module *crc_owner)
1244{
1245        return 1;
1246}
1247
1248static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1249                                          unsigned int versindex,
1250                                          struct module *mod)
1251{
1252        return 1;
1253}
1254
1255static inline int same_magic(const char *amagic, const char *bmagic,
1256                             bool has_crcs)
1257{
1258        return strcmp(amagic, bmagic) == 0;
1259}
1260#endif /* CONFIG_MODVERSIONS */
1261
1262/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1263static const struct kernel_symbol *resolve_symbol(struct module *mod,
1264                                                  const struct load_info *info,
1265                                                  const char *name,
1266                                                  char ownername[])
1267{
1268        struct module *owner;
1269        const struct kernel_symbol *sym;
1270        const unsigned long *crc;
1271        int err;
1272
1273        mutex_lock(&module_mutex);
1274        sym = find_symbol(name, &owner, &crc,
1275                          !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1276        if (!sym)
1277                goto unlock;
1278
1279        if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1280                           owner)) {
1281                sym = ERR_PTR(-EINVAL);
1282                goto getname;
1283        }
1284
1285        err = ref_module(mod, owner);
1286        if (err) {
1287                sym = ERR_PTR(err);
1288                goto getname;
1289        }
1290
1291getname:
1292        /* We must make copy under the lock if we failed to get ref. */
1293        strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1294unlock:
1295        mutex_unlock(&module_mutex);
1296        return sym;
1297}
1298
1299static const struct kernel_symbol *
1300resolve_symbol_wait(struct module *mod,
1301                    const struct load_info *info,
1302                    const char *name)
1303{
1304        const struct kernel_symbol *ksym;
1305        char owner[MODULE_NAME_LEN];
1306
1307        if (wait_event_interruptible_timeout(module_wq,
1308                        !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1309                        || PTR_ERR(ksym) != -EBUSY,
1310                                             30 * HZ) <= 0) {
1311                printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1312                       mod->name, owner);
1313        }
1314        return ksym;
1315}
1316
1317/*
1318 * /sys/module/foo/sections stuff
1319 * J. Corbet <corbet@lwn.net>
1320 */
1321#ifdef CONFIG_SYSFS
1322
1323#ifdef CONFIG_KALLSYMS
1324static inline bool sect_empty(const Elf_Shdr *sect)
1325{
1326        return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1327}
1328
1329struct module_sect_attr
1330{
1331        struct module_attribute mattr;
1332        char *name;
1333        unsigned long address;
1334};
1335
1336struct module_sect_attrs
1337{
1338        struct attribute_group grp;
1339        unsigned int nsections;
1340        struct module_sect_attr attrs[0];
1341};
1342
1343static ssize_t module_sect_show(struct module_attribute *mattr,
1344                                struct module_kobject *mk, char *buf)
1345{
1346        struct module_sect_attr *sattr =
1347                container_of(mattr, struct module_sect_attr, mattr);
1348        return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1349}
1350
1351static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1352{
1353        unsigned int section;
1354
1355        for (section = 0; section < sect_attrs->nsections; section++)
1356                kfree(sect_attrs->attrs[section].name);
1357        kfree(sect_attrs);
1358}
1359
1360static void add_sect_attrs(struct module *mod, const struct load_info *info)
1361{
1362        unsigned int nloaded = 0, i, size[2];
1363        struct module_sect_attrs *sect_attrs;
1364        struct module_sect_attr *sattr;
1365        struct attribute **gattr;
1366
1367        /* Count loaded sections and allocate structures */
1368        for (i = 0; i < info->hdr->e_shnum; i++)
1369                if (!sect_empty(&info->sechdrs[i]))
1370                        nloaded++;
1371        size[0] = ALIGN(sizeof(*sect_attrs)
1372                        + nloaded * sizeof(sect_attrs->attrs[0]),
1373                        sizeof(sect_attrs->grp.attrs[0]));
1374        size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1375        sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1376        if (sect_attrs == NULL)
1377                return;
1378
1379        /* Setup section attributes. */
1380        sect_attrs->grp.name = "sections";
1381        sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1382
1383        sect_attrs->nsections = 0;
1384        sattr = &sect_attrs->attrs[0];
1385        gattr = &sect_attrs->grp.attrs[0];
1386        for (i = 0; i < info->hdr->e_shnum; i++) {
1387                Elf_Shdr *sec = &info->sechdrs[i];
1388                if (sect_empty(sec))
1389                        continue;
1390                sattr->address = sec->sh_addr;
1391                sattr->name = kstrdup(info->secstrings + sec->sh_name,
1392                                        GFP_KERNEL);
1393                if (sattr->name == NULL)
1394                        goto out;
1395                sect_attrs->nsections++;
1396                sysfs_attr_init(&sattr->mattr.attr);
1397                sattr->mattr.show = module_sect_show;
1398                sattr->mattr.store = NULL;
1399                sattr->mattr.attr.name = sattr->name;
1400                sattr->mattr.attr.mode = S_IRUGO;
1401                *(gattr++) = &(sattr++)->mattr.attr;
1402        }
1403        *gattr = NULL;
1404
1405        if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1406                goto out;
1407
1408        mod->sect_attrs = sect_attrs;
1409        return;
1410  out:
1411        free_sect_attrs(sect_attrs);
1412}
1413
1414static void remove_sect_attrs(struct module *mod)
1415{
1416        if (mod->sect_attrs) {
1417                sysfs_remove_group(&mod->mkobj.kobj,
1418                                   &mod->sect_attrs->grp);
1419                /* We are positive that no one is using any sect attrs
1420                 * at this point.  Deallocate immediately. */
1421                free_sect_attrs(mod->sect_attrs);
1422                mod->sect_attrs = NULL;
1423        }
1424}
1425
1426/*
1427 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1428 */
1429
1430struct module_notes_attrs {
1431        struct kobject *dir;
1432        unsigned int notes;
1433        struct bin_attribute attrs[0];
1434};
1435
1436static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1437                                 struct bin_attribute *bin_attr,
1438                                 char *buf, loff_t pos, size_t count)
1439{
1440        /*
1441         * The caller checked the pos and count against our size.
1442         */
1443        memcpy(buf, bin_attr->private + pos, count);
1444        return count;
1445}
1446
1447static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1448                             unsigned int i)
1449{
1450        if (notes_attrs->dir) {
1451                while (i-- > 0)
1452                        sysfs_remove_bin_file(notes_attrs->dir,
1453                                              &notes_attrs->attrs[i]);
1454                kobject_put(notes_attrs->dir);
1455        }
1456        kfree(notes_attrs);
1457}
1458
1459static void add_notes_attrs(struct module *mod, const struct load_info *info)
1460{
1461        unsigned int notes, loaded, i;
1462        struct module_notes_attrs *notes_attrs;
1463        struct bin_attribute *nattr;
1464
1465        /* failed to create section attributes, so can't create notes */
1466        if (!mod->sect_attrs)
1467                return;
1468
1469        /* Count notes sections and allocate structures.  */
1470        notes = 0;
1471        for (i = 0; i < info->hdr->e_shnum; i++)
1472                if (!sect_empty(&info->sechdrs[i]) &&
1473                    (info->sechdrs[i].sh_type == SHT_NOTE))
1474                        ++notes;
1475
1476        if (notes == 0)
1477                return;
1478
1479        notes_attrs = kzalloc(sizeof(*notes_attrs)
1480                              + notes * sizeof(notes_attrs->attrs[0]),
1481                              GFP_KERNEL);
1482        if (notes_attrs == NULL)
1483                return;
1484
1485        notes_attrs->notes = notes;
1486        nattr = &notes_attrs->attrs[0];
1487        for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1488                if (sect_empty(&info->sechdrs[i]))
1489                        continue;
1490                if (info->sechdrs[i].sh_type == SHT_NOTE) {
1491                        sysfs_bin_attr_init(nattr);
1492                        nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1493                        nattr->attr.mode = S_IRUGO;
1494                        nattr->size = info->sechdrs[i].sh_size;
1495                        nattr->private = (void *) info->sechdrs[i].sh_addr;
1496                        nattr->read = module_notes_read;
1497                        ++nattr;
1498                }
1499                ++loaded;
1500        }
1501
1502        notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1503        if (!notes_attrs->dir)
1504                goto out;
1505
1506        for (i = 0; i < notes; ++i)
1507                if (sysfs_create_bin_file(notes_attrs->dir,
1508                                          &notes_attrs->attrs[i]))
1509                        goto out;
1510
1511        mod->notes_attrs = notes_attrs;
1512        return;
1513
1514  out:
1515        free_notes_attrs(notes_attrs, i);
1516}
1517
1518static void remove_notes_attrs(struct module *mod)
1519{
1520        if (mod->notes_attrs)
1521                free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1522}
1523
1524#else
1525
1526static inline void add_sect_attrs(struct module *mod,
1527                                  const struct load_info *info)
1528{
1529}
1530
1531static inline void remove_sect_attrs(struct module *mod)
1532{
1533}
1534
1535static inline void add_notes_attrs(struct module *mod,
1536                                   const struct load_info *info)
1537{
1538}
1539
1540static inline void remove_notes_attrs(struct module *mod)
1541{
1542}
1543#endif /* CONFIG_KALLSYMS */
1544
1545static void add_usage_links(struct module *mod)
1546{
1547#ifdef CONFIG_MODULE_UNLOAD
1548        struct module_use *use;
1549        int nowarn;
1550
1551        mutex_lock(&module_mutex);
1552        list_for_each_entry(use, &mod->target_list, target_list) {
1553                nowarn = sysfs_create_link(use->target->holders_dir,
1554                                           &mod->mkobj.kobj, mod->name);
1555        }
1556        mutex_unlock(&module_mutex);
1557#endif
1558}
1559
1560static void del_usage_links(struct module *mod)
1561{
1562#ifdef CONFIG_MODULE_UNLOAD
1563        struct module_use *use;
1564
1565        mutex_lock(&module_mutex);
1566        list_for_each_entry(use, &mod->target_list, target_list)
1567                sysfs_remove_link(use->target->holders_dir, mod->name);
1568        mutex_unlock(&module_mutex);
1569#endif
1570}
1571
1572static int module_add_modinfo_attrs(struct module *mod)
1573{
1574        struct module_attribute *attr;
1575        struct module_attribute *temp_attr;
1576        int error = 0;
1577        int i;
1578
1579        mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1580                                        (ARRAY_SIZE(modinfo_attrs) + 1)),
1581                                        GFP_KERNEL);
1582        if (!mod->modinfo_attrs)
1583                return -ENOMEM;
1584
1585        temp_attr = mod->modinfo_attrs;
1586        for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1587                if (!attr->test ||
1588                    (attr->test && attr->test(mod))) {
1589                        memcpy(temp_attr, attr, sizeof(*temp_attr));
1590                        sysfs_attr_init(&temp_attr->attr);
1591                        error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1592                        ++temp_attr;
1593                }
1594        }
1595        return error;
1596}
1597
1598static void module_remove_modinfo_attrs(struct module *mod)
1599{
1600        struct module_attribute *attr;
1601        int i;
1602
1603        for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1604                /* pick a field to test for end of list */
1605                if (!attr->attr.name)
1606                        break;
1607                sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1608                if (attr->free)
1609                        attr->free(mod);
1610        }
1611        kfree(mod->modinfo_attrs);
1612}
1613
1614static int mod_sysfs_init(struct module *mod)
1615{
1616        int err;
1617        struct kobject *kobj;
1618
1619        if (!module_sysfs_initialized) {
1620                printk(KERN_ERR "%s: module sysfs not initialized\n",
1621                       mod->name);
1622                err = -EINVAL;
1623                goto out;
1624        }
1625
1626        kobj = kset_find_obj(module_kset, mod->name);
1627        if (kobj) {
1628                printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1629                kobject_put(kobj);
1630                err = -EINVAL;
1631                goto out;
1632        }
1633
1634        mod->mkobj.mod = mod;
1635
1636        memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1637        mod->mkobj.kobj.kset = module_kset;
1638        err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1639                                   "%s", mod->name);
1640        if (err)
1641                kobject_put(&mod->mkobj.kobj);
1642
1643        /* delay uevent until full sysfs population */
1644out:
1645        return err;
1646}
1647
1648static int mod_sysfs_setup(struct module *mod,
1649                           const struct load_info *info,
1650                           struct kernel_param *kparam,
1651                           unsigned int num_params)
1652{
1653        int err;
1654
1655        err = mod_sysfs_init(mod);
1656        if (err)
1657                goto out;
1658
1659        mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1660        if (!mod->holders_dir) {
1661                err = -ENOMEM;
1662                goto out_unreg;
1663        }
1664
1665        err = module_param_sysfs_setup(mod, kparam, num_params);
1666        if (err)
1667                goto out_unreg_holders;
1668
1669        err = module_add_modinfo_attrs(mod);
1670        if (err)
1671                goto out_unreg_param;
1672
1673        add_usage_links(mod);
1674        add_sect_attrs(mod, info);
1675        add_notes_attrs(mod, info);
1676
1677        kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1678        return 0;
1679
1680out_unreg_param:
1681        module_param_sysfs_remove(mod);
1682out_unreg_holders:
1683        kobject_put(mod->holders_dir);
1684out_unreg:
1685        kobject_put(&mod->mkobj.kobj);
1686out:
1687        return err;
1688}
1689
1690static void mod_sysfs_fini(struct module *mod)
1691{
1692        remove_notes_attrs(mod);
1693        remove_sect_attrs(mod);
1694        kobject_put(&mod->mkobj.kobj);
1695}
1696
1697#else /* !CONFIG_SYSFS */
1698
1699static int mod_sysfs_setup(struct module *mod,
1700                           const struct load_info *info,
1701                           struct kernel_param *kparam,
1702                           unsigned int num_params)
1703{
1704        return 0;
1705}
1706
1707static void mod_sysfs_fini(struct module *mod)
1708{
1709}
1710
1711static void module_remove_modinfo_attrs(struct module *mod)
1712{
1713}
1714
1715static void del_usage_links(struct module *mod)
1716{
1717}
1718
1719#endif /* CONFIG_SYSFS */
1720
1721static void mod_sysfs_teardown(struct module *mod)
1722{
1723        del_usage_links(mod);
1724        module_remove_modinfo_attrs(mod);
1725        module_param_sysfs_remove(mod);
1726        kobject_put(mod->mkobj.drivers_dir);
1727        kobject_put(mod->holders_dir);
1728        mod_sysfs_fini(mod);
1729}
1730
1731/*
1732 * unlink the module with the whole machine is stopped with interrupts off
1733 * - this defends against kallsyms not taking locks
1734 */
1735static int __unlink_module(void *_mod)
1736{
1737        struct module *mod = _mod;
1738        list_del(&mod->list);
1739        module_bug_cleanup(mod);
1740        return 0;
1741}
1742
1743#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1744/*
1745 * LKM RO/NX protection: protect module's text/ro-data
1746 * from modification and any data from execution.
1747 */
1748void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1749{
1750        unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1751        unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1752
1753        if (end_pfn > begin_pfn)
1754                set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1755}
1756
1757static void set_section_ro_nx(void *base,
1758                        unsigned long text_size,
1759                        unsigned long ro_size,
1760                        unsigned long total_size)
1761{
1762        /* begin and end PFNs of the current subsection */
1763        unsigned long begin_pfn;
1764        unsigned long end_pfn;
1765
1766        /*
1767         * Set RO for module text and RO-data:
1768         * - Always protect first page.
1769         * - Do not protect last partial page.
1770         */
1771        if (ro_size > 0)
1772                set_page_attributes(base, base + ro_size, set_memory_ro);
1773
1774        /*
1775         * Set NX permissions for module data:
1776         * - Do not protect first partial page.
1777         * - Always protect last page.
1778         */
1779        if (total_size > text_size) {
1780                begin_pfn = PFN_UP((unsigned long)base + text_size);
1781                end_pfn = PFN_UP((unsigned long)base + total_size);
1782                if (end_pfn > begin_pfn)
1783                        set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1784        }
1785}
1786
1787static void unset_module_core_ro_nx(struct module *mod)
1788{
1789        set_page_attributes(mod->module_core + mod->core_text_size,
1790                mod->module_core + mod->core_size,
1791                set_memory_x);
1792        set_page_attributes(mod->module_core,
1793                mod->module_core + mod->core_ro_size,
1794                set_memory_rw);
1795}
1796
1797static void unset_module_init_ro_nx(struct module *mod)
1798{
1799        set_page_attributes(mod->module_init + mod->init_text_size,
1800                mod->module_init + mod->init_size,
1801                set_memory_x);
1802        set_page_attributes(mod->module_init,
1803                mod->module_init + mod->init_ro_size,
1804                set_memory_rw);
1805}
1806
1807/* Iterate through all modules and set each module's text as RW */
1808void set_all_modules_text_rw(void)
1809{
1810        struct module *mod;
1811
1812        mutex_lock(&module_mutex);
1813        list_for_each_entry_rcu(mod, &modules, list) {
1814                if (mod->state == MODULE_STATE_UNFORMED)
1815                        continue;
1816                if ((mod->module_core) && (mod->core_text_size)) {
1817                        set_page_attributes(mod->module_core,
1818                                                mod->module_core + mod->core_text_size,
1819                                                set_memory_rw);
1820                }
1821                if ((mod->module_init) && (mod->init_text_size)) {
1822                        set_page_attributes(mod->module_init,
1823                                                mod->module_init + mod->init_text_size,
1824                                                set_memory_rw);
1825                }
1826        }
1827        mutex_unlock(&module_mutex);
1828}
1829
1830/* Iterate through all modules and set each module's text as RO */
1831void set_all_modules_text_ro(void)
1832{
1833        struct module *mod;
1834
1835        mutex_lock(&module_mutex);
1836        list_for_each_entry_rcu(mod, &modules, list) {
1837                if (mod->state == MODULE_STATE_UNFORMED)
1838                        continue;
1839                if ((mod->module_core) && (mod->core_text_size)) {
1840                        set_page_attributes(mod->module_core,
1841                                                mod->module_core + mod->core_text_size,
1842                                                set_memory_ro);
1843                }
1844                if ((mod->module_init) && (mod->init_text_size)) {
1845                        set_page_attributes(mod->module_init,
1846                                                mod->module_init + mod->init_text_size,
1847                                                set_memory_ro);
1848                }
1849        }
1850        mutex_unlock(&module_mutex);
1851}
1852#else
1853static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1854static void unset_module_core_ro_nx(struct module *mod) { }
1855static void unset_module_init_ro_nx(struct module *mod) { }
1856#endif
1857
1858void __weak module_free(struct module *mod, void *module_region)
1859{
1860        vfree(module_region);
1861}
1862
1863void __weak module_arch_cleanup(struct module *mod)
1864{
1865}
1866
1867/* Free a module, remove from lists, etc. */
1868static void free_module(struct module *mod)
1869{
1870        trace_module_free(mod);
1871
1872        mod_sysfs_teardown(mod);
1873
1874        /* We leave it in list to prevent duplicate loads, but make sure
1875         * that noone uses it while it's being deconstructed. */
1876        mod->state = MODULE_STATE_UNFORMED;
1877
1878        /* Remove dynamic debug info */
1879        ddebug_remove_module(mod->name);
1880
1881        /* Arch-specific cleanup. */
1882        module_arch_cleanup(mod);
1883
1884        /* Module unload stuff */
1885        module_unload_free(mod);
1886
1887        /* Free any allocated parameters. */
1888        destroy_params(mod->kp, mod->num_kp);
1889
1890        /* Now we can delete it from the lists */
1891        mutex_lock(&module_mutex);
1892        stop_machine(__unlink_module, mod, NULL);
1893        mutex_unlock(&module_mutex);
1894
1895        /* This may be NULL, but that's OK */
1896        unset_module_init_ro_nx(mod);
1897        module_free(mod, mod->module_init);
1898        kfree(mod->args);
1899        percpu_modfree(mod);
1900
1901        /* Free lock-classes: */
1902        lockdep_free_key_range(mod->module_core, mod->core_size);
1903
1904        /* Finally, free the core (containing the module structure) */
1905        unset_module_core_ro_nx(mod);
1906        module_free(mod, mod->module_core);
1907
1908#ifdef CONFIG_MPU
1909        update_protections(current->mm);
1910#endif
1911}
1912
1913void *__symbol_get(const char *symbol)
1914{
1915        struct module *owner;
1916        const struct kernel_symbol *sym;
1917
1918        preempt_disable();
1919        sym = find_symbol(symbol, &owner, NULL, true, true);
1920        if (sym && strong_try_module_get(owner))
1921                sym = NULL;
1922        preempt_enable();
1923
1924        return sym ? (void *)sym->value : NULL;
1925}
1926EXPORT_SYMBOL_GPL(__symbol_get);
1927
1928/*
1929 * Ensure that an exported symbol [global namespace] does not already exist
1930 * in the kernel or in some other module's exported symbol table.
1931 *
1932 * You must hold the module_mutex.
1933 */
1934static int verify_export_symbols(struct module *mod)
1935{
1936        unsigned int i;
1937        struct module *owner;
1938        const struct kernel_symbol *s;
1939        struct {
1940                const struct kernel_symbol *sym;
1941                unsigned int num;
1942        } arr[] = {
1943                { mod->syms, mod->num_syms },
1944                { mod->gpl_syms, mod->num_gpl_syms },
1945                { mod->gpl_future_syms, mod->num_gpl_future_syms },
1946#ifdef CONFIG_UNUSED_SYMBOLS
1947                { mod->unused_syms, mod->num_unused_syms },
1948                { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1949#endif
1950        };
1951
1952        for (i = 0; i < ARRAY_SIZE(arr); i++) {
1953                for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1954                        if (find_symbol(s->name, &owner, NULL, true, false)) {
1955                                printk(KERN_ERR
1956                                       "%s: exports duplicate symbol %s"
1957                                       " (owned by %s)\n",
1958                                       mod->name, s->name, module_name(owner));
1959                                return -ENOEXEC;
1960                        }
1961                }
1962        }
1963        return 0;
1964}
1965
1966/* Change all symbols so that st_value encodes the pointer directly. */
1967static int simplify_symbols(struct module *mod, const struct load_info *info)
1968{
1969        Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1970        Elf_Sym *sym = (void *)symsec->sh_addr;
1971        unsigned long secbase;
1972        unsigned int i;
1973        int ret = 0;
1974        const struct kernel_symbol *ksym;
1975
1976        for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1977                const char *name = info->strtab + sym[i].st_name;
1978
1979                switch (sym[i].st_shndx) {
1980                case SHN_COMMON:
1981                        /* We compiled with -fno-common.  These are not
1982                           supposed to happen.  */
1983                        pr_debug("Common symbol: %s\n", name);
1984                        printk("%s: please compile with -fno-common\n",
1985                               mod->name);
1986                        ret = -ENOEXEC;
1987                        break;
1988
1989                case SHN_ABS:
1990                        /* Don't need to do anything */
1991                        pr_debug("Absolute symbol: 0x%08lx\n",
1992                               (long)sym[i].st_value);
1993                        break;
1994
1995                case SHN_UNDEF:
1996                        ksym = resolve_symbol_wait(mod, info, name);
1997                        /* Ok if resolved.  */
1998                        if (ksym && !IS_ERR(ksym)) {
1999                                sym[i].st_value = ksym->value;
2000                                break;
2001                        }
2002
2003                        /* Ok if weak.  */
2004                        if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2005                                break;
2006
2007                        printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
2008                               mod->name, name, PTR_ERR(ksym));
2009                        ret = PTR_ERR(ksym) ?: -ENOENT;
2010                        break;
2011
2012                default:
2013                        /* Divert to percpu allocation if a percpu var. */
2014                        if (sym[i].st_shndx == info->index.pcpu)
2015                                secbase = (unsigned long)mod_percpu(mod);
2016                        else
2017                                secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2018                        sym[i].st_value += secbase;
2019                        break;
2020                }
2021        }
2022
2023        return ret;
2024}
2025
2026static int apply_relocations(struct module *mod, const struct load_info *info)
2027{
2028        unsigned int i;
2029        int err = 0;
2030
2031        /* Now do relocations. */
2032        for (i = 1; i < info->hdr->e_shnum; i++) {
2033                unsigned int infosec = info->sechdrs[i].sh_info;
2034
2035                /* Not a valid relocation section? */
2036                if (infosec >= info->hdr->e_shnum)
2037                        continue;
2038
2039                /* Don't bother with non-allocated sections */
2040                if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2041                        continue;
2042
2043                if (info->sechdrs[i].sh_type == SHT_REL)
2044                        err = apply_relocate(info->sechdrs, info->strtab,
2045                                             info->index.sym, i, mod);
2046                else if (info->sechdrs[i].sh_type == SHT_RELA)
2047                        err = apply_relocate_add(info->sechdrs, info->strtab,
2048                                                 info->index.sym, i, mod);
2049                if (err < 0)
2050                        break;
2051        }
2052        return err;
2053}
2054
2055/* Additional bytes needed by arch in front of individual sections */
2056unsigned int __weak arch_mod_section_prepend(struct module *mod,
2057                                             unsigned int section)
2058{
2059        /* default implementation just returns zero */
2060        return 0;
2061}
2062
2063/* Update size with this section: return offset. */
2064static long get_offset(struct module *mod, unsigned int *size,
2065                       Elf_Shdr *sechdr, unsigned int section)
2066{
2067        long ret;
2068
2069        *size += arch_mod_section_prepend(mod, section);
2070        ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2071        *size = ret + sechdr->sh_size;
2072        return ret;
2073}
2074
2075/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2076   might -- code, read-only data, read-write data, small data.  Tally
2077   sizes, and place the offsets into sh_entsize fields: high bit means it
2078   belongs in init. */
2079static void layout_sections(struct module *mod, struct load_info *info)
2080{
2081        static unsigned long const masks[][2] = {
2082                /* NOTE: all executable code must be the first section
2083                 * in this array; otherwise modify the text_size
2084                 * finder in the two loops below */
2085                { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2086                { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2087                { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2088                { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2089        };
2090        unsigned int m, i;
2091
2092        for (i = 0; i < info->hdr->e_shnum; i++)
2093                info->sechdrs[i].sh_entsize = ~0UL;
2094
2095        pr_debug("Core section allocation order:\n");
2096        for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2097                for (i = 0; i < info->hdr->e_shnum; ++i) {
2098                        Elf_Shdr *s = &info->sechdrs[i];
2099                        const char *sname = info->secstrings + s->sh_name;
2100
2101                        if ((s->sh_flags & masks[m][0]) != masks[m][0]
2102                            || (s->sh_flags & masks[m][1])
2103                            || s->sh_entsize != ~0UL
2104                            || strstarts(sname, ".init"))
2105                                continue;
2106                        s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2107                        pr_debug("\t%s\n", sname);
2108                }
2109                switch (m) {
2110                case 0: /* executable */
2111                        mod->core_size = debug_align(mod->core_size);
2112                        mod->core_text_size = mod->core_size;
2113                        break;
2114                case 1: /* RO: text and ro-data */
2115                        mod->core_size = debug_align(mod->core_size);
2116                        mod->core_ro_size = mod->core_size;
2117                        break;
2118                case 3: /* whole core */
2119                        mod->core_size = debug_align(mod->core_size);
2120                        break;
2121                }
2122        }
2123
2124        pr_debug("Init section allocation order:\n");
2125        for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2126                for (i = 0; i < info->hdr->e_shnum; ++i) {
2127                        Elf_Shdr *s = &info->sechdrs[i];
2128                        const char *sname = info->secstrings + s->sh_name;
2129
2130                        if ((s->sh_flags & masks[m][0]) != masks[m][0]
2131                            || (s->sh_flags & masks[m][1])
2132                            || s->sh_entsize != ~0UL
2133                            || !strstarts(sname, ".init"))
2134                                continue;
2135                        s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2136                                         | INIT_OFFSET_MASK);
2137                        pr_debug("\t%s\n", sname);
2138                }
2139                switch (m) {
2140                case 0: /* executable */
2141                        mod->init_size = debug_align(mod->init_size);
2142                        mod->init_text_size = mod->init_size;
2143                        break;
2144                case 1: /* RO: text and ro-data */
2145                        mod->init_size = debug_align(mod->init_size);
2146                        mod->init_ro_size = mod->init_size;
2147                        break;
2148                case 3: /* whole init */
2149                        mod->init_size = debug_align(mod->init_size);
2150                        break;
2151                }
2152        }
2153}
2154
2155static void set_license(struct module *mod, const char *license)
2156{
2157        if (!license)
2158                license = "unspecified";
2159
2160        if (!license_is_gpl_compatible(license)) {
2161                if (!test_taint(TAINT_PROPRIETARY_MODULE))
2162                        printk(KERN_WARNING "%s: module license '%s' taints "
2163                                "kernel.\n", mod->name, license);
2164                add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2165                                 LOCKDEP_NOW_UNRELIABLE);
2166        }
2167}
2168
2169/* Parse tag=value strings from .modinfo section */
2170static char *next_string(char *string, unsigned long *secsize)
2171{
2172        /* Skip non-zero chars */
2173        while (string[0]) {
2174                string++;
2175                if ((*secsize)-- <= 1)
2176                        return NULL;
2177        }
2178
2179        /* Skip any zero padding. */
2180        while (!string[0]) {
2181                string++;
2182                if ((*secsize)-- <= 1)
2183                        return NULL;
2184        }
2185        return string;
2186}
2187
2188static char *get_modinfo(struct load_info *info, const char *tag)
2189{
2190        char *p;
2191        unsigned int taglen = strlen(tag);
2192        Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2193        unsigned long size = infosec->sh_size;
2194
2195        for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2196                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2197                        return p + taglen + 1;
2198        }
2199        return NULL;
2200}
2201
2202static void setup_modinfo(struct module *mod, struct load_info *info)
2203{
2204        struct module_attribute *attr;
2205        int i;
2206
2207        for (i = 0; (attr = modinfo_attrs[i]); i++) {
2208                if (attr->setup)
2209                        attr->setup(mod, get_modinfo(info, attr->attr.name));
2210        }
2211}
2212
2213static void free_modinfo(struct module *mod)
2214{
2215        struct module_attribute *attr;
2216        int i;
2217
2218        for (i = 0; (attr = modinfo_attrs[i]); i++) {
2219                if (attr->free)
2220                        attr->free(mod);
2221        }
2222}
2223
2224#ifdef CONFIG_KALLSYMS
2225
2226/* lookup symbol in given range of kernel_symbols */
2227static const struct kernel_symbol *lookup_symbol(const char *name,
2228        const struct kernel_symbol *start,
2229        const struct kernel_symbol *stop)
2230{
2231        return bsearch(name, start, stop - start,
2232                        sizeof(struct kernel_symbol), cmp_name);
2233}
2234
2235static int is_exported(const char *name, unsigned long value,
2236                       const struct module *mod)
2237{
2238        const struct kernel_symbol *ks;
2239        if (!mod)
2240                ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2241        else
2242                ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2243        return ks != NULL && ks->value == value;
2244}
2245
2246/* As per nm */
2247static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2248{
2249        const Elf_Shdr *sechdrs = info->sechdrs;
2250
2251        if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2252                if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2253                        return 'v';
2254                else
2255                        return 'w';
2256        }
2257        if (sym->st_shndx == SHN_UNDEF)
2258                return 'U';
2259        if (sym->st_shndx == SHN_ABS)
2260                return 'a';
2261        if (sym->st_shndx >= SHN_LORESERVE)
2262                return '?';
2263        if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2264                return 't';
2265        if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2266            && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2267                if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2268                        return 'r';
2269                else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2270                        return 'g';
2271                else
2272                        return 'd';
2273        }
2274        if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2275                if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2276                        return 's';
2277                else
2278                        return 'b';
2279        }
2280        if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2281                      ".debug")) {
2282                return 'n';
2283        }
2284        return '?';
2285}
2286
2287static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2288                           unsigned int shnum)
2289{
2290        const Elf_Shdr *sec;
2291
2292        if (src->st_shndx == SHN_UNDEF
2293            || src->st_shndx >= shnum
2294            || !src->st_name)
2295                return false;
2296
2297        sec = sechdrs + src->st_shndx;
2298        if (!(sec->sh_flags & SHF_ALLOC)
2299#ifndef CONFIG_KALLSYMS_ALL
2300            || !(sec->sh_flags & SHF_EXECINSTR)
2301#endif
2302            || (sec->sh_entsize & INIT_OFFSET_MASK))
2303                return false;
2304
2305        return true;
2306}
2307
2308/*
2309 * We only allocate and copy the strings needed by the parts of symtab
2310 * we keep.  This is simple, but has the effect of making multiple
2311 * copies of duplicates.  We could be more sophisticated, see
2312 * linux-kernel thread starting with
2313 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2314 */
2315static void layout_symtab(struct module *mod, struct load_info *info)
2316{
2317        Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2318        Elf_Shdr *strsect = info->sechdrs + info->index.str;
2319        const Elf_Sym *src;
2320        unsigned int i, nsrc, ndst, strtab_size = 0;
2321
2322        /* Put symbol section at end of init part of module. */
2323        symsect->sh_flags |= SHF_ALLOC;
2324        symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2325                                         info->index.sym) | INIT_OFFSET_MASK;
2326        pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2327
2328        src = (void *)info->hdr + symsect->sh_offset;
2329        nsrc = symsect->sh_size / sizeof(*src);
2330
2331        /* Compute total space required for the core symbols' strtab. */
2332        for (ndst = i = 0; i < nsrc; i++) {
2333                if (i == 0 ||
2334                    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2335                        strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2336                        ndst++;
2337                }
2338        }
2339
2340        /* Append room for core symbols at end of core part. */
2341        info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2342        info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2343        mod->core_size += strtab_size;
2344
2345        /* Put string table section at end of init part of module. */
2346        strsect->sh_flags |= SHF_ALLOC;
2347        strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2348                                         info->index.str) | INIT_OFFSET_MASK;
2349        pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2350}
2351
2352static void add_kallsyms(struct module *mod, const struct load_info *info)
2353{
2354        unsigned int i, ndst;
2355        const Elf_Sym *src;
2356        Elf_Sym *dst;
2357        char *s;
2358        Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2359
2360        mod->symtab = (void *)symsec->sh_addr;
2361        mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2362        /* Make sure we get permanent strtab: don't use info->strtab. */
2363        mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2364
2365        /* Set types up while we still have access to sections. */
2366        for (i = 0; i < mod->num_symtab; i++)
2367                mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2368
2369        mod->core_symtab = dst = mod->module_core + info->symoffs;
2370        mod->core_strtab = s = mod->module_core + info->stroffs;
2371        src = mod->symtab;
2372        for (ndst = i = 0; i < mod->num_symtab; i++) {
2373                if (i == 0 ||
2374                    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2375                        dst[ndst] = src[i];
2376                        dst[ndst++].st_name = s - mod->core_strtab;
2377                        s += strlcpy(s, &mod->strtab[src[i].st_name],
2378                                     KSYM_NAME_LEN) + 1;
2379                }
2380        }
2381        mod->core_num_syms = ndst;
2382}
2383#else
2384static inline void layout_symtab(struct module *mod, struct load_info *info)
2385{
2386}
2387
2388static void add_kallsyms(struct module *mod, const struct load_info *info)
2389{
2390}
2391#endif /* CONFIG_KALLSYMS */
2392
2393static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2394{
2395        if (!debug)
2396                return;
2397#ifdef CONFIG_DYNAMIC_DEBUG
2398        if (ddebug_add_module(debug, num, debug->modname))
2399                printk(KERN_ERR "dynamic debug error adding module: %s\n",
2400                                        debug->modname);
2401#endif
2402}
2403
2404static void dynamic_debug_remove(struct _ddebug *debug)
2405{
2406        if (debug)
2407                ddebug_remove_module(debug->modname);
2408}
2409
2410void * __weak module_alloc(unsigned long size)
2411{
2412        return vmalloc_exec(size);
2413}
2414
2415static void *module_alloc_update_bounds(unsigned long size)
2416{
2417        void *ret = module_alloc(size);
2418
2419        if (ret) {
2420                mutex_lock(&module_mutex);
2421                /* Update module bounds. */
2422                if ((unsigned long)ret < module_addr_min)
2423                        module_addr_min = (unsigned long)ret;
2424                if ((unsigned long)ret + size > module_addr_max)
2425                        module_addr_max = (unsigned long)ret + size;
2426                mutex_unlock(&module_mutex);
2427        }
2428        return ret;
2429}
2430
2431#ifdef CONFIG_DEBUG_KMEMLEAK
2432static void kmemleak_load_module(const struct module *mod,
2433                                 const struct load_info *info)
2434{
2435        unsigned int i;
2436
2437        /* only scan the sections containing data */
2438        kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2439
2440        for (i = 1; i < info->hdr->e_shnum; i++) {
2441                /* Scan all writable sections that's not executable */
2442                if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2443                    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2444                    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2445                        continue;
2446
2447                kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2448                                   info->sechdrs[i].sh_size, GFP_KERNEL);
2449        }
2450}
2451#else
2452static inline void kmemleak_load_module(const struct module *mod,
2453                                        const struct load_info *info)
2454{
2455}
2456#endif
2457
2458#ifdef CONFIG_MODULE_SIG
2459static int module_sig_check(struct load_info *info)
2460{
2461        int err = -ENOKEY;
2462        const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2463        const void *mod = info->hdr;
2464
2465        if (info->len > markerlen &&
2466            memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2467                /* We truncate the module to discard the signature */
2468                info->len -= markerlen;
2469                err = mod_verify_sig(mod, &info->len);
2470        }
2471
2472        if (!err) {
2473                info->sig_ok = true;
2474                return 0;
2475        }
2476
2477        /* Not having a signature is only an error if we're strict. */
2478        if (err < 0 && fips_enabled)
2479                panic("Module verification failed with error %d in FIPS mode\n",
2480                      err);
2481        if (err == -ENOKEY && !sig_enforce)
2482                err = 0;
2483
2484        return err;
2485}
2486#else /* !CONFIG_MODULE_SIG */
2487static int module_sig_check(struct load_info *info)
2488{
2489        return 0;
2490}
2491#endif /* !CONFIG_MODULE_SIG */
2492
2493/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2494static int elf_header_check(struct load_info *info)
2495{
2496        if (info->len < sizeof(*(info->hdr)))
2497                return -ENOEXEC;
2498
2499        if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2500            || info->hdr->e_type != ET_REL
2501            || !elf_check_arch(info->hdr)
2502            || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2503                return -ENOEXEC;
2504
2505        if (info->hdr->e_shoff >= info->len
2506            || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2507                info->len - info->hdr->e_shoff))
2508                return -ENOEXEC;
2509
2510        return 0;
2511}
2512
2513/* Sets info->hdr and info->len. */
2514static int copy_module_from_user(const void __user *umod, unsigned long len,
2515                                  struct load_info *info)
2516{
2517        int err;
2518
2519        info->len = len;
2520        if (info->len < sizeof(*(info->hdr)))
2521                return -ENOEXEC;
2522
2523        err = security_kernel_module_from_file(NULL);
2524        if (err)
2525                return err;
2526
2527        /* Suck in entire file: we'll want most of it. */
2528        info->hdr = vmalloc(info->len);
2529        if (!info->hdr)
2530                return -ENOMEM;
2531
2532        if (copy_from_user(info->hdr, umod, info->len) != 0) {
2533                vfree(info->hdr);
2534                return -EFAULT;
2535        }
2536
2537        return 0;
2538}
2539
2540/* Sets info->hdr and info->len. */
2541static int copy_module_from_fd(int fd, struct load_info *info)
2542{
2543        struct file *file;
2544        int err;
2545        struct kstat stat;
2546        loff_t pos;
2547        ssize_t bytes = 0;
2548
2549        file = fget(fd);
2550        if (!file)
2551                return -ENOEXEC;
2552
2553        err = security_kernel_module_from_file(file);
2554        if (err)
2555                goto out;
2556
2557        err = vfs_getattr(&file->f_path, &stat);
2558        if (err)
2559                goto out;
2560
2561        if (stat.size > INT_MAX) {
2562                err = -EFBIG;
2563                goto out;
2564        }
2565
2566        /* Don't hand 0 to vmalloc, it whines. */
2567        if (stat.size == 0) {
2568                err = -EINVAL;
2569                goto out;
2570        }
2571
2572        info->hdr = vmalloc(stat.size);
2573        if (!info->hdr) {
2574                err = -ENOMEM;
2575                goto out;
2576        }
2577
2578        pos = 0;
2579        while (pos < stat.size) {
2580                bytes = kernel_read(file, pos, (char *)(info->hdr) + pos,
2581                                    stat.size - pos);
2582                if (bytes < 0) {
2583                        vfree(info->hdr);
2584                        err = bytes;
2585                        goto out;
2586                }
2587                if (bytes == 0)
2588                        break;
2589                pos += bytes;
2590        }
2591        info->len = pos;
2592
2593out:
2594        fput(file);
2595        return err;
2596}
2597
2598static void free_copy(struct load_info *info)
2599{
2600        vfree(info->hdr);
2601}
2602
2603static int rewrite_section_headers(struct load_info *info, int flags)
2604{
2605        unsigned int i;
2606
2607        /* This should always be true, but let's be sure. */
2608        info->sechdrs[0].sh_addr = 0;
2609
2610        for (i = 1; i < info->hdr->e_shnum; i++) {
2611                Elf_Shdr *shdr = &info->sechdrs[i];
2612                if (shdr->sh_type != SHT_NOBITS
2613                    && info->len < shdr->sh_offset + shdr->sh_size) {
2614                        printk(KERN_ERR "Module len %lu truncated\n",
2615                               info->len);
2616                        return -ENOEXEC;
2617                }
2618
2619                /* Mark all sections sh_addr with their address in the
2620                   temporary image. */
2621                shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2622
2623#ifndef CONFIG_MODULE_UNLOAD
2624                /* Don't load .exit sections */
2625                if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2626                        shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2627#endif
2628        }
2629
2630        /* Track but don't keep modinfo and version sections. */
2631        if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2632                info->index.vers = 0; /* Pretend no __versions section! */
2633        else
2634                info->index.vers = find_sec(info, "__versions");
2635        info->index.info = find_sec(info, ".modinfo");
2636        info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2637        info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2638        return 0;
2639}
2640
2641/*
2642 * Set up our basic convenience variables (pointers to section headers,
2643 * search for module section index etc), and do some basic section
2644 * verification.
2645 *
2646 * Return the temporary module pointer (we'll replace it with the final
2647 * one when we move the module sections around).
2648 */
2649static struct module *setup_load_info(struct load_info *info, int flags)
2650{
2651        unsigned int i;
2652        int err;
2653        struct module *mod;
2654
2655        /* Set up the convenience variables */
2656        info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2657        info->secstrings = (void *)info->hdr
2658                + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2659
2660        err = rewrite_section_headers(info, flags);
2661        if (err)
2662                return ERR_PTR(err);
2663
2664        /* Find internal symbols and strings. */
2665        for (i = 1; i < info->hdr->e_shnum; i++) {
2666                if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2667                        info->index.sym = i;
2668                        info->index.str = info->sechdrs[i].sh_link;
2669                        info->strtab = (char *)info->hdr
2670                                + info->sechdrs[info->index.str].sh_offset;
2671                        break;
2672                }
2673        }
2674
2675        info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2676        if (!info->index.mod) {
2677                printk(KERN_WARNING "No module found in object\n");
2678                return ERR_PTR(-ENOEXEC);
2679        }
2680        /* This is temporary: point mod into copy of data. */
2681        mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2682
2683        if (info->index.sym == 0) {
2684                printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2685                       mod->name);
2686                return ERR_PTR(-ENOEXEC);
2687        }
2688
2689        info->index.pcpu = find_pcpusec(info);
2690
2691        /* Check module struct version now, before we try to use module. */
2692        if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2693                return ERR_PTR(-ENOEXEC);
2694
2695        return mod;
2696}
2697
2698static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2699{
2700        const char *modmagic = get_modinfo(info, "vermagic");
2701        int err;
2702
2703        if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2704                modmagic = NULL;
2705
2706        /* This is allowed: modprobe --force will invalidate it. */
2707        if (!modmagic) {
2708                err = try_to_force_load(mod, "bad vermagic");
2709                if (err)
2710                        return err;
2711        } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2712                printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2713                       mod->name, modmagic, vermagic);
2714                return -ENOEXEC;
2715        }
2716
2717        if (!get_modinfo(info, "intree"))
2718                add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2719
2720        if (get_modinfo(info, "staging")) {
2721                add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2722                printk(KERN_WARNING "%s: module is from the staging directory,"
2723                       " the quality is unknown, you have been warned.\n",
2724                       mod->name);
2725        }
2726
2727        /* Set up license info based on the info section */
2728        set_license(mod, get_modinfo(info, "license"));
2729
2730        return 0;
2731}
2732
2733static void find_module_sections(struct module *mod, struct load_info *info)
2734{
2735        mod->kp = section_objs(info, "__param",
2736                               sizeof(*mod->kp), &mod->num_kp);
2737        mod->syms = section_objs(info, "__ksymtab",
2738                                 sizeof(*mod->syms), &mod->num_syms);
2739        mod->crcs = section_addr(info, "__kcrctab");
2740        mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2741                                     sizeof(*mod->gpl_syms),
2742                                     &mod->num_gpl_syms);
2743        mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2744        mod->gpl_future_syms = section_objs(info,
2745                                            "__ksymtab_gpl_future",
2746                                            sizeof(*mod->gpl_future_syms),
2747                                            &mod->num_gpl_future_syms);
2748        mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2749
2750#ifdef CONFIG_UNUSED_SYMBOLS
2751        mod->unused_syms = section_objs(info, "__ksymtab_unused",
2752                                        sizeof(*mod->unused_syms),
2753                                        &mod->num_unused_syms);
2754        mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2755        mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2756                                            sizeof(*mod->unused_gpl_syms),
2757                                            &mod->num_unused_gpl_syms);
2758        mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2759#endif
2760#ifdef CONFIG_CONSTRUCTORS
2761        mod->ctors = section_objs(info, ".ctors",
2762                                  sizeof(*mod->ctors), &mod->num_ctors);
2763#endif
2764
2765#ifdef CONFIG_TRACEPOINTS
2766        mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2767                                             sizeof(*mod->tracepoints_ptrs),
2768                                             &mod->num_tracepoints);
2769#endif
2770#ifdef HAVE_JUMP_LABEL
2771        mod->jump_entries = section_objs(info, "__jump_table",
2772                                        sizeof(*mod->jump_entries),
2773                                        &mod->num_jump_entries);
2774#endif
2775#ifdef CONFIG_EVENT_TRACING
2776        mod->trace_events = section_objs(info, "_ftrace_events",
2777                                         sizeof(*mod->trace_events),
2778                                         &mod->num_trace_events);
2779#endif
2780#ifdef CONFIG_TRACING
2781        mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2782                                         sizeof(*mod->trace_bprintk_fmt_start),
2783                                         &mod->num_trace_bprintk_fmt);
2784#endif
2785#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2786        /* sechdrs[0].sh_size is always zero */
2787        mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2788                                             sizeof(*mod->ftrace_callsites),
2789                                             &mod->num_ftrace_callsites);
2790#endif
2791
2792        mod->extable = section_objs(info, "__ex_table",
2793                                    sizeof(*mod->extable), &mod->num_exentries);
2794
2795        if (section_addr(info, "__obsparm"))
2796                printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2797                       mod->name);
2798
2799        info->debug = section_objs(info, "__verbose",
2800                                   sizeof(*info->debug), &info->num_debug);
2801}
2802
2803static int move_module(struct module *mod, struct load_info *info)
2804{
2805        int i;
2806        void *ptr;
2807
2808        /* Do the allocs. */
2809        ptr = module_alloc_update_bounds(mod->core_size);
2810        /*
2811         * The pointer to this block is stored in the module structure
2812         * which is inside the block. Just mark it as not being a
2813         * leak.
2814         */
2815        kmemleak_not_leak(ptr);
2816        if (!ptr)
2817                return -ENOMEM;
2818
2819        memset(ptr, 0, mod->core_size);
2820        mod->module_core = ptr;
2821
2822        if (mod->init_size) {
2823                ptr = module_alloc_update_bounds(mod->init_size);
2824                /*
2825                 * The pointer to this block is stored in the module structure
2826                 * which is inside the block. This block doesn't need to be
2827                 * scanned as it contains data and code that will be freed
2828                 * after the module is initialized.
2829                 */
2830                kmemleak_ignore(ptr);
2831                if (!ptr) {
2832                        module_free(mod, mod->module_core);
2833                        return -ENOMEM;
2834                }
2835                memset(ptr, 0, mod->init_size);
2836                mod->module_init = ptr;
2837        } else
2838                mod->module_init = NULL;
2839
2840        /* Transfer each section which specifies SHF_ALLOC */
2841        pr_debug("final section addresses:\n");
2842        for (i = 0; i < info->hdr->e_shnum; i++) {
2843                void *dest;
2844                Elf_Shdr *shdr = &info->sechdrs[i];
2845
2846                if (!(shdr->sh_flags & SHF_ALLOC))
2847                        continue;
2848
2849                if (shdr->sh_entsize & INIT_OFFSET_MASK)
2850                        dest = mod->module_init
2851                                + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2852                else
2853                        dest = mod->module_core + shdr->sh_entsize;
2854
2855                if (shdr->sh_type != SHT_NOBITS)
2856                        memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2857                /* Update sh_addr to point to copy in image. */
2858                shdr->sh_addr = (unsigned long)dest;
2859                pr_debug("\t0x%lx %s\n",
2860                         (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2861        }
2862
2863        return 0;
2864}
2865
2866static int check_module_license_and_versions(struct module *mod)
2867{
2868        /*
2869         * ndiswrapper is under GPL by itself, but loads proprietary modules.
2870         * Don't use add_taint_module(), as it would prevent ndiswrapper from
2871         * using GPL-only symbols it needs.
2872         */
2873        if (strcmp(mod->name, "ndiswrapper") == 0)
2874                add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2875
2876        /* driverloader was caught wrongly pretending to be under GPL */
2877        if (strcmp(mod->name, "driverloader") == 0)
2878                add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2879                                 LOCKDEP_NOW_UNRELIABLE);
2880
2881        /* lve claims to be GPL but upstream won't provide source */
2882        if (strcmp(mod->name, "lve") == 0)
2883                add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2884                                 LOCKDEP_NOW_UNRELIABLE);
2885
2886#ifdef CONFIG_MODVERSIONS
2887        if ((mod->num_syms && !mod->crcs)
2888            || (mod->num_gpl_syms && !mod->gpl_crcs)
2889            || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2890#ifdef CONFIG_UNUSED_SYMBOLS
2891            || (mod->num_unused_syms && !mod->unused_crcs)
2892            || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2893#endif
2894                ) {
2895                return try_to_force_load(mod,
2896                                         "no versions for exported symbols");
2897        }
2898#endif
2899        return 0;
2900}
2901
2902static void flush_module_icache(const struct module *mod)
2903{
2904        mm_segment_t old_fs;
2905
2906        /* flush the icache in correct context */
2907        old_fs = get_fs();
2908        set_fs(KERNEL_DS);
2909
2910        /*
2911         * Flush the instruction cache, since we've played with text.
2912         * Do it before processing of module parameters, so the module
2913         * can provide parameter accessor functions of its own.
2914         */
2915        if (mod->module_init)
2916                flush_icache_range((unsigned long)mod->module_init,
2917                                   (unsigned long)mod->module_init
2918                                   + mod->init_size);
2919        flush_icache_range((unsigned long)mod->module_core,
2920                           (unsigned long)mod->module_core + mod->core_size);
2921
2922        set_fs(old_fs);
2923}
2924
2925int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2926                                     Elf_Shdr *sechdrs,
2927                                     char *secstrings,
2928                                     struct module *mod)
2929{
2930        return 0;
2931}
2932
2933static struct module *layout_and_allocate(struct load_info *info, int flags)
2934{
2935        /* Module within temporary copy. */
2936        struct module *mod;
2937        int err;
2938
2939        mod = setup_load_info(info, flags);
2940        if (IS_ERR(mod))
2941                return mod;
2942
2943        err = check_modinfo(mod, info, flags);
2944        if (err)
2945                return ERR_PTR(err);
2946
2947        /* Allow arches to frob section contents and sizes.  */
2948        err = module_frob_arch_sections(info->hdr, info->sechdrs,
2949                                        info->secstrings, mod);
2950        if (err < 0)
2951                return ERR_PTR(err);
2952
2953        /* We will do a special allocation for per-cpu sections later. */
2954        info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2955
2956        /* Determine total sizes, and put offsets in sh_entsize.  For now
2957           this is done generically; there doesn't appear to be any
2958           special cases for the architectures. */
2959        layout_sections(mod, info);
2960        layout_symtab(mod, info);
2961
2962        /* Allocate and move to the final place */
2963        err = move_module(mod, info);
2964        if (err)
2965                return ERR_PTR(err);
2966
2967        /* Module has been copied to its final place now: return it. */
2968        mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2969        kmemleak_load_module(mod, info);
2970        return mod;
2971}
2972
2973/* mod is no longer valid after this! */
2974static void module_deallocate(struct module *mod, struct load_info *info)
2975{
2976        percpu_modfree(mod);
2977        module_free(mod, mod->module_init);
2978        module_free(mod, mod->module_core);
2979}
2980
2981int __weak module_finalize(const Elf_Ehdr *hdr,
2982                           const Elf_Shdr *sechdrs,
2983                           struct module *me)
2984{
2985        return 0;
2986}
2987
2988static int post_relocation(struct module *mod, const struct load_info *info)
2989{
2990        /* Sort exception table now relocations are done. */
2991        sort_extable(mod->extable, mod->extable + mod->num_exentries);
2992
2993        /* Copy relocated percpu area over. */
2994        percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2995                       info->sechdrs[info->index.pcpu].sh_size);
2996
2997        /* Setup kallsyms-specific fields. */
2998        add_kallsyms(mod, info);
2999
3000        /* Arch-specific module finalizing. */
3001        return module_finalize(info->hdr, info->sechdrs, mod);
3002}
3003
3004/* Is this module of this name done loading?  No locks held. */
3005static bool finished_loading(const char *name)
3006{
3007        struct module *mod;
3008        bool ret;
3009
3010        mutex_lock(&module_mutex);
3011        mod = find_module_all(name, strlen(name), true);
3012        ret = !mod || mod->state == MODULE_STATE_LIVE
3013                || mod->state == MODULE_STATE_GOING;
3014        mutex_unlock(&module_mutex);
3015
3016        return ret;
3017}
3018
3019/* Call module constructors. */
3020static void do_mod_ctors(struct module *mod)
3021{
3022#ifdef CONFIG_CONSTRUCTORS
3023        unsigned long i;
3024
3025        for (i = 0; i < mod->num_ctors; i++)
3026                mod->ctors[i]();
3027#endif
3028}
3029
3030/* This is where the real work happens */
3031static int do_init_module(struct module *mod)
3032{
3033        int ret = 0;
3034
3035        /*
3036         * We want to find out whether @mod uses async during init.  Clear
3037         * PF_USED_ASYNC.  async_schedule*() will set it.
3038         */
3039        current->flags &= ~PF_USED_ASYNC;
3040
3041        blocking_notifier_call_chain(&module_notify_list,
3042                        MODULE_STATE_COMING, mod);
3043
3044        /* Set RO and NX regions for core */
3045        set_section_ro_nx(mod->module_core,
3046                                mod->core_text_size,
3047                                mod->core_ro_size,
3048                                mod->core_size);
3049
3050        /* Set RO and NX regions for init */
3051        set_section_ro_nx(mod->module_init,
3052                                mod->init_text_size,
3053                                mod->init_ro_size,
3054                                mod->init_size);
3055
3056        do_mod_ctors(mod);
3057        /* Start the module */
3058        if (mod->init != NULL)
3059                ret = do_one_initcall(mod->init);
3060        if (ret < 0) {
3061                /* Init routine failed: abort.  Try to protect us from
3062                   buggy refcounters. */
3063                mod->state = MODULE_STATE_GOING;
3064                synchronize_sched();
3065                module_put(mod);
3066                blocking_notifier_call_chain(&module_notify_list,
3067                                             MODULE_STATE_GOING, mod);
3068                free_module(mod);
3069                wake_up_all(&module_wq);
3070                return ret;
3071        }
3072        if (ret > 0) {
3073                printk(KERN_WARNING
3074"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
3075"%s: loading module anyway...\n",
3076                       __func__, mod->name, ret,
3077                       __func__);
3078                dump_stack();
3079        }
3080
3081        /* Now it's a first class citizen! */
3082        mod->state = MODULE_STATE_LIVE;
3083        blocking_notifier_call_chain(&module_notify_list,
3084                                     MODULE_STATE_LIVE, mod);
3085
3086        /*
3087         * We need to finish all async code before the module init sequence
3088         * is done.  This has potential to deadlock.  For example, a newly
3089         * detected block device can trigger request_module() of the
3090         * default iosched from async probing task.  Once userland helper
3091         * reaches here, async_synchronize_full() will wait on the async
3092         * task waiting on request_module() and deadlock.
3093         *
3094         * This deadlock is avoided by perfomring async_synchronize_full()
3095         * iff module init queued any async jobs.  This isn't a full
3096         * solution as it will deadlock the same if module loading from
3097         * async jobs nests more than once; however, due to the various
3098         * constraints, this hack seems to be the best option for now.
3099         * Please refer to the following thread for details.
3100         *
3101         * http://thread.gmane.org/gmane.linux.kernel/1420814
3102         */
3103        if (current->flags & PF_USED_ASYNC)
3104                async_synchronize_full();
3105
3106        mutex_lock(&module_mutex);
3107        /* Drop initial reference. */
3108        module_put(mod);
3109        trim_init_extable(mod);
3110#ifdef CONFIG_KALLSYMS
3111        mod->num_symtab = mod->core_num_syms;
3112        mod->symtab = mod->core_symtab;
3113        mod->strtab = mod->core_strtab;
3114#endif
3115        unset_module_init_ro_nx(mod);
3116        module_free(mod, mod->module_init);
3117        mod->module_init = NULL;
3118        mod->init_size = 0;
3119        mod->init_ro_size = 0;
3120        mod->init_text_size = 0;
3121        mutex_unlock(&module_mutex);
3122        wake_up_all(&module_wq);
3123
3124        return 0;
3125}
3126
3127static int may_init_module(void)
3128{
3129        if (!capable(CAP_SYS_MODULE) || modules_disabled)
3130                return -EPERM;
3131
3132        return 0;
3133}
3134
3135/*
3136 * We try to place it in the list now to make sure it's unique before
3137 * we dedicate too many resources.  In particular, temporary percpu
3138 * memory exhaustion.
3139 */
3140static int add_unformed_module(struct module *mod)
3141{
3142        int err;
3143        struct module *old;
3144
3145        mod->state = MODULE_STATE_UNFORMED;
3146
3147again:
3148        mutex_lock(&module_mutex);
3149        old = find_module_all(mod->name, strlen(mod->name), true);
3150        if (old != NULL) {
3151                if (old->state == MODULE_STATE_COMING
3152                    || old->state == MODULE_STATE_UNFORMED) {
3153                        /* Wait in case it fails to load. */
3154                        mutex_unlock(&module_mutex);
3155                        err = wait_event_interruptible(module_wq,
3156                                               finished_loading(mod->name));
3157                        if (err)
3158                                goto out_unlocked;
3159                        goto again;
3160                }
3161                err = -EEXIST;
3162                goto out;
3163        }
3164        list_add_rcu(&mod->list, &modules);
3165        err = 0;
3166
3167out:
3168        mutex_unlock(&module_mutex);
3169out_unlocked:
3170        return err;
3171}
3172
3173static int complete_formation(struct module *mod, struct load_info *info)
3174{
3175        int err;
3176
3177        mutex_lock(&module_mutex);
3178
3179        /* Find duplicate symbols (must be called under lock). */
3180        err = verify_export_symbols(mod);
3181        if (err < 0)
3182                goto out;
3183
3184        /* This relies on module_mutex for list integrity. */
3185        module_bug_finalize(info->hdr, info->sechdrs, mod);
3186
3187        /* Mark state as coming so strong_try_module_get() ignores us,
3188         * but kallsyms etc. can see us. */
3189        mod->state = MODULE_STATE_COMING;
3190
3191out:
3192        mutex_unlock(&module_mutex);
3193        return err;
3194}
3195
3196static int unknown_module_param_cb(char *param, char *val, const char *modname)
3197{
3198        /* Check for magic 'dyndbg' arg */ 
3199        int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3200        if (ret != 0) {
3201                printk(KERN_WARNING "%s: unknown parameter '%s' ignored\n",
3202                       modname, param);
3203        }
3204        return 0;
3205}
3206
3207/* Allocate and load the module: note that size of section 0 is always
3208   zero, and we rely on this for optional sections. */
3209static int load_module(struct load_info *info, const char __user *uargs,
3210                       int flags)
3211{
3212        struct module *mod;
3213        long err;
3214
3215        err = module_sig_check(info);
3216        if (err)
3217                goto free_copy;
3218
3219        err = elf_header_check(info);
3220        if (err)
3221                goto free_copy;
3222
3223        /* Figure out module layout, and allocate all the memory. */
3224        mod = layout_and_allocate(info, flags);
3225        if (IS_ERR(mod)) {
3226                err = PTR_ERR(mod);
3227                goto free_copy;
3228        }
3229
3230        /* Reserve our place in the list. */
3231        err = add_unformed_module(mod);
3232        if (err)
3233                goto free_module;
3234
3235#ifdef CONFIG_MODULE_SIG
3236        mod->sig_ok = info->sig_ok;
3237        if (!mod->sig_ok) {
3238                printk_once(KERN_NOTICE
3239                            "%s: module verification failed: signature and/or"
3240                            " required key missing - tainting kernel\n",
3241                            mod->name);
3242                add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_STILL_OK);
3243        }
3244#endif
3245
3246        /* To avoid stressing percpu allocator, do this once we're unique. */
3247        err = percpu_modalloc(mod, info);
3248        if (err)
3249                goto unlink_mod;
3250
3251        /* Now module is in final location, initialize linked lists, etc. */
3252        err = module_unload_init(mod);
3253        if (err)
3254                goto unlink_mod;
3255
3256        /* Now we've got everything in the final locations, we can
3257         * find optional sections. */
3258        find_module_sections(mod, info);
3259
3260        err = check_module_license_and_versions(mod);
3261        if (err)
3262                goto free_unload;
3263
3264        /* Set up MODINFO_ATTR fields */
3265        setup_modinfo(mod, info);
3266
3267        /* Fix up syms, so that st_value is a pointer to location. */
3268        err = simplify_symbols(mod, info);
3269        if (err < 0)
3270                goto free_modinfo;
3271
3272        err = apply_relocations(mod, info);
3273        if (err < 0)
3274                goto free_modinfo;
3275
3276        err = post_relocation(mod, info);
3277        if (err < 0)
3278                goto free_modinfo;
3279
3280        flush_module_icache(mod);
3281
3282        /* Now copy in args */
3283        mod->args = strndup_user(uargs, ~0UL >> 1);
3284        if (IS_ERR(mod->args)) {
3285                err = PTR_ERR(mod->args);
3286                goto free_arch_cleanup;
3287        }
3288
3289        dynamic_debug_setup(info->debug, info->num_debug);
3290
3291        /* Finally it's fully formed, ready to start executing. */
3292        err = complete_formation(mod, info);
3293        if (err)
3294                goto ddebug_cleanup;
3295
3296        /* Module is ready to execute: parsing args may do that. */
3297        err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3298                         -32768, 32767, unknown_module_param_cb);
3299        if (err < 0)
3300                goto bug_cleanup;
3301
3302        /* Link in to syfs. */
3303        err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3304        if (err < 0)
3305                goto bug_cleanup;
3306
3307        /* Get rid of temporary copy. */
3308        free_copy(info);
3309
3310        /* Done! */
3311        trace_module_load(mod);
3312
3313        return do_init_module(mod);
3314
3315 bug_cleanup:
3316        /* module_bug_cleanup needs module_mutex protection */
3317        mutex_lock(&module_mutex);
3318        module_bug_cleanup(mod);
3319        mutex_unlock(&module_mutex);
3320 ddebug_cleanup:
3321        dynamic_debug_remove(info->debug);
3322        synchronize_sched();
3323        kfree(mod->args);
3324 free_arch_cleanup:
3325        module_arch_cleanup(mod);
3326 free_modinfo:
3327        free_modinfo(mod);
3328 free_unload:
3329        module_unload_free(mod);
3330 unlink_mod:
3331        mutex_lock(&module_mutex);
3332        /* Unlink carefully: kallsyms could be walking list. */
3333        list_del_rcu(&mod->list);
3334        wake_up_all(&module_wq);
3335        mutex_unlock(&module_mutex);
3336 free_module:
3337        module_deallocate(mod, info);
3338 free_copy:
3339        free_copy(info);
3340        return err;
3341}
3342
3343SYSCALL_DEFINE3(init_module, void __user *, umod,
3344                unsigned long, len, const char __user *, uargs)
3345{
3346        int err;
3347        struct load_info info = { };
3348
3349        err = may_init_module();
3350        if (err)
3351                return err;
3352
3353        pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3354               umod, len, uargs);
3355
3356        err = copy_module_from_user(umod, len, &info);
3357        if (err)
3358                return err;
3359
3360        return load_module(&info, uargs, 0);
3361}
3362
3363SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3364{
3365        int err;
3366        struct load_info info = { };
3367
3368        err = may_init_module();
3369        if (err)
3370                return err;
3371
3372        pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3373
3374        if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3375                      |MODULE_INIT_IGNORE_VERMAGIC))
3376                return -EINVAL;
3377
3378        err = copy_module_from_fd(fd, &info);
3379        if (err)
3380                return err;
3381
3382        return load_module(&info, uargs, flags);
3383}
3384
3385static inline int within(unsigned long addr, void *start, unsigned long size)
3386{
3387        return ((void *)addr >= start && (void *)addr < start + size);
3388}
3389
3390#ifdef CONFIG_KALLSYMS
3391/*
3392 * This ignores the intensely annoying "mapping symbols" found
3393 * in ARM ELF files: $a, $t and $d.
3394 */
3395static inline int is_arm_mapping_symbol(const char *str)
3396{
3397        return str[0] == '$' && strchr("atd", str[1])
3398               && (str[2] == '\0' || str[2] == '.');
3399}
3400
3401static const char *get_ksymbol(struct module *mod,
3402                               unsigned long addr,
3403                               unsigned long *size,
3404                               unsigned long *offset)
3405{
3406        unsigned int i, best = 0;
3407        unsigned long nextval;
3408
3409        /* At worse, next value is at end of module */
3410        if (within_module_init(addr, mod))
3411                nextval = (unsigned long)mod->module_init+mod->init_text_size;
3412        else
3413                nextval = (unsigned long)mod->module_core+mod->core_text_size;
3414
3415        /* Scan for closest preceding symbol, and next symbol. (ELF
3416           starts real symbols at 1). */
3417        for (i = 1; i < mod->num_symtab; i++) {
3418                if (mod->symtab[i].st_shndx == SHN_UNDEF)
3419                        continue;
3420
3421                /* We ignore unnamed symbols: they're uninformative
3422                 * and inserted at a whim. */
3423                if (mod->symtab[i].st_value <= addr
3424                    && mod->symtab[i].st_value > mod->symtab[best].st_value
3425                    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3426                    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3427                        best = i;
3428                if (mod->symtab[i].st_value > addr
3429                    && mod->symtab[i].st_value < nextval
3430                    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3431                    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3432                        nextval = mod->symtab[i].st_value;
3433        }
3434
3435        if (!best)
3436                return NULL;
3437
3438        if (size)
3439                *size = nextval - mod->symtab[best].st_value;
3440        if (offset)
3441                *offset = addr - mod->symtab[best].st_value;
3442        return mod->strtab + mod->symtab[best].st_name;
3443}
3444
3445/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3446 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3447const char *module_address_lookup(unsigned long addr,
3448                            unsigned long *size,
3449                            unsigned long *offset,
3450                            char **modname,
3451                            char *namebuf)
3452{
3453        struct module *mod;
3454        const char *ret = NULL;
3455
3456        preempt_disable();
3457        list_for_each_entry_rcu(mod, &modules, list) {
3458                if (mod->state == MODULE_STATE_UNFORMED)
3459                        continue;
3460                if (within_module_init(addr, mod) ||
3461                    within_module_core(addr, mod)) {
3462                        if (modname)
3463                                *modname = mod->name;
3464                        ret = get_ksymbol(mod, addr, size, offset);
3465                        break;
3466                }
3467        }
3468        /* Make a copy in here where it's safe */
3469        if (ret) {
3470                strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3471                ret = namebuf;
3472        }
3473        preempt_enable();
3474        return ret;
3475}
3476
3477int lookup_module_symbol_name(unsigned long addr, char *symname)
3478{
3479        struct module *mod;
3480
3481        preempt_disable();
3482        list_for_each_entry_rcu(mod, &modules, list) {
3483                if (mod->state == MODULE_STATE_UNFORMED)
3484                        continue;
3485                if (within_module_init(addr, mod) ||
3486                    within_module_core(addr, mod)) {
3487                        const char *sym;
3488
3489                        sym = get_ksymbol(mod, addr, NULL, NULL);
3490                        if (!sym)
3491                                goto out;
3492                        strlcpy(symname, sym, KSYM_NAME_LEN);
3493                        preempt_enable();
3494                        return 0;
3495                }
3496        }
3497out:
3498        preempt_enable();
3499        return -ERANGE;
3500}
3501
3502int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3503                        unsigned long *offset, char *modname, char *name)
3504{
3505        struct module *mod;
3506
3507        preempt_disable();
3508        list_for_each_entry_rcu(mod, &modules, list) {
3509                if (mod->state == MODULE_STATE_UNFORMED)
3510                        continue;
3511                if (within_module_init(addr, mod) ||
3512                    within_module_core(addr, mod)) {
3513                        const char *sym;
3514
3515                        sym = get_ksymbol(mod, addr, size, offset);
3516                        if (!sym)
3517                                goto out;
3518                        if (modname)
3519                                strlcpy(modname, mod->name, MODULE_NAME_LEN);
3520                        if (name)
3521                                strlcpy(name, sym, KSYM_NAME_LEN);
3522                        preempt_enable();
3523                        return 0;
3524                }
3525        }
3526out:
3527        preempt_enable();
3528        return -ERANGE;
3529}
3530
3531int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3532                        char *name, char *module_name, int *exported)
3533{
3534        struct module *mod;
3535
3536        preempt_disable();
3537        list_for_each_entry_rcu(mod, &modules, list) {
3538                if (mod->state == MODULE_STATE_UNFORMED)
3539                        continue;
3540                if (symnum < mod->num_symtab) {
3541                        *value = mod->symtab[symnum].st_value;
3542                        *type = mod->symtab[symnum].st_info;
3543                        strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3544                                KSYM_NAME_LEN);
3545                        strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3546                        *exported = is_exported(name, *value, mod);
3547                        preempt_enable();
3548                        return 0;
3549                }
3550                symnum -= mod->num_symtab;
3551        }
3552        preempt_enable();
3553        return -ERANGE;
3554}
3555
3556static unsigned long mod_find_symname(struct module *mod, const char *name)
3557{
3558        unsigned int i;
3559
3560        for (i = 0; i < mod->num_symtab; i++)
3561                if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3562                    mod->symtab[i].st_info != 'U')
3563                        return mod->symtab[i].st_value;
3564        return 0;
3565}
3566
3567/* Look for this name: can be of form module:name. */
3568unsigned long module_kallsyms_lookup_name(const char *name)
3569{
3570        struct module *mod;
3571        char *colon;
3572        unsigned long ret = 0;
3573
3574        /* Don't lock: we're in enough trouble already. */
3575        preempt_disable();
3576        if ((colon = strchr(name, ':')) != NULL) {
3577                if ((mod = find_module_all(name, colon - name, false)) != NULL)
3578                        ret = mod_find_symname(mod, colon+1);
3579        } else {
3580                list_for_each_entry_rcu(mod, &modules, list) {
3581                        if (mod->state == MODULE_STATE_UNFORMED)
3582                                continue;
3583                        if ((ret = mod_find_symname(mod, name)) != 0)
3584                                break;
3585                }
3586        }
3587        preempt_enable();
3588        return ret;
3589}
3590
3591int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3592                                             struct module *, unsigned long),
3593                                   void *data)
3594{
3595        struct module *mod;
3596        unsigned int i;
3597        int ret;
3598
3599        list_for_each_entry(mod, &modules, list) {
3600                if (mod->state == MODULE_STATE_UNFORMED)
3601                        continue;
3602                for (i = 0; i < mod->num_symtab; i++) {
3603                        ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3604                                 mod, mod->symtab[i].st_value);
3605                        if (ret != 0)
3606                                return ret;
3607                }
3608        }
3609        return 0;
3610}
3611#endif /* CONFIG_KALLSYMS */
3612
3613static char *module_flags(struct module *mod, char *buf)
3614{
3615        int bx = 0;
3616
3617        BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3618        if (mod->taints ||
3619            mod->state == MODULE_STATE_GOING ||
3620            mod->state == MODULE_STATE_COMING) {
3621                buf[bx++] = '(';
3622                bx += module_flags_taint(mod, buf + bx);
3623                /* Show a - for module-is-being-unloaded */
3624                if (mod->state == MODULE_STATE_GOING)
3625                        buf[bx++] = '-';
3626                /* Show a + for module-is-being-loaded */
3627                if (mod->state == MODULE_STATE_COMING)
3628                        buf[bx++] = '+';
3629                buf[bx++] = ')';
3630        }
3631        buf[bx] = '\0';
3632
3633        return buf;
3634}
3635
3636#ifdef CONFIG_PROC_FS
3637/* Called by the /proc file system to return a list of modules. */
3638static void *m_start(struct seq_file *m, loff_t *pos)
3639{
3640        mutex_lock(&module_mutex);
3641        return seq_list_start(&modules, *pos);
3642}
3643
3644static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3645{
3646        return seq_list_next(p, &modules, pos);
3647}
3648
3649static void m_stop(struct seq_file *m, void *p)
3650{
3651        mutex_unlock(&module_mutex);
3652}
3653
3654static int m_show(struct seq_file *m, void *p)
3655{
3656        struct module *mod = list_entry(p, struct module, list);
3657        char buf[8];
3658
3659        /* We always ignore unformed modules. */
3660        if (mod->state == MODULE_STATE_UNFORMED)
3661                return 0;
3662
3663        seq_printf(m, "%s %u",
3664                   mod->name, mod->init_size + mod->core_size);
3665        print_unload_info(m, mod);
3666
3667        /* Informative for users. */
3668        seq_printf(m, " %s",
3669                   mod->state == MODULE_STATE_GOING ? "Unloading":
3670                   mod->state == MODULE_STATE_COMING ? "Loading":
3671                   "Live");
3672        /* Used by oprofile and other similar tools. */
3673        seq_printf(m, " 0x%pK", mod->module_core);
3674
3675        /* Taints info */
3676        if (mod->taints)
3677                seq_printf(m, " %s", module_flags(mod, buf));
3678
3679        seq_printf(m, "\n");
3680        return 0;
3681}
3682
3683/* Format: modulename size refcount deps address
3684
3685   Where refcount is a number or -, and deps is a comma-separated list
3686   of depends or -.
3687*/
3688static const struct seq_operations modules_op = {
3689        .start  = m_start,
3690        .next   = m_next,
3691        .stop   = m_stop,
3692        .show   = m_show
3693};
3694
3695static int modules_open(struct inode *inode, struct file *file)
3696{
3697        return seq_open(file, &modules_op);
3698}
3699
3700static const struct file_operations proc_modules_operations = {
3701        .open           = modules_open,
3702        .read           = seq_read,
3703        .llseek         = seq_lseek,
3704        .release        = seq_release,
3705};
3706
3707static int __init proc_modules_init(void)
3708{
3709        proc_create("modules", 0, NULL, &proc_modules_operations);
3710        return 0;
3711}
3712module_init(proc_modules_init);
3713#endif
3714
3715/* Given an address, look for it in the module exception tables. */
3716const struct exception_table_entry *search_module_extables(unsigned long addr)
3717{
3718        const struct exception_table_entry *e = NULL;
3719        struct module *mod;
3720
3721        preempt_disable();
3722        list_for_each_entry_rcu(mod, &modules, list) {
3723                if (mod->state == MODULE_STATE_UNFORMED)
3724                        continue;
3725                if (mod->num_exentries == 0)
3726                        continue;
3727
3728                e = search_extable(mod->extable,
3729                                   mod->extable + mod->num_exentries - 1,
3730                                   addr);
3731                if (e)
3732                        break;
3733        }
3734        preempt_enable();
3735
3736        /* Now, if we found one, we are running inside it now, hence
3737           we cannot unload the module, hence no refcnt needed. */
3738        return e;
3739}
3740
3741/*
3742 * is_module_address - is this address inside a module?
3743 * @addr: the address to check.
3744 *
3745 * See is_module_text_address() if you simply want to see if the address
3746 * is code (not data).
3747 */
3748bool is_module_address(unsigned long addr)
3749{
3750        bool ret;
3751
3752        preempt_disable();
3753        ret = __module_address(addr) != NULL;
3754        preempt_enable();
3755
3756        return ret;
3757}
3758
3759/*
3760 * __module_address - get the module which contains an address.
3761 * @addr: the address.
3762 *
3763 * Must be called with preempt disabled or module mutex held so that
3764 * module doesn't get freed during this.
3765 */
3766struct module *__module_address(unsigned long addr)
3767{
3768        struct module *mod;
3769
3770        if (addr < module_addr_min || addr > module_addr_max)
3771                return NULL;
3772
3773        list_for_each_entry_rcu(mod, &modules, list) {
3774                if (mod->state == MODULE_STATE_UNFORMED)
3775                        continue;
3776                if (within_module_core(addr, mod)
3777                    || within_module_init(addr, mod))
3778                        return mod;
3779        }
3780        return NULL;
3781}
3782EXPORT_SYMBOL_GPL(__module_address);
3783
3784/*
3785 * is_module_text_address - is this address inside module code?
3786 * @addr: the address to check.
3787 *
3788 * See is_module_address() if you simply want to see if the address is
3789 * anywhere in a module.  See kernel_text_address() for testing if an
3790 * address corresponds to kernel or module code.
3791 */
3792bool is_module_text_address(unsigned long addr)
3793{
3794        bool ret;
3795
3796        preempt_disable();
3797        ret = __module_text_address(addr) != NULL;
3798        preempt_enable();
3799
3800        return ret;
3801}
3802
3803/*
3804 * __module_text_address - get the module whose code contains an address.
3805 * @addr: the address.
3806 *
3807 * Must be called with preempt disabled or module mutex held so that
3808 * module doesn't get freed during this.
3809 */
3810struct module *__module_text_address(unsigned long addr)
3811{
3812        struct module *mod = __module_address(addr);
3813        if (mod) {
3814                /* Make sure it's within the text section. */
3815                if (!within(addr, mod->module_init, mod->init_text_size)
3816                    && !within(addr, mod->module_core, mod->core_text_size))
3817                        mod = NULL;
3818        }
3819        return mod;
3820}
3821EXPORT_SYMBOL_GPL(__module_text_address);
3822
3823/* Don't grab lock, we're oopsing. */
3824void print_modules(void)
3825{
3826        struct module *mod;
3827        char buf[8];
3828
3829        printk(KERN_DEFAULT "Modules linked in:");
3830        /* Most callers should already have preempt disabled, but make sure */
3831        preempt_disable();
3832        list_for_each_entry_rcu(mod, &modules, list) {
3833                if (mod->state == MODULE_STATE_UNFORMED)
3834                        continue;
3835                printk(" %s%s", mod->name, module_flags(mod, buf));
3836        }
3837        preempt_enable();
3838        if (last_unloaded_module[0])
3839                printk(" [last unloaded: %s]", last_unloaded_module);
3840        printk("\n");
3841}
3842
3843#ifdef CONFIG_MODVERSIONS
3844/* Generate the signature for all relevant module structures here.
3845 * If these change, we don't want to try to parse the module. */
3846void module_layout(struct module *mod,
3847                   struct modversion_info *ver,
3848                   struct kernel_param *kp,
3849                   struct kernel_symbol *ks,
3850                   struct tracepoint * const *tp)
3851{
3852}
3853EXPORT_SYMBOL(module_layout);
3854#endif
3855
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