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