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/fs.h>
  25#include <linux/sysfs.h>
  26#include <linux/kernel.h>
  27#include <linux/slab.h>
  28#include <linux/vmalloc.h>
  29#include <linux/elf.h>
  30#include <linux/proc_fs.h>
  31#include <linux/seq_file.h>
  32#include <linux/syscalls.h>
  33#include <linux/fcntl.h>
  34#include <linux/rcupdate.h>
  35#include <linux/capability.h>
  36#include <linux/cpu.h>
  37#include <linux/moduleparam.h>
  38#include <linux/errno.h>
  39#include <linux/err.h>
  40#include <linux/vermagic.h>
  41#include <linux/notifier.h>
  42#include <linux/sched.h>
  43#include <linux/stop_machine.h>
  44#include <linux/device.h>
  45#include <linux/string.h>
  46#include <linux/mutex.h>
  47#include <linux/rculist.h>
  48#include <asm/uaccess.h>
  49#include <asm/cacheflush.h>
  50#include <asm/mmu_context.h>
  51#include <linux/license.h>
  52#include <asm/sections.h>
  53#include <linux/tracepoint.h>
  54#include <linux/ftrace.h>
  55#include <linux/async.h>
  56#include <linux/percpu.h>
  57#include <linux/kmemleak.h>
  58#include <linux/jump_label.h>
  59#include <linux/pfn.h>
  60#include <linux/bsearch.h>
  61#include <linux/fips.h>
  62#include "module-internal.h"
  63
  64#define CREATE_TRACE_POINTS
  65#include <trace/events/module.h>
  66
  67#ifndef ARCH_SHF_SMALL
  68#define ARCH_SHF_SMALL 0
  69#endif
  70
  71/*
  72 * Modules' sections will be aligned on page boundaries
  73 * to ensure complete separation of code and data, but
  74 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
  75 */
  76#ifdef CONFIG_DEBUG_SET_MODULE_RONX
  77# define debug_align(X) ALIGN(X, PAGE_SIZE)
  78#else
  79# define debug_align(X) (X)
  80#endif
  81
  82/*
  83 * Given BASE and SIZE this macro calculates the number of pages the
  84 * memory regions occupies
  85 */
  86#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?         \
  87                (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
  88                         PFN_DOWN((unsigned long)BASE) + 1)     \
  89                : (0UL))
  90
  91/* If this is set, the section belongs in the init part of the module */
  92#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
  93
  94/*
  95 * Mutex protects:
  96 * 1) List of modules (also safely readable with preempt_disable),
  97 * 2) module_use links,
  98 * 3) module_addr_min/module_addr_max.
  99 * (delete uses stop_machine/add uses RCU list operations). */
 100DEFINE_MUTEX(module_mutex);
 101EXPORT_SYMBOL_GPL(module_mutex);
 102static LIST_HEAD(modules);
 103#ifdef CONFIG_KGDB_KDB
 104struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
 105#endif /* CONFIG_KGDB_KDB */
 106
 107#ifdef CONFIG_MODULE_SIG
 108#ifdef CONFIG_MODULE_SIG_FORCE
 109static bool sig_enforce = true;
 110#else
 111static bool sig_enforce = false;
 112
 113static int param_set_bool_enable_only(const char *val,
 114                                      const struct kernel_param *kp)
 115{
 116        int err;
 117        bool test;
 118        struct kernel_param dummy_kp = *kp;
 119
 120        dummy_kp.arg = &test;
 121
 122        err = param_set_bool(val, &dummy_kp);
 123        if (err)
 124                return err;
 125
 126        /* Don't let them unset it once it's set! */
 127        if (!test && sig_enforce)
 128                return -EROFS;
 129
 130        if (test)
 131                sig_enforce = true;
 132        return 0;
 133}
 134
 135static const struct kernel_param_ops param_ops_bool_enable_only = {
 136        .set = param_set_bool_enable_only,
 137        .get = param_get_bool,
 138};
 139#define param_check_bool_enable_only param_check_bool
 140
 141module_param(sig_enforce, bool_enable_only, 0644);
 142#endif /* !CONFIG_MODULE_SIG_FORCE */
 143#endif /* CONFIG_MODULE_SIG */
 144
 145/* Block module loading/unloading? */
 146int modules_disabled = 0;
 147core_param(nomodule, modules_disabled, bint, 0);
 148
 149/* Waiting for a module to finish initializing? */
 150static DECLARE_WAIT_QUEUE_HEAD(module_wq);
 151
 152static BLOCKING_NOTIFIER_HEAD(module_notify_list);
 153
 154/* Bounds of module allocation, for speeding __module_address.
 155 * Protected by module_mutex. */
 156static unsigned long module_addr_min = -1UL, module_addr_max = 0;
 157
 158int register_module_notifier(struct notifier_block * nb)
 159{
 160        return blocking_notifier_chain_register(&module_notify_list, nb);
 161}
 162EXPORT_SYMBOL(register_module_notifier);
 163
 164int unregister_module_notifier(struct notifier_block * nb)
 165{
 166        return blocking_notifier_chain_unregister(&module_notify_list, nb);
 167}
 168EXPORT_SYMBOL(unregister_module_notifier);
 169
 170struct load_info {
 171        Elf_Ehdr *hdr;
 172        unsigned long len;
 173        Elf_Shdr *sechdrs;
 174        char *secstrings, *strtab;
 175        unsigned long symoffs, stroffs;
 176        struct _ddebug *debug;
 177        unsigned int num_debug;
 178        bool sig_ok;
 179        struct {
 180                unsigned int sym, str, mod, vers, info, pcpu;
 181        } index;
 182};
 183
 184/* We require a truly strong try_module_get(): 0 means failure due to
 185   ongoing or failed initialization etc. */
 186static inline int strong_try_module_get(struct module *mod)
 187{
 188        if (mod && mod->state == MODULE_STATE_COMING)
 189                return -EBUSY;
 190        if (try_module_get(mod))
 191                return 0;
 192        else
 193                return -ENOENT;
 194}
 195
 196static inline void add_taint_module(struct module *mod, unsigned flag)
 197{
 198        add_taint(flag);
 199        mod->taints |= (1U << flag);
 200}
 201
 202/*
 203 * A thread that wants to hold a reference to a module only while it
 204 * is running can call this to safely exit.  nfsd and lockd use this.
 205 */
 206void __module_put_and_exit(struct module *mod, long code)
 207{
 208        module_put(mod);
 209        do_exit(code);
 210}
 211EXPORT_SYMBOL(__module_put_and_exit);
 212
 213/* Find a module section: 0 means not found. */
 214static unsigned int find_sec(const struct load_info *info, const char *name)
 215{
 216        unsigned int i;
 217
 218        for (i = 1; i < info->hdr->e_shnum; i++) {
 219                Elf_Shdr *shdr = &info->sechdrs[i];
 220                /* Alloc bit cleared means "ignore it." */
 221                if ((shdr->sh_flags & SHF_ALLOC)
 222                    && strcmp(info->secstrings + shdr->sh_name, name) == 0)
 223                        return i;
 224        }
 225        return 0;
 226}
 227
 228/* Find a module section, or NULL. */
 229static void *section_addr(const struct load_info *info, const char *name)
 230{
 231        /* Section 0 has sh_addr 0. */
 232        return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
 233}
 234
 235/* Find a module section, or NULL.  Fill in number of "objects" in section. */
 236static void *section_objs(const struct load_info *info,
 237                          const char *name,
 238                          size_t object_size,
 239                          unsigned int *num)
 240{
 241        unsigned int sec = find_sec(info, name);
 242
 243        /* Section 0 has sh_addr 0 and sh_size 0. */
 244        *num = info->sechdrs[sec].sh_size / object_size;
 245        return (void *)info->sechdrs[sec].sh_addr;
 246}
 247
 248/* Provided by the linker */
 249extern const struct kernel_symbol __start___ksymtab[];
 250extern const struct kernel_symbol __stop___ksymtab[];
 251extern const struct kernel_symbol __start___ksymtab_gpl[];
 252extern const struct kernel_symbol __stop___ksymtab_gpl[];
 253extern const struct kernel_symbol __start___ksymtab_gpl_future[];
 254extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
 255extern const unsigned long __start___kcrctab[];
 256extern const unsigned long __start___kcrctab_gpl[];
 257extern const unsigned long __start___kcrctab_gpl_future[];
 258#ifdef CONFIG_UNUSED_SYMBOLS
 259extern const struct kernel_symbol __start___ksymtab_unused[];
 260extern const struct kernel_symbol __stop___ksymtab_unused[];
 261extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
 262extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
 263extern const unsigned long __start___kcrctab_unused[];
 264extern const unsigned long __start___kcrctab_unused_gpl[];
 265#endif
 266
 267#ifndef CONFIG_MODVERSIONS
 268#define symversion(base, idx) NULL
 269#else
 270#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
 271#endif
 272
 273static bool each_symbol_in_section(const struct symsearch *arr,
 274                                   unsigned int arrsize,
 275                                   struct module *owner,
 276                                   bool (*fn)(const struct symsearch *syms,
 277                                              struct module *owner,
 278                                              void *data),
 279                                   void *data)
 280{
 281        unsigned int j;
 282
 283        for (j = 0; j < arrsize; j++) {
 284                if (fn(&arr[j], owner, data))
 285                        return true;
 286        }
 287
 288        return false;
 289}
 290
 291/* Returns true as soon as fn returns true, otherwise false. */
 292bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 293                                    struct module *owner,
 294                                    void *data),
 295                         void *data)
 296{
 297        struct module *mod;
 298        static const struct symsearch arr[] = {
 299                { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
 300                  NOT_GPL_ONLY, false },
 301                { __start___ksymtab_gpl, __stop___ksymtab_gpl,
 302                  __start___kcrctab_gpl,
 303                  GPL_ONLY, false },
 304                { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
 305                  __start___kcrctab_gpl_future,
 306                  WILL_BE_GPL_ONLY, false },
 307#ifdef CONFIG_UNUSED_SYMBOLS
 308                { __start___ksymtab_unused, __stop___ksymtab_unused,
 309                  __start___kcrctab_unused,
 310                  NOT_GPL_ONLY, true },
 311                { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
 312                  __start___kcrctab_unused_gpl,
 313                  GPL_ONLY, true },
 314#endif
 315        };
 316
 317        if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
 318                return true;
 319
 320        list_for_each_entry_rcu(mod, &modules, list) {
 321                struct symsearch arr[] = {
 322                        { mod->syms, mod->syms + mod->num_syms, mod->crcs,
 323                          NOT_GPL_ONLY, false },
 324                        { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
 325                          mod->gpl_crcs,
 326                          GPL_ONLY, false },
 327                        { mod->gpl_future_syms,
 328                          mod->gpl_future_syms + mod->num_gpl_future_syms,
 329                          mod->gpl_future_crcs,
 330                          WILL_BE_GPL_ONLY, false },
 331#ifdef CONFIG_UNUSED_SYMBOLS
 332                        { mod->unused_syms,
 333                          mod->unused_syms + mod->num_unused_syms,
 334                          mod->unused_crcs,
 335                          NOT_GPL_ONLY, true },
 336                        { mod->unused_gpl_syms,
 337                          mod->unused_gpl_syms + mod->num_unused_gpl_syms,
 338                          mod->unused_gpl_crcs,
 339                          GPL_ONLY, true },
 340#endif
 341                };
 342
 343                if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
 344                        return true;
 345        }
 346        return false;
 347}
 348EXPORT_SYMBOL_GPL(each_symbol_section);
 349
 350struct find_symbol_arg {
 351        /* Input */
 352        const char *name;
 353        bool gplok;
 354        bool warn;
 355
 356        /* Output */
 357        struct module *owner;
 358        const unsigned long *crc;
 359        const struct kernel_symbol *sym;
 360};
 361
 362static bool check_symbol(const struct symsearch *syms,
 363                                 struct module *owner,
 364                                 unsigned int symnum, void *data)
 365{
 366        struct find_symbol_arg *fsa = data;
 367
 368        if (!fsa->gplok) {
 369                if (syms->licence == GPL_ONLY)
 370                        return false;
 371                if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
 372                        printk(KERN_WARNING "Symbol %s is being used "
 373                               "by a non-GPL module, which will not "
 374                               "be allowed in the future\n", fsa->name);
 375                        printk(KERN_WARNING "Please see the file "
 376                               "Documentation/feature-removal-schedule.txt "
 377                               "in the kernel source tree for more details.\n");
 378                }
 379        }
 380
 381#ifdef CONFIG_UNUSED_SYMBOLS
 382        if (syms->unused && fsa->warn) {
 383                printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
 384                       "however this module is using it.\n", fsa->name);
 385                printk(KERN_WARNING
 386                       "This symbol will go away in the future.\n");
 387                printk(KERN_WARNING
 388                       "Please evalute if this is the right api to use and if "
 389                       "it really is, submit a report the linux kernel "
 390                       "mailinglist together with submitting your code for "
 391                       "inclusion.\n");
 392        }
 393#endif
 394
 395        fsa->owner = owner;
 396        fsa->crc = symversion(syms->crcs, symnum);
 397        fsa->sym = &syms->start[symnum];
 398        return true;
 399}
 400
 401static int cmp_name(const void *va, const void *vb)
 402{
 403        const char *a;
 404        const struct kernel_symbol *b;
 405        a = va; b = vb;
 406        return strcmp(a, b->name);
 407}
 408
 409static bool find_symbol_in_section(const struct symsearch *syms,
 410                                   struct module *owner,
 411                                   void *data)
 412{
 413        struct find_symbol_arg *fsa = data;
 414        struct kernel_symbol *sym;
 415
 416        sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
 417                        sizeof(struct kernel_symbol), cmp_name);
 418
 419        if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
 420                return true;
 421
 422        return false;
 423}
 424
 425/* Find a symbol and return it, along with, (optional) crc and
 426 * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
 427const struct kernel_symbol *find_symbol(const char *name,
 428                                        struct module **owner,
 429                                        const unsigned long **crc,
 430                                        bool gplok,
 431                                        bool warn)
 432{
 433        struct find_symbol_arg fsa;
 434
 435        fsa.name = name;
 436        fsa.gplok = gplok;
 437        fsa.warn = warn;
 438
 439        if (each_symbol_section(find_symbol_in_section, &fsa)) {
 440                if (owner)
 441                        *owner = fsa.owner;
 442                if (crc)
 443                        *crc = fsa.crc;
 444                return fsa.sym;
 445        }
 446
 447        pr_debug("Failed to find symbol %s\n", name);
 448        return NULL;
 449}
 450EXPORT_SYMBOL_GPL(find_symbol);
 451
 452/* Search for module by name: must hold module_mutex. */
 453struct module *find_module(const char *name)
 454{
 455        struct module *mod;
 456
 457        list_for_each_entry(mod, &modules, list) {
 458                if (strcmp(mod->name, name) == 0)
 459                        return mod;
 460        }
 461        return NULL;
 462}
 463EXPORT_SYMBOL_GPL(find_module);
 464
 465#ifdef CONFIG_SMP
 466
 467static inline void __percpu *mod_percpu(struct module *mod)
 468{
 469        return mod->percpu;
 470}
 471
 472static int percpu_modalloc(struct module *mod,
 473                           unsigned long size, unsigned long align)
 474{
 475        if (align > PAGE_SIZE) {
 476                printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
 477                       mod->name, align, PAGE_SIZE);
 478                align = PAGE_SIZE;
 479        }
 480
 481        mod->percpu = __alloc_reserved_percpu(size, align);
 482        if (!mod->percpu) {
 483                printk(KERN_WARNING
 484                       "%s: Could not allocate %lu bytes percpu data\n",
 485                       mod->name, size);
 486                return -ENOMEM;
 487        }
 488        mod->percpu_size = size;
 489        return 0;
 490}
 491
 492static void percpu_modfree(struct module *mod)
 493{
 494        free_percpu(mod->percpu);
 495}
 496
 497static unsigned int find_pcpusec(struct load_info *info)
 498{
 499        return find_sec(info, ".data..percpu");
 500}
 501
 502static void percpu_modcopy(struct module *mod,
 503                           const void *from, unsigned long size)
 504{
 505        int cpu;
 506
 507        for_each_possible_cpu(cpu)
 508                memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
 509}
 510
 511/**
 512 * is_module_percpu_address - test whether address is from module static percpu
 513 * @addr: address to test
 514 *
 515 * Test whether @addr belongs to module static percpu area.
 516 *
 517 * RETURNS:
 518 * %true if @addr is from module static percpu area
 519 */
 520bool is_module_percpu_address(unsigned long addr)
 521{
 522        struct module *mod;
 523        unsigned int cpu;
 524
 525        preempt_disable();
 526
 527        list_for_each_entry_rcu(mod, &modules, list) {
 528                if (!mod->percpu_size)
 529                        continue;
 530                for_each_possible_cpu(cpu) {
 531                        void *start = per_cpu_ptr(mod->percpu, cpu);
 532
 533                        if ((void *)addr >= start &&
 534                            (void *)addr < start + mod->percpu_size) {
 535                                preempt_enable();
 536                                return true;
 537                        }
 538                }
 539        }
 540
 541        preempt_enable();
 542        return false;
 543}
 544
 545#else /* ... !CONFIG_SMP */
 546
 547static inline void __percpu *mod_percpu(struct module *mod)
 548{
 549        return NULL;
 550}
 551static inline int percpu_modalloc(struct module *mod,
 552                                  unsigned long size, unsigned long align)
 553{
 554        return -ENOMEM;
 555}
 556static inline void percpu_modfree(struct module *mod)
 557{
 558}
 559static unsigned int find_pcpusec(struct load_info *info)
 560{
 561        return 0;
 562}
 563static inline void percpu_modcopy(struct module *mod,
 564                                  const void *from, unsigned long size)
 565{
 566        /* pcpusec should be 0, and size of that section should be 0. */
 567        BUG_ON(size != 0);
 568}
 569bool is_module_percpu_address(unsigned long addr)
 570{
 571        return false;
 572}
 573
 574#endif /* CONFIG_SMP */
 575
 576#define MODINFO_ATTR(field)     \
 577static void setup_modinfo_##field(struct module *mod, const char *s)  \
 578{                                                                     \
 579        mod->field = kstrdup(s, GFP_KERNEL);                          \
 580}                                                                     \
 581static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
 582                        struct module_kobject *mk, char *buffer)      \
 583{                                                                     \
 584        return sprintf(buffer, "%s\n", mk->mod->field);               \
 585}                                                                     \
 586static int modinfo_##field##_exists(struct module *mod)               \
 587{                                                                     \
 588        return mod->field != NULL;                                    \
 589}                                                                     \
 590static void free_modinfo_##field(struct module *mod)                  \
 591{                                                                     \
 592        kfree(mod->field);                                            \
 593        mod->field = NULL;                                            \
 594}                                                                     \
 595static struct module_attribute modinfo_##field = {                    \
 596        .attr = { .name = __stringify(field), .mode = 0444 },         \
 597        .show = show_modinfo_##field,                                 \
 598        .setup = setup_modinfo_##field,                               \
 599        .test = modinfo_##field##_exists,                             \
 600        .free = free_modinfo_##field,                                 \
 601};
 602
 603MODINFO_ATTR(version);
 604MODINFO_ATTR(srcversion);
 605
 606static char last_unloaded_module[MODULE_NAME_LEN+1];
 607
 608#ifdef CONFIG_MODULE_UNLOAD
 609
 610EXPORT_TRACEPOINT_SYMBOL(module_get);
 611
 612/* Init the unload section of the module. */
 613static int module_unload_init(struct module *mod)
 614{
 615        mod->refptr = alloc_percpu(struct module_ref);
 616        if (!mod->refptr)
 617                return -ENOMEM;
 618
 619        INIT_LIST_HEAD(&mod->source_list);
 620        INIT_LIST_HEAD(&mod->target_list);
 621
 622        /* Hold reference count during initialization. */
 623        __this_cpu_write(mod->refptr->incs, 1);
 624        /* Backwards compatibility macros put refcount during init. */
 625        mod->waiter = current;
 626
 627        return 0;
 628}
 629
 630/* Does a already use b? */
 631static int already_uses(struct module *a, struct module *b)
 632{
 633        struct module_use *use;
 634
 635        list_for_each_entry(use, &b->source_list, source_list) {
 636                if (use->source == a) {
 637                        pr_debug("%s uses %s!\n", a->name, b->name);
 638                        return 1;
 639                }
 640        }
 641        pr_debug("%s does not use %s!\n", a->name, b->name);
 642        return 0;
 643}
 644
 645/*
 646 * Module a uses b
 647 *  - we add 'a' as a "source", 'b' as a "target" of module use
 648 *  - the module_use is added to the list of 'b' sources (so
 649 *    'b' can walk the list to see who sourced them), and of 'a'
 650 *    targets (so 'a' can see what modules it targets).
 651 */
 652static int add_module_usage(struct module *a, struct module *b)
 653{
 654        struct module_use *use;
 655
 656        pr_debug("Allocating new usage for %s.\n", a->name);
 657        use = kmalloc(sizeof(*use), GFP_ATOMIC);
 658        if (!use) {
 659                printk(KERN_WARNING "%s: out of memory loading\n", a->name);
 660                return -ENOMEM;
 661        }
 662
 663        use->source = a;
 664        use->target = b;
 665        list_add(&use->source_list, &b->source_list);
 666        list_add(&use->target_list, &a->target_list);
 667        return 0;
 668}
 669
 670/* Module a uses b: caller needs module_mutex() */
 671int ref_module(struct module *a, struct module *b)
 672{
 673        int err;
 674
 675        if (b == NULL || already_uses(a, b))
 676                return 0;
 677
 678        /* If module isn't available, we fail. */
 679        err = strong_try_module_get(b);
 680        if (err)
 681                return err;
 682
 683        err = add_module_usage(a, b);
 684        if (err) {
 685                module_put(b);
 686                return err;
 687        }
 688        return 0;
 689}
 690EXPORT_SYMBOL_GPL(ref_module);
 691
 692/* Clear the unload stuff of the module. */
 693static void module_unload_free(struct module *mod)
 694{
 695        struct module_use *use, *tmp;
 696
 697        mutex_lock(&module_mutex);
 698        list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
 699                struct module *i = use->target;
 700                pr_debug("%s unusing %s\n", mod->name, i->name);
 701                module_put(i);
 702                list_del(&use->source_list);
 703                list_del(&use->target_list);
 704                kfree(use);
 705        }
 706        mutex_unlock(&module_mutex);
 707
 708        free_percpu(mod->refptr);
 709}
 710
 711#ifdef CONFIG_MODULE_FORCE_UNLOAD
 712static inline int try_force_unload(unsigned int flags)
 713{
 714        int ret = (flags & O_TRUNC);
 715        if (ret)
 716                add_taint(TAINT_FORCED_RMMOD);
 717        return ret;
 718}
 719#else
 720static inline int try_force_unload(unsigned int flags)
 721{
 722        return 0;
 723}
 724#endif /* CONFIG_MODULE_FORCE_UNLOAD */
 725
 726struct stopref
 727{
 728        struct module *mod;
 729        int flags;
 730        int *forced;
 731};
 732
 733/* Whole machine is stopped with interrupts off when this runs. */
 734static int __try_stop_module(void *_sref)
 735{
 736        struct stopref *sref = _sref;
 737
 738        /* If it's not unused, quit unless we're forcing. */
 739        if (module_refcount(sref->mod) != 0) {
 740                if (!(*sref->forced = try_force_unload(sref->flags)))
 741                        return -EWOULDBLOCK;
 742        }
 743
 744        /* Mark it as dying. */
 745        sref->mod->state = MODULE_STATE_GOING;
 746        return 0;
 747}
 748
 749static int try_stop_module(struct module *mod, int flags, int *forced)
 750{
 751        if (flags & O_NONBLOCK) {
 752                struct stopref sref = { mod, flags, forced };
 753
 754                return stop_machine(__try_stop_module, &sref, NULL);
 755        } else {
 756                /* We don't need to stop the machine for this. */
 757                mod->state = MODULE_STATE_GOING;
 758                synchronize_sched();
 759                return 0;
 760        }
 761}
 762
 763unsigned long module_refcount(struct module *mod)
 764{
 765        unsigned long incs = 0, decs = 0;
 766        int cpu;
 767
 768        for_each_possible_cpu(cpu)
 769                decs += per_cpu_ptr(mod->refptr, cpu)->decs;
 770        /*
 771         * ensure the incs are added up after the decs.
 772         * module_put ensures incs are visible before decs with smp_wmb.
 773         *
 774         * This 2-count scheme avoids the situation where the refcount
 775         * for CPU0 is read, then CPU0 increments the module refcount,
 776         * then CPU1 drops that refcount, then the refcount for CPU1 is
 777         * read. We would record a decrement but not its corresponding
 778         * increment so we would see a low count (disaster).
 779         *
 780         * Rare situation? But module_refcount can be preempted, and we
 781         * might be tallying up 4096+ CPUs. So it is not impossible.
 782         */
 783        smp_rmb();
 784        for_each_possible_cpu(cpu)
 785                incs += per_cpu_ptr(mod->refptr, cpu)->incs;
 786        return incs - decs;
 787}
 788EXPORT_SYMBOL(module_refcount);
 789
 790/* This exists whether we can unload or not */
 791static void free_module(struct module *mod);
 792
 793static void wait_for_zero_refcount(struct module *mod)
 794{
 795        /* Since we might sleep for some time, release the mutex first */
 796        mutex_unlock(&module_mutex);
 797        for (;;) {
 798                pr_debug("Looking at refcount...\n");
 799                set_current_state(TASK_UNINTERRUPTIBLE);
 800                if (module_refcount(mod) == 0)
 801                        break;
 802                schedule();
 803        }
 804        current->state = TASK_RUNNING;
 805        mutex_lock(&module_mutex);
 806}
 807
 808SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
 809                unsigned int, flags)
 810{
 811        struct module *mod;
 812        char name[MODULE_NAME_LEN];
 813        int ret, forced = 0;
 814
 815        if (!capable(CAP_SYS_MODULE) || modules_disabled)
 816                return -EPERM;
 817
 818        if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
 819                return -EFAULT;
 820        name[MODULE_NAME_LEN-1] = '\0';
 821
 822        if (mutex_lock_interruptible(&module_mutex) != 0)
 823                return -EINTR;
 824
 825        mod = find_module(name);
 826        if (!mod) {
 827                ret = -ENOENT;
 828                goto out;
 829        }
 830
 831        if (!list_empty(&mod->source_list)) {
 832                /* Other modules depend on us: get rid of them first. */
 833                ret = -EWOULDBLOCK;
 834                goto out;
 835        }
 836
 837        /* Doing init or already dying? */
 838        if (mod->state != MODULE_STATE_LIVE) {
 839                /* FIXME: if (force), slam module count and wake up
 840                   waiter --RR */
 841                pr_debug("%s already dying\n", mod->name);
 842                ret = -EBUSY;
 843                goto out;
 844        }
 845
 846        /* If it has an init func, it must have an exit func to unload */
 847        if (mod->init && !mod->exit) {
 848                forced = try_force_unload(flags);
 849                if (!forced) {
 850                        /* This module can't be removed */
 851                        ret = -EBUSY;
 852                        goto out;
 853                }
 854        }
 855
 856        /* Set this up before setting mod->state */
 857        mod->waiter = current;
 858
 859        /* Stop the machine so refcounts can't move and disable module. */
 860        ret = try_stop_module(mod, flags, &forced);
 861        if (ret != 0)
 862                goto out;
 863
 864        /* Never wait if forced. */
 865        if (!forced && module_refcount(mod) != 0)
 866                wait_for_zero_refcount(mod);
 867
 868        mutex_unlock(&module_mutex);
 869        /* Final destruction now no one is using it. */
 870        if (mod->exit != NULL)
 871                mod->exit();
 872        blocking_notifier_call_chain(&module_notify_list,
 873                                     MODULE_STATE_GOING, mod);
 874        async_synchronize_full();
 875
 876        /* Store the name of the last unloaded module for diagnostic purposes */
 877        strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
 878
 879        free_module(mod);
 880        return 0;
 881out:
 882        mutex_unlock(&module_mutex);
 883        return ret;
 884}
 885
 886static inline void print_unload_info(struct seq_file *m, struct module *mod)
 887{
 888        struct module_use *use;
 889        int printed_something = 0;
 890
 891        seq_printf(m, " %lu ", module_refcount(mod));
 892
 893        /* Always include a trailing , so userspace can differentiate
 894           between this and the old multi-field proc format. */
 895        list_for_each_entry(use, &mod->source_list, source_list) {
 896                printed_something = 1;
 897                seq_printf(m, "%s,", use->source->name);
 898        }
 899
 900        if (mod->init != NULL && mod->exit == NULL) {
 901                printed_something = 1;
 902                seq_printf(m, "[permanent],");
 903        }
 904
 905        if (!printed_something)
 906                seq_printf(m, "-");
 907}
 908
 909void __symbol_put(const char *symbol)
 910{
 911        struct module *owner;
 912
 913        preempt_disable();
 914        if (!find_symbol(symbol, &owner, NULL, true, false))
 915                BUG();
 916        module_put(owner);
 917        preempt_enable();
 918}
 919EXPORT_SYMBOL(__symbol_put);
 920
 921/* Note this assumes addr is a function, which it currently always is. */
 922void symbol_put_addr(void *addr)
 923{
 924        struct module *modaddr;
 925        unsigned long a = (unsigned long)dereference_function_descriptor(addr);
 926
 927        if (core_kernel_text(a))
 928                return;
 929
 930        /* module_text_address is safe here: we're supposed to have reference
 931         * to module from symbol_get, so it can't go away. */
 932        modaddr = __module_text_address(a);
 933        BUG_ON(!modaddr);
 934        module_put(modaddr);
 935}
 936EXPORT_SYMBOL_GPL(symbol_put_addr);
 937
 938static ssize_t show_refcnt(struct module_attribute *mattr,
 939                           struct module_kobject *mk, char *buffer)
 940{
 941        return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
 942}
 943
 944static struct module_attribute modinfo_refcnt =
 945        __ATTR(refcnt, 0444, show_refcnt, NULL);
 946
 947void __module_get(struct module *module)
 948{
 949        if (module) {
 950                preempt_disable();
 951                __this_cpu_inc(module->refptr->incs);
 952                trace_module_get(module, _RET_IP_);
 953                preempt_enable();
 954        }
 955}
 956EXPORT_SYMBOL(__module_get);
 957
 958bool try_module_get(struct module *module)
 959{
 960        bool ret = true;
 961
 962        if (module) {
 963                preempt_disable();
 964
 965                if (likely(module_is_live(module))) {
 966                        __this_cpu_inc(module->refptr->incs);
 967                        trace_module_get(module, _RET_IP_);
 968                } else
 969                        ret = false;
 970
 971                preempt_enable();
 972        }
 973        return ret;
 974}
 975EXPORT_SYMBOL(try_module_get);
 976
 977void module_put(struct module *module)
 978{
 979        if (module) {
 980                preempt_disable();
 981                smp_wmb(); /* see comment in module_refcount */
 982                __this_cpu_inc(module->refptr->decs);
 983
 984                trace_module_put(module, _RET_IP_);
 985                /* Maybe they're waiting for us to drop reference? */
 986                if (unlikely(!module_is_live(module)))
 987                        wake_up_process(module->waiter);
 988                preempt_enable();
 989        }
 990}
 991EXPORT_SYMBOL(module_put);
 992
 993#else /* !CONFIG_MODULE_UNLOAD */
 994static inline void print_unload_info(struct seq_file *m, struct module *mod)
 995{
 996        /* We don't know the usage count, or what modules are using. */
 997        seq_printf(m, " - -");
 998}
 999
1000static inline void module_unload_free(struct module *mod)
1001{
1002}
1003
1004int ref_module(struct module *a, struct module *b)
1005{
1006        return strong_try_module_get(b);
1007}
1008EXPORT_SYMBOL_GPL(ref_module);
1009
1010static inline int module_unload_init(struct module *mod)
1011{
1012        return 0;
1013}
1014#endif /* CONFIG_MODULE_UNLOAD */
1015
1016static size_t module_flags_taint(struct module *mod, char *buf)
1017{
1018        size_t l = 0;
1019
1020        if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1021                buf[l++] = 'P';
1022        if (mod->taints & (1 << TAINT_OOT_MODULE))
1023                buf[l++] = 'O';
1024        if (mod->taints & (1 << TAINT_FORCED_MODULE))
1025                buf[l++] = 'F';
1026        if (mod->taints & (1 << TAINT_CRAP))
1027                buf[l++] = 'C';
1028        /*
1029         * TAINT_FORCED_RMMOD: could be added.
1030         * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1031         * apply to modules.
1032         */
1033        return l;
1034}
1035
1036static ssize_t show_initstate(struct module_attribute *mattr,
1037                              struct module_kobject *mk, char *buffer)
1038{
1039        const char *state = "unknown";
1040
1041        switch (mk->mod->state) {
1042        case MODULE_STATE_LIVE:
1043                state = "live";
1044                break;
1045        case MODULE_STATE_COMING:
1046                state = "coming";
1047                break;
1048        case MODULE_STATE_GOING:
1049                state = "going";
1050                break;
1051        }
1052        return sprintf(buffer, "%s\n", state);
1053}
1054
1055static struct module_attribute modinfo_initstate =
1056        __ATTR(initstate, 0444, show_initstate, NULL);
1057
1058static ssize_t store_uevent(struct module_attribute *mattr,
1059                            struct module_kobject *mk,
1060                            const char *buffer, size_t count)
1061{
1062        enum kobject_action action;
1063
1064        if (kobject_action_type(buffer, count, &action) == 0)
1065                kobject_uevent(&mk->kobj, action);
1066        return count;
1067}
1068
1069struct module_attribute module_uevent =
1070        __ATTR(uevent, 0200, NULL, store_uevent);
1071
1072static ssize_t show_coresize(struct module_attribute *mattr,
1073                             struct module_kobject *mk, char *buffer)
1074{
1075        return sprintf(buffer, "%u\n", mk->mod->core_size);
1076}
1077
1078static struct module_attribute modinfo_coresize =
1079        __ATTR(coresize, 0444, show_coresize, NULL);
1080
1081static ssize_t show_initsize(struct module_attribute *mattr,
1082                             struct module_kobject *mk, char *buffer)
1083{
1084        return sprintf(buffer, "%u\n", mk->mod->init_size);
1085}
1086
1087static struct module_attribute modinfo_initsize =
1088        __ATTR(initsize, 0444, show_initsize, NULL);
1089
1090static ssize_t show_taint(struct module_attribute *mattr,
1091                          struct module_kobject *mk, char *buffer)
1092{
1093        size_t l;
1094
1095        l = module_flags_taint(mk->mod, buffer);
1096        buffer[l++] = '\n';
1097        return l;
1098}
1099
1100static struct module_attribute modinfo_taint =
1101        __ATTR(taint, 0444, show_taint, NULL);
1102
1103static struct module_attribute *modinfo_attrs[] = {
1104        &module_uevent,
1105        &modinfo_version,
1106        &modinfo_srcversion,
1107        &modinfo_initstate,
1108        &modinfo_coresize,
1109        &modinfo_initsize,
1110        &modinfo_taint,
1111#ifdef CONFIG_MODULE_UNLOAD
1112        &modinfo_refcnt,
1113#endif
1114        NULL,
1115};
1116
1117static const char vermagic[] = VERMAGIC_STRING;
1118
1119static int try_to_force_load(struct module *mod, const char *reason)
1120{
1121#ifdef CONFIG_MODULE_FORCE_LOAD
1122        if (!test_taint(TAINT_FORCED_MODULE))
1123                printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1124                       mod->name, reason);
1125        add_taint_module(mod, TAINT_FORCED_MODULE);
1126        return 0;
1127#else
1128        return -ENOEXEC;
1129#endif
1130}
1131
1132#ifdef CONFIG_MODVERSIONS
1133/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1134static unsigned long maybe_relocated(unsigned long crc,
1135                                     const struct module *crc_owner)
1136{
1137#ifdef ARCH_RELOCATES_KCRCTAB
1138        if (crc_owner == NULL)
1139                return crc - (unsigned long)reloc_start;
1140#endif
1141        return crc;
1142}
1143
1144static int check_version(Elf_Shdr *sechdrs,
1145                         unsigned int versindex,
1146                         const char *symname,
1147                         struct module *mod, 
1148                         const unsigned long *crc,
1149                         const struct module *crc_owner)
1150{
1151        unsigned int i, num_versions;
1152        struct modversion_info *versions;
1153
1154        /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1155        if (!crc)
1156                return 1;
1157
1158        /* No versions at all?  modprobe --force does this. */
1159        if (versindex == 0)
1160                return try_to_force_load(mod, symname) == 0;
1161
1162        versions = (void *) sechdrs[versindex].sh_addr;
1163        num_versions = sechdrs[versindex].sh_size
1164                / sizeof(struct modversion_info);
1165
1166        for (i = 0; i < num_versions; i++) {
1167                if (strcmp(versions[i].name, symname) != 0)
1168                        continue;
1169
1170                if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1171                        return 1;
1172                pr_debug("Found checksum %lX vs module %lX\n",
1173                       maybe_relocated(*crc, crc_owner), versions[i].crc);
1174                goto bad_version;
1175        }
1176
1177        printk(KERN_WARNING "%s: no symbol version for %s\n",
1178               mod->name, symname);
1179        return 0;
1180
1181bad_version:
1182        printk("%s: disagrees about version of symbol %s\n",
1183               mod->name, symname);
1184        return 0;
1185}
1186
1187static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1188                                          unsigned int versindex,
1189                                          struct module *mod)
1190{
1191        const unsigned long *crc;
1192
1193        /* Since this should be found in kernel (which can't be removed),
1194         * no locking is necessary. */
1195        if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1196                         &crc, true, false))
1197                BUG();
1198        return check_version(sechdrs, versindex, "module_layout", mod, crc,
1199                             NULL);
1200}
1201
1202/* First part is kernel version, which we ignore if module has crcs. */
1203static inline int same_magic(const char *amagic, const char *bmagic,
1204                             bool has_crcs)
1205{
1206        if (has_crcs) {
1207                amagic += strcspn(amagic, " ");
1208                bmagic += strcspn(bmagic, " ");
1209        }
1210        return strcmp(amagic, bmagic) == 0;
1211}
1212#else
1213static inline int check_version(Elf_Shdr *sechdrs,
1214                                unsigned int versindex,
1215                                const char *symname,
1216                                struct module *mod, 
1217                                const unsigned long *crc,
1218                                const struct module *crc_owner)
1219{
1220        return 1;
1221}
1222
1223static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1224                                          unsigned int versindex,
1225                                          struct module *mod)
1226{
1227        return 1;
1228}
1229
1230static inline int same_magic(const char *amagic, const char *bmagic,
1231                             bool has_crcs)
1232{
1233        return strcmp(amagic, bmagic) == 0;
1234}
1235#endif /* CONFIG_MODVERSIONS */
1236
1237/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1238static const struct kernel_symbol *resolve_symbol(struct module *mod,
1239                                                  const struct load_info *info,
1240                                                  const char *name,
1241                                                  char ownername[])
1242{
1243        struct module *owner;
1244        const struct kernel_symbol *sym;
1245        const unsigned long *crc;
1246        int err;
1247
1248        mutex_lock(&module_mutex);
1249        sym = find_symbol(name, &owner, &crc,
1250                          !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1251        if (!sym)
1252                goto unlock;
1253
1254        if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1255                           owner)) {
1256                sym = ERR_PTR(-EINVAL);
1257                goto getname;
1258        }
1259
1260        err = ref_module(mod, owner);
1261        if (err) {
1262                sym = ERR_PTR(err);
1263                goto getname;
1264        }
1265
1266getname:
1267        /* We must make copy under the lock if we failed to get ref. */
1268        strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1269unlock:
1270        mutex_unlock(&module_mutex);
1271        return sym;
1272}
1273
1274static const struct kernel_symbol *
1275resolve_symbol_wait(struct module *mod,
1276                    const struct load_info *info,
1277                    const char *name)
1278{
1279        const struct kernel_symbol *ksym;
1280        char owner[MODULE_NAME_LEN];
1281
1282        if (wait_event_interruptible_timeout(module_wq,
1283                        !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1284                        || PTR_ERR(ksym) != -EBUSY,
1285                                             30 * HZ) <= 0) {
1286                printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1287                       mod->name, owner);
1288        }
1289        return ksym;
1290}
1291
1292/*
1293 * /sys/module/foo/sections stuff
1294 * J. Corbet <corbet@lwn.net>
1295 */
1296#ifdef CONFIG_SYSFS
1297
1298#ifdef CONFIG_KALLSYMS
1299static inline bool sect_empty(const Elf_Shdr *sect)
1300{
1301        return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1302}
1303
1304struct module_sect_attr
1305{
1306        struct module_attribute mattr;
1307        char *name;
1308        unsigned long address;
1309};
1310
1311struct module_sect_attrs
1312{
1313        struct attribute_group grp;
1314        unsigned int nsections;
1315        struct module_sect_attr attrs[0];
1316};
1317
1318static ssize_t module_sect_show(struct module_attribute *mattr,
1319                                struct module_kobject *mk, char *buf)
1320{
1321        struct module_sect_attr *sattr =
1322                container_of(mattr, struct module_sect_attr, mattr);
1323        return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1324}
1325
1326static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1327{
1328        unsigned int section;
1329
1330        for (section = 0; section < sect_attrs->nsections; section++)
1331                kfree(sect_attrs->attrs[section].name);
1332        kfree(sect_attrs);
1333}
1334
1335static void add_sect_attrs(struct module *mod, const struct load_info *info)
1336{
1337        unsigned int nloaded = 0, i, size[2];
1338        struct module_sect_attrs *sect_attrs;
1339        struct module_sect_attr *sattr;
1340        struct attribute **gattr;
1341
1342        /* Count loaded sections and allocate structures */
1343        for (i = 0; i < info->hdr->e_shnum; i++)
1344                if (!sect_empty(&info->sechdrs[i]))
1345                        nloaded++;
1346        size[0] = ALIGN(sizeof(*sect_attrs)
1347                        + nloaded * sizeof(sect_attrs->attrs[0]),
1348                        sizeof(sect_attrs->grp.attrs[0]));
1349        size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1350        sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1351        if (sect_attrs == NULL)
1352                return;
1353
1354        /* Setup section attributes. */
1355        sect_attrs->grp.name = "sections";
1356        sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1357
1358        sect_attrs->nsections = 0;
1359        sattr = &sect_attrs->attrs[0];
1360        gattr = &sect_attrs->grp.attrs[0];
1361        for (i = 0; i < info->hdr->e_shnum; i++) {
1362                Elf_Shdr *sec = &info->sechdrs[i];
1363                if (sect_empty(sec))
1364                        continue;
1365                sattr->address = sec->sh_addr;
1366                sattr->name = kstrdup(info->secstrings + sec->sh_name,
1367                                        GFP_KERNEL);
1368                if (sattr->name == NULL)
1369                        goto out;
1370                sect_attrs->nsections++;
1371                sysfs_attr_init(&sattr->mattr.attr);
1372                sattr->mattr.show = module_sect_show;
1373                sattr->mattr.store = NULL;
1374                sattr->mattr.attr.name = sattr->name;
1375                sattr->mattr.attr.mode = S_IRUGO;
1376                *(gattr++) = &(sattr++)->mattr.attr;
1377        }
1378        *gattr = NULL;
1379
1380        if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1381                goto out;
1382
1383        mod->sect_attrs = sect_attrs;
1384        return;
1385  out:
1386        free_sect_attrs(sect_attrs);
1387}
1388
1389static void remove_sect_attrs(struct module *mod)
1390{
1391        if (mod->sect_attrs) {
1392                sysfs_remove_group(&mod->mkobj.kobj,
1393                                   &mod->sect_attrs->grp);
1394                /* We are positive that no one is using any sect attrs
1395                 * at this point.  Deallocate immediately. */
1396                free_sect_attrs(mod->sect_attrs);
1397                mod->sect_attrs = NULL;
1398        }
1399}
1400
1401/*
1402 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1403 */
1404
1405struct module_notes_attrs {
1406        struct kobject *dir;
1407        unsigned int notes;
1408        struct bin_attribute attrs[0];
1409};
1410
1411static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1412                                 struct bin_attribute *bin_attr,
1413                                 char *buf, loff_t pos, size_t count)
1414{
1415        /*
1416         * The caller checked the pos and count against our size.
1417         */
1418        memcpy(buf, bin_attr->private + pos, count);
1419        return count;
1420}
1421
1422static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1423                             unsigned int i)
1424{
1425        if (notes_attrs->dir) {
1426                while (i-- > 0)
1427                        sysfs_remove_bin_file(notes_attrs->dir,
1428                                              &notes_attrs->attrs[i]);
1429                kobject_put(notes_attrs->dir);
1430        }
1431        kfree(notes_attrs);
1432}
1433
1434static void add_notes_attrs(struct module *mod, const struct load_info *info)
1435{
1436        unsigned int notes, loaded, i;
1437        struct module_notes_attrs *notes_attrs;
1438        struct bin_attribute *nattr;
1439
1440        /* failed to create section attributes, so can't create notes */
1441        if (!mod->sect_attrs)
1442                return;
1443
1444        /* Count notes sections and allocate structures.  */
1445        notes = 0;
1446        for (i = 0; i < info->hdr->e_shnum; i++)
1447                if (!sect_empty(&info->sechdrs[i]) &&
1448                    (info->sechdrs[i].sh_type == SHT_NOTE))
1449                        ++notes;
1450
1451        if (notes == 0)
1452                return;
1453
1454        notes_attrs = kzalloc(sizeof(*notes_attrs)
1455                              + notes * sizeof(notes_attrs->attrs[0]),
1456                              GFP_KERNEL);
1457        if (notes_attrs == NULL)
1458                return;
1459
1460        notes_attrs->notes = notes;
1461        nattr = &notes_attrs->attrs[0];
1462        for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1463                if (sect_empty(&info->sechdrs[i]))
1464                        continue;
1465                if (info->sechdrs[i].sh_type == SHT_NOTE) {
1466                        sysfs_bin_attr_init(nattr);
1467                        nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1468                        nattr->attr.mode = S_IRUGO;
1469                        nattr->size = info->sechdrs[i].sh_size;
1470                        nattr->private = (void *) info->sechdrs[i].sh_addr;
1471                        nattr->read = module_notes_read;
1472                        ++nattr;
1473                }
1474                ++loaded;
1475        }
1476
1477        notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1478        if (!notes_attrs->dir)
1479                goto out;
1480
1481        for (i = 0; i < notes; ++i)
1482                if (sysfs_create_bin_file(notes_attrs->dir,
1483                                          &notes_attrs->attrs[i]))
1484                        goto out;
1485
1486        mod->notes_attrs = notes_attrs;
1487        return;
1488
1489  out:
1490        free_notes_attrs(notes_attrs, i);
1491}
1492
1493static void remove_notes_attrs(struct module *mod)
1494{
1495        if (mod->notes_attrs)
1496                free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1497}
1498
1499#else
1500
1501static inline void add_sect_attrs(struct module *mod,
1502                                  const struct load_info *info)
1503{
1504}
1505
1506static inline void remove_sect_attrs(struct module *mod)
1507{
1508}
1509
1510static inline void add_notes_attrs(struct module *mod,
1511                                   const struct load_info *info)
1512{
1513}
1514
1515static inline void remove_notes_attrs(struct module *mod)
1516{
1517}
1518#endif /* CONFIG_KALLSYMS */
1519
1520static void add_usage_links(struct module *mod)
1521{
1522#ifdef CONFIG_MODULE_UNLOAD
1523        struct module_use *use;
1524        int nowarn;
1525
1526        mutex_lock(&module_mutex);
1527        list_for_each_entry(use, &mod->target_list, target_list) {
1528                nowarn = sysfs_create_link(use->target->holders_dir,
1529                                           &mod->mkobj.kobj, mod->name);
1530        }
1531        mutex_unlock(&module_mutex);
1532#endif
1533}
1534
1535static void del_usage_links(struct module *mod)
1536{
1537#ifdef CONFIG_MODULE_UNLOAD
1538        struct module_use *use;
1539
1540        mutex_lock(&module_mutex);
1541        list_for_each_entry(use, &mod->target_list, target_list)
1542                sysfs_remove_link(use->target->holders_dir, mod->name);
1543        mutex_unlock(&module_mutex);
1544#endif
1545}
1546
1547static int module_add_modinfo_attrs(struct module *mod)
1548{
1549        struct module_attribute *attr;
1550        struct module_attribute *temp_attr;
1551        int error = 0;
1552        int i;
1553
1554        mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1555                                        (ARRAY_SIZE(modinfo_attrs) + 1)),
1556                                        GFP_KERNEL);
1557        if (!mod->modinfo_attrs)
1558                return -ENOMEM;
1559
1560        temp_attr = mod->modinfo_attrs;
1561        for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1562                if (!attr->test ||
1563                    (attr->test && attr->test(mod))) {
1564                        memcpy(temp_attr, attr, sizeof(*temp_attr));
1565                        sysfs_attr_init(&temp_attr->attr);
1566                        error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1567                        ++temp_attr;
1568                }
1569        }
1570        return error;
1571}
1572
1573static void module_remove_modinfo_attrs(struct module *mod)
1574{
1575        struct module_attribute *attr;
1576        int i;
1577
1578        for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1579                /* pick a field to test for end of list */
1580                if (!attr->attr.name)
1581                        break;
1582                sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1583                if (attr->free)
1584                        attr->free(mod);
1585        }
1586        kfree(mod->modinfo_attrs);
1587}
1588
1589static int mod_sysfs_init(struct module *mod)
1590{
1591        int err;
1592        struct kobject *kobj;
1593
1594        if (!module_sysfs_initialized) {
1595                printk(KERN_ERR "%s: module sysfs not initialized\n",
1596                       mod->name);
1597                err = -EINVAL;
1598                goto out;
1599        }
1600
1601        kobj = kset_find_obj(module_kset, mod->name);
1602        if (kobj) {
1603                printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1604                kobject_put(kobj);
1605                err = -EINVAL;
1606                goto out;
1607        }
1608
1609        mod->mkobj.mod = mod;
1610
1611        memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1612        mod->mkobj.kobj.kset = module_kset;
1613        err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1614                                   "%s", mod->name);
1615        if (err)
1616                kobject_put(&mod->mkobj.kobj);
1617
1618        /* delay uevent until full sysfs population */
1619out:
1620        return err;
1621}
1622
1623static int mod_sysfs_setup(struct module *mod,
1624                           const struct load_info *info,
1625                           struct kernel_param *kparam,
1626                           unsigned int num_params)
1627{
1628        int err;
1629
1630        err = mod_sysfs_init(mod);
1631        if (err)
1632                goto out;
1633
1634        mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1635        if (!mod->holders_dir) {
1636                err = -ENOMEM;
1637                goto out_unreg;
1638        }
1639
1640        err = module_param_sysfs_setup(mod, kparam, num_params);
1641        if (err)
1642                goto out_unreg_holders;
1643
1644        err = module_add_modinfo_attrs(mod);
1645        if (err)
1646                goto out_unreg_param;
1647
1648        add_usage_links(mod);
1649        add_sect_attrs(mod, info);
1650        add_notes_attrs(mod, info);
1651
1652        kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1653        return 0;
1654
1655out_unreg_param:
1656        module_param_sysfs_remove(mod);
1657out_unreg_holders:
1658        kobject_put(mod->holders_dir);
1659out_unreg:
1660        kobject_put(&mod->mkobj.kobj);
1661out:
1662        return err;
1663}
1664
1665static void mod_sysfs_fini(struct module *mod)
1666{
1667        remove_notes_attrs(mod);
1668        remove_sect_attrs(mod);
1669        kobject_put(&mod->mkobj.kobj);
1670}
1671
1672#else /* !CONFIG_SYSFS */
1673
1674static int mod_sysfs_setup(struct module *mod,
1675                           const struct load_info *info,
1676                           struct kernel_param *kparam,
1677                           unsigned int num_params)
1678{
1679        return 0;
1680}
1681
1682static void mod_sysfs_fini(struct module *mod)
1683{
1684}
1685
1686static void module_remove_modinfo_attrs(struct module *mod)
1687{
1688}
1689
1690static void del_usage_links(struct module *mod)
1691{
1692}
1693
1694#endif /* CONFIG_SYSFS */
1695
1696static void mod_sysfs_teardown(struct module *mod)
1697{
1698        del_usage_links(mod);
1699        module_remove_modinfo_attrs(mod);
1700        module_param_sysfs_remove(mod);
1701        kobject_put(mod->mkobj.drivers_dir);
1702        kobject_put(mod->holders_dir);
1703        mod_sysfs_fini(mod);
1704}
1705
1706/*
1707 * unlink the module with the whole machine is stopped with interrupts off
1708 * - this defends against kallsyms not taking locks
1709 */
1710static int __unlink_module(void *_mod)
1711{
1712        struct module *mod = _mod;
1713        list_del(&mod->list);
1714        module_bug_cleanup(mod);
1715        return 0;
1716}
1717
1718#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1719/*
1720 * LKM RO/NX protection: protect module's text/ro-data
1721 * from modification and any data from execution.
1722 */
1723void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1724{
1725        unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1726        unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1727
1728        if (end_pfn > begin_pfn)
1729                set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1730}
1731
1732static void set_section_ro_nx(void *base,
1733                        unsigned long text_size,
1734                        unsigned long ro_size,
1735                        unsigned long total_size)
1736{
1737        /* begin and end PFNs of the current subsection */
1738        unsigned long begin_pfn;
1739        unsigned long end_pfn;
1740
1741        /*
1742         * Set RO for module text and RO-data:
1743         * - Always protect first page.
1744         * - Do not protect last partial page.
1745         */
1746        if (ro_size > 0)
1747                set_page_attributes(base, base + ro_size, set_memory_ro);
1748
1749        /*
1750         * Set NX permissions for module data:
1751         * - Do not protect first partial page.
1752         * - Always protect last page.
1753         */
1754        if (total_size > text_size) {
1755                begin_pfn = PFN_UP((unsigned long)base + text_size);
1756                end_pfn = PFN_UP((unsigned long)base + total_size);
1757                if (end_pfn > begin_pfn)
1758                        set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1759        }
1760}
1761
1762static void unset_module_core_ro_nx(struct module *mod)
1763{
1764        set_page_attributes(mod->module_core + mod->core_text_size,
1765                mod->module_core + mod->core_size,
1766                set_memory_x);
1767        set_page_attributes(mod->module_core,
1768                mod->module_core + mod->core_ro_size,
1769                set_memory_rw);
1770}
1771
1772static void unset_module_init_ro_nx(struct module *mod)
1773{
1774        set_page_attributes(mod->module_init + mod->init_text_size,
1775                mod->module_init + mod->init_size,
1776                set_memory_x);
1777        set_page_attributes(mod->module_init,
1778                mod->module_init + mod->init_ro_size,
1779                set_memory_rw);
1780}
1781
1782/* Iterate through all modules and set each module's text as RW */
1783void set_all_modules_text_rw(void)
1784{
1785        struct module *mod;
1786
1787        mutex_lock(&module_mutex);
1788        list_for_each_entry_rcu(mod, &modules, list) {
1789                if ((mod->module_core) && (mod->core_text_size)) {
1790                        set_page_attributes(mod->module_core,
1791                                                mod->module_core + mod->core_text_size,
1792                                                set_memory_rw);
1793                }
1794                if ((mod->module_init) && (mod->init_text_size)) {
1795                        set_page_attributes(mod->module_init,
1796                                                mod->module_init + mod->init_text_size,
1797                                                set_memory_rw);
1798                }
1799        }
1800        mutex_unlock(&module_mutex);
1801}
1802
1803/* Iterate through all modules and set each module's text as RO */
1804void set_all_modules_text_ro(void)
1805{
1806        struct module *mod;
1807
1808        mutex_lock(&module_mutex);
1809        list_for_each_entry_rcu(mod, &modules, list) {
1810                if ((mod->module_core) && (mod->core_text_size)) {
1811                        set_page_attributes(mod->module_core,
1812                                                mod->module_core + mod->core_text_size,
1813                                                set_memory_ro);
1814                }
1815                if ((mod->module_init) && (mod->init_text_size)) {
1816                        set_page_attributes(mod->module_init,
1817                                                mod->module_init + mod->init_text_size,
1818                                                set_memory_ro);
1819                }
1820        }
1821        mutex_unlock(&module_mutex);
1822}
1823#else
1824static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1825static void unset_module_core_ro_nx(struct module *mod) { }
1826static void unset_module_init_ro_nx(struct module *mod) { }
1827#endif
1828
1829void __weak module_free(struct module *mod, void *module_region)
1830{
1831        vfree(module_region);
1832}
1833
1834void __weak module_arch_cleanup(struct module *mod)
1835{
1836}
1837
1838/* Free a module, remove from lists, etc. */
1839static void free_module(struct module *mod)
1840{
1841        trace_module_free(mod);
1842
1843        /* Delete from various lists */
1844        mutex_lock(&module_mutex);
1845        stop_machine(__unlink_module, mod, NULL);
1846        mutex_unlock(&module_mutex);
1847        mod_sysfs_teardown(mod);
1848
1849        /* Remove dynamic debug info */
1850        ddebug_remove_module(mod->name);
1851
1852        /* Arch-specific cleanup. */
1853        module_arch_cleanup(mod);
1854
1855        /* Module unload stuff */
1856        module_unload_free(mod);
1857
1858        /* Free any allocated parameters. */
1859        destroy_params(mod->kp, mod->num_kp);
1860
1861        /* This may be NULL, but that's OK */
1862        unset_module_init_ro_nx(mod);
1863        module_free(mod, mod->module_init);
1864        kfree(mod->args);
1865        percpu_modfree(mod);
1866
1867        /* Free lock-classes: */
1868        lockdep_free_key_range(mod->module_core, mod->core_size);
1869
1870        /* Finally, free the core (containing the module structure) */
1871        unset_module_core_ro_nx(mod);
1872        module_free(mod, mod->module_core);
1873
1874#ifdef CONFIG_MPU
1875        update_protections(current->mm);
1876#endif
1877}
1878
1879void *__symbol_get(const char *symbol)
1880{
1881        struct module *owner;
1882        const struct kernel_symbol *sym;
1883
1884        preempt_disable();
1885        sym = find_symbol(symbol, &owner, NULL, true, true);
1886        if (sym && strong_try_module_get(owner))
1887                sym = NULL;
1888        preempt_enable();
1889
1890        return sym ? (void *)sym->value : NULL;
1891}
1892EXPORT_SYMBOL_GPL(__symbol_get);
1893
1894/*
1895 * Ensure that an exported symbol [global namespace] does not already exist
1896 * in the kernel or in some other module's exported symbol table.
1897 *
1898 * You must hold the module_mutex.
1899 */
1900static int verify_export_symbols(struct module *mod)
1901{
1902        unsigned int i;
1903        struct module *owner;
1904        const struct kernel_symbol *s;
1905        struct {
1906                const struct kernel_symbol *sym;
1907                unsigned int num;
1908        } arr[] = {
1909                { mod->syms, mod->num_syms },
1910                { mod->gpl_syms, mod->num_gpl_syms },
1911                { mod->gpl_future_syms, mod->num_gpl_future_syms },
1912#ifdef CONFIG_UNUSED_SYMBOLS
1913                { mod->unused_syms, mod->num_unused_syms },
1914                { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1915#endif
1916        };
1917
1918        for (i = 0; i < ARRAY_SIZE(arr); i++) {
1919                for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1920                        if (find_symbol(s->name, &owner, NULL, true, false)) {
1921                                printk(KERN_ERR
1922                                       "%s: exports duplicate symbol %s"
1923                                       " (owned by %s)\n",
1924                                       mod->name, s->name, module_name(owner));
1925                                return -ENOEXEC;
1926                        }
1927                }
1928        }
1929        return 0;
1930}
1931
1932/* Change all symbols so that st_value encodes the pointer directly. */
1933static int simplify_symbols(struct module *mod, const struct load_info *info)
1934{
1935        Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1936        Elf_Sym *sym = (void *)symsec->sh_addr;
1937        unsigned long secbase;
1938        unsigned int i;
1939        int ret = 0;
1940        const struct kernel_symbol *ksym;
1941
1942        for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1943                const char *name = info->strtab + sym[i].st_name;
1944
1945                switch (sym[i].st_shndx) {
1946                case SHN_COMMON:
1947                        /* We compiled with -fno-common.  These are not
1948                           supposed to happen.  */
1949                        pr_debug("Common symbol: %s\n", name);
1950                        printk("%s: please compile with -fno-common\n",
1951                               mod->name);
1952                        ret = -ENOEXEC;
1953                        break;
1954
1955                case SHN_ABS:
1956                        /* Don't need to do anything */
1957                        pr_debug("Absolute symbol: 0x%08lx\n",
1958                               (long)sym[i].st_value);
1959                        break;
1960
1961                case SHN_UNDEF:
1962                        ksym = resolve_symbol_wait(mod, info, name);
1963                        /* Ok if resolved.  */
1964                        if (ksym && !IS_ERR(ksym)) {
1965                                sym[i].st_value = ksym->value;
1966                                break;
1967                        }
1968
1969                        /* Ok if weak.  */
1970                        if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1971                                break;
1972
1973                        printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1974                               mod->name, name, PTR_ERR(ksym));
1975                        ret = PTR_ERR(ksym) ?: -ENOENT;
1976                        break;
1977
1978                default:
1979                        /* Divert to percpu allocation if a percpu var. */
1980                        if (sym[i].st_shndx == info->index.pcpu)
1981                                secbase = (unsigned long)mod_percpu(mod);
1982                        else
1983                                secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1984                        sym[i].st_value += secbase;
1985                        break;
1986                }
1987        }
1988
1989        return ret;
1990}
1991
1992static int apply_relocations(struct module *mod, const struct load_info *info)
1993{
1994        unsigned int i;
1995        int err = 0;
1996
1997        /* Now do relocations. */
1998        for (i = 1; i < info->hdr->e_shnum; i++) {
1999                unsigned int infosec = info->sechdrs[i].sh_info;
2000
2001                /* Not a valid relocation section? */
2002                if (infosec >= info->hdr->e_shnum)
2003                        continue;
2004
2005                /* Don't bother with non-allocated sections */
2006                if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2007                        continue;
2008
2009                if (info->sechdrs[i].sh_type == SHT_REL)
2010                        err = apply_relocate(info->sechdrs, info->strtab,
2011                                             info->index.sym, i, mod);
2012                else if (info->sechdrs[i].sh_type == SHT_RELA)
2013                        err = apply_relocate_add(info->sechdrs, info->strtab,
2014                                                 info->index.sym, i, mod);
2015                if (err < 0)
2016                        break;
2017        }
2018        return err;
2019}
2020
2021/* Additional bytes needed by arch in front of individual sections */
2022unsigned int __weak arch_mod_section_prepend(struct module *mod,
2023                                             unsigned int section)
2024{
2025        /* default implementation just returns zero */
2026        return 0;
2027}
2028
2029/* Update size with this section: return offset. */
2030static long get_offset(struct module *mod, unsigned int *size,
2031                       Elf_Shdr *sechdr, unsigned int section)
2032{
2033        long ret;
2034
2035        *size += arch_mod_section_prepend(mod, section);
2036        ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2037        *size = ret + sechdr->sh_size;
2038        return ret;
2039}
2040
2041/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2042   might -- code, read-only data, read-write data, small data.  Tally
2043   sizes, and place the offsets into sh_entsize fields: high bit means it
2044   belongs in init. */
2045static void layout_sections(struct module *mod, struct load_info *info)
2046{
2047        static unsigned long const masks[][2] = {
2048                /* NOTE: all executable code must be the first section
2049                 * in this array; otherwise modify the text_size
2050                 * finder in the two loops below */
2051                { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2052                { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2053                { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2054                { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2055        };
2056        unsigned int m, i;
2057
2058        for (i = 0; i < info->hdr->e_shnum; i++)
2059                info->sechdrs[i].sh_entsize = ~0UL;
2060
2061        pr_debug("Core section allocation order:\n");
2062        for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2063                for (i = 0; i < info->hdr->e_shnum; ++i) {
2064                        Elf_Shdr *s = &info->sechdrs[i];
2065                        const char *sname = info->secstrings + s->sh_name;
2066
2067                        if ((s->sh_flags & masks[m][0]) != masks[m][0]
2068                            || (s->sh_flags & masks[m][1])
2069                            || s->sh_entsize != ~0UL
2070                            || strstarts(sname, ".init"))
2071                                continue;
2072                        s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2073                        pr_debug("\t%s\n", sname);
2074                }
2075                switch (m) {
2076                case 0: /* executable */
2077                        mod->core_size = debug_align(mod->core_size);
2078                        mod->core_text_size = mod->core_size;
2079                        break;
2080                case 1: /* RO: text and ro-data */
2081                        mod->core_size = debug_align(mod->core_size);
2082                        mod->core_ro_size = mod->core_size;
2083                        break;
2084                case 3: /* whole core */
2085                        mod->core_size = debug_align(mod->core_size);
2086                        break;
2087                }
2088        }
2089
2090        pr_debug("Init section allocation order:\n");
2091        for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2092                for (i = 0; i < info->hdr->e_shnum; ++i) {
2093                        Elf_Shdr *s = &info->sechdrs[i];
2094                        const char *sname = info->secstrings + s->sh_name;
2095
2096                        if ((s->sh_flags & masks[m][0]) != masks[m][0]
2097                            || (s->sh_flags & masks[m][1])
2098                            || s->sh_entsize != ~0UL
2099                            || !strstarts(sname, ".init"))
2100                                continue;
2101                        s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2102                                         | INIT_OFFSET_MASK);
2103                        pr_debug("\t%s\n", sname);
2104                }
2105                switch (m) {
2106                case 0: /* executable */
2107                        mod->init_size = debug_align(mod->init_size);
2108                        mod->init_text_size = mod->init_size;
2109                        break;
2110                case 1: /* RO: text and ro-data */
2111                        mod->init_size = debug_align(mod->init_size);
2112                        mod->init_ro_size = mod->init_size;
2113                        break;
2114                case 3: /* whole init */
2115                        mod->init_size = debug_align(mod->init_size);
2116                        break;
2117                }
2118        }
2119}
2120
2121static void set_license(struct module *mod, const char *license)
2122{
2123        if (!license)
2124                license = "unspecified";
2125
2126        if (!license_is_gpl_compatible(license)) {
2127                if (!test_taint(TAINT_PROPRIETARY_MODULE))
2128                        printk(KERN_WARNING "%s: module license '%s' taints "
2129                                "kernel.\n", mod->name, license);
2130                add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2131        }
2132}
2133
2134/* Parse tag=value strings from .modinfo section */
2135static char *next_string(char *string, unsigned long *secsize)
2136{
2137        /* Skip non-zero chars */
2138        while (string[0]) {
2139                string++;
2140                if ((*secsize)-- <= 1)
2141                        return NULL;
2142        }
2143
2144        /* Skip any zero padding. */
2145        while (!string[0]) {
2146                string++;
2147                if ((*secsize)-- <= 1)
2148                        return NULL;
2149        }
2150        return string;
2151}
2152
2153static char *get_modinfo(struct load_info *info, const char *tag)
2154{
2155        char *p;
2156        unsigned int taglen = strlen(tag);
2157        Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2158        unsigned long size = infosec->sh_size;
2159
2160        for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2161                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2162                        return p + taglen + 1;
2163        }
2164        return NULL;
2165}
2166
2167static void setup_modinfo(struct module *mod, struct load_info *info)
2168{
2169        struct module_attribute *attr;
2170        int i;
2171
2172        for (i = 0; (attr = modinfo_attrs[i]); i++) {
2173                if (attr->setup)
2174                        attr->setup(mod, get_modinfo(info, attr->attr.name));
2175        }
2176}
2177
2178static void free_modinfo(struct module *mod)
2179{
2180        struct module_attribute *attr;
2181        int i;
2182
2183        for (i = 0; (attr = modinfo_attrs[i]); i++) {
2184                if (attr->free)
2185                        attr->free(mod);
2186        }
2187}
2188
2189#ifdef CONFIG_KALLSYMS
2190
2191/* lookup symbol in given range of kernel_symbols */
2192static const struct kernel_symbol *lookup_symbol(const char *name,
2193        const struct kernel_symbol *start,
2194        const struct kernel_symbol *stop)
2195{
2196        return bsearch(name, start, stop - start,
2197                        sizeof(struct kernel_symbol), cmp_name);
2198}
2199
2200static int is_exported(const char *name, unsigned long value,
2201                       const struct module *mod)
2202{
2203        const struct kernel_symbol *ks;
2204        if (!mod)
2205                ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2206        else
2207                ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2208        return ks != NULL && ks->value == value;
2209}
2210
2211/* As per nm */
2212static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2213{
2214        const Elf_Shdr *sechdrs = info->sechdrs;
2215
2216        if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2217                if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2218                        return 'v';
2219                else
2220                        return 'w';
2221        }
2222        if (sym->st_shndx == SHN_UNDEF)
2223                return 'U';
2224        if (sym->st_shndx == SHN_ABS)
2225                return 'a';
2226        if (sym->st_shndx >= SHN_LORESERVE)
2227                return '?';
2228        if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2229                return 't';
2230        if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2231            && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2232                if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2233                        return 'r';
2234                else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2235                        return 'g';
2236                else
2237                        return 'd';
2238        }
2239        if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2240                if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2241                        return 's';
2242                else
2243                        return 'b';
2244        }
2245        if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2246                      ".debug")) {
2247                return 'n';
2248        }
2249        return '?';
2250}
2251
2252static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2253                           unsigned int shnum)
2254{
2255        const Elf_Shdr *sec;
2256
2257        if (src->st_shndx == SHN_UNDEF
2258            || src->st_shndx >= shnum
2259            || !src->st_name)
2260                return false;
2261
2262        sec = sechdrs + src->st_shndx;
2263        if (!(sec->sh_flags & SHF_ALLOC)
2264#ifndef CONFIG_KALLSYMS_ALL
2265            || !(sec->sh_flags & SHF_EXECINSTR)
2266#endif
2267            || (sec->sh_entsize & INIT_OFFSET_MASK))
2268                return false;
2269
2270        return true;
2271}
2272
2273/*
2274 * We only allocate and copy the strings needed by the parts of symtab
2275 * we keep.  This is simple, but has the effect of making multiple
2276 * copies of duplicates.  We could be more sophisticated, see
2277 * linux-kernel thread starting with
2278 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2279 */
2280static void layout_symtab(struct module *mod, struct load_info *info)
2281{
2282        Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2283        Elf_Shdr *strsect = info->sechdrs + info->index.str;
2284        const Elf_Sym *src;
2285        unsigned int i, nsrc, ndst, strtab_size;
2286
2287        /* Put symbol section at end of init part of module. */
2288        symsect->sh_flags |= SHF_ALLOC;
2289        symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2290                                         info->index.sym) | INIT_OFFSET_MASK;
2291        pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2292
2293        src = (void *)info->hdr + symsect->sh_offset;
2294        nsrc = symsect->sh_size / sizeof(*src);
2295
2296        /* strtab always starts with a nul, so offset 0 is the empty string. */
2297        strtab_size = 1;
2298
2299        /* Compute total space required for the core symbols' strtab. */
2300        for (ndst = i = 0; i < nsrc; i++) {
2301                if (i == 0 ||
2302                    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2303                        strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2304                        ndst++;
2305                }
2306        }
2307
2308        /* Append room for core symbols at end of core part. */
2309        info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2310        info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2311        mod->core_size += strtab_size;
2312
2313        /* Put string table section at end of init part of module. */
2314        strsect->sh_flags |= SHF_ALLOC;
2315        strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2316                                         info->index.str) | INIT_OFFSET_MASK;
2317        pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2318}
2319
2320static void add_kallsyms(struct module *mod, const struct load_info *info)
2321{
2322        unsigned int i, ndst;
2323        const Elf_Sym *src;
2324        Elf_Sym *dst;
2325        char *s;
2326        Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2327
2328        mod->symtab = (void *)symsec->sh_addr;
2329        mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2330        /* Make sure we get permanent strtab: don't use info->strtab. */
2331        mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2332
2333        /* Set types up while we still have access to sections. */
2334        for (i = 0; i < mod->num_symtab; i++)
2335                mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2336
2337        mod->core_symtab = dst = mod->module_core + info->symoffs;
2338        mod->core_strtab = s = mod->module_core + info->stroffs;
2339        src = mod->symtab;
2340        *s++ = 0;
2341        for (ndst = i = 0; i < mod->num_symtab; i++) {
2342                if (i == 0 ||
2343                    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2344                        dst[ndst] = src[i];
2345                        dst[ndst++].st_name = s - mod->core_strtab;
2346                        s += strlcpy(s, &mod->strtab[src[i].st_name],
2347                                     KSYM_NAME_LEN) + 1;
2348                }
2349        }
2350        mod->core_num_syms = ndst;
2351}
2352#else
2353static inline void layout_symtab(struct module *mod, struct load_info *info)
2354{
2355}
2356
2357static void add_kallsyms(struct module *mod, const struct load_info *info)
2358{
2359}
2360#endif /* CONFIG_KALLSYMS */
2361
2362static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2363{
2364        if (!debug)
2365                return;
2366#ifdef CONFIG_DYNAMIC_DEBUG
2367        if (ddebug_add_module(debug, num, debug->modname))
2368                printk(KERN_ERR "dynamic debug error adding module: %s\n",
2369                                        debug->modname);
2370#endif
2371}
2372
2373static void dynamic_debug_remove(struct _ddebug *debug)
2374{
2375        if (debug)
2376                ddebug_remove_module(debug->modname);
2377}
2378
2379void * __weak module_alloc(unsigned long size)
2380{
2381        return size == 0 ? NULL : vmalloc_exec(size);
2382}
2383
2384static void *module_alloc_update_bounds(unsigned long size)
2385{
2386        void *ret = module_alloc(size);
2387
2388        if (ret) {
2389                mutex_lock(&module_mutex);
2390                /* Update module bounds. */
2391                if ((unsigned long)ret < module_addr_min)
2392                        module_addr_min = (unsigned long)ret;
2393                if ((unsigned long)ret + size > module_addr_max)
2394                        module_addr_max = (unsigned long)ret + size;
2395                mutex_unlock(&module_mutex);
2396        }
2397        return ret;
2398}
2399
2400#ifdef CONFIG_DEBUG_KMEMLEAK
2401static void kmemleak_load_module(const struct module *mod,
2402                                 const struct load_info *info)
2403{
2404        unsigned int i;
2405
2406        /* only scan the sections containing data */
2407        kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2408
2409        for (i = 1; i < info->hdr->e_shnum; i++) {
2410                const char *name = info->secstrings + info->sechdrs[i].sh_name;
2411                if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2412                        continue;
2413                if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2414                        continue;
2415
2416                kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2417                                   info->sechdrs[i].sh_size, GFP_KERNEL);
2418        }
2419}
2420#else
2421static inline void kmemleak_load_module(const struct module *mod,
2422                                        const struct load_info *info)
2423{
2424}
2425#endif
2426
2427#ifdef CONFIG_MODULE_SIG
2428static int module_sig_check(struct load_info *info,
2429                            const void *mod, unsigned long *_len)
2430{
2431        int err = -ENOKEY;
2432        unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2433        unsigned long len = *_len;
2434
2435        if (len > markerlen &&
2436            memcmp(mod + len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2437                /* We truncate the module to discard the signature */
2438                *_len -= markerlen;
2439                err = mod_verify_sig(mod, _len);
2440        }
2441
2442        if (!err) {
2443                info->sig_ok = true;
2444                return 0;
2445        }
2446
2447        /* Not having a signature is only an error if we're strict. */
2448        if (err < 0 && fips_enabled)
2449                panic("Module verification failed with error %d in FIPS mode\n",
2450                      err);
2451        if (err == -ENOKEY && !sig_enforce)
2452                err = 0;
2453
2454        return err;
2455}
2456#else /* !CONFIG_MODULE_SIG */
2457static int module_sig_check(struct load_info *info,
2458                            void *mod, unsigned long *len)
2459{
2460        return 0;
2461}
2462#endif /* !CONFIG_MODULE_SIG */
2463
2464/* Sets info->hdr, info->len and info->sig_ok. */
2465static int copy_and_check(struct load_info *info,
2466                          const void __user *umod, unsigned long len,
2467                          const char __user *uargs)
2468{
2469        int err;
2470        Elf_Ehdr *hdr;
2471
2472        if (len < sizeof(*hdr))
2473                return -ENOEXEC;
2474
2475        /* Suck in entire file: we'll want most of it. */
2476        if ((hdr = vmalloc(len)) == NULL)
2477                return -ENOMEM;
2478
2479        if (copy_from_user(hdr, umod, len) != 0) {
2480                err = -EFAULT;
2481                goto free_hdr;
2482        }
2483
2484        err = module_sig_check(info, hdr, &len);
2485        if (err)
2486                goto free_hdr;
2487
2488        /* Sanity checks against insmoding binaries or wrong arch,
2489           weird elf version */
2490        if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2491            || hdr->e_type != ET_REL
2492            || !elf_check_arch(hdr)
2493            || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2494                err = -ENOEXEC;
2495                goto free_hdr;
2496        }
2497
2498        if (hdr->e_shoff >= len ||
2499            hdr->e_shnum * sizeof(Elf_Shdr) > len - hdr->e_shoff) {
2500                err = -ENOEXEC;
2501                goto free_hdr;
2502        }
2503
2504        info->hdr = hdr;
2505        info->len = len;
2506        return 0;
2507
2508free_hdr:
2509        vfree(hdr);
2510        return err;
2511}
2512
2513static void free_copy(struct load_info *info)
2514{
2515        vfree(info->hdr);
2516}
2517
2518static int rewrite_section_headers(struct load_info *info)
2519{
2520        unsigned int i;
2521
2522        /* This should always be true, but let's be sure. */
2523        info->sechdrs[0].sh_addr = 0;
2524
2525        for (i = 1; i < info->hdr->e_shnum; i++) {
2526                Elf_Shdr *shdr = &info->sechdrs[i];
2527                if (shdr->sh_type != SHT_NOBITS
2528                    && info->len < shdr->sh_offset + shdr->sh_size) {
2529                        printk(KERN_ERR "Module len %lu truncated\n",
2530                               info->len);
2531                        return -ENOEXEC;
2532                }
2533
2534                /* Mark all sections sh_addr with their address in the
2535                   temporary image. */
2536                shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2537
2538#ifndef CONFIG_MODULE_UNLOAD
2539                /* Don't load .exit sections */
2540                if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2541                        shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2542#endif
2543        }
2544
2545        /* Track but don't keep modinfo and version sections. */
2546        info->index.vers = find_sec(info, "__versions");
2547        info->index.info = find_sec(info, ".modinfo");
2548        info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2549        info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2550        return 0;
2551}
2552
2553/*
2554 * Set up our basic convenience variables (pointers to section headers,
2555 * search for module section index etc), and do some basic section
2556 * verification.
2557 *
2558 * Return the temporary module pointer (we'll replace it with the final
2559 * one when we move the module sections around).
2560 */
2561static struct module *setup_load_info(struct load_info *info)
2562{
2563        unsigned int i;
2564        int err;
2565        struct module *mod;
2566
2567        /* Set up the convenience variables */
2568        info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2569        info->secstrings = (void *)info->hdr
2570                + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2571
2572        err = rewrite_section_headers(info);
2573        if (err)
2574                return ERR_PTR(err);
2575
2576        /* Find internal symbols and strings. */
2577        for (i = 1; i < info->hdr->e_shnum; i++) {
2578                if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2579                        info->index.sym = i;
2580                        info->index.str = info->sechdrs[i].sh_link;
2581                        info->strtab = (char *)info->hdr
2582                                + info->sechdrs[info->index.str].sh_offset;
2583                        break;
2584                }
2585        }
2586
2587        info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2588        if (!info->index.mod) {
2589                printk(KERN_WARNING "No module found in object\n");
2590                return ERR_PTR(-ENOEXEC);
2591        }
2592        /* This is temporary: point mod into copy of data. */
2593        mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2594
2595        if (info->index.sym == 0) {
2596                printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2597                       mod->name);
2598                return ERR_PTR(-ENOEXEC);
2599        }
2600
2601        info->index.pcpu = find_pcpusec(info);
2602
2603        /* Check module struct version now, before we try to use module. */
2604        if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2605                return ERR_PTR(-ENOEXEC);
2606
2607        return mod;
2608}
2609
2610static int check_modinfo(struct module *mod, struct load_info *info)
2611{
2612        const char *modmagic = get_modinfo(info, "vermagic");
2613        int err;
2614
2615        /* This is allowed: modprobe --force will invalidate it. */
2616        if (!modmagic) {
2617                err = try_to_force_load(mod, "bad vermagic");
2618                if (err)
2619                        return err;
2620        } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2621                printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2622                       mod->name, modmagic, vermagic);
2623                return -ENOEXEC;
2624        }
2625
2626        if (!get_modinfo(info, "intree"))
2627                add_taint_module(mod, TAINT_OOT_MODULE);
2628
2629        if (get_modinfo(info, "staging")) {
2630                add_taint_module(mod, TAINT_CRAP);
2631                printk(KERN_WARNING "%s: module is from the staging directory,"
2632                       " the quality is unknown, you have been warned.\n",
2633                       mod->name);
2634        }
2635
2636        /* Set up license info based on the info section */
2637        set_license(mod, get_modinfo(info, "license"));
2638
2639        return 0;
2640}
2641
2642static void find_module_sections(struct module *mod, struct load_info *info)
2643{
2644        mod->kp = section_objs(info, "__param",
2645                               sizeof(*mod->kp), &mod->num_kp);
2646        mod->syms = section_objs(info, "__ksymtab",
2647                                 sizeof(*mod->syms), &mod->num_syms);
2648        mod->crcs = section_addr(info, "__kcrctab");
2649        mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2650                                     sizeof(*mod->gpl_syms),
2651                                     &mod->num_gpl_syms);
2652        mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2653        mod->gpl_future_syms = section_objs(info,
2654                                            "__ksymtab_gpl_future",
2655                                            sizeof(*mod->gpl_future_syms),
2656                                            &mod->num_gpl_future_syms);
2657        mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2658
2659#ifdef CONFIG_UNUSED_SYMBOLS
2660        mod->unused_syms = section_objs(info, "__ksymtab_unused",
2661                                        sizeof(*mod->unused_syms),
2662                                        &mod->num_unused_syms);
2663        mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2664        mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2665                                            sizeof(*mod->unused_gpl_syms),
2666                                            &mod->num_unused_gpl_syms);
2667        mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2668#endif
2669#ifdef CONFIG_CONSTRUCTORS
2670        mod->ctors = section_objs(info, ".ctors",
2671                                  sizeof(*mod->ctors), &mod->num_ctors);
2672#endif
2673
2674#ifdef CONFIG_TRACEPOINTS
2675        mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2676                                             sizeof(*mod->tracepoints_ptrs),
2677                                             &mod->num_tracepoints);
2678#endif
2679#ifdef HAVE_JUMP_LABEL
2680        mod->jump_entries = section_objs(info, "__jump_table",
2681                                        sizeof(*mod->jump_entries),
2682                                        &mod->num_jump_entries);
2683#endif
2684#ifdef CONFIG_EVENT_TRACING
2685        mod->trace_events = section_objs(info, "_ftrace_events",
2686                                         sizeof(*mod->trace_events),
2687                                         &mod->num_trace_events);
2688        /*
2689         * This section contains pointers to allocated objects in the trace
2690         * code and not scanning it leads to false positives.
2691         */
2692        kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2693                           mod->num_trace_events, GFP_KERNEL);
2694#endif
2695#ifdef CONFIG_TRACING
2696        mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2697                                         sizeof(*mod->trace_bprintk_fmt_start),
2698                                         &mod->num_trace_bprintk_fmt);
2699        /*
2700         * This section contains pointers to allocated objects in the trace
2701         * code and not scanning it leads to false positives.
2702         */
2703        kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2704                           sizeof(*mod->trace_bprintk_fmt_start) *
2705                           mod->num_trace_bprintk_fmt, GFP_KERNEL);
2706#endif
2707#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2708        /* sechdrs[0].sh_size is always zero */
2709        mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2710                                             sizeof(*mod->ftrace_callsites),
2711                                             &mod->num_ftrace_callsites);
2712#endif
2713
2714        mod->extable = section_objs(info, "__ex_table",
2715                                    sizeof(*mod->extable), &mod->num_exentries);
2716
2717        if (section_addr(info, "__obsparm"))
2718                printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2719                       mod->name);
2720
2721        info->debug = section_objs(info, "__verbose",
2722                                   sizeof(*info->debug), &info->num_debug);
2723}
2724
2725static int move_module(struct module *mod, struct load_info *info)
2726{
2727        int i;
2728        void *ptr;
2729
2730        /* Do the allocs. */
2731        ptr = module_alloc_update_bounds(mod->core_size);
2732        /*
2733         * The pointer to this block is stored in the module structure
2734         * which is inside the block. Just mark it as not being a
2735         * leak.
2736         */
2737        kmemleak_not_leak(ptr);
2738        if (!ptr)
2739                return -ENOMEM;
2740
2741        memset(ptr, 0, mod->core_size);
2742        mod->module_core = ptr;
2743
2744        ptr = module_alloc_update_bounds(mod->init_size);
2745        /*
2746         * The pointer to this block is stored in the module structure
2747         * which is inside the block. This block doesn't need to be
2748         * scanned as it contains data and code that will be freed
2749         * after the module is initialized.
2750         */
2751        kmemleak_ignore(ptr);
2752        if (!ptr && mod->init_size) {
2753                module_free(mod, mod->module_core);
2754                return -ENOMEM;
2755        }
2756        memset(ptr, 0, mod->init_size);
2757        mod->module_init = ptr;
2758
2759        /* Transfer each section which specifies SHF_ALLOC */
2760        pr_debug("final section addresses:\n");
2761        for (i = 0; i < info->hdr->e_shnum; i++) {
2762                void *dest;
2763                Elf_Shdr *shdr = &info->sechdrs[i];
2764
2765                if (!(shdr->sh_flags & SHF_ALLOC))
2766                        continue;
2767
2768                if (shdr->sh_entsize & INIT_OFFSET_MASK)
2769                        dest = mod->module_init
2770                                + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2771                else
2772                        dest = mod->module_core + shdr->sh_entsize;
2773
2774                if (shdr->sh_type != SHT_NOBITS)
2775                        memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2776                /* Update sh_addr to point to copy in image. */
2777                shdr->sh_addr = (unsigned long)dest;
2778                pr_debug("\t0x%lx %s\n",
2779                         (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2780        }
2781
2782        return 0;
2783}
2784
2785static int check_module_license_and_versions(struct module *mod)
2786{
2787        /*
2788         * ndiswrapper is under GPL by itself, but loads proprietary modules.
2789         * Don't use add_taint_module(), as it would prevent ndiswrapper from
2790         * using GPL-only symbols it needs.
2791         */
2792        if (strcmp(mod->name, "ndiswrapper") == 0)
2793                add_taint(TAINT_PROPRIETARY_MODULE);
2794
2795        /* driverloader was caught wrongly pretending to be under GPL */
2796        if (strcmp(mod->name, "driverloader") == 0)
2797                add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2798
2799        /* lve claims to be GPL but upstream won't provide source */
2800        if (strcmp(mod->name, "lve") == 0)
2801                add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2802
2803#ifdef CONFIG_MODVERSIONS
2804        if ((mod->num_syms && !mod->crcs)
2805            || (mod->num_gpl_syms && !mod->gpl_crcs)
2806            || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2807#ifdef CONFIG_UNUSED_SYMBOLS
2808            || (mod->num_unused_syms && !mod->unused_crcs)
2809            || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2810#endif
2811                ) {
2812                return try_to_force_load(mod,
2813                                         "no versions for exported symbols");
2814        }
2815#endif
2816        return 0;
2817}
2818
2819static void flush_module_icache(const struct module *mod)
2820{
2821        mm_segment_t old_fs;
2822
2823        /* flush the icache in correct context */
2824        old_fs = get_fs();
2825        set_fs(KERNEL_DS);
2826
2827        /*
2828         * Flush the instruction cache, since we've played with text.
2829         * Do it before processing of module parameters, so the module
2830         * can provide parameter accessor functions of its own.
2831         */
2832        if (mod->module_init)
2833                flush_icache_range((unsigned long)mod->module_init,
2834                                   (unsigned long)mod->module_init
2835                                   + mod->init_size);
2836        flush_icache_range((unsigned long)mod->module_core,
2837                           (unsigned long)mod->module_core + mod->core_size);
2838
2839        set_fs(old_fs);
2840}
2841
2842int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2843                                     Elf_Shdr *sechdrs,
2844                                     char *secstrings,
2845                                     struct module *mod)
2846{
2847        return 0;
2848}
2849
2850static struct module *layout_and_allocate(struct load_info *info)
2851{
2852        /* Module within temporary copy. */
2853        struct module *mod;
2854        Elf_Shdr *pcpusec;
2855        int err;
2856
2857        mod = setup_load_info(info);
2858        if (IS_ERR(mod))
2859                return mod;
2860
2861        err = check_modinfo(mod, info);
2862        if (err)
2863                return ERR_PTR(err);
2864
2865        /* Allow arches to frob section contents and sizes.  */
2866        err = module_frob_arch_sections(info->hdr, info->sechdrs,
2867                                        info->secstrings, mod);
2868        if (err < 0)
2869                goto out;
2870
2871        pcpusec = &info->sechdrs[info->index.pcpu];
2872        if (pcpusec->sh_size) {
2873                /* We have a special allocation for this section. */
2874                err = percpu_modalloc(mod,
2875                                      pcpusec->sh_size, pcpusec->sh_addralign);
2876                if (err)
2877                        goto out;
2878                pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2879        }
2880
2881        /* Determine total sizes, and put offsets in sh_entsize.  For now
2882           this is done generically; there doesn't appear to be any
2883           special cases for the architectures. */
2884        layout_sections(mod, info);
2885        layout_symtab(mod, info);
2886
2887        /* Allocate and move to the final place */
2888        err = move_module(mod, info);
2889        if (err)
2890                goto free_percpu;
2891
2892        /* Module has been copied to its final place now: return it. */
2893        mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2894        kmemleak_load_module(mod, info);
2895        return mod;
2896
2897free_percpu:
2898        percpu_modfree(mod);
2899out:
2900        return ERR_PTR(err);
2901}
2902
2903/* mod is no longer valid after this! */
2904static void module_deallocate(struct module *mod, struct load_info *info)
2905{
2906        percpu_modfree(mod);
2907        module_free(mod, mod->module_init);
2908        module_free(mod, mod->module_core);
2909}
2910
2911int __weak module_finalize(const Elf_Ehdr *hdr,
2912                           const Elf_Shdr *sechdrs,
2913                           struct module *me)
2914{
2915        return 0;
2916}
2917
2918static int post_relocation(struct module *mod, const struct load_info *info)
2919{
2920        /* Sort exception table now relocations are done. */
2921        sort_extable(mod->extable, mod->extable + mod->num_exentries);
2922
2923        /* Copy relocated percpu area over. */
2924        percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2925                       info->sechdrs[info->index.pcpu].sh_size);
2926
2927        /* Setup kallsyms-specific fields. */
2928        add_kallsyms(mod, info);
2929
2930        /* Arch-specific module finalizing. */
2931        return module_finalize(info->hdr, info->sechdrs, mod);
2932}
2933
2934/* Is this module of this name done loading?  No locks held. */
2935static bool finished_loading(const char *name)
2936{
2937        struct module *mod;
2938        bool ret;
2939
2940        mutex_lock(&module_mutex);
2941        mod = find_module(name);
2942        ret = !mod || mod->state != MODULE_STATE_COMING;
2943        mutex_unlock(&module_mutex);
2944
2945        return ret;
2946}
2947
2948/* Allocate and load the module: note that size of section 0 is always
2949   zero, and we rely on this for optional sections. */
2950static struct module *load_module(void __user *umod,
2951                                  unsigned long len,
2952                                  const char __user *uargs)
2953{
2954        struct load_info info = { NULL, };
2955        struct module *mod, *old;
2956        long err;
2957
2958        pr_debug("load_module: umod=%p, len=%lu, uargs=%p\n",
2959               umod, len, uargs);
2960
2961        /* Copy in the blobs from userspace, check they are vaguely sane. */
2962        err = copy_and_check(&info, umod, len, uargs);
2963        if (err)
2964                return ERR_PTR(err);
2965
2966        /* Figure out module layout, and allocate all the memory. */
2967        mod = layout_and_allocate(&info);
2968        if (IS_ERR(mod)) {
2969                err = PTR_ERR(mod);
2970                goto free_copy;
2971        }
2972
2973#ifdef CONFIG_MODULE_SIG
2974        mod->sig_ok = info.sig_ok;
2975        if (!mod->sig_ok)
2976                add_taint_module(mod, TAINT_FORCED_MODULE);
2977#endif
2978
2979        /* Now module is in final location, initialize linked lists, etc. */
2980        err = module_unload_init(mod);
2981        if (err)
2982                goto free_module;
2983
2984        /* Now we've got everything in the final locations, we can
2985         * find optional sections. */
2986        find_module_sections(mod, &info);
2987
2988        err = check_module_license_and_versions(mod);
2989        if (err)
2990                goto free_unload;
2991
2992        /* Set up MODINFO_ATTR fields */
2993        setup_modinfo(mod, &info);
2994
2995        /* Fix up syms, so that st_value is a pointer to location. */
2996        err = simplify_symbols(mod, &info);
2997        if (err < 0)
2998                goto free_modinfo;
2999
3000        err = apply_relocations(mod, &info);
3001        if (err < 0)
3002                goto free_modinfo;
3003
3004        err = post_relocation(mod, &info);
3005        if (err < 0)
3006                goto free_modinfo;
3007
3008        flush_module_icache(mod);
3009
3010        /* Now copy in args */
3011        mod->args = strndup_user(uargs, ~0UL >> 1);
3012        if (IS_ERR(mod->args)) {
3013                err = PTR_ERR(mod->args);
3014                goto free_arch_cleanup;
3015        }
3016
3017        /* Mark state as coming so strong_try_module_get() ignores us. */
3018        mod->state = MODULE_STATE_COMING;
3019
3020        /* Now sew it into the lists so we can get lockdep and oops
3021         * info during argument parsing.  No one should access us, since
3022         * strong_try_module_get() will fail.
3023         * lockdep/oops can run asynchronous, so use the RCU list insertion
3024         * function to insert in a way safe to concurrent readers.
3025         * The mutex protects against concurrent writers.
3026         */
3027again:
3028        mutex_lock(&module_mutex);
3029        if ((old = find_module(mod->name)) != NULL) {
3030                if (old->state == MODULE_STATE_COMING) {
3031                        /* Wait in case it fails to load. */
3032                        mutex_unlock(&module_mutex);
3033                        err = wait_event_interruptible(module_wq,
3034                                               finished_loading(mod->name));
3035                        if (err)
3036                                goto free_arch_cleanup;
3037                        goto again;
3038                }
3039                err = -EEXIST;
3040                goto unlock;
3041        }
3042
3043        /* This has to be done once we're sure module name is unique. */
3044        dynamic_debug_setup(info.debug, info.num_debug);
3045
3046        /* Find duplicate symbols */
3047        err = verify_export_symbols(mod);
3048        if (err < 0)
3049                goto ddebug;
3050
3051        module_bug_finalize(info.hdr, info.sechdrs, mod);
3052        list_add_rcu(&mod->list, &modules);
3053        mutex_unlock(&module_mutex);
3054
3055        /* Module is ready to execute: parsing args may do that. */
3056        err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3057                         -32768, 32767, &ddebug_dyndbg_module_param_cb);
3058        if (err < 0)
3059                goto unlink;
3060
3061        /* Link in to syfs. */
3062        err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
3063        if (err < 0)
3064                goto unlink;
3065
3066        /* Get rid of temporary copy. */
3067        free_copy(&info);
3068
3069        /* Done! */
3070        trace_module_load(mod);
3071        return mod;
3072
3073 unlink:
3074        mutex_lock(&module_mutex);
3075        /* Unlink carefully: kallsyms could be walking list. */
3076        list_del_rcu(&mod->list);
3077        module_bug_cleanup(mod);
3078        wake_up_all(&module_wq);
3079 ddebug:
3080        dynamic_debug_remove(info.debug);
3081 unlock:
3082        mutex_unlock(&module_mutex);
3083        synchronize_sched();
3084        kfree(mod->args);
3085 free_arch_cleanup:
3086        module_arch_cleanup(mod);
3087 free_modinfo:
3088        free_modinfo(mod);
3089 free_unload:
3090        module_unload_free(mod);
3091 free_module:
3092        module_deallocate(mod, &info);
3093 free_copy:
3094        free_copy(&info);
3095        return ERR_PTR(err);
3096}
3097
3098/* Call module constructors. */
3099static void do_mod_ctors(struct module *mod)
3100{
3101#ifdef CONFIG_CONSTRUCTORS
3102        unsigned long i;
3103
3104        for (i = 0; i < mod->num_ctors; i++)
3105                mod->ctors[i]();
3106#endif
3107}
3108
3109/* This is where the real work happens */
3110SYSCALL_DEFINE3(init_module, void __user *, umod,
3111                unsigned long, len, const char __user *, uargs)
3112{
3113        struct module *mod;
3114        int ret = 0;
3115
3116        /* Must have permission */
3117        if (!capable(CAP_SYS_MODULE) || modules_disabled)
3118                return -EPERM;
3119
3120        /* Do all the hard work */
3121        mod = load_module(umod, len, uargs);
3122        if (IS_ERR(mod))
3123                return PTR_ERR(mod);
3124
3125        blocking_notifier_call_chain(&module_notify_list,
3126                        MODULE_STATE_COMING, mod);
3127
3128        /* Set RO and NX regions for core */
3129        set_section_ro_nx(mod->module_core,
3130                                mod->core_text_size,
3131                                mod->core_ro_size,
3132                                mod->core_size);
3133
3134        /* Set RO and NX regions for init */
3135        set_section_ro_nx(mod->module_init,
3136                                mod->init_text_size,
3137                                mod->init_ro_size,
3138                                mod->init_size);
3139
3140        do_mod_ctors(mod);
3141        /* Start the module */
3142        if (mod->init != NULL)
3143                ret = do_one_initcall(mod->init);
3144        if (ret < 0) {
3145                /* Init routine failed: abort.  Try to protect us from
3146                   buggy refcounters. */
3147                mod->state = MODULE_STATE_GOING;
3148                synchronize_sched();
3149                module_put(mod);
3150                blocking_notifier_call_chain(&module_notify_list,
3151                                             MODULE_STATE_GOING, mod);
3152                free_module(mod);
3153                wake_up_all(&module_wq);
3154                return ret;
3155        }
3156        if (ret > 0) {
3157                printk(KERN_WARNING
3158"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
3159"%s: loading module anyway...\n",
3160                       __func__, mod->name, ret,
3161                       __func__);
3162                dump_stack();
3163        }
3164
3165        /* Now it's a first class citizen! */
3166        mod->state = MODULE_STATE_LIVE;
3167        blocking_notifier_call_chain(&module_notify_list,
3168                                     MODULE_STATE_LIVE, mod);
3169
3170        /* We need to finish all async code before the module init sequence is done */
3171        async_synchronize_full();
3172
3173        mutex_lock(&module_mutex);
3174        /* Drop initial reference. */
3175        module_put(mod);
3176        trim_init_extable(mod);
3177#ifdef CONFIG_KALLSYMS
3178        mod->num_symtab = mod->core_num_syms;
3179        mod->symtab = mod->core_symtab;
3180        mod->strtab = mod->core_strtab;
3181#endif
3182        unset_module_init_ro_nx(mod);
3183        module_free(mod, mod->module_init);
3184        mod->module_init = NULL;
3185        mod->init_size = 0;
3186        mod->init_ro_size = 0;
3187        mod->init_text_size = 0;
3188        mutex_unlock(&module_mutex);
3189        wake_up_all(&module_wq);
3190
3191        return 0;
3192}
3193
3194static inline int within(unsigned long addr, void *start, unsigned long size)
3195{
3196        return ((void *)addr >= start && (void *)addr < start + size);
3197}
3198
3199#ifdef CONFIG_KALLSYMS
3200/*
3201 * This ignores the intensely annoying "mapping symbols" found
3202 * in ARM ELF files: $a, $t and $d.
3203 */
3204static inline int is_arm_mapping_symbol(const char *str)
3205{
3206        return str[0] == '$' && strchr("atd", str[1])
3207               && (str[2] == '\0' || str[2] == '.');
3208}
3209
3210static const char *get_ksymbol(struct module *mod,
3211                               unsigned long addr,
3212                               unsigned long *size,
3213                               unsigned long *offset)
3214{
3215        unsigned int i, best = 0;
3216        unsigned long nextval;
3217
3218        /* At worse, next value is at end of module */
3219        if (within_module_init(addr, mod))
3220                nextval = (unsigned long)mod->module_init+mod->init_text_size;
3221        else
3222                nextval = (unsigned long)mod->module_core+mod->core_text_size;
3223
3224        /* Scan for closest preceding symbol, and next symbol. (ELF
3225           starts real symbols at 1). */
3226        for (i = 1; i < mod->num_symtab; i++) {
3227                if (mod->symtab[i].st_shndx == SHN_UNDEF)
3228                        continue;
3229
3230                /* We ignore unnamed symbols: they're uninformative
3231                 * and inserted at a whim. */
3232                if (mod->symtab[i].st_value <= addr
3233                    && mod->symtab[i].st_value > mod->symtab[best].st_value
3234                    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3235                    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3236                        best = i;
3237                if (mod->symtab[i].st_value > addr
3238                    && mod->symtab[i].st_value < nextval
3239                    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3240                    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3241                        nextval = mod->symtab[i].st_value;
3242        }
3243
3244        if (!best)
3245                return NULL;
3246
3247        if (size)
3248                *size = nextval - mod->symtab[best].st_value;
3249        if (offset)
3250                *offset = addr - mod->symtab[best].st_value;
3251        return mod->strtab + mod->symtab[best].st_name;
3252}
3253
3254/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3255 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3256const char *module_address_lookup(unsigned long addr,
3257                            unsigned long *size,
3258                            unsigned long *offset,
3259                            char **modname,
3260                            char *namebuf)
3261{
3262        struct module *mod;
3263        const char *ret = NULL;
3264
3265        preempt_disable();
3266        list_for_each_entry_rcu(mod, &modules, list) {
3267                if (within_module_init(addr, mod) ||
3268                    within_module_core(addr, mod)) {
3269                        if (modname)
3270                                *modname = mod->name;
3271                        ret = get_ksymbol(mod, addr, size, offset);
3272                        break;
3273                }
3274        }
3275        /* Make a copy in here where it's safe */
3276        if (ret) {
3277                strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3278                ret = namebuf;
3279        }
3280        preempt_enable();
3281        return ret;
3282}
3283
3284int lookup_module_symbol_name(unsigned long addr, char *symname)
3285{
3286        struct module *mod;
3287
3288        preempt_disable();
3289        list_for_each_entry_rcu(mod, &modules, list) {
3290                if (within_module_init(addr, mod) ||
3291                    within_module_core(addr, mod)) {
3292                        const char *sym;
3293
3294                        sym = get_ksymbol(mod, addr, NULL, NULL);
3295                        if (!sym)
3296                                goto out;
3297                        strlcpy(symname, sym, KSYM_NAME_LEN);
3298                        preempt_enable();
3299                        return 0;
3300                }
3301        }
3302out:
3303        preempt_enable();
3304        return -ERANGE;
3305}
3306
3307int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3308                        unsigned long *offset, char *modname, char *name)
3309{
3310        struct module *mod;
3311
3312        preempt_disable();
3313        list_for_each_entry_rcu(mod, &modules, list) {
3314                if (within_module_init(addr, mod) ||
3315                    within_module_core(addr, mod)) {
3316                        const char *sym;
3317
3318                        sym = get_ksymbol(mod, addr, size, offset);
3319                        if (!sym)
3320                                goto out;
3321                        if (modname)
3322                                strlcpy(modname, mod->name, MODULE_NAME_LEN);
3323                        if (name)
3324                                strlcpy(name, sym, KSYM_NAME_LEN);
3325                        preempt_enable();
3326                        return 0;
3327                }
3328        }
3329out:
3330        preempt_enable();
3331        return -ERANGE;
3332}
3333
3334int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3335                        char *name, char *module_name, int *exported)
3336{
3337        struct module *mod;
3338
3339        preempt_disable();
3340        list_for_each_entry_rcu(mod, &modules, list) {
3341                if (symnum < mod->num_symtab) {
3342                        *value = mod->symtab[symnum].st_value;
3343                        *type = mod->symtab[symnum].st_info;
3344                        strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3345                                KSYM_NAME_LEN);
3346                        strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3347                        *exported = is_exported(name, *value, mod);
3348                        preempt_enable();
3349                        return 0;
3350                }
3351                symnum -= mod->num_symtab;
3352        }
3353        preempt_enable();
3354        return -ERANGE;
3355}
3356
3357static unsigned long mod_find_symname(struct module *mod, const char *name)
3358{
3359        unsigned int i;
3360
3361        for (i = 0; i < mod->num_symtab; i++)
3362                if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3363                    mod->symtab[i].st_info != 'U')
3364                        return mod->symtab[i].st_value;
3365        return 0;
3366}
3367
3368/* Look for this name: can be of form module:name. */
3369unsigned long module_kallsyms_lookup_name(const char *name)
3370{
3371        struct module *mod;
3372        char *colon;
3373        unsigned long ret = 0;
3374
3375        /* Don't lock: we're in enough trouble already. */
3376        preempt_disable();
3377        if ((colon = strchr(name, ':')) != NULL) {
3378                *colon = '\0';
3379                if ((mod = find_module(name)) != NULL)
3380                        ret = mod_find_symname(mod, colon+1);
3381                *colon = ':';
3382        } else {
3383                list_for_each_entry_rcu(mod, &modules, list)
3384                        if ((ret = mod_find_symname(mod, name)) != 0)
3385                                break;
3386        }
3387        preempt_enable();
3388        return ret;
3389}
3390
3391int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3392                                             struct module *, unsigned long),
3393                                   void *data)
3394{
3395        struct module *mod;
3396        unsigned int i;
3397        int ret;
3398
3399        list_for_each_entry(mod, &modules, list) {
3400                for (i = 0; i < mod->num_symtab; i++) {
3401                        ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3402                                 mod, mod->symtab[i].st_value);
3403                        if (ret != 0)
3404                                return ret;
3405                }
3406        }
3407        return 0;
3408}
3409#endif /* CONFIG_KALLSYMS */
3410
3411static char *module_flags(struct module *mod, char *buf)
3412{
3413        int bx = 0;
3414
3415        if (mod->taints ||
3416            mod->state == MODULE_STATE_GOING ||
3417            mod->state == MODULE_STATE_COMING) {
3418                buf[bx++] = '(';
3419                bx += module_flags_taint(mod, buf + bx);
3420                /* Show a - for module-is-being-unloaded */
3421                if (mod->state == MODULE_STATE_GOING)
3422                        buf[bx++] = '-';
3423                /* Show a + for module-is-being-loaded */
3424                if (mod->state == MODULE_STATE_COMING)
3425                        buf[bx++] = '+';
3426                buf[bx++] = ')';
3427        }
3428        buf[bx] = '\0';
3429
3430        return buf;
3431}
3432
3433#ifdef CONFIG_PROC_FS
3434/* Called by the /proc file system to return a list of modules. */
3435static void *m_start(struct seq_file *m, loff_t *pos)
3436{
3437        mutex_lock(&module_mutex);
3438        return seq_list_start(&modules, *pos);
3439}
3440
3441static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3442{
3443        return seq_list_next(p, &modules, pos);
3444}
3445
3446static void m_stop(struct seq_file *m, void *p)
3447{
3448        mutex_unlock(&module_mutex);
3449}
3450
3451static int m_show(struct seq_file *m, void *p)
3452{
3453        struct module *mod = list_entry(p, struct module, list);
3454        char buf[8];
3455
3456        seq_printf(m, "%s %u",
3457                   mod->name, mod->init_size + mod->core_size);
3458        print_unload_info(m, mod);
3459
3460        /* Informative for users. */
3461        seq_printf(m, " %s",
3462                   mod->state == MODULE_STATE_GOING ? "Unloading":
3463                   mod->state == MODULE_STATE_COMING ? "Loading":
3464                   "Live");
3465        /* Used by oprofile and other similar tools. */
3466        seq_printf(m, " 0x%pK", mod->module_core);
3467
3468        /* Taints info */
3469        if (mod->taints)
3470                seq_printf(m, " %s", module_flags(mod, buf));
3471
3472        seq_printf(m, "\n");
3473        return 0;
3474}
3475
3476/* Format: modulename size refcount deps address
3477
3478   Where refcount is a number or -, and deps is a comma-separated list
3479   of depends or -.
3480*/
3481static const struct seq_operations modules_op = {
3482        .start  = m_start,
3483        .next   = m_next,
3484        .stop   = m_stop,
3485        .show   = m_show
3486};
3487
3488static int modules_open(struct inode *inode, struct file *file)
3489{
3490        return seq_open(file, &modules_op);
3491}
3492
3493static const struct file_operations proc_modules_operations = {
3494        .open           = modules_open,
3495        .read           = seq_read,
3496        .llseek         = seq_lseek,
3497        .release        = seq_release,
3498};
3499
3500static int __init proc_modules_init(void)
3501{
3502        proc_create("modules", 0, NULL, &proc_modules_operations);
3503        return 0;
3504}
3505module_init(proc_modules_init);
3506#endif
3507
3508/* Given an address, look for it in the module exception tables. */
3509const struct exception_table_entry *search_module_extables(unsigned long addr)
3510{
3511        const struct exception_table_entry *e = NULL;
3512        struct module *mod;
3513
3514        preempt_disable();
3515        list_for_each_entry_rcu(mod, &modules, list) {
3516                if (mod->num_exentries == 0)
3517                        continue;
3518
3519                e = search_extable(mod->extable,
3520                                   mod->extable + mod->num_exentries - 1,
3521                                   addr);
3522                if (e)
3523                        break;
3524        }
3525        preempt_enable();
3526
3527        /* Now, if we found one, we are running inside it now, hence
3528           we cannot unload the module, hence no refcnt needed. */
3529        return e;
3530}
3531
3532/*
3533 * is_module_address - is this address inside a module?
3534 * @addr: the address to check.
3535 *
3536 * See is_module_text_address() if you simply want to see if the address
3537 * is code (not data).
3538 */
3539bool is_module_address(unsigned long addr)
3540{
3541        bool ret;
3542
3543        preempt_disable();
3544        ret = __module_address(addr) != NULL;
3545        preempt_enable();
3546
3547        return ret;
3548}
3549
3550/*
3551 * __module_address - get the module which contains an address.
3552 * @addr: the address.
3553 *
3554 * Must be called with preempt disabled or module mutex held so that
3555 * module doesn't get freed during this.
3556 */
3557struct module *__module_address(unsigned long addr)
3558{
3559        struct module *mod;
3560
3561        if (addr < module_addr_min || addr > module_addr_max)
3562                return NULL;
3563
3564        list_for_each_entry_rcu(mod, &modules, list)
3565                if (within_module_core(addr, mod)
3566                    || within_module_init(addr, mod))
3567                        return mod;
3568        return NULL;
3569}
3570EXPORT_SYMBOL_GPL(__module_address);
3571
3572/*
3573 * is_module_text_address - is this address inside module code?
3574 * @addr: the address to check.
3575 *
3576 * See is_module_address() if you simply want to see if the address is
3577 * anywhere in a module.  See kernel_text_address() for testing if an
3578 * address corresponds to kernel or module code.
3579 */
3580bool is_module_text_address(unsigned long addr)
3581{
3582        bool ret;
3583
3584        preempt_disable();
3585        ret = __module_text_address(addr) != NULL;
3586        preempt_enable();
3587
3588        return ret;
3589}
3590
3591/*
3592 * __module_text_address - get the module whose code contains an address.
3593 * @addr: the address.
3594 *
3595 * Must be called with preempt disabled or module mutex held so that
3596 * module doesn't get freed during this.
3597 */
3598struct module *__module_text_address(unsigned long addr)
3599{
3600        struct module *mod = __module_address(addr);
3601        if (mod) {
3602                /* Make sure it's within the text section. */
3603                if (!within(addr, mod->module_init, mod->init_text_size)
3604                    && !within(addr, mod->module_core, mod->core_text_size))
3605                        mod = NULL;
3606        }
3607        return mod;
3608}
3609EXPORT_SYMBOL_GPL(__module_text_address);
3610
3611/* Don't grab lock, we're oopsing. */
3612void print_modules(void)
3613{
3614        struct module *mod;
3615        char buf[8];
3616
3617        printk(KERN_DEFAULT "Modules linked in:");
3618        /* Most callers should already have preempt disabled, but make sure */
3619        preempt_disable();
3620        list_for_each_entry_rcu(mod, &modules, list)
3621                printk(" %s%s", mod->name, module_flags(mod, buf));
3622        preempt_enable();
3623        if (last_unloaded_module[0])
3624                printk(" [last unloaded: %s]", last_unloaded_module);
3625        printk("\n");
3626}
3627
3628#ifdef CONFIG_MODVERSIONS
3629/* Generate the signature for all relevant module structures here.
3630 * If these change, we don't want to try to parse the module. */
3631void module_layout(struct module *mod,
3632                   struct modversion_info *ver,
3633                   struct kernel_param *kp,
3634                   struct kernel_symbol *ks,
3635                   struct tracepoint * const *tp)
3636{
3637}
3638EXPORT_SYMBOL(module_layout);
3639#endif
3640
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