linux/kernel/module.c
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   1/*
   2   Copyright (C) 2002 Richard Henderson
   3   Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18*/
  19#include <linux/export.h>
  20#include <linux/moduleloader.h>
  21#include <linux/ftrace_event.h>
  22#include <linux/init.h>
  23#include <linux/kallsyms.h>
  24#include <linux/file.h>
  25#include <linux/fs.h>
  26#include <linux/sysfs.h>
  27#include <linux/kernel.h>
  28#include <linux/slab.h>
  29#include <linux/vmalloc.h>
  30#include <linux/elf.h>
  31#include <linux/proc_fs.h>
  32#include <linux/security.h>
  33#include <linux/seq_file.h>
  34#include <linux/syscalls.h>
  35#include <linux/fcntl.h>
  36#include <linux/rcupdate.h>
  37#include <linux/capability.h>
  38#include <linux/cpu.h>
  39#include <linux/moduleparam.h>
  40#include <linux/errno.h>
  41#include <linux/err.h>
  42#include <linux/vermagic.h>
  43#include <linux/notifier.h>
  44#include <linux/sched.h>
  45#include <linux/stop_machine.h>
  46#include <linux/device.h>
  47#include <linux/string.h>
  48#include <linux/mutex.h>
  49#include <linux/rculist.h>
  50#include <asm/uaccess.h>
  51#include <asm/cacheflush.h>
  52#include <asm/mmu_context.h>
  53#include <linux/license.h>
  54#include <asm/sections.h>
  55#include <linux/tracepoint.h>
  56#include <linux/ftrace.h>
  57#include <linux/async.h>
  58#include <linux/percpu.h>
  59#include <linux/kmemleak.h>
  60#include <linux/jump_label.h>
  61#include <linux/pfn.h>
  62#include <linux/bsearch.h>
  63#include <linux/fips.h>
  64#include <uapi/linux/module.h>
  65#include "module-internal.h"
  66
  67#define CREATE_TRACE_POINTS
  68#include <trace/events/module.h>
  69
  70#ifndef ARCH_SHF_SMALL
  71#define ARCH_SHF_SMALL 0
  72#endif
  73
  74/*
  75 * Modules' sections will be aligned on page boundaries
  76 * to ensure complete separation of code and data, but
  77 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
  78 */
  79#ifdef CONFIG_DEBUG_SET_MODULE_RONX
  80# define debug_align(X) ALIGN(X, PAGE_SIZE)
  81#else
  82# define debug_align(X) (X)
  83#endif
  84
  85/*
  86 * Given BASE and SIZE this macro calculates the number of pages the
  87 * memory regions occupies
  88 */
  89#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?         \
  90                (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
  91                         PFN_DOWN((unsigned long)BASE) + 1)     \
  92                : (0UL))
  93
  94/* If this is set, the section belongs in the init part of the module */
  95#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
  96
  97/*
  98 * Mutex protects:
  99 * 1) List of modules (also safely readable with preempt_disable),
 100 * 2) module_use links,
 101 * 3) module_addr_min/module_addr_max.
 102 * (delete uses stop_machine/add uses RCU list operations). */
 103DEFINE_MUTEX(module_mutex);
 104EXPORT_SYMBOL_GPL(module_mutex);
 105static LIST_HEAD(modules);
 106#ifdef CONFIG_KGDB_KDB
 107struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
 108#endif /* CONFIG_KGDB_KDB */
 109
 110#ifdef CONFIG_MODULE_SIG
 111#ifdef CONFIG_MODULE_SIG_FORCE
 112static bool sig_enforce = true;
 113#else
 114static bool sig_enforce = false;
 115
 116static int param_set_bool_enable_only(const char *val,
 117                                      const struct kernel_param *kp)
 118{
 119        int err;
 120        bool test;
 121        struct kernel_param dummy_kp = *kp;
 122
 123        dummy_kp.arg = &test;
 124
 125        err = param_set_bool(val, &dummy_kp);
 126        if (err)
 127                return err;
 128
 129        /* Don't let them unset it once it's set! */
 130        if (!test && sig_enforce)
 131                return -EROFS;
 132
 133        if (test)
 134                sig_enforce = true;
 135        return 0;
 136}
 137
 138static const struct kernel_param_ops param_ops_bool_enable_only = {
 139        .set = param_set_bool_enable_only,
 140        .get = param_get_bool,
 141};
 142#define param_check_bool_enable_only param_check_bool
 143
 144module_param(sig_enforce, bool_enable_only, 0644);
 145#endif /* !CONFIG_MODULE_SIG_FORCE */
 146#endif /* CONFIG_MODULE_SIG */
 147
 148/* Block module loading/unloading? */
 149int modules_disabled = 0;
 150core_param(nomodule, modules_disabled, bint, 0);
 151
 152/* Waiting for a module to finish initializing? */
 153static DECLARE_WAIT_QUEUE_HEAD(module_wq);
 154
 155static BLOCKING_NOTIFIER_HEAD(module_notify_list);
 156
 157/* Bounds of module allocation, for speeding __module_address.
 158 * Protected by module_mutex. */
 159static unsigned long module_addr_min = -1UL, module_addr_max = 0;
 160
 161int register_module_notifier(struct notifier_block * nb)
 162{
 163        return blocking_notifier_chain_register(&module_notify_list, nb);
 164}
 165EXPORT_SYMBOL(register_module_notifier);
 166
 167int unregister_module_notifier(struct notifier_block * nb)
 168{
 169        return blocking_notifier_chain_unregister(&module_notify_list, nb);
 170}
 171EXPORT_SYMBOL(unregister_module_notifier);
 172
 173struct load_info {
 174        Elf_Ehdr *hdr;
 175        unsigned long len;
 176        Elf_Shdr *sechdrs;
 177        char *secstrings, *strtab;
 178        unsigned long symoffs, stroffs;
 179        struct _ddebug *debug;
 180        unsigned int num_debug;
 181        bool sig_ok;
 182        struct {
 183                unsigned int sym, str, mod, vers, info, pcpu;
 184        } index;
 185};
 186
 187/* We require a truly strong try_module_get(): 0 means failure due to
 188   ongoing or failed initialization etc. */
 189static inline int strong_try_module_get(struct module *mod)
 190{
 191        BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
 192        if (mod && mod->state == MODULE_STATE_COMING)
 193                return -EBUSY;
 194        if (try_module_get(mod))
 195                return 0;
 196        else
 197                return -ENOENT;
 198}
 199
 200static inline void add_taint_module(struct module *mod, unsigned flag,
 201                                    enum lockdep_ok lockdep_ok)
 202{
 203        add_taint(flag, lockdep_ok);
 204        mod->taints |= (1U << flag);
 205}
 206
 207/*
 208 * A thread that wants to hold a reference to a module only while it
 209 * is running can call this to safely exit.  nfsd and lockd use this.
 210 */
 211void __module_put_and_exit(struct module *mod, long code)
 212{
 213        module_put(mod);
 214        do_exit(code);
 215}
 216EXPORT_SYMBOL(__module_put_and_exit);
 217
 218/* Find a module section: 0 means not found. */
 219static unsigned int find_sec(const struct load_info *info, const char *name)
 220{
 221        unsigned int i;
 222
 223        for (i = 1; i < info->hdr->e_shnum; i++) {
 224                Elf_Shdr *shdr = &info->sechdrs[i];
 225                /* Alloc bit cleared means "ignore it." */
 226                if ((shdr->sh_flags & SHF_ALLOC)
 227                    && strcmp(info->secstrings + shdr->sh_name, name) == 0)
 228                        return i;
 229        }
 230        return 0;
 231}
 232
 233/* Find a module section, or NULL. */
 234static void *section_addr(const struct load_info *info, const char *name)
 235{
 236        /* Section 0 has sh_addr 0. */
 237        return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
 238}
 239
 240/* Find a module section, or NULL.  Fill in number of "objects" in section. */
 241static void *section_objs(const struct load_info *info,
 242                          const char *name,
 243                          size_t object_size,
 244                          unsigned int *num)
 245{
 246        unsigned int sec = find_sec(info, name);
 247
 248        /* Section 0 has sh_addr 0 and sh_size 0. */
 249        *num = info->sechdrs[sec].sh_size / object_size;
 250        return (void *)info->sechdrs[sec].sh_addr;
 251}
 252
 253/* Provided by the linker */
 254extern const struct kernel_symbol __start___ksymtab[];
 255extern const struct kernel_symbol __stop___ksymtab[];
 256extern const struct kernel_symbol __start___ksymtab_gpl[];
 257extern const struct kernel_symbol __stop___ksymtab_gpl[];
 258extern const struct kernel_symbol __start___ksymtab_gpl_future[];
 259extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
 260extern const unsigned long __start___kcrctab[];
 261extern const unsigned long __start___kcrctab_gpl[];
 262extern const unsigned long __start___kcrctab_gpl_future[];
 263#ifdef CONFIG_UNUSED_SYMBOLS
 264extern const struct kernel_symbol __start___ksymtab_unused[];
 265extern const struct kernel_symbol __stop___ksymtab_unused[];
 266extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
 267extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
 268extern const unsigned long __start___kcrctab_unused[];
 269extern const unsigned long __start___kcrctab_unused_gpl[];
 270#endif
 271
 272#ifndef CONFIG_MODVERSIONS
 273#define symversion(base, idx) NULL
 274#else
 275#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
 276#endif
 277
 278static bool each_symbol_in_section(const struct symsearch *arr,
 279                                   unsigned int arrsize,
 280                                   struct module *owner,
 281                                   bool (*fn)(const struct symsearch *syms,
 282                                              struct module *owner,
 283                                              void *data),
 284                                   void *data)
 285{
 286        unsigned int j;
 287
 288        for (j = 0; j < arrsize; j++) {
 289                if (fn(&arr[j], owner, data))
 290                        return true;
 291        }
 292
 293        return false;
 294}
 295
 296/* Returns true as soon as fn returns true, otherwise false. */
 297bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 298                                    struct module *owner,
 299                                    void *data),
 300                         void *data)
 301{
 302        struct module *mod;
 303        static const struct symsearch arr[] = {
 304                { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
 305                  NOT_GPL_ONLY, false },
 306                { __start___ksymtab_gpl, __stop___ksymtab_gpl,
 307                  __start___kcrctab_gpl,
 308                  GPL_ONLY, false },
 309                { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
 310                  __start___kcrctab_gpl_future,
 311                  WILL_BE_GPL_ONLY, false },
 312#ifdef CONFIG_UNUSED_SYMBOLS
 313                { __start___ksymtab_unused, __stop___ksymtab_unused,
 314                  __start___kcrctab_unused,
 315                  NOT_GPL_ONLY, true },
 316                { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
 317                  __start___kcrctab_unused_gpl,
 318                  GPL_ONLY, true },
 319#endif
 320        };
 321
 322        if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
 323                return true;
 324
 325        list_for_each_entry_rcu(mod, &modules, list) {
 326                struct symsearch arr[] = {
 327                        { mod->syms, mod->syms + mod->num_syms, mod->crcs,
 328                          NOT_GPL_ONLY, false },
 329                        { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
 330                          mod->gpl_crcs,
 331                          GPL_ONLY, false },
 332                        { mod->gpl_future_syms,
 333                          mod->gpl_future_syms + mod->num_gpl_future_syms,
 334                          mod->gpl_future_crcs,
 335                          WILL_BE_GPL_ONLY, false },
 336#ifdef CONFIG_UNUSED_SYMBOLS
 337                        { mod->unused_syms,
 338                          mod->unused_syms + mod->num_unused_syms,
 339                          mod->unused_crcs,
 340                          NOT_GPL_ONLY, true },
 341                        { mod->unused_gpl_syms,
 342                          mod->unused_gpl_syms + mod->num_unused_gpl_syms,
 343                          mod->unused_gpl_crcs,
 344                          GPL_ONLY, true },
 345#endif
 346                };
 347
 348                if (mod->state == MODULE_STATE_UNFORMED)
 349                        continue;
 350
 351                if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
 352                        return true;
 353        }
 354        return false;
 355}
 356EXPORT_SYMBOL_GPL(each_symbol_section);
 357
 358struct find_symbol_arg {
 359        /* Input */
 360        const char *name;
 361        bool gplok;
 362        bool warn;
 363
 364        /* Output */
 365        struct module *owner;
 366        const unsigned long *crc;
 367        const struct kernel_symbol *sym;
 368};
 369
 370static bool check_symbol(const struct symsearch *syms,
 371                                 struct module *owner,
 372                                 unsigned int symnum, void *data)
 373{
 374        struct find_symbol_arg *fsa = data;
 375
 376        if (!fsa->gplok) {
 377                if (syms->licence == GPL_ONLY)
 378                        return false;
 379                if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
 380                        printk(KERN_WARNING "Symbol %s is being used "
 381                               "by a non-GPL module, which will not "
 382                               "be allowed in the future\n", fsa->name);
 383                }
 384        }
 385
 386#ifdef CONFIG_UNUSED_SYMBOLS
 387        if (syms->unused && fsa->warn) {
 388                printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
 389                       "however this module is using it.\n", fsa->name);
 390                printk(KERN_WARNING
 391                       "This symbol will go away in the future.\n");
 392                printk(KERN_WARNING
 393                       "Please evalute if this is the right api to use and if "
 394                       "it really is, submit a report the linux kernel "
 395                       "mailinglist together with submitting your code for "
 396                       "inclusion.\n");
 397        }
 398#endif
 399
 400        fsa->owner = owner;
 401        fsa->crc = symversion(syms->crcs, symnum);
 402        fsa->sym = &syms->start[symnum];
 403        return true;
 404}
 405
 406static int cmp_name(const void *va, const void *vb)
 407{
 408        const char *a;
 409        const struct kernel_symbol *b;
 410        a = va; b = vb;
 411        return strcmp(a, b->name);
 412}
 413
 414static bool find_symbol_in_section(const struct symsearch *syms,
 415                                   struct module *owner,
 416                                   void *data)
 417{
 418        struct find_symbol_arg *fsa = data;
 419        struct kernel_symbol *sym;
 420
 421        sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
 422                        sizeof(struct kernel_symbol), cmp_name);
 423
 424        if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
 425                return true;
 426
 427        return false;
 428}
 429
 430/* Find a symbol and return it, along with, (optional) crc and
 431 * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
 432const struct kernel_symbol *find_symbol(const char *name,
 433                                        struct module **owner,
 434                                        const unsigned long **crc,
 435                                        bool gplok,
 436                                        bool warn)
 437{
 438        struct find_symbol_arg fsa;
 439
 440        fsa.name = name;
 441        fsa.gplok = gplok;
 442        fsa.warn = warn;
 443
 444        if (each_symbol_section(find_symbol_in_section, &fsa)) {
 445                if (owner)
 446                        *owner = fsa.owner;
 447                if (crc)
 448                        *crc = fsa.crc;
 449                return fsa.sym;
 450        }
 451
 452        pr_debug("Failed to find symbol %s\n", name);
 453        return NULL;
 454}
 455EXPORT_SYMBOL_GPL(find_symbol);
 456
 457/* Search for module by name: must hold module_mutex. */
 458static struct module *find_module_all(const char *name,
 459                                      bool even_unformed)
 460{
 461        struct module *mod;
 462
 463        list_for_each_entry(mod, &modules, list) {
 464                if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
 465                        continue;
 466                if (strcmp(mod->name, name) == 0)
 467                        return mod;
 468        }
 469        return NULL;
 470}
 471
 472struct module *find_module(const char *name)
 473{
 474        return find_module_all(name, false);
 475}
 476EXPORT_SYMBOL_GPL(find_module);
 477
 478#ifdef CONFIG_SMP
 479
 480static inline void __percpu *mod_percpu(struct module *mod)
 481{
 482        return mod->percpu;
 483}
 484
 485static int percpu_modalloc(struct module *mod,
 486                           unsigned long size, unsigned long align)
 487{
 488        if (align > PAGE_SIZE) {
 489                printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
 490                       mod->name, align, PAGE_SIZE);
 491                align = PAGE_SIZE;
 492        }
 493
 494        mod->percpu = __alloc_reserved_percpu(size, align);
 495        if (!mod->percpu) {
 496                printk(KERN_WARNING
 497                       "%s: Could not allocate %lu bytes percpu data\n",
 498                       mod->name, size);
 499                return -ENOMEM;
 500        }
 501        mod->percpu_size = size;
 502        return 0;
 503}
 504
 505static void percpu_modfree(struct module *mod)
 506{
 507        free_percpu(mod->percpu);
 508}
 509
 510static unsigned int find_pcpusec(struct load_info *info)
 511{
 512        return find_sec(info, ".data..percpu");
 513}
 514
 515static void percpu_modcopy(struct module *mod,
 516                           const void *from, unsigned long size)
 517{
 518        int cpu;
 519
 520        for_each_possible_cpu(cpu)
 521                memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
 522}
 523
 524/**
 525 * is_module_percpu_address - test whether address is from module static percpu
 526 * @addr: address to test
 527 *
 528 * Test whether @addr belongs to module static percpu area.
 529 *
 530 * RETURNS:
 531 * %true if @addr is from module static percpu area
 532 */
 533bool is_module_percpu_address(unsigned long addr)
 534{
 535        struct module *mod;
 536        unsigned int cpu;
 537
 538        preempt_disable();
 539
 540        list_for_each_entry_rcu(mod, &modules, list) {
 541                if (mod->state == MODULE_STATE_UNFORMED)
 542                        continue;
 543                if (!mod->percpu_size)
 544                        continue;
 545                for_each_possible_cpu(cpu) {
 546                        void *start = per_cpu_ptr(mod->percpu, cpu);
 547
 548                        if ((void *)addr >= start &&
 549                            (void *)addr < start + mod->percpu_size) {
 550                                preempt_enable();
 551                                return true;
 552                        }
 553                }
 554        }
 555
 556        preempt_enable();
 557        return false;
 558}
 559
 560#else /* ... !CONFIG_SMP */
 561
 562static inline void __percpu *mod_percpu(struct module *mod)
 563{
 564        return NULL;
 565}
 566static inline int percpu_modalloc(struct module *mod,
 567                                  unsigned long size, unsigned long align)
 568{
 569        return -ENOMEM;
 570}
 571static inline void percpu_modfree(struct module *mod)
 572{
 573}
 574static unsigned int find_pcpusec(struct load_info *info)
 575{
 576        return 0;
 577}
 578static inline void percpu_modcopy(struct module *mod,
 579                                  const void *from, unsigned long size)
 580{
 581        /* pcpusec should be 0, and size of that section should be 0. */
 582        BUG_ON(size != 0);
 583}
 584bool is_module_percpu_address(unsigned long addr)
 585{
 586        return false;
 587}
 588
 589#endif /* CONFIG_SMP */
 590
 591#define MODINFO_ATTR(field)     \
 592static void setup_modinfo_##field(struct module *mod, const char *s)  \
 593{                                                                     \
 594        mod->field = kstrdup(s, GFP_KERNEL);                          \
 595}                                                                     \
 596static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
 597                        struct module_kobject *mk, char *buffer)      \
 598{                                                                     \
 599        return sprintf(buffer, "%s\n", mk->mod->field);               \
 600}                                                                     \
 601static int modinfo_##field##_exists(struct module *mod)               \
 602{                                                                     \
 603        return mod->field != NULL;                                    \
 604}                                                                     \
 605static void free_modinfo_##field(struct module *mod)                  \
 606{                                                                     \
 607        kfree(mod->field);                                            \
 608        mod->field = NULL;                                            \
 609}                                                                     \
 610static struct module_attribute modinfo_##field = {                    \
 611        .attr = { .name = __stringify(field), .mode = 0444 },         \
 612        .show = show_modinfo_##field,                                 \
 613        .setup = setup_modinfo_##field,                               \
 614        .test = modinfo_##field##_exists,                             \
 615        .free = free_modinfo_##field,                                 \
 616};
 617
 618MODINFO_ATTR(version);
 619MODINFO_ATTR(srcversion);
 620
 621static char last_unloaded_module[MODULE_NAME_LEN+1];
 622
 623#ifdef CONFIG_MODULE_UNLOAD
 624
 625EXPORT_TRACEPOINT_SYMBOL(module_get);
 626
 627/* Init the unload section of the module. */
 628static int module_unload_init(struct module *mod)
 629{
 630        mod->refptr = alloc_percpu(struct module_ref);
 631        if (!mod->refptr)
 632                return -ENOMEM;
 633
 634        INIT_LIST_HEAD(&mod->source_list);
 635        INIT_LIST_HEAD(&mod->target_list);
 636
 637        /* Hold reference count during initialization. */
 638        __this_cpu_write(mod->refptr->incs, 1);
 639        /* Backwards compatibility macros put refcount during init. */
 640        mod->waiter = current;
 641
 642        return 0;
 643}
 644
 645/* Does a already use b? */
 646static int already_uses(struct module *a, struct module *b)
 647{
 648        struct module_use *use;
 649
 650        list_for_each_entry(use, &b->source_list, source_list) {
 651                if (use->source == a) {
 652                        pr_debug("%s uses %s!\n", a->name, b->name);
 653                        return 1;
 654                }
 655        }
 656        pr_debug("%s does not use %s!\n", a->name, b->name);
 657        return 0;
 658}
 659
 660/*
 661 * Module a uses b
 662 *  - we add 'a' as a "source", 'b' as a "target" of module use
 663 *  - the module_use is added to the list of 'b' sources (so
 664 *    'b' can walk the list to see who sourced them), and of 'a'
 665 *    targets (so 'a' can see what modules it targets).
 666 */
 667static int add_module_usage(struct module *a, struct module *b)
 668{
 669        struct module_use *use;
 670
 671        pr_debug("Allocating new usage for %s.\n", a->name);
 672        use = kmalloc(sizeof(*use), GFP_ATOMIC);
 673        if (!use) {
 674                printk(KERN_WARNING "%s: out of memory loading\n", a->name);
 675                return -ENOMEM;
 676        }
 677
 678        use->source = a;
 679        use->target = b;
 680        list_add(&use->source_list, &b->source_list);
 681        list_add(&use->target_list, &a->target_list);
 682        return 0;
 683}
 684
 685/* Module a uses b: caller needs module_mutex() */
 686int ref_module(struct module *a, struct module *b)
 687{
 688        int err;
 689
 690        if (b == NULL || already_uses(a, b))
 691                return 0;
 692
 693        /* If module isn't available, we fail. */
 694        err = strong_try_module_get(b);
 695        if (err)
 696                return err;
 697
 698        err = add_module_usage(a, b);
 699        if (err) {
 700                module_put(b);
 701                return err;
 702        }
 703        return 0;
 704}
 705EXPORT_SYMBOL_GPL(ref_module);
 706
 707/* Clear the unload stuff of the module. */
 708static void module_unload_free(struct module *mod)
 709{
 710        struct module_use *use, *tmp;
 711
 712        mutex_lock(&module_mutex);
 713        list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
 714                struct module *i = use->target;
 715                pr_debug("%s unusing %s\n", mod->name, i->name);
 716                module_put(i);
 717                list_del(&use->source_list);
 718                list_del(&use->target_list);
 719                kfree(use);
 720        }
 721        mutex_unlock(&module_mutex);
 722
 723        free_percpu(mod->refptr);
 724}
 725
 726#ifdef CONFIG_MODULE_FORCE_UNLOAD
 727static inline int try_force_unload(unsigned int flags)
 728{
 729        int ret = (flags & O_TRUNC);
 730        if (ret)
 731                add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
 732        return ret;
 733}
 734#else
 735static inline int try_force_unload(unsigned int flags)
 736{
 737        return 0;
 738}
 739#endif /* CONFIG_MODULE_FORCE_UNLOAD */
 740
 741struct stopref
 742{
 743        struct module *mod;
 744        int flags;
 745        int *forced;
 746};
 747
 748/* Whole machine is stopped with interrupts off when this runs. */
 749static int __try_stop_module(void *_sref)
 750{
 751        struct stopref *sref = _sref;
 752
 753        /* If it's not unused, quit unless we're forcing. */
 754        if (module_refcount(sref->mod) != 0) {
 755                if (!(*sref->forced = try_force_unload(sref->flags)))
 756                        return -EWOULDBLOCK;
 757        }
 758
 759        /* Mark it as dying. */
 760        sref->mod->state = MODULE_STATE_GOING;
 761        return 0;
 762}
 763
 764static int try_stop_module(struct module *mod, int flags, int *forced)
 765{
 766        if (flags & O_NONBLOCK) {
 767                struct stopref sref = { mod, flags, forced };
 768
 769                return stop_machine(__try_stop_module, &sref, NULL);
 770        } else {
 771                /* We don't need to stop the machine for this. */
 772                mod->state = MODULE_STATE_GOING;
 773                synchronize_sched();
 774                return 0;
 775        }
 776}
 777
 778unsigned long module_refcount(struct module *mod)
 779{
 780        unsigned long incs = 0, decs = 0;
 781        int cpu;
 782
 783        for_each_possible_cpu(cpu)
 784                decs += per_cpu_ptr(mod->refptr, cpu)->decs;
 785        /*
 786         * ensure the incs are added up after the decs.
 787         * module_put ensures incs are visible before decs with smp_wmb.
 788         *
 789         * This 2-count scheme avoids the situation where the refcount
 790         * for CPU0 is read, then CPU0 increments the module refcount,
 791         * then CPU1 drops that refcount, then the refcount for CPU1 is
 792         * read. We would record a decrement but not its corresponding
 793         * increment so we would see a low count (disaster).
 794         *
 795         * Rare situation? But module_refcount can be preempted, and we
 796         * might be tallying up 4096+ CPUs. So it is not impossible.
 797         */
 798        smp_rmb();
 799        for_each_possible_cpu(cpu)
 800                incs += per_cpu_ptr(mod->refptr, cpu)->incs;
 801        return incs - decs;
 802}
 803EXPORT_SYMBOL(module_refcount);
 804
 805/* This exists whether we can unload or not */
 806static void free_module(struct module *mod);
 807
 808static void wait_for_zero_refcount(struct module *mod)
 809{
 810        /* Since we might sleep for some time, release the mutex first */
 811        mutex_unlock(&module_mutex);
 812        for (;;) {
 813                pr_debug("Looking at refcount...\n");
 814                set_current_state(TASK_UNINTERRUPTIBLE);
 815                if (module_refcount(mod) == 0)
 816                        break;
 817                schedule();
 818        }
 819        current->state = TASK_RUNNING;
 820        mutex_lock(&module_mutex);
 821}
 822
 823SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
 824                unsigned int, flags)
 825{
 826        struct module *mod;
 827        char name[MODULE_NAME_LEN];
 828        int ret, forced = 0;
 829
 830        if (!capable(CAP_SYS_MODULE) || modules_disabled)
 831                return -EPERM;
 832
 833        if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
 834                return -EFAULT;
 835        name[MODULE_NAME_LEN-1] = '\0';
 836
 837        if (mutex_lock_interruptible(&module_mutex) != 0)
 838                return -EINTR;
 839
 840        mod = find_module(name);
 841        if (!mod) {
 842                ret = -ENOENT;
 843                goto out;
 844        }
 845
 846        if (!list_empty(&mod->source_list)) {
 847                /* Other modules depend on us: get rid of them first. */
 848                ret = -EWOULDBLOCK;
 849                goto out;
 850        }
 851
 852        /* Doing init or already dying? */
 853        if (mod->state != MODULE_STATE_LIVE) {
 854                /* FIXME: if (force), slam module count and wake up
 855                   waiter --RR */
 856                pr_debug("%s already dying\n", mod->name);
 857                ret = -EBUSY;
 858                goto out;
 859        }
 860
 861        /* If it has an init func, it must have an exit func to unload */
 862        if (mod->init && !mod->exit) {
 863                forced = try_force_unload(flags);
 864                if (!forced) {
 865                        /* This module can't be removed */
 866                        ret = -EBUSY;
 867                        goto out;
 868                }
 869        }
 870
 871        /* Set this up before setting mod->state */
 872        mod->waiter = current;
 873
 874        /* Stop the machine so refcounts can't move and disable module. */
 875        ret = try_stop_module(mod, flags, &forced);
 876        if (ret != 0)
 877                goto out;
 878
 879        /* Never wait if forced. */
 880        if (!forced && module_refcount(mod) != 0)
 881                wait_for_zero_refcount(mod);
 882
 883        mutex_unlock(&module_mutex);
 884        /* Final destruction now no one is using it. */
 885        if (mod->exit != NULL)
 886                mod->exit();
 887        blocking_notifier_call_chain(&module_notify_list,
 888                                     MODULE_STATE_GOING, mod);
 889        async_synchronize_full();
 890
 891        /* Store the name of the last unloaded module for diagnostic purposes */
 892        strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
 893
 894        free_module(mod);
 895        return 0;
 896out:
 897        mutex_unlock(&module_mutex);
 898        return ret;
 899}
 900
 901static inline void print_unload_info(struct seq_file *m, struct module *mod)
 902{
 903        struct module_use *use;
 904        int printed_something = 0;
 905
 906        seq_printf(m, " %lu ", module_refcount(mod));
 907
 908        /* Always include a trailing , so userspace can differentiate
 909           between this and the old multi-field proc format. */
 910        list_for_each_entry(use, &mod->source_list, source_list) {
 911                printed_something = 1;
 912                seq_printf(m, "%s,", use->source->name);
 913        }
 914
 915        if (mod->init != NULL && mod->exit == NULL) {
 916                printed_something = 1;
 917                seq_printf(m, "[permanent],");
 918        }
 919
 920        if (!printed_something)
 921                seq_printf(m, "-");
 922}
 923
 924void __symbol_put(const char *symbol)
 925{
 926        struct module *owner;
 927
 928        preempt_disable();
 929        if (!find_symbol(symbol, &owner, NULL, true, false))
 930                BUG();
 931        module_put(owner);
 932        preempt_enable();
 933}
 934EXPORT_SYMBOL(__symbol_put);
 935
 936/* Note this assumes addr is a function, which it currently always is. */
 937void symbol_put_addr(void *addr)
 938{
 939        struct module *modaddr;
 940        unsigned long a = (unsigned long)dereference_function_descriptor(addr);
 941
 942        if (core_kernel_text(a))
 943                return;
 944
 945        /* module_text_address is safe here: we're supposed to have reference
 946         * to module from symbol_get, so it can't go away. */
 947        modaddr = __module_text_address(a);
 948        BUG_ON(!modaddr);
 949        module_put(modaddr);
 950}
 951EXPORT_SYMBOL_GPL(symbol_put_addr);
 952
 953static ssize_t show_refcnt(struct module_attribute *mattr,
 954                           struct module_kobject *mk, char *buffer)
 955{
 956        return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
 957}
 958
 959static struct module_attribute modinfo_refcnt =
 960        __ATTR(refcnt, 0444, show_refcnt, NULL);
 961
 962void __module_get(struct module *module)
 963{
 964        if (module) {
 965                preempt_disable();
 966                __this_cpu_inc(module->refptr->incs);
 967                trace_module_get(module, _RET_IP_);
 968                preempt_enable();
 969        }
 970}
 971EXPORT_SYMBOL(__module_get);
 972
 973bool try_module_get(struct module *module)
 974{
 975        bool ret = true;
 976
 977        if (module) {
 978                preempt_disable();
 979
 980                if (likely(module_is_live(module))) {
 981                        __this_cpu_inc(module->refptr->incs);
 982                        trace_module_get(module, _RET_IP_);
 983                } else
 984                        ret = false;
 985
 986                preempt_enable();
 987        }
 988        return ret;
 989}
 990EXPORT_SYMBOL(try_module_get);
 991
 992void module_put(struct module *module)
 993{
 994        if (module) {
 995                preempt_disable();
 996                smp_wmb(); /* see comment in module_refcount */
 997                __this_cpu_inc(module->refptr->decs);
 998
 999                trace_module_put(module, _RET_IP_);
1000                /* Maybe they're waiting for us to drop reference? */
1001                if (unlikely(!module_is_live(module)))
1002                        wake_up_process(module->waiter);
1003                preempt_enable();
1004        }
1005}
1006EXPORT_SYMBOL(module_put);
1007
1008#else /* !CONFIG_MODULE_UNLOAD */
1009static inline void print_unload_info(struct seq_file *m, struct module *mod)
1010{
1011        /* We don't know the usage count, or what modules are using. */
1012        seq_printf(m, " - -");
1013}
1014
1015static inline void module_unload_free(struct module *mod)
1016{
1017}
1018
1019int ref_module(struct module *a, struct module *b)
1020{
1021        return strong_try_module_get(b);
1022}
1023EXPORT_SYMBOL_GPL(ref_module);
1024
1025static inline int module_unload_init(struct module *mod)
1026{
1027        return 0;
1028}
1029#endif /* CONFIG_MODULE_UNLOAD */
1030
1031static size_t module_flags_taint(struct module *mod, char *buf)
1032{
1033        size_t l = 0;
1034
1035        if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1036                buf[l++] = 'P';
1037        if (mod->taints & (1 << TAINT_OOT_MODULE))
1038                buf[l++] = 'O';
1039        if (mod->taints & (1 << TAINT_FORCED_MODULE))
1040                buf[l++] = 'F';
1041        if (mod->taints & (1 << TAINT_CRAP))
1042                buf[l++] = 'C';
1043        /*
1044         * TAINT_FORCED_RMMOD: could be added.
1045         * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1046         * apply to modules.
1047         */
1048        return l;
1049}
1050
1051static ssize_t show_initstate(struct module_attribute *mattr,
1052                              struct module_kobject *mk, char *buffer)
1053{
1054        const char *state = "unknown";
1055
1056        switch (mk->mod->state) {
1057        case MODULE_STATE_LIVE:
1058                state = "live";
1059                break;
1060        case MODULE_STATE_COMING:
1061                state = "coming";
1062                break;
1063        case MODULE_STATE_GOING:
1064                state = "going";
1065                break;
1066        default:
1067                BUG();
1068        }
1069        return sprintf(buffer, "%s\n", state);
1070}
1071
1072static struct module_attribute modinfo_initstate =
1073        __ATTR(initstate, 0444, show_initstate, NULL);
1074
1075static ssize_t store_uevent(struct module_attribute *mattr,
1076                            struct module_kobject *mk,
1077                            const char *buffer, size_t count)
1078{
1079        enum kobject_action action;
1080
1081        if (kobject_action_type(buffer, count, &action) == 0)
1082                kobject_uevent(&mk->kobj, action);
1083        return count;
1084}
1085
1086struct module_attribute module_uevent =
1087        __ATTR(uevent, 0200, NULL, store_uevent);
1088
1089static ssize_t show_coresize(struct module_attribute *mattr,
1090                             struct module_kobject *mk, char *buffer)
1091{
1092        return sprintf(buffer, "%u\n", mk->mod->core_size);
1093}
1094
1095static struct module_attribute modinfo_coresize =
1096        __ATTR(coresize, 0444, show_coresize, NULL);
1097
1098static ssize_t show_initsize(struct module_attribute *mattr,
1099                             struct module_kobject *mk, char *buffer)
1100{
1101        return sprintf(buffer, "%u\n", mk->mod->init_size);
1102}
1103
1104static struct module_attribute modinfo_initsize =
1105        __ATTR(initsize, 0444, show_initsize, NULL);
1106
1107static ssize_t show_taint(struct module_attribute *mattr,
1108                          struct module_kobject *mk, char *buffer)
1109{
1110        size_t l;
1111
1112        l = module_flags_taint(mk->mod, buffer);
1113        buffer[l++] = '\n';
1114        return l;
1115}
1116
1117static struct module_attribute modinfo_taint =
1118        __ATTR(taint, 0444, show_taint, NULL);
1119
1120static struct module_attribute *modinfo_attrs[] = {
1121        &module_uevent,
1122        &modinfo_version,
1123        &modinfo_srcversion,
1124        &modinfo_initstate,
1125        &modinfo_coresize,
1126        &modinfo_initsize,
1127        &modinfo_taint,
1128#ifdef CONFIG_MODULE_UNLOAD
1129        &modinfo_refcnt,
1130#endif
1131        NULL,
1132};
1133
1134static const char vermagic[] = VERMAGIC_STRING;
1135
1136static int try_to_force_load(struct module *mod, const char *reason)
1137{
1138#ifdef CONFIG_MODULE_FORCE_LOAD
1139        if (!test_taint(TAINT_FORCED_MODULE))
1140                printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1141                       mod->name, reason);
1142        add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1143        return 0;
1144#else
1145        return -ENOEXEC;
1146#endif
1147}
1148
1149#ifdef CONFIG_MODVERSIONS
1150/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1151static unsigned long maybe_relocated(unsigned long crc,
1152                                     const struct module *crc_owner)
1153{
1154#ifdef ARCH_RELOCATES_KCRCTAB
1155        if (crc_owner == NULL)
1156                return crc - (unsigned long)reloc_start;
1157#endif
1158        return crc;
1159}
1160
1161static int check_version(Elf_Shdr *sechdrs,
1162                         unsigned int versindex,
1163                         const char *symname,
1164                         struct module *mod, 
1165                         const unsigned long *crc,
1166                         const struct module *crc_owner)
1167{
1168        unsigned int i, num_versions;
1169        struct modversion_info *versions;
1170
1171        /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1172        if (!crc)
1173                return 1;
1174
1175        /* No versions at all?  modprobe --force does this. */
1176        if (versindex == 0)
1177                return try_to_force_load(mod, symname) == 0;
1178
1179        versions = (void *) sechdrs[versindex].sh_addr;
1180        num_versions = sechdrs[versindex].sh_size
1181                / sizeof(struct modversion_info);
1182
1183        for (i = 0; i < num_versions; i++) {
1184                if (strcmp(versions[i].name, symname) != 0)
1185                        continue;
1186
1187                if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1188                        return 1;
1189                pr_debug("Found checksum %lX vs module %lX\n",
1190                       maybe_relocated(*crc, crc_owner), versions[i].crc);
1191                goto bad_version;
1192        }
1193
1194        printk(KERN_WARNING "%s: no symbol version for %s\n",
1195               mod->name, symname);
1196        return 0;
1197
1198bad_version:
1199        printk("%s: disagrees about version of symbol %s\n",
1200               mod->name, symname);
1201        return 0;
1202}
1203
1204static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1205                                          unsigned int versindex,
1206                                          struct module *mod)
1207{
1208        const unsigned long *crc;
1209
1210        /* Since this should be found in kernel (which can't be removed),
1211         * no locking is necessary. */
1212        if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1213                         &crc, true, false))
1214                BUG();
1215        return check_version(sechdrs, versindex,
1216                             VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1217                             NULL);
1218}
1219
1220/* First part is kernel version, which we ignore if module has crcs. */
1221static inline int same_magic(const char *amagic, const char *bmagic,
1222                             bool has_crcs)
1223{
1224        if (has_crcs) {
1225                amagic += strcspn(amagic, " ");
1226                bmagic += strcspn(bmagic, " ");
1227        }
1228        return strcmp(amagic, bmagic) == 0;
1229}
1230#else
1231static inline int check_version(Elf_Shdr *sechdrs,
1232                                unsigned int versindex,
1233                                const char *symname,
1234                                struct module *mod, 
1235                                const unsigned long *crc,
1236                                const struct module *crc_owner)
1237{
1238        return 1;
1239}
1240
1241static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1242                                          unsigned int versindex,
1243                                          struct module *mod)
1244{
1245        return 1;
1246}
1247
1248static inline int same_magic(const char *amagic, const char *bmagic,
1249                             bool has_crcs)
1250{
1251        return strcmp(amagic, bmagic) == 0;
1252}
1253#endif /* CONFIG_MODVERSIONS */
1254
1255/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1256static const struct kernel_symbol *resolve_symbol(struct module *mod,
1257                                                  const struct load_info *info,
1258                                                  const char *name,
1259                                                  char ownername[])
1260{
1261        struct module *owner;
1262        const struct kernel_symbol *sym;
1263        const unsigned long *crc;
1264        int err;
1265
1266        mutex_lock(&module_mutex);
1267        sym = find_symbol(name, &owner, &crc,
1268                          !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1269        if (!sym)
1270                goto unlock;
1271
1272        if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1273                           owner)) {
1274                sym = ERR_PTR(-EINVAL);
1275                goto getname;
1276        }
1277
1278        err = ref_module(mod, owner);
1279        if (err) {
1280                sym = ERR_PTR(err);
1281                goto getname;
1282        }
1283
1284getname:
1285        /* We must make copy under the lock if we failed to get ref. */
1286        strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1287unlock:
1288        mutex_unlock(&module_mutex);
1289        return sym;
1290}
1291
1292static const struct kernel_symbol *
1293resolve_symbol_wait(struct module *mod,
1294                    const struct load_info *info,
1295                    const char *name)
1296{
1297        const struct kernel_symbol *ksym;
1298        char owner[MODULE_NAME_LEN];
1299
1300        if (wait_event_interruptible_timeout(module_wq,
1301                        !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1302                        || PTR_ERR(ksym) != -EBUSY,
1303                                             30 * HZ) <= 0) {
1304                printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1305                       mod->name, owner);
1306        }
1307        return ksym;
1308}
1309
1310/*
1311 * /sys/module/foo/sections stuff
1312 * J. Corbet <corbet@lwn.net>
1313 */
1314#ifdef CONFIG_SYSFS
1315
1316#ifdef CONFIG_KALLSYMS
1317static inline bool sect_empty(const Elf_Shdr *sect)
1318{
1319        return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1320}
1321
1322struct module_sect_attr
1323{
1324        struct module_attribute mattr;
1325        char *name;
1326        unsigned long address;
1327};
1328
1329struct module_sect_attrs
1330{
1331        struct attribute_group grp;
1332        unsigned int nsections;
1333        struct module_sect_attr attrs[0];
1334};
1335
1336static ssize_t module_sect_show(struct module_attribute *mattr,
1337                                struct module_kobject *mk, char *buf)
1338{
1339        struct module_sect_attr *sattr =
1340                container_of(mattr, struct module_sect_attr, mattr);
1341        return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1342}
1343
1344static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1345{
1346        unsigned int section;
1347
1348        for (section = 0; section < sect_attrs->nsections; section++)
1349                kfree(sect_attrs->attrs[section].name);
1350        kfree(sect_attrs);
1351}
1352
1353static void add_sect_attrs(struct module *mod, const struct load_info *info)
1354{
1355        unsigned int nloaded = 0, i, size[2];
1356        struct module_sect_attrs *sect_attrs;
1357        struct module_sect_attr *sattr;
1358        struct attribute **gattr;
1359
1360        /* Count loaded sections and allocate structures */
1361        for (i = 0; i < info->hdr->e_shnum; i++)
1362                if (!sect_empty(&info->sechdrs[i]))
1363                        nloaded++;
1364        size[0] = ALIGN(sizeof(*sect_attrs)
1365                        + nloaded * sizeof(sect_attrs->attrs[0]),
1366                        sizeof(sect_attrs->grp.attrs[0]));
1367        size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1368        sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1369        if (sect_attrs == NULL)
1370                return;
1371
1372        /* Setup section attributes. */
1373        sect_attrs->grp.name = "sections";
1374        sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1375
1376        sect_attrs->nsections = 0;
1377        sattr = &sect_attrs->attrs[0];
1378        gattr = &sect_attrs->grp.attrs[0];
1379        for (i = 0; i < info->hdr->e_shnum; i++) {
1380                Elf_Shdr *sec = &info->sechdrs[i];
1381                if (sect_empty(sec))
1382                        continue;
1383                sattr->address = sec->sh_addr;
1384                sattr->name = kstrdup(info->secstrings + sec->sh_name,
1385                                        GFP_KERNEL);
1386                if (sattr->name == NULL)
1387                        goto out;
1388                sect_attrs->nsections++;
1389                sysfs_attr_init(&sattr->mattr.attr);
1390                sattr->mattr.show = module_sect_show;
1391                sattr->mattr.store = NULL;
1392                sattr->mattr.attr.name = sattr->name;
1393                sattr->mattr.attr.mode = S_IRUGO;
1394                *(gattr++) = &(sattr++)->mattr.attr;
1395        }
1396        *gattr = NULL;
1397
1398        if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1399                goto out;
1400
1401        mod->sect_attrs = sect_attrs;
1402        return;
1403  out:
1404        free_sect_attrs(sect_attrs);
1405}
1406
1407static void remove_sect_attrs(struct module *mod)
1408{
1409        if (mod->sect_attrs) {
1410                sysfs_remove_group(&mod->mkobj.kobj,
1411                                   &mod->sect_attrs->grp);
1412                /* We are positive that no one is using any sect attrs
1413                 * at this point.  Deallocate immediately. */
1414                free_sect_attrs(mod->sect_attrs);
1415                mod->sect_attrs = NULL;
1416        }
1417}
1418
1419/*
1420 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1421 */
1422
1423struct module_notes_attrs {
1424        struct kobject *dir;
1425        unsigned int notes;
1426        struct bin_attribute attrs[0];
1427};
1428
1429static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1430                                 struct bin_attribute *bin_attr,
1431                                 char *buf, loff_t pos, size_t count)
1432{
1433        /*
1434         * The caller checked the pos and count against our size.
1435         */
1436        memcpy(buf, bin_attr->private + pos, count);
1437        return count;
1438}
1439
1440static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1441                             unsigned int i)
1442{
1443        if (notes_attrs->dir) {
1444                while (i-- > 0)
1445                        sysfs_remove_bin_file(notes_attrs->dir,
1446                                              &notes_attrs->attrs[i]);
1447                kobject_put(notes_attrs->dir);
1448        }
1449        kfree(notes_attrs);
1450}
1451
1452static void add_notes_attrs(struct module *mod, const struct load_info *info)
1453{
1454        unsigned int notes, loaded, i;
1455        struct module_notes_attrs *notes_attrs;
1456        struct bin_attribute *nattr;
1457
1458        /* failed to create section attributes, so can't create notes */
1459        if (!mod->sect_attrs)
1460                return;
1461
1462        /* Count notes sections and allocate structures.  */
1463        notes = 0;
1464        for (i = 0; i < info->hdr->e_shnum; i++)
1465                if (!sect_empty(&info->sechdrs[i]) &&
1466                    (info->sechdrs[i].sh_type == SHT_NOTE))
1467                        ++notes;
1468
1469        if (notes == 0)
1470                return;
1471
1472        notes_attrs = kzalloc(sizeof(*notes_attrs)
1473                              + notes * sizeof(notes_attrs->attrs[0]),
1474                              GFP_KERNEL);
1475        if (notes_attrs == NULL)
1476                return;
1477
1478        notes_attrs->notes = notes;
1479        nattr = &notes_attrs->attrs[0];
1480        for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1481                if (sect_empty(&info->sechdrs[i]))
1482                        continue;
1483                if (info->sechdrs[i].sh_type == SHT_NOTE) {
1484                        sysfs_bin_attr_init(nattr);
1485                        nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1486                        nattr->attr.mode = S_IRUGO;
1487                        nattr->size = info->sechdrs[i].sh_size;
1488                        nattr->private = (void *) info->sechdrs[i].sh_addr;
1489                        nattr->read = module_notes_read;
1490                        ++nattr;
1491                }
1492                ++loaded;
1493        }
1494
1495        notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1496        if (!notes_attrs->dir)
1497                goto out;
1498
1499        for (i = 0; i < notes; ++i)
1500                if (sysfs_create_bin_file(notes_attrs->dir,
1501                                          &notes_attrs->attrs[i]))
1502                        goto out;
1503
1504        mod->notes_attrs = notes_attrs;
1505        return;
1506
1507  out:
1508        free_notes_attrs(notes_attrs, i);
1509}
1510
1511static void remove_notes_attrs(struct module *mod)
1512{
1513        if (mod->notes_attrs)
1514                free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1515}
1516
1517#else
1518
1519static inline void add_sect_attrs(struct module *mod,
1520                                  const struct load_info *info)
1521{
1522}
1523
1524static inline void remove_sect_attrs(struct module *mod)
1525{
1526}
1527
1528static inline void add_notes_attrs(struct module *mod,
1529                                   const struct load_info *info)
1530{
1531}
1532
1533static inline void remove_notes_attrs(struct module *mod)
1534{
1535}
1536#endif /* CONFIG_KALLSYMS */
1537
1538static void add_usage_links(struct module *mod)
1539{
1540#ifdef CONFIG_MODULE_UNLOAD
1541        struct module_use *use;
1542        int nowarn;
1543
1544        mutex_lock(&module_mutex);
1545        list_for_each_entry(use, &mod->target_list, target_list) {
1546                nowarn = sysfs_create_link(use->target->holders_dir,
1547                                           &mod->mkobj.kobj, mod->name);
1548        }
1549        mutex_unlock(&module_mutex);
1550#endif
1551}
1552
1553static void del_usage_links(struct module *mod)
1554{
1555#ifdef CONFIG_MODULE_UNLOAD
1556        struct module_use *use;
1557
1558        mutex_lock(&module_mutex);
1559        list_for_each_entry(use, &mod->target_list, target_list)
1560                sysfs_remove_link(use->target->holders_dir, mod->name);
1561        mutex_unlock(&module_mutex);
1562#endif
1563}
1564
1565static int module_add_modinfo_attrs(struct module *mod)
1566{
1567        struct module_attribute *attr;
1568        struct module_attribute *temp_attr;
1569        int error = 0;
1570        int i;
1571
1572        mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1573                                        (ARRAY_SIZE(modinfo_attrs) + 1)),
1574                                        GFP_KERNEL);
1575        if (!mod->modinfo_attrs)
1576                return -ENOMEM;
1577
1578        temp_attr = mod->modinfo_attrs;
1579        for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1580                if (!attr->test ||
1581                    (attr->test && attr->test(mod))) {
1582                        memcpy(temp_attr, attr, sizeof(*temp_attr));
1583                        sysfs_attr_init(&temp_attr->attr);
1584                        error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1585                        ++temp_attr;
1586                }
1587        }
1588        return error;
1589}
1590
1591static void module_remove_modinfo_attrs(struct module *mod)
1592{
1593        struct module_attribute *attr;
1594        int i;
1595
1596        for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1597                /* pick a field to test for end of list */
1598                if (!attr->attr.name)
1599                        break;
1600                sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1601                if (attr->free)
1602                        attr->free(mod);
1603        }
1604        kfree(mod->modinfo_attrs);
1605}
1606
1607static int mod_sysfs_init(struct module *mod)
1608{
1609        int err;
1610        struct kobject *kobj;
1611
1612        if (!module_sysfs_initialized) {
1613                printk(KERN_ERR "%s: module sysfs not initialized\n",
1614                       mod->name);
1615                err = -EINVAL;
1616                goto out;
1617        }
1618
1619        kobj = kset_find_obj(module_kset, mod->name);
1620        if (kobj) {
1621                printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1622                kobject_put(kobj);
1623                err = -EINVAL;
1624                goto out;
1625        }
1626
1627        mod->mkobj.mod = mod;
1628
1629        memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1630        mod->mkobj.kobj.kset = module_kset;
1631        err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1632                                   "%s", mod->name);
1633        if (err)
1634                kobject_put(&mod->mkobj.kobj);
1635
1636        /* delay uevent until full sysfs population */
1637out:
1638        return err;
1639}
1640
1641static int mod_sysfs_setup(struct module *mod,
1642                           const struct load_info *info,
1643                           struct kernel_param *kparam,
1644                           unsigned int num_params)
1645{
1646        int err;
1647
1648        err = mod_sysfs_init(mod);
1649        if (err)
1650                goto out;
1651
1652        mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1653        if (!mod->holders_dir) {
1654                err = -ENOMEM;
1655                goto out_unreg;
1656        }
1657
1658        err = module_param_sysfs_setup(mod, kparam, num_params);
1659        if (err)
1660                goto out_unreg_holders;
1661
1662        err = module_add_modinfo_attrs(mod);
1663        if (err)
1664                goto out_unreg_param;
1665
1666        add_usage_links(mod);
1667        add_sect_attrs(mod, info);
1668        add_notes_attrs(mod, info);
1669
1670        kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1671        return 0;
1672
1673out_unreg_param:
1674        module_param_sysfs_remove(mod);
1675out_unreg_holders:
1676        kobject_put(mod->holders_dir);
1677out_unreg:
1678        kobject_put(&mod->mkobj.kobj);
1679out:
1680        return err;
1681}
1682
1683static void mod_sysfs_fini(struct module *mod)
1684{
1685        remove_notes_attrs(mod);
1686        remove_sect_attrs(mod);
1687        kobject_put(&mod->mkobj.kobj);
1688}
1689
1690#else /* !CONFIG_SYSFS */
1691
1692static int mod_sysfs_setup(struct module *mod,
1693                           const struct load_info *info,
1694                           struct kernel_param *kparam,
1695                           unsigned int num_params)
1696{
1697        return 0;
1698}
1699
1700static void mod_sysfs_fini(struct module *mod)
1701{
1702}
1703
1704static void module_remove_modinfo_attrs(struct module *mod)
1705{
1706}
1707
1708static void del_usage_links(struct module *mod)
1709{
1710}
1711
1712#endif /* CONFIG_SYSFS */
1713
1714static void mod_sysfs_teardown(struct module *mod)
1715{
1716        del_usage_links(mod);
1717        module_remove_modinfo_attrs(mod);
1718        module_param_sysfs_remove(mod);
1719        kobject_put(mod->mkobj.drivers_dir);
1720        kobject_put(mod->holders_dir);
1721        mod_sysfs_fini(mod);
1722}
1723
1724/*
1725 * unlink the module with the whole machine is stopped with interrupts off
1726 * - this defends against kallsyms not taking locks
1727 */
1728static int __unlink_module(void *_mod)
1729{
1730        struct module *mod = _mod;
1731        list_del(&mod->list);
1732        module_bug_cleanup(mod);
1733        return 0;
1734}
1735
1736#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1737/*
1738 * LKM RO/NX protection: protect module's text/ro-data
1739 * from modification and any data from execution.
1740 */
1741void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1742{
1743        unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1744        unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1745
1746        if (end_pfn > begin_pfn)
1747                set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1748}
1749
1750static void set_section_ro_nx(void *base,
1751                        unsigned long text_size,
1752                        unsigned long ro_size,
1753                        unsigned long total_size)
1754{
1755        /* begin and end PFNs of the current subsection */
1756        unsigned long begin_pfn;
1757        unsigned long end_pfn;
1758
1759        /*
1760         * Set RO for module text and RO-data:
1761         * - Always protect first page.
1762         * - Do not protect last partial page.
1763         */
1764        if (ro_size > 0)
1765                set_page_attributes(base, base + ro_size, set_memory_ro);
1766
1767        /*
1768         * Set NX permissions for module data:
1769         * - Do not protect first partial page.
1770         * - Always protect last page.
1771         */
1772        if (total_size > text_size) {
1773                begin_pfn = PFN_UP((unsigned long)base + text_size);
1774                end_pfn = PFN_UP((unsigned long)base + total_size);
1775                if (end_pfn > begin_pfn)
1776                        set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1777        }
1778}
1779
1780static void unset_module_core_ro_nx(struct module *mod)
1781{
1782        set_page_attributes(mod->module_core + mod->core_text_size,
1783                mod->module_core + mod->core_size,
1784                set_memory_x);
1785        set_page_attributes(mod->module_core,
1786                mod->module_core + mod->core_ro_size,
1787                set_memory_rw);
1788}
1789
1790static void unset_module_init_ro_nx(struct module *mod)
1791{
1792        set_page_attributes(mod->module_init + mod->init_text_size,
1793                mod->module_init + mod->init_size,
1794                set_memory_x);
1795        set_page_attributes(mod->module_init,
1796                mod->module_init + mod->init_ro_size,
1797                set_memory_rw);
1798}
1799
1800/* Iterate through all modules and set each module's text as RW */
1801void set_all_modules_text_rw(void)
1802{
1803        struct module *mod;
1804
1805        mutex_lock(&module_mutex);
1806        list_for_each_entry_rcu(mod, &modules, list) {
1807                if (mod->state == MODULE_STATE_UNFORMED)
1808                        continue;
1809                if ((mod->module_core) && (mod->core_text_size)) {
1810                        set_page_attributes(mod->module_core,
1811                                                mod->module_core + mod->core_text_size,
1812                                                set_memory_rw);
1813                }
1814                if ((mod->module_init) && (mod->init_text_size)) {
1815                        set_page_attributes(mod->module_init,
1816                                                mod->module_init + mod->init_text_size,
1817                                                set_memory_rw);
1818                }
1819        }
1820        mutex_unlock(&module_mutex);
1821}
1822
1823/* Iterate through all modules and set each module's text as RO */
1824void set_all_modules_text_ro(void)
1825{
1826        struct module *mod;
1827
1828        mutex_lock(&module_mutex);
1829        list_for_each_entry_rcu(mod, &modules, list) {
1830                if (mod->state == MODULE_STATE_UNFORMED)
1831                        continue;
1832                if ((mod->module_core) && (mod->core_text_size)) {
1833                        set_page_attributes(mod->module_core,
1834                                                mod->module_core + mod->core_text_size,
1835                                                set_memory_ro);
1836                }
1837                if ((mod->module_init) && (mod->init_text_size)) {
1838                        set_page_attributes(mod->module_init,
1839                                                mod->module_init + mod->init_text_size,
1840                                                set_memory_ro);
1841                }
1842        }
1843        mutex_unlock(&module_mutex);
1844}
1845#else
1846static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1847static void unset_module_core_ro_nx(struct module *mod) { }
1848static void unset_module_init_ro_nx(struct module *mod) { }
1849#endif
1850
1851void __weak module_free(struct module *mod, void *module_region)
1852{
1853        vfree(module_region);
1854}
1855
1856void __weak module_arch_cleanup(struct module *mod)
1857{
1858}
1859
1860/* Free a module, remove from lists, etc. */
1861static void free_module(struct module *mod)
1862{
1863        trace_module_free(mod);
1864
1865        mod_sysfs_teardown(mod);
1866
1867        /* We leave it in list to prevent duplicate loads, but make sure
1868         * that noone uses it while it's being deconstructed. */
1869        mod->state = MODULE_STATE_UNFORMED;
1870
1871        /* Remove dynamic debug info */
1872        ddebug_remove_module(mod->name);
1873
1874        /* Arch-specific cleanup. */
1875        module_arch_cleanup(mod);
1876
1877        /* Module unload stuff */
1878        module_unload_free(mod);
1879
1880        /* Free any allocated parameters. */
1881        destroy_params(mod->kp, mod->num_kp);
1882
1883        /* Now we can delete it from the lists */
1884        mutex_lock(&module_mutex);
1885        stop_machine(__unlink_module, mod, NULL);
1886        mutex_unlock(&module_mutex);
1887
1888        /* This may be NULL, but that's OK */
1889        unset_module_init_ro_nx(mod);
1890        module_free(mod, mod->module_init);
1891        kfree(mod->args);
1892        percpu_modfree(mod);
1893
1894        /* Free lock-classes: */
1895        lockdep_free_key_range(mod->module_core, mod->core_size);
1896
1897        /* Finally, free the core (containing the module structure) */
1898        unset_module_core_ro_nx(mod);
1899        module_free(mod, mod->module_core);
1900
1901#ifdef CONFIG_MPU
1902        update_protections(current->mm);
1903#endif
1904}
1905
1906void *__symbol_get(const char *symbol)
1907{
1908        struct module *owner;
1909        const struct kernel_symbol *sym;
1910
1911        preempt_disable();
1912        sym = find_symbol(symbol, &owner, NULL, true, true);
1913        if (sym && strong_try_module_get(owner))
1914                sym = NULL;
1915        preempt_enable();
1916
1917        return sym ? (void *)sym->value : NULL;
1918}
1919EXPORT_SYMBOL_GPL(__symbol_get);
1920
1921/*
1922 * Ensure that an exported symbol [global namespace] does not already exist
1923 * in the kernel or in some other module's exported symbol table.
1924 *
1925 * You must hold the module_mutex.
1926 */
1927static int verify_export_symbols(struct module *mod)
1928{
1929        unsigned int i;
1930        struct module *owner;
1931        const struct kernel_symbol *s;
1932        struct {
1933                const struct kernel_symbol *sym;
1934                unsigned int num;
1935        } arr[] = {
1936                { mod->syms, mod->num_syms },
1937                { mod->gpl_syms, mod->num_gpl_syms },
1938                { mod->gpl_future_syms, mod->num_gpl_future_syms },
1939#ifdef CONFIG_UNUSED_SYMBOLS
1940                { mod->unused_syms, mod->num_unused_syms },
1941                { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1942#endif
1943        };
1944
1945        for (i = 0; i < ARRAY_SIZE(arr); i++) {
1946                for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1947                        if (find_symbol(s->name, &owner, NULL, true, false)) {
1948                                printk(KERN_ERR
1949                                       "%s: exports duplicate symbol %s"
1950                                       " (owned by %s)\n",
1951                                       mod->name, s->name, module_name(owner));
1952                                return -ENOEXEC;
1953                        }
1954                }
1955        }
1956        return 0;
1957}
1958
1959/* Change all symbols so that st_value encodes the pointer directly. */
1960static int simplify_symbols(struct module *mod, const struct load_info *info)
1961{
1962        Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1963        Elf_Sym *sym = (void *)symsec->sh_addr;
1964        unsigned long secbase;
1965        unsigned int i;
1966        int ret = 0;
1967        const struct kernel_symbol *ksym;
1968
1969        for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1970                const char *name = info->strtab + sym[i].st_name;
1971
1972                switch (sym[i].st_shndx) {
1973                case SHN_COMMON:
1974                        /* We compiled with -fno-common.  These are not
1975                           supposed to happen.  */
1976                        pr_debug("Common symbol: %s\n", name);
1977                        printk("%s: please compile with -fno-common\n",
1978                               mod->name);
1979                        ret = -ENOEXEC;
1980                        break;
1981
1982                case SHN_ABS:
1983                        /* Don't need to do anything */
1984                        pr_debug("Absolute symbol: 0x%08lx\n",
1985                               (long)sym[i].st_value);
1986                        break;
1987
1988                case SHN_UNDEF:
1989                        ksym = resolve_symbol_wait(mod, info, name);
1990                        /* Ok if resolved.  */
1991                        if (ksym && !IS_ERR(ksym)) {
1992                                sym[i].st_value = ksym->value;
1993                                break;
1994                        }
1995
1996                        /* Ok if weak.  */
1997                        if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1998                                break;
1999
2000                        printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
2001                               mod->name, name, PTR_ERR(ksym));
2002                        ret = PTR_ERR(ksym) ?: -ENOENT;
2003                        break;
2004
2005                default:
2006                        /* Divert to percpu allocation if a percpu var. */
2007                        if (sym[i].st_shndx == info->index.pcpu)
2008                                secbase = (unsigned long)mod_percpu(mod);
2009                        else
2010                                secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2011                        sym[i].st_value += secbase;
2012                        break;
2013                }
2014        }
2015
2016        return ret;
2017}
2018
2019static int apply_relocations(struct module *mod, const struct load_info *info)
2020{
2021        unsigned int i;
2022        int err = 0;
2023
2024        /* Now do relocations. */
2025        for (i = 1; i < info->hdr->e_shnum; i++) {
2026                unsigned int infosec = info->sechdrs[i].sh_info;
2027
2028                /* Not a valid relocation section? */
2029                if (infosec >= info->hdr->e_shnum)
2030                        continue;
2031
2032                /* Don't bother with non-allocated sections */
2033                if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2034                        continue;
2035
2036                if (info->sechdrs[i].sh_type == SHT_REL)
2037                        err = apply_relocate(info->sechdrs, info->strtab,
2038                                             info->index.sym, i, mod);
2039                else if (info->sechdrs[i].sh_type == SHT_RELA)
2040                        err = apply_relocate_add(info->sechdrs, info->strtab,
2041                                                 info->index.sym, i, mod);
2042                if (err < 0)
2043                        break;
2044        }
2045        return err;
2046}
2047
2048/* Additional bytes needed by arch in front of individual sections */
2049unsigned int __weak arch_mod_section_prepend(struct module *mod,
2050                                             unsigned int section)
2051{
2052        /* default implementation just returns zero */
2053        return 0;
2054}
2055
2056/* Update size with this section: return offset. */
2057static long get_offset(struct module *mod, unsigned int *size,
2058                       Elf_Shdr *sechdr, unsigned int section)
2059{
2060        long ret;
2061
2062        *size += arch_mod_section_prepend(mod, section);
2063        ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2064        *size = ret + sechdr->sh_size;
2065        return ret;
2066}
2067
2068/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2069   might -- code, read-only data, read-write data, small data.  Tally
2070   sizes, and place the offsets into sh_entsize fields: high bit means it
2071   belongs in init. */
2072static void layout_sections(struct module *mod, struct load_info *info)
2073{
2074        static unsigned long const masks[][2] = {
2075                /* NOTE: all executable code must be the first section
2076                 * in this array; otherwise modify the text_size
2077                 * finder in the two loops below */
2078                { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2079                { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2080                { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2081                { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2082        };
2083        unsigned int m, i;
2084
2085        for (i = 0; i < info->hdr->e_shnum; i++)
2086                info->sechdrs[i].sh_entsize = ~0UL;
2087
2088        pr_debug("Core section allocation order:\n");
2089        for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2090                for (i = 0; i < info->hdr->e_shnum; ++i) {
2091                        Elf_Shdr *s = &info->sechdrs[i];
2092                        const char *sname = info->secstrings + s->sh_name;
2093
2094                        if ((s->sh_flags & masks[m][0]) != masks[m][0]
2095                            || (s->sh_flags & masks[m][1])
2096                            || s->sh_entsize != ~0UL
2097                            || strstarts(sname, ".init"))
2098                                continue;
2099                        s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2100                        pr_debug("\t%s\n", sname);
2101                }
2102                switch (m) {
2103                case 0: /* executable */
2104                        mod->core_size = debug_align(mod->core_size);
2105                        mod->core_text_size = mod->core_size;
2106                        break;
2107                case 1: /* RO: text and ro-data */
2108                        mod->core_size = debug_align(mod->core_size);
2109                        mod->core_ro_size = mod->core_size;
2110                        break;
2111                case 3: /* whole core */
2112                        mod->core_size = debug_align(mod->core_size);
2113                        break;
2114                }
2115        }
2116
2117        pr_debug("Init section allocation order:\n");
2118        for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2119                for (i = 0; i < info->hdr->e_shnum; ++i) {
2120                        Elf_Shdr *s = &info->sechdrs[i];
2121                        const char *sname = info->secstrings + s->sh_name;
2122
2123                        if ((s->sh_flags & masks[m][0]) != masks[m][0]
2124                            || (s->sh_flags & masks[m][1])
2125                            || s->sh_entsize != ~0UL
2126                            || !strstarts(sname, ".init"))
2127                                continue;
2128                        s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2129                                         | INIT_OFFSET_MASK);
2130                        pr_debug("\t%s\n", sname);
2131                }
2132                switch (m) {
2133                case 0: /* executable */
2134                        mod->init_size = debug_align(mod->init_size);
2135                        mod->init_text_size = mod->init_size;
2136                        break;
2137                case 1: /* RO: text and ro-data */
2138                        mod->init_size = debug_align(mod->init_size);
2139                        mod->init_ro_size = mod->init_size;
2140                        break;
2141                case 3: /* whole init */
2142                        mod->init_size = debug_align(mod->init_size);
2143                        break;
2144                }
2145        }
2146}
2147
2148static void set_license(struct module *mod, const char *license)
2149{
2150        if (!license)
2151                license = "unspecified";
2152
2153        if (!license_is_gpl_compatible(license)) {
2154                if (!test_taint(TAINT_PROPRIETARY_MODULE))
2155                        printk(KERN_WARNING "%s: module license '%s' taints "
2156                                "kernel.\n", mod->name, license);
2157                add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2158                                 LOCKDEP_NOW_UNRELIABLE);
2159        }
2160}
2161
2162/* Parse tag=value strings from .modinfo section */
2163static char *next_string(char *string, unsigned long *secsize)
2164{
2165        /* Skip non-zero chars */
2166        while (string[0]) {
2167                string++;
2168                if ((*secsize)-- <= 1)
2169                        return NULL;
2170        }
2171
2172        /* Skip any zero padding. */
2173        while (!string[0]) {
2174                string++;
2175                if ((*secsize)-- <= 1)
2176                        return NULL;
2177        }
2178        return string;
2179}
2180
2181static char *get_modinfo(struct load_info *info, const char *tag)
2182{
2183        char *p;
2184        unsigned int taglen = strlen(tag);
2185        Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2186        unsigned long size = infosec->sh_size;
2187
2188        for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2189                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2190                        return p + taglen + 1;
2191        }
2192        return NULL;
2193}
2194
2195static void setup_modinfo(struct module *mod, struct load_info *info)
2196{
2197        struct module_attribute *attr;
2198        int i;
2199
2200        for (i = 0; (attr = modinfo_attrs[i]); i++) {
2201                if (attr->setup)
2202                        attr->setup(mod, get_modinfo(info, attr->attr.name));
2203        }
2204}
2205
2206static void free_modinfo(struct module *mod)
2207{
2208        struct module_attribute *attr;
2209        int i;
2210
2211        for (i = 0; (attr = modinfo_attrs[i]); i++) {
2212                if (attr->free)
2213                        attr->free(mod);
2214        }
2215}
2216
2217#ifdef CONFIG_KALLSYMS
2218
2219/* lookup symbol in given range of kernel_symbols */
2220static const struct kernel_symbol *lookup_symbol(const char *name,
2221        const struct kernel_symbol *start,
2222        const struct kernel_symbol *stop)
2223{
2224        return bsearch(name, start, stop - start,
2225                        sizeof(struct kernel_symbol), cmp_name);
2226}
2227
2228static int is_exported(const char *name, unsigned long value,
2229                       const struct module *mod)
2230{
2231        const struct kernel_symbol *ks;
2232        if (!mod)
2233                ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2234        else
2235                ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2236        return ks != NULL && ks->value == value;
2237}
2238
2239/* As per nm */
2240static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2241{
2242        const Elf_Shdr *sechdrs = info->sechdrs;
2243
2244        if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2245                if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2246                        return 'v';
2247                else
2248                        return 'w';
2249        }
2250        if (sym->st_shndx == SHN_UNDEF)
2251                return 'U';
2252        if (sym->st_shndx == SHN_ABS)
2253                return 'a';
2254        if (sym->st_shndx >= SHN_LORESERVE)
2255                return '?';
2256        if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2257                return 't';
2258        if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2259            && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2260                if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2261                        return 'r';
2262                else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2263                        return 'g';
2264                else
2265                        return 'd';
2266        }
2267        if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2268                if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2269                        return 's';
2270                else
2271                        return 'b';
2272        }
2273        if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2274                      ".debug")) {
2275                return 'n';
2276        }
2277        return '?';
2278}
2279
2280static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2281                           unsigned int shnum)
2282{
2283        const Elf_Shdr *sec;
2284
2285        if (src->st_shndx == SHN_UNDEF
2286            || src->st_shndx >= shnum
2287            || !src->st_name)
2288                return false;
2289
2290        sec = sechdrs + src->st_shndx;
2291        if (!(sec->sh_flags & SHF_ALLOC)
2292#ifndef CONFIG_KALLSYMS_ALL
2293            || !(sec->sh_flags & SHF_EXECINSTR)
2294#endif
2295            || (sec->sh_entsize & INIT_OFFSET_MASK))
2296                return false;
2297
2298        return true;
2299}
2300
2301/*
2302 * We only allocate and copy the strings needed by the parts of symtab
2303 * we keep.  This is simple, but has the effect of making multiple
2304 * copies of duplicates.  We could be more sophisticated, see
2305 * linux-kernel thread starting with
2306 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2307 */
2308static void layout_symtab(struct module *mod, struct load_info *info)
2309{
2310        Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2311        Elf_Shdr *strsect = info->sechdrs + info->index.str;
2312        const Elf_Sym *src;
2313        unsigned int i, nsrc, ndst, strtab_size = 0;
2314
2315        /* Put symbol section at end of init part of module. */
2316        symsect->sh_flags |= SHF_ALLOC;
2317        symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2318                                         info->index.sym) | INIT_OFFSET_MASK;
2319        pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2320
2321        src = (void *)info->hdr + symsect->sh_offset;
2322        nsrc = symsect->sh_size / sizeof(*src);
2323
2324        /* Compute total space required for the core symbols' strtab. */
2325        for (ndst = i = 0; i < nsrc; i++) {
2326                if (i == 0 ||
2327                    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2328                        strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2329                        ndst++;
2330                }
2331        }
2332
2333        /* Append room for core symbols at end of core part. */
2334        info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2335        info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2336        mod->core_size += strtab_size;
2337
2338        /* Put string table section at end of init part of module. */
2339        strsect->sh_flags |= SHF_ALLOC;
2340        strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2341                                         info->index.str) | INIT_OFFSET_MASK;
2342        pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2343}
2344
2345static void add_kallsyms(struct module *mod, const struct load_info *info)
2346{
2347        unsigned int i, ndst;
2348        const Elf_Sym *src;
2349        Elf_Sym *dst;
2350        char *s;
2351        Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2352
2353        mod->symtab = (void *)symsec->sh_addr;
2354        mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2355        /* Make sure we get permanent strtab: don't use info->strtab. */
2356        mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2357
2358        /* Set types up while we still have access to sections. */
2359        for (i = 0; i < mod->num_symtab; i++)
2360                mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2361
2362        mod->core_symtab = dst = mod->module_core + info->symoffs;
2363        mod->core_strtab = s = mod->module_core + info->stroffs;
2364        src = mod->symtab;
2365        for (ndst = i = 0; i < mod->num_symtab; i++) {
2366                if (i == 0 ||
2367                    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2368                        dst[ndst] = src[i];
2369                        dst[ndst++].st_name = s - mod->core_strtab;
2370                        s += strlcpy(s, &mod->strtab[src[i].st_name],
2371                                     KSYM_NAME_LEN) + 1;
2372                }
2373        }
2374        mod->core_num_syms = ndst;
2375}
2376#else
2377static inline void layout_symtab(struct module *mod, struct load_info *info)
2378{
2379}
2380
2381static void add_kallsyms(struct module *mod, const struct load_info *info)
2382{
2383}
2384#endif /* CONFIG_KALLSYMS */
2385
2386static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2387{
2388        if (!debug)
2389                return;
2390#ifdef CONFIG_DYNAMIC_DEBUG
2391        if (ddebug_add_module(debug, num, debug->modname))
2392                printk(KERN_ERR "dynamic debug error adding module: %s\n",
2393                                        debug->modname);
2394#endif
2395}
2396
2397static void dynamic_debug_remove(struct _ddebug *debug)
2398{
2399        if (debug)
2400                ddebug_remove_module(debug->modname);
2401}
2402
2403void * __weak module_alloc(unsigned long size)
2404{
2405        return vmalloc_exec(size);
2406}
2407
2408static void *module_alloc_update_bounds(unsigned long size)
2409{
2410        void *ret = module_alloc(size);
2411
2412        if (ret) {
2413                mutex_lock(&module_mutex);
2414                /* Update module bounds. */
2415                if ((unsigned long)ret < module_addr_min)
2416                        module_addr_min = (unsigned long)ret;
2417                if ((unsigned long)ret + size > module_addr_max)
2418                        module_addr_max = (unsigned long)ret + size;
2419                mutex_unlock(&module_mutex);
2420        }
2421        return ret;
2422}
2423
2424#ifdef CONFIG_DEBUG_KMEMLEAK
2425static void kmemleak_load_module(const struct module *mod,
2426                                 const struct load_info *info)
2427{
2428        unsigned int i;
2429
2430        /* only scan the sections containing data */
2431        kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2432
2433        for (i = 1; i < info->hdr->e_shnum; i++) {
2434                /* Scan all writable sections that's not executable */
2435                if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2436                    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2437                    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2438                        continue;
2439
2440                kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2441                                   info->sechdrs[i].sh_size, GFP_KERNEL);
2442        }
2443}
2444#else
2445static inline void kmemleak_load_module(const struct module *mod,
2446                                        const struct load_info *info)
2447{
2448}
2449#endif
2450
2451#ifdef CONFIG_MODULE_SIG
2452static int module_sig_check(struct load_info *info)
2453{
2454        int err = -ENOKEY;
2455        const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2456        const void *mod = info->hdr;
2457
2458        if (info->len > markerlen &&
2459            memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2460                /* We truncate the module to discard the signature */
2461                info->len -= markerlen;
2462                err = mod_verify_sig(mod, &info->len);
2463        }
2464
2465        if (!err) {
2466                info->sig_ok = true;
2467                return 0;
2468        }
2469
2470        /* Not having a signature is only an error if we're strict. */
2471        if (err < 0 && fips_enabled)
2472                panic("Module verification failed with error %d in FIPS mode\n",
2473                      err);
2474        if (err == -ENOKEY && !sig_enforce)
2475                err = 0;
2476
2477        return err;
2478}
2479#else /* !CONFIG_MODULE_SIG */
2480static int module_sig_check(struct load_info *info)
2481{
2482        return 0;
2483}
2484#endif /* !CONFIG_MODULE_SIG */
2485
2486/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2487static int elf_header_check(struct load_info *info)
2488{
2489        if (info->len < sizeof(*(info->hdr)))
2490                return -ENOEXEC;
2491
2492        if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2493            || info->hdr->e_type != ET_REL
2494            || !elf_check_arch(info->hdr)
2495            || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2496                return -ENOEXEC;
2497
2498        if (info->hdr->e_shoff >= info->len
2499            || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2500                info->len - info->hdr->e_shoff))
2501                return -ENOEXEC;
2502
2503        return 0;
2504}
2505
2506/* Sets info->hdr and info->len. */
2507static int copy_module_from_user(const void __user *umod, unsigned long len,
2508                                  struct load_info *info)
2509{
2510        int err;
2511
2512        info->len = len;
2513        if (info->len < sizeof(*(info->hdr)))
2514                return -ENOEXEC;
2515
2516        err = security_kernel_module_from_file(NULL);
2517        if (err)
2518                return err;
2519
2520        /* Suck in entire file: we'll want most of it. */
2521        info->hdr = vmalloc(info->len);
2522        if (!info->hdr)
2523                return -ENOMEM;
2524
2525        if (copy_from_user(info->hdr, umod, info->len) != 0) {
2526                vfree(info->hdr);
2527                return -EFAULT;
2528        }
2529
2530        return 0;
2531}
2532
2533/* Sets info->hdr and info->len. */
2534static int copy_module_from_fd(int fd, struct load_info *info)
2535{
2536        struct file *file;
2537        int err;
2538        struct kstat stat;
2539        loff_t pos;
2540        ssize_t bytes = 0;
2541
2542        file = fget(fd);
2543        if (!file)
2544                return -ENOEXEC;
2545
2546        err = security_kernel_module_from_file(file);
2547        if (err)
2548                goto out;
2549
2550        err = vfs_getattr(&file->f_path, &stat);
2551        if (err)
2552                goto out;
2553
2554        if (stat.size > INT_MAX) {
2555                err = -EFBIG;
2556                goto out;
2557        }
2558
2559        /* Don't hand 0 to vmalloc, it whines. */
2560        if (stat.size == 0) {
2561                err = -EINVAL;
2562                goto out;
2563        }
2564
2565        info->hdr = vmalloc(stat.size);
2566        if (!info->hdr) {
2567                err = -ENOMEM;
2568                goto out;
2569        }
2570
2571        pos = 0;
2572        while (pos < stat.size) {
2573                bytes = kernel_read(file, pos, (char *)(info->hdr) + pos,
2574                                    stat.size - pos);
2575                if (bytes < 0) {
2576                        vfree(info->hdr);
2577                        err = bytes;
2578                        goto out;
2579                }
2580                if (bytes == 0)
2581                        break;
2582                pos += bytes;
2583        }
2584        info->len = pos;
2585
2586out:
2587        fput(file);
2588        return err;
2589}
2590
2591static void free_copy(struct load_info *info)
2592{
2593        vfree(info->hdr);
2594}
2595
2596static int rewrite_section_headers(struct load_info *info, int flags)
2597{
2598        unsigned int i;
2599
2600        /* This should always be true, but let's be sure. */
2601        info->sechdrs[0].sh_addr = 0;
2602
2603        for (i = 1; i < info->hdr->e_shnum; i++) {
2604                Elf_Shdr *shdr = &info->sechdrs[i];
2605                if (shdr->sh_type != SHT_NOBITS
2606                    && info->len < shdr->sh_offset + shdr->sh_size) {
2607                        printk(KERN_ERR "Module len %lu truncated\n",
2608                               info->len);
2609                        return -ENOEXEC;
2610                }
2611
2612                /* Mark all sections sh_addr with their address in the
2613                   temporary image. */
2614                shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2615
2616#ifndef CONFIG_MODULE_UNLOAD
2617                /* Don't load .exit sections */
2618                if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2619                        shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2620#endif
2621        }
2622
2623        /* Track but don't keep modinfo and version sections. */
2624        if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2625                info->index.vers = 0; /* Pretend no __versions section! */
2626        else
2627                info->index.vers = find_sec(info, "__versions");
2628        info->index.info = find_sec(info, ".modinfo");
2629        info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2630        info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2631        return 0;
2632}
2633
2634/*
2635 * Set up our basic convenience variables (pointers to section headers,
2636 * search for module section index etc), and do some basic section
2637 * verification.
2638 *
2639 * Return the temporary module pointer (we'll replace it with the final
2640 * one when we move the module sections around).
2641 */
2642static struct module *setup_load_info(struct load_info *info, int flags)
2643{
2644        unsigned int i;
2645        int err;
2646        struct module *mod;
2647
2648        /* Set up the convenience variables */
2649        info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2650        info->secstrings = (void *)info->hdr
2651                + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2652
2653        err = rewrite_section_headers(info, flags);
2654        if (err)
2655                return ERR_PTR(err);
2656
2657        /* Find internal symbols and strings. */
2658        for (i = 1; i < info->hdr->e_shnum; i++) {
2659                if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2660                        info->index.sym = i;
2661                        info->index.str = info->sechdrs[i].sh_link;
2662                        info->strtab = (char *)info->hdr
2663                                + info->sechdrs[info->index.str].sh_offset;
2664                        break;
2665                }
2666        }
2667
2668        info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2669        if (!info->index.mod) {
2670                printk(KERN_WARNING "No module found in object\n");
2671                return ERR_PTR(-ENOEXEC);
2672        }
2673        /* This is temporary: point mod into copy of data. */
2674        mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2675
2676        if (info->index.sym == 0) {
2677                printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2678                       mod->name);
2679                return ERR_PTR(-ENOEXEC);
2680        }
2681
2682        info->index.pcpu = find_pcpusec(info);
2683
2684        /* Check module struct version now, before we try to use module. */
2685        if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2686                return ERR_PTR(-ENOEXEC);
2687
2688        return mod;
2689}
2690
2691static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2692{
2693        const char *modmagic = get_modinfo(info, "vermagic");
2694        int err;
2695
2696        if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2697                modmagic = NULL;
2698
2699        /* This is allowed: modprobe --force will invalidate it. */
2700        if (!modmagic) {
2701                err = try_to_force_load(mod, "bad vermagic");
2702                if (err)
2703                        return err;
2704        } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2705                printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2706                       mod->name, modmagic, vermagic);
2707                return -ENOEXEC;
2708        }
2709
2710        if (!get_modinfo(info, "intree"))
2711                add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2712
2713        if (get_modinfo(info, "staging")) {
2714                add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2715                printk(KERN_WARNING "%s: module is from the staging directory,"
2716                       " the quality is unknown, you have been warned.\n",
2717                       mod->name);
2718        }
2719
2720        /* Set up license info based on the info section */
2721        set_license(mod, get_modinfo(info, "license"));
2722
2723        return 0;
2724}
2725
2726static void find_module_sections(struct module *mod, struct load_info *info)
2727{
2728        mod->kp = section_objs(info, "__param",
2729                               sizeof(*mod->kp), &mod->num_kp);
2730        mod->syms = section_objs(info, "__ksymtab",
2731                                 sizeof(*mod->syms), &mod->num_syms);
2732        mod->crcs = section_addr(info, "__kcrctab");
2733        mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2734                                     sizeof(*mod->gpl_syms),
2735                                     &mod->num_gpl_syms);
2736        mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2737        mod->gpl_future_syms = section_objs(info,
2738                                            "__ksymtab_gpl_future",
2739                                            sizeof(*mod->gpl_future_syms),
2740                                            &mod->num_gpl_future_syms);
2741        mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2742
2743#ifdef CONFIG_UNUSED_SYMBOLS
2744        mod->unused_syms = section_objs(info, "__ksymtab_unused",
2745                                        sizeof(*mod->unused_syms),
2746                                        &mod->num_unused_syms);
2747        mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2748        mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2749                                            sizeof(*mod->unused_gpl_syms),
2750                                            &mod->num_unused_gpl_syms);
2751        mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2752#endif
2753#ifdef CONFIG_CONSTRUCTORS
2754        mod->ctors = section_objs(info, ".ctors",
2755                                  sizeof(*mod->ctors), &mod->num_ctors);
2756#endif
2757
2758#ifdef CONFIG_TRACEPOINTS
2759        mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2760                                             sizeof(*mod->tracepoints_ptrs),
2761                                             &mod->num_tracepoints);
2762#endif
2763#ifdef HAVE_JUMP_LABEL
2764        mod->jump_entries = section_objs(info, "__jump_table",
2765                                        sizeof(*mod->jump_entries),
2766                                        &mod->num_jump_entries);
2767#endif
2768#ifdef CONFIG_EVENT_TRACING
2769        mod->trace_events = section_objs(info, "_ftrace_events",
2770                                         sizeof(*mod->trace_events),
2771                                         &mod->num_trace_events);
2772#endif
2773#ifdef CONFIG_TRACING
2774        mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2775                                         sizeof(*mod->trace_bprintk_fmt_start),
2776                                         &mod->num_trace_bprintk_fmt);
2777#endif
2778#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2779        /* sechdrs[0].sh_size is always zero */
2780        mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2781                                             sizeof(*mod->ftrace_callsites),
2782                                             &mod->num_ftrace_callsites);
2783#endif
2784
2785        mod->extable = section_objs(info, "__ex_table",
2786                                    sizeof(*mod->extable), &mod->num_exentries);
2787
2788        if (section_addr(info, "__obsparm"))
2789                printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2790                       mod->name);
2791
2792        info->debug = section_objs(info, "__verbose",
2793                                   sizeof(*info->debug), &info->num_debug);
2794}
2795
2796static int move_module(struct module *mod, struct load_info *info)
2797{
2798        int i;
2799        void *ptr;
2800
2801        /* Do the allocs. */
2802        ptr = module_alloc_update_bounds(mod->core_size);
2803        /*
2804         * The pointer to this block is stored in the module structure
2805         * which is inside the block. Just mark it as not being a
2806         * leak.
2807         */
2808        kmemleak_not_leak(ptr);
2809        if (!ptr)
2810                return -ENOMEM;
2811
2812        memset(ptr, 0, mod->core_size);
2813        mod->module_core = ptr;
2814
2815        if (mod->init_size) {
2816                ptr = module_alloc_update_bounds(mod->init_size);
2817                /*
2818                 * The pointer to this block is stored in the module structure
2819                 * which is inside the block. This block doesn't need to be
2820                 * scanned as it contains data and code that will be freed
2821                 * after the module is initialized.
2822                 */
2823                kmemleak_ignore(ptr);
2824                if (!ptr) {
2825                        module_free(mod, mod->module_core);
2826                        return -ENOMEM;
2827                }
2828                memset(ptr, 0, mod->init_size);
2829                mod->module_init = ptr;
2830        } else
2831                mod->module_init = NULL;
2832
2833        /* Transfer each section which specifies SHF_ALLOC */
2834        pr_debug("final section addresses:\n");
2835        for (i = 0; i < info->hdr->e_shnum; i++) {
2836                void *dest;
2837                Elf_Shdr *shdr = &info->sechdrs[i];
2838
2839                if (!(shdr->sh_flags & SHF_ALLOC))
2840                        continue;
2841
2842                if (shdr->sh_entsize & INIT_OFFSET_MASK)
2843                        dest = mod->module_init
2844                                + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2845                else
2846                        dest = mod->module_core + shdr->sh_entsize;
2847
2848                if (shdr->sh_type != SHT_NOBITS)
2849                        memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2850                /* Update sh_addr to point to copy in image. */
2851                shdr->sh_addr = (unsigned long)dest;
2852                pr_debug("\t0x%lx %s\n",
2853                         (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2854        }
2855
2856        return 0;
2857}
2858
2859static int check_module_license_and_versions(struct module *mod)
2860{
2861        /*
2862         * ndiswrapper is under GPL by itself, but loads proprietary modules.
2863         * Don't use add_taint_module(), as it would prevent ndiswrapper from
2864         * using GPL-only symbols it needs.
2865         */
2866        if (strcmp(mod->name, "ndiswrapper") == 0)
2867                add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2868
2869        /* driverloader was caught wrongly pretending to be under GPL */
2870        if (strcmp(mod->name, "driverloader") == 0)
2871                add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2872                                 LOCKDEP_NOW_UNRELIABLE);
2873
2874        /* lve claims to be GPL but upstream won't provide source */
2875        if (strcmp(mod->name, "lve") == 0)
2876                add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2877                                 LOCKDEP_NOW_UNRELIABLE);
2878
2879#ifdef CONFIG_MODVERSIONS
2880        if ((mod->num_syms && !mod->crcs)
2881            || (mod->num_gpl_syms && !mod->gpl_crcs)
2882            || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2883#ifdef CONFIG_UNUSED_SYMBOLS
2884            || (mod->num_unused_syms && !mod->unused_crcs)
2885            || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2886#endif
2887                ) {
2888                return try_to_force_load(mod,
2889                                         "no versions for exported symbols");
2890        }
2891#endif
2892        return 0;
2893}
2894
2895static void flush_module_icache(const struct module *mod)
2896{
2897        mm_segment_t old_fs;
2898
2899        /* flush the icache in correct context */
2900        old_fs = get_fs();
2901        set_fs(KERNEL_DS);
2902
2903        /*
2904         * Flush the instruction cache, since we've played with text.
2905         * Do it before processing of module parameters, so the module
2906         * can provide parameter accessor functions of its own.
2907         */
2908        if (mod->module_init)
2909                flush_icache_range((unsigned long)mod->module_init,
2910                                   (unsigned long)mod->module_init
2911                                   + mod->init_size);
2912        flush_icache_range((unsigned long)mod->module_core,
2913                           (unsigned long)mod->module_core + mod->core_size);
2914
2915        set_fs(old_fs);
2916}
2917
2918int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2919                                     Elf_Shdr *sechdrs,
2920                                     char *secstrings,
2921                                     struct module *mod)
2922{
2923        return 0;
2924}
2925
2926static struct module *layout_and_allocate(struct load_info *info, int flags)
2927{
2928        /* Module within temporary copy. */
2929        struct module *mod;
2930        int err;
2931
2932        mod = setup_load_info(info, flags);
2933        if (IS_ERR(mod))
2934                return mod;
2935
2936        err = check_modinfo(mod, info, flags);
2937        if (err)
2938                return ERR_PTR(err);
2939
2940        /* Allow arches to frob section contents and sizes.  */
2941        err = module_frob_arch_sections(info->hdr, info->sechdrs,
2942                                        info->secstrings, mod);
2943        if (err < 0)
2944                return ERR_PTR(err);
2945
2946        /* We will do a special allocation for per-cpu sections later. */
2947        info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2948
2949        /* Determine total sizes, and put offsets in sh_entsize.  For now
2950           this is done generically; there doesn't appear to be any
2951           special cases for the architectures. */
2952        layout_sections(mod, info);
2953        layout_symtab(mod, info);
2954
2955        /* Allocate and move to the final place */
2956        err = move_module(mod, info);
2957        if (err)
2958                return ERR_PTR(err);
2959
2960        /* Module has been copied to its final place now: return it. */
2961        mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2962        kmemleak_load_module(mod, info);
2963        return mod;
2964}
2965
2966static int alloc_module_percpu(struct module *mod, struct load_info *info)
2967{
2968        Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
2969        if (!pcpusec->sh_size)
2970                return 0;
2971
2972        /* We have a special allocation for this section. */
2973        return percpu_modalloc(mod, pcpusec->sh_size, pcpusec->sh_addralign);
2974}
2975
2976/* mod is no longer valid after this! */
2977static void module_deallocate(struct module *mod, struct load_info *info)
2978{
2979        percpu_modfree(mod);
2980        module_free(mod, mod->module_init);
2981        module_free(mod, mod->module_core);
2982}
2983
2984int __weak module_finalize(const Elf_Ehdr *hdr,
2985                           const Elf_Shdr *sechdrs,
2986                           struct module *me)
2987{
2988        return 0;
2989}
2990
2991static int post_relocation(struct module *mod, const struct load_info *info)
2992{
2993        /* Sort exception table now relocations are done. */
2994        sort_extable(mod->extable, mod->extable + mod->num_exentries);
2995
2996        /* Copy relocated percpu area over. */
2997        percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2998                       info->sechdrs[info->index.pcpu].sh_size);
2999
3000        /* Setup kallsyms-specific fields. */
3001        add_kallsyms(mod, info);
3002
3003        /* Arch-specific module finalizing. */
3004        return module_finalize(info->hdr, info->sechdrs, mod);
3005}
3006
3007/* Is this module of this name done loading?  No locks held. */
3008static bool finished_loading(const char *name)
3009{
3010        struct module *mod;
3011        bool ret;
3012
3013        mutex_lock(&module_mutex);
3014        mod = find_module_all(name, true);
3015        ret = !mod || mod->state == MODULE_STATE_LIVE
3016                || mod->state == MODULE_STATE_GOING;
3017        mutex_unlock(&module_mutex);
3018
3019        return ret;
3020}
3021
3022/* Call module constructors. */
3023static void do_mod_ctors(struct module *mod)
3024{
3025#ifdef CONFIG_CONSTRUCTORS
3026        unsigned long i;
3027
3028        for (i = 0; i < mod->num_ctors; i++)
3029                mod->ctors[i]();
3030#endif
3031}
3032
3033/* This is where the real work happens */
3034static int do_init_module(struct module *mod)
3035{
3036        int ret = 0;
3037
3038        /*
3039         * We want to find out whether @mod uses async during init.  Clear
3040         * PF_USED_ASYNC.  async_schedule*() will set it.
3041         */
3042        current->flags &= ~PF_USED_ASYNC;
3043
3044        blocking_notifier_call_chain(&module_notify_list,
3045                        MODULE_STATE_COMING, mod);
3046
3047        /* Set RO and NX regions for core */
3048        set_section_ro_nx(mod->module_core,
3049                                mod->core_text_size,
3050                                mod->core_ro_size,
3051                                mod->core_size);
3052
3053        /* Set RO and NX regions for init */
3054        set_section_ro_nx(mod->module_init,
3055                                mod->init_text_size,
3056                                mod->init_ro_size,
3057                                mod->init_size);
3058
3059        do_mod_ctors(mod);
3060        /* Start the module */
3061        if (mod->init != NULL)
3062                ret = do_one_initcall(mod->init);
3063        if (ret < 0) {
3064                /* Init routine failed: abort.  Try to protect us from
3065                   buggy refcounters. */
3066                mod->state = MODULE_STATE_GOING;
3067                synchronize_sched();
3068                module_put(mod);
3069                blocking_notifier_call_chain(&module_notify_list,
3070                                             MODULE_STATE_GOING, mod);
3071                free_module(mod);
3072                wake_up_all(&module_wq);
3073                return ret;
3074        }
3075        if (ret > 0) {
3076                printk(KERN_WARNING
3077"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
3078"%s: loading module anyway...\n",
3079                       __func__, mod->name, ret,
3080                       __func__);
3081                dump_stack();
3082        }
3083
3084        /* Now it's a first class citizen! */
3085        mod->state = MODULE_STATE_LIVE;
3086        blocking_notifier_call_chain(&module_notify_list,
3087                                     MODULE_STATE_LIVE, mod);
3088
3089        /*
3090         * We need to finish all async code before the module init sequence
3091         * is done.  This has potential to deadlock.  For example, a newly
3092         * detected block device can trigger request_module() of the
3093         * default iosched from async probing task.  Once userland helper
3094         * reaches here, async_synchronize_full() will wait on the async
3095         * task waiting on request_module() and deadlock.
3096         *
3097         * This deadlock is avoided by perfomring async_synchronize_full()
3098         * iff module init queued any async jobs.  This isn't a full
3099         * solution as it will deadlock the same if module loading from
3100         * async jobs nests more than once; however, due to the various
3101         * constraints, this hack seems to be the best option for now.
3102         * Please refer to the following thread for details.
3103         *
3104         * http://thread.gmane.org/gmane.linux.kernel/1420814
3105         */
3106        if (current->flags & PF_USED_ASYNC)
3107                async_synchronize_full();
3108
3109        mutex_lock(&module_mutex);
3110        /* Drop initial reference. */
3111        module_put(mod);
3112        trim_init_extable(mod);
3113#ifdef CONFIG_KALLSYMS
3114        mod->num_symtab = mod->core_num_syms;
3115        mod->symtab = mod->core_symtab;
3116        mod->strtab = mod->core_strtab;
3117#endif
3118        unset_module_init_ro_nx(mod);
3119        module_free(mod, mod->module_init);
3120        mod->module_init = NULL;
3121        mod->init_size = 0;
3122        mod->init_ro_size = 0;
3123        mod->init_text_size = 0;
3124        mutex_unlock(&module_mutex);
3125        wake_up_all(&module_wq);
3126
3127        return 0;
3128}
3129
3130static int may_init_module(void)
3131{
3132        if (!capable(CAP_SYS_MODULE) || modules_disabled)
3133                return -EPERM;
3134
3135        return 0;
3136}
3137
3138/*
3139 * We try to place it in the list now to make sure it's unique before
3140 * we dedicate too many resources.  In particular, temporary percpu
3141 * memory exhaustion.
3142 */
3143static int add_unformed_module(struct module *mod)
3144{
3145        int err;
3146        struct module *old;
3147
3148        mod->state = MODULE_STATE_UNFORMED;
3149
3150again:
3151        mutex_lock(&module_mutex);
3152        if ((old = find_module_all(mod->name, true)) != NULL) {
3153                if (old->state == MODULE_STATE_COMING
3154                    || old->state == MODULE_STATE_UNFORMED) {
3155                        /* Wait in case it fails to load. */
3156                        mutex_unlock(&module_mutex);
3157                        err = wait_event_interruptible(module_wq,
3158                                               finished_loading(mod->name));
3159                        if (err)
3160                                goto out_unlocked;
3161                        goto again;
3162                }
3163                err = -EEXIST;
3164                goto out;
3165        }
3166        list_add_rcu(&mod->list, &modules);
3167        err = 0;
3168
3169out:
3170        mutex_unlock(&module_mutex);
3171out_unlocked:
3172        return err;
3173}
3174
3175static int complete_formation(struct module *mod, struct load_info *info)
3176{
3177        int err;
3178
3179        mutex_lock(&module_mutex);
3180
3181        /* Find duplicate symbols (must be called under lock). */
3182        err = verify_export_symbols(mod);
3183        if (err < 0)
3184                goto out;
3185
3186        /* This relies on module_mutex for list integrity. */
3187        module_bug_finalize(info->hdr, info->sechdrs, mod);
3188
3189        /* Mark state as coming so strong_try_module_get() ignores us,
3190         * but kallsyms etc. can see us. */
3191        mod->state = MODULE_STATE_COMING;
3192
3193out:
3194        mutex_unlock(&module_mutex);
3195        return err;
3196}
3197
3198/* Allocate and load the module: note that size of section 0 is always
3199   zero, and we rely on this for optional sections. */
3200static int load_module(struct load_info *info, const char __user *uargs,
3201                       int flags)
3202{
3203        struct module *mod;
3204        long err;
3205
3206        err = module_sig_check(info);
3207        if (err)
3208                goto free_copy;
3209
3210        err = elf_header_check(info);
3211        if (err)
3212                goto free_copy;
3213
3214        /* Figure out module layout, and allocate all the memory. */
3215        mod = layout_and_allocate(info, flags);
3216        if (IS_ERR(mod)) {
3217                err = PTR_ERR(mod);
3218                goto free_copy;
3219        }
3220
3221        /* Reserve our place in the list. */
3222        err = add_unformed_module(mod);
3223        if (err)
3224                goto free_module;
3225
3226#ifdef CONFIG_MODULE_SIG
3227        mod->sig_ok = info->sig_ok;
3228        if (!mod->sig_ok) {
3229                printk_once(KERN_NOTICE
3230                            "%s: module verification failed: signature and/or"
3231                            " required key missing - tainting kernel\n",
3232                            mod->name);
3233                add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_STILL_OK);
3234        }
3235#endif
3236
3237        /* To avoid stressing percpu allocator, do this once we're unique. */
3238        err = alloc_module_percpu(mod, info);
3239        if (err)
3240                goto unlink_mod;
3241
3242        /* Now module is in final location, initialize linked lists, etc. */
3243        err = module_unload_init(mod);
3244        if (err)
3245                goto unlink_mod;
3246
3247        /* Now we've got everything in the final locations, we can
3248         * find optional sections. */
3249        find_module_sections(mod, info);
3250
3251        err = check_module_license_and_versions(mod);
3252        if (err)
3253                goto free_unload;
3254
3255        /* Set up MODINFO_ATTR fields */
3256        setup_modinfo(mod, info);
3257
3258        /* Fix up syms, so that st_value is a pointer to location. */
3259        err = simplify_symbols(mod, info);
3260        if (err < 0)
3261                goto free_modinfo;
3262
3263        err = apply_relocations(mod, info);
3264        if (err < 0)
3265                goto free_modinfo;
3266
3267        err = post_relocation(mod, info);
3268        if (err < 0)
3269                goto free_modinfo;
3270
3271        flush_module_icache(mod);
3272
3273        /* Now copy in args */
3274        mod->args = strndup_user(uargs, ~0UL >> 1);
3275        if (IS_ERR(mod->args)) {
3276                err = PTR_ERR(mod->args);
3277                goto free_arch_cleanup;
3278        }
3279
3280        dynamic_debug_setup(info->debug, info->num_debug);
3281
3282        /* Finally it's fully formed, ready to start executing. */
3283        err = complete_formation(mod, info);
3284        if (err)
3285                goto ddebug_cleanup;
3286
3287        /* Module is ready to execute: parsing args may do that. */
3288        err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3289                         -32768, 32767, &ddebug_dyndbg_module_param_cb);
3290        if (err < 0)
3291                goto bug_cleanup;
3292
3293        /* Link in to syfs. */
3294        err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3295        if (err < 0)
3296                goto bug_cleanup;
3297
3298        /* Get rid of temporary copy. */
3299        free_copy(info);
3300
3301        /* Done! */
3302        trace_module_load(mod);
3303
3304        return do_init_module(mod);
3305
3306 bug_cleanup:
3307        /* module_bug_cleanup needs module_mutex protection */
3308        mutex_lock(&module_mutex);
3309        module_bug_cleanup(mod);
3310        mutex_unlock(&module_mutex);
3311 ddebug_cleanup:
3312        dynamic_debug_remove(info->debug);
3313        synchronize_sched();
3314        kfree(mod->args);
3315 free_arch_cleanup:
3316        module_arch_cleanup(mod);
3317 free_modinfo:
3318        free_modinfo(mod);
3319 free_unload:
3320        module_unload_free(mod);
3321 unlink_mod:
3322        mutex_lock(&module_mutex);
3323        /* Unlink carefully: kallsyms could be walking list. */
3324        list_del_rcu(&mod->list);
3325        wake_up_all(&module_wq);
3326        mutex_unlock(&module_mutex);
3327 free_module:
3328        module_deallocate(mod, info);
3329 free_copy:
3330        free_copy(info);
3331        return err;
3332}
3333
3334SYSCALL_DEFINE3(init_module, void __user *, umod,
3335                unsigned long, len, const char __user *, uargs)
3336{
3337        int err;
3338        struct load_info info = { };
3339
3340        err = may_init_module();
3341        if (err)
3342                return err;
3343
3344        pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3345               umod, len, uargs);
3346
3347        err = copy_module_from_user(umod, len, &info);
3348        if (err)
3349                return err;
3350
3351        return load_module(&info, uargs, 0);
3352}
3353
3354SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3355{
3356        int err;
3357        struct load_info info = { };
3358
3359        err = may_init_module();
3360        if (err)
3361                return err;
3362
3363        pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3364
3365        if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3366                      |MODULE_INIT_IGNORE_VERMAGIC))
3367                return -EINVAL;
3368
3369        err = copy_module_from_fd(fd, &info);
3370        if (err)
3371                return err;
3372
3373        return load_module(&info, uargs, flags);
3374}
3375
3376static inline int within(unsigned long addr, void *start, unsigned long size)
3377{
3378        return ((void *)addr >= start && (void *)addr < start + size);
3379}
3380
3381#ifdef CONFIG_KALLSYMS
3382/*
3383 * This ignores the intensely annoying "mapping symbols" found
3384 * in ARM ELF files: $a, $t and $d.
3385 */
3386static inline int is_arm_mapping_symbol(const char *str)
3387{
3388        return str[0] == '$' && strchr("atd", str[1])
3389               && (str[2] == '\0' || str[2] == '.');
3390}
3391
3392static const char *get_ksymbol(struct module *mod,
3393                               unsigned long addr,
3394                               unsigned long *size,
3395                               unsigned long *offset)
3396{
3397        unsigned int i, best = 0;
3398        unsigned long nextval;
3399
3400        /* At worse, next value is at end of module */
3401        if (within_module_init(addr, mod))
3402                nextval = (unsigned long)mod->module_init+mod->init_text_size;
3403        else
3404                nextval = (unsigned long)mod->module_core+mod->core_text_size;
3405
3406        /* Scan for closest preceding symbol, and next symbol. (ELF
3407           starts real symbols at 1). */
3408        for (i = 1; i < mod->num_symtab; i++) {
3409                if (mod->symtab[i].st_shndx == SHN_UNDEF)
3410                        continue;
3411
3412                /* We ignore unnamed symbols: they're uninformative
3413                 * and inserted at a whim. */
3414                if (mod->symtab[i].st_value <= addr
3415                    && mod->symtab[i].st_value > mod->symtab[best].st_value
3416                    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3417                    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3418                        best = i;
3419                if (mod->symtab[i].st_value > addr
3420                    && mod->symtab[i].st_value < nextval
3421                    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3422                    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3423                        nextval = mod->symtab[i].st_value;
3424        }
3425
3426        if (!best)
3427                return NULL;
3428
3429        if (size)
3430                *size = nextval - mod->symtab[best].st_value;
3431        if (offset)
3432                *offset = addr - mod->symtab[best].st_value;
3433        return mod->strtab + mod->symtab[best].st_name;
3434}
3435
3436/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3437 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3438const char *module_address_lookup(unsigned long addr,
3439                            unsigned long *size,
3440                            unsigned long *offset,
3441                            char **modname,
3442                            char *namebuf)
3443{
3444        struct module *mod;
3445        const char *ret = NULL;
3446
3447        preempt_disable();
3448        list_for_each_entry_rcu(mod, &modules, list) {
3449                if (mod->state == MODULE_STATE_UNFORMED)
3450                        continue;
3451                if (within_module_init(addr, mod) ||
3452                    within_module_core(addr, mod)) {
3453                        if (modname)
3454                                *modname = mod->name;
3455                        ret = get_ksymbol(mod, addr, size, offset);
3456                        break;
3457                }
3458        }
3459        /* Make a copy in here where it's safe */
3460        if (ret) {
3461                strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3462                ret = namebuf;
3463        }
3464        preempt_enable();
3465        return ret;
3466}
3467
3468int lookup_module_symbol_name(unsigned long addr, char *symname)
3469{
3470        struct module *mod;
3471
3472        preempt_disable();
3473        list_for_each_entry_rcu(mod, &modules, list) {
3474                if (mod->state == MODULE_STATE_UNFORMED)
3475                        continue;
3476                if (within_module_init(addr, mod) ||
3477                    within_module_core(addr, mod)) {
3478                        const char *sym;
3479
3480                        sym = get_ksymbol(mod, addr, NULL, NULL);
3481                        if (!sym)
3482                                goto out;
3483                        strlcpy(symname, sym, KSYM_NAME_LEN);
3484                        preempt_enable();
3485                        return 0;
3486                }
3487        }
3488out:
3489        preempt_enable();
3490        return -ERANGE;
3491}
3492
3493int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3494                        unsigned long *offset, char *modname, char *name)
3495{
3496        struct module *mod;
3497
3498        preempt_disable();
3499        list_for_each_entry_rcu(mod, &modules, list) {
3500                if (mod->state == MODULE_STATE_UNFORMED)
3501                        continue;
3502                if (within_module_init(addr, mod) ||
3503                    within_module_core(addr, mod)) {
3504                        const char *sym;
3505
3506                        sym = get_ksymbol(mod, addr, size, offset);
3507                        if (!sym)
3508                                goto out;
3509                        if (modname)
3510                                strlcpy(modname, mod->name, MODULE_NAME_LEN);
3511                        if (name)
3512                                strlcpy(name, sym, KSYM_NAME_LEN);
3513                        preempt_enable();
3514                        return 0;
3515                }
3516        }
3517out:
3518        preempt_enable();
3519        return -ERANGE;
3520}
3521
3522int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3523                        char *name, char *module_name, int *exported)
3524{
3525        struct module *mod;
3526
3527        preempt_disable();
3528        list_for_each_entry_rcu(mod, &modules, list) {
3529                if (mod->state == MODULE_STATE_UNFORMED)
3530                        continue;
3531                if (symnum < mod->num_symtab) {
3532                        *value = mod->symtab[symnum].st_value;
3533                        *type = mod->symtab[symnum].st_info;
3534                        strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3535                                KSYM_NAME_LEN);
3536                        strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3537                        *exported = is_exported(name, *value, mod);
3538                        preempt_enable();
3539                        return 0;
3540                }
3541                symnum -= mod->num_symtab;
3542        }
3543        preempt_enable();
3544        return -ERANGE;
3545}
3546
3547static unsigned long mod_find_symname(struct module *mod, const char *name)
3548{
3549        unsigned int i;
3550
3551        for (i = 0; i < mod->num_symtab; i++)
3552                if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3553                    mod->symtab[i].st_info != 'U')
3554                        return mod->symtab[i].st_value;
3555        return 0;
3556}
3557
3558/* Look for this name: can be of form module:name. */
3559unsigned long module_kallsyms_lookup_name(const char *name)
3560{
3561        struct module *mod;
3562        char *colon;
3563        unsigned long ret = 0;
3564
3565        /* Don't lock: we're in enough trouble already. */
3566        preempt_disable();
3567        if ((colon = strchr(name, ':')) != NULL) {
3568                *colon = '\0';
3569                if ((mod = find_module(name)) != NULL)
3570                        ret = mod_find_symname(mod, colon+1);
3571                *colon = ':';
3572        } else {
3573                list_for_each_entry_rcu(mod, &modules, list) {
3574                        if (mod->state == MODULE_STATE_UNFORMED)
3575                                continue;
3576                        if ((ret = mod_find_symname(mod, name)) != 0)
3577                                break;
3578                }
3579        }
3580        preempt_enable();
3581        return ret;
3582}
3583
3584int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3585                                             struct module *, unsigned long),
3586                                   void *data)
3587{
3588        struct module *mod;
3589        unsigned int i;
3590        int ret;
3591
3592        list_for_each_entry(mod, &modules, list) {
3593                if (mod->state == MODULE_STATE_UNFORMED)
3594                        continue;
3595                for (i = 0; i < mod->num_symtab; i++) {
3596                        ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3597                                 mod, mod->symtab[i].st_value);
3598                        if (ret != 0)
3599                                return ret;
3600                }
3601        }
3602        return 0;
3603}
3604#endif /* CONFIG_KALLSYMS */
3605
3606static char *module_flags(struct module *mod, char *buf)
3607{
3608        int bx = 0;
3609
3610        BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3611        if (mod->taints ||
3612            mod->state == MODULE_STATE_GOING ||
3613            mod->state == MODULE_STATE_COMING) {
3614                buf[bx++] = '(';
3615                bx += module_flags_taint(mod, buf + bx);
3616                /* Show a - for module-is-being-unloaded */
3617                if (mod->state == MODULE_STATE_GOING)
3618                        buf[bx++] = '-';
3619                /* Show a + for module-is-being-loaded */
3620                if (mod->state == MODULE_STATE_COMING)
3621                        buf[bx++] = '+';
3622                buf[bx++] = ')';
3623        }
3624        buf[bx] = '\0';
3625
3626        return buf;
3627}
3628
3629#ifdef CONFIG_PROC_FS
3630/* Called by the /proc file system to return a list of modules. */
3631static void *m_start(struct seq_file *m, loff_t *pos)
3632{
3633        mutex_lock(&module_mutex);
3634        return seq_list_start(&modules, *pos);
3635}
3636
3637static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3638{
3639        return seq_list_next(p, &modules, pos);
3640}
3641
3642static void m_stop(struct seq_file *m, void *p)
3643{
3644        mutex_unlock(&module_mutex);
3645}
3646
3647static int m_show(struct seq_file *m, void *p)
3648{
3649        struct module *mod = list_entry(p, struct module, list);
3650        char buf[8];
3651
3652        /* We always ignore unformed modules. */
3653        if (mod->state == MODULE_STATE_UNFORMED)
3654                return 0;
3655
3656        seq_printf(m, "%s %u",
3657                   mod->name, mod->init_size + mod->core_size);
3658        print_unload_info(m, mod);
3659
3660        /* Informative for users. */
3661        seq_printf(m, " %s",
3662                   mod->state == MODULE_STATE_GOING ? "Unloading":
3663                   mod->state == MODULE_STATE_COMING ? "Loading":
3664                   "Live");
3665        /* Used by oprofile and other similar tools. */
3666        seq_printf(m, " 0x%pK", mod->module_core);
3667
3668        /* Taints info */
3669        if (mod->taints)
3670                seq_printf(m, " %s", module_flags(mod, buf));
3671
3672        seq_printf(m, "\n");
3673        return 0;
3674}
3675
3676/* Format: modulename size refcount deps address
3677
3678   Where refcount is a number or -, and deps is a comma-separated list
3679   of depends or -.
3680*/
3681static const struct seq_operations modules_op = {
3682        .start  = m_start,
3683        .next   = m_next,
3684        .stop   = m_stop,
3685        .show   = m_show
3686};
3687
3688static int modules_open(struct inode *inode, struct file *file)
3689{
3690        return seq_open(file, &modules_op);
3691}
3692
3693static const struct file_operations proc_modules_operations = {
3694        .open           = modules_open,
3695        .read           = seq_read,
3696        .llseek         = seq_lseek,
3697        .release        = seq_release,
3698};
3699
3700static int __init proc_modules_init(void)
3701{
3702        proc_create("modules", 0, NULL, &proc_modules_operations);
3703        return 0;
3704}
3705module_init(proc_modules_init);
3706#endif
3707
3708/* Given an address, look for it in the module exception tables. */
3709const struct exception_table_entry *search_module_extables(unsigned long addr)
3710{
3711        const struct exception_table_entry *e = NULL;
3712        struct module *mod;
3713
3714        preempt_disable();
3715        list_for_each_entry_rcu(mod, &modules, list) {
3716                if (mod->state == MODULE_STATE_UNFORMED)
3717                        continue;
3718                if (mod->num_exentries == 0)
3719                        continue;
3720
3721                e = search_extable(mod->extable,
3722                                   mod->extable + mod->num_exentries - 1,
3723                                   addr);
3724                if (e)
3725                        break;
3726        }
3727        preempt_enable();
3728
3729        /* Now, if we found one, we are running inside it now, hence
3730           we cannot unload the module, hence no refcnt needed. */
3731        return e;
3732}
3733
3734/*
3735 * is_module_address - is this address inside a module?
3736 * @addr: the address to check.
3737 *
3738 * See is_module_text_address() if you simply want to see if the address
3739 * is code (not data).
3740 */
3741bool is_module_address(unsigned long addr)
3742{
3743        bool ret;
3744
3745        preempt_disable();
3746        ret = __module_address(addr) != NULL;
3747        preempt_enable();
3748
3749        return ret;
3750}
3751
3752/*
3753 * __module_address - get the module which contains an address.
3754 * @addr: the address.
3755 *
3756 * Must be called with preempt disabled or module mutex held so that
3757 * module doesn't get freed during this.
3758 */
3759struct module *__module_address(unsigned long addr)
3760{
3761        struct module *mod;
3762
3763        if (addr < module_addr_min || addr > module_addr_max)
3764                return NULL;
3765
3766        list_for_each_entry_rcu(mod, &modules, list) {
3767                if (mod->state == MODULE_STATE_UNFORMED)
3768                        continue;
3769                if (within_module_core(addr, mod)
3770                    || within_module_init(addr, mod))
3771                        return mod;
3772        }
3773        return NULL;
3774}
3775EXPORT_SYMBOL_GPL(__module_address);
3776
3777/*
3778 * is_module_text_address - is this address inside module code?
3779 * @addr: the address to check.
3780 *
3781 * See is_module_address() if you simply want to see if the address is
3782 * anywhere in a module.  See kernel_text_address() for testing if an
3783 * address corresponds to kernel or module code.
3784 */
3785bool is_module_text_address(unsigned long addr)
3786{
3787        bool ret;
3788
3789        preempt_disable();
3790        ret = __module_text_address(addr) != NULL;
3791        preempt_enable();
3792
3793        return ret;
3794}
3795
3796/*
3797 * __module_text_address - get the module whose code contains an address.
3798 * @addr: the address.
3799 *
3800 * Must be called with preempt disabled or module mutex held so that
3801 * module doesn't get freed during this.
3802 */
3803struct module *__module_text_address(unsigned long addr)
3804{
3805        struct module *mod = __module_address(addr);
3806        if (mod) {
3807                /* Make sure it's within the text section. */
3808                if (!within(addr, mod->module_init, mod->init_text_size)
3809                    && !within(addr, mod->module_core, mod->core_text_size))
3810                        mod = NULL;
3811        }
3812        return mod;
3813}
3814EXPORT_SYMBOL_GPL(__module_text_address);
3815
3816/* Don't grab lock, we're oopsing. */
3817void print_modules(void)
3818{
3819        struct module *mod;
3820        char buf[8];
3821
3822        printk(KERN_DEFAULT "Modules linked in:");
3823        /* Most callers should already have preempt disabled, but make sure */
3824        preempt_disable();
3825        list_for_each_entry_rcu(mod, &modules, list) {
3826                if (mod->state == MODULE_STATE_UNFORMED)
3827                        continue;
3828                printk(" %s%s", mod->name, module_flags(mod, buf));
3829        }
3830        preempt_enable();
3831        if (last_unloaded_module[0])
3832                printk(" [last unloaded: %s]", last_unloaded_module);
3833        printk("\n");
3834}
3835
3836#ifdef CONFIG_MODVERSIONS
3837/* Generate the signature for all relevant module structures here.
3838 * If these change, we don't want to try to parse the module. */
3839void module_layout(struct module *mod,
3840                   struct modversion_info *ver,
3841                   struct kernel_param *kp,
3842                   struct kernel_symbol *ks,
3843                   struct tracepoint * const *tp)
3844{
3845}
3846EXPORT_SYMBOL(module_layout);
3847#endif
3848
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