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