linux/kernel/kexec.c
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   1/*
   2 * kexec.c - kexec system call
   3 * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
   4 *
   5 * This source code is licensed under the GNU General Public License,
   6 * Version 2.  See the file COPYING for more details.
   7 */
   8
   9#include <linux/capability.h>
  10#include <linux/mm.h>
  11#include <linux/file.h>
  12#include <linux/slab.h>
  13#include <linux/fs.h>
  14#include <linux/kexec.h>
  15#include <linux/mutex.h>
  16#include <linux/list.h>
  17#include <linux/highmem.h>
  18#include <linux/syscalls.h>
  19#include <linux/reboot.h>
  20#include <linux/ioport.h>
  21#include <linux/hardirq.h>
  22#include <linux/elf.h>
  23#include <linux/elfcore.h>
  24#include <generated/utsrelease.h>
  25#include <linux/utsname.h>
  26#include <linux/numa.h>
  27#include <linux/suspend.h>
  28#include <linux/device.h>
  29#include <linux/freezer.h>
  30#include <linux/pm.h>
  31#include <linux/cpu.h>
  32#include <linux/console.h>
  33#include <linux/vmalloc.h>
  34#include <linux/swap.h>
  35#include <linux/kmsg_dump.h>
  36#include <linux/syscore_ops.h>
  37
  38#include <asm/page.h>
  39#include <asm/uaccess.h>
  40#include <asm/io.h>
  41#include <asm/system.h>
  42#include <asm/sections.h>
  43
  44/* Per cpu memory for storing cpu states in case of system crash. */
  45note_buf_t __percpu *crash_notes;
  46
  47/* vmcoreinfo stuff */
  48static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
  49u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
  50size_t vmcoreinfo_size;
  51size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
  52
  53/* Location of the reserved area for the crash kernel */
  54struct resource crashk_res = {
  55        .name  = "Crash kernel",
  56        .start = 0,
  57        .end   = 0,
  58        .flags = IORESOURCE_BUSY | IORESOURCE_MEM
  59};
  60
  61int kexec_should_crash(struct task_struct *p)
  62{
  63        if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)
  64                return 1;
  65        return 0;
  66}
  67
  68/*
  69 * When kexec transitions to the new kernel there is a one-to-one
  70 * mapping between physical and virtual addresses.  On processors
  71 * where you can disable the MMU this is trivial, and easy.  For
  72 * others it is still a simple predictable page table to setup.
  73 *
  74 * In that environment kexec copies the new kernel to its final
  75 * resting place.  This means I can only support memory whose
  76 * physical address can fit in an unsigned long.  In particular
  77 * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
  78 * If the assembly stub has more restrictive requirements
  79 * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
  80 * defined more restrictively in <asm/kexec.h>.
  81 *
  82 * The code for the transition from the current kernel to the
  83 * the new kernel is placed in the control_code_buffer, whose size
  84 * is given by KEXEC_CONTROL_PAGE_SIZE.  In the best case only a single
  85 * page of memory is necessary, but some architectures require more.
  86 * Because this memory must be identity mapped in the transition from
  87 * virtual to physical addresses it must live in the range
  88 * 0 - TASK_SIZE, as only the user space mappings are arbitrarily
  89 * modifiable.
  90 *
  91 * The assembly stub in the control code buffer is passed a linked list
  92 * of descriptor pages detailing the source pages of the new kernel,
  93 * and the destination addresses of those source pages.  As this data
  94 * structure is not used in the context of the current OS, it must
  95 * be self-contained.
  96 *
  97 * The code has been made to work with highmem pages and will use a
  98 * destination page in its final resting place (if it happens
  99 * to allocate it).  The end product of this is that most of the
 100 * physical address space, and most of RAM can be used.
 101 *
 102 * Future directions include:
 103 *  - allocating a page table with the control code buffer identity
 104 *    mapped, to simplify machine_kexec and make kexec_on_panic more
 105 *    reliable.
 106 */
 107
 108/*
 109 * KIMAGE_NO_DEST is an impossible destination address..., for
 110 * allocating pages whose destination address we do not care about.
 111 */
 112#define KIMAGE_NO_DEST (-1UL)
 113
 114static int kimage_is_destination_range(struct kimage *image,
 115                                       unsigned long start, unsigned long end);
 116static struct page *kimage_alloc_page(struct kimage *image,
 117                                       gfp_t gfp_mask,
 118                                       unsigned long dest);
 119
 120static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
 121                            unsigned long nr_segments,
 122                            struct kexec_segment __user *segments)
 123{
 124        size_t segment_bytes;
 125        struct kimage *image;
 126        unsigned long i;
 127        int result;
 128
 129        /* Allocate a controlling structure */
 130        result = -ENOMEM;
 131        image = kzalloc(sizeof(*image), GFP_KERNEL);
 132        if (!image)
 133                goto out;
 134
 135        image->head = 0;
 136        image->entry = &image->head;
 137        image->last_entry = &image->head;
 138        image->control_page = ~0; /* By default this does not apply */
 139        image->start = entry;
 140        image->type = KEXEC_TYPE_DEFAULT;
 141
 142        /* Initialize the list of control pages */
 143        INIT_LIST_HEAD(&image->control_pages);
 144
 145        /* Initialize the list of destination pages */
 146        INIT_LIST_HEAD(&image->dest_pages);
 147
 148        /* Initialize the list of unusable pages */
 149        INIT_LIST_HEAD(&image->unuseable_pages);
 150
 151        /* Read in the segments */
 152        image->nr_segments = nr_segments;
 153        segment_bytes = nr_segments * sizeof(*segments);
 154        result = copy_from_user(image->segment, segments, segment_bytes);
 155        if (result) {
 156                result = -EFAULT;
 157                goto out;
 158        }
 159
 160        /*
 161         * Verify we have good destination addresses.  The caller is
 162         * responsible for making certain we don't attempt to load
 163         * the new image into invalid or reserved areas of RAM.  This
 164         * just verifies it is an address we can use.
 165         *
 166         * Since the kernel does everything in page size chunks ensure
 167         * the destination addresses are page aligned.  Too many
 168         * special cases crop of when we don't do this.  The most
 169         * insidious is getting overlapping destination addresses
 170         * simply because addresses are changed to page size
 171         * granularity.
 172         */
 173        result = -EADDRNOTAVAIL;
 174        for (i = 0; i < nr_segments; i++) {
 175                unsigned long mstart, mend;
 176
 177                mstart = image->segment[i].mem;
 178                mend   = mstart + image->segment[i].memsz;
 179                if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
 180                        goto out;
 181                if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
 182                        goto out;
 183        }
 184
 185        /* Verify our destination addresses do not overlap.
 186         * If we alloed overlapping destination addresses
 187         * through very weird things can happen with no
 188         * easy explanation as one segment stops on another.
 189         */
 190        result = -EINVAL;
 191        for (i = 0; i < nr_segments; i++) {
 192                unsigned long mstart, mend;
 193                unsigned long j;
 194
 195                mstart = image->segment[i].mem;
 196                mend   = mstart + image->segment[i].memsz;
 197                for (j = 0; j < i; j++) {
 198                        unsigned long pstart, pend;
 199                        pstart = image->segment[j].mem;
 200                        pend   = pstart + image->segment[j].memsz;
 201                        /* Do the segments overlap ? */
 202                        if ((mend > pstart) && (mstart < pend))
 203                                goto out;
 204                }
 205        }
 206
 207        /* Ensure our buffer sizes are strictly less than
 208         * our memory sizes.  This should always be the case,
 209         * and it is easier to check up front than to be surprised
 210         * later on.
 211         */
 212        result = -EINVAL;
 213        for (i = 0; i < nr_segments; i++) {
 214                if (image->segment[i].bufsz > image->segment[i].memsz)
 215                        goto out;
 216        }
 217
 218        result = 0;
 219out:
 220        if (result == 0)
 221                *rimage = image;
 222        else
 223                kfree(image);
 224
 225        return result;
 226
 227}
 228
 229static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
 230                                unsigned long nr_segments,
 231                                struct kexec_segment __user *segments)
 232{
 233        int result;
 234        struct kimage *image;
 235
 236        /* Allocate and initialize a controlling structure */
 237        image = NULL;
 238        result = do_kimage_alloc(&image, entry, nr_segments, segments);
 239        if (result)
 240                goto out;
 241
 242        *rimage = image;
 243
 244        /*
 245         * Find a location for the control code buffer, and add it
 246         * the vector of segments so that it's pages will also be
 247         * counted as destination pages.
 248         */
 249        result = -ENOMEM;
 250        image->control_code_page = kimage_alloc_control_pages(image,
 251                                           get_order(KEXEC_CONTROL_PAGE_SIZE));
 252        if (!image->control_code_page) {
 253                printk(KERN_ERR "Could not allocate control_code_buffer\n");
 254                goto out;
 255        }
 256
 257        image->swap_page = kimage_alloc_control_pages(image, 0);
 258        if (!image->swap_page) {
 259                printk(KERN_ERR "Could not allocate swap buffer\n");
 260                goto out;
 261        }
 262
 263        result = 0;
 264 out:
 265        if (result == 0)
 266                *rimage = image;
 267        else
 268                kfree(image);
 269
 270        return result;
 271}
 272
 273static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
 274                                unsigned long nr_segments,
 275                                struct kexec_segment __user *segments)
 276{
 277        int result;
 278        struct kimage *image;
 279        unsigned long i;
 280
 281        image = NULL;
 282        /* Verify we have a valid entry point */
 283        if ((entry < crashk_res.start) || (entry > crashk_res.end)) {
 284                result = -EADDRNOTAVAIL;
 285                goto out;
 286        }
 287
 288        /* Allocate and initialize a controlling structure */
 289        result = do_kimage_alloc(&image, entry, nr_segments, segments);
 290        if (result)
 291                goto out;
 292
 293        /* Enable the special crash kernel control page
 294         * allocation policy.
 295         */
 296        image->control_page = crashk_res.start;
 297        image->type = KEXEC_TYPE_CRASH;
 298
 299        /*
 300         * Verify we have good destination addresses.  Normally
 301         * the caller is responsible for making certain we don't
 302         * attempt to load the new image into invalid or reserved
 303         * areas of RAM.  But crash kernels are preloaded into a
 304         * reserved area of ram.  We must ensure the addresses
 305         * are in the reserved area otherwise preloading the
 306         * kernel could corrupt things.
 307         */
 308        result = -EADDRNOTAVAIL;
 309        for (i = 0; i < nr_segments; i++) {
 310                unsigned long mstart, mend;
 311
 312                mstart = image->segment[i].mem;
 313                mend = mstart + image->segment[i].memsz - 1;
 314                /* Ensure we are within the crash kernel limits */
 315                if ((mstart < crashk_res.start) || (mend > crashk_res.end))
 316                        goto out;
 317        }
 318
 319        /*
 320         * Find a location for the control code buffer, and add
 321         * the vector of segments so that it's pages will also be
 322         * counted as destination pages.
 323         */
 324        result = -ENOMEM;
 325        image->control_code_page = kimage_alloc_control_pages(image,
 326                                           get_order(KEXEC_CONTROL_PAGE_SIZE));
 327        if (!image->control_code_page) {
 328                printk(KERN_ERR "Could not allocate control_code_buffer\n");
 329                goto out;
 330        }
 331
 332        result = 0;
 333out:
 334        if (result == 0)
 335                *rimage = image;
 336        else
 337                kfree(image);
 338
 339        return result;
 340}
 341
 342static int kimage_is_destination_range(struct kimage *image,
 343                                        unsigned long start,
 344                                        unsigned long end)
 345{
 346        unsigned long i;
 347
 348        for (i = 0; i < image->nr_segments; i++) {
 349                unsigned long mstart, mend;
 350
 351                mstart = image->segment[i].mem;
 352                mend = mstart + image->segment[i].memsz;
 353                if ((end > mstart) && (start < mend))
 354                        return 1;
 355        }
 356
 357        return 0;
 358}
 359
 360static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
 361{
 362        struct page *pages;
 363
 364        pages = alloc_pages(gfp_mask, order);
 365        if (pages) {
 366                unsigned int count, i;
 367                pages->mapping = NULL;
 368                set_page_private(pages, order);
 369                count = 1 << order;
 370                for (i = 0; i < count; i++)
 371                        SetPageReserved(pages + i);
 372        }
 373
 374        return pages;
 375}
 376
 377static void kimage_free_pages(struct page *page)
 378{
 379        unsigned int order, count, i;
 380
 381        order = page_private(page);
 382        count = 1 << order;
 383        for (i = 0; i < count; i++)
 384                ClearPageReserved(page + i);
 385        __free_pages(page, order);
 386}
 387
 388static void kimage_free_page_list(struct list_head *list)
 389{
 390        struct list_head *pos, *next;
 391
 392        list_for_each_safe(pos, next, list) {
 393                struct page *page;
 394
 395                page = list_entry(pos, struct page, lru);
 396                list_del(&page->lru);
 397                kimage_free_pages(page);
 398        }
 399}
 400
 401static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
 402                                                        unsigned int order)
 403{
 404        /* Control pages are special, they are the intermediaries
 405         * that are needed while we copy the rest of the pages
 406         * to their final resting place.  As such they must
 407         * not conflict with either the destination addresses
 408         * or memory the kernel is already using.
 409         *
 410         * The only case where we really need more than one of
 411         * these are for architectures where we cannot disable
 412         * the MMU and must instead generate an identity mapped
 413         * page table for all of the memory.
 414         *
 415         * At worst this runs in O(N) of the image size.
 416         */
 417        struct list_head extra_pages;
 418        struct page *pages;
 419        unsigned int count;
 420
 421        count = 1 << order;
 422        INIT_LIST_HEAD(&extra_pages);
 423
 424        /* Loop while I can allocate a page and the page allocated
 425         * is a destination page.
 426         */
 427        do {
 428                unsigned long pfn, epfn, addr, eaddr;
 429
 430                pages = kimage_alloc_pages(GFP_KERNEL, order);
 431                if (!pages)
 432                        break;
 433                pfn   = page_to_pfn(pages);
 434                epfn  = pfn + count;
 435                addr  = pfn << PAGE_SHIFT;
 436                eaddr = epfn << PAGE_SHIFT;
 437                if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
 438                              kimage_is_destination_range(image, addr, eaddr)) {
 439                        list_add(&pages->lru, &extra_pages);
 440                        pages = NULL;
 441                }
 442        } while (!pages);
 443
 444        if (pages) {
 445                /* Remember the allocated page... */
 446                list_add(&pages->lru, &image->control_pages);
 447
 448                /* Because the page is already in it's destination
 449                 * location we will never allocate another page at
 450                 * that address.  Therefore kimage_alloc_pages
 451                 * will not return it (again) and we don't need
 452                 * to give it an entry in image->segment[].
 453                 */
 454        }
 455        /* Deal with the destination pages I have inadvertently allocated.
 456         *
 457         * Ideally I would convert multi-page allocations into single
 458         * page allocations, and add everything to image->dest_pages.
 459         *
 460         * For now it is simpler to just free the pages.
 461         */
 462        kimage_free_page_list(&extra_pages);
 463
 464        return pages;
 465}
 466
 467static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
 468                                                      unsigned int order)
 469{
 470        /* Control pages are special, they are the intermediaries
 471         * that are needed while we copy the rest of the pages
 472         * to their final resting place.  As such they must
 473         * not conflict with either the destination addresses
 474         * or memory the kernel is already using.
 475         *
 476         * Control pages are also the only pags we must allocate
 477         * when loading a crash kernel.  All of the other pages
 478         * are specified by the segments and we just memcpy
 479         * into them directly.
 480         *
 481         * The only case where we really need more than one of
 482         * these are for architectures where we cannot disable
 483         * the MMU and must instead generate an identity mapped
 484         * page table for all of the memory.
 485         *
 486         * Given the low demand this implements a very simple
 487         * allocator that finds the first hole of the appropriate
 488         * size in the reserved memory region, and allocates all
 489         * of the memory up to and including the hole.
 490         */
 491        unsigned long hole_start, hole_end, size;
 492        struct page *pages;
 493
 494        pages = NULL;
 495        size = (1 << order) << PAGE_SHIFT;
 496        hole_start = (image->control_page + (size - 1)) & ~(size - 1);
 497        hole_end   = hole_start + size - 1;
 498        while (hole_end <= crashk_res.end) {
 499                unsigned long i;
 500
 501                if (hole_end > KEXEC_CONTROL_MEMORY_LIMIT)
 502                        break;
 503                if (hole_end > crashk_res.end)
 504                        break;
 505                /* See if I overlap any of the segments */
 506                for (i = 0; i < image->nr_segments; i++) {
 507                        unsigned long mstart, mend;
 508
 509                        mstart = image->segment[i].mem;
 510                        mend   = mstart + image->segment[i].memsz - 1;
 511                        if ((hole_end >= mstart) && (hole_start <= mend)) {
 512                                /* Advance the hole to the end of the segment */
 513                                hole_start = (mend + (size - 1)) & ~(size - 1);
 514                                hole_end   = hole_start + size - 1;
 515                                break;
 516                        }
 517                }
 518                /* If I don't overlap any segments I have found my hole! */
 519                if (i == image->nr_segments) {
 520                        pages = pfn_to_page(hole_start >> PAGE_SHIFT);
 521                        break;
 522                }
 523        }
 524        if (pages)
 525                image->control_page = hole_end;
 526
 527        return pages;
 528}
 529
 530
 531struct page *kimage_alloc_control_pages(struct kimage *image,
 532                                         unsigned int order)
 533{
 534        struct page *pages = NULL;
 535
 536        switch (image->type) {
 537        case KEXEC_TYPE_DEFAULT:
 538                pages = kimage_alloc_normal_control_pages(image, order);
 539                break;
 540        case KEXEC_TYPE_CRASH:
 541                pages = kimage_alloc_crash_control_pages(image, order);
 542                break;
 543        }
 544
 545        return pages;
 546}
 547
 548static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
 549{
 550        if (*image->entry != 0)
 551                image->entry++;
 552
 553        if (image->entry == image->last_entry) {
 554                kimage_entry_t *ind_page;
 555                struct page *page;
 556
 557                page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
 558                if (!page)
 559                        return -ENOMEM;
 560
 561                ind_page = page_address(page);
 562                *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
 563                image->entry = ind_page;
 564                image->last_entry = ind_page +
 565                                      ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
 566        }
 567        *image->entry = entry;
 568        image->entry++;
 569        *image->entry = 0;
 570
 571        return 0;
 572}
 573
 574static int kimage_set_destination(struct kimage *image,
 575                                   unsigned long destination)
 576{
 577        int result;
 578
 579        destination &= PAGE_MASK;
 580        result = kimage_add_entry(image, destination | IND_DESTINATION);
 581        if (result == 0)
 582                image->destination = destination;
 583
 584        return result;
 585}
 586
 587
 588static int kimage_add_page(struct kimage *image, unsigned long page)
 589{
 590        int result;
 591
 592        page &= PAGE_MASK;
 593        result = kimage_add_entry(image, page | IND_SOURCE);
 594        if (result == 0)
 595                image->destination += PAGE_SIZE;
 596
 597        return result;
 598}
 599
 600
 601static void kimage_free_extra_pages(struct kimage *image)
 602{
 603        /* Walk through and free any extra destination pages I may have */
 604        kimage_free_page_list(&image->dest_pages);
 605
 606        /* Walk through and free any unusable pages I have cached */
 607        kimage_free_page_list(&image->unuseable_pages);
 608
 609}
 610static void kimage_terminate(struct kimage *image)
 611{
 612        if (*image->entry != 0)
 613                image->entry++;
 614
 615        *image->entry = IND_DONE;
 616}
 617
 618#define for_each_kimage_entry(image, ptr, entry) \
 619        for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
 620                ptr = (entry & IND_INDIRECTION)? \
 621                        phys_to_virt((entry & PAGE_MASK)): ptr +1)
 622
 623static void kimage_free_entry(kimage_entry_t entry)
 624{
 625        struct page *page;
 626
 627        page = pfn_to_page(entry >> PAGE_SHIFT);
 628        kimage_free_pages(page);
 629}
 630
 631static void kimage_free(struct kimage *image)
 632{
 633        kimage_entry_t *ptr, entry;
 634        kimage_entry_t ind = 0;
 635
 636        if (!image)
 637                return;
 638
 639        kimage_free_extra_pages(image);
 640        for_each_kimage_entry(image, ptr, entry) {
 641                if (entry & IND_INDIRECTION) {
 642                        /* Free the previous indirection page */
 643                        if (ind & IND_INDIRECTION)
 644                                kimage_free_entry(ind);
 645                        /* Save this indirection page until we are
 646                         * done with it.
 647                         */
 648                        ind = entry;
 649                }
 650                else if (entry & IND_SOURCE)
 651                        kimage_free_entry(entry);
 652        }
 653        /* Free the final indirection page */
 654        if (ind & IND_INDIRECTION)
 655                kimage_free_entry(ind);
 656
 657        /* Handle any machine specific cleanup */
 658        machine_kexec_cleanup(image);
 659
 660        /* Free the kexec control pages... */
 661        kimage_free_page_list(&image->control_pages);
 662        kfree(image);
 663}
 664
 665static kimage_entry_t *kimage_dst_used(struct kimage *image,
 666                                        unsigned long page)
 667{
 668        kimage_entry_t *ptr, entry;
 669        unsigned long destination = 0;
 670
 671        for_each_kimage_entry(image, ptr, entry) {
 672                if (entry & IND_DESTINATION)
 673                        destination = entry & PAGE_MASK;
 674                else if (entry & IND_SOURCE) {
 675                        if (page == destination)
 676                                return ptr;
 677                        destination += PAGE_SIZE;
 678                }
 679        }
 680
 681        return NULL;
 682}
 683
 684static struct page *kimage_alloc_page(struct kimage *image,
 685                                        gfp_t gfp_mask,
 686                                        unsigned long destination)
 687{
 688        /*
 689         * Here we implement safeguards to ensure that a source page
 690         * is not copied to its destination page before the data on
 691         * the destination page is no longer useful.
 692         *
 693         * To do this we maintain the invariant that a source page is
 694         * either its own destination page, or it is not a
 695         * destination page at all.
 696         *
 697         * That is slightly stronger than required, but the proof
 698         * that no problems will not occur is trivial, and the
 699         * implementation is simply to verify.
 700         *
 701         * When allocating all pages normally this algorithm will run
 702         * in O(N) time, but in the worst case it will run in O(N^2)
 703         * time.   If the runtime is a problem the data structures can
 704         * be fixed.
 705         */
 706        struct page *page;
 707        unsigned long addr;
 708
 709        /*
 710         * Walk through the list of destination pages, and see if I
 711         * have a match.
 712         */
 713        list_for_each_entry(page, &image->dest_pages, lru) {
 714                addr = page_to_pfn(page) << PAGE_SHIFT;
 715                if (addr == destination) {
 716                        list_del(&page->lru);
 717                        return page;
 718                }
 719        }
 720        page = NULL;
 721        while (1) {
 722                kimage_entry_t *old;
 723
 724                /* Allocate a page, if we run out of memory give up */
 725                page = kimage_alloc_pages(gfp_mask, 0);
 726                if (!page)
 727                        return NULL;
 728                /* If the page cannot be used file it away */
 729                if (page_to_pfn(page) >
 730                                (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
 731                        list_add(&page->lru, &image->unuseable_pages);
 732                        continue;
 733                }
 734                addr = page_to_pfn(page) << PAGE_SHIFT;
 735
 736                /* If it is the destination page we want use it */
 737                if (addr == destination)
 738                        break;
 739
 740                /* If the page is not a destination page use it */
 741                if (!kimage_is_destination_range(image, addr,
 742                                                  addr + PAGE_SIZE))
 743                        break;
 744
 745                /*
 746                 * I know that the page is someones destination page.
 747                 * See if there is already a source page for this
 748                 * destination page.  And if so swap the source pages.
 749                 */
 750                old = kimage_dst_used(image, addr);
 751                if (old) {
 752                        /* If so move it */
 753                        unsigned long old_addr;
 754                        struct page *old_page;
 755
 756                        old_addr = *old & PAGE_MASK;
 757                        old_page = pfn_to_page(old_addr >> PAGE_SHIFT);
 758                        copy_highpage(page, old_page);
 759                        *old = addr | (*old & ~PAGE_MASK);
 760
 761                        /* The old page I have found cannot be a
 762                         * destination page, so return it if it's
 763                         * gfp_flags honor the ones passed in.
 764                         */
 765                        if (!(gfp_mask & __GFP_HIGHMEM) &&
 766                            PageHighMem(old_page)) {
 767                                kimage_free_pages(old_page);
 768                                continue;
 769                        }
 770                        addr = old_addr;
 771                        page = old_page;
 772                        break;
 773                }
 774                else {
 775                        /* Place the page on the destination list I
 776                         * will use it later.
 777                         */
 778                        list_add(&page->lru, &image->dest_pages);
 779                }
 780        }
 781
 782        return page;
 783}
 784
 785static int kimage_load_normal_segment(struct kimage *image,
 786                                         struct kexec_segment *segment)
 787{
 788        unsigned long maddr;
 789        unsigned long ubytes, mbytes;
 790        int result;
 791        unsigned char __user *buf;
 792
 793        result = 0;
 794        buf = segment->buf;
 795        ubytes = segment->bufsz;
 796        mbytes = segment->memsz;
 797        maddr = segment->mem;
 798
 799        result = kimage_set_destination(image, maddr);
 800        if (result < 0)
 801                goto out;
 802
 803        while (mbytes) {
 804                struct page *page;
 805                char *ptr;
 806                size_t uchunk, mchunk;
 807
 808                page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
 809                if (!page) {
 810                        result  = -ENOMEM;
 811                        goto out;
 812                }
 813                result = kimage_add_page(image, page_to_pfn(page)
 814                                                                << PAGE_SHIFT);
 815                if (result < 0)
 816                        goto out;
 817
 818                ptr = kmap(page);
 819                /* Start with a clear page */
 820                clear_page(ptr);
 821                ptr += maddr & ~PAGE_MASK;
 822                mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
 823                if (mchunk > mbytes)
 824                        mchunk = mbytes;
 825
 826                uchunk = mchunk;
 827                if (uchunk > ubytes)
 828                        uchunk = ubytes;
 829
 830                result = copy_from_user(ptr, buf, uchunk);
 831                kunmap(page);
 832                if (result) {
 833                        result = -EFAULT;
 834                        goto out;
 835                }
 836                ubytes -= uchunk;
 837                maddr  += mchunk;
 838                buf    += mchunk;
 839                mbytes -= mchunk;
 840        }
 841out:
 842        return result;
 843}
 844
 845static int kimage_load_crash_segment(struct kimage *image,
 846                                        struct kexec_segment *segment)
 847{
 848        /* For crash dumps kernels we simply copy the data from
 849         * user space to it's destination.
 850         * We do things a page at a time for the sake of kmap.
 851         */
 852        unsigned long maddr;
 853        unsigned long ubytes, mbytes;
 854        int result;
 855        unsigned char __user *buf;
 856
 857        result = 0;
 858        buf = segment->buf;
 859        ubytes = segment->bufsz;
 860        mbytes = segment->memsz;
 861        maddr = segment->mem;
 862        while (mbytes) {
 863                struct page *page;
 864                char *ptr;
 865                size_t uchunk, mchunk;
 866
 867                page = pfn_to_page(maddr >> PAGE_SHIFT);
 868                if (!page) {
 869                        result  = -ENOMEM;
 870                        goto out;
 871                }
 872                ptr = kmap(page);
 873                ptr += maddr & ~PAGE_MASK;
 874                mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
 875                if (mchunk > mbytes)
 876                        mchunk = mbytes;
 877
 878                uchunk = mchunk;
 879                if (uchunk > ubytes) {
 880                        uchunk = ubytes;
 881                        /* Zero the trailing part of the page */
 882                        memset(ptr + uchunk, 0, mchunk - uchunk);
 883                }
 884                result = copy_from_user(ptr, buf, uchunk);
 885                kexec_flush_icache_page(page);
 886                kunmap(page);
 887                if (result) {
 888                        result = -EFAULT;
 889                        goto out;
 890                }
 891                ubytes -= uchunk;
 892                maddr  += mchunk;
 893                buf    += mchunk;
 894                mbytes -= mchunk;
 895        }
 896out:
 897        return result;
 898}
 899
 900static int kimage_load_segment(struct kimage *image,
 901                                struct kexec_segment *segment)
 902{
 903        int result = -ENOMEM;
 904
 905        switch (image->type) {
 906        case KEXEC_TYPE_DEFAULT:
 907                result = kimage_load_normal_segment(image, segment);
 908                break;
 909        case KEXEC_TYPE_CRASH:
 910                result = kimage_load_crash_segment(image, segment);
 911                break;
 912        }
 913
 914        return result;
 915}
 916
 917/*
 918 * Exec Kernel system call: for obvious reasons only root may call it.
 919 *
 920 * This call breaks up into three pieces.
 921 * - A generic part which loads the new kernel from the current
 922 *   address space, and very carefully places the data in the
 923 *   allocated pages.
 924 *
 925 * - A generic part that interacts with the kernel and tells all of
 926 *   the devices to shut down.  Preventing on-going dmas, and placing
 927 *   the devices in a consistent state so a later kernel can
 928 *   reinitialize them.
 929 *
 930 * - A machine specific part that includes the syscall number
 931 *   and the copies the image to it's final destination.  And
 932 *   jumps into the image at entry.
 933 *
 934 * kexec does not sync, or unmount filesystems so if you need
 935 * that to happen you need to do that yourself.
 936 */
 937struct kimage *kexec_image;
 938struct kimage *kexec_crash_image;
 939
 940static DEFINE_MUTEX(kexec_mutex);
 941
 942SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
 943                struct kexec_segment __user *, segments, unsigned long, flags)
 944{
 945        struct kimage **dest_image, *image;
 946        int result;
 947
 948        /* We only trust the superuser with rebooting the system. */
 949        if (!capable(CAP_SYS_BOOT))
 950                return -EPERM;
 951
 952        /*
 953         * Verify we have a legal set of flags
 954         * This leaves us room for future extensions.
 955         */
 956        if ((flags & KEXEC_FLAGS) != (flags & ~KEXEC_ARCH_MASK))
 957                return -EINVAL;
 958
 959        /* Verify we are on the appropriate architecture */
 960        if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) &&
 961                ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
 962                return -EINVAL;
 963
 964        /* Put an artificial cap on the number
 965         * of segments passed to kexec_load.
 966         */
 967        if (nr_segments > KEXEC_SEGMENT_MAX)
 968                return -EINVAL;
 969
 970        image = NULL;
 971        result = 0;
 972
 973        /* Because we write directly to the reserved memory
 974         * region when loading crash kernels we need a mutex here to
 975         * prevent multiple crash  kernels from attempting to load
 976         * simultaneously, and to prevent a crash kernel from loading
 977         * over the top of a in use crash kernel.
 978         *
 979         * KISS: always take the mutex.
 980         */
 981        if (!mutex_trylock(&kexec_mutex))
 982                return -EBUSY;
 983
 984        dest_image = &kexec_image;
 985        if (flags & KEXEC_ON_CRASH)
 986                dest_image = &kexec_crash_image;
 987        if (nr_segments > 0) {
 988                unsigned long i;
 989
 990                /* Loading another kernel to reboot into */
 991                if ((flags & KEXEC_ON_CRASH) == 0)
 992                        result = kimage_normal_alloc(&image, entry,
 993                                                        nr_segments, segments);
 994                /* Loading another kernel to switch to if this one crashes */
 995                else if (flags & KEXEC_ON_CRASH) {
 996                        /* Free any current crash dump kernel before
 997                         * we corrupt it.
 998                         */
 999                        kimage_free(xchg(&kexec_crash_image, NULL));
1000                        result = kimage_crash_alloc(&image, entry,
1001                                                     nr_segments, segments);
1002                }
1003                if (result)
1004                        goto out;
1005
1006                if (flags & KEXEC_PRESERVE_CONTEXT)
1007                        image->preserve_context = 1;
1008                result = machine_kexec_prepare(image);
1009                if (result)
1010                        goto out;
1011
1012                for (i = 0; i < nr_segments; i++) {
1013                        result = kimage_load_segment(image, &image->segment[i]);
1014                        if (result)
1015                                goto out;
1016                }
1017                kimage_terminate(image);
1018        }
1019        /* Install the new kernel, and  Uninstall the old */
1020        image = xchg(dest_image, image);
1021
1022out:
1023        mutex_unlock(&kexec_mutex);
1024        kimage_free(image);
1025
1026        return result;
1027}
1028
1029#ifdef CONFIG_COMPAT
1030asmlinkage long compat_sys_kexec_load(unsigned long entry,
1031                                unsigned long nr_segments,
1032                                struct compat_kexec_segment __user *segments,
1033                                unsigned long flags)
1034{
1035        struct compat_kexec_segment in;
1036        struct kexec_segment out, __user *ksegments;
1037        unsigned long i, result;
1038
1039        /* Don't allow clients that don't understand the native
1040         * architecture to do anything.
1041         */
1042        if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
1043                return -EINVAL;
1044
1045        if (nr_segments > KEXEC_SEGMENT_MAX)
1046                return -EINVAL;
1047
1048        ksegments = compat_alloc_user_space(nr_segments * sizeof(out));
1049        for (i=0; i < nr_segments; i++) {
1050                result = copy_from_user(&in, &segments[i], sizeof(in));
1051                if (result)
1052                        return -EFAULT;
1053
1054                out.buf   = compat_ptr(in.buf);
1055                out.bufsz = in.bufsz;
1056                out.mem   = in.mem;
1057                out.memsz = in.memsz;
1058
1059                result = copy_to_user(&ksegments[i], &out, sizeof(out));
1060                if (result)
1061                        return -EFAULT;
1062        }
1063
1064        return sys_kexec_load(entry, nr_segments, ksegments, flags);
1065}
1066#endif
1067
1068void crash_kexec(struct pt_regs *regs)
1069{
1070        /* Take the kexec_mutex here to prevent sys_kexec_load
1071         * running on one cpu from replacing the crash kernel
1072         * we are using after a panic on a different cpu.
1073         *
1074         * If the crash kernel was not located in a fixed area
1075         * of memory the xchg(&kexec_crash_image) would be
1076         * sufficient.  But since I reuse the memory...
1077         */
1078        if (mutex_trylock(&kexec_mutex)) {
1079                if (kexec_crash_image) {
1080                        struct pt_regs fixed_regs;
1081
1082                        kmsg_dump(KMSG_DUMP_KEXEC);
1083
1084                        crash_setup_regs(&fixed_regs, regs);
1085                        crash_save_vmcoreinfo();
1086                        machine_crash_shutdown(&fixed_regs);
1087                        machine_kexec(kexec_crash_image);
1088                }
1089                mutex_unlock(&kexec_mutex);
1090        }
1091}
1092
1093size_t crash_get_memory_size(void)
1094{
1095        size_t size = 0;
1096        mutex_lock(&kexec_mutex);
1097        if (crashk_res.end != crashk_res.start)
1098                size = resource_size(&crashk_res);
1099        mutex_unlock(&kexec_mutex);
1100        return size;
1101}
1102
1103void __weak crash_free_reserved_phys_range(unsigned long begin,
1104                                           unsigned long end)
1105{
1106        unsigned long addr;
1107
1108        for (addr = begin; addr < end; addr += PAGE_SIZE) {
1109                ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
1110                init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
1111                free_page((unsigned long)__va(addr));
1112                totalram_pages++;
1113        }
1114}
1115
1116int crash_shrink_memory(unsigned long new_size)
1117{
1118        int ret = 0;
1119        unsigned long start, end;
1120
1121        mutex_lock(&kexec_mutex);
1122
1123        if (kexec_crash_image) {
1124                ret = -ENOENT;
1125                goto unlock;
1126        }
1127        start = crashk_res.start;
1128        end = crashk_res.end;
1129
1130        if (new_size >= end - start + 1) {
1131                ret = -EINVAL;
1132                if (new_size == end - start + 1)
1133                        ret = 0;
1134                goto unlock;
1135        }
1136
1137        start = roundup(start, PAGE_SIZE);
1138        end = roundup(start + new_size, PAGE_SIZE);
1139
1140        crash_free_reserved_phys_range(end, crashk_res.end);
1141
1142        if ((start == end) && (crashk_res.parent != NULL))
1143                release_resource(&crashk_res);
1144        crashk_res.end = end - 1;
1145
1146unlock:
1147        mutex_unlock(&kexec_mutex);
1148        return ret;
1149}
1150
1151static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
1152                            size_t data_len)
1153{
1154        struct elf_note note;
1155
1156        note.n_namesz = strlen(name) + 1;
1157        note.n_descsz = data_len;
1158        note.n_type   = type;
1159        memcpy(buf, &note, sizeof(note));
1160        buf += (sizeof(note) + 3)/4;
1161        memcpy(buf, name, note.n_namesz);
1162        buf += (note.n_namesz + 3)/4;
1163        memcpy(buf, data, note.n_descsz);
1164        buf += (note.n_descsz + 3)/4;
1165
1166        return buf;
1167}
1168
1169static void final_note(u32 *buf)
1170{
1171        struct elf_note note;
1172
1173        note.n_namesz = 0;
1174        note.n_descsz = 0;
1175        note.n_type   = 0;
1176        memcpy(buf, &note, sizeof(note));
1177}
1178
1179void crash_save_cpu(struct pt_regs *regs, int cpu)
1180{
1181        struct elf_prstatus prstatus;
1182        u32 *buf;
1183
1184        if ((cpu < 0) || (cpu >= nr_cpu_ids))
1185                return;
1186
1187        /* Using ELF notes here is opportunistic.
1188         * I need a well defined structure format
1189         * for the data I pass, and I need tags
1190         * on the data to indicate what information I have
1191         * squirrelled away.  ELF notes happen to provide
1192         * all of that, so there is no need to invent something new.
1193         */
1194        buf = (u32*)per_cpu_ptr(crash_notes, cpu);
1195        if (!buf)
1196                return;
1197        memset(&prstatus, 0, sizeof(prstatus));
1198        prstatus.pr_pid = current->pid;
1199        elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
1200        buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
1201                              &prstatus, sizeof(prstatus));
1202        final_note(buf);
1203}
1204
1205static int __init crash_notes_memory_init(void)
1206{
1207        /* Allocate memory for saving cpu registers. */
1208        crash_notes = alloc_percpu(note_buf_t);
1209        if (!crash_notes) {
1210                printk("Kexec: Memory allocation for saving cpu register"
1211                " states failed\n");
1212                return -ENOMEM;
1213        }
1214        return 0;
1215}
1216module_init(crash_notes_memory_init)
1217
1218
1219/*
1220 * parsing the "crashkernel" commandline
1221 *
1222 * this code is intended to be called from architecture specific code
1223 */
1224
1225
1226/*
1227 * This function parses command lines in the format
1228 *
1229 *   crashkernel=ramsize-range:size[,...][@offset]
1230 *
1231 * The function returns 0 on success and -EINVAL on failure.
1232 */
1233static int __init parse_crashkernel_mem(char                    *cmdline,
1234                                        unsigned long long      system_ram,
1235                                        unsigned long long      *crash_size,
1236                                        unsigned long long      *crash_base)
1237{
1238        char *cur = cmdline, *tmp;
1239
1240        /* for each entry of the comma-separated list */
1241        do {
1242                unsigned long long start, end = ULLONG_MAX, size;
1243
1244                /* get the start of the range */
1245                start = memparse(cur, &tmp);
1246                if (cur == tmp) {
1247                        pr_warning("crashkernel: Memory value expected\n");
1248                        return -EINVAL;
1249                }
1250                cur = tmp;
1251                if (*cur != '-') {
1252                        pr_warning("crashkernel: '-' expected\n");
1253                        return -EINVAL;
1254                }
1255                cur++;
1256
1257                /* if no ':' is here, than we read the end */
1258                if (*cur != ':') {
1259                        end = memparse(cur, &tmp);
1260                        if (cur == tmp) {
1261                                pr_warning("crashkernel: Memory "
1262                                                "value expected\n");
1263                                return -EINVAL;
1264                        }
1265                        cur = tmp;
1266                        if (end <= start) {
1267                                pr_warning("crashkernel: end <= start\n");
1268                                return -EINVAL;
1269                        }
1270                }
1271
1272                if (*cur != ':') {
1273                        pr_warning("crashkernel: ':' expected\n");
1274                        return -EINVAL;
1275                }
1276                cur++;
1277
1278                size = memparse(cur, &tmp);
1279                if (cur == tmp) {
1280                        pr_warning("Memory value expected\n");
1281                        return -EINVAL;
1282                }
1283                cur = tmp;
1284                if (size >= system_ram) {
1285                        pr_warning("crashkernel: invalid size\n");
1286                        return -EINVAL;
1287                }
1288
1289                /* match ? */
1290                if (system_ram >= start && system_ram < end) {
1291                        *crash_size = size;
1292                        break;
1293                }
1294        } while (*cur++ == ',');
1295
1296        if (*crash_size > 0) {
1297                while (*cur && *cur != ' ' && *cur != '@')
1298                        cur++;
1299                if (*cur == '@') {
1300                        cur++;
1301                        *crash_base = memparse(cur, &tmp);
1302                        if (cur == tmp) {
1303                                pr_warning("Memory value expected "
1304                                                "after '@'\n");
1305                                return -EINVAL;
1306                        }
1307                }
1308        }
1309
1310        return 0;
1311}
1312
1313/*
1314 * That function parses "simple" (old) crashkernel command lines like
1315 *
1316 *      crashkernel=size[@offset]
1317 *
1318 * It returns 0 on success and -EINVAL on failure.
1319 */
1320static int __init parse_crashkernel_simple(char                 *cmdline,
1321                                           unsigned long long   *crash_size,
1322                                           unsigned long long   *crash_base)
1323{
1324        char *cur = cmdline;
1325
1326        *crash_size = memparse(cmdline, &cur);
1327        if (cmdline == cur) {
1328                pr_warning("crashkernel: memory value expected\n");
1329                return -EINVAL;
1330        }
1331
1332        if (*cur == '@')
1333                *crash_base = memparse(cur+1, &cur);
1334
1335        return 0;
1336}
1337
1338/*
1339 * That function is the entry point for command line parsing and should be
1340 * called from the arch-specific code.
1341 */
1342int __init parse_crashkernel(char                *cmdline,
1343                             unsigned long long system_ram,
1344                             unsigned long long *crash_size,
1345                             unsigned long long *crash_base)
1346{
1347        char    *p = cmdline, *ck_cmdline = NULL;
1348        char    *first_colon, *first_space;
1349
1350        BUG_ON(!crash_size || !crash_base);
1351        *crash_size = 0;
1352        *crash_base = 0;
1353
1354        /* find crashkernel and use the last one if there are more */
1355        p = strstr(p, "crashkernel=");
1356        while (p) {
1357                ck_cmdline = p;
1358                p = strstr(p+1, "crashkernel=");
1359        }
1360
1361        if (!ck_cmdline)
1362                return -EINVAL;
1363
1364        ck_cmdline += 12; /* strlen("crashkernel=") */
1365
1366        /*
1367         * if the commandline contains a ':', then that's the extended
1368         * syntax -- if not, it must be the classic syntax
1369         */
1370        first_colon = strchr(ck_cmdline, ':');
1371        first_space = strchr(ck_cmdline, ' ');
1372        if (first_colon && (!first_space || first_colon < first_space))
1373                return parse_crashkernel_mem(ck_cmdline, system_ram,
1374                                crash_size, crash_base);
1375        else
1376                return parse_crashkernel_simple(ck_cmdline, crash_size,
1377                                crash_base);
1378
1379        return 0;
1380}
1381
1382
1383
1384void crash_save_vmcoreinfo(void)
1385{
1386        u32 *buf;
1387
1388        if (!vmcoreinfo_size)
1389                return;
1390
1391        vmcoreinfo_append_str("CRASHTIME=%ld", get_seconds());
1392
1393        buf = (u32 *)vmcoreinfo_note;
1394
1395        buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
1396                              vmcoreinfo_size);
1397
1398        final_note(buf);
1399}
1400
1401void vmcoreinfo_append_str(const char *fmt, ...)
1402{
1403        va_list args;
1404        char buf[0x50];
1405        int r;
1406
1407        va_start(args, fmt);
1408        r = vsnprintf(buf, sizeof(buf), fmt, args);
1409        va_end(args);
1410
1411        if (r + vmcoreinfo_size > vmcoreinfo_max_size)
1412                r = vmcoreinfo_max_size - vmcoreinfo_size;
1413
1414        memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
1415
1416        vmcoreinfo_size += r;
1417}
1418
1419/*
1420 * provide an empty default implementation here -- architecture
1421 * code may override this
1422 */
1423void __attribute__ ((weak)) arch_crash_save_vmcoreinfo(void)
1424{}
1425
1426unsigned long __attribute__ ((weak)) paddr_vmcoreinfo_note(void)
1427{
1428        return __pa((unsigned long)(char *)&vmcoreinfo_note);
1429}
1430
1431static int __init crash_save_vmcoreinfo_init(void)
1432{
1433        VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
1434        VMCOREINFO_PAGESIZE(PAGE_SIZE);
1435
1436        VMCOREINFO_SYMBOL(init_uts_ns);
1437        VMCOREINFO_SYMBOL(node_online_map);
1438        VMCOREINFO_SYMBOL(swapper_pg_dir);
1439        VMCOREINFO_SYMBOL(_stext);
1440        VMCOREINFO_SYMBOL(vmlist);
1441
1442#ifndef CONFIG_NEED_MULTIPLE_NODES
1443        VMCOREINFO_SYMBOL(mem_map);
1444        VMCOREINFO_SYMBOL(contig_page_data);
1445#endif
1446#ifdef CONFIG_SPARSEMEM
1447        VMCOREINFO_SYMBOL(mem_section);
1448        VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
1449        VMCOREINFO_STRUCT_SIZE(mem_section);
1450        VMCOREINFO_OFFSET(mem_section, section_mem_map);
1451#endif
1452        VMCOREINFO_STRUCT_SIZE(page);
1453        VMCOREINFO_STRUCT_SIZE(pglist_data);
1454        VMCOREINFO_STRUCT_SIZE(zone);
1455        VMCOREINFO_STRUCT_SIZE(free_area);
1456        VMCOREINFO_STRUCT_SIZE(list_head);
1457        VMCOREINFO_SIZE(nodemask_t);
1458        VMCOREINFO_OFFSET(page, flags);
1459        VMCOREINFO_OFFSET(page, _count);
1460        VMCOREINFO_OFFSET(page, mapping);
1461        VMCOREINFO_OFFSET(page, lru);
1462        VMCOREINFO_OFFSET(pglist_data, node_zones);
1463        VMCOREINFO_OFFSET(pglist_data, nr_zones);
1464#ifdef CONFIG_FLAT_NODE_MEM_MAP
1465        VMCOREINFO_OFFSET(pglist_data, node_mem_map);
1466#endif
1467        VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
1468        VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
1469        VMCOREINFO_OFFSET(pglist_data, node_id);
1470        VMCOREINFO_OFFSET(zone, free_area);
1471        VMCOREINFO_OFFSET(zone, vm_stat);
1472        VMCOREINFO_OFFSET(zone, spanned_pages);
1473        VMCOREINFO_OFFSET(free_area, free_list);
1474        VMCOREINFO_OFFSET(list_head, next);
1475        VMCOREINFO_OFFSET(list_head, prev);
1476        VMCOREINFO_OFFSET(vm_struct, addr);
1477        VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
1478        log_buf_kexec_setup();
1479        VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
1480        VMCOREINFO_NUMBER(NR_FREE_PAGES);
1481        VMCOREINFO_NUMBER(PG_lru);
1482        VMCOREINFO_NUMBER(PG_private);
1483        VMCOREINFO_NUMBER(PG_swapcache);
1484
1485        arch_crash_save_vmcoreinfo();
1486
1487        return 0;
1488}
1489
1490module_init(crash_save_vmcoreinfo_init)
1491
1492/*
1493 * Move into place and start executing a preloaded standalone
1494 * executable.  If nothing was preloaded return an error.
1495 */
1496int kernel_kexec(void)
1497{
1498        int error = 0;
1499
1500        if (!mutex_trylock(&kexec_mutex))
1501                return -EBUSY;
1502        if (!kexec_image) {
1503                error = -EINVAL;
1504                goto Unlock;
1505        }
1506
1507#ifdef CONFIG_KEXEC_JUMP
1508        if (kexec_image->preserve_context) {
1509                mutex_lock(&pm_mutex);
1510                pm_prepare_console();
1511                error = freeze_processes();
1512                if (error) {
1513                        error = -EBUSY;
1514                        goto Restore_console;
1515                }
1516                suspend_console();
1517                error = dpm_suspend_start(PMSG_FREEZE);
1518                if (error)
1519                        goto Resume_console;
1520                /* At this point, dpm_suspend_start() has been called,
1521                 * but *not* dpm_suspend_noirq(). We *must* call
1522                 * dpm_suspend_noirq() now.  Otherwise, drivers for
1523                 * some devices (e.g. interrupt controllers) become
1524                 * desynchronized with the actual state of the
1525                 * hardware at resume time, and evil weirdness ensues.
1526                 */
1527                error = dpm_suspend_noirq(PMSG_FREEZE);
1528                if (error)
1529                        goto Resume_devices;
1530                error = disable_nonboot_cpus();
1531                if (error)
1532                        goto Enable_cpus;
1533                local_irq_disable();
1534                error = syscore_suspend();
1535                if (error)
1536                        goto Enable_irqs;
1537        } else
1538#endif
1539        {
1540                kernel_restart_prepare(NULL);
1541                printk(KERN_EMERG "Starting new kernel\n");
1542                machine_shutdown();
1543        }
1544
1545        machine_kexec(kexec_image);
1546
1547#ifdef CONFIG_KEXEC_JUMP
1548        if (kexec_image->preserve_context) {
1549                syscore_resume();
1550 Enable_irqs:
1551                local_irq_enable();
1552 Enable_cpus:
1553                enable_nonboot_cpus();
1554                dpm_resume_noirq(PMSG_RESTORE);
1555 Resume_devices:
1556                dpm_resume_end(PMSG_RESTORE);
1557 Resume_console:
1558                resume_console();
1559                thaw_processes();
1560 Restore_console:
1561                pm_restore_console();
1562                mutex_unlock(&pm_mutex);
1563        }
1564#endif
1565
1566 Unlock:
1567        mutex_unlock(&kexec_mutex);
1568        return error;
1569}
1570
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