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 <linux/utsname.h>
  25#include <linux/numa.h>
  26#include <linux/suspend.h>
  27#include <linux/device.h>
  28#include <linux/freezer.h>
  29#include <linux/pm.h>
  30#include <linux/cpu.h>
  31#include <linux/console.h>
  32#include <linux/vmalloc.h>
  33#include <linux/swap.h>
  34#include <linux/syscore_ops.h>
  35
  36#include <asm/page.h>
  37#include <asm/uaccess.h>
  38#include <asm/io.h>
  39#include <asm/sections.h>
  40
  41/* Per cpu memory for storing cpu states in case of system crash. */
  42note_buf_t __percpu *crash_notes;
  43
  44/* vmcoreinfo stuff */
  45static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
  46u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
  47size_t vmcoreinfo_size;
  48size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
  49
  50/* Location of the reserved area for the crash kernel */
  51struct resource crashk_res = {
  52        .name  = "Crash kernel",
  53        .start = 0,
  54        .end   = 0,
  55        .flags = IORESOURCE_BUSY | IORESOURCE_MEM
  56};
  57
  58int kexec_should_crash(struct task_struct *p)
  59{
  60        if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)
  61                return 1;
  62        return 0;
  63}
  64
  65/*
  66 * When kexec transitions to the new kernel there is a one-to-one
  67 * mapping between physical and virtual addresses.  On processors
  68 * where you can disable the MMU this is trivial, and easy.  For
  69 * others it is still a simple predictable page table to setup.
  70 *
  71 * In that environment kexec copies the new kernel to its final
  72 * resting place.  This means I can only support memory whose
  73 * physical address can fit in an unsigned long.  In particular
  74 * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
  75 * If the assembly stub has more restrictive requirements
  76 * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
  77 * defined more restrictively in <asm/kexec.h>.
  78 *
  79 * The code for the transition from the current kernel to the
  80 * the new kernel is placed in the control_code_buffer, whose size
  81 * is given by KEXEC_CONTROL_PAGE_SIZE.  In the best case only a single
  82 * page of memory is necessary, but some architectures require more.
  83 * Because this memory must be identity mapped in the transition from
  84 * virtual to physical addresses it must live in the range
  85 * 0 - TASK_SIZE, as only the user space mappings are arbitrarily
  86 * modifiable.
  87 *
  88 * The assembly stub in the control code buffer is passed a linked list
  89 * of descriptor pages detailing the source pages of the new kernel,
  90 * and the destination addresses of those source pages.  As this data
  91 * structure is not used in the context of the current OS, it must
  92 * be self-contained.
  93 *
  94 * The code has been made to work with highmem pages and will use a
  95 * destination page in its final resting place (if it happens
  96 * to allocate it).  The end product of this is that most of the
  97 * physical address space, and most of RAM can be used.
  98 *
  99 * Future directions include:
 100 *  - allocating a page table with the control code buffer identity
 101 *    mapped, to simplify machine_kexec and make kexec_on_panic more
 102 *    reliable.
 103 */
 104
 105/*
 106 * KIMAGE_NO_DEST is an impossible destination address..., for
 107 * allocating pages whose destination address we do not care about.
 108 */
 109#define KIMAGE_NO_DEST (-1UL)
 110
 111static int kimage_is_destination_range(struct kimage *image,
 112                                       unsigned long start, unsigned long end);
 113static struct page *kimage_alloc_page(struct kimage *image,
 114                                       gfp_t gfp_mask,
 115                                       unsigned long dest);
 116
 117static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
 118                            unsigned long nr_segments,
 119                            struct kexec_segment __user *segments)
 120{
 121        size_t segment_bytes;
 122        struct kimage *image;
 123        unsigned long i;
 124        int result;
 125
 126        /* Allocate a controlling structure */
 127        result = -ENOMEM;
 128        image = kzalloc(sizeof(*image), GFP_KERNEL);
 129        if (!image)
 130                goto out;
 131
 132        image->head = 0;
 133        image->entry = &image->head;
 134        image->last_entry = &image->head;
 135        image->control_page = ~0; /* By default this does not apply */
 136        image->start = entry;
 137        image->type = KEXEC_TYPE_DEFAULT;
 138
 139        /* Initialize the list of control pages */
 140        INIT_LIST_HEAD(&image->control_pages);
 141
 142        /* Initialize the list of destination pages */
 143        INIT_LIST_HEAD(&image->dest_pages);
 144
 145        /* Initialize the list of unusable pages */
 146        INIT_LIST_HEAD(&image->unuseable_pages);
 147
 148        /* Read in the segments */
 149        image->nr_segments = nr_segments;
 150        segment_bytes = nr_segments * sizeof(*segments);
 151        result = copy_from_user(image->segment, segments, segment_bytes);
 152        if (result) {
 153                result = -EFAULT;
 154                goto out;
 155        }
 156
 157        /*
 158         * Verify we have good destination addresses.  The caller is
 159         * responsible for making certain we don't attempt to load
 160         * the new image into invalid or reserved areas of RAM.  This
 161         * just verifies it is an address we can use.
 162         *
 163         * Since the kernel does everything in page size chunks ensure
 164         * the destination addresses are page aligned.  Too many
 165         * special cases crop of when we don't do this.  The most
 166         * insidious is getting overlapping destination addresses
 167         * simply because addresses are changed to page size
 168         * granularity.
 169         */
 170        result = -EADDRNOTAVAIL;
 171        for (i = 0; i < nr_segments; i++) {
 172                unsigned long mstart, mend;
 173
 174                mstart = image->segment[i].mem;
 175                mend   = mstart + image->segment[i].memsz;
 176                if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
 177                        goto out;
 178                if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
 179                        goto out;
 180        }
 181
 182        /* Verify our destination addresses do not overlap.
 183         * If we alloed overlapping destination addresses
 184         * through very weird things can happen with no
 185         * easy explanation as one segment stops on another.
 186         */
 187        result = -EINVAL;
 188        for (i = 0; i < nr_segments; i++) {
 189                unsigned long mstart, mend;
 190                unsigned long j;
 191
 192                mstart = image->segment[i].mem;
 193                mend   = mstart + image->segment[i].memsz;
 194                for (j = 0; j < i; j++) {
 195                        unsigned long pstart, pend;
 196                        pstart = image->segment[j].mem;
 197                        pend   = pstart + image->segment[j].memsz;
 198                        /* Do the segments overlap ? */
 199                        if ((mend > pstart) && (mstart < pend))
 200                                goto out;
 201                }
 202        }
 203
 204        /* Ensure our buffer sizes are strictly less than
 205         * our memory sizes.  This should always be the case,
 206         * and it is easier to check up front than to be surprised
 207         * later on.
 208         */
 209        result = -EINVAL;
 210        for (i = 0; i < nr_segments; i++) {
 211                if (image->segment[i].bufsz > image->segment[i].memsz)
 212                        goto out;
 213        }
 214
 215        result = 0;
 216out:
 217        if (result == 0)
 218                *rimage = image;
 219        else
 220                kfree(image);
 221
 222        return result;
 223
 224}
 225
 226static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
 227                                unsigned long nr_segments,
 228                                struct kexec_segment __user *segments)
 229{
 230        int result;
 231        struct kimage *image;
 232
 233        /* Allocate and initialize a controlling structure */
 234        image = NULL;
 235        result = do_kimage_alloc(&image, entry, nr_segments, segments);
 236        if (result)
 237                goto out;
 238
 239        *rimage = image;
 240
 241        /*
 242         * Find a location for the control code buffer, and add it
 243         * the vector of segments so that it's pages will also be
 244         * counted as destination pages.
 245         */
 246        result = -ENOMEM;
 247        image->control_code_page = kimage_alloc_control_pages(image,
 248                                           get_order(KEXEC_CONTROL_PAGE_SIZE));
 249        if (!image->control_code_page) {
 250                printk(KERN_ERR "Could not allocate control_code_buffer\n");
 251                goto out;
 252        }
 253
 254        image->swap_page = kimage_alloc_control_pages(image, 0);
 255        if (!image->swap_page) {
 256                printk(KERN_ERR "Could not allocate swap buffer\n");
 257                goto out;
 258        }
 259
 260        result = 0;
 261 out:
 262        if (result == 0)
 263                *rimage = image;
 264        else
 265                kfree(image);
 266
 267        return result;
 268}
 269
 270static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
 271                                unsigned long nr_segments,
 272                                struct kexec_segment __user *segments)
 273{
 274        int result;
 275        struct kimage *image;
 276        unsigned long i;
 277
 278        image = NULL;
 279        /* Verify we have a valid entry point */
 280        if ((entry < crashk_res.start) || (entry > crashk_res.end)) {
 281                result = -EADDRNOTAVAIL;
 282                goto out;
 283        }
 284
 285        /* Allocate and initialize a controlling structure */
 286        result = do_kimage_alloc(&image, entry, nr_segments, segments);
 287        if (result)
 288                goto out;
 289
 290        /* Enable the special crash kernel control page
 291         * allocation policy.
 292         */
 293        image->control_page = crashk_res.start;
 294        image->type = KEXEC_TYPE_CRASH;
 295
 296        /*
 297         * Verify we have good destination addresses.  Normally
 298         * the caller is responsible for making certain we don't
 299         * attempt to load the new image into invalid or reserved
 300         * areas of RAM.  But crash kernels are preloaded into a
 301         * reserved area of ram.  We must ensure the addresses
 302         * are in the reserved area otherwise preloading the
 303         * kernel could corrupt things.
 304         */
 305        result = -EADDRNOTAVAIL;
 306        for (i = 0; i < nr_segments; i++) {
 307                unsigned long mstart, mend;
 308
 309                mstart = image->segment[i].mem;
 310                mend = mstart + image->segment[i].memsz - 1;
 311                /* Ensure we are within the crash kernel limits */
 312                if ((mstart < crashk_res.start) || (mend > crashk_res.end))
 313                        goto out;
 314        }
 315
 316        /*
 317         * Find a location for the control code buffer, and add
 318         * the vector of segments so that it's pages will also be
 319         * counted as destination pages.
 320         */
 321        result = -ENOMEM;
 322        image->control_code_page = kimage_alloc_control_pages(image,
 323                                           get_order(KEXEC_CONTROL_PAGE_SIZE));
 324        if (!image->control_code_page) {
 325                printk(KERN_ERR "Could not allocate control_code_buffer\n");
 326                goto out;
 327        }
 328
 329        result = 0;
 330out:
 331        if (result == 0)
 332                *rimage = image;
 333        else
 334                kfree(image);
 335
 336        return result;
 337}
 338
 339static int kimage_is_destination_range(struct kimage *image,
 340                                        unsigned long start,
 341                                        unsigned long end)
 342{
 343        unsigned long i;
 344
 345        for (i = 0; i < image->nr_segments; i++) {
 346                unsigned long mstart, mend;
 347
 348                mstart = image->segment[i].mem;
 349                mend = mstart + image->segment[i].memsz;
 350                if ((end > mstart) && (start < mend))
 351                        return 1;
 352        }
 353
 354        return 0;
 355}
 356
 357static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
 358{
 359        struct page *pages;
 360
 361        pages = alloc_pages(gfp_mask, order);
 362        if (pages) {
 363                unsigned int count, i;
 364                pages->mapping = NULL;
 365                set_page_private(pages, order);
 366                count = 1 << order;
 367                for (i = 0; i < count; i++)
 368                        SetPageReserved(pages + i);
 369        }
 370
 371        return pages;
 372}
 373
 374static void kimage_free_pages(struct page *page)
 375{
 376        unsigned int order, count, i;
 377
 378        order = page_private(page);
 379        count = 1 << order;
 380        for (i = 0; i < count; i++)
 381                ClearPageReserved(page + i);
 382        __free_pages(page, order);
 383}
 384
 385static void kimage_free_page_list(struct list_head *list)
 386{
 387        struct list_head *pos, *next;
 388
 389        list_for_each_safe(pos, next, list) {
 390                struct page *page;
 391
 392                page = list_entry(pos, struct page, lru);
 393                list_del(&page->lru);
 394                kimage_free_pages(page);
 395        }
 396}
 397
 398static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
 399                                                        unsigned int order)
 400{
 401        /* Control pages are special, they are the intermediaries
 402         * that are needed while we copy the rest of the pages
 403         * to their final resting place.  As such they must
 404         * not conflict with either the destination addresses
 405         * or memory the kernel is already using.
 406         *
 407         * The only case where we really need more than one of
 408         * these are for architectures where we cannot disable
 409         * the MMU and must instead generate an identity mapped
 410         * page table for all of the memory.
 411         *
 412         * At worst this runs in O(N) of the image size.
 413         */
 414        struct list_head extra_pages;
 415        struct page *pages;
 416        unsigned int count;
 417
 418        count = 1 << order;
 419        INIT_LIST_HEAD(&extra_pages);
 420
 421        /* Loop while I can allocate a page and the page allocated
 422         * is a destination page.
 423         */
 424        do {
 425                unsigned long pfn, epfn, addr, eaddr;
 426
 427                pages = kimage_alloc_pages(GFP_KERNEL, order);
 428                if (!pages)
 429                        break;
 430                pfn   = page_to_pfn(pages);
 431                epfn  = pfn + count;
 432                addr  = pfn << PAGE_SHIFT;
 433                eaddr = epfn << PAGE_SHIFT;
 434                if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
 435                              kimage_is_destination_range(image, addr, eaddr)) {
 436                        list_add(&pages->lru, &extra_pages);
 437                        pages = NULL;
 438                }
 439        } while (!pages);
 440
 441        if (pages) {
 442                /* Remember the allocated page... */
 443                list_add(&pages->lru, &image->control_pages);
 444
 445                /* Because the page is already in it's destination
 446                 * location we will never allocate another page at
 447                 * that address.  Therefore kimage_alloc_pages
 448                 * will not return it (again) and we don't need
 449                 * to give it an entry in image->segment[].
 450                 */
 451        }
 452        /* Deal with the destination pages I have inadvertently allocated.
 453         *
 454         * Ideally I would convert multi-page allocations into single
 455         * page allocations, and add everything to image->dest_pages.
 456         *
 457         * For now it is simpler to just free the pages.
 458         */
 459        kimage_free_page_list(&extra_pages);
 460
 461        return pages;
 462}
 463
 464static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
 465                                                      unsigned int order)
 466{
 467        /* Control pages are special, they are the intermediaries
 468         * that are needed while we copy the rest of the pages
 469         * to their final resting place.  As such they must
 470         * not conflict with either the destination addresses
 471         * or memory the kernel is already using.
 472         *
 473         * Control pages are also the only pags we must allocate
 474         * when loading a crash kernel.  All of the other pages
 475         * are specified by the segments and we just memcpy
 476         * into them directly.
 477         *
 478         * The only case where we really need more than one of
 479         * these are for architectures where we cannot disable
 480         * the MMU and must instead generate an identity mapped
 481         * page table for all of the memory.
 482         *
 483         * Given the low demand this implements a very simple
 484         * allocator that finds the first hole of the appropriate
 485         * size in the reserved memory region, and allocates all
 486         * of the memory up to and including the hole.
 487         */
 488        unsigned long hole_start, hole_end, size;
 489        struct page *pages;
 490
 491        pages = NULL;
 492        size = (1 << order) << PAGE_SHIFT;
 493        hole_start = (image->control_page + (size - 1)) & ~(size - 1);
 494        hole_end   = hole_start + size - 1;
 495        while (hole_end <= crashk_res.end) {
 496                unsigned long i;
 497
 498                if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
 499                        break;
 500                if (hole_end > crashk_res.end)
 501                        break;
 502                /* See if I overlap any of the segments */
 503                for (i = 0; i < image->nr_segments; i++) {
 504                        unsigned long mstart, mend;
 505
 506                        mstart = image->segment[i].mem;
 507                        mend   = mstart + image->segment[i].memsz - 1;
 508                        if ((hole_end >= mstart) && (hole_start <= mend)) {
 509                                /* Advance the hole to the end of the segment */
 510                                hole_start = (mend + (size - 1)) & ~(size - 1);
 511                                hole_end   = hole_start + size - 1;
 512                                break;
 513                        }
 514                }
 515                /* If I don't overlap any segments I have found my hole! */
 516                if (i == image->nr_segments) {
 517                        pages = pfn_to_page(hole_start >> PAGE_SHIFT);
 518                        break;
 519                }
 520        }
 521        if (pages)
 522                image->control_page = hole_end;
 523
 524        return pages;
 525}
 526
 527
 528struct page *kimage_alloc_control_pages(struct kimage *image,
 529                                         unsigned int order)
 530{
 531        struct page *pages = NULL;
 532
 533        switch (image->type) {
 534        case KEXEC_TYPE_DEFAULT:
 535                pages = kimage_alloc_normal_control_pages(image, order);
 536                break;
 537        case KEXEC_TYPE_CRASH:
 538                pages = kimage_alloc_crash_control_pages(image, order);
 539                break;
 540        }
 541
 542        return pages;
 543}
 544
 545static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
 546{
 547        if (*image->entry != 0)
 548                image->entry++;
 549
 550        if (image->entry == image->last_entry) {
 551                kimage_entry_t *ind_page;
 552                struct page *page;
 553
 554                page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
 555                if (!page)
 556                        return -ENOMEM;
 557
 558                ind_page = page_address(page);
 559                *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
 560                image->entry = ind_page;
 561                image->last_entry = ind_page +
 562                                      ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
 563        }
 564        *image->entry = entry;
 565        image->entry++;
 566        *image->entry = 0;
 567
 568        return 0;
 569}
 570
 571static int kimage_set_destination(struct kimage *image,
 572                                   unsigned long destination)
 573{
 574        int result;
 575
 576        destination &= PAGE_MASK;
 577        result = kimage_add_entry(image, destination | IND_DESTINATION);
 578        if (result == 0)
 579                image->destination = destination;
 580
 581        return result;
 582}
 583
 584
 585static int kimage_add_page(struct kimage *image, unsigned long page)
 586{
 587        int result;
 588
 589        page &= PAGE_MASK;
 590        result = kimage_add_entry(image, page | IND_SOURCE);
 591        if (result == 0)
 592                image->destination += PAGE_SIZE;
 593
 594        return result;
 595}
 596
 597
 598static void kimage_free_extra_pages(struct kimage *image)
 599{
 600        /* Walk through and free any extra destination pages I may have */
 601        kimage_free_page_list(&image->dest_pages);
 602
 603        /* Walk through and free any unusable pages I have cached */
 604        kimage_free_page_list(&image->unuseable_pages);
 605
 606}
 607static void kimage_terminate(struct kimage *image)
 608{
 609        if (*image->entry != 0)
 610                image->entry++;
 611
 612        *image->entry = IND_DONE;
 613}
 614
 615#define for_each_kimage_entry(image, ptr, entry) \
 616        for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
 617                ptr = (entry & IND_INDIRECTION)? \
 618                        phys_to_virt((entry & PAGE_MASK)): ptr +1)
 619
 620static void kimage_free_entry(kimage_entry_t entry)
 621{
 622        struct page *page;
 623
 624        page = pfn_to_page(entry >> PAGE_SHIFT);
 625        kimage_free_pages(page);
 626}
 627
 628static void kimage_free(struct kimage *image)
 629{
 630        kimage_entry_t *ptr, entry;
 631        kimage_entry_t ind = 0;
 632
 633        if (!image)
 634                return;
 635
 636        kimage_free_extra_pages(image);
 637        for_each_kimage_entry(image, ptr, entry) {
 638                if (entry & IND_INDIRECTION) {
 639                        /* Free the previous indirection page */
 640                        if (ind & IND_INDIRECTION)
 641                                kimage_free_entry(ind);
 642                        /* Save this indirection page until we are
 643                         * done with it.
 644                         */
 645                        ind = entry;
 646                }
 647                else if (entry & IND_SOURCE)
 648                        kimage_free_entry(entry);
 649        }
 650        /* Free the final indirection page */
 651        if (ind & IND_INDIRECTION)
 652                kimage_free_entry(ind);
 653
 654        /* Handle any machine specific cleanup */
 655        machine_kexec_cleanup(image);
 656
 657        /* Free the kexec control pages... */
 658        kimage_free_page_list(&image->control_pages);
 659        kfree(image);
 660}
 661
 662static kimage_entry_t *kimage_dst_used(struct kimage *image,
 663                                        unsigned long page)
 664{
 665        kimage_entry_t *ptr, entry;
 666        unsigned long destination = 0;
 667
 668        for_each_kimage_entry(image, ptr, entry) {
 669                if (entry & IND_DESTINATION)
 670                        destination = entry & PAGE_MASK;
 671                else if (entry & IND_SOURCE) {
 672                        if (page == destination)
 673                                return ptr;
 674                        destination += PAGE_SIZE;
 675                }
 676        }
 677
 678        return NULL;
 679}
 680
 681static struct page *kimage_alloc_page(struct kimage *image,
 682                                        gfp_t gfp_mask,
 683                                        unsigned long destination)
 684{
 685        /*
 686         * Here we implement safeguards to ensure that a source page
 687         * is not copied to its destination page before the data on
 688         * the destination page is no longer useful.
 689         *
 690         * To do this we maintain the invariant that a source page is
 691         * either its own destination page, or it is not a
 692         * destination page at all.
 693         *
 694         * That is slightly stronger than required, but the proof
 695         * that no problems will not occur is trivial, and the
 696         * implementation is simply to verify.
 697         *
 698         * When allocating all pages normally this algorithm will run
 699         * in O(N) time, but in the worst case it will run in O(N^2)
 700         * time.   If the runtime is a problem the data structures can
 701         * be fixed.
 702         */
 703        struct page *page;
 704        unsigned long addr;
 705
 706        /*
 707         * Walk through the list of destination pages, and see if I
 708         * have a match.
 709         */
 710        list_for_each_entry(page, &image->dest_pages, lru) {
 711                addr = page_to_pfn(page) << PAGE_SHIFT;
 712                if (addr == destination) {
 713                        list_del(&page->lru);
 714                        return page;
 715                }
 716        }
 717        page = NULL;
 718        while (1) {
 719                kimage_entry_t *old;
 720
 721                /* Allocate a page, if we run out of memory give up */
 722                page = kimage_alloc_pages(gfp_mask, 0);
 723                if (!page)
 724                        return NULL;
 725                /* If the page cannot be used file it away */
 726                if (page_to_pfn(page) >
 727                                (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
 728                        list_add(&page->lru, &image->unuseable_pages);
 729                        continue;
 730                }
 731                addr = page_to_pfn(page) << PAGE_SHIFT;
 732
 733                /* If it is the destination page we want use it */
 734                if (addr == destination)
 735                        break;
 736
 737                /* If the page is not a destination page use it */
 738                if (!kimage_is_destination_range(image, addr,
 739                                                  addr + PAGE_SIZE))
 740                        break;
 741
 742                /*
 743                 * I know that the page is someones destination page.
 744                 * See if there is already a source page for this
 745                 * destination page.  And if so swap the source pages.
 746                 */
 747                old = kimage_dst_used(image, addr);
 748                if (old) {
 749                        /* If so move it */
 750                        unsigned long old_addr;
 751                        struct page *old_page;
 752
 753                        old_addr = *old & PAGE_MASK;
 754                        old_page = pfn_to_page(old_addr >> PAGE_SHIFT);
 755                        copy_highpage(page, old_page);
 756                        *old = addr | (*old & ~PAGE_MASK);
 757
 758                        /* The old page I have found cannot be a
 759                         * destination page, so return it if it's
 760                         * gfp_flags honor the ones passed in.
 761                         */
 762                        if (!(gfp_mask & __GFP_HIGHMEM) &&
 763                            PageHighMem(old_page)) {
 764                                kimage_free_pages(old_page);
 765                                continue;
 766                        }
 767                        addr = old_addr;
 768                        page = old_page;
 769                        break;
 770                }
 771                else {
 772                        /* Place the page on the destination list I
 773                         * will use it later.
 774                         */
 775                        list_add(&page->lru, &image->dest_pages);
 776                }
 777        }
 778
 779        return page;
 780}
 781
 782static int kimage_load_normal_segment(struct kimage *image,
 783                                         struct kexec_segment *segment)
 784{
 785        unsigned long maddr;
 786        unsigned long ubytes, mbytes;
 787        int result;
 788        unsigned char __user *buf;
 789
 790        result = 0;
 791        buf = segment->buf;
 792        ubytes = segment->bufsz;
 793        mbytes = segment->memsz;
 794        maddr = segment->mem;
 795
 796        result = kimage_set_destination(image, maddr);
 797        if (result < 0)
 798                goto out;
 799
 800        while (mbytes) {
 801                struct page *page;
 802                char *ptr;
 803                size_t uchunk, mchunk;
 804
 805                page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
 806                if (!page) {
 807                        result  = -ENOMEM;
 808                        goto out;
 809                }
 810                result = kimage_add_page(image, page_to_pfn(page)
 811                                                                << PAGE_SHIFT);
 812                if (result < 0)
 813                        goto out;
 814
 815                ptr = kmap(page);
 816                /* Start with a clear page */
 817                clear_page(ptr);
 818                ptr += maddr & ~PAGE_MASK;
 819                mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
 820                if (mchunk > mbytes)
 821                        mchunk = mbytes;
 822
 823                uchunk = mchunk;
 824                if (uchunk > ubytes)
 825                        uchunk = ubytes;
 826
 827                result = copy_from_user(ptr, buf, uchunk);
 828                kunmap(page);
 829                if (result) {
 830                        result = -EFAULT;
 831                        goto out;
 832                }
 833                ubytes -= uchunk;
 834                maddr  += mchunk;
 835                buf    += mchunk;
 836                mbytes -= mchunk;
 837        }
 838out:
 839        return result;
 840}
 841
 842static int kimage_load_crash_segment(struct kimage *image,
 843                                        struct kexec_segment *segment)
 844{
 845        /* For crash dumps kernels we simply copy the data from
 846         * user space to it's destination.
 847         * We do things a page at a time for the sake of kmap.
 848         */
 849        unsigned long maddr;
 850        unsigned long ubytes, mbytes;
 851        int result;
 852        unsigned char __user *buf;
 853
 854        result = 0;
 855        buf = segment->buf;
 856        ubytes = segment->bufsz;
 857        mbytes = segment->memsz;
 858        maddr = segment->mem;
 859        while (mbytes) {
 860                struct page *page;
 861                char *ptr;
 862                size_t uchunk, mchunk;
 863
 864                page = pfn_to_page(maddr >> PAGE_SHIFT);
 865                if (!page) {
 866                        result  = -ENOMEM;
 867                        goto out;
 868                }
 869                ptr = kmap(page);
 870                ptr += maddr & ~PAGE_MASK;
 871                mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
 872                if (mchunk > mbytes)
 873                        mchunk = mbytes;
 874
 875                uchunk = mchunk;
 876                if (uchunk > ubytes) {
 877                        uchunk = ubytes;
 878                        /* Zero the trailing part of the page */
 879                        memset(ptr + uchunk, 0, mchunk - uchunk);
 880                }
 881                result = copy_from_user(ptr, buf, uchunk);
 882                kexec_flush_icache_page(page);
 883                kunmap(page);
 884                if (result) {
 885                        result = -EFAULT;
 886                        goto out;
 887                }
 888                ubytes -= uchunk;
 889                maddr  += mchunk;
 890                buf    += mchunk;
 891                mbytes -= mchunk;
 892        }
 893out:
 894        return result;
 895}
 896
 897static int kimage_load_segment(struct kimage *image,
 898                                struct kexec_segment *segment)
 899{
 900        int result = -ENOMEM;
 901
 902        switch (image->type) {
 903        case KEXEC_TYPE_DEFAULT:
 904                result = kimage_load_normal_segment(image, segment);
 905                break;
 906        case KEXEC_TYPE_CRASH:
 907                result = kimage_load_crash_segment(image, segment);
 908                break;
 909        }
 910
 911        return result;
 912}
 913
 914/*
 915 * Exec Kernel system call: for obvious reasons only root may call it.
 916 *
 917 * This call breaks up into three pieces.
 918 * - A generic part which loads the new kernel from the current
 919 *   address space, and very carefully places the data in the
 920 *   allocated pages.
 921 *
 922 * - A generic part that interacts with the kernel and tells all of
 923 *   the devices to shut down.  Preventing on-going dmas, and placing
 924 *   the devices in a consistent state so a later kernel can
 925 *   reinitialize them.
 926 *
 927 * - A machine specific part that includes the syscall number
 928 *   and the copies the image to it's final destination.  And
 929 *   jumps into the image at entry.
 930 *
 931 * kexec does not sync, or unmount filesystems so if you need
 932 * that to happen you need to do that yourself.
 933 */
 934struct kimage *kexec_image;
 935struct kimage *kexec_crash_image;
 936
 937static DEFINE_MUTEX(kexec_mutex);
 938
 939SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
 940                struct kexec_segment __user *, segments, unsigned long, flags)
 941{
 942        struct kimage **dest_image, *image;
 943        int result;
 944
 945        /* We only trust the superuser with rebooting the system. */
 946        if (!capable(CAP_SYS_BOOT))
 947                return -EPERM;
 948
 949        /*
 950         * Verify we have a legal set of flags
 951         * This leaves us room for future extensions.
 952         */
 953        if ((flags & KEXEC_FLAGS) != (flags & ~KEXEC_ARCH_MASK))
 954                return -EINVAL;
 955
 956        /* Verify we are on the appropriate architecture */
 957        if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) &&
 958                ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
 959                return -EINVAL;
 960
 961        /* Put an artificial cap on the number
 962         * of segments passed to kexec_load.
 963         */
 964        if (nr_segments > KEXEC_SEGMENT_MAX)
 965                return -EINVAL;
 966
 967        image = NULL;
 968        result = 0;
 969
 970        /* Because we write directly to the reserved memory
 971         * region when loading crash kernels we need a mutex here to
 972         * prevent multiple crash  kernels from attempting to load
 973         * simultaneously, and to prevent a crash kernel from loading
 974         * over the top of a in use crash kernel.
 975         *
 976         * KISS: always take the mutex.
 977         */
 978        if (!mutex_trylock(&kexec_mutex))
 979                return -EBUSY;
 980
 981        dest_image = &kexec_image;
 982        if (flags & KEXEC_ON_CRASH)
 983                dest_image = &kexec_crash_image;
 984        if (nr_segments > 0) {
 985                unsigned long i;
 986
 987                /* Loading another kernel to reboot into */
 988                if ((flags & KEXEC_ON_CRASH) == 0)
 989                        result = kimage_normal_alloc(&image, entry,
 990                                                        nr_segments, segments);
 991                /* Loading another kernel to switch to if this one crashes */
 992                else if (flags & KEXEC_ON_CRASH) {
 993                        /* Free any current crash dump kernel before
 994                         * we corrupt it.
 995                         */
 996                        kimage_free(xchg(&kexec_crash_image, NULL));
 997                        result = kimage_crash_alloc(&image, entry,
 998                                                     nr_segments, segments);
 999                        crash_map_reserved_pages();
1000                }
1001                if (result)
1002                        goto out;
1003
1004                if (flags & KEXEC_PRESERVE_CONTEXT)
1005                        image->preserve_context = 1;
1006                result = machine_kexec_prepare(image);
1007                if (result)
1008                        goto out;
1009
1010                for (i = 0; i < nr_segments; i++) {
1011                        result = kimage_load_segment(image, &image->segment[i]);
1012                        if (result)
1013                                goto out;
1014                }
1015                kimage_terminate(image);
1016                if (flags & KEXEC_ON_CRASH)
1017                        crash_unmap_reserved_pages();
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/*
1030 * Add and remove page tables for crashkernel memory
1031 *
1032 * Provide an empty default implementation here -- architecture
1033 * code may override this
1034 */
1035void __weak crash_map_reserved_pages(void)
1036{}
1037
1038void __weak crash_unmap_reserved_pages(void)
1039{}
1040
1041#ifdef CONFIG_COMPAT
1042asmlinkage long compat_sys_kexec_load(unsigned long entry,
1043                                unsigned long nr_segments,
1044                                struct compat_kexec_segment __user *segments,
1045                                unsigned long flags)
1046{
1047        struct compat_kexec_segment in;
1048        struct kexec_segment out, __user *ksegments;
1049        unsigned long i, result;
1050
1051        /* Don't allow clients that don't understand the native
1052         * architecture to do anything.
1053         */
1054        if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
1055                return -EINVAL;
1056
1057        if (nr_segments > KEXEC_SEGMENT_MAX)
1058                return -EINVAL;
1059
1060        ksegments = compat_alloc_user_space(nr_segments * sizeof(out));
1061        for (i=0; i < nr_segments; i++) {
1062                result = copy_from_user(&in, &segments[i], sizeof(in));
1063                if (result)
1064                        return -EFAULT;
1065
1066                out.buf   = compat_ptr(in.buf);
1067                out.bufsz = in.bufsz;
1068                out.mem   = in.mem;
1069                out.memsz = in.memsz;
1070
1071                result = copy_to_user(&ksegments[i], &out, sizeof(out));
1072                if (result)
1073                        return -EFAULT;
1074        }
1075
1076        return sys_kexec_load(entry, nr_segments, ksegments, flags);
1077}
1078#endif
1079
1080void crash_kexec(struct pt_regs *regs)
1081{
1082        /* Take the kexec_mutex here to prevent sys_kexec_load
1083         * running on one cpu from replacing the crash kernel
1084         * we are using after a panic on a different cpu.
1085         *
1086         * If the crash kernel was not located in a fixed area
1087         * of memory the xchg(&kexec_crash_image) would be
1088         * sufficient.  But since I reuse the memory...
1089         */
1090        if (mutex_trylock(&kexec_mutex)) {
1091                if (kexec_crash_image) {
1092                        struct pt_regs fixed_regs;
1093
1094                        crash_setup_regs(&fixed_regs, regs);
1095                        crash_save_vmcoreinfo();
1096                        machine_crash_shutdown(&fixed_regs);
1097                        machine_kexec(kexec_crash_image);
1098                }
1099                mutex_unlock(&kexec_mutex);
1100        }
1101}
1102
1103size_t crash_get_memory_size(void)
1104{
1105        size_t size = 0;
1106        mutex_lock(&kexec_mutex);
1107        if (crashk_res.end != crashk_res.start)
1108                size = resource_size(&crashk_res);
1109        mutex_unlock(&kexec_mutex);
1110        return size;
1111}
1112
1113void __weak crash_free_reserved_phys_range(unsigned long begin,
1114                                           unsigned long end)
1115{
1116        unsigned long addr;
1117
1118        for (addr = begin; addr < end; addr += PAGE_SIZE) {
1119                ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
1120                init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
1121                free_page((unsigned long)__va(addr));
1122                totalram_pages++;
1123        }
1124}
1125
1126int crash_shrink_memory(unsigned long new_size)
1127{
1128        int ret = 0;
1129        unsigned long start, end;
1130        unsigned long old_size;
1131        struct resource *ram_res;
1132
1133        mutex_lock(&kexec_mutex);
1134
1135        if (kexec_crash_image) {
1136                ret = -ENOENT;
1137                goto unlock;
1138        }
1139        start = crashk_res.start;
1140        end = crashk_res.end;
1141        old_size = (end == 0) ? 0 : end - start + 1;
1142        if (new_size >= old_size) {
1143                ret = (new_size == old_size) ? 0 : -EINVAL;
1144                goto unlock;
1145        }
1146
1147        ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
1148        if (!ram_res) {
1149                ret = -ENOMEM;
1150                goto unlock;
1151        }
1152
1153        start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
1154        end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
1155
1156        crash_map_reserved_pages();
1157        crash_free_reserved_phys_range(end, crashk_res.end);
1158
1159        if ((start == end) && (crashk_res.parent != NULL))
1160                release_resource(&crashk_res);
1161
1162        ram_res->start = end;
1163        ram_res->end = crashk_res.end;
1164        ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
1165        ram_res->name = "System RAM";
1166
1167        crashk_res.end = end - 1;
1168
1169        insert_resource(&iomem_resource, ram_res);
1170        crash_unmap_reserved_pages();
1171
1172unlock:
1173        mutex_unlock(&kexec_mutex);
1174        return ret;
1175}
1176
1177static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
1178                            size_t data_len)
1179{
1180        struct elf_note note;
1181
1182        note.n_namesz = strlen(name) + 1;
1183        note.n_descsz = data_len;
1184        note.n_type   = type;
1185        memcpy(buf, &note, sizeof(note));
1186        buf += (sizeof(note) + 3)/4;
1187        memcpy(buf, name, note.n_namesz);
1188        buf += (note.n_namesz + 3)/4;
1189        memcpy(buf, data, note.n_descsz);
1190        buf += (note.n_descsz + 3)/4;
1191
1192        return buf;
1193}
1194
1195static void final_note(u32 *buf)
1196{
1197        struct elf_note note;
1198
1199        note.n_namesz = 0;
1200        note.n_descsz = 0;
1201        note.n_type   = 0;
1202        memcpy(buf, &note, sizeof(note));
1203}
1204
1205void crash_save_cpu(struct pt_regs *regs, int cpu)
1206{
1207        struct elf_prstatus prstatus;
1208        u32 *buf;
1209
1210        if ((cpu < 0) || (cpu >= nr_cpu_ids))
1211                return;
1212
1213        /* Using ELF notes here is opportunistic.
1214         * I need a well defined structure format
1215         * for the data I pass, and I need tags
1216         * on the data to indicate what information I have
1217         * squirrelled away.  ELF notes happen to provide
1218         * all of that, so there is no need to invent something new.
1219         */
1220        buf = (u32*)per_cpu_ptr(crash_notes, cpu);
1221        if (!buf)
1222                return;
1223        memset(&prstatus, 0, sizeof(prstatus));
1224        prstatus.pr_pid = current->pid;
1225        elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
1226        buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
1227                              &prstatus, sizeof(prstatus));
1228        final_note(buf);
1229}
1230
1231static int __init crash_notes_memory_init(void)
1232{
1233        /* Allocate memory for saving cpu registers. */
1234        crash_notes = alloc_percpu(note_buf_t);
1235        if (!crash_notes) {
1236                printk("Kexec: Memory allocation for saving cpu register"
1237                " states failed\n");
1238                return -ENOMEM;
1239        }
1240        return 0;
1241}
1242module_init(crash_notes_memory_init)
1243
1244
1245/*
1246 * parsing the "crashkernel" commandline
1247 *
1248 * this code is intended to be called from architecture specific code
1249 */
1250
1251
1252/*
1253 * This function parses command lines in the format
1254 *
1255 *   crashkernel=ramsize-range:size[,...][@offset]
1256 *
1257 * The function returns 0 on success and -EINVAL on failure.
1258 */
1259static int __init parse_crashkernel_mem(char                    *cmdline,
1260                                        unsigned long long      system_ram,
1261                                        unsigned long long      *crash_size,
1262                                        unsigned long long      *crash_base)
1263{
1264        char *cur = cmdline, *tmp;
1265
1266        /* for each entry of the comma-separated list */
1267        do {
1268                unsigned long long start, end = ULLONG_MAX, size;
1269
1270                /* get the start of the range */
1271                start = memparse(cur, &tmp);
1272                if (cur == tmp) {
1273                        pr_warning("crashkernel: Memory value expected\n");
1274                        return -EINVAL;
1275                }
1276                cur = tmp;
1277                if (*cur != '-') {
1278                        pr_warning("crashkernel: '-' expected\n");
1279                        return -EINVAL;
1280                }
1281                cur++;
1282
1283                /* if no ':' is here, than we read the end */
1284                if (*cur != ':') {
1285                        end = memparse(cur, &tmp);
1286                        if (cur == tmp) {
1287                                pr_warning("crashkernel: Memory "
1288                                                "value expected\n");
1289                                return -EINVAL;
1290                        }
1291                        cur = tmp;
1292                        if (end <= start) {
1293                                pr_warning("crashkernel: end <= start\n");
1294                                return -EINVAL;
1295                        }
1296                }
1297
1298                if (*cur != ':') {
1299                        pr_warning("crashkernel: ':' expected\n");
1300                        return -EINVAL;
1301                }
1302                cur++;
1303
1304                size = memparse(cur, &tmp);
1305                if (cur == tmp) {
1306                        pr_warning("Memory value expected\n");
1307                        return -EINVAL;
1308                }
1309                cur = tmp;
1310                if (size >= system_ram) {
1311                        pr_warning("crashkernel: invalid size\n");
1312                        return -EINVAL;
1313                }
1314
1315                /* match ? */
1316                if (system_ram >= start && system_ram < end) {
1317                        *crash_size = size;
1318                        break;
1319                }
1320        } while (*cur++ == ',');
1321
1322        if (*crash_size > 0) {
1323                while (*cur && *cur != ' ' && *cur != '@')
1324                        cur++;
1325                if (*cur == '@') {
1326                        cur++;
1327                        *crash_base = memparse(cur, &tmp);
1328                        if (cur == tmp) {
1329                                pr_warning("Memory value expected "
1330                                                "after '@'\n");
1331                                return -EINVAL;
1332                        }
1333                }
1334        }
1335
1336        return 0;
1337}
1338
1339/*
1340 * That function parses "simple" (old) crashkernel command lines like
1341 *
1342 *      crashkernel=size[@offset]
1343 *
1344 * It returns 0 on success and -EINVAL on failure.
1345 */
1346static int __init parse_crashkernel_simple(char                 *cmdline,
1347                                           unsigned long long   *crash_size,
1348                                           unsigned long long   *crash_base)
1349{
1350        char *cur = cmdline;
1351
1352        *crash_size = memparse(cmdline, &cur);
1353        if (cmdline == cur) {
1354                pr_warning("crashkernel: memory value expected\n");
1355                return -EINVAL;
1356        }
1357
1358        if (*cur == '@')
1359                *crash_base = memparse(cur+1, &cur);
1360        else if (*cur != ' ' && *cur != '\0') {
1361                pr_warning("crashkernel: unrecognized char\n");
1362                return -EINVAL;
1363        }
1364
1365        return 0;
1366}
1367
1368/*
1369 * That function is the entry point for command line parsing and should be
1370 * called from the arch-specific code.
1371 */
1372int __init parse_crashkernel(char                *cmdline,
1373                             unsigned long long system_ram,
1374                             unsigned long long *crash_size,
1375                             unsigned long long *crash_base)
1376{
1377        char    *p = cmdline, *ck_cmdline = NULL;
1378        char    *first_colon, *first_space;
1379
1380        BUG_ON(!crash_size || !crash_base);
1381        *crash_size = 0;
1382        *crash_base = 0;
1383
1384        /* find crashkernel and use the last one if there are more */
1385        p = strstr(p, "crashkernel=");
1386        while (p) {
1387                ck_cmdline = p;
1388                p = strstr(p+1, "crashkernel=");
1389        }
1390
1391        if (!ck_cmdline)
1392                return -EINVAL;
1393
1394        ck_cmdline += 12; /* strlen("crashkernel=") */
1395
1396        /*
1397         * if the commandline contains a ':', then that's the extended
1398         * syntax -- if not, it must be the classic syntax
1399         */
1400        first_colon = strchr(ck_cmdline, ':');
1401        first_space = strchr(ck_cmdline, ' ');
1402        if (first_colon && (!first_space || first_colon < first_space))
1403                return parse_crashkernel_mem(ck_cmdline, system_ram,
1404                                crash_size, crash_base);
1405        else
1406                return parse_crashkernel_simple(ck_cmdline, crash_size,
1407                                crash_base);
1408
1409        return 0;
1410}
1411
1412
1413static void update_vmcoreinfo_note(void)
1414{
1415        u32 *buf = vmcoreinfo_note;
1416
1417        if (!vmcoreinfo_size)
1418                return;
1419        buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
1420                              vmcoreinfo_size);
1421        final_note(buf);
1422}
1423
1424void crash_save_vmcoreinfo(void)
1425{
1426        vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
1427        update_vmcoreinfo_note();
1428}
1429
1430void vmcoreinfo_append_str(const char *fmt, ...)
1431{
1432        va_list args;
1433        char buf[0x50];
1434        int r;
1435
1436        va_start(args, fmt);
1437        r = vsnprintf(buf, sizeof(buf), fmt, args);
1438        va_end(args);
1439
1440        if (r + vmcoreinfo_size > vmcoreinfo_max_size)
1441                r = vmcoreinfo_max_size - vmcoreinfo_size;
1442
1443        memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
1444
1445        vmcoreinfo_size += r;
1446}
1447
1448/*
1449 * provide an empty default implementation here -- architecture
1450 * code may override this
1451 */
1452void __attribute__ ((weak)) arch_crash_save_vmcoreinfo(void)
1453{}
1454
1455unsigned long __attribute__ ((weak)) paddr_vmcoreinfo_note(void)
1456{
1457        return __pa((unsigned long)(char *)&vmcoreinfo_note);
1458}
1459
1460static int __init crash_save_vmcoreinfo_init(void)
1461{
1462        VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
1463        VMCOREINFO_PAGESIZE(PAGE_SIZE);
1464
1465        VMCOREINFO_SYMBOL(init_uts_ns);
1466        VMCOREINFO_SYMBOL(node_online_map);
1467#ifdef CONFIG_MMU
1468        VMCOREINFO_SYMBOL(swapper_pg_dir);
1469#endif
1470        VMCOREINFO_SYMBOL(_stext);
1471        VMCOREINFO_SYMBOL(vmlist);
1472
1473#ifndef CONFIG_NEED_MULTIPLE_NODES
1474        VMCOREINFO_SYMBOL(mem_map);
1475        VMCOREINFO_SYMBOL(contig_page_data);
1476#endif
1477#ifdef CONFIG_SPARSEMEM
1478        VMCOREINFO_SYMBOL(mem_section);
1479        VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
1480        VMCOREINFO_STRUCT_SIZE(mem_section);
1481        VMCOREINFO_OFFSET(mem_section, section_mem_map);
1482#endif
1483        VMCOREINFO_STRUCT_SIZE(page);
1484        VMCOREINFO_STRUCT_SIZE(pglist_data);
1485        VMCOREINFO_STRUCT_SIZE(zone);
1486        VMCOREINFO_STRUCT_SIZE(free_area);
1487        VMCOREINFO_STRUCT_SIZE(list_head);
1488        VMCOREINFO_SIZE(nodemask_t);
1489        VMCOREINFO_OFFSET(page, flags);
1490        VMCOREINFO_OFFSET(page, _count);
1491        VMCOREINFO_OFFSET(page, mapping);
1492        VMCOREINFO_OFFSET(page, lru);
1493        VMCOREINFO_OFFSET(pglist_data, node_zones);
1494        VMCOREINFO_OFFSET(pglist_data, nr_zones);
1495#ifdef CONFIG_FLAT_NODE_MEM_MAP
1496        VMCOREINFO_OFFSET(pglist_data, node_mem_map);
1497#endif
1498        VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
1499        VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
1500        VMCOREINFO_OFFSET(pglist_data, node_id);
1501        VMCOREINFO_OFFSET(zone, free_area);
1502        VMCOREINFO_OFFSET(zone, vm_stat);
1503        VMCOREINFO_OFFSET(zone, spanned_pages);
1504        VMCOREINFO_OFFSET(free_area, free_list);
1505        VMCOREINFO_OFFSET(list_head, next);
1506        VMCOREINFO_OFFSET(list_head, prev);
1507        VMCOREINFO_OFFSET(vm_struct, addr);
1508        VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
1509        log_buf_kexec_setup();
1510        VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
1511        VMCOREINFO_NUMBER(NR_FREE_PAGES);
1512        VMCOREINFO_NUMBER(PG_lru);
1513        VMCOREINFO_NUMBER(PG_private);
1514        VMCOREINFO_NUMBER(PG_swapcache);
1515
1516        arch_crash_save_vmcoreinfo();
1517        update_vmcoreinfo_note();
1518
1519        return 0;
1520}
1521
1522module_init(crash_save_vmcoreinfo_init)
1523
1524/*
1525 * Move into place and start executing a preloaded standalone
1526 * executable.  If nothing was preloaded return an error.
1527 */
1528int kernel_kexec(void)
1529{
1530        int error = 0;
1531
1532        if (!mutex_trylock(&kexec_mutex))
1533                return -EBUSY;
1534        if (!kexec_image) {
1535                error = -EINVAL;
1536                goto Unlock;
1537        }
1538
1539#ifdef CONFIG_KEXEC_JUMP
1540        if (kexec_image->preserve_context) {
1541                lock_system_sleep();
1542                pm_prepare_console();
1543                error = freeze_processes();
1544                if (error) {
1545                        error = -EBUSY;
1546                        goto Restore_console;
1547                }
1548                suspend_console();
1549                error = dpm_suspend_start(PMSG_FREEZE);
1550                if (error)
1551                        goto Resume_console;
1552                /* At this point, dpm_suspend_start() has been called,
1553                 * but *not* dpm_suspend_end(). We *must* call
1554                 * dpm_suspend_end() now.  Otherwise, drivers for
1555                 * some devices (e.g. interrupt controllers) become
1556                 * desynchronized with the actual state of the
1557                 * hardware at resume time, and evil weirdness ensues.
1558                 */
1559                error = dpm_suspend_end(PMSG_FREEZE);
1560                if (error)
1561                        goto Resume_devices;
1562                error = disable_nonboot_cpus();
1563                if (error)
1564                        goto Enable_cpus;
1565                local_irq_disable();
1566                error = syscore_suspend();
1567                if (error)
1568                        goto Enable_irqs;
1569        } else
1570#endif
1571        {
1572                kernel_restart_prepare(NULL);
1573                printk(KERN_EMERG "Starting new kernel\n");
1574                machine_shutdown();
1575        }
1576
1577        machine_kexec(kexec_image);
1578
1579#ifdef CONFIG_KEXEC_JUMP
1580        if (kexec_image->preserve_context) {
1581                syscore_resume();
1582 Enable_irqs:
1583                local_irq_enable();
1584 Enable_cpus:
1585                enable_nonboot_cpus();
1586                dpm_resume_start(PMSG_RESTORE);
1587 Resume_devices:
1588                dpm_resume_end(PMSG_RESTORE);
1589 Resume_console:
1590                resume_console();
1591                thaw_processes();
1592 Restore_console:
1593                pm_restore_console();
1594                unlock_system_sleep();
1595        }
1596#endif
1597
1598 Unlock:
1599        mutex_unlock(&kexec_mutex);
1600        return error;
1601}
1602
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