kexec: split kexec_load syscall from kexec core code

There are two kexec load syscalls, kexec_load another and kexec_file_load.
 kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
split kexec_load syscall code to kernel/kexec.c.

And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.

The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
kexec_load syscall can bypass the checking.

Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.

Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
kexec_load syscall.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1511 insertions, 0 deletions

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
new file mode 100644
index 000000000000..9aa25c034b2e
--- /dev/null
+++ b/kernel/kexec_core.c
@@ -0,0 +1,1511 @@
+/*
+ * kexec.c - kexec system call core code.
+ * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#define pr_fmt(fmt)     "kexec: " fmt
+
+#include <linux/capability.h>
+#include <linux/mm.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/kexec.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/highmem.h>
+#include <linux/syscalls.h>
+#include <linux/reboot.h>
+#include <linux/ioport.h>
+#include <linux/hardirq.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/utsname.h>
+#include <linux/numa.h>
+#include <linux/suspend.h>
+#include <linux/device.h>
+#include <linux/freezer.h>
+#include <linux/pm.h>
+#include <linux/cpu.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/console.h>
+#include <linux/vmalloc.h>
+#include <linux/swap.h>
+#include <linux/syscore_ops.h>
+#include <linux/compiler.h>
+#include <linux/hugetlb.h>
+
+#include <asm/page.h>
+#include <asm/sections.h>
+
+#include <crypto/hash.h>
+#include <crypto/sha.h>
+#include "kexec_internal.h"
+
+DEFINE_MUTEX(kexec_mutex);
+
+/* Per cpu memory for storing cpu states in case of system crash. */
+note_buf_t __percpu *crash_notes;
+
+/* vmcoreinfo stuff */
+static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
+u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
+size_t vmcoreinfo_size;
+size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
+
+/* Flag to indicate we are going to kexec a new kernel */
+bool kexec_in_progress = false;
+
+
+/* Location of the reserved area for the crash kernel */
+struct resource crashk_res = {
+        .name  = "Crash kernel",
+        .start = 0,
+        .end   = 0,
+        .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+struct resource crashk_low_res = {
+        .name  = "Crash kernel",
+        .start = 0,
+        .end   = 0,
+        .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+
+int kexec_should_crash(struct task_struct *p)
+{
+        /*
+         * If crash_kexec_post_notifiers is enabled, don't run
+         * crash_kexec() here yet, which must be run after panic
+         * notifiers in panic().
+         */
+        if (crash_kexec_post_notifiers)
+                return 0;
+        /*
+         * There are 4 panic() calls in do_exit() path, each of which
+         * corresponds to each of these 4 conditions.
+         */
+        if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)
+                return 1;
+        return 0;
+}
+
+/*
+ * When kexec transitions to the new kernel there is a one-to-one
+ * mapping between physical and virtual addresses.  On processors
+ * where you can disable the MMU this is trivial, and easy.  For
+ * others it is still a simple predictable page table to setup.
+ *
+ * In that environment kexec copies the new kernel to its final
+ * resting place.  This means I can only support memory whose
+ * physical address can fit in an unsigned long.  In particular
+ * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
+ * If the assembly stub has more restrictive requirements
+ * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
+ * defined more restrictively in <asm/kexec.h>.
+ *
+ * The code for the transition from the current kernel to the
+ * the new kernel is placed in the control_code_buffer, whose size
+ * is given by KEXEC_CONTROL_PAGE_SIZE.  In the best case only a single
+ * page of memory is necessary, but some architectures require more.
+ * Because this memory must be identity mapped in the transition from
+ * virtual to physical addresses it must live in the range
+ * 0 - TASK_SIZE, as only the user space mappings are arbitrarily
+ * modifiable.
+ *
+ * The assembly stub in the control code buffer is passed a linked list
+ * of descriptor pages detailing the source pages of the new kernel,
+ * and the destination addresses of those source pages.  As this data
+ * structure is not used in the context of the current OS, it must
+ * be self-contained.
+ *
+ * The code has been made to work with highmem pages and will use a
+ * destination page in its final resting place (if it happens
+ * to allocate it).  The end product of this is that most of the
+ * physical address space, and most of RAM can be used.
+ *
+ * Future directions include:
+ *  - allocating a page table with the control code buffer identity
+ *    mapped, to simplify machine_kexec and make kexec_on_panic more
+ *    reliable.
+ */
+
+/*
+ * KIMAGE_NO_DEST is an impossible destination address..., for
+ * allocating pages whose destination address we do not care about.
+ */
+#define KIMAGE_NO_DEST (-1UL)
+
+static struct page *kimage_alloc_page(struct kimage *image,
+                                       gfp_t gfp_mask,
+                                       unsigned long dest);
+
+int sanity_check_segment_list(struct kimage *image)
+{
+        int result, i;
+        unsigned long nr_segments = image->nr_segments;
+
+        /*
+         * Verify we have good destination addresses.  The caller is
+         * responsible for making certain we don't attempt to load
+         * the new image into invalid or reserved areas of RAM.  This
+         * just verifies it is an address we can use.
+         *
+         * Since the kernel does everything in page size chunks ensure
+         * the destination addresses are page aligned.  Too many
+         * special cases crop of when we don't do this.  The most
+         * insidious is getting overlapping destination addresses
+         * simply because addresses are changed to page size
+         * granularity.
+         */
+        result = -EADDRNOTAVAIL;
+        for (i = 0; i < nr_segments; i++) {
+                unsigned long mstart, mend;
+
+                mstart = image->segment[i].mem;
+                mend   = mstart + image->segment[i].memsz;
+                if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
+                        return result;
+                if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
+                        return result;
+        }
+
+        /* Verify our destination addresses do not overlap.
+         * If we alloed overlapping destination addresses
+         * through very weird things can happen with no
+         * easy explanation as one segment stops on another.
+         */
+        result = -EINVAL;
+        for (i = 0; i < nr_segments; i++) {
+                unsigned long mstart, mend;
+                unsigned long j;
+
+                mstart = image->segment[i].mem;
+                mend   = mstart + image->segment[i].memsz;
+                for (j = 0; j < i; j++) {
+                        unsigned long pstart, pend;
+
+                        pstart = image->segment[j].mem;
+                        pend   = pstart + image->segment[j].memsz;
+                        /* Do the segments overlap ? */
+                        if ((mend > pstart) && (mstart < pend))
+                                return result;
+                }
+        }
+
+        /* Ensure our buffer sizes are strictly less than
+         * our memory sizes.  This should always be the case,
+         * and it is easier to check up front than to be surprised
+         * later on.
+         */
+        result = -EINVAL;
+        for (i = 0; i < nr_segments; i++) {
+                if (image->segment[i].bufsz > image->segment[i].memsz)
+                        return result;
+        }
+
+        /*
+         * Verify we have good destination addresses.  Normally
+         * the caller is responsible for making certain we don't
+         * attempt to load the new image into invalid or reserved
+         * areas of RAM.  But crash kernels are preloaded into a
+         * reserved area of ram.  We must ensure the addresses
+         * are in the reserved area otherwise preloading the
+         * kernel could corrupt things.
+         */
+
+        if (image->type == KEXEC_TYPE_CRASH) {
+                result = -EADDRNOTAVAIL;
+                for (i = 0; i < nr_segments; i++) {
+                        unsigned long mstart, mend;
+
+                        mstart = image->segment[i].mem;
+                        mend = mstart + image->segment[i].memsz - 1;
+                        /* Ensure we are within the crash kernel limits */
+                        if ((mstart < crashk_res.start) ||
+                            (mend > crashk_res.end))
+                                return result;
+                }
+        }
+
+        return 0;
+}
+
+struct kimage *do_kimage_alloc_init(void)
+{
+        struct kimage *image;
+
+        /* Allocate a controlling structure */
+        image = kzalloc(sizeof(*image), GFP_KERNEL);
+        if (!image)
+                return NULL;
+
+        image->head = 0;
+        image->entry = &image->head;
+        image->last_entry = &image->head;
+        image->control_page = ~0; /* By default this does not apply */
+        image->type = KEXEC_TYPE_DEFAULT;
+
+        /* Initialize the list of control pages */
+        INIT_LIST_HEAD(&image->control_pages);
+
+        /* Initialize the list of destination pages */
+        INIT_LIST_HEAD(&image->dest_pages);
+
+        /* Initialize the list of unusable pages */
+        INIT_LIST_HEAD(&image->unusable_pages);
+
+        return image;
+}
+
+int kimage_is_destination_range(struct kimage *image,
+                                        unsigned long start,
+                                        unsigned long end)
+{
+        unsigned long i;
+
+        for (i = 0; i < image->nr_segments; i++) {
+                unsigned long mstart, mend;
+
+                mstart = image->segment[i].mem;
+                mend = mstart + image->segment[i].memsz;
+                if ((end > mstart) && (start < mend))
+                        return 1;
+        }
+
+        return 0;
+}
+
+static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
+{
+        struct page *pages;
+
+        pages = alloc_pages(gfp_mask, order);
+        if (pages) {
+                unsigned int count, i;
+
+                pages->mapping = NULL;
+                set_page_private(pages, order);
+                count = 1 << order;
+                for (i = 0; i < count; i++)
+                        SetPageReserved(pages + i);
+        }
+
+        return pages;
+}
+
+static void kimage_free_pages(struct page *page)
+{
+        unsigned int order, count, i;
+
+        order = page_private(page);
+        count = 1 << order;
+        for (i = 0; i < count; i++)
+                ClearPageReserved(page + i);
+        __free_pages(page, order);
+}
+
+void kimage_free_page_list(struct list_head *list)
+{
+        struct list_head *pos, *next;
+
+        list_for_each_safe(pos, next, list) {
+                struct page *page;
+
+                page = list_entry(pos, struct page, lru);
+                list_del(&page->lru);
+                kimage_free_pages(page);
+        }
+}
+
+static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
+                                                        unsigned int order)
+{
+        /* Control pages are special, they are the intermediaries
+         * that are needed while we copy the rest of the pages
+         * to their final resting place.  As such they must
+         * not conflict with either the destination addresses
+         * or memory the kernel is already using.
+         *
+         * The only case where we really need more than one of
+         * these are for architectures where we cannot disable
+         * the MMU and must instead generate an identity mapped
+         * page table for all of the memory.
+         *
+         * At worst this runs in O(N) of the image size.
+         */
+        struct list_head extra_pages;
+        struct page *pages;
+        unsigned int count;
+
+        count = 1 << order;
+        INIT_LIST_HEAD(&extra_pages);
+
+        /* Loop while I can allocate a page and the page allocated
+         * is a destination page.
+         */
+        do {
+                unsigned long pfn, epfn, addr, eaddr;
+
+                pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order);
+                if (!pages)
+                        break;
+                pfn   = page_to_pfn(pages);
+                epfn  = pfn + count;
+                addr  = pfn << PAGE_SHIFT;
+                eaddr = epfn << PAGE_SHIFT;
+                if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
+                              kimage_is_destination_range(image, addr, eaddr)) {
+                        list_add(&pages->lru, &extra_pages);
+                        pages = NULL;
+                }
+        } while (!pages);
+
+        if (pages) {
+                /* Remember the allocated page... */
+                list_add(&pages->lru, &image->control_pages);
+
+                /* Because the page is already in it's destination
+                 * location we will never allocate another page at
+                 * that address.  Therefore kimage_alloc_pages
+                 * will not return it (again) and we don't need
+                 * to give it an entry in image->segment[].
+                 */
+        }
+        /* Deal with the destination pages I have inadvertently allocated.
+         *
+         * Ideally I would convert multi-page allocations into single
+         * page allocations, and add everything to image->dest_pages.
+         *
+         * For now it is simpler to just free the pages.
+         */
+        kimage_free_page_list(&extra_pages);
+
+        return pages;
+}
+
+static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
+                                                      unsigned int order)
+{
+        /* Control pages are special, they are the intermediaries
+         * that are needed while we copy the rest of the pages
+         * to their final resting place.  As such they must
+         * not conflict with either the destination addresses
+         * or memory the kernel is already using.
+         *
+         * Control pages are also the only pags we must allocate
+         * when loading a crash kernel.  All of the other pages
+         * are specified by the segments and we just memcpy
+         * into them directly.
+         *
+         * The only case where we really need more than one of
+         * these are for architectures where we cannot disable
+         * the MMU and must instead generate an identity mapped
+         * page table for all of the memory.
+         *
+         * Given the low demand this implements a very simple
+         * allocator that finds the first hole of the appropriate
+         * size in the reserved memory region, and allocates all
+         * of the memory up to and including the hole.
+         */
+        unsigned long hole_start, hole_end, size;
+        struct page *pages;
+
+        pages = NULL;
+        size = (1 << order) << PAGE_SHIFT;
+        hole_start = (image->control_page + (size - 1)) & ~(size - 1);
+        hole_end   = hole_start + size - 1;
+        while (hole_end <= crashk_res.end) {
+                unsigned long i;
+
+                if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
+                        break;
+                /* See if I overlap any of the segments */
+                for (i = 0; i < image->nr_segments; i++) {
+                        unsigned long mstart, mend;
+
+                        mstart = image->segment[i].mem;
+                        mend   = mstart + image->segment[i].memsz - 1;
+                        if ((hole_end >= mstart) && (hole_start <= mend)) {
+                                /* Advance the hole to the end of the segment */
+                                hole_start = (mend + (size - 1)) & ~(size - 1);
+                                hole_end   = hole_start + size - 1;
+                                break;
+                        }
+                }
+                /* If I don't overlap any segments I have found my hole! */
+                if (i == image->nr_segments) {
+                        pages = pfn_to_page(hole_start >> PAGE_SHIFT);
+                        break;
+                }
+        }
+        if (pages)
+                image->control_page = hole_end;
+
+        return pages;
+}
+
+
+struct page *kimage_alloc_control_pages(struct kimage *image,
+                                         unsigned int order)
+{
+        struct page *pages = NULL;
+
+        switch (image->type) {
+        case KEXEC_TYPE_DEFAULT:
+                pages = kimage_alloc_normal_control_pages(image, order);
+                break;
+        case KEXEC_TYPE_CRASH:
+                pages = kimage_alloc_crash_control_pages(image, order);
+                break;
+        }
+
+        return pages;
+}
+
+static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
+{
+        if (*image->entry != 0)
+                image->entry++;
+
+        if (image->entry == image->last_entry) {
+                kimage_entry_t *ind_page;
+                struct page *page;
+
+                page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
+                if (!page)
+                        return -ENOMEM;
+
+                ind_page = page_address(page);
+                *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
+                image->entry = ind_page;
+                image->last_entry = ind_page +
+                                      ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
+        }
+        *image->entry = entry;
+        image->entry++;
+        *image->entry = 0;
+
+        return 0;
+}
+
+static int kimage_set_destination(struct kimage *image,
+                                   unsigned long destination)
+{
+        int result;
+
+        destination &= PAGE_MASK;
+        result = kimage_add_entry(image, destination | IND_DESTINATION);
+
+        return result;
+}
+
+
+static int kimage_add_page(struct kimage *image, unsigned long page)
+{
+        int result;
+
+        page &= PAGE_MASK;
+        result = kimage_add_entry(image, page | IND_SOURCE);
+
+        return result;
+}
+
+
+static void kimage_free_extra_pages(struct kimage *image)
+{
+        /* Walk through and free any extra destination pages I may have */
+        kimage_free_page_list(&image->dest_pages);
+
+        /* Walk through and free any unusable pages I have cached */
+        kimage_free_page_list(&image->unusable_pages);
+
+}
+void kimage_terminate(struct kimage *image)
+{
+        if (*image->entry != 0)
+                image->entry++;
+
+        *image->entry = IND_DONE;
+}
+
+#define for_each_kimage_entry(image, ptr, entry) \
+        for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
+                ptr = (entry & IND_INDIRECTION) ? \
+                        phys_to_virt((entry & PAGE_MASK)) : ptr + 1)
+
+static void kimage_free_entry(kimage_entry_t entry)
+{
+        struct page *page;
+
+        page = pfn_to_page(entry >> PAGE_SHIFT);
+        kimage_free_pages(page);
+}
+
+void kimage_free(struct kimage *image)
+{
+        kimage_entry_t *ptr, entry;
+        kimage_entry_t ind = 0;
+
+        if (!image)
+                return;
+
+        kimage_free_extra_pages(image);
+        for_each_kimage_entry(image, ptr, entry) {
+                if (entry & IND_INDIRECTION) {
+                        /* Free the previous indirection page */
+                        if (ind & IND_INDIRECTION)
+                                kimage_free_entry(ind);
+                        /* Save this indirection page until we are
+                         * done with it.
+                         */
+                        ind = entry;
+                } else if (entry & IND_SOURCE)
+                        kimage_free_entry(entry);
+        }
+        /* Free the final indirection page */
+        if (ind & IND_INDIRECTION)
+                kimage_free_entry(ind);
+
+        /* Handle any machine specific cleanup */
+        machine_kexec_cleanup(image);
+
+        /* Free the kexec control pages... */
+        kimage_free_page_list(&image->control_pages);
+
+        /*
+         * Free up any temporary buffers allocated. This might hit if
+         * error occurred much later after buffer allocation.
+         */
+        if (image->file_mode)
+                kimage_file_post_load_cleanup(image);
+
+        kfree(image);
+}
+
+static kimage_entry_t *kimage_dst_used(struct kimage *image,
+                                        unsigned long page)
+{
+        kimage_entry_t *ptr, entry;
+        unsigned long destination = 0;
+
+        for_each_kimage_entry(image, ptr, entry) {
+                if (entry & IND_DESTINATION)
+                        destination = entry & PAGE_MASK;
+                else if (entry & IND_SOURCE) {
+                        if (page == destination)
+                                return ptr;
+                        destination += PAGE_SIZE;
+                }
+        }
+
+        return NULL;
+}
+
+static struct page *kimage_alloc_page(struct kimage *image,
+                                        gfp_t gfp_mask,
+                                        unsigned long destination)
+{
+        /*
+         * Here we implement safeguards to ensure that a source page
+         * is not copied to its destination page before the data on
+         * the destination page is no longer useful.
+         *
+         * To do this we maintain the invariant that a source page is
+         * either its own destination page, or it is not a
+         * destination page at all.
+         *
+         * That is slightly stronger than required, but the proof
+         * that no problems will not occur is trivial, and the
+         * implementation is simply to verify.
+         *
+         * When allocating all pages normally this algorithm will run
+         * in O(N) time, but in the worst case it will run in O(N^2)
+         * time.   If the runtime is a problem the data structures can
+         * be fixed.
+         */
+        struct page *page;
+        unsigned long addr;
+
+        /*
+         * Walk through the list of destination pages, and see if I
+         * have a match.
+         */
+        list_for_each_entry(page, &image->dest_pages, lru) {
+                addr = page_to_pfn(page) << PAGE_SHIFT;
+                if (addr == destination) {
+                        list_del(&page->lru);
+                        return page;
+                }
+        }
+        page = NULL;
+        while (1) {
+                kimage_entry_t *old;
+
+                /* Allocate a page, if we run out of memory give up */
+                page = kimage_alloc_pages(gfp_mask, 0);
+                if (!page)
+                        return NULL;
+                /* If the page cannot be used file it away */
+                if (page_to_pfn(page) >
+                                (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
+                        list_add(&page->lru, &image->unusable_pages);
+                        continue;
+                }
+                addr = page_to_pfn(page) << PAGE_SHIFT;
+
+                /* If it is the destination page we want use it */
+                if (addr == destination)
+                        break;
+
+                /* If the page is not a destination page use it */
+                if (!kimage_is_destination_range(image, addr,
+                                                  addr + PAGE_SIZE))
+                        break;
+
+                /*
+                 * I know that the page is someones destination page.
+                 * See if there is already a source page for this
+                 * destination page.  And if so swap the source pages.
+                 */
+                old = kimage_dst_used(image, addr);
+                if (old) {
+                        /* If so move it */
+                        unsigned long old_addr;
+                        struct page *old_page;
+
+                        old_addr = *old & PAGE_MASK;
+                        old_page = pfn_to_page(old_addr >> PAGE_SHIFT);
+                        copy_highpage(page, old_page);
+                        *old = addr | (*old & ~PAGE_MASK);
+
+                        /* The old page I have found cannot be a
+                         * destination page, so return it if it's
+                         * gfp_flags honor the ones passed in.
+                         */
+                        if (!(gfp_mask & __GFP_HIGHMEM) &&
+                            PageHighMem(old_page)) {
+                                kimage_free_pages(old_page);
+                                continue;
+                        }
+                        addr = old_addr;
+                        page = old_page;
+                        break;
+                }
+                /* Place the page on the destination list, to be used later */
+                list_add(&page->lru, &image->dest_pages);
+        }
+
+        return page;
+}
+
+static int kimage_load_normal_segment(struct kimage *image,
+                                         struct kexec_segment *segment)
+{
+        unsigned long maddr;
+        size_t ubytes, mbytes;
+        int result;
+        unsigned char __user *buf = NULL;
+        unsigned char *kbuf = NULL;
+
+        result = 0;
+        if (image->file_mode)
+                kbuf = segment->kbuf;
+        else
+                buf = segment->buf;
+        ubytes = segment->bufsz;
+        mbytes = segment->memsz;
+        maddr = segment->mem;
+
+        result = kimage_set_destination(image, maddr);
+        if (result < 0)
+                goto out;
+
+        while (mbytes) {
+                struct page *page;
+                char *ptr;
+                size_t uchunk, mchunk;
+
+                page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
+                if (!page) {
+                        result  = -ENOMEM;
+                        goto out;
+                }
+                result = kimage_add_page(image, page_to_pfn(page)
+                                                                << PAGE_SHIFT);
+                if (result < 0)
+                        goto out;
+
+                ptr = kmap(page);
+                /* Start with a clear page */
+                clear_page(ptr);
+                ptr += maddr & ~PAGE_MASK;
+                mchunk = min_t(size_t, mbytes,
+                                PAGE_SIZE - (maddr & ~PAGE_MASK));
+                uchunk = min(ubytes, mchunk);
+
+                /* For file based kexec, source pages are in kernel memory */
+                if (image->file_mode)
+                        memcpy(ptr, kbuf, uchunk);
+                else
+                        result = copy_from_user(ptr, buf, uchunk);
+                kunmap(page);
+                if (result) {
+                        result = -EFAULT;
+                        goto out;
+                }
+                ubytes -= uchunk;
+                maddr  += mchunk;
+                if (image->file_mode)
+                        kbuf += mchunk;
+                else
+                        buf += mchunk;
+                mbytes -= mchunk;
+        }
+out:
+        return result;
+}
+
+static int kimage_load_crash_segment(struct kimage *image,
+                                        struct kexec_segment *segment)
+{
+        /* For crash dumps kernels we simply copy the data from
+         * user space to it's destination.
+         * We do things a page at a time for the sake of kmap.
+         */
+        unsigned long maddr;
+        size_t ubytes, mbytes;
+        int result;
+        unsigned char __user *buf = NULL;
+        unsigned char *kbuf = NULL;
+
+        result = 0;
+        if (image->file_mode)
+                kbuf = segment->kbuf;
+        else
+                buf = segment->buf;
+        ubytes = segment->bufsz;
+        mbytes = segment->memsz;
+        maddr = segment->mem;
+        while (mbytes) {
+                struct page *page;
+                char *ptr;
+                size_t uchunk, mchunk;
+
+                page = pfn_to_page(maddr >> PAGE_SHIFT);
+                if (!page) {
+                        result  = -ENOMEM;
+                        goto out;
+                }
+                ptr = kmap(page);
+                ptr += maddr & ~PAGE_MASK;
+                mchunk = min_t(size_t, mbytes,
+                                PAGE_SIZE - (maddr & ~PAGE_MASK));
+                uchunk = min(ubytes, mchunk);
+                if (mchunk > uchunk) {
+                        /* Zero the trailing part of the page */
+                        memset(ptr + uchunk, 0, mchunk - uchunk);
+                }
+
+                /* For file based kexec, source pages are in kernel memory */
+                if (image->file_mode)
+                        memcpy(ptr, kbuf, uchunk);
+                else
+                        result = copy_from_user(ptr, buf, uchunk);
+                kexec_flush_icache_page(page);
+                kunmap(page);
+                if (result) {
+                        result = -EFAULT;
+                        goto out;
+                }
+                ubytes -= uchunk;
+                maddr  += mchunk;
+                if (image->file_mode)
+                        kbuf += mchunk;
+                else
+                        buf += mchunk;
+                mbytes -= mchunk;
+        }
+out:
+        return result;
+}
+
+int kimage_load_segment(struct kimage *image,
+                                struct kexec_segment *segment)
+{
+        int result = -ENOMEM;
+
+        switch (image->type) {
+        case KEXEC_TYPE_DEFAULT:
+                result = kimage_load_normal_segment(image, segment);
+                break;
+        case KEXEC_TYPE_CRASH:
+                result = kimage_load_crash_segment(image, segment);
+                break;
+        }
+
+        return result;
+}
+
+struct kimage *kexec_image;
+struct kimage *kexec_crash_image;
+int kexec_load_disabled;
+
+void crash_kexec(struct pt_regs *regs)
+{
+        /* Take the kexec_mutex here to prevent sys_kexec_load
+         * running on one cpu from replacing the crash kernel
+         * we are using after a panic on a different cpu.
+         *
+         * If the crash kernel was not located in a fixed area
+         * of memory the xchg(&kexec_crash_image) would be
+         * sufficient.  But since I reuse the memory...
+         */
+        if (mutex_trylock(&kexec_mutex)) {
+                if (kexec_crash_image) {
+                        struct pt_regs fixed_regs;
+
+                        crash_setup_regs(&fixed_regs, regs);
+                        crash_save_vmcoreinfo();
+                        machine_crash_shutdown(&fixed_regs);
+                        machine_kexec(kexec_crash_image);
+                }
+                mutex_unlock(&kexec_mutex);
+        }
+}
+
+size_t crash_get_memory_size(void)
+{
+        size_t size = 0;
+
+        mutex_lock(&kexec_mutex);
+        if (crashk_res.end != crashk_res.start)
+                size = resource_size(&crashk_res);
+        mutex_unlock(&kexec_mutex);
+        return size;
+}
+
+void __weak crash_free_reserved_phys_range(unsigned long begin,
+                                           unsigned long end)
+{
+        unsigned long addr;
+
+        for (addr = begin; addr < end; addr += PAGE_SIZE)
+                free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
+}
+
+int crash_shrink_memory(unsigned long new_size)
+{
+        int ret = 0;
+        unsigned long start, end;
+        unsigned long old_size;
+        struct resource *ram_res;
+
+        mutex_lock(&kexec_mutex);
+
+        if (kexec_crash_image) {
+                ret = -ENOENT;
+                goto unlock;
+        }
+        start = crashk_res.start;
+        end = crashk_res.end;
+        old_size = (end == 0) ? 0 : end - start + 1;
+        if (new_size >= old_size) {
+                ret = (new_size == old_size) ? 0 : -EINVAL;
+                goto unlock;
+        }
+
+        ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
+        if (!ram_res) {
+                ret = -ENOMEM;
+                goto unlock;
+        }
+
+        start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
+        end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
+
+        crash_map_reserved_pages();
+        crash_free_reserved_phys_range(end, crashk_res.end);
+
+        if ((start == end) && (crashk_res.parent != NULL))
+                release_resource(&crashk_res);
+
+        ram_res->start = end;
+        ram_res->end = crashk_res.end;
+        ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
+        ram_res->name = "System RAM";
+
+        crashk_res.end = end - 1;
+
+        insert_resource(&iomem_resource, ram_res);
+        crash_unmap_reserved_pages();
+
+unlock:
+        mutex_unlock(&kexec_mutex);
+        return ret;
+}
+
+static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
+                            size_t data_len)
+{
+        struct elf_note note;
+
+        note.n_namesz = strlen(name) + 1;
+        note.n_descsz = data_len;
+        note.n_type   = type;
+        memcpy(buf, &note, sizeof(note));
+        buf += (sizeof(note) + 3)/4;
+        memcpy(buf, name, note.n_namesz);
+        buf += (note.n_namesz + 3)/4;
+        memcpy(buf, data, note.n_descsz);
+        buf += (note.n_descsz + 3)/4;
+
+        return buf;
+}
+
+static void final_note(u32 *buf)
+{
+        struct elf_note note;
+
+        note.n_namesz = 0;
+        note.n_descsz = 0;
+        note.n_type   = 0;
+        memcpy(buf, &note, sizeof(note));
+}
+
+void crash_save_cpu(struct pt_regs *regs, int cpu)
+{
+        struct elf_prstatus prstatus;
+        u32 *buf;
+
+        if ((cpu < 0) || (cpu >= nr_cpu_ids))
+                return;
+
+        /* Using ELF notes here is opportunistic.
+         * I need a well defined structure format
+         * for the data I pass, and I need tags
+         * on the data to indicate what information I have
+         * squirrelled away.  ELF notes happen to provide
+         * all of that, so there is no need to invent something new.
+         */
+        buf = (u32 *)per_cpu_ptr(crash_notes, cpu);
+        if (!buf)
+                return;
+        memset(&prstatus, 0, sizeof(prstatus));
+        prstatus.pr_pid = current->pid;
+        elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
+        buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
+                              &prstatus, sizeof(prstatus));
+        final_note(buf);
+}
+
+static int __init crash_notes_memory_init(void)
+{
+        /* Allocate memory for saving cpu registers. */
+        crash_notes = alloc_percpu(note_buf_t);
+        if (!crash_notes) {
+                pr_warn("Kexec: Memory allocation for saving cpu register states failed\n");
+                return -ENOMEM;
+        }
+        return 0;
+}
+subsys_initcall(crash_notes_memory_init);
+
+
+/*
+ * parsing the "crashkernel" commandline
+ *
+ * this code is intended to be called from architecture specific code
+ */
+
+
+/*
+ * This function parses command lines in the format
+ *
+ *   crashkernel=ramsize-range:size[,...][@offset]
+ *
+ * The function returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_mem(char *cmdline,
+                                        unsigned long long system_ram,
+                                        unsigned long long *crash_size,
+                                        unsigned long long *crash_base)
+{
+        char *cur = cmdline, *tmp;
+
+        /* for each entry of the comma-separated list */
+        do {
+                unsigned long long start, end = ULLONG_MAX, size;
+
+                /* get the start of the range */
+                start = memparse(cur, &tmp);
+                if (cur == tmp) {
+                        pr_warn("crashkernel: Memory value expected\n");
+                        return -EINVAL;
+                }
+                cur = tmp;
+                if (*cur != '-') {
+                        pr_warn("crashkernel: '-' expected\n");
+                        return -EINVAL;
+                }
+                cur++;
+
+                /* if no ':' is here, than we read the end */
+                if (*cur != ':') {
+                        end = memparse(cur, &tmp);
+                        if (cur == tmp) {
+                                pr_warn("crashkernel: Memory value expected\n");
+                                return -EINVAL;
+                        }
+                        cur = tmp;
+                        if (end <= start) {
+                                pr_warn("crashkernel: end <= start\n");
+                                return -EINVAL;
+                        }
+                }
+
+                if (*cur != ':') {
+                        pr_warn("crashkernel: ':' expected\n");
+                        return -EINVAL;
+                }
+                cur++;
+
+                size = memparse(cur, &tmp);
+                if (cur == tmp) {
+                        pr_warn("Memory value expected\n");
+                        return -EINVAL;
+                }
+                cur = tmp;
+                if (size >= system_ram) {
+                        pr_warn("crashkernel: invalid size\n");
+                        return -EINVAL;
+                }
+
+                /* match ? */
+                if (system_ram >= start && system_ram < end) {
+                        *crash_size = size;
+                        break;
+                }
+        } while (*cur++ == ',');
+
+        if (*crash_size > 0) {
+                while (*cur && *cur != ' ' && *cur != '@')
+                        cur++;
+                if (*cur == '@') {
+                        cur++;
+                        *crash_base = memparse(cur, &tmp);
+                        if (cur == tmp) {
+                                pr_warn("Memory value expected after '@'\n");
+                                return -EINVAL;
+                        }
+                }
+        }
+
+        return 0;
+}
+
+/*
+ * That function parses "simple" (old) crashkernel command lines like
+ *
+ *      crashkernel=size[@offset]
+ *
+ * It returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_simple(char *cmdline,
+                                           unsigned long long *crash_size,
+                                           unsigned long long *crash_base)
+{
+        char *cur = cmdline;
+
+        *crash_size = memparse(cmdline, &cur);
+        if (cmdline == cur) {
+                pr_warn("crashkernel: memory value expected\n");
+                return -EINVAL;
+        }
+
+        if (*cur == '@')
+                *crash_base = memparse(cur+1, &cur);
+        else if (*cur != ' ' && *cur != '\0') {
+                pr_warn("crashkernel: unrecognized char\n");
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+#define SUFFIX_HIGH 0
+#define SUFFIX_LOW  1
+#define SUFFIX_NULL 2
+static __initdata char *suffix_tbl[] = {
+        [SUFFIX_HIGH] = ",high",
+        [SUFFIX_LOW]  = ",low",
+        [SUFFIX_NULL] = NULL,
+};
+
+/*
+ * That function parses "suffix"  crashkernel command lines like
+ *
+ *      crashkernel=size,[high|low]
+ *
+ * It returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_suffix(char *cmdline,
+                                           unsigned long long   *crash_size,
+                                           const char *suffix)
+{
+        char *cur = cmdline;
+
+        *crash_size = memparse(cmdline, &cur);
+        if (cmdline == cur) {
+                pr_warn("crashkernel: memory value expected\n");
+                return -EINVAL;
+        }
+
+        /* check with suffix */
+        if (strncmp(cur, suffix, strlen(suffix))) {
+                pr_warn("crashkernel: unrecognized char\n");
+                return -EINVAL;
+        }
+        cur += strlen(suffix);
+        if (*cur != ' ' && *cur != '\0') {
+                pr_warn("crashkernel: unrecognized char\n");
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static __init char *get_last_crashkernel(char *cmdline,
+                             const char *name,
+                             const char *suffix)
+{
+        char *p = cmdline, *ck_cmdline = NULL;
+
+        /* find crashkernel and use the last one if there are more */
+        p = strstr(p, name);
+        while (p) {
+                char *end_p = strchr(p, ' ');
+                char *q;
+
+                if (!end_p)
+                        end_p = p + strlen(p);
+
+                if (!suffix) {
+                        int i;
+
+                        /* skip the one with any known suffix */
+                        for (i = 0; suffix_tbl[i]; i++) {
+                                q = end_p - strlen(suffix_tbl[i]);
+                                if (!strncmp(q, suffix_tbl[i],
+                                             strlen(suffix_tbl[i])))
+                                        goto next;
+                        }
+                        ck_cmdline = p;
+                } else {
+                        q = end_p - strlen(suffix);
+                        if (!strncmp(q, suffix, strlen(suffix)))
+                                ck_cmdline = p;
+                }
+next:
+                p = strstr(p+1, name);
+        }
+
+        if (!ck_cmdline)
+                return NULL;
+
+        return ck_cmdline;
+}
+
+static int __init __parse_crashkernel(char *cmdline,
+                             unsigned long long system_ram,
+                             unsigned long long *crash_size,
+                             unsigned long long *crash_base,
+                             const char *name,
+                             const char *suffix)
+{
+        char    *first_colon, *first_space;
+        char    *ck_cmdline;
+
+        BUG_ON(!crash_size || !crash_base);
+        *crash_size = 0;
+        *crash_base = 0;
+
+        ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
+
+        if (!ck_cmdline)
+                return -EINVAL;
+
+        ck_cmdline += strlen(name);
+
+        if (suffix)
+                return parse_crashkernel_suffix(ck_cmdline, crash_size,
+                                suffix);
+        /*
+         * if the commandline contains a ':', then that's the extended
+         * syntax -- if not, it must be the classic syntax
+         */
+        first_colon = strchr(ck_cmdline, ':');
+        first_space = strchr(ck_cmdline, ' ');
+        if (first_colon && (!first_space || first_colon < first_space))
+                return parse_crashkernel_mem(ck_cmdline, system_ram,
+                                crash_size, crash_base);
+
+        return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
+}
+
+/*
+ * That function is the entry point for command line parsing and should be
+ * called from the arch-specific code.
+ */
+int __init parse_crashkernel(char *cmdline,
+                             unsigned long long system_ram,
+                             unsigned long long *crash_size,
+                             unsigned long long *crash_base)
+{
+        return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+                                        "crashkernel=", NULL);
+}
+
+int __init parse_crashkernel_high(char *cmdline,
+                             unsigned long long system_ram,
+                             unsigned long long *crash_size,
+                             unsigned long long *crash_base)
+{
+        return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+                                "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
+}
+
+int __init parse_crashkernel_low(char *cmdline,
+                             unsigned long long system_ram,
+                             unsigned long long *crash_size,
+                             unsigned long long *crash_base)
+{
+        return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+                                "crashkernel=", suffix_tbl[SUFFIX_LOW]);
+}
+
+static void update_vmcoreinfo_note(void)
+{
+        u32 *buf = vmcoreinfo_note;
+
+        if (!vmcoreinfo_size)
+                return;
+        buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
+                              vmcoreinfo_size);
+        final_note(buf);
+}
+
+void crash_save_vmcoreinfo(void)
+{
+        vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
+        update_vmcoreinfo_note();
+}
+
+void vmcoreinfo_append_str(const char *fmt, ...)
+{
+        va_list args;
+        char buf[0x50];
+        size_t r;
+
+        va_start(args, fmt);
+        r = vscnprintf(buf, sizeof(buf), fmt, args);
+        va_end(args);
+
+        r = min(r, vmcoreinfo_max_size - vmcoreinfo_size);
+
+        memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
+
+        vmcoreinfo_size += r;
+}
+
+/*
+ * provide an empty default implementation here -- architecture
+ * code may override this
+ */
+void __weak arch_crash_save_vmcoreinfo(void)
+{}
+
+unsigned long __weak paddr_vmcoreinfo_note(void)
+{
+        return __pa((unsigned long)(char *)&vmcoreinfo_note);
+}
+
+static int __init crash_save_vmcoreinfo_init(void)
+{
+        VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
+        VMCOREINFO_PAGESIZE(PAGE_SIZE);
+
+        VMCOREINFO_SYMBOL(init_uts_ns);
+        VMCOREINFO_SYMBOL(node_online_map);
+#ifdef CONFIG_MMU
+        VMCOREINFO_SYMBOL(swapper_pg_dir);
+#endif
+        VMCOREINFO_SYMBOL(_stext);
+        VMCOREINFO_SYMBOL(vmap_area_list);
+
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+        VMCOREINFO_SYMBOL(mem_map);
+        VMCOREINFO_SYMBOL(contig_page_data);
+#endif
+#ifdef CONFIG_SPARSEMEM
+        VMCOREINFO_SYMBOL(mem_section);
+        VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
+        VMCOREINFO_STRUCT_SIZE(mem_section);
+        VMCOREINFO_OFFSET(mem_section, section_mem_map);
+#endif
+        VMCOREINFO_STRUCT_SIZE(page);
+        VMCOREINFO_STRUCT_SIZE(pglist_data);
+        VMCOREINFO_STRUCT_SIZE(zone);
+        VMCOREINFO_STRUCT_SIZE(free_area);
+        VMCOREINFO_STRUCT_SIZE(list_head);
+        VMCOREINFO_SIZE(nodemask_t);
+        VMCOREINFO_OFFSET(page, flags);
+        VMCOREINFO_OFFSET(page, _count);
+        VMCOREINFO_OFFSET(page, mapping);
+        VMCOREINFO_OFFSET(page, lru);
+        VMCOREINFO_OFFSET(page, _mapcount);
+        VMCOREINFO_OFFSET(page, private);
+        VMCOREINFO_OFFSET(pglist_data, node_zones);
+        VMCOREINFO_OFFSET(pglist_data, nr_zones);
+#ifdef CONFIG_FLAT_NODE_MEM_MAP
+        VMCOREINFO_OFFSET(pglist_data, node_mem_map);
+#endif
+        VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
+        VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
+        VMCOREINFO_OFFSET(pglist_data, node_id);
+        VMCOREINFO_OFFSET(zone, free_area);
+        VMCOREINFO_OFFSET(zone, vm_stat);
+        VMCOREINFO_OFFSET(zone, spanned_pages);
+        VMCOREINFO_OFFSET(free_area, free_list);
+        VMCOREINFO_OFFSET(list_head, next);
+        VMCOREINFO_OFFSET(list_head, prev);
+        VMCOREINFO_OFFSET(vmap_area, va_start);
+        VMCOREINFO_OFFSET(vmap_area, list);
+        VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
+        log_buf_kexec_setup();
+        VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
+        VMCOREINFO_NUMBER(NR_FREE_PAGES);
+        VMCOREINFO_NUMBER(PG_lru);
+        VMCOREINFO_NUMBER(PG_private);
+        VMCOREINFO_NUMBER(PG_swapcache);
+        VMCOREINFO_NUMBER(PG_slab);
+#ifdef CONFIG_MEMORY_FAILURE
+        VMCOREINFO_NUMBER(PG_hwpoison);
+#endif
+        VMCOREINFO_NUMBER(PG_head_mask);
+        VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
+#ifdef CONFIG_HUGETLBFS
+        VMCOREINFO_SYMBOL(free_huge_page);
+#endif
+
+        arch_crash_save_vmcoreinfo();
+        update_vmcoreinfo_note();
+
+        return 0;
+}
+
+subsys_initcall(crash_save_vmcoreinfo_init);
+
+/*
+ * Move into place and start executing a preloaded standalone
+ * executable.  If nothing was preloaded return an error.
+ */
+int kernel_kexec(void)
+{
+        int error = 0;
+
+        if (!mutex_trylock(&kexec_mutex))
+                return -EBUSY;
+        if (!kexec_image) {
+                error = -EINVAL;
+                goto Unlock;
+        }
+
+#ifdef CONFIG_KEXEC_JUMP
+        if (kexec_image->preserve_context) {
+                lock_system_sleep();
+                pm_prepare_console();
+                error = freeze_processes();
+                if (error) {
+                        error = -EBUSY;
+                        goto Restore_console;
+                }
+                suspend_console();
+                error = dpm_suspend_start(PMSG_FREEZE);
+                if (error)
+                        goto Resume_console;
+                /* At this point, dpm_suspend_start() has been called,
+                 * but *not* dpm_suspend_end(). We *must* call
+                 * dpm_suspend_end() now.  Otherwise, drivers for
+                 * some devices (e.g. interrupt controllers) become
+                 * desynchronized with the actual state of the
+                 * hardware at resume time, and evil weirdness ensues.
+                 */
+                error = dpm_suspend_end(PMSG_FREEZE);
+                if (error)
+                        goto Resume_devices;
+                error = disable_nonboot_cpus();
+                if (error)
+                        goto Enable_cpus;
+                local_irq_disable();
+                error = syscore_suspend();
+                if (error)
+                        goto Enable_irqs;
+        } else
+#endif
+        {
+                kexec_in_progress = true;
+                kernel_restart_prepare(NULL);
+                migrate_to_reboot_cpu();
+
+                /*
+                 * migrate_to_reboot_cpu() disables CPU hotplug assuming that
+                 * no further code needs to use CPU hotplug (which is true in
+                 * the reboot case). However, the kexec path depends on using
+                 * CPU hotplug again; so re-enable it here.
+                 */
+                cpu_hotplug_enable();
+                pr_emerg("Starting new kernel\n");
+                machine_shutdown();
+        }
+
+        machine_kexec(kexec_image);
+
+#ifdef CONFIG_KEXEC_JUMP
+        if (kexec_image->preserve_context) {
+                syscore_resume();
+ Enable_irqs:
+                local_irq_enable();
+ Enable_cpus:
+                enable_nonboot_cpus();
+                dpm_resume_start(PMSG_RESTORE);
+ Resume_devices:
+                dpm_resume_end(PMSG_RESTORE);
+ Resume_console:
+                resume_console();
+                thaw_processes();
+ Restore_console:
+                pm_restore_console();
+                unlock_system_sleep();
+        }
+#endif
+
+ Unlock:
+        mutex_unlock(&kexec_mutex);
+        return error;
+}
+
+/*
+ * Add and remove page tables for crashkernel memory
+ *
+ * Provide an empty default implementation here -- architecture
+ * code may override this
+ */
+void __weak crash_map_reserved_pages(void)
+{}
+
+void __weak crash_unmap_reserved_pages(void)
+{}