kexec.c 37.4 KB
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/*
 * kexec.c - kexec system call
 * 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.
 */

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#include <linux/capability.h>
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#include <linux/mm.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/kexec.h>
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#include <linux/mutex.h>
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#include <linux/list.h>
#include <linux/highmem.h>
#include <linux/syscalls.h>
#include <linux/reboot.h>
#include <linux/ioport.h>
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#include <linux/hardirq.h>
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#include <linux/elf.h>
#include <linux/elfcore.h>
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#include <linux/utsrelease.h>
#include <linux/utsname.h>
#include <linux/numa.h>
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#include <linux/suspend.h>
#include <linux/device.h>
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#include <linux/freezer.h>
#include <linux/pm.h>
#include <linux/cpu.h>
#include <linux/console.h>
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#include <linux/vmalloc.h>
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#include <asm/page.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/system.h>
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#include <asm/sections.h>
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/* Per cpu memory for storing cpu states in case of system crash. */
note_buf_t* crash_notes;

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/* vmcoreinfo stuff */
unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
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size_t vmcoreinfo_size;
size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
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/* 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
};

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int kexec_should_crash(struct task_struct *p)
{
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	if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)
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		return 1;
	return 0;
}

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/*
 * 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
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 * is given by KEXEC_CONTROL_PAGE_SIZE.  In the best case only a single
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 * 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)

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static int kimage_is_destination_range(struct kimage *image,
				       unsigned long start, unsigned long end);
static struct page *kimage_alloc_page(struct kimage *image,
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				       gfp_t gfp_mask,
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				       unsigned long dest);
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static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
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	                    unsigned long nr_segments,
                            struct kexec_segment __user *segments)
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{
	size_t segment_bytes;
	struct kimage *image;
	unsigned long i;
	int result;

	/* Allocate a controlling structure */
	result = -ENOMEM;
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	image = kzalloc(sizeof(*image), GFP_KERNEL);
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	if (!image)
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		goto out;
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	image->head = 0;
	image->entry = &image->head;
	image->last_entry = &image->head;
	image->control_page = ~0; /* By default this does not apply */
	image->start = entry;
	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 unuseable pages */
	INIT_LIST_HEAD(&image->unuseable_pages);

	/* Read in the segments */
	image->nr_segments = nr_segments;
	segment_bytes = nr_segments * sizeof(*segments);
	result = copy_from_user(image->segment, segments, segment_bytes);
	if (result)
		goto out;

	/*
	 * 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 addreses 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;
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		mstart = image->segment[i].mem;
		mend   = mstart + image->segment[i].memsz;
		if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
			goto out;
		if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
			goto out;
	}

	/* 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;
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	for (i = 0; i < nr_segments; i++) {
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		unsigned long mstart, mend;
		unsigned long j;
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		mstart = image->segment[i].mem;
		mend   = mstart + image->segment[i].memsz;
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		for (j = 0; j < i; j++) {
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			unsigned long pstart, pend;
			pstart = image->segment[j].mem;
			pend   = pstart + image->segment[j].memsz;
			/* Do the segments overlap ? */
			if ((mend > pstart) && (mstart < pend))
				goto out;
		}
	}

	/* 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;
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	for (i = 0; i < nr_segments; i++) {
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		if (image->segment[i].bufsz > image->segment[i].memsz)
			goto out;
	}

	result = 0;
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out:
	if (result == 0)
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		*rimage = image;
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	else
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		kfree(image);
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	return result;

}

static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
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				unsigned long nr_segments,
				struct kexec_segment __user *segments)
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{
	int result;
	struct kimage *image;

	/* Allocate and initialize a controlling structure */
	image = NULL;
	result = do_kimage_alloc(&image, entry, nr_segments, segments);
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	if (result)
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		goto out;
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	*rimage = image;

	/*
	 * Find a location for the control code buffer, and add it
	 * the vector of segments so that it's pages will also be
	 * counted as destination pages.
	 */
	result = -ENOMEM;
	image->control_code_page = kimage_alloc_control_pages(image,
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					   get_order(KEXEC_CONTROL_PAGE_SIZE));
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	if (!image->control_code_page) {
		printk(KERN_ERR "Could not allocate control_code_buffer\n");
		goto out;
	}

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	image->swap_page = kimage_alloc_control_pages(image, 0);
	if (!image->swap_page) {
		printk(KERN_ERR "Could not allocate swap buffer\n");
		goto out;
	}

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	result = 0;
 out:
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	if (result == 0)
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		*rimage = image;
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	else
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		kfree(image);
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	return result;
}

static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
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				unsigned long nr_segments,
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				struct kexec_segment __user *segments)
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{
	int result;
	struct kimage *image;
	unsigned long i;

	image = NULL;
	/* Verify we have a valid entry point */
	if ((entry < crashk_res.start) || (entry > crashk_res.end)) {
		result = -EADDRNOTAVAIL;
		goto out;
	}

	/* Allocate and initialize a controlling structure */
	result = do_kimage_alloc(&image, entry, nr_segments, segments);
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	if (result)
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		goto out;

	/* Enable the special crash kernel control page
	 * allocation policy.
	 */
	image->control_page = crashk_res.start;
	image->type = KEXEC_TYPE_CRASH;

	/*
	 * 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.
	 */
	result = -EADDRNOTAVAIL;
	for (i = 0; i < nr_segments; i++) {
		unsigned long mstart, mend;
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		mstart = image->segment[i].mem;
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		mend = mstart + image->segment[i].memsz - 1;
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		/* Ensure we are within the crash kernel limits */
		if ((mstart < crashk_res.start) || (mend > crashk_res.end))
			goto out;
	}

	/*
	 * Find a location for the control code buffer, and add
	 * the vector of segments so that it's pages will also be
	 * counted as destination pages.
	 */
	result = -ENOMEM;
	image->control_code_page = kimage_alloc_control_pages(image,
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					   get_order(KEXEC_CONTROL_PAGE_SIZE));
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	if (!image->control_code_page) {
		printk(KERN_ERR "Could not allocate control_code_buffer\n");
		goto out;
	}

	result = 0;
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out:
	if (result == 0)
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		*rimage = image;
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	else
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		kfree(image);
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	return result;
}

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static int kimage_is_destination_range(struct kimage *image,
					unsigned long start,
					unsigned long end)
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{
	unsigned long i;

	for (i = 0; i < image->nr_segments; i++) {
		unsigned long mstart, mend;
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		mstart = image->segment[i].mem;
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		mend = mstart + image->segment[i].memsz;
		if ((end > mstart) && (start < mend))
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			return 1;
	}
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	return 0;
}

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static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
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{
	struct page *pages;
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	pages = alloc_pages(gfp_mask, order);
	if (pages) {
		unsigned int count, i;
		pages->mapping = NULL;
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		set_page_private(pages, order);
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		count = 1 << order;
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		for (i = 0; i < count; i++)
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			SetPageReserved(pages + i);
	}
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	return pages;
}

static void kimage_free_pages(struct page *page)
{
	unsigned int order, count, i;
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	order = page_private(page);
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	count = 1 << order;
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	for (i = 0; i < count; i++)
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		ClearPageReserved(page + i);
	__free_pages(page, order);
}

static void kimage_free_page_list(struct list_head *list)
{
	struct list_head *pos, *next;
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	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);
	}
}

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static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
							unsigned int order)
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{
	/* 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;
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		pages = kimage_alloc_pages(GFP_KERNEL, 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)) ||
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			      kimage_is_destination_range(image, addr, eaddr)) {
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			list_add(&pages->lru, &extra_pages);
			pages = NULL;
		}
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	} while (!pages);

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	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 everyting to image->dest_pages.
	 *
	 * For now it is simpler to just free the pages.
	 */
	kimage_free_page_list(&extra_pages);

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	return pages;
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}

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static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
						      unsigned int order)
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{
	/* 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;
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	pages = NULL;
	size = (1 << order) << PAGE_SHIFT;
	hole_start = (image->control_page + (size - 1)) & ~(size - 1);
	hole_end   = hole_start + size - 1;
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	while (hole_end <= crashk_res.end) {
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		unsigned long i;
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		if (hole_end > KEXEC_CONTROL_MEMORY_LIMIT)
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			break;
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		if (hole_end > crashk_res.end)
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			break;
		/* See if I overlap any of the segments */
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		for (i = 0; i < image->nr_segments; i++) {
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			unsigned long mstart, mend;
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			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;
		}
	}
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	if (pages)
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		image->control_page = hole_end;
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	return pages;
}


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struct page *kimage_alloc_control_pages(struct kimage *image,
					 unsigned int order)
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{
	struct page *pages = NULL;
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	switch (image->type) {
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	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;
	}
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	return pages;
}

static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
{
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	if (*image->entry != 0)
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		image->entry++;
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	if (image->entry == image->last_entry) {
		kimage_entry_t *ind_page;
		struct page *page;
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		page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
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		if (!page)
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			return -ENOMEM;
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		ind_page = page_address(page);
		*image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
		image->entry = ind_page;
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		image->last_entry = ind_page +
				      ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
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	}
	*image->entry = entry;
	image->entry++;
	*image->entry = 0;
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	return 0;
}

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static int kimage_set_destination(struct kimage *image,
				   unsigned long destination)
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{
	int result;

	destination &= PAGE_MASK;
	result = kimage_add_entry(image, destination | IND_DESTINATION);
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	if (result == 0)
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		image->destination = destination;
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	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);
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	if (result == 0)
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		image->destination += PAGE_SIZE;
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	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 unuseable pages I have cached */
	kimage_free_page_list(&image->unuseable_pages);

}
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static void kimage_terminate(struct kimage *image)
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{
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	if (*image->entry != 0)
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		image->entry++;
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	*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);
}

static void kimage_free(struct kimage *image)
{
	kimage_entry_t *ptr, entry;
	kimage_entry_t ind = 0;

	if (!image)
		return;
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Maneesh Soni 已提交
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634 635 636 637
	kimage_free_extra_pages(image);
	for_each_kimage_entry(image, ptr, entry) {
		if (entry & IND_INDIRECTION) {
			/* Free the previous indirection page */
M
Maneesh Soni 已提交
638
			if (ind & IND_INDIRECTION)
639 640 641 642 643 644
				kimage_free_entry(ind);
			/* Save this indirection page until we are
			 * done with it.
			 */
			ind = entry;
		}
M
Maneesh Soni 已提交
645
		else if (entry & IND_SOURCE)
646 647 648
			kimage_free_entry(entry);
	}
	/* Free the final indirection page */
M
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649
	if (ind & IND_INDIRECTION)
650 651 652 653 654 655 656 657 658 659
		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);
	kfree(image);
}

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Maneesh Soni 已提交
660 661
static kimage_entry_t *kimage_dst_used(struct kimage *image,
					unsigned long page)
662 663 664 665 666
{
	kimage_entry_t *ptr, entry;
	unsigned long destination = 0;

	for_each_kimage_entry(image, ptr, entry) {
M
Maneesh Soni 已提交
667
		if (entry & IND_DESTINATION)
668 669
			destination = entry & PAGE_MASK;
		else if (entry & IND_SOURCE) {
M
Maneesh Soni 已提交
670
			if (page == destination)
671 672 673 674
				return ptr;
			destination += PAGE_SIZE;
		}
	}
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675

676
	return NULL;
677 678
}

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679
static struct page *kimage_alloc_page(struct kimage *image,
A
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680
					gfp_t gfp_mask,
M
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681
					unsigned long destination)
682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720
{
	/*
	 * 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);
M
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721
		if (!page)
722
			return NULL;
723
		/* If the page cannot be used file it away */
M
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724 725
		if (page_to_pfn(page) >
				(KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
726 727 728 729 730 731 732 733 734 735
			list_add(&page->lru, &image->unuseable_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 */
M
Maneesh Soni 已提交
736 737
		if (!kimage_is_destination_range(image, addr,
						  addr + PAGE_SIZE))
738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756
			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
757 758
			 * destination page, so return it if it's
			 * gfp_flags honor the ones passed in.
759
			 */
760 761 762 763 764
			if (!(gfp_mask & __GFP_HIGHMEM) &&
			    PageHighMem(old_page)) {
				kimage_free_pages(old_page);
				continue;
			}
765 766 767 768 769 770 771 772 773 774 775
			addr = old_addr;
			page = old_page;
			break;
		}
		else {
			/* Place the page on the destination list I
			 * will use it later.
			 */
			list_add(&page->lru, &image->dest_pages);
		}
	}
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777 778 779 780
	return page;
}

static int kimage_load_normal_segment(struct kimage *image,
M
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781
					 struct kexec_segment *segment)
782 783 784 785
{
	unsigned long maddr;
	unsigned long ubytes, mbytes;
	int result;
786
	unsigned char __user *buf;
787 788 789 790 791 792 793 794

	result = 0;
	buf = segment->buf;
	ubytes = segment->bufsz;
	mbytes = segment->memsz;
	maddr = segment->mem;

	result = kimage_set_destination(image, maddr);
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795
	if (result < 0)
796
		goto out;
M
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797 798

	while (mbytes) {
799 800 801
		struct page *page;
		char *ptr;
		size_t uchunk, mchunk;
M
Maneesh Soni 已提交
802

803
		page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
804
		if (!page) {
805 806 807
			result  = -ENOMEM;
			goto out;
		}
M
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808 809 810
		result = kimage_add_page(image, page_to_pfn(page)
								<< PAGE_SHIFT);
		if (result < 0)
811
			goto out;
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813 814 815 816 817
		ptr = kmap(page);
		/* Start with a clear page */
		memset(ptr, 0, PAGE_SIZE);
		ptr += maddr & ~PAGE_MASK;
		mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
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818
		if (mchunk > mbytes)
819
			mchunk = mbytes;
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821
		uchunk = mchunk;
M
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822
		if (uchunk > ubytes)
823
			uchunk = ubytes;
M
Maneesh Soni 已提交
824

825 826 827 828 829 830 831 832 833 834 835
		result = copy_from_user(ptr, buf, uchunk);
		kunmap(page);
		if (result) {
			result = (result < 0) ? result : -EIO;
			goto out;
		}
		ubytes -= uchunk;
		maddr  += mchunk;
		buf    += mchunk;
		mbytes -= mchunk;
	}
M
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836
out:
837 838 839 840
	return result;
}

static int kimage_load_crash_segment(struct kimage *image,
M
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841
					struct kexec_segment *segment)
842 843 844 845 846 847 848 849
{
	/* 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;
	unsigned long ubytes, mbytes;
	int result;
850
	unsigned char __user *buf;
851 852 853 854 855 856

	result = 0;
	buf = segment->buf;
	ubytes = segment->bufsz;
	mbytes = segment->memsz;
	maddr = segment->mem;
M
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857
	while (mbytes) {
858 859 860
		struct page *page;
		char *ptr;
		size_t uchunk, mchunk;
M
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861

862
		page = pfn_to_page(maddr >> PAGE_SHIFT);
863
		if (!page) {
864 865 866 867 868 869
			result  = -ENOMEM;
			goto out;
		}
		ptr = kmap(page);
		ptr += maddr & ~PAGE_MASK;
		mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
M
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870
		if (mchunk > mbytes)
871
			mchunk = mbytes;
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872

873 874 875 876 877 878 879
		uchunk = mchunk;
		if (uchunk > ubytes) {
			uchunk = ubytes;
			/* Zero the trailing part of the page */
			memset(ptr + uchunk, 0, mchunk - uchunk);
		}
		result = copy_from_user(ptr, buf, uchunk);
Z
Zou Nan hai 已提交
880
		kexec_flush_icache_page(page);
881 882 883 884 885 886 887 888 889 890
		kunmap(page);
		if (result) {
			result = (result < 0) ? result : -EIO;
			goto out;
		}
		ubytes -= uchunk;
		maddr  += mchunk;
		buf    += mchunk;
		mbytes -= mchunk;
	}
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out:
892 893 894 895
	return result;
}

static int kimage_load_segment(struct kimage *image,
M
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896
				struct kexec_segment *segment)
897 898
{
	int result = -ENOMEM;
M
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899 900

	switch (image->type) {
901 902 903 904 905 906 907
	case KEXEC_TYPE_DEFAULT:
		result = kimage_load_normal_segment(image, segment);
		break;
	case KEXEC_TYPE_CRASH:
		result = kimage_load_crash_segment(image, segment);
		break;
	}
M
Maneesh Soni 已提交
908

909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931
	return result;
}

/*
 * Exec Kernel system call: for obvious reasons only root may call it.
 *
 * This call breaks up into three pieces.
 * - A generic part which loads the new kernel from the current
 *   address space, and very carefully places the data in the
 *   allocated pages.
 *
 * - A generic part that interacts with the kernel and tells all of
 *   the devices to shut down.  Preventing on-going dmas, and placing
 *   the devices in a consistent state so a later kernel can
 *   reinitialize them.
 *
 * - A machine specific part that includes the syscall number
 *   and the copies the image to it's final destination.  And
 *   jumps into the image at entry.
 *
 * kexec does not sync, or unmount filesystems so if you need
 * that to happen you need to do that yourself.
 */
932 933
struct kimage *kexec_image;
struct kimage *kexec_crash_image;
934 935

static DEFINE_MUTEX(kexec_mutex);
936

937 938
SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
		struct kexec_segment __user *, segments, unsigned long, flags)
939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975
{
	struct kimage **dest_image, *image;
	int result;

	/* We only trust the superuser with rebooting the system. */
	if (!capable(CAP_SYS_BOOT))
		return -EPERM;

	/*
	 * Verify we have a legal set of flags
	 * This leaves us room for future extensions.
	 */
	if ((flags & KEXEC_FLAGS) != (flags & ~KEXEC_ARCH_MASK))
		return -EINVAL;

	/* Verify we are on the appropriate architecture */
	if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) &&
		((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
		return -EINVAL;

	/* Put an artificial cap on the number
	 * of segments passed to kexec_load.
	 */
	if (nr_segments > KEXEC_SEGMENT_MAX)
		return -EINVAL;

	image = NULL;
	result = 0;

	/* Because we write directly to the reserved memory
	 * region when loading crash kernels we need a mutex here to
	 * prevent multiple crash  kernels from attempting to load
	 * simultaneously, and to prevent a crash kernel from loading
	 * over the top of a in use crash kernel.
	 *
	 * KISS: always take the mutex.
	 */
976
	if (!mutex_trylock(&kexec_mutex))
977
		return -EBUSY;
M
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978

979
	dest_image = &kexec_image;
M
Maneesh Soni 已提交
980
	if (flags & KEXEC_ON_CRASH)
981 982 983
		dest_image = &kexec_crash_image;
	if (nr_segments > 0) {
		unsigned long i;
M
Maneesh Soni 已提交
984

985
		/* Loading another kernel to reboot into */
M
Maneesh Soni 已提交
986 987 988
		if ((flags & KEXEC_ON_CRASH) == 0)
			result = kimage_normal_alloc(&image, entry,
							nr_segments, segments);
989 990 991 992 993 994
		/* Loading another kernel to switch to if this one crashes */
		else if (flags & KEXEC_ON_CRASH) {
			/* Free any current crash dump kernel before
			 * we corrupt it.
			 */
			kimage_free(xchg(&kexec_crash_image, NULL));
M
Maneesh Soni 已提交
995 996
			result = kimage_crash_alloc(&image, entry,
						     nr_segments, segments);
997
		}
M
Maneesh Soni 已提交
998
		if (result)
999
			goto out;
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Maneesh Soni 已提交
1000

H
Huang Ying 已提交
1001 1002
		if (flags & KEXEC_PRESERVE_CONTEXT)
			image->preserve_context = 1;
1003
		result = machine_kexec_prepare(image);
M
Maneesh Soni 已提交
1004
		if (result)
1005
			goto out;
M
Maneesh Soni 已提交
1006 1007

		for (i = 0; i < nr_segments; i++) {
1008
			result = kimage_load_segment(image, &image->segment[i]);
M
Maneesh Soni 已提交
1009
			if (result)
1010 1011
				goto out;
		}
1012
		kimage_terminate(image);
1013 1014 1015 1016
	}
	/* Install the new kernel, and  Uninstall the old */
	image = xchg(dest_image, image);

M
Maneesh Soni 已提交
1017
out:
1018
	mutex_unlock(&kexec_mutex);
1019
	kimage_free(image);
M
Maneesh Soni 已提交
1020

1021 1022 1023 1024 1025
	return result;
}

#ifdef CONFIG_COMPAT
asmlinkage long compat_sys_kexec_load(unsigned long entry,
M
Maneesh Soni 已提交
1026 1027 1028
				unsigned long nr_segments,
				struct compat_kexec_segment __user *segments,
				unsigned long flags)
1029 1030 1031 1032 1033 1034 1035 1036
{
	struct compat_kexec_segment in;
	struct kexec_segment out, __user *ksegments;
	unsigned long i, result;

	/* Don't allow clients that don't understand the native
	 * architecture to do anything.
	 */
M
Maneesh Soni 已提交
1037
	if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
1038 1039
		return -EINVAL;

M
Maneesh Soni 已提交
1040
	if (nr_segments > KEXEC_SEGMENT_MAX)
1041 1042 1043 1044 1045
		return -EINVAL;

	ksegments = compat_alloc_user_space(nr_segments * sizeof(out));
	for (i=0; i < nr_segments; i++) {
		result = copy_from_user(&in, &segments[i], sizeof(in));
M
Maneesh Soni 已提交
1046
		if (result)
1047 1048 1049 1050 1051 1052 1053 1054
			return -EFAULT;

		out.buf   = compat_ptr(in.buf);
		out.bufsz = in.bufsz;
		out.mem   = in.mem;
		out.memsz = in.memsz;

		result = copy_to_user(&ksegments[i], &out, sizeof(out));
M
Maneesh Soni 已提交
1055
		if (result)
1056 1057 1058 1059 1060 1061 1062
			return -EFAULT;
	}

	return sys_kexec_load(entry, nr_segments, ksegments, flags);
}
#endif

1063
void crash_kexec(struct pt_regs *regs)
1064
{
1065
	/* Take the kexec_mutex here to prevent sys_kexec_load
1066 1067 1068 1069 1070 1071 1072
	 * 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...
	 */
1073
	if (mutex_trylock(&kexec_mutex)) {
1074
		if (kexec_crash_image) {
1075 1076
			struct pt_regs fixed_regs;
			crash_setup_regs(&fixed_regs, regs);
K
Ken'ichi Ohmichi 已提交
1077
			crash_save_vmcoreinfo();
1078
			machine_crash_shutdown(&fixed_regs);
1079
			machine_kexec(kexec_crash_image);
1080
		}
1081
		mutex_unlock(&kexec_mutex);
1082 1083
	}
}
1084

1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117
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;

1118
	if ((cpu < 0) || (cpu >= nr_cpu_ids))
1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133
		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_regs(&prstatus.pr_reg, regs);
1134 1135
	buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
		      	      &prstatus, sizeof(prstatus));
1136 1137 1138
	final_note(buf);
}

1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150
static int __init crash_notes_memory_init(void)
{
	/* Allocate memory for saving cpu registers. */
	crash_notes = alloc_percpu(note_buf_t);
	if (!crash_notes) {
		printk("Kexec: Memory allocation for saving cpu register"
		" states failed\n");
		return -ENOMEM;
	}
	return 0;
}
module_init(crash_notes_memory_init)
K
Ken'ichi Ohmichi 已提交
1151

B
Bernhard Walle 已提交
1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223

/*
 * 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_warning("crashkernel: Memory value expected\n");
			return -EINVAL;
		}
		cur = tmp;
		if (*cur != '-') {
			pr_warning("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_warning("crashkernel: Memory "
						"value expected\n");
				return -EINVAL;
			}
			cur = tmp;
			if (end <= start) {
				pr_warning("crashkernel: end <= start\n");
				return -EINVAL;
			}
		}

		if (*cur != ':') {
			pr_warning("crashkernel: ':' expected\n");
			return -EINVAL;
		}
		cur++;

		size = memparse(cur, &tmp);
		if (cur == tmp) {
			pr_warning("Memory value expected\n");
			return -EINVAL;
		}
		cur = tmp;
		if (size >= system_ram) {
			pr_warning("crashkernel: invalid size\n");
			return -EINVAL;
		}

		/* match ? */
1224
		if (system_ram >= start && system_ram < end) {
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Bernhard Walle 已提交
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			*crash_size = size;
			break;
		}
	} while (*cur++ == ',');

	if (*crash_size > 0) {
		while (*cur != ' ' && *cur != '@')
			cur++;
		if (*cur == '@') {
			cur++;
			*crash_base = memparse(cur, &tmp);
			if (cur == tmp) {
				pr_warning("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_warning("crashkernel: memory value expected\n");
		return -EINVAL;
	}

	if (*cur == '@')
		*crash_base = memparse(cur+1, &cur);

	return 0;
}

/*
 * 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)
{
	char 	*p = cmdline, *ck_cmdline = NULL;
	char	*first_colon, *first_space;

	BUG_ON(!crash_size || !crash_base);
	*crash_size = 0;
	*crash_base = 0;

	/* find crashkernel and use the last one if there are more */
	p = strstr(p, "crashkernel=");
	while (p) {
		ck_cmdline = p;
		p = strstr(p+1, "crashkernel=");
	}

	if (!ck_cmdline)
		return -EINVAL;

	ck_cmdline += 12; /* strlen("crashkernel=") */

	/*
	 * 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);
	else
		return parse_crashkernel_simple(ck_cmdline, crash_size,
				crash_base);

	return 0;
}



K
Ken'ichi Ohmichi 已提交
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void crash_save_vmcoreinfo(void)
{
	u32 *buf;

	if (!vmcoreinfo_size)
		return;

1325
	vmcoreinfo_append_str("CRASHTIME=%ld", get_seconds());
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1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366

	buf = (u32 *)vmcoreinfo_note;

	buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
			      vmcoreinfo_size);

	final_note(buf);
}

void vmcoreinfo_append_str(const char *fmt, ...)
{
	va_list args;
	char buf[0x50];
	int r;

	va_start(args, fmt);
	r = vsnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	if (r + vmcoreinfo_size > vmcoreinfo_max_size)
		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 __attribute__ ((weak)) arch_crash_save_vmcoreinfo(void)
{}

unsigned long __attribute__ ((weak)) paddr_vmcoreinfo_note(void)
{
	return __pa((unsigned long)(char *)&vmcoreinfo_note);
}

static int __init crash_save_vmcoreinfo_init(void)
{
1367 1368
	VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
	VMCOREINFO_PAGESIZE(PAGE_SIZE);
K
Ken'ichi Ohmichi 已提交
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1370 1371 1372 1373
	VMCOREINFO_SYMBOL(init_uts_ns);
	VMCOREINFO_SYMBOL(node_online_map);
	VMCOREINFO_SYMBOL(swapper_pg_dir);
	VMCOREINFO_SYMBOL(_stext);
1374
	VMCOREINFO_SYMBOL(vmlist);
K
Ken'ichi Ohmichi 已提交
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#ifndef CONFIG_NEED_MULTIPLE_NODES
1377 1378
	VMCOREINFO_SYMBOL(mem_map);
	VMCOREINFO_SYMBOL(contig_page_data);
K
Ken'ichi Ohmichi 已提交
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#endif
#ifdef CONFIG_SPARSEMEM
1381 1382
	VMCOREINFO_SYMBOL(mem_section);
	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
1383
	VMCOREINFO_STRUCT_SIZE(mem_section);
1384
	VMCOREINFO_OFFSET(mem_section, section_mem_map);
K
Ken'ichi Ohmichi 已提交
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#endif
1386 1387 1388 1389 1390 1391
	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);
1392 1393 1394 1395 1396 1397
	VMCOREINFO_OFFSET(page, flags);
	VMCOREINFO_OFFSET(page, _count);
	VMCOREINFO_OFFSET(page, mapping);
	VMCOREINFO_OFFSET(page, lru);
	VMCOREINFO_OFFSET(pglist_data, node_zones);
	VMCOREINFO_OFFSET(pglist_data, nr_zones);
K
Ken'ichi Ohmichi 已提交
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#ifdef CONFIG_FLAT_NODE_MEM_MAP
1399
	VMCOREINFO_OFFSET(pglist_data, node_mem_map);
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Ken'ichi Ohmichi 已提交
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#endif
1401 1402 1403 1404 1405 1406 1407 1408 1409
	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);
1410
	VMCOREINFO_OFFSET(vm_struct, addr);
1411
	VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
1412
	VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
1413
	VMCOREINFO_NUMBER(NR_FREE_PAGES);
1414 1415 1416
	VMCOREINFO_NUMBER(PG_lru);
	VMCOREINFO_NUMBER(PG_private);
	VMCOREINFO_NUMBER(PG_swapcache);
K
Ken'ichi Ohmichi 已提交
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	arch_crash_save_vmcoreinfo();

	return 0;
}

module_init(crash_save_vmcoreinfo_init)
H
Huang Ying 已提交
1424

1425 1426 1427
/*
 * Move into place and start executing a preloaded standalone
 * executable.  If nothing was preloaded return an error.
H
Huang Ying 已提交
1428 1429 1430 1431 1432
 */
int kernel_kexec(void)
{
	int error = 0;

1433
	if (!mutex_trylock(&kexec_mutex))
H
Huang Ying 已提交
1434 1435 1436 1437 1438 1439 1440
		return -EBUSY;
	if (!kexec_image) {
		error = -EINVAL;
		goto Unlock;
	}

#ifdef CONFIG_KEXEC_JUMP
1441
	if (kexec_image->preserve_context) {
1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455
		mutex_lock(&pm_mutex);
		pm_prepare_console();
		error = freeze_processes();
		if (error) {
			error = -EBUSY;
			goto Restore_console;
		}
		suspend_console();
		error = device_suspend(PMSG_FREEZE);
		if (error)
			goto Resume_console;
		error = disable_nonboot_cpus();
		if (error)
			goto Resume_devices;
1456
		device_pm_lock();
H
Huang Ying 已提交
1457
		local_irq_disable();
1458 1459 1460 1461 1462 1463 1464 1465 1466 1467
		/* At this point, device_suspend() has been called,
		 * but *not* device_power_down(). We *must*
		 * device_power_down() 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 = device_power_down(PMSG_FREEZE);
		if (error)
			goto Enable_irqs;
1468
	} else
H
Huang Ying 已提交
1469
#endif
1470
	{
1471
		kernel_restart_prepare(NULL);
H
Huang Ying 已提交
1472 1473 1474 1475 1476 1477 1478
		printk(KERN_EMERG "Starting new kernel\n");
		machine_shutdown();
	}

	machine_kexec(kexec_image);

#ifdef CONFIG_KEXEC_JUMP
1479
	if (kexec_image->preserve_context) {
1480 1481
		device_power_up(PMSG_RESTORE);
 Enable_irqs:
H
Huang Ying 已提交
1482
		local_irq_enable();
1483
		device_pm_unlock();
1484 1485 1486 1487 1488 1489 1490 1491 1492
		enable_nonboot_cpus();
 Resume_devices:
		device_resume(PMSG_RESTORE);
 Resume_console:
		resume_console();
		thaw_processes();
 Restore_console:
		pm_restore_console();
		mutex_unlock(&pm_mutex);
H
Huang Ying 已提交
1493
	}
1494
#endif
H
Huang Ying 已提交
1495 1496

 Unlock:
1497
	mutex_unlock(&kexec_mutex);
H
Huang Ying 已提交
1498 1499
	return error;
}