kexec.c 39.5 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 <generated/utsrelease.h>
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#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 <linux/swap.h>
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#include <linux/syscore_ops.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. */
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note_buf_t __percpu *crash_notes;
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/* vmcoreinfo stuff */
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static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
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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);

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	/* Initialize the list of unusable pages */
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	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);
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	if (result) {
		result = -EFAULT;
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		goto out;
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	}
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	/*
	 * 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
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	 * the destination addresses are page aligned.  Too many
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	 * 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
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	 * page allocations, and add everything to image->dest_pages.
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	 *
	 * 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_CRASH_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);

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	/* Walk through and free any unusable pages I have cached */
606 607 608
	kimage_free_page_list(&image->unuseable_pages);

}
609
static void kimage_terminate(struct kimage *image)
610
{
M
Maneesh Soni 已提交
611
	if (*image->entry != 0)
612
		image->entry++;
M
Maneesh Soni 已提交
613

614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636
	*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;
M
Maneesh Soni 已提交
637

638 639 640 641
	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
642
			if (ind & IND_INDIRECTION)
643 644 645 646 647 648
				kimage_free_entry(ind);
			/* Save this indirection page until we are
			 * done with it.
			 */
			ind = entry;
		}
M
Maneesh Soni 已提交
649
		else if (entry & IND_SOURCE)
650 651 652
			kimage_free_entry(entry);
	}
	/* Free the final indirection page */
M
Maneesh Soni 已提交
653
	if (ind & IND_INDIRECTION)
654 655 656 657 658 659 660 661 662 663
		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);
}

M
Maneesh Soni 已提交
664 665
static kimage_entry_t *kimage_dst_used(struct kimage *image,
					unsigned long page)
666 667 668 669 670
{
	kimage_entry_t *ptr, entry;
	unsigned long destination = 0;

	for_each_kimage_entry(image, ptr, entry) {
M
Maneesh Soni 已提交
671
		if (entry & IND_DESTINATION)
672 673
			destination = entry & PAGE_MASK;
		else if (entry & IND_SOURCE) {
M
Maneesh Soni 已提交
674
			if (page == destination)
675 676 677 678
				return ptr;
			destination += PAGE_SIZE;
		}
	}
M
Maneesh Soni 已提交
679

680
	return NULL;
681 682
}

M
Maneesh Soni 已提交
683
static struct page *kimage_alloc_page(struct kimage *image,
A
Al Viro 已提交
684
					gfp_t gfp_mask,
M
Maneesh Soni 已提交
685
					unsigned long destination)
686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724
{
	/*
	 * 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
Maneesh Soni 已提交
725
		if (!page)
726
			return NULL;
727
		/* If the page cannot be used file it away */
M
Maneesh Soni 已提交
728 729
		if (page_to_pfn(page) >
				(KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
730 731 732 733 734 735 736 737 738 739
			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
740 741
		if (!kimage_is_destination_range(image, addr,
						  addr + PAGE_SIZE))
742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760
			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
761 762
			 * destination page, so return it if it's
			 * gfp_flags honor the ones passed in.
763
			 */
764 765 766 767 768
			if (!(gfp_mask & __GFP_HIGHMEM) &&
			    PageHighMem(old_page)) {
				kimage_free_pages(old_page);
				continue;
			}
769 770 771 772 773 774 775 776 777 778 779
			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);
		}
	}
M
Maneesh Soni 已提交
780

781 782 783 784
	return page;
}

static int kimage_load_normal_segment(struct kimage *image,
M
Maneesh Soni 已提交
785
					 struct kexec_segment *segment)
786 787 788 789
{
	unsigned long maddr;
	unsigned long ubytes, mbytes;
	int result;
790
	unsigned char __user *buf;
791 792 793 794 795 796 797 798

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

	result = kimage_set_destination(image, maddr);
M
Maneesh Soni 已提交
799
	if (result < 0)
800
		goto out;
M
Maneesh Soni 已提交
801 802

	while (mbytes) {
803 804 805
		struct page *page;
		char *ptr;
		size_t uchunk, mchunk;
M
Maneesh Soni 已提交
806

807
		page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
808
		if (!page) {
809 810 811
			result  = -ENOMEM;
			goto out;
		}
M
Maneesh Soni 已提交
812 813 814
		result = kimage_add_page(image, page_to_pfn(page)
								<< PAGE_SHIFT);
		if (result < 0)
815
			goto out;
M
Maneesh Soni 已提交
816

817 818
		ptr = kmap(page);
		/* Start with a clear page */
819
		clear_page(ptr);
820 821
		ptr += maddr & ~PAGE_MASK;
		mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
M
Maneesh Soni 已提交
822
		if (mchunk > mbytes)
823
			mchunk = mbytes;
M
Maneesh Soni 已提交
824

825
		uchunk = mchunk;
M
Maneesh Soni 已提交
826
		if (uchunk > ubytes)
827
			uchunk = ubytes;
M
Maneesh Soni 已提交
828

829 830 831
		result = copy_from_user(ptr, buf, uchunk);
		kunmap(page);
		if (result) {
832
			result = -EFAULT;
833 834 835 836 837 838 839
			goto out;
		}
		ubytes -= uchunk;
		maddr  += mchunk;
		buf    += mchunk;
		mbytes -= mchunk;
	}
M
Maneesh Soni 已提交
840
out:
841 842 843 844
	return result;
}

static int kimage_load_crash_segment(struct kimage *image,
M
Maneesh Soni 已提交
845
					struct kexec_segment *segment)
846 847 848 849 850 851 852 853
{
	/* 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;
854
	unsigned char __user *buf;
855 856 857 858 859 860

	result = 0;
	buf = segment->buf;
	ubytes = segment->bufsz;
	mbytes = segment->memsz;
	maddr = segment->mem;
M
Maneesh Soni 已提交
861
	while (mbytes) {
862 863 864
		struct page *page;
		char *ptr;
		size_t uchunk, mchunk;
M
Maneesh Soni 已提交
865

866
		page = pfn_to_page(maddr >> PAGE_SHIFT);
867
		if (!page) {
868 869 870 871 872 873
			result  = -ENOMEM;
			goto out;
		}
		ptr = kmap(page);
		ptr += maddr & ~PAGE_MASK;
		mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
M
Maneesh Soni 已提交
874
		if (mchunk > mbytes)
875
			mchunk = mbytes;
M
Maneesh Soni 已提交
876

877 878 879 880 881 882 883
		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
884
		kexec_flush_icache_page(page);
885 886
		kunmap(page);
		if (result) {
887
			result = -EFAULT;
888 889 890 891 892 893 894
			goto out;
		}
		ubytes -= uchunk;
		maddr  += mchunk;
		buf    += mchunk;
		mbytes -= mchunk;
	}
M
Maneesh Soni 已提交
895
out:
896 897 898 899
	return result;
}

static int kimage_load_segment(struct kimage *image,
M
Maneesh Soni 已提交
900
				struct kexec_segment *segment)
901 902
{
	int result = -ENOMEM;
M
Maneesh Soni 已提交
903 904

	switch (image->type) {
905 906 907 908 909 910 911
	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
912

913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935
	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.
 */
936 937
struct kimage *kexec_image;
struct kimage *kexec_crash_image;
938 939

static DEFINE_MUTEX(kexec_mutex);
940

941 942
SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
		struct kexec_segment __user *, segments, unsigned long, flags)
943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979
{
	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.
	 */
980
	if (!mutex_trylock(&kexec_mutex))
981
		return -EBUSY;
M
Maneesh Soni 已提交
982

983
	dest_image = &kexec_image;
M
Maneesh Soni 已提交
984
	if (flags & KEXEC_ON_CRASH)
985 986 987
		dest_image = &kexec_crash_image;
	if (nr_segments > 0) {
		unsigned long i;
M
Maneesh Soni 已提交
988

989
		/* Loading another kernel to reboot into */
M
Maneesh Soni 已提交
990 991 992
		if ((flags & KEXEC_ON_CRASH) == 0)
			result = kimage_normal_alloc(&image, entry,
							nr_segments, segments);
993 994 995 996 997 998
		/* 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
999 1000
			result = kimage_crash_alloc(&image, entry,
						     nr_segments, segments);
1001
			crash_map_reserved_pages();
1002
		}
M
Maneesh Soni 已提交
1003
		if (result)
1004
			goto out;
M
Maneesh Soni 已提交
1005

H
Huang Ying 已提交
1006 1007
		if (flags & KEXEC_PRESERVE_CONTEXT)
			image->preserve_context = 1;
1008
		result = machine_kexec_prepare(image);
M
Maneesh Soni 已提交
1009
		if (result)
1010
			goto out;
M
Maneesh Soni 已提交
1011 1012

		for (i = 0; i < nr_segments; i++) {
1013
			result = kimage_load_segment(image, &image->segment[i]);
M
Maneesh Soni 已提交
1014
			if (result)
1015 1016
				goto out;
		}
1017
		kimage_terminate(image);
1018 1019
		if (flags & KEXEC_ON_CRASH)
			crash_unmap_reserved_pages();
1020 1021 1022 1023
	}
	/* Install the new kernel, and  Uninstall the old */
	image = xchg(dest_image, image);

M
Maneesh Soni 已提交
1024
out:
1025
	mutex_unlock(&kexec_mutex);
1026
	kimage_free(image);
M
Maneesh Soni 已提交
1027

1028 1029 1030
	return result;
}

1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042
/*
 * 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)
{}

1043 1044
#ifdef CONFIG_COMPAT
asmlinkage long compat_sys_kexec_load(unsigned long entry,
M
Maneesh Soni 已提交
1045 1046 1047
				unsigned long nr_segments,
				struct compat_kexec_segment __user *segments,
				unsigned long flags)
1048 1049 1050 1051 1052 1053 1054 1055
{
	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
1056
	if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
1057 1058
		return -EINVAL;

M
Maneesh Soni 已提交
1059
	if (nr_segments > KEXEC_SEGMENT_MAX)
1060 1061 1062 1063 1064
		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
1065
		if (result)
1066 1067 1068 1069 1070 1071 1072 1073
			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
1074
		if (result)
1075 1076 1077 1078 1079 1080 1081
			return -EFAULT;
	}

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

1082
void crash_kexec(struct pt_regs *regs)
1083
{
1084
	/* Take the kexec_mutex here to prevent sys_kexec_load
1085 1086 1087 1088 1089 1090 1091
	 * 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...
	 */
1092
	if (mutex_trylock(&kexec_mutex)) {
1093
		if (kexec_crash_image) {
1094
			struct pt_regs fixed_regs;
1095

1096
			crash_setup_regs(&fixed_regs, regs);
K
Ken'ichi Ohmichi 已提交
1097
			crash_save_vmcoreinfo();
1098
			machine_crash_shutdown(&fixed_regs);
1099
			machine_kexec(kexec_crash_image);
1100
		}
1101
		mutex_unlock(&kexec_mutex);
1102 1103
	}
}
1104

1105 1106
size_t crash_get_memory_size(void)
{
1107
	size_t size = 0;
1108
	mutex_lock(&kexec_mutex);
1109
	if (crashk_res.end != crashk_res.start)
1110
		size = resource_size(&crashk_res);
1111 1112 1113 1114
	mutex_unlock(&kexec_mutex);
	return size;
}

1115 1116
void __weak crash_free_reserved_phys_range(unsigned long begin,
					   unsigned long end)
1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131
{
	unsigned long addr;

	for (addr = begin; addr < end; addr += PAGE_SIZE) {
		ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
		init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
		free_page((unsigned long)__va(addr));
		totalram_pages++;
	}
}

int crash_shrink_memory(unsigned long new_size)
{
	int ret = 0;
	unsigned long start, end;
1132
	unsigned long old_size;
1133
	struct resource *ram_res;
1134 1135 1136 1137 1138 1139 1140 1141 1142

	mutex_lock(&kexec_mutex);

	if (kexec_crash_image) {
		ret = -ENOENT;
		goto unlock;
	}
	start = crashk_res.start;
	end = crashk_res.end;
1143 1144 1145
	old_size = (end == 0) ? 0 : end - start + 1;
	if (new_size >= old_size) {
		ret = (new_size == old_size) ? 0 : -EINVAL;
1146 1147 1148
		goto unlock;
	}

1149 1150 1151 1152 1153 1154
	ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
	if (!ram_res) {
		ret = -ENOMEM;
		goto unlock;
	}

1155 1156
	start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
	end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
1157

1158
	crash_map_reserved_pages();
1159
	crash_free_reserved_phys_range(end, crashk_res.end);
1160

1161
	if ((start == end) && (crashk_res.parent != NULL))
1162
		release_resource(&crashk_res);
1163 1164 1165 1166 1167 1168

	ram_res->start = end;
	ram_res->end = crashk_res.end;
	ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
	ram_res->name = "System RAM";

1169
	crashk_res.end = end - 1;
1170 1171

	insert_resource(&iomem_resource, ram_res);
1172
	crash_unmap_reserved_pages();
1173 1174 1175 1176 1177 1178

unlock:
	mutex_unlock(&kexec_mutex);
	return ret;
}

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
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;

1212
	if ((cpu < 0) || (cpu >= nr_cpu_ids))
1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226
		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;
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Tejun Heo 已提交
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	elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
1228 1229
	buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
		      	      &prstatus, sizeof(prstatus));
1230 1231 1232
	final_note(buf);
}

1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244
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)
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/*
 * 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 ? */
1318
		if (system_ram >= start && system_ram < end) {
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1319 1320 1321 1322 1323 1324
			*crash_size = size;
			break;
		}
	} while (*cur++ == ',');

	if (*crash_size > 0) {
1325
		while (*cur && *cur != ' ' && *cur != '@')
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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 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410
			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;
}


1411
static void update_vmcoreinfo_note(void)
K
Ken'ichi Ohmichi 已提交
1412
{
1413
	u32 *buf = vmcoreinfo_note;
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	if (!vmcoreinfo_size)
		return;
	buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
			      vmcoreinfo_size);
	final_note(buf);
}

1422 1423 1424 1425 1426 1427
void crash_save_vmcoreinfo(void)
{
	vmcoreinfo_append_str("CRASHTIME=%ld", get_seconds());
	update_vmcoreinfo_note();
}

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1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459
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)
{
1460 1461
	VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
	VMCOREINFO_PAGESIZE(PAGE_SIZE);
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Ken'ichi Ohmichi 已提交
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1463 1464 1465 1466
	VMCOREINFO_SYMBOL(init_uts_ns);
	VMCOREINFO_SYMBOL(node_online_map);
	VMCOREINFO_SYMBOL(swapper_pg_dir);
	VMCOREINFO_SYMBOL(_stext);
1467
	VMCOREINFO_SYMBOL(vmlist);
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Ken'ichi Ohmichi 已提交
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#ifndef CONFIG_NEED_MULTIPLE_NODES
1470 1471
	VMCOREINFO_SYMBOL(mem_map);
	VMCOREINFO_SYMBOL(contig_page_data);
K
Ken'ichi Ohmichi 已提交
1472 1473
#endif
#ifdef CONFIG_SPARSEMEM
1474 1475
	VMCOREINFO_SYMBOL(mem_section);
	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
1476
	VMCOREINFO_STRUCT_SIZE(mem_section);
1477
	VMCOREINFO_OFFSET(mem_section, section_mem_map);
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Ken'ichi Ohmichi 已提交
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#endif
1479 1480 1481 1482 1483 1484
	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);
1485 1486 1487 1488 1489 1490
	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);
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Ken'ichi Ohmichi 已提交
1491
#ifdef CONFIG_FLAT_NODE_MEM_MAP
1492
	VMCOREINFO_OFFSET(pglist_data, node_mem_map);
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Ken'ichi Ohmichi 已提交
1493
#endif
1494 1495 1496 1497 1498 1499 1500 1501 1502
	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);
1503
	VMCOREINFO_OFFSET(vm_struct, addr);
1504
	VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
1505
	log_buf_kexec_setup();
1506
	VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
1507
	VMCOREINFO_NUMBER(NR_FREE_PAGES);
1508 1509 1510
	VMCOREINFO_NUMBER(PG_lru);
	VMCOREINFO_NUMBER(PG_private);
	VMCOREINFO_NUMBER(PG_swapcache);
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Ken'ichi Ohmichi 已提交
1511 1512

	arch_crash_save_vmcoreinfo();
1513
	update_vmcoreinfo_note();
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1514 1515 1516 1517 1518

	return 0;
}

module_init(crash_save_vmcoreinfo_init)
H
Huang Ying 已提交
1519

1520 1521 1522
/*
 * Move into place and start executing a preloaded standalone
 * executable.  If nothing was preloaded return an error.
H
Huang Ying 已提交
1523 1524 1525 1526 1527
 */
int kernel_kexec(void)
{
	int error = 0;

1528
	if (!mutex_trylock(&kexec_mutex))
H
Huang Ying 已提交
1529 1530 1531 1532 1533 1534 1535
		return -EBUSY;
	if (!kexec_image) {
		error = -EINVAL;
		goto Unlock;
	}

#ifdef CONFIG_KEXEC_JUMP
1536
	if (kexec_image->preserve_context) {
1537
		lock_system_sleep();
1538 1539 1540 1541 1542 1543 1544
		pm_prepare_console();
		error = freeze_processes();
		if (error) {
			error = -EBUSY;
			goto Restore_console;
		}
		suspend_console();
1545
		error = dpm_suspend_start(PMSG_FREEZE);
1546 1547
		if (error)
			goto Resume_console;
1548 1549 1550
		/* At this point, dpm_suspend_start() has been called,
		 * but *not* dpm_suspend_noirq(). We *must* call
		 * dpm_suspend_noirq() now.  Otherwise, drivers for
1551 1552 1553 1554
		 * some devices (e.g. interrupt controllers) become
		 * desynchronized with the actual state of the
		 * hardware at resume time, and evil weirdness ensues.
		 */
1555
		error = dpm_suspend_noirq(PMSG_FREEZE);
1556
		if (error)
1557 1558 1559 1560
			goto Resume_devices;
		error = disable_nonboot_cpus();
		if (error)
			goto Enable_cpus;
1561
		local_irq_disable();
1562
		error = syscore_suspend();
1563
		if (error)
1564
			goto Enable_irqs;
1565
	} else
H
Huang Ying 已提交
1566
#endif
1567
	{
1568
		kernel_restart_prepare(NULL);
H
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1569 1570 1571 1572 1573 1574 1575
		printk(KERN_EMERG "Starting new kernel\n");
		machine_shutdown();
	}

	machine_kexec(kexec_image);

#ifdef CONFIG_KEXEC_JUMP
1576
	if (kexec_image->preserve_context) {
1577
		syscore_resume();
1578
 Enable_irqs:
H
Huang Ying 已提交
1579
		local_irq_enable();
1580
 Enable_cpus:
1581
		enable_nonboot_cpus();
1582
		dpm_resume_noirq(PMSG_RESTORE);
1583
 Resume_devices:
1584
		dpm_resume_end(PMSG_RESTORE);
1585 1586 1587 1588 1589
 Resume_console:
		resume_console();
		thaw_processes();
 Restore_console:
		pm_restore_console();
1590
		unlock_system_sleep();
H
Huang Ying 已提交
1591
	}
1592
#endif
H
Huang Ying 已提交
1593 1594

 Unlock:
1595
	mutex_unlock(&kexec_mutex);
H
Huang Ying 已提交
1596 1597
	return error;
}