kexec.c 40.4 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/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>
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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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struct resource crashk_low_res = {
	.name  = "Crash kernel low",
	.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;
		/* 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 */
608 609 610
	kimage_free_page_list(&image->unuseable_pages);

}
611
static void kimage_terminate(struct kimage *image)
612
{
M
Maneesh Soni 已提交
613
	if (*image->entry != 0)
614
		image->entry++;
M
Maneesh Soni 已提交
615

616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638
	*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
639

640 641 642 643
	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
644
			if (ind & IND_INDIRECTION)
645 646 647 648 649 650
				kimage_free_entry(ind);
			/* Save this indirection page until we are
			 * done with it.
			 */
			ind = entry;
		}
M
Maneesh Soni 已提交
651
		else if (entry & IND_SOURCE)
652 653 654
			kimage_free_entry(entry);
	}
	/* Free the final indirection page */
M
Maneesh Soni 已提交
655
	if (ind & IND_INDIRECTION)
656 657 658 659 660 661 662 663 664 665
		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
666 667
static kimage_entry_t *kimage_dst_used(struct kimage *image,
					unsigned long page)
668 669 670 671 672
{
	kimage_entry_t *ptr, entry;
	unsigned long destination = 0;

	for_each_kimage_entry(image, ptr, entry) {
M
Maneesh Soni 已提交
673
		if (entry & IND_DESTINATION)
674 675
			destination = entry & PAGE_MASK;
		else if (entry & IND_SOURCE) {
M
Maneesh Soni 已提交
676
			if (page == destination)
677 678 679 680
				return ptr;
			destination += PAGE_SIZE;
		}
	}
M
Maneesh Soni 已提交
681

682
	return NULL;
683 684
}

M
Maneesh Soni 已提交
685
static struct page *kimage_alloc_page(struct kimage *image,
A
Al Viro 已提交
686
					gfp_t gfp_mask,
M
Maneesh Soni 已提交
687
					unsigned long destination)
688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726
{
	/*
	 * 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
727
		if (!page)
728
			return NULL;
729
		/* If the page cannot be used file it away */
M
Maneesh Soni 已提交
730 731
		if (page_to_pfn(page) >
				(KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
732 733 734 735 736 737 738 739 740 741
			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
742 743
		if (!kimage_is_destination_range(image, addr,
						  addr + PAGE_SIZE))
744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762
			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
763 764
			 * destination page, so return it if it's
			 * gfp_flags honor the ones passed in.
765
			 */
766 767 768 769 770
			if (!(gfp_mask & __GFP_HIGHMEM) &&
			    PageHighMem(old_page)) {
				kimage_free_pages(old_page);
				continue;
			}
771 772 773 774 775 776 777 778 779 780 781
			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
782

783 784 785 786
	return page;
}

static int kimage_load_normal_segment(struct kimage *image,
M
Maneesh Soni 已提交
787
					 struct kexec_segment *segment)
788 789 790 791
{
	unsigned long maddr;
	unsigned long ubytes, mbytes;
	int result;
792
	unsigned char __user *buf;
793 794 795 796 797 798 799 800

	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
801
	if (result < 0)
802
		goto out;
M
Maneesh Soni 已提交
803 804

	while (mbytes) {
805 806 807
		struct page *page;
		char *ptr;
		size_t uchunk, mchunk;
M
Maneesh Soni 已提交
808

809
		page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
810
		if (!page) {
811 812 813
			result  = -ENOMEM;
			goto out;
		}
M
Maneesh Soni 已提交
814 815 816
		result = kimage_add_page(image, page_to_pfn(page)
								<< PAGE_SHIFT);
		if (result < 0)
817
			goto out;
M
Maneesh Soni 已提交
818

819 820
		ptr = kmap(page);
		/* Start with a clear page */
821
		clear_page(ptr);
822 823
		ptr += maddr & ~PAGE_MASK;
		mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
M
Maneesh Soni 已提交
824
		if (mchunk > mbytes)
825
			mchunk = mbytes;
M
Maneesh Soni 已提交
826

827
		uchunk = mchunk;
M
Maneesh Soni 已提交
828
		if (uchunk > ubytes)
829
			uchunk = ubytes;
M
Maneesh Soni 已提交
830

831 832 833
		result = copy_from_user(ptr, buf, uchunk);
		kunmap(page);
		if (result) {
834
			result = -EFAULT;
835 836 837 838 839 840 841
			goto out;
		}
		ubytes -= uchunk;
		maddr  += mchunk;
		buf    += mchunk;
		mbytes -= mchunk;
	}
M
Maneesh Soni 已提交
842
out:
843 844 845 846
	return result;
}

static int kimage_load_crash_segment(struct kimage *image,
M
Maneesh Soni 已提交
847
					struct kexec_segment *segment)
848 849 850 851 852 853 854 855
{
	/* 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;
856
	unsigned char __user *buf;
857 858 859 860 861 862

	result = 0;
	buf = segment->buf;
	ubytes = segment->bufsz;
	mbytes = segment->memsz;
	maddr = segment->mem;
M
Maneesh Soni 已提交
863
	while (mbytes) {
864 865 866
		struct page *page;
		char *ptr;
		size_t uchunk, mchunk;
M
Maneesh Soni 已提交
867

868
		page = pfn_to_page(maddr >> PAGE_SHIFT);
869
		if (!page) {
870 871 872 873 874 875
			result  = -ENOMEM;
			goto out;
		}
		ptr = kmap(page);
		ptr += maddr & ~PAGE_MASK;
		mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
M
Maneesh Soni 已提交
876
		if (mchunk > mbytes)
877
			mchunk = mbytes;
M
Maneesh Soni 已提交
878

879 880 881 882 883 884 885
		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
886
		kexec_flush_icache_page(page);
887 888
		kunmap(page);
		if (result) {
889
			result = -EFAULT;
890 891 892 893 894 895 896
			goto out;
		}
		ubytes -= uchunk;
		maddr  += mchunk;
		buf    += mchunk;
		mbytes -= mchunk;
	}
M
Maneesh Soni 已提交
897
out:
898 899 900 901
	return result;
}

static int kimage_load_segment(struct kimage *image,
M
Maneesh Soni 已提交
902
				struct kexec_segment *segment)
903 904
{
	int result = -ENOMEM;
M
Maneesh Soni 已提交
905 906

	switch (image->type) {
907 908 909 910 911 912 913
	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
914

915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937
	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.
 */
938 939
struct kimage *kexec_image;
struct kimage *kexec_crash_image;
940 941

static DEFINE_MUTEX(kexec_mutex);
942

943 944
SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
		struct kexec_segment __user *, segments, unsigned long, flags)
945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981
{
	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.
	 */
982
	if (!mutex_trylock(&kexec_mutex))
983
		return -EBUSY;
M
Maneesh Soni 已提交
984

985
	dest_image = &kexec_image;
M
Maneesh Soni 已提交
986
	if (flags & KEXEC_ON_CRASH)
987 988 989
		dest_image = &kexec_crash_image;
	if (nr_segments > 0) {
		unsigned long i;
M
Maneesh Soni 已提交
990

991
		/* Loading another kernel to reboot into */
M
Maneesh Soni 已提交
992 993 994
		if ((flags & KEXEC_ON_CRASH) == 0)
			result = kimage_normal_alloc(&image, entry,
							nr_segments, segments);
995 996 997 998 999 1000
		/* 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
1001 1002
			result = kimage_crash_alloc(&image, entry,
						     nr_segments, segments);
1003
			crash_map_reserved_pages();
1004
		}
M
Maneesh Soni 已提交
1005
		if (result)
1006
			goto out;
M
Maneesh Soni 已提交
1007

H
Huang Ying 已提交
1008 1009
		if (flags & KEXEC_PRESERVE_CONTEXT)
			image->preserve_context = 1;
1010
		result = machine_kexec_prepare(image);
M
Maneesh Soni 已提交
1011
		if (result)
1012
			goto out;
M
Maneesh Soni 已提交
1013 1014

		for (i = 0; i < nr_segments; i++) {
1015
			result = kimage_load_segment(image, &image->segment[i]);
M
Maneesh Soni 已提交
1016
			if (result)
1017 1018
				goto out;
		}
1019
		kimage_terminate(image);
1020 1021
		if (flags & KEXEC_ON_CRASH)
			crash_unmap_reserved_pages();
1022 1023 1024 1025
	}
	/* Install the new kernel, and  Uninstall the old */
	image = xchg(dest_image, image);

M
Maneesh Soni 已提交
1026
out:
1027
	mutex_unlock(&kexec_mutex);
1028
	kimage_free(image);
M
Maneesh Soni 已提交
1029

1030 1031 1032
	return result;
}

1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044
/*
 * 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)
{}

1045 1046
#ifdef CONFIG_COMPAT
asmlinkage long compat_sys_kexec_load(unsigned long entry,
M
Maneesh Soni 已提交
1047 1048 1049
				unsigned long nr_segments,
				struct compat_kexec_segment __user *segments,
				unsigned long flags)
1050 1051 1052 1053 1054 1055 1056 1057
{
	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
1058
	if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
1059 1060
		return -EINVAL;

M
Maneesh Soni 已提交
1061
	if (nr_segments > KEXEC_SEGMENT_MAX)
1062 1063 1064 1065 1066
		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
1067
		if (result)
1068 1069 1070 1071 1072 1073 1074 1075
			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
1076
		if (result)
1077 1078 1079 1080 1081 1082 1083
			return -EFAULT;
	}

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

1084
void crash_kexec(struct pt_regs *regs)
1085
{
1086
	/* Take the kexec_mutex here to prevent sys_kexec_load
1087 1088 1089 1090 1091 1092 1093
	 * 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...
	 */
1094
	if (mutex_trylock(&kexec_mutex)) {
1095
		if (kexec_crash_image) {
1096
			struct pt_regs fixed_regs;
1097

1098
			crash_setup_regs(&fixed_regs, regs);
K
Ken'ichi Ohmichi 已提交
1099
			crash_save_vmcoreinfo();
1100
			machine_crash_shutdown(&fixed_regs);
1101
			machine_kexec(kexec_crash_image);
1102
		}
1103
		mutex_unlock(&kexec_mutex);
1104 1105
	}
}
1106

1107 1108
size_t crash_get_memory_size(void)
{
1109
	size_t size = 0;
1110
	mutex_lock(&kexec_mutex);
1111
	if (crashk_res.end != crashk_res.start)
1112
		size = resource_size(&crashk_res);
1113 1114 1115 1116
	mutex_unlock(&kexec_mutex);
	return size;
}

1117 1118
void __weak crash_free_reserved_phys_range(unsigned long begin,
					   unsigned long end)
1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133
{
	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;
1134
	unsigned long old_size;
1135
	struct resource *ram_res;
1136 1137 1138 1139 1140 1141 1142 1143 1144

	mutex_lock(&kexec_mutex);

	if (kexec_crash_image) {
		ret = -ENOENT;
		goto unlock;
	}
	start = crashk_res.start;
	end = crashk_res.end;
1145 1146 1147
	old_size = (end == 0) ? 0 : end - start + 1;
	if (new_size >= old_size) {
		ret = (new_size == old_size) ? 0 : -EINVAL;
1148 1149 1150
		goto unlock;
	}

1151 1152 1153 1154 1155 1156
	ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
	if (!ram_res) {
		ret = -ENOMEM;
		goto unlock;
	}

1157 1158
	start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
	end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
1159

1160
	crash_map_reserved_pages();
1161
	crash_free_reserved_phys_range(end, crashk_res.end);
1162

1163
	if ((start == end) && (crashk_res.parent != NULL))
1164
		release_resource(&crashk_res);
1165 1166 1167 1168 1169 1170

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

1171
	crashk_res.end = end - 1;
1172 1173

	insert_resource(&iomem_resource, ram_res);
1174
	crash_unmap_reserved_pages();
1175 1176 1177 1178 1179 1180

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

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
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;

1214
	if ((cpu < 0) || (cpu >= nr_cpu_ids))
1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228
		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);
1230 1231
	buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
		      	      &prstatus, sizeof(prstatus));
1232 1233 1234
	final_note(buf);
}

1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246
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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Ken'ichi Ohmichi 已提交
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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 ? */
1320
		if (system_ram >= start && system_ram < end) {
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1321 1322 1323 1324 1325 1326
			*crash_size = size;
			break;
		}
	} while (*cur++ == ',');

	if (*crash_size > 0) {
1327
		while (*cur && *cur != ' ' && *cur != '@')
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			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);
1364 1365 1366 1367
	else if (*cur != ' ' && *cur != '\0') {
		pr_warning("crashkernel: unrecognized char\n");
		return -EINVAL;
	}
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	return 0;
}

/*
 * That function is the entry point for command line parsing and should be
 * called from the arch-specific code.
 */
1376
static int __init __parse_crashkernel(char *cmdline,
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			     unsigned long long system_ram,
			     unsigned long long *crash_size,
1379 1380
			     unsigned long long *crash_base,
				const char *name)
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{
	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 */
1390
	p = strstr(p, name);
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Bernhard Walle 已提交
1391 1392
	while (p) {
		ck_cmdline = p;
1393
		p = strstr(p+1, name);
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1394 1395 1396 1397 1398
	}

	if (!ck_cmdline)
		return -EINVAL;

1399
	ck_cmdline += strlen(name);
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	/*
	 * 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;
}

1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433
int __init parse_crashkernel(char *cmdline,
			     unsigned long long system_ram,
			     unsigned long long *crash_size,
			     unsigned long long *crash_base)
{
	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
					"crashkernel=");
}

int __init parse_crashkernel_low(char *cmdline,
			     unsigned long long system_ram,
			     unsigned long long *crash_size,
			     unsigned long long *crash_base)
{
	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
					"crashkernel_low=");
}
B
Bernhard Walle 已提交
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1435
static void update_vmcoreinfo_note(void)
K
Ken'ichi Ohmichi 已提交
1436
{
1437
	u32 *buf = vmcoreinfo_note;
K
Ken'ichi Ohmichi 已提交
1438 1439 1440 1441 1442 1443 1444 1445

	if (!vmcoreinfo_size)
		return;
	buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
			      vmcoreinfo_size);
	final_note(buf);
}

1446 1447
void crash_save_vmcoreinfo(void)
{
1448
	vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
1449 1450 1451
	update_vmcoreinfo_note();
}

K
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1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483
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)
{
1484 1485
	VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
	VMCOREINFO_PAGESIZE(PAGE_SIZE);
K
Ken'ichi Ohmichi 已提交
1486

1487 1488
	VMCOREINFO_SYMBOL(init_uts_ns);
	VMCOREINFO_SYMBOL(node_online_map);
1489
#ifdef CONFIG_MMU
1490
	VMCOREINFO_SYMBOL(swapper_pg_dir);
1491
#endif
1492
	VMCOREINFO_SYMBOL(_stext);
1493
	VMCOREINFO_SYMBOL(vmlist);
K
Ken'ichi Ohmichi 已提交
1494 1495

#ifndef CONFIG_NEED_MULTIPLE_NODES
1496 1497
	VMCOREINFO_SYMBOL(mem_map);
	VMCOREINFO_SYMBOL(contig_page_data);
K
Ken'ichi Ohmichi 已提交
1498 1499
#endif
#ifdef CONFIG_SPARSEMEM
1500 1501
	VMCOREINFO_SYMBOL(mem_section);
	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
1502
	VMCOREINFO_STRUCT_SIZE(mem_section);
1503
	VMCOREINFO_OFFSET(mem_section, section_mem_map);
K
Ken'ichi Ohmichi 已提交
1504
#endif
1505 1506 1507 1508 1509 1510
	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);
1511 1512 1513 1514
	VMCOREINFO_OFFSET(page, flags);
	VMCOREINFO_OFFSET(page, _count);
	VMCOREINFO_OFFSET(page, mapping);
	VMCOREINFO_OFFSET(page, lru);
1515 1516
	VMCOREINFO_OFFSET(page, _mapcount);
	VMCOREINFO_OFFSET(page, private);
1517 1518
	VMCOREINFO_OFFSET(pglist_data, node_zones);
	VMCOREINFO_OFFSET(pglist_data, nr_zones);
K
Ken'ichi Ohmichi 已提交
1519
#ifdef CONFIG_FLAT_NODE_MEM_MAP
1520
	VMCOREINFO_OFFSET(pglist_data, node_mem_map);
K
Ken'ichi Ohmichi 已提交
1521
#endif
1522 1523 1524 1525 1526 1527 1528 1529 1530
	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);
1531
	VMCOREINFO_OFFSET(vm_struct, addr);
1532
	VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
1533
	log_buf_kexec_setup();
1534
	VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
1535
	VMCOREINFO_NUMBER(NR_FREE_PAGES);
1536 1537 1538
	VMCOREINFO_NUMBER(PG_lru);
	VMCOREINFO_NUMBER(PG_private);
	VMCOREINFO_NUMBER(PG_swapcache);
1539 1540
	VMCOREINFO_NUMBER(PG_slab);
	VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
K
Ken'ichi Ohmichi 已提交
1541 1542

	arch_crash_save_vmcoreinfo();
1543
	update_vmcoreinfo_note();
K
Ken'ichi Ohmichi 已提交
1544 1545 1546 1547 1548

	return 0;
}

module_init(crash_save_vmcoreinfo_init)
H
Huang Ying 已提交
1549

1550 1551 1552
/*
 * Move into place and start executing a preloaded standalone
 * executable.  If nothing was preloaded return an error.
H
Huang Ying 已提交
1553 1554 1555 1556 1557
 */
int kernel_kexec(void)
{
	int error = 0;

1558
	if (!mutex_trylock(&kexec_mutex))
H
Huang Ying 已提交
1559 1560 1561 1562 1563 1564 1565
		return -EBUSY;
	if (!kexec_image) {
		error = -EINVAL;
		goto Unlock;
	}

#ifdef CONFIG_KEXEC_JUMP
1566
	if (kexec_image->preserve_context) {
1567
		lock_system_sleep();
1568 1569 1570 1571 1572 1573 1574
		pm_prepare_console();
		error = freeze_processes();
		if (error) {
			error = -EBUSY;
			goto Restore_console;
		}
		suspend_console();
1575
		error = dpm_suspend_start(PMSG_FREEZE);
1576 1577
		if (error)
			goto Resume_console;
1578
		/* At this point, dpm_suspend_start() has been called,
1579 1580
		 * but *not* dpm_suspend_end(). We *must* call
		 * dpm_suspend_end() now.  Otherwise, drivers for
1581 1582 1583 1584
		 * some devices (e.g. interrupt controllers) become
		 * desynchronized with the actual state of the
		 * hardware at resume time, and evil weirdness ensues.
		 */
1585
		error = dpm_suspend_end(PMSG_FREEZE);
1586
		if (error)
1587 1588 1589 1590
			goto Resume_devices;
		error = disable_nonboot_cpus();
		if (error)
			goto Enable_cpus;
1591
		local_irq_disable();
1592
		error = syscore_suspend();
1593
		if (error)
1594
			goto Enable_irqs;
1595
	} else
H
Huang Ying 已提交
1596
#endif
1597
	{
1598
		kernel_restart_prepare(NULL);
H
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1599 1600 1601 1602 1603 1604 1605
		printk(KERN_EMERG "Starting new kernel\n");
		machine_shutdown();
	}

	machine_kexec(kexec_image);

#ifdef CONFIG_KEXEC_JUMP
1606
	if (kexec_image->preserve_context) {
1607
		syscore_resume();
1608
 Enable_irqs:
H
Huang Ying 已提交
1609
		local_irq_enable();
1610
 Enable_cpus:
1611
		enable_nonboot_cpus();
1612
		dpm_resume_start(PMSG_RESTORE);
1613
 Resume_devices:
1614
		dpm_resume_end(PMSG_RESTORE);
1615 1616 1617 1618 1619
 Resume_console:
		resume_console();
		thaw_processes();
 Restore_console:
		pm_restore_console();
1620
		unlock_system_sleep();
H
Huang Ying 已提交
1621
	}
1622
#endif
H
Huang Ying 已提交
1623 1624

 Unlock:
1625
	mutex_unlock(&kexec_mutex);
H
Huang Ying 已提交
1626 1627
	return error;
}