#include <linux/capability.h>

#include <linux/mm.h>

#include <linux/file.h>

#include <linux/slab.h>

#include <linux/fs.h>

#include <linux/kexec.h>

#include <linux/mutex.h>

#include <linux/list.h>

#include <linux/highmem.h>

#include <linux/syscalls.h>

#include <linux/reboot.h>

#include <linux/ioport.h>

#include <linux/hardirq.h>

#include <linux/elf.h>

#include <linux/elfcore.h>

#include <linux/utsname.h>

#include <linux/numa.h>

#include <linux/suspend.h>

#include <linux/device.h>

#include <linux/freezer.h>

#include <linux/pm.h>

#include <linux/cpu.h>

#include <linux/console.h>

#include <linux/vmalloc.h>

#include <linux/swap.h>

#include <linux/syscore_ops.h>

#include <asm/page.h>

#include <asm/uaccess.h>

#include <asm/io.h>

#include <asm/sections.h>

note_buf_t __percpu *crash_notes;

static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];

u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];

size_t vmcoreinfo_size;

size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);

bool kexec_in_progress = false;

struct resource crashk_res = {

.name = "Crash kernel",

.start = 0,

.end = 0,

.flags = IORESOURCE_BUSY | IORESOURCE_MEM

};

struct resource crashk_low_res = {

.name = "Crash kernel",

.start = 0,

.end = 0,

.flags = IORESOURCE_BUSY | IORESOURCE_MEM

};

int kexec_should_crash(struct task_struct *p)

{

if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)

return 1;

return 0;

}

#define KIMAGE_NO_DEST (-1UL)

static int kimage_is_destination_range(struct kimage *image,

unsigned long start, unsigned long end);

static struct page *kimage_alloc_page(struct kimage *image,

gfp_t gfp_mask,

unsigned long dest);

static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,

unsigned long nr_segments,

struct kexec_segment __user *segments)

{

size_t segment_bytes;

struct kimage *image;

unsigned long i;

int result;

/* Allocate a controlling structure */

result = -ENOMEM;

image = kzalloc(sizeof(*image), GFP_KERNEL);

if (!image)

goto out;

image->head = 0;

image->entry = &image->head;

image->last_entry = &image->head;

image->control_page = ~0; /* By default this does not apply */

image->start = entry;

image->type = KEXEC_TYPE_DEFAULT;

/* Initialize the list of control pages */

INIT_LIST_HEAD(&image->control_pages);

/* Initialize the list of destination pages */

INIT_LIST_HEAD(&image->dest_pages);

/* Initialize the list of unusable pages */

INIT_LIST_HEAD(&image->unuseable_pages);

/* Read in the segments */

image->nr_segments = nr_segments;

segment_bytes = nr_segments * sizeof(*segments);

result = copy_from_user(image->segment, segments, segment_bytes);

if (result) {

result = -EFAULT;

goto out;

}

/*

result = -EADDRNOTAVAIL;

for (i = 0; i < nr_segments; i++) {

unsigned long mstart, mend;

mstart = image->segment[i].mem;

mend = mstart + image->segment[i].memsz;

if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))

goto out;

if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)

goto out;

}

/* Verify our destination addresses do not overlap.

result = -EINVAL;

for (i = 0; i < nr_segments; i++) {

unsigned long mstart, mend;

unsigned long j;

mstart = image->segment[i].mem;

mend = mstart + image->segment[i].memsz;

for (j = 0; j < i; j++) {

unsigned long pstart, pend;

pstart = image->segment[j].mem;

pend = pstart + image->segment[j].memsz;

/* Do the segments overlap ? */

if ((mend > pstart) && (mstart < pend))

goto out;

}

}

/* Ensure our buffer sizes are strictly less than

result = -EINVAL;

for (i = 0; i < nr_segments; i++) {

if (image->segment[i].bufsz > image->segment[i].memsz)

goto out;

}

result = 0;

out:

if (result == 0)

*rimage = image;

else

kfree(image);

return result;

}

static void kimage_free_page_list(struct list_head *list);

static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,

unsigned long nr_segments,

struct kexec_segment __user *segments)

{

int result;

struct kimage *image;

/* Allocate and initialize a controlling structure */

image = NULL;

result = do_kimage_alloc(&image, entry, nr_segments, segments);

if (result)

goto out;

/*

result = -ENOMEM;

image->control_code_page = kimage_alloc_control_pages(image,

get_order(KEXEC_CONTROL_PAGE_SIZE));

if (!image->control_code_page) {

printk(KERN_ERR "Could not allocate control_code_buffer\n");

goto out_free;

}

image->swap_page = kimage_alloc_control_pages(image, 0);

if (!image->swap_page) {

printk(KERN_ERR "Could not allocate swap buffer\n");

goto out_free;

}

*rimage = image;

return 0;

out_free:

kimage_free_page_list(&image->control_pages);

kfree(image);

out:

return result;

}

static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,

unsigned long nr_segments,

struct kexec_segment __user *segments)

{

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);

if (result)

goto out;

/* Enable the special crash kernel control page

image->control_page = crashk_res.start;

image->type = KEXEC_TYPE_CRASH;

/*

result = -EADDRNOTAVAIL;

for (i = 0; i < nr_segments; i++) {

unsigned long mstart, mend;

mstart = image->segment[i].mem;

mend = mstart + image->segment[i].memsz - 1;

/* Ensure we are within the crash kernel limits */

if ((mstart < crashk_res.start) || (mend > crashk_res.end))

goto out_free;

}

/*

result = -ENOMEM;

image->control_code_page = kimage_alloc_control_pages(image,

get_order(KEXEC_CONTROL_PAGE_SIZE));

if (!image->control_code_page) {

printk(KERN_ERR "Could not allocate control_code_buffer\n");

goto out_free;

}

*rimage = image;

return 0;

out_free:

kfree(image);

out:

return result;

}

static int kimage_is_destination_range(struct kimage *image,

unsigned long start,

unsigned long end)

{

unsigned long i;

for (i = 0; i < image->nr_segments; i++) {

unsigned long mstart, mend;

mstart = image->segment[i].mem;

mend = mstart + image->segment[i].memsz;

if ((end > mstart) && (start < mend))

return 1;

}

return 0;

}

static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)

{

struct page *pages;

pages = alloc_pages(gfp_mask, order);

if (pages) {

unsigned int count, i;

pages->mapping = NULL;

set_page_private(pages, order);

count = 1 << order;

for (i = 0; i < count; i++)

SetPageReserved(pages + i);

}

return pages;

}

static void kimage_free_pages(struct page *page)

{

unsigned int order, count, i;

order = page_private(page);

count = 1 << order;

for (i = 0; i < count; i++)

ClearPageReserved(page + i);

__free_pages(page, order);

}

static void kimage_free_page_list(struct list_head *list)

{

struct list_head *pos, *next;

list_for_each_safe(pos, next, list) {

struct page *page;

page = list_entry(pos, struct page, lru);

list_del(&page->lru);

kimage_free_pages(page);

}

}

static struct page *kimage_alloc_normal_control_pages(struct kimage *image,

unsigned int order)

{

/* Control pages are special, they are the intermediaries

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

do {

unsigned long pfn, epfn, addr, eaddr;

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)) ||

kimage_is_destination_range(image, addr, eaddr)) {

list_add(&pages->lru, &extra_pages);

pages = NULL;

}

} while (!pages);

if (pages) {

/* Remember the allocated page... */

list_add(&pages->lru, &image->control_pages);

/* Because the page is already in it's destination

}

/* Deal with the destination pages I have inadvertently allocated.

kimage_free_page_list(&extra_pages);

return pages;

}

static struct page *kimage_alloc_crash_control_pages(struct kimage *image,

unsigned int order)

{

/* Control pages are special, they are the intermediaries

unsigned long hole_start, hole_end, size;

struct page *pages;

pages = NULL;

size = (1 << order) << PAGE_SHIFT;

hole_start = (image->control_page + (size - 1)) & ~(size - 1);

hole_end = hole_start + size - 1;

while (hole_end <= crashk_res.end) {

unsigned long i;

if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)

break;

/* See if I overlap any of the segments */

for (i = 0; i < image->nr_segments; i++) {

unsigned long mstart, mend;

mstart = image->segment[i].mem;

mend = mstart + image->segment[i].memsz - 1;

if ((hole_end >= mstart) && (hole_start <= mend)) {

/* Advance the hole to the end of the segment */

hole_start = (mend + (size - 1)) & ~(size - 1);

hole_end = hole_start + size - 1;

break;

}

}

/* If I don't overlap any segments I have found my hole! */

if (i == image->nr_segments) {

pages = pfn_to_page(hole_start >> PAGE_SHIFT);

break;

}

}

if (pages)

image->control_page = hole_end;

return pages;

}

struct page *kimage_alloc_control_pages(struct kimage *image,

unsigned int order)

{

struct page *pages = NULL;

switch (image->type) {

case KEXEC_TYPE_DEFAULT:

pages = kimage_alloc_normal_control_pages(image, order);

break;

case KEXEC_TYPE_CRASH:

pages = kimage_alloc_crash_control_pages(image, order);

break;

}

return pages;

}

static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)

{

if (*image->entry != 0)

image->entry++;

if (image->entry == image->last_entry) {

kimage_entry_t *ind_page;

struct page *page;

page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);

if (!page)

return -ENOMEM;

ind_page = page_address(page);

*image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;

image->entry = ind_page;

image->last_entry = ind_page +

((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);

}

*image->entry = entry;

image->entry++;

*image->entry = 0;

return 0;

}

static int kimage_set_destination(struct kimage *image,

unsigned long destination)

{

int result;

destination &= PAGE_MASK;

result = kimage_add_entry(image, destination | IND_DESTINATION);

if (result == 0)

image->destination = destination;

return result;

}

static int kimage_add_page(struct kimage *image, unsigned long page)

{

int result;

page &= PAGE_MASK;

result = kimage_add_entry(image, page | IND_SOURCE);

if (result == 0)

image->destination += PAGE_SIZE;

return result;

}

static void kimage_free_extra_pages(struct kimage *image)

{

/* Walk through and free any extra destination pages I may have */

kimage_free_page_list(&image->dest_pages);

/* Walk through and free any unusable pages I have cached */

kimage_free_page_list(&image->unuseable_pages);

}

static void kimage_terminate(struct kimage *image)

{

if (*image->entry != 0)

image->entry++;

*image->entry = IND_DONE;

}

#define for_each_kimage_entry(image, ptr, entry) \

for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \

ptr = (entry & IND_INDIRECTION)? \

phys_to_virt((entry & PAGE_MASK)): ptr +1)

static void kimage_free_entry(kimage_entry_t entry)

{

struct page *page;

page = pfn_to_page(entry >> PAGE_SHIFT);

kimage_free_pages(page);

}

static void kimage_free(struct kimage *image)

{

kimage_entry_t *ptr, entry;

kimage_entry_t ind = 0;

if (!image)

return;

kimage_free_extra_pages(image);

for_each_kimage_entry(image, ptr, entry) {

if (entry & IND_INDIRECTION) {

/* Free the previous indirection page */

if (ind & IND_INDIRECTION)

kimage_free_entry(ind);

/* Save this indirection page until we are

ind = entry;

}

else if (entry & IND_SOURCE)

kimage_free_entry(entry);

}

/* Free the final indirection page */

if (ind & IND_INDIRECTION)

kimage_free_entry(ind);

/* Handle any machine specific cleanup */

machine_kexec_cleanup(image);

/* Free the kexec control pages... */

kimage_free_page_list(&image->control_pages);

kfree(image);

}

static kimage_entry_t *kimage_dst_used(struct kimage *image,

unsigned long page)

{

kimage_entry_t *ptr, entry;

unsigned long destination = 0;

for_each_kimage_entry(image, ptr, entry) {

if (entry & IND_DESTINATION)

destination = entry & PAGE_MASK;

else if (entry & IND_SOURCE) {

if (page == destination)

return ptr;

destination += PAGE_SIZE;

}

}

return NULL;

}

static struct page *kimage_alloc_page(struct kimage *image,

gfp_t gfp_mask,

unsigned long destination)

{

/*

struct page *page;

unsigned long addr;

/*

list_for_each_entry(page, &image->dest_pages, lru) {

addr = page_to_pfn(page) << PAGE_SHIFT;

if (addr == destination) {

list_del(&page->lru);

return page;

}

}

page = NULL;

while (1) {

kimage_entry_t *old;

/* Allocate a page, if we run out of memory give up */

page = kimage_alloc_pages(gfp_mask, 0);

if (!page)

return NULL;

/* If the page cannot be used file it away */

if (page_to_pfn(page) >

(KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {

list_add(&page->lru, &image->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 */

if (!kimage_is_destination_range(image, addr,

addr + PAGE_SIZE))

break;

/*

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

if (!(gfp_mask & __GFP_HIGHMEM) &&

PageHighMem(old_page)) {

kimage_free_pages(old_page);

continue;

}

addr = old_addr;

page = old_page;

break;

}

else {

/* Place the page on the destination list I

list_add(&page->lru, &image->dest_pages);

}

}

return page;

}

static int kimage_load_normal_segment(struct kimage *image,

struct kexec_segment *segment)

{

unsigned long maddr;

size_t ubytes, mbytes;

int result;

unsigned char __user *buf;

result = 0;

buf = segment->buf;

ubytes = segment->bufsz;

mbytes = segment->memsz;

maddr = segment->mem;

result = kimage_set_destination(image, maddr);

if (result < 0)

goto out;

while (mbytes) {

struct page *page;

char *ptr;

size_t uchunk, mchunk;

page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);

if (!page) {

result = -ENOMEM;

goto out;

}

result = kimage_add_page(image, page_to_pfn(page)

<< PAGE_SHIFT);

if (result < 0)

goto out;

ptr = kmap(page);

/* Start with a clear page */

clear_page(ptr);

ptr += maddr & ~PAGE_MASK;

mchunk = min_t(size_t, mbytes,

PAGE_SIZE - (maddr & ~PAGE_MASK));

uchunk = min(ubytes, mchunk);

result = copy_from_user(ptr, buf, uchunk);

kunmap(page);

if (result) {

result = -EFAULT;

goto out;

}

ubytes -= uchunk;

maddr += mchunk;

buf += mchunk;

mbytes -= mchunk;

}

out:

return result;

}

static int kimage_load_crash_segment(struct kimage *image,

struct kexec_segment *segment)

{

/* For crash dumps kernels we simply copy the data from

unsigned long maddr;

size_t ubytes, mbytes;

int result;

unsigned char __user *buf;

result = 0;

buf = segment->buf;

ubytes = segment->bufsz;

mbytes = segment->memsz;

maddr = segment->mem;

while (mbytes) {

struct page *page;

char *ptr;

size_t uchunk, mchunk;

page = pfn_to_page(maddr >> PAGE_SHIFT);

if (!page) {

result = -ENOMEM;

goto out;

}

ptr = kmap(page);

ptr += maddr & ~PAGE_MASK;

mchunk = min_t(size_t, mbytes,

PAGE_SIZE - (maddr & ~PAGE_MASK));

uchunk = min(ubytes, mchunk);

if (mchunk > uchunk) {

/* Zero the trailing part of the page */

memset(ptr + uchunk, 0, mchunk - uchunk);

}

result = copy_from_user(ptr, buf, uchunk);

kexec_flush_icache_page(page);

kunmap(page);

if (result) {

result = -EFAULT;

goto out;

}

ubytes -= uchunk;

maddr += mchunk;

buf += mchunk;

mbytes -= mchunk;

}

out:

return result;

}

static int kimage_load_segment(struct kimage *image,

struct kexec_segment *segment)

{

int result = -ENOMEM;

switch (image->type) {

case KEXEC_TYPE_DEFAULT:

result = kimage_load_normal_segment(image, segment);

break;

case KEXEC_TYPE_CRASH:

result = kimage_load_crash_segment(image, segment);

break;

}

return result;

}

struct kimage *kexec_image;

struct kimage *kexec_crash_image;

static DEFINE_MUTEX(kexec_mutex);

SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,

struct kexec_segment __user *, segments, unsigned long, flags)

{

struct kimage **dest_image, *image;

int result;

/* We only trust the superuser with rebooting the system. */

if (!capable(CAP_SYS_BOOT))

return -EPERM;

/*

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

if (nr_segments > KEXEC_SEGMENT_MAX)

return -EINVAL;

image = NULL;

result = 0;

/* Because we write directly to the reserved memory

if (!mutex_trylock(&kexec_mutex))

return -EBUSY;

dest_image = &kexec_image;

if (flags & KEXEC_ON_CRASH)

dest_image = &kexec_crash_image;

if (nr_segments > 0) {

unsigned long i;

/* Loading another kernel to reboot into */

if ((flags & KEXEC_ON_CRASH) == 0)

result = kimage_normal_alloc(&image, entry,

nr_segments, segments);

/* Loading another kernel to switch to if this one crashes */

else if (flags & KEXEC_ON_CRASH) {

/* Free any current crash dump kernel before

kimage_free(xchg(&kexec_crash_image, NULL));

result = kimage_crash_alloc(&image, entry,

nr_segments, segments);

crash_map_reserved_pages();

}

if (result)