* Version 2. See the file COPYING for more details.
*/
+#include <linux/capability.h>
#include <linux/mm.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/highmem.h>
-#include <net/checksum.h>
+#include <linux/syscalls.h>
+#include <linux/reboot.h>
+#include <linux/syscalls.h>
+#include <linux/ioport.h>
+#include <linux/hardirq.h>
+
#include <asm/page.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/system.h>
+#include <asm/semaphore.h>
+
+/* Per cpu memory for storing cpu states in case of system crash. */
+note_buf_t* crash_notes;
+
+/* 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
+};
+
+int kexec_should_crash(struct task_struct *p)
+{
+ if (in_interrupt() || !p->pid || p->pid == 1 || panic_on_oops)
+ return 1;
+ return 0;
+}
/*
* When kexec transitions to the new kernel there is a one-to-one
*/
#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, unsigned int gfp_mask, unsigned long dest);
+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 kimage_alloc(struct kimage **rimage,
- unsigned long nr_segments, struct kexec_segment *segments)
+static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
+ unsigned long nr_segments,
+ struct kexec_segment __user *segments)
{
- int result;
- struct kimage *image;
size_t segment_bytes;
+ struct kimage *image;
unsigned long i;
+ int result;
/* Allocate a controlling structure */
result = -ENOMEM;
image = kmalloc(sizeof(*image), GFP_KERNEL);
- if (!image) {
+ if (!image)
goto out;
- }
+
memset(image, 0, sizeof(*image));
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);
/* Read in the segments */
image->nr_segments = nr_segments;
- segment_bytes = nr_segments * sizeof*segments;
+ segment_bytes = nr_segments * sizeof(*segments);
result = copy_from_user(image->segment, segments, segment_bytes);
if (result)
goto out;
* responsible for making certain we don't attempt to load
* the new image into invalid or reserved areas of RAM. This
* just verifies it is an address we can use.
+ *
+ * Since the kernel does everything in page size chunks ensure
+ * the destination addreses are page aligned. Too many
+ * special cases crop of when we don't do this. The most
+ * insidious is getting overlapping destination addresses
+ * simply because addresses are changed to page size
+ * granularity.
*/
result = -EADDRNOTAVAIL;
for (i = 0; i < nr_segments; i++) {
- unsigned long mend;
- mend = ((unsigned long)(image->segment[i].mem)) +
- image->segment[i].memsz;
+ 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.
+ * If we alloed overlapping destination addresses
+ * through very weird things can happen with no
+ * easy explanation as one segment stops on another.
+ */
+ result = -EINVAL;
+ for (i = 0; i < nr_segments; i++) {
+ unsigned long mstart, mend;
+ unsigned long j;
+
+ mstart = image->segment[i].mem;
+ mend = mstart + image->segment[i].memsz;
+ for (j = 0; j < i; j++) {
+ unsigned long pstart, pend;
+ pstart = image->segment[j].mem;
+ pend = pstart + image->segment[j].memsz;
+ /* Do the segments overlap ? */
+ if ((mend > pstart) && (mstart < pend))
+ 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;
+ 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 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;
+
+ *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
*/
result = -ENOMEM;
image->control_code_page = kimage_alloc_control_pages(image,
- get_order(KEXEC_CONTROL_CODE_SIZE));
+ get_order(KEXEC_CONTROL_CODE_SIZE));
if (!image->control_code_page) {
printk(KERN_ERR "Could not allocate control_code_buffer\n");
goto out;
result = 0;
out:
- if (result == 0) {
+ if (result == 0)
*rimage = image;
- } else {
+ else
kfree(image);
+
+ 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
+ * 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;
+
+ 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;
}
+
+ /*
+ * 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,
+ get_order(KEXEC_CONTROL_CODE_SIZE));
+ if (!image->control_code_page) {
+ printk(KERN_ERR "Could not allocate control_code_buffer\n");
+ goto out;
+ }
+
+ result = 0;
+out:
+ if (result == 0)
+ *rimage = image;
+ else
+ kfree(image);
+
return result;
}
-static int kimage_is_destination_range(
- struct kimage *image, unsigned long start, unsigned long end)
+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 = (unsigned long)image->segment[i].mem;
- mend = mstart + image->segment[i].memsz;
- if ((end > mstart) && (start < 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(unsigned int gfp_mask, unsigned int order)
+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;
- pages->private = order;
+ set_page_private(pages, order);
count = 1 << order;
- for(i = 0; i < count; i++) {
+ 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;
+
+ order = page_private(page);
count = 1 << order;
- for(i = 0; i < count; i++) {
+ 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);
}
}
-struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order)
+static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
+ unsigned int order)
{
/* Control pages are special, they are the intermediaries
* that are needed while we copy the rest of the pages
*/
do {
unsigned long pfn, epfn, addr, eaddr;
+
pages = kimage_alloc_pages(GFP_KERNEL, order);
if (!pages)
break;
addr = pfn << PAGE_SHIFT;
eaddr = epfn << PAGE_SHIFT;
if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
- kimage_is_destination_range(image, addr, eaddr))
- {
+ kimage_is_destination_range(image, addr, eaddr)) {
list_add(&pages->lru, &extra_pages);
pages = NULL;
}
- } while(!pages);
+ } while (!pages);
+
if (pages) {
/* Remember the allocated page... */
list_add(&pages->lru, &image->control_pages);
* For now it is simpler to just free the pages.
*/
kimage_free_page_list(&extra_pages);
+
+ return pages;
+}
+
+static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
+ unsigned int order)
+{
+ /* Control pages are special, they are the intermediaries
+ * that are needed while we copy the rest of the pages
+ * to their final resting place. As such they must
+ * not conflict with either the destination addresses
+ * or memory the kernel is already using.
+ *
+ * Control pages are also the only pags we must allocate
+ * when loading a crash kernel. All of the other pages
+ * are specified by the segments and we just memcpy
+ * into them directly.
+ *
+ * The only case where we really need more than one of
+ * these are for architectures where we cannot disable
+ * the MMU and must instead generate an identity mapped
+ * page table for all of the memory.
+ *
+ * Given the low demand this implements a very simple
+ * allocator that finds the first hole of the appropriate
+ * size in the reserved memory region, and allocates all
+ * of the memory up to and including the hole.
+ */
+ unsigned long hole_start, hole_end, size;
+ struct page *pages;
+
+ pages = NULL;
+ size = (1 << order) << PAGE_SHIFT;
+ hole_start = (image->control_page + (size - 1)) & ~(size - 1);
+ hole_end = hole_start + size - 1;
+ while (hole_end <= crashk_res.end) {
+ unsigned long i;
+
+ if (hole_end > KEXEC_CONTROL_MEMORY_LIMIT)
+ break;
+ if (hole_end > crashk_res.end)
+ 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) {
+ 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) {
+ 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->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)
+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) {
+ if (result == 0)
image->destination = destination;
- }
+
return result;
}
page &= PAGE_MASK;
result = kimage_add_entry(image, page | IND_SOURCE);
- if (result == 0) {
+ if (result == 0)
image->destination += PAGE_SIZE;
- }
+
return result;
}
}
static int kimage_terminate(struct kimage *image)
{
- int result;
+ if (*image->entry != 0)
+ image->entry++;
- result = kimage_add_entry(image, IND_DONE);
- if (result == 0) {
- /* Point at the terminating element */
- image->entry--;
- kimage_free_extra_pages(image);
- }
- return result;
+ *image->entry = IND_DONE;
+
+ return 0;
}
#define for_each_kimage_entry(image, ptr, entry) \
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) {
+ if (ind & IND_INDIRECTION)
kimage_free_entry(ind);
- }
/* Save this indirection page until we are
* done with it.
*/
ind = entry;
}
- else if (entry & IND_SOURCE) {
+ else if (entry & IND_SOURCE)
kimage_free_entry(entry);
- }
}
/* Free the final indirection page */
- if (ind & IND_INDIRECTION) {
+ if (ind & IND_INDIRECTION)
kimage_free_entry(ind);
- }
/* Handle any machine specific cleanup */
machine_kexec_cleanup(image);
kfree(image);
}
-static kimage_entry_t *kimage_dst_used(struct kimage *image, unsigned long page)
+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) {
+ if (entry & IND_DESTINATION)
destination = entry & PAGE_MASK;
- }
else if (entry & IND_SOURCE) {
- if (page == destination) {
+ if (page == destination)
return ptr;
- }
destination += PAGE_SIZE;
}
}
- return 0;
+
+ return NULL;
}
-static struct page *kimage_alloc_page(struct kimage *image, unsigned int gfp_mask, unsigned long destination)
+static struct page *kimage_alloc_page(struct kimage *image,
+ gfp_t gfp_mask,
+ unsigned long destination)
{
/*
* Here we implement safeguards to ensure that a source page
/* Allocate a page, if we run out of memory give up */
page = kimage_alloc_pages(gfp_mask, 0);
- if (!page) {
- return 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)) {
+ if (page_to_pfn(page) >
+ (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
list_add(&page->lru, &image->unuseable_pages);
continue;
}
break;
/* If the page is not a destination page use it */
- if (!kimage_is_destination_range(image, addr, addr + PAGE_SIZE))
+ if (!kimage_is_destination_range(image, addr,
+ addr + PAGE_SIZE))
break;
/*
list_add(&page->lru, &image->dest_pages);
}
}
+
return page;
}
-static int kimage_load_segment(struct kimage *image,
- struct kexec_segment *segment)
+static int kimage_load_normal_segment(struct kimage *image,
+ struct kexec_segment *segment)
{
- unsigned long mstart;
+ unsigned long maddr;
+ unsigned long ubytes, mbytes;
int result;
- unsigned long offset;
- unsigned long offset_end;
- unsigned char *buf;
+ unsigned char __user *buf;
result = 0;
buf = segment->buf;
- mstart = (unsigned long)segment->mem;
+ ubytes = segment->bufsz;
+ mbytes = segment->memsz;
+ maddr = segment->mem;
- offset_end = segment->memsz;
-
- result = kimage_set_destination(image, mstart);
- if (result < 0) {
+ result = kimage_set_destination(image, maddr);
+ if (result < 0)
goto out;
- }
- for (offset = 0; offset < segment->memsz; offset += PAGE_SIZE) {
+
+ while (mbytes) {
struct page *page;
char *ptr;
- size_t size, leader;
- page = kimage_alloc_page(image, GFP_HIGHUSER, mstart + offset);
+ size_t uchunk, mchunk;
+
+ page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
if (page == 0) {
result = -ENOMEM;
goto out;
}
- result = kimage_add_page(image, page_to_pfn(page) << PAGE_SHIFT);
- if (result < 0) {
+ result = kimage_add_page(image, page_to_pfn(page)
+ << PAGE_SHIFT);
+ if (result < 0)
goto out;
- }
+
ptr = kmap(page);
- if (segment->bufsz < offset) {
- /* We are past the end zero the whole page */
- memset(ptr, 0, PAGE_SIZE);
- kunmap(page);
- continue;
- }
- size = PAGE_SIZE;
- leader = 0;
- if ((offset == 0)) {
- leader = mstart & ~PAGE_MASK;
- }
- if (leader) {
- /* We are on the first page zero the unused portion */
- memset(ptr, 0, leader);
- size -= leader;
- ptr += leader;
+ /* Start with a clear page */
+ memset(ptr, 0, PAGE_SIZE);
+ ptr += maddr & ~PAGE_MASK;
+ mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
+ if (mchunk > mbytes)
+ mchunk = mbytes;
+
+ uchunk = mchunk;
+ if (uchunk > ubytes)
+ uchunk = ubytes;
+
+ result = copy_from_user(ptr, buf, uchunk);
+ kunmap(page);
+ if (result) {
+ result = (result < 0) ? result : -EIO;
+ goto out;
}
- if (size > (segment->bufsz - offset)) {
- size = segment->bufsz - offset;
+ 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
+ * 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;
+ 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 == 0) {
+ result = -ENOMEM;
+ goto out;
}
- if (size < (PAGE_SIZE - leader)) {
- /* zero the trailing part of the page */
- memset(ptr + size, 0, (PAGE_SIZE - leader) - size);
+ ptr = kmap(page);
+ ptr += maddr & ~PAGE_MASK;
+ mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
+ if (mchunk > mbytes)
+ mchunk = mbytes;
+
+ 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 + offset, size);
+ result = copy_from_user(ptr, buf, uchunk);
kunmap(page);
if (result) {
result = (result < 0) ? result : -EIO;
goto out;
}
+ ubytes -= uchunk;
+ maddr += mchunk;
+ buf += mchunk;
+ mbytes -= mchunk;
}
- out:
+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;
}
* that to happen you need to do that yourself.
*/
struct kimage *kexec_image = NULL;
+static struct kimage *kexec_crash_image = NULL;
+/*
+ * A home grown binary mutex.
+ * Nothing can wait so this mutex is safe to use
+ * in interrupt context :)
+ */
+static int kexec_lock = 0;
asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
- struct kexec_segment *segments, unsigned long flags)
+ struct kexec_segment __user *segments,
+ unsigned long flags)
{
- struct kimage *image;
+ struct kimage **dest_image, *image;
+ int locked;
int result;
/* We only trust the superuser with rebooting the system. */
return -EPERM;
/*
- * In case we need just a little bit of special behavior for
- * reboot on panic.
+ * Verify we have a legal set of flags
+ * This leaves us room for future extensions.
*/
- if (flags != 0)
+ 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.
+ */
+ locked = xchg(&kexec_lock, 1);
+ if (locked)
+ return -EBUSY;
+
+ dest_image = &kexec_image;
+ if (flags & KEXEC_ON_CRASH)
+ dest_image = &kexec_crash_image;
if (nr_segments > 0) {
unsigned long i;
- result = kimage_alloc(&image, nr_segments, segments);
- if (result) {
- goto out;
+
+ /* 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
+ * we corrupt it.
+ */
+ kimage_free(xchg(&kexec_crash_image, NULL));
+ result = kimage_crash_alloc(&image, entry,
+ nr_segments, segments);
}
+ if (result)
+ goto out;
+
result = machine_kexec_prepare(image);
- if (result) {
+ if (result)
goto out;
- }
- image->start = entry;
+
for (i = 0; i < nr_segments; i++) {
result = kimage_load_segment(image, &image->segment[i]);
- if (result) {
+ if (result)
goto out;
- }
}
result = kimage_terminate(image);
- if (result) {
+ if (result)
goto out;
- }
}
+ /* Install the new kernel, and Uninstall the old */
+ image = xchg(dest_image, image);
- image = xchg(&kexec_image, image);
-
- out:
+out:
+ xchg(&kexec_lock, 0); /* Release the mutex */
kimage_free(image);
+
return result;
}
+
+#ifdef CONFIG_COMPAT
+asmlinkage long compat_sys_kexec_load(unsigned long entry,
+ unsigned long nr_segments,
+ struct compat_kexec_segment __user *segments,
+ unsigned long flags)
+{
+ 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.
+ */
+ if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
+ return -EINVAL;
+
+ if (nr_segments > KEXEC_SEGMENT_MAX)
+ 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));
+ if (result)
+ 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));
+ if (result)
+ return -EFAULT;
+ }
+
+ return sys_kexec_load(entry, nr_segments, ksegments, flags);
+}
+#endif
+
+void crash_kexec(struct pt_regs *regs)
+{
+ struct kimage *image;
+ int locked;
+
+
+ /* Take the kexec_lock here to prevent sys_kexec_load
+ * running on one cpu from replacing the crash kernel
+ * we are using after a panic on a different cpu.
+ *
+ * If the crash kernel was not located in a fixed area
+ * of memory the xchg(&kexec_crash_image) would be
+ * sufficient. But since I reuse the memory...
+ */
+ locked = xchg(&kexec_lock, 1);
+ if (!locked) {
+ image = xchg(&kexec_crash_image, NULL);
+ if (image) {
+ struct pt_regs fixed_regs;
+ crash_setup_regs(&fixed_regs, regs);
+ machine_crash_shutdown(&fixed_regs);
+ machine_kexec(image);
+ }
+ xchg(&kexec_lock, 0);
+ }
+}
+
+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)
git://git.onelab.eu / linux-2.6.git / blobdiff